Initial import

1 files changed, 5583 insertions, 0 deletions

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
new file mode 100644
index 000000000..648a44675
--- /dev/null
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -0,0 +1,5583 @@
+/*
+ * Universal Flash Storage Host controller driver Core
+ *
+ * This code is based on drivers/scsi/ufs/ufshcd.c
+ * Copyright (C) 2011-2013 Samsung India Software Operations
+ * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ *
+ * Authors:
+ *	Santosh Yaraganavi <santosh.sy@samsung.com>
+ *	Vinayak Holikatti <h.vinayak@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * See the COPYING file in the top-level directory or visit
+ * <http://www.gnu.org/licenses/gpl-2.0.html>
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * This program is provided "AS IS" and "WITH ALL FAULTS" and
+ * without warranty of any kind. You are solely responsible for
+ * determining the appropriateness of using and distributing
+ * the program and assume all risks associated with your exercise
+ * of rights with respect to the program, including but not limited
+ * to infringement of third party rights, the risks and costs of
+ * program errors, damage to or loss of data, programs or equipment,
+ * and unavailability or interruption of operations. Under no
+ * circumstances will the contributor of this Program be liable for
+ * any damages of any kind arising from your use or distribution of
+ * this program.
+ *
+ * The Linux Foundation chooses to take subject only to the GPLv2
+ * license terms, and distributes only under these terms.
+ */
+
+#include <linux/async.h>
+#include <linux/devfreq.h>
+
+#include "ufshcd.h"
+#include "unipro.h"
+
+#define UFSHCD_ENABLE_INTRS	(UTP_TRANSFER_REQ_COMPL |\
+				 UTP_TASK_REQ_COMPL |\
+				 UFSHCD_ERROR_MASK)
+/* UIC command timeout, unit: ms */
+#define UIC_CMD_TIMEOUT	500
+
+/* NOP OUT retries waiting for NOP IN response */
+#define NOP_OUT_RETRIES    10
+/* Timeout after 30 msecs if NOP OUT hangs without response */
+#define NOP_OUT_TIMEOUT    30 /* msecs */
+
+/* Query request retries */
+#define QUERY_REQ_RETRIES 10
+/* Query request timeout */
+#define QUERY_REQ_TIMEOUT 30 /* msec */
+
+/* Task management command timeout */
+#define TM_CMD_TIMEOUT	100 /* msecs */
+
+/* maximum number of link-startup retries */
+#define DME_LINKSTARTUP_RETRIES 3
+
+/* maximum number of reset retries before giving up */
+#define MAX_HOST_RESET_RETRIES 5
+
+/* Expose the flag value from utp_upiu_query.value */
+#define MASK_QUERY_UPIU_FLAG_LOC 0xFF
+
+/* Interrupt aggregation default timeout, unit: 40us */
+#define INT_AGGR_DEF_TO	0x02
+
+#define ufshcd_toggle_vreg(_dev, _vreg, _on)				\
+	({                                                              \
+		int _ret;                                               \
+		if (_on)                                                \
+			_ret = ufshcd_enable_vreg(_dev, _vreg);         \
+		else                                                    \
+			_ret = ufshcd_disable_vreg(_dev, _vreg);        \
+		_ret;                                                   \
+	})
+
+static u32 ufs_query_desc_max_size[] = {
+	QUERY_DESC_DEVICE_MAX_SIZE,
+	QUERY_DESC_CONFIGURAION_MAX_SIZE,
+	QUERY_DESC_UNIT_MAX_SIZE,
+	QUERY_DESC_RFU_MAX_SIZE,
+	QUERY_DESC_INTERCONNECT_MAX_SIZE,
+	QUERY_DESC_STRING_MAX_SIZE,
+	QUERY_DESC_RFU_MAX_SIZE,
+	QUERY_DESC_GEOMETRY_MAZ_SIZE,
+	QUERY_DESC_POWER_MAX_SIZE,
+	QUERY_DESC_RFU_MAX_SIZE,
+};
+
+enum {
+	UFSHCD_MAX_CHANNEL	= 0,
+	UFSHCD_MAX_ID		= 1,
+	UFSHCD_CMD_PER_LUN	= 32,
+	UFSHCD_CAN_QUEUE	= 32,
+};
+
+/* UFSHCD states */
+enum {
+	UFSHCD_STATE_RESET,
+	UFSHCD_STATE_ERROR,
+	UFSHCD_STATE_OPERATIONAL,
+};
+
+/* UFSHCD error handling flags */
+enum {
+	UFSHCD_EH_IN_PROGRESS = (1 << 0),
+};
+
+/* UFSHCD UIC layer error flags */
+enum {
+	UFSHCD_UIC_DL_PA_INIT_ERROR = (1 << 0), /* Data link layer error */
+	UFSHCD_UIC_NL_ERROR = (1 << 1), /* Network layer error */
+	UFSHCD_UIC_TL_ERROR = (1 << 2), /* Transport Layer error */
+	UFSHCD_UIC_DME_ERROR = (1 << 3), /* DME error */
+};
+
+/* Interrupt configuration options */
+enum {
+	UFSHCD_INT_DISABLE,
+	UFSHCD_INT_ENABLE,
+	UFSHCD_INT_CLEAR,
+};
+
+#define ufshcd_set_eh_in_progress(h) \
+	(h->eh_flags |= UFSHCD_EH_IN_PROGRESS)
+#define ufshcd_eh_in_progress(h) \
+	(h->eh_flags & UFSHCD_EH_IN_PROGRESS)
+#define ufshcd_clear_eh_in_progress(h) \
+	(h->eh_flags &= ~UFSHCD_EH_IN_PROGRESS)
+
+#define ufshcd_set_ufs_dev_active(h) \
+	((h)->curr_dev_pwr_mode = UFS_ACTIVE_PWR_MODE)
+#define ufshcd_set_ufs_dev_sleep(h) \
+	((h)->curr_dev_pwr_mode = UFS_SLEEP_PWR_MODE)
+#define ufshcd_set_ufs_dev_poweroff(h) \
+	((h)->curr_dev_pwr_mode = UFS_POWERDOWN_PWR_MODE)
+#define ufshcd_is_ufs_dev_active(h) \
+	((h)->curr_dev_pwr_mode == UFS_ACTIVE_PWR_MODE)
+#define ufshcd_is_ufs_dev_sleep(h) \
+	((h)->curr_dev_pwr_mode == UFS_SLEEP_PWR_MODE)
+#define ufshcd_is_ufs_dev_poweroff(h) \
+	((h)->curr_dev_pwr_mode == UFS_POWERDOWN_PWR_MODE)
+
+static struct ufs_pm_lvl_states ufs_pm_lvl_states[] = {
+	{UFS_ACTIVE_PWR_MODE, UIC_LINK_ACTIVE_STATE},
+	{UFS_ACTIVE_PWR_MODE, UIC_LINK_HIBERN8_STATE},
+	{UFS_SLEEP_PWR_MODE, UIC_LINK_ACTIVE_STATE},
+	{UFS_SLEEP_PWR_MODE, UIC_LINK_HIBERN8_STATE},
+	{UFS_POWERDOWN_PWR_MODE, UIC_LINK_HIBERN8_STATE},
+	{UFS_POWERDOWN_PWR_MODE, UIC_LINK_OFF_STATE},
+};
+
+static inline enum ufs_dev_pwr_mode
+ufs_get_pm_lvl_to_dev_pwr_mode(enum ufs_pm_level lvl)
+{
+	return ufs_pm_lvl_states[lvl].dev_state;
+}
+
+static inline enum uic_link_state
+ufs_get_pm_lvl_to_link_pwr_state(enum ufs_pm_level lvl)
+{
+	return ufs_pm_lvl_states[lvl].link_state;
+}
+
+static void ufshcd_tmc_handler(struct ufs_hba *hba);
+static void ufshcd_async_scan(void *data, async_cookie_t cookie);
+static int ufshcd_reset_and_restore(struct ufs_hba *hba);
+static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag);
+static void ufshcd_hba_exit(struct ufs_hba *hba);
+static int ufshcd_probe_hba(struct ufs_hba *hba);
+static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
+				 bool skip_ref_clk);
+static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on);
+static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba);
+static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
+static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba);
+static int ufshcd_host_reset_and_restore(struct ufs_hba *hba);
+static irqreturn_t ufshcd_intr(int irq, void *__hba);
+static int ufshcd_config_pwr_mode(struct ufs_hba *hba,
+		struct ufs_pa_layer_attr *desired_pwr_mode);
+
+static inline int ufshcd_enable_irq(struct ufs_hba *hba)
+{
+	int ret = 0;
+
+	if (!hba->is_irq_enabled) {
+		ret = request_irq(hba->irq, ufshcd_intr, IRQF_SHARED, UFSHCD,
+				hba);
+		if (ret)
+			dev_err(hba->dev, "%s: request_irq failed, ret=%d\n",
+				__func__, ret);
+		hba->is_irq_enabled = true;
+	}
+
+	return ret;
+}
+
+static inline void ufshcd_disable_irq(struct ufs_hba *hba)
+{
+	if (hba->is_irq_enabled) {
+		free_irq(hba->irq, hba);
+		hba->is_irq_enabled = false;
+	}
+}
+
+/*
+ * ufshcd_wait_for_register - wait for register value to change
+ * @hba - per-adapter interface
+ * @reg - mmio register offset
+ * @mask - mask to apply to read register value
+ * @val - wait condition
+ * @interval_us - polling interval in microsecs
+ * @timeout_ms - timeout in millisecs
+ *
+ * Returns -ETIMEDOUT on error, zero on success
+ */
+static int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+		u32 val, unsigned long interval_us, unsigned long timeout_ms)
+{
+	int err = 0;
+	unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
+
+	/* ignore bits that we don't intend to wait on */
+	val = val & mask;
+
+	while ((ufshcd_readl(hba, reg) & mask) != val) {
+		/* wakeup within 50us of expiry */
+		usleep_range(interval_us, interval_us + 50);
+
+		if (time_after(jiffies, timeout)) {
+			if ((ufshcd_readl(hba, reg) & mask) != val)
+				err = -ETIMEDOUT;
+			break;
+		}
+	}
+
+	return err;
+}
+
+/**
+ * ufshcd_get_intr_mask - Get the interrupt bit mask
+ * @hba - Pointer to adapter instance
+ *
+ * Returns interrupt bit mask per version
+ */
+static inline u32 ufshcd_get_intr_mask(struct ufs_hba *hba)
+{
+	if (hba->ufs_version == UFSHCI_VERSION_10)
+		return INTERRUPT_MASK_ALL_VER_10;
+	else
+		return INTERRUPT_MASK_ALL_VER_11;
+}
+
+/**
+ * ufshcd_get_ufs_version - Get the UFS version supported by the HBA
+ * @hba - Pointer to adapter instance
+ *
+ * Returns UFSHCI version supported by the controller
+ */
+static inline u32 ufshcd_get_ufs_version(struct ufs_hba *hba)
+{
+	return ufshcd_readl(hba, REG_UFS_VERSION);
+}
+
+/**
+ * ufshcd_is_device_present - Check if any device connected to
+ *			      the host controller
+ * @hba: pointer to adapter instance
+ *
+ * Returns 1 if device present, 0 if no device detected
+ */
+static inline int ufshcd_is_device_present(struct ufs_hba *hba)
+{
+	return (ufshcd_readl(hba, REG_CONTROLLER_STATUS) &
+						DEVICE_PRESENT) ? 1 : 0;
+}
+
+/**
+ * ufshcd_get_tr_ocs - Get the UTRD Overall Command Status
+ * @lrb: pointer to local command reference block
+ *
+ * This function is used to get the OCS field from UTRD
+ * Returns the OCS field in the UTRD
+ */
+static inline int ufshcd_get_tr_ocs(struct ufshcd_lrb *lrbp)
+{
+	return le32_to_cpu(lrbp->utr_descriptor_ptr->header.dword_2) & MASK_OCS;
+}
+
+/**
+ * ufshcd_get_tmr_ocs - Get the UTMRD Overall Command Status
+ * @task_req_descp: pointer to utp_task_req_desc structure
+ *
+ * This function is used to get the OCS field from UTMRD
+ * Returns the OCS field in the UTMRD
+ */
+static inline int
+ufshcd_get_tmr_ocs(struct utp_task_req_desc *task_req_descp)
+{
+	return le32_to_cpu(task_req_descp->header.dword_2) & MASK_OCS;
+}
+
+/**
+ * ufshcd_get_tm_free_slot - get a free slot for task management request
+ * @hba: per adapter instance
+ * @free_slot: pointer to variable with available slot value
+ *
+ * Get a free tag and lock it until ufshcd_put_tm_slot() is called.
+ * Returns 0 if free slot is not available, else return 1 with tag value
+ * in @free_slot.
+ */
+static bool ufshcd_get_tm_free_slot(struct ufs_hba *hba, int *free_slot)
+{
+	int tag;
+	bool ret = false;
+
+	if (!free_slot)
+		goto out;
+
+	do {
+		tag = find_first_zero_bit(&hba->tm_slots_in_use, hba->nutmrs);
+		if (tag >= hba->nutmrs)
+			goto out;
+	} while (test_and_set_bit_lock(tag, &hba->tm_slots_in_use));
+
+	*free_slot = tag;
+	ret = true;
+out:
+	return ret;
+}
+
+static inline void ufshcd_put_tm_slot(struct ufs_hba *hba, int slot)
+{
+	clear_bit_unlock(slot, &hba->tm_slots_in_use);
+}
+
+/**
+ * ufshcd_utrl_clear - Clear a bit in UTRLCLR register
+ * @hba: per adapter instance
+ * @pos: position of the bit to be cleared
+ */
+static inline void ufshcd_utrl_clear(struct ufs_hba *hba, u32 pos)
+{
+	ufshcd_writel(hba, ~(1 << pos), REG_UTP_TRANSFER_REQ_LIST_CLEAR);
+}
+
+/**
+ * ufshcd_get_lists_status - Check UCRDY, UTRLRDY and UTMRLRDY
+ * @reg: Register value of host controller status
+ *
+ * Returns integer, 0 on Success and positive value if failed
+ */
+static inline int ufshcd_get_lists_status(u32 reg)
+{
+	/*
+	 * The mask 0xFF is for the following HCS register bits
+	 * Bit		Description
+	 *  0		Device Present
+	 *  1		UTRLRDY
+	 *  2		UTMRLRDY
+	 *  3		UCRDY
+	 *  4		HEI
+	 *  5		DEI
+	 * 6-7		reserved
+	 */
+	return (((reg) & (0xFF)) >> 1) ^ (0x07);
+}
+
+/**
+ * ufshcd_get_uic_cmd_result - Get the UIC command result
+ * @hba: Pointer to adapter instance
+ *
+ * This function gets the result of UIC command completion
+ * Returns 0 on success, non zero value on error
+ */
+static inline int ufshcd_get_uic_cmd_result(struct ufs_hba *hba)
+{
+	return ufshcd_readl(hba, REG_UIC_COMMAND_ARG_2) &
+	       MASK_UIC_COMMAND_RESULT;
+}
+
+/**
+ * ufshcd_get_dme_attr_val - Get the value of attribute returned by UIC command
+ * @hba: Pointer to adapter instance
+ *
+ * This function gets UIC command argument3
+ * Returns 0 on success, non zero value on error
+ */
+static inline u32 ufshcd_get_dme_attr_val(struct ufs_hba *hba)
+{
+	return ufshcd_readl(hba, REG_UIC_COMMAND_ARG_3);
+}
+
+/**
+ * ufshcd_get_req_rsp - returns the TR response transaction type
+ * @ucd_rsp_ptr: pointer to response UPIU
+ */
+static inline int
+ufshcd_get_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
+{
+	return be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24;
+}
+
+/**
+ * ufshcd_get_rsp_upiu_result - Get the result from response UPIU
+ * @ucd_rsp_ptr: pointer to response UPIU
+ *
+ * This function gets the response status and scsi_status from response UPIU
+ * Returns the response result code.
+ */
+static inline int
+ufshcd_get_rsp_upiu_result(struct utp_upiu_rsp *ucd_rsp_ptr)
+{
+	return be32_to_cpu(ucd_rsp_ptr->header.dword_1) & MASK_RSP_UPIU_RESULT;
+}
+
+/*
+ * ufshcd_get_rsp_upiu_data_seg_len - Get the data segment length
+ *				from response UPIU
+ * @ucd_rsp_ptr: pointer to response UPIU
+ *
+ * Return the data segment length.
+ */
+static inline unsigned int
+ufshcd_get_rsp_upiu_data_seg_len(struct utp_upiu_rsp *ucd_rsp_ptr)
+{
+	return be32_to_cpu(ucd_rsp_ptr->header.dword_2) &
+		MASK_RSP_UPIU_DATA_SEG_LEN;
+}
+
+/**
+ * ufshcd_is_exception_event - Check if the device raised an exception event
+ * @ucd_rsp_ptr: pointer to response UPIU
+ *
+ * The function checks if the device raised an exception event indicated in
+ * the Device Information field of response UPIU.
+ *
+ * Returns true if exception is raised, false otherwise.
+ */
+static inline bool ufshcd_is_exception_event(struct utp_upiu_rsp *ucd_rsp_ptr)
+{
+	return be32_to_cpu(ucd_rsp_ptr->header.dword_2) &
+			MASK_RSP_EXCEPTION_EVENT ? true : false;
+}
+
+/**
+ * ufshcd_reset_intr_aggr - Reset interrupt aggregation values.
+ * @hba: per adapter instance
+ */
+static inline void
+ufshcd_reset_intr_aggr(struct ufs_hba *hba)
+{
+	ufshcd_writel(hba, INT_AGGR_ENABLE |
+		      INT_AGGR_COUNTER_AND_TIMER_RESET,
+		      REG_UTP_TRANSFER_REQ_INT_AGG_CONTROL);
+}
+
+/**
+ * ufshcd_config_intr_aggr - Configure interrupt aggregation values.
+ * @hba: per adapter instance
+ * @cnt: Interrupt aggregation counter threshold
+ * @tmout: Interrupt aggregation timeout value
+ */
+static inline void
+ufshcd_config_intr_aggr(struct ufs_hba *hba, u8 cnt, u8 tmout)
+{
+	ufshcd_writel(hba, INT_AGGR_ENABLE | INT_AGGR_PARAM_WRITE |
+		      INT_AGGR_COUNTER_THLD_VAL(cnt) |
+		      INT_AGGR_TIMEOUT_VAL(tmout),
+		      REG_UTP_TRANSFER_REQ_INT_AGG_CONTROL);
+}
+
+/**
+ * ufshcd_enable_run_stop_reg - Enable run-stop registers,
+ *			When run-stop registers are set to 1, it indicates the
+ *			host controller that it can process the requests
+ * @hba: per adapter instance
+ */
+static void ufshcd_enable_run_stop_reg(struct ufs_hba *hba)
+{
+	ufshcd_writel(hba, UTP_TASK_REQ_LIST_RUN_STOP_BIT,
+		      REG_UTP_TASK_REQ_LIST_RUN_STOP);
+	ufshcd_writel(hba, UTP_TRANSFER_REQ_LIST_RUN_STOP_BIT,
+		      REG_UTP_TRANSFER_REQ_LIST_RUN_STOP);
+}
+
+/**
+ * ufshcd_hba_start - Start controller initialization sequence
+ * @hba: per adapter instance
+ */
+static inline void ufshcd_hba_start(struct ufs_hba *hba)
+{
+	ufshcd_writel(hba, CONTROLLER_ENABLE, REG_CONTROLLER_ENABLE);
+}
+
+/**
+ * ufshcd_is_hba_active - Get controller state
+ * @hba: per adapter instance
+ *
+ * Returns zero if controller is active, 1 otherwise
+ */
+static inline int ufshcd_is_hba_active(struct ufs_hba *hba)
+{
+	return (ufshcd_readl(hba, REG_CONTROLLER_ENABLE) & 0x1) ? 0 : 1;
+}
+
+static void ufshcd_ungate_work(struct work_struct *work)
+{
+	int ret;
+	unsigned long flags;
+	struct ufs_hba *hba = container_of(work, struct ufs_hba,
+			clk_gating.ungate_work);
+
+	cancel_delayed_work_sync(&hba->clk_gating.gate_work);
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (hba->clk_gating.state == CLKS_ON) {
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+		goto unblock_reqs;
+	}
+
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	ufshcd_setup_clocks(hba, true);
+
+	/* Exit from hibern8 */
+	if (ufshcd_can_hibern8_during_gating(hba)) {
+		/* Prevent gating in this path */
+		hba->clk_gating.is_suspended = true;
+		if (ufshcd_is_link_hibern8(hba)) {
+			ret = ufshcd_uic_hibern8_exit(hba);
+			if (ret)
+				dev_err(hba->dev, "%s: hibern8 exit failed %d\n",
+					__func__, ret);
+			else
+				ufshcd_set_link_active(hba);
+		}
+		hba->clk_gating.is_suspended = false;
+	}
+unblock_reqs:
+	if (ufshcd_is_clkscaling_enabled(hba))
+		devfreq_resume_device(hba->devfreq);
+	scsi_unblock_requests(hba->host);
+}
+
+/**
+ * ufshcd_hold - Enable clocks that were gated earlier due to ufshcd_release.
+ * Also, exit from hibern8 mode and set the link as active.
+ * @hba: per adapter instance
+ * @async: This indicates whether caller should ungate clocks asynchronously.
+ */
+int ufshcd_hold(struct ufs_hba *hba, bool async)
+{
+	int rc = 0;
+	unsigned long flags;
+
+	if (!ufshcd_is_clkgating_allowed(hba))
+		goto out;
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->clk_gating.active_reqs++;
+
+start:
+	switch (hba->clk_gating.state) {
+	case CLKS_ON:
+		break;
+	case REQ_CLKS_OFF:
+		if (cancel_delayed_work(&hba->clk_gating.gate_work)) {
+			hba->clk_gating.state = CLKS_ON;
+			break;
+		}
+		/*
+		 * If we here, it means gating work is either done or
+		 * currently running. Hence, fall through to cancel gating
+		 * work and to enable clocks.
+		 */
+	case CLKS_OFF:
+		scsi_block_requests(hba->host);
+		hba->clk_gating.state = REQ_CLKS_ON;
+		schedule_work(&hba->clk_gating.ungate_work);
+		/*
+		 * fall through to check if we should wait for this
+		 * work to be done or not.
+		 */
+	case REQ_CLKS_ON:
+		if (async) {
+			rc = -EAGAIN;
+			hba->clk_gating.active_reqs--;
+			break;
+		}
+
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+		flush_work(&hba->clk_gating.ungate_work);
+		/* Make sure state is CLKS_ON before returning */
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		goto start;
+	default:
+		dev_err(hba->dev, "%s: clk gating is in invalid state %d\n",
+				__func__, hba->clk_gating.state);
+		break;
+	}
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+out:
+	return rc;
+}
+
+static void ufshcd_gate_work(struct work_struct *work)
+{
+	struct ufs_hba *hba = container_of(work, struct ufs_hba,
+			clk_gating.gate_work.work);
+	unsigned long flags;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (hba->clk_gating.is_suspended) {
+		hba->clk_gating.state = CLKS_ON;
+		goto rel_lock;
+	}
+
+	if (hba->clk_gating.active_reqs
+		|| hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL
+		|| hba->lrb_in_use || hba->outstanding_tasks
+		|| hba->active_uic_cmd || hba->uic_async_done)
+		goto rel_lock;
+
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/* put the link into hibern8 mode before turning off clocks */
+	if (ufshcd_can_hibern8_during_gating(hba)) {
+		if (ufshcd_uic_hibern8_enter(hba)) {
+			hba->clk_gating.state = CLKS_ON;
+			goto out;
+		}
+		ufshcd_set_link_hibern8(hba);
+	}
+
+	if (ufshcd_is_clkscaling_enabled(hba)) {
+		devfreq_suspend_device(hba->devfreq);
+		hba->clk_scaling.window_start_t = 0;
+	}
+
+	if (!ufshcd_is_link_active(hba))
+		ufshcd_setup_clocks(hba, false);
+	else
+		/* If link is active, device ref_clk can't be switched off */
+		__ufshcd_setup_clocks(hba, false, true);
+
+	/*
+	 * In case you are here to cancel this work the gating state
+	 * would be marked as REQ_CLKS_ON. In this case keep the state
+	 * as REQ_CLKS_ON which would anyway imply that clocks are off
+	 * and a request to turn them on is pending. By doing this way,
+	 * we keep the state machine in tact and this would ultimately
+	 * prevent from doing cancel work multiple times when there are
+	 * new requests arriving before the current cancel work is done.
+	 */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (hba->clk_gating.state == REQ_CLKS_OFF)
+		hba->clk_gating.state = CLKS_OFF;
+
+rel_lock:
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+out:
+	return;
+}
+
+/* host lock must be held before calling this variant */
+static void __ufshcd_release(struct ufs_hba *hba)
+{
+	if (!ufshcd_is_clkgating_allowed(hba))
+		return;
+
+	hba->clk_gating.active_reqs--;
+
+	if (hba->clk_gating.active_reqs || hba->clk_gating.is_suspended
+		|| hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL
+		|| hba->lrb_in_use || hba->outstanding_tasks
+		|| hba->active_uic_cmd || hba->uic_async_done)
+		return;
+
+	hba->clk_gating.state = REQ_CLKS_OFF;
+	schedule_delayed_work(&hba->clk_gating.gate_work,
+			msecs_to_jiffies(hba->clk_gating.delay_ms));
+}
+
+void ufshcd_release(struct ufs_hba *hba)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	__ufshcd_release(hba);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+}
+
+static ssize_t ufshcd_clkgate_delay_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%lu\n", hba->clk_gating.delay_ms);
+}
+
+static ssize_t ufshcd_clkgate_delay_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	unsigned long flags, value;
+
+	if (kstrtoul(buf, 0, &value))
+		return -EINVAL;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->clk_gating.delay_ms = value;
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	return count;
+}
+
+static void ufshcd_init_clk_gating(struct ufs_hba *hba)
+{
+	if (!ufshcd_is_clkgating_allowed(hba))
+		return;
+
+	hba->clk_gating.delay_ms = 150;
+	INIT_DELAYED_WORK(&hba->clk_gating.gate_work, ufshcd_gate_work);
+	INIT_WORK(&hba->clk_gating.ungate_work, ufshcd_ungate_work);
+
+	hba->clk_gating.delay_attr.show = ufshcd_clkgate_delay_show;
+	hba->clk_gating.delay_attr.store = ufshcd_clkgate_delay_store;
+	sysfs_attr_init(&hba->clk_gating.delay_attr.attr);
+	hba->clk_gating.delay_attr.attr.name = "clkgate_delay_ms";
+	hba->clk_gating.delay_attr.attr.mode = S_IRUGO | S_IWUSR;
+	if (device_create_file(hba->dev, &hba->clk_gating.delay_attr))
+		dev_err(hba->dev, "Failed to create sysfs for clkgate_delay\n");
+}
+
+static void ufshcd_exit_clk_gating(struct ufs_hba *hba)
+{
+	if (!ufshcd_is_clkgating_allowed(hba))
+		return;
+	device_remove_file(hba->dev, &hba->clk_gating.delay_attr);
+	cancel_work_sync(&hba->clk_gating.ungate_work);
+	cancel_delayed_work_sync(&hba->clk_gating.gate_work);
+}
+
+/* Must be called with host lock acquired */
+static void ufshcd_clk_scaling_start_busy(struct ufs_hba *hba)
+{
+	if (!ufshcd_is_clkscaling_enabled(hba))
+		return;
+
+	if (!hba->clk_scaling.is_busy_started) {
+		hba->clk_scaling.busy_start_t = ktime_get();
+		hba->clk_scaling.is_busy_started = true;
+	}
+}
+
+static void ufshcd_clk_scaling_update_busy(struct ufs_hba *hba)
+{
+	struct ufs_clk_scaling *scaling = &hba->clk_scaling;
+
+	if (!ufshcd_is_clkscaling_enabled(hba))
+		return;
+
+	if (!hba->outstanding_reqs && scaling->is_busy_started) {
+		scaling->tot_busy_t += ktime_to_us(ktime_sub(ktime_get(),
+					scaling->busy_start_t));
+		scaling->busy_start_t = ktime_set(0, 0);
+		scaling->is_busy_started = false;
+	}
+}
+/**
+ * ufshcd_send_command - Send SCSI or device management commands
+ * @hba: per adapter instance
+ * @task_tag: Task tag of the command
+ */
+static inline
+void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
+{
+	ufshcd_clk_scaling_start_busy(hba);
+	__set_bit(task_tag, &hba->outstanding_reqs);
+	ufshcd_writel(hba, 1 << task_tag, REG_UTP_TRANSFER_REQ_DOOR_BELL);
+}
+
+/**
+ * ufshcd_copy_sense_data - Copy sense data in case of check condition
+ * @lrb - pointer to local reference block
+ */
+static inline void ufshcd_copy_sense_data(struct ufshcd_lrb *lrbp)
+{
+	int len;
+	if (lrbp->sense_buffer &&
+	    ufshcd_get_rsp_upiu_data_seg_len(lrbp->ucd_rsp_ptr)) {
+		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sr.sense_data_len);
+		memcpy(lrbp->sense_buffer,
+			lrbp->ucd_rsp_ptr->sr.sense_data,
+			min_t(int, len, SCSI_SENSE_BUFFERSIZE));
+	}
+}
+
+/**
+ * ufshcd_copy_query_response() - Copy the Query Response and the data
+ * descriptor
+ * @hba: per adapter instance
+ * @lrb - pointer to local reference block
+ */
+static
+int ufshcd_copy_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	struct ufs_query_res *query_res = &hba->dev_cmd.query.response;
+
+	memcpy(&query_res->upiu_res, &lrbp->ucd_rsp_ptr->qr, QUERY_OSF_SIZE);
+
+	/* Get the descriptor */
+	if (lrbp->ucd_rsp_ptr->qr.opcode == UPIU_QUERY_OPCODE_READ_DESC) {
+		u8 *descp = (u8 *)lrbp->ucd_rsp_ptr +
+				GENERAL_UPIU_REQUEST_SIZE;
+		u16 resp_len;
+		u16 buf_len;
+
+		/* data segment length */
+		resp_len = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_2) &
+						MASK_QUERY_DATA_SEG_LEN;
+		buf_len = be16_to_cpu(
+				hba->dev_cmd.query.request.upiu_req.length);
+		if (likely(buf_len >= resp_len)) {
+			memcpy(hba->dev_cmd.query.descriptor, descp, resp_len);
+		} else {
+			dev_warn(hba->dev,
+				"%s: Response size is bigger than buffer",
+				__func__);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * ufshcd_hba_capabilities - Read controller capabilities
+ * @hba: per adapter instance
+ */
+static inline void ufshcd_hba_capabilities(struct ufs_hba *hba)
+{
+	hba->capabilities = ufshcd_readl(hba, REG_CONTROLLER_CAPABILITIES);
+
+	/* nutrs and nutmrs are 0 based values */
+	hba->nutrs = (hba->capabilities & MASK_TRANSFER_REQUESTS_SLOTS) + 1;
+	hba->nutmrs =
+	((hba->capabilities & MASK_TASK_MANAGEMENT_REQUEST_SLOTS) >> 16) + 1;
+}
+
+/**
+ * ufshcd_ready_for_uic_cmd - Check if controller is ready
+ *                            to accept UIC commands
+ * @hba: per adapter instance
+ * Return true on success, else false
+ */
+static inline bool ufshcd_ready_for_uic_cmd(struct ufs_hba *hba)
+{
+	if (ufshcd_readl(hba, REG_CONTROLLER_STATUS) & UIC_COMMAND_READY)
+		return true;
+	else
+		return false;
+}
+
+/**
+ * ufshcd_get_upmcrs - Get the power mode change request status
+ * @hba: Pointer to adapter instance
+ *
+ * This function gets the UPMCRS field of HCS register
+ * Returns value of UPMCRS field
+ */
+static inline u8 ufshcd_get_upmcrs(struct ufs_hba *hba)
+{
+	return (ufshcd_readl(hba, REG_CONTROLLER_STATUS) >> 8) & 0x7;
+}
+
+/**
+ * ufshcd_dispatch_uic_cmd - Dispatch UIC commands to unipro layers
+ * @hba: per adapter instance
+ * @uic_cmd: UIC command
+ *
+ * Mutex must be held.
+ */
+static inline void
+ufshcd_dispatch_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
+{
+	WARN_ON(hba->active_uic_cmd);
+
+	hba->active_uic_cmd = uic_cmd;
+
+	/* Write Args */
+	ufshcd_writel(hba, uic_cmd->argument1, REG_UIC_COMMAND_ARG_1);
+	ufshcd_writel(hba, uic_cmd->argument2, REG_UIC_COMMAND_ARG_2);
+	ufshcd_writel(hba, uic_cmd->argument3, REG_UIC_COMMAND_ARG_3);
+
+	/* Write UIC Cmd */
+	ufshcd_writel(hba, uic_cmd->command & COMMAND_OPCODE_MASK,
+		      REG_UIC_COMMAND);
+}
+
+/**
+ * ufshcd_wait_for_uic_cmd - Wait complectioin of UIC command
+ * @hba: per adapter instance
+ * @uic_command: UIC command
+ *
+ * Must be called with mutex held.
+ * Returns 0 only if success.
+ */
+static int
+ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
+{
+	int ret;
+	unsigned long flags;
+
+	if (wait_for_completion_timeout(&uic_cmd->done,
+					msecs_to_jiffies(UIC_CMD_TIMEOUT)))
+		ret = uic_cmd->argument2 & MASK_UIC_COMMAND_RESULT;
+	else
+		ret = -ETIMEDOUT;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->active_uic_cmd = NULL;
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	return ret;
+}
+
+/**
+ * __ufshcd_send_uic_cmd - Send UIC commands and retrieve the result
+ * @hba: per adapter instance
+ * @uic_cmd: UIC command
+ *
+ * Identical to ufshcd_send_uic_cmd() expect mutex. Must be called
+ * with mutex held and host_lock locked.
+ * Returns 0 only if success.
+ */
+static int
+__ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
+{
+	if (!ufshcd_ready_for_uic_cmd(hba)) {
+		dev_err(hba->dev,
+			"Controller not ready to accept UIC commands\n");
+		return -EIO;
+	}
+
+	init_completion(&uic_cmd->done);
+
+	ufshcd_dispatch_uic_cmd(hba, uic_cmd);
+
+	return 0;
+}
+
+/**
+ * ufshcd_send_uic_cmd - Send UIC commands and retrieve the result
+ * @hba: per adapter instance
+ * @uic_cmd: UIC command
+ *
+ * Returns 0 only if success.
+ */
+static int
+ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
+{
+	int ret;
+	unsigned long flags;
+
+	ufshcd_hold(hba, false);
+	mutex_lock(&hba->uic_cmd_mutex);
+	ufshcd_add_delay_before_dme_cmd(hba);
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ret = __ufshcd_send_uic_cmd(hba, uic_cmd);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	if (!ret)
+		ret = ufshcd_wait_for_uic_cmd(hba, uic_cmd);
+
+	mutex_unlock(&hba->uic_cmd_mutex);
+
+	ufshcd_release(hba);
+	return ret;
+}
+
+/**
+ * ufshcd_map_sg - Map scatter-gather list to prdt
+ * @lrbp - pointer to local reference block
+ *
+ * Returns 0 in case of success, non-zero value in case of failure
+ */
+static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
+{
+	struct ufshcd_sg_entry *prd_table;
+	struct scatterlist *sg;
+	struct scsi_cmnd *cmd;
+	int sg_segments;
+	int i;
+
+	cmd = lrbp->cmd;
+	sg_segments = scsi_dma_map(cmd);
+	if (sg_segments < 0)
+		return sg_segments;
+
+	if (sg_segments) {
+		lrbp->utr_descriptor_ptr->prd_table_length =
+					cpu_to_le16((u16) (sg_segments));
+
+		prd_table = (struct ufshcd_sg_entry *)lrbp->ucd_prdt_ptr;
+
+		scsi_for_each_sg(cmd, sg, sg_segments, i) {
+			prd_table[i].size  =
+				cpu_to_le32(((u32) sg_dma_len(sg))-1);
+			prd_table[i].base_addr =
+				cpu_to_le32(lower_32_bits(sg->dma_address));
+			prd_table[i].upper_addr =
+				cpu_to_le32(upper_32_bits(sg->dma_address));
+		}
+	} else {
+		lrbp->utr_descriptor_ptr->prd_table_length = 0;
+	}
+
+	return 0;
+}
+
+/**
+ * ufshcd_enable_intr - enable interrupts
+ * @hba: per adapter instance
+ * @intrs: interrupt bits
+ */
+static void ufshcd_enable_intr(struct ufs_hba *hba, u32 intrs)
+{
+	u32 set = ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
+
+	if (hba->ufs_version == UFSHCI_VERSION_10) {
+		u32 rw;
+		rw = set & INTERRUPT_MASK_RW_VER_10;
+		set = rw | ((set ^ intrs) & intrs);
+	} else {
+		set |= intrs;
+	}
+
+	ufshcd_writel(hba, set, REG_INTERRUPT_ENABLE);
+}
+
+/**
+ * ufshcd_disable_intr - disable interrupts
+ * @hba: per adapter instance
+ * @intrs: interrupt bits
+ */
+static void ufshcd_disable_intr(struct ufs_hba *hba, u32 intrs)
+{
+	u32 set = ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
+
+	if (hba->ufs_version == UFSHCI_VERSION_10) {
+		u32 rw;
+		rw = (set & INTERRUPT_MASK_RW_VER_10) &
+			~(intrs & INTERRUPT_MASK_RW_VER_10);
+		set = rw | ((set & intrs) & ~INTERRUPT_MASK_RW_VER_10);
+
+	} else {
+		set &= ~intrs;
+	}
+
+	ufshcd_writel(hba, set, REG_INTERRUPT_ENABLE);
+}
+
+/**
+ * ufshcd_prepare_req_desc_hdr() - Fills the requests header
+ * descriptor according to request
+ * @lrbp: pointer to local reference block
+ * @upiu_flags: flags required in the header
+ * @cmd_dir: requests data direction
+ */
+static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
+		u32 *upiu_flags, enum dma_data_direction cmd_dir)
+{
+	struct utp_transfer_req_desc *req_desc = lrbp->utr_descriptor_ptr;
+	u32 data_direction;
+	u32 dword_0;
+
+	if (cmd_dir == DMA_FROM_DEVICE) {
+		data_direction = UTP_DEVICE_TO_HOST;
+		*upiu_flags = UPIU_CMD_FLAGS_READ;
+	} else if (cmd_dir == DMA_TO_DEVICE) {
+		data_direction = UTP_HOST_TO_DEVICE;
+		*upiu_flags = UPIU_CMD_FLAGS_WRITE;
+	} else {
+		data_direction = UTP_NO_DATA_TRANSFER;
+		*upiu_flags = UPIU_CMD_FLAGS_NONE;
+	}
+
+	dword_0 = data_direction | (lrbp->command_type
+				<< UPIU_COMMAND_TYPE_OFFSET);
+	if (lrbp->intr_cmd)
+		dword_0 |= UTP_REQ_DESC_INT_CMD;
+
+	/* Transfer request descriptor header fields */
+	req_desc->header.dword_0 = cpu_to_le32(dword_0);
+
+	/*
+	 * assigning invalid value for command status. Controller
+	 * updates OCS on command completion, with the command
+	 * status
+	 */
+	req_desc->header.dword_2 =
+		cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
+}
+
+/**
+ * ufshcd_prepare_utp_scsi_cmd_upiu() - fills the utp_transfer_req_desc,
+ * for scsi commands
+ * @lrbp - local reference block pointer
+ * @upiu_flags - flags
+ */
+static
+void ufshcd_prepare_utp_scsi_cmd_upiu(struct ufshcd_lrb *lrbp, u32 upiu_flags)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
+				UPIU_TRANSACTION_COMMAND, upiu_flags,
+				lrbp->lun, lrbp->task_tag);
+	ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
+				UPIU_COMMAND_SET_TYPE_SCSI, 0, 0, 0);
+
+	/* Total EHS length and Data segment length will be zero */
+	ucd_req_ptr->header.dword_2 = 0;
+
+	ucd_req_ptr->sc.exp_data_transfer_len =
+		cpu_to_be32(lrbp->cmd->sdb.length);
+
+	memcpy(ucd_req_ptr->sc.cdb, lrbp->cmd->cmnd,
+		(min_t(unsigned short, lrbp->cmd->cmd_len, MAX_CDB_SIZE)));
+}
+
+/**
+ * ufshcd_prepare_utp_query_req_upiu() - fills the utp_transfer_req_desc,
+ * for query requsts
+ * @hba: UFS hba
+ * @lrbp: local reference block pointer
+ * @upiu_flags: flags
+ */
+static void ufshcd_prepare_utp_query_req_upiu(struct ufs_hba *hba,
+				struct ufshcd_lrb *lrbp, u32 upiu_flags)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+	struct ufs_query *query = &hba->dev_cmd.query;
+	u16 len = be16_to_cpu(query->request.upiu_req.length);
+	u8 *descp = (u8 *)lrbp->ucd_req_ptr + GENERAL_UPIU_REQUEST_SIZE;
+
+	/* Query request header */
+	ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
+			UPIU_TRANSACTION_QUERY_REQ, upiu_flags,
+			lrbp->lun, lrbp->task_tag);
+	ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
+			0, query->request.query_func, 0, 0);
+
+	/* Data segment length */
+	ucd_req_ptr->header.dword_2 = UPIU_HEADER_DWORD(
+			0, 0, len >> 8, (u8)len);
+
+	/* Copy the Query Request buffer as is */
+	memcpy(&ucd_req_ptr->qr, &query->request.upiu_req,
+			QUERY_OSF_SIZE);
+
+	/* Copy the Descriptor */
+	if (query->request.upiu_req.opcode == UPIU_QUERY_OPCODE_WRITE_DESC)
+		memcpy(descp, query->descriptor, len);
+
+}
+
+static inline void ufshcd_prepare_utp_nop_upiu(struct ufshcd_lrb *lrbp)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	memset(ucd_req_ptr, 0, sizeof(struct utp_upiu_req));
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 =
+		UPIU_HEADER_DWORD(
+			UPIU_TRANSACTION_NOP_OUT, 0, 0, lrbp->task_tag);
+}
+
+/**
+ * ufshcd_compose_upiu - form UFS Protocol Information Unit(UPIU)
+ * @hba - per adapter instance
+ * @lrb - pointer to local reference block
+ */
+static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	u32 upiu_flags;
+	int ret = 0;
+
+	switch (lrbp->command_type) {
+	case UTP_CMD_TYPE_SCSI:
+		if (likely(lrbp->cmd)) {
+			ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags,
+					lrbp->cmd->sc_data_direction);
+			ufshcd_prepare_utp_scsi_cmd_upiu(lrbp, upiu_flags);
+		} else {
+			ret = -EINVAL;
+		}
+		break;
+	case UTP_CMD_TYPE_DEV_MANAGE:
+		ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
+		if (hba->dev_cmd.type == DEV_CMD_TYPE_QUERY)
+			ufshcd_prepare_utp_query_req_upiu(
+					hba, lrbp, upiu_flags);
+		else if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
+			ufshcd_prepare_utp_nop_upiu(lrbp);
+		else
+			ret = -EINVAL;
+		break;
+	case UTP_CMD_TYPE_UFS:
+		/* For UFS native command implementation */
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: UFS native command are not supported\n",
+			__func__);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: unknown command type: 0x%x\n",
+				__func__, lrbp->command_type);
+		break;
+	} /* end of switch */
+
+	return ret;
+}
+
+/*
+ * ufshcd_scsi_to_upiu_lun - maps scsi LUN to UPIU LUN
+ * @scsi_lun: scsi LUN id
+ *
+ * Returns UPIU LUN id
+ */
+static inline u8 ufshcd_scsi_to_upiu_lun(unsigned int scsi_lun)
+{
+	if (scsi_is_wlun(scsi_lun))
+		return (scsi_lun & UFS_UPIU_MAX_UNIT_NUM_ID)
+			| UFS_UPIU_WLUN_ID;
+	else
+		return scsi_lun & UFS_UPIU_MAX_UNIT_NUM_ID;
+}
+
+/**
+ * ufshcd_upiu_wlun_to_scsi_wlun - maps UPIU W-LUN id to SCSI W-LUN ID
+ * @scsi_lun: UPIU W-LUN id
+ *
+ * Returns SCSI W-LUN id
+ */
+static inline u16 ufshcd_upiu_wlun_to_scsi_wlun(u8 upiu_wlun_id)
+{
+	return (upiu_wlun_id & ~UFS_UPIU_WLUN_ID) | SCSI_W_LUN_BASE;
+}
+
+/**
+ * ufshcd_queuecommand - main entry point for SCSI requests
+ * @cmd: command from SCSI Midlayer
+ * @done: call back function
+ *
+ * Returns 0 for success, non-zero in case of failure
+ */
+static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
+{
+	struct ufshcd_lrb *lrbp;
+	struct ufs_hba *hba;
+	unsigned long flags;
+	int tag;
+	int err = 0;
+
+	hba = shost_priv(host);
+
+	tag = cmd->request->tag;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	switch (hba->ufshcd_state) {
+	case UFSHCD_STATE_OPERATIONAL:
+		break;
+	case UFSHCD_STATE_RESET:
+		err = SCSI_MLQUEUE_HOST_BUSY;
+		goto out_unlock;
+	case UFSHCD_STATE_ERROR:
+		set_host_byte(cmd, DID_ERROR);
+		cmd->scsi_done(cmd);
+		goto out_unlock;
+	default:
+		dev_WARN_ONCE(hba->dev, 1, "%s: invalid state %d\n",
+				__func__, hba->ufshcd_state);
+		set_host_byte(cmd, DID_BAD_TARGET);
+		cmd->scsi_done(cmd);
+		goto out_unlock;
+	}
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/* acquire the tag to make sure device cmds don't use it */
+	if (test_and_set_bit_lock(tag, &hba->lrb_in_use)) {
+		/*
+		 * Dev manage command in progress, requeue the command.
+		 * Requeuing the command helps in cases where the request *may*
+		 * find different tag instead of waiting for dev manage command
+		 * completion.
+		 */
+		err = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
+	err = ufshcd_hold(hba, true);
+	if (err) {
+		err = SCSI_MLQUEUE_HOST_BUSY;
+		clear_bit_unlock(tag, &hba->lrb_in_use);
+		goto out;
+	}
+	WARN_ON(hba->clk_gating.state != CLKS_ON);
+
+	lrbp = &hba->lrb[tag];
+
+	WARN_ON(lrbp->cmd);
+	lrbp->cmd = cmd;
+	lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
+	lrbp->sense_buffer = cmd->sense_buffer;
+	lrbp->task_tag = tag;
+	lrbp->lun = ufshcd_scsi_to_upiu_lun(cmd->device->lun);
+	lrbp->intr_cmd = false;
+	lrbp->command_type = UTP_CMD_TYPE_SCSI;
+
+	/* form UPIU before issuing the command */
+	ufshcd_compose_upiu(hba, lrbp);
+	err = ufshcd_map_sg(lrbp);
+	if (err) {
+		lrbp->cmd = NULL;
+		clear_bit_unlock(tag, &hba->lrb_in_use);
+		goto out;
+	}
+
+	/* issue command to the controller */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_send_command(hba, tag);
+out_unlock:
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+out:
+	return err;
+}
+
+static int ufshcd_compose_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, enum dev_cmd_type cmd_type, int tag)
+{
+	lrbp->cmd = NULL;
+	lrbp->sense_bufflen = 0;
+	lrbp->sense_buffer = NULL;
+	lrbp->task_tag = tag;
+	lrbp->lun = 0; /* device management cmd is not specific to any LUN */
+	lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
+	lrbp->intr_cmd = true; /* No interrupt aggregation */
+	hba->dev_cmd.type = cmd_type;
+
+	return ufshcd_compose_upiu(hba, lrbp);
+}
+
+static int
+ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
+{
+	int err = 0;
+	unsigned long flags;
+	u32 mask = 1 << tag;
+
+	/* clear outstanding transaction before retry */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_utrl_clear(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/*
+	 * wait for for h/w to clear corresponding bit in door-bell.
+	 * max. wait is 1 sec.
+	 */
+	err = ufshcd_wait_for_register(hba,
+			REG_UTP_TRANSFER_REQ_DOOR_BELL,
+			mask, ~mask, 1000, 1000);
+
+	return err;
+}
+
+static int
+ufshcd_check_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	struct ufs_query_res *query_res = &hba->dev_cmd.query.response;
+
+	/* Get the UPIU response */
+	query_res->response = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr) >>
+				UPIU_RSP_CODE_OFFSET;
+	return query_res->response;
+}
+
+/**
+ * ufshcd_dev_cmd_completion() - handles device management command responses
+ * @hba: per adapter instance
+ * @lrbp: pointer to local reference block
+ */
+static int
+ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	int resp;
+	int err = 0;
+
+	resp = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+	switch (resp) {
+	case UPIU_TRANSACTION_NOP_IN:
+		if (hba->dev_cmd.type != DEV_CMD_TYPE_NOP) {
+			err = -EINVAL;
+			dev_err(hba->dev, "%s: unexpected response %x\n",
+					__func__, resp);
+		}
+		break;
+	case UPIU_TRANSACTION_QUERY_RSP:
+		err = ufshcd_check_query_response(hba, lrbp);
+		if (!err)
+			err = ufshcd_copy_query_response(hba, lrbp);
+		break;
+	case UPIU_TRANSACTION_REJECT_UPIU:
+		/* TODO: handle Reject UPIU Response */
+		err = -EPERM;
+		dev_err(hba->dev, "%s: Reject UPIU not fully implemented\n",
+				__func__);
+		break;
+	default:
+		err = -EINVAL;
+		dev_err(hba->dev, "%s: Invalid device management cmd response: %x\n",
+				__func__, resp);
+		break;
+	}
+
+	return err;
+}
+
+static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, int max_timeout)
+{
+	int err = 0;
+	unsigned long time_left;
+	unsigned long flags;
+
+	time_left = wait_for_completion_timeout(hba->dev_cmd.complete,
+			msecs_to_jiffies(max_timeout));
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->dev_cmd.complete = NULL;
+	if (likely(time_left)) {
+		err = ufshcd_get_tr_ocs(lrbp);
+		if (!err)
+			err = ufshcd_dev_cmd_completion(hba, lrbp);
+	}
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	if (!time_left) {
+		err = -ETIMEDOUT;
+		if (!ufshcd_clear_cmd(hba, lrbp->task_tag))
+			/* sucessfully cleared the command, retry if needed */
+			err = -EAGAIN;
+	}
+
+	return err;
+}
+
+/**
+ * ufshcd_get_dev_cmd_tag - Get device management command tag
+ * @hba: per-adapter instance
+ * @tag: pointer to variable with available slot value
+ *
+ * Get a free slot and lock it until device management command
+ * completes.
+ *
+ * Returns false if free slot is unavailable for locking, else
+ * return true with tag value in @tag.
+ */
+static bool ufshcd_get_dev_cmd_tag(struct ufs_hba *hba, int *tag_out)
+{
+	int tag;
+	bool ret = false;
+	unsigned long tmp;
+
+	if (!tag_out)
+		goto out;
+
+	do {
+		tmp = ~hba->lrb_in_use;
+		tag = find_last_bit(&tmp, hba->nutrs);
+		if (tag >= hba->nutrs)
+			goto out;
+	} while (test_and_set_bit_lock(tag, &hba->lrb_in_use));
+
+	*tag_out = tag;
+	ret = true;
+out:
+	return ret;
+}
+
+static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag)
+{
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+}
+
+/**
+ * ufshcd_exec_dev_cmd - API for sending device management requests
+ * @hba - UFS hba
+ * @cmd_type - specifies the type (NOP, Query...)
+ * @timeout - time in seconds
+ *
+ * NOTE: Since there is only one available tag for device management commands,
+ * it is expected you hold the hba->dev_cmd.lock mutex.
+ */
+static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
+		enum dev_cmd_type cmd_type, int timeout)
+{
+	struct ufshcd_lrb *lrbp;
+	int err;
+	int tag;
+	struct completion wait;
+	unsigned long flags;
+
+	/*
+	 * Get free slot, sleep if slots are unavailable.
+	 * Even though we use wait_event() which sleeps indefinitely,
+	 * the maximum wait time is bounded by SCSI request timeout.
+	 */
+	wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));
+
+	init_completion(&wait);
+	lrbp = &hba->lrb[tag];
+	WARN_ON(lrbp->cmd);
+	err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag);
+	if (unlikely(err))
+		goto out_put_tag;
+
+	hba->dev_cmd.complete = &wait;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_send_command(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);
+
+out_put_tag:
+	ufshcd_put_dev_cmd_tag(hba, tag);
+	wake_up(&hba->dev_cmd.tag_wq);
+	return err;
+}
+
+/**
+ * ufshcd_init_query() - init the query response and request parameters
+ * @hba: per-adapter instance
+ * @request: address of the request pointer to be initialized
+ * @response: address of the response pointer to be initialized
+ * @opcode: operation to perform
+ * @idn: flag idn to access
+ * @index: LU number to access
+ * @selector: query/flag/descriptor further identification
+ */
+static inline void ufshcd_init_query(struct ufs_hba *hba,
+		struct ufs_query_req **request, struct ufs_query_res **response,
+		enum query_opcode opcode, u8 idn, u8 index, u8 selector)
+{
+	*request = &hba->dev_cmd.query.request;
+	*response = &hba->dev_cmd.query.response;
+	memset(*request, 0, sizeof(struct ufs_query_req));
+	memset(*response, 0, sizeof(struct ufs_query_res));
+	(*request)->upiu_req.opcode = opcode;
+	(*request)->upiu_req.idn = idn;
+	(*request)->upiu_req.index = index;
+	(*request)->upiu_req.selector = selector;
+}
+
+/**
+ * ufshcd_query_flag() - API function for sending flag query requests
+ * hba: per-adapter instance
+ * query_opcode: flag query to perform
+ * idn: flag idn to access
+ * flag_res: the flag value after the query request completes
+ *
+ * Returns 0 for success, non-zero in case of failure
+ */
+static int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
+			enum flag_idn idn, bool *flag_res)
+{
+	struct ufs_query_req *request = NULL;
+	struct ufs_query_res *response = NULL;
+	int err, index = 0, selector = 0;
+
+	BUG_ON(!hba);
+
+	ufshcd_hold(hba, false);
+	mutex_lock(&hba->dev_cmd.lock);
+	ufshcd_init_query(hba, &request, &response, opcode, idn, index,
+			selector);
+
+	switch (opcode) {
+	case UPIU_QUERY_OPCODE_SET_FLAG:
+	case UPIU_QUERY_OPCODE_CLEAR_FLAG:
+	case UPIU_QUERY_OPCODE_TOGGLE_FLAG:
+		request->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
+		break;
+	case UPIU_QUERY_OPCODE_READ_FLAG:
+		request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
+		if (!flag_res) {
+			/* No dummy reads */
+			dev_err(hba->dev, "%s: Invalid argument for read request\n",
+					__func__);
+			err = -EINVAL;
+			goto out_unlock;
+		}
+		break;
+	default:
+		dev_err(hba->dev,
+			"%s: Expected query flag opcode but got = %d\n",
+			__func__, opcode);
+		err = -EINVAL;
+		goto out_unlock;
+	}
+
+	err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);
+
+	if (err) {
+		dev_err(hba->dev,
+			"%s: Sending flag query for idn %d failed, err = %d\n",
+			__func__, idn, err);
+		goto out_unlock;
+	}
+
+	if (flag_res)
+		*flag_res = (be32_to_cpu(response->upiu_res.value) &
+				MASK_QUERY_UPIU_FLAG_LOC) & 0x1;
+
+out_unlock:
+	mutex_unlock(&hba->dev_cmd.lock);
+	ufshcd_release(hba);
+	return err;
+}
+
+/**
+ * ufshcd_query_attr - API function for sending attribute requests
+ * hba: per-adapter instance
+ * opcode: attribute opcode
+ * idn: attribute idn to access
+ * index: index field
+ * selector: selector field
+ * attr_val: the attribute value after the query request completes
+ *
+ * Returns 0 for success, non-zero in case of failure
+*/
+static int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
+			enum attr_idn idn, u8 index, u8 selector, u32 *attr_val)
+{
+	struct ufs_query_req *request = NULL;
+	struct ufs_query_res *response = NULL;
+	int err;
+
+	BUG_ON(!hba);
+
+	ufshcd_hold(hba, false);
+	if (!attr_val) {
+		dev_err(hba->dev, "%s: attribute value required for opcode 0x%x\n",
+				__func__, opcode);
+		err = -EINVAL;
+		goto out;
+	}
+
+	mutex_lock(&hba->dev_cmd.lock);
+	ufshcd_init_query(hba, &request, &response, opcode, idn, index,
+			selector);
+
+	switch (opcode) {
+	case UPIU_QUERY_OPCODE_WRITE_ATTR:
+		request->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
+		request->upiu_req.value = cpu_to_be32(*attr_val);
+		break;
+	case UPIU_QUERY_OPCODE_READ_ATTR:
+		request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
+		break;
+	default:
+		dev_err(hba->dev, "%s: Expected query attr opcode but got = 0x%.2x\n",
+				__func__, opcode);
+		err = -EINVAL;
+		goto out_unlock;
+	}
+
+	err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);
+
+	if (err) {
+		dev_err(hba->dev, "%s: opcode 0x%.2x for idn %d failed, err = %d\n",
+				__func__, opcode, idn, err);
+		goto out_unlock;
+	}
+
+	*attr_val = be32_to_cpu(response->upiu_res.value);
+
+out_unlock:
+	mutex_unlock(&hba->dev_cmd.lock);
+out:
+	ufshcd_release(hba);
+	return err;
+}
+
+/**
+ * ufshcd_query_descriptor - API function for sending descriptor requests
+ * hba: per-adapter instance
+ * opcode: attribute opcode
+ * idn: attribute idn to access
+ * index: index field
+ * selector: selector field
+ * desc_buf: the buffer that contains the descriptor
+ * buf_len: length parameter passed to the device
+ *
+ * Returns 0 for success, non-zero in case of failure.
+ * The buf_len parameter will contain, on return, the length parameter
+ * received on the response.
+ */
+static int ufshcd_query_descriptor(struct ufs_hba *hba,
+			enum query_opcode opcode, enum desc_idn idn, u8 index,
+			u8 selector, u8 *desc_buf, int *buf_len)
+{
+	struct ufs_query_req *request = NULL;
+	struct ufs_query_res *response = NULL;
+	int err;
+
+	BUG_ON(!hba);
+
+	ufshcd_hold(hba, false);
+	if (!desc_buf) {
+		dev_err(hba->dev, "%s: descriptor buffer required for opcode 0x%x\n",
+				__func__, opcode);
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (*buf_len <= QUERY_DESC_MIN_SIZE || *buf_len > QUERY_DESC_MAX_SIZE) {
+		dev_err(hba->dev, "%s: descriptor buffer size (%d) is out of range\n",
+				__func__, *buf_len);
+		err = -EINVAL;
+		goto out;
+	}
+
+	mutex_lock(&hba->dev_cmd.lock);
+	ufshcd_init_query(hba, &request, &response, opcode, idn, index,
+			selector);
+	hba->dev_cmd.query.descriptor = desc_buf;
+	request->upiu_req.length = cpu_to_be16(*buf_len);
+
+	switch (opcode) {
+	case UPIU_QUERY_OPCODE_WRITE_DESC:
+		request->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
+		break;
+	case UPIU_QUERY_OPCODE_READ_DESC:
+		request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
+		break;
+	default:
+		dev_err(hba->dev,
+				"%s: Expected query descriptor opcode but got = 0x%.2x\n",
+				__func__, opcode);
+		err = -EINVAL;
+		goto out_unlock;
+	}
+
+	err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);
+
+	if (err) {
+		dev_err(hba->dev, "%s: opcode 0x%.2x for idn %d failed, err = %d\n",
+				__func__, opcode, idn, err);
+		goto out_unlock;
+	}
+
+	hba->dev_cmd.query.descriptor = NULL;
+	*buf_len = be16_to_cpu(response->upiu_res.length);
+
+out_unlock:
+	mutex_unlock(&hba->dev_cmd.lock);
+out:
+	ufshcd_release(hba);
+	return err;
+}
+
+/**
+ * ufshcd_read_desc_param - read the specified descriptor parameter
+ * @hba: Pointer to adapter instance
+ * @desc_id: descriptor idn value
+ * @desc_index: descriptor index
+ * @param_offset: offset of the parameter to read
+ * @param_read_buf: pointer to buffer where parameter would be read
+ * @param_size: sizeof(param_read_buf)
+ *
+ * Return 0 in case of success, non-zero otherwise
+ */
+static int ufshcd_read_desc_param(struct ufs_hba *hba,
+				  enum desc_idn desc_id,
+				  int desc_index,
+				  u32 param_offset,
+				  u8 *param_read_buf,
+				  u32 param_size)
+{
+	int ret;
+	u8 *desc_buf;
+	u32 buff_len;
+	bool is_kmalloc = true;
+
+	/* safety checks */
+	if (desc_id >= QUERY_DESC_IDN_MAX)
+		return -EINVAL;
+
+	buff_len = ufs_query_desc_max_size[desc_id];
+	if ((param_offset + param_size) > buff_len)
+		return -EINVAL;
+
+	if (!param_offset && (param_size == buff_len)) {
+		/* memory space already available to hold full descriptor */
+		desc_buf = param_read_buf;
+		is_kmalloc = false;
+	} else {
+		/* allocate memory to hold full descriptor */
+		desc_buf = kmalloc(buff_len, GFP_KERNEL);
+		if (!desc_buf)
+			return -ENOMEM;
+	}
+
+	ret = ufshcd_query_descriptor(hba, UPIU_QUERY_OPCODE_READ_DESC,
+				      desc_id, desc_index, 0, desc_buf,
+				      &buff_len);
+
+	if (ret || (buff_len < ufs_query_desc_max_size[desc_id]) ||
+	    (desc_buf[QUERY_DESC_LENGTH_OFFSET] !=
+	     ufs_query_desc_max_size[desc_id])
+	    || (desc_buf[QUERY_DESC_DESC_TYPE_OFFSET] != desc_id)) {
+		dev_err(hba->dev, "%s: Failed reading descriptor. desc_id %d param_offset %d buff_len %d ret %d",
+			__func__, desc_id, param_offset, buff_len, ret);
+		if (!ret)
+			ret = -EINVAL;
+
+		goto out;
+	}
+
+	if (is_kmalloc)
+		memcpy(param_read_buf, &desc_buf[param_offset], param_size);
+out:
+	if (is_kmalloc)
+		kfree(desc_buf);
+	return ret;
+}
+
+static inline int ufshcd_read_desc(struct ufs_hba *hba,
+				   enum desc_idn desc_id,
+				   int desc_index,
+				   u8 *buf,
+				   u32 size)
+{
+	return ufshcd_read_desc_param(hba, desc_id, desc_index, 0, buf, size);
+}
+
+static inline int ufshcd_read_power_desc(struct ufs_hba *hba,
+					 u8 *buf,
+					 u32 size)
+{
+	return ufshcd_read_desc(hba, QUERY_DESC_IDN_POWER, 0, buf, size);
+}
+
+/**
+ * ufshcd_read_unit_desc_param - read the specified unit descriptor parameter
+ * @hba: Pointer to adapter instance
+ * @lun: lun id
+ * @param_offset: offset of the parameter to read
+ * @param_read_buf: pointer to buffer where parameter would be read
+ * @param_size: sizeof(param_read_buf)
+ *
+ * Return 0 in case of success, non-zero otherwise
+ */
+static inline int ufshcd_read_unit_desc_param(struct ufs_hba *hba,
+					      int lun,
+					      enum unit_desc_param param_offset,
+					      u8 *param_read_buf,
+					      u32 param_size)
+{
+	/*
+	 * Unit descriptors are only available for general purpose LUs (LUN id
+	 * from 0 to 7) and RPMB Well known LU.
+	 */
+	if (lun != UFS_UPIU_RPMB_WLUN && (lun >= UFS_UPIU_MAX_GENERAL_LUN))
+		return -EOPNOTSUPP;
+
+	return ufshcd_read_desc_param(hba, QUERY_DESC_IDN_UNIT, lun,
+				      param_offset, param_read_buf, param_size);
+}
+
+/**
+ * ufshcd_memory_alloc - allocate memory for host memory space data structures
+ * @hba: per adapter instance
+ *
+ * 1. Allocate DMA memory for Command Descriptor array
+ *	Each command descriptor consist of Command UPIU, Response UPIU and PRDT
+ * 2. Allocate DMA memory for UTP Transfer Request Descriptor List (UTRDL).
+ * 3. Allocate DMA memory for UTP Task Management Request Descriptor List
+ *	(UTMRDL)
+ * 4. Allocate memory for local reference block(lrb).
+ *
+ * Returns 0 for success, non-zero in case of failure
+ */
+static int ufshcd_memory_alloc(struct ufs_hba *hba)
+{
+	size_t utmrdl_size, utrdl_size, ucdl_size;
+
+	/* Allocate memory for UTP command descriptors */
+	ucdl_size = (sizeof(struct utp_transfer_cmd_desc) * hba->nutrs);
+	hba->ucdl_base_addr = dmam_alloc_coherent(hba->dev,
+						  ucdl_size,
+						  &hba->ucdl_dma_addr,
+						  GFP_KERNEL);
+
+	/*
+	 * UFSHCI requires UTP command descriptor to be 128 byte aligned.
+	 * make sure hba->ucdl_dma_addr is aligned to PAGE_SIZE
+	 * if hba->ucdl_dma_addr is aligned to PAGE_SIZE, then it will
+	 * be aligned to 128 bytes as well
+	 */
+	if (!hba->ucdl_base_addr ||
+	    WARN_ON(hba->ucdl_dma_addr & (PAGE_SIZE - 1))) {
+		dev_err(hba->dev,
+			"Command Descriptor Memory allocation failed\n");
+		goto out;
+	}
+
+	/*
+	 * Allocate memory for UTP Transfer descriptors
+	 * UFSHCI requires 1024 byte alignment of UTRD
+	 */
+	utrdl_size = (sizeof(struct utp_transfer_req_desc) * hba->nutrs);
+	hba->utrdl_base_addr = dmam_alloc_coherent(hba->dev,
+						   utrdl_size,
+						   &hba->utrdl_dma_addr,
+						   GFP_KERNEL);
+	if (!hba->utrdl_base_addr ||
+	    WARN_ON(hba->utrdl_dma_addr & (PAGE_SIZE - 1))) {
+		dev_err(hba->dev,
+			"Transfer Descriptor Memory allocation failed\n");
+		goto out;
+	}
+
+	/*
+	 * Allocate memory for UTP Task Management descriptors
+	 * UFSHCI requires 1024 byte alignment of UTMRD
+	 */
+	utmrdl_size = sizeof(struct utp_task_req_desc) * hba->nutmrs;
+	hba->utmrdl_base_addr = dmam_alloc_coherent(hba->dev,
+						    utmrdl_size,
+						    &hba->utmrdl_dma_addr,
+						    GFP_KERNEL);
+	if (!hba->utmrdl_base_addr ||
+	    WARN_ON(hba->utmrdl_dma_addr & (PAGE_SIZE - 1))) {
+		dev_err(hba->dev,
+		"Task Management Descriptor Memory allocation failed\n");
+		goto out;
+	}
+
+	/* Allocate memory for local reference block */
+	hba->lrb = devm_kzalloc(hba->dev,
+				hba->nutrs * sizeof(struct ufshcd_lrb),
+				GFP_KERNEL);
+	if (!hba->lrb) {
+		dev_err(hba->dev, "LRB Memory allocation failed\n");
+		goto out;
+	}
+	return 0;
+out:
+	return -ENOMEM;
+}
+
+/**
+ * ufshcd_host_memory_configure - configure local reference block with
+ *				memory offsets
+ * @hba: per adapter instance
+ *
+ * Configure Host memory space
+ * 1. Update Corresponding UTRD.UCDBA and UTRD.UCDBAU with UCD DMA
+ * address.
+ * 2. Update each UTRD with Response UPIU offset, Response UPIU length
+ * and PRDT offset.
+ * 3. Save the corresponding addresses of UTRD, UCD.CMD, UCD.RSP and UCD.PRDT
+ * into local reference block.
+ */
+static void ufshcd_host_memory_configure(struct ufs_hba *hba)
+{
+	struct utp_transfer_cmd_desc *cmd_descp;
+	struct utp_transfer_req_desc *utrdlp;
+	dma_addr_t cmd_desc_dma_addr;
+	dma_addr_t cmd_desc_element_addr;
+	u16 response_offset;
+	u16 prdt_offset;
+	int cmd_desc_size;
+	int i;
+
+	utrdlp = hba->utrdl_base_addr;
+	cmd_descp = hba->ucdl_base_addr;
+
+	response_offset =
+		offsetof(struct utp_transfer_cmd_desc, response_upiu);
+	prdt_offset =
+		offsetof(struct utp_transfer_cmd_desc, prd_table);
+
+	cmd_desc_size = sizeof(struct utp_transfer_cmd_desc);
+	cmd_desc_dma_addr = hba->ucdl_dma_addr;
+
+	for (i = 0; i < hba->nutrs; i++) {
+		/* Configure UTRD with command descriptor base address */
+		cmd_desc_element_addr =
+				(cmd_desc_dma_addr + (cmd_desc_size * i));
+		utrdlp[i].command_desc_base_addr_lo =
+				cpu_to_le32(lower_32_bits(cmd_desc_element_addr));
+		utrdlp[i].command_desc_base_addr_hi =
+				cpu_to_le32(upper_32_bits(cmd_desc_element_addr));
+
+		/* Response upiu and prdt offset should be in double words */
+		utrdlp[i].response_upiu_offset =
+				cpu_to_le16((response_offset >> 2));
+		utrdlp[i].prd_table_offset =
+				cpu_to_le16((prdt_offset >> 2));
+		utrdlp[i].response_upiu_length =
+				cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
+
+		hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
+		hba->lrb[i].ucd_req_ptr =
+			(struct utp_upiu_req *)(cmd_descp + i);
+		hba->lrb[i].ucd_rsp_ptr =
+			(struct utp_upiu_rsp *)cmd_descp[i].response_upiu;
+		hba->lrb[i].ucd_prdt_ptr =
+			(struct ufshcd_sg_entry *)cmd_descp[i].prd_table;
+	}
+}
+
+/**
+ * ufshcd_dme_link_startup - Notify Unipro to perform link startup
+ * @hba: per adapter instance
+ *
+ * UIC_CMD_DME_LINK_STARTUP command must be issued to Unipro layer,
+ * in order to initialize the Unipro link startup procedure.
+ * Once the Unipro links are up, the device connected to the controller
+ * is detected.
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+static int ufshcd_dme_link_startup(struct ufs_hba *hba)
+{
+	struct uic_command uic_cmd = {0};
+	int ret;
+
+	uic_cmd.command = UIC_CMD_DME_LINK_STARTUP;
+
+	ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
+	if (ret)
+		dev_err(hba->dev,
+			"dme-link-startup: error code %d\n", ret);
+	return ret;
+}
+
+static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba)
+{
+	#define MIN_DELAY_BEFORE_DME_CMDS_US	1000
+	unsigned long min_sleep_time_us;
+
+	if (!(hba->quirks & UFSHCD_QUIRK_DELAY_BEFORE_DME_CMDS))
+		return;
+
+	/*
+	 * last_dme_cmd_tstamp will be 0 only for 1st call to
+	 * this function
+	 */
+	if (unlikely(!ktime_to_us(hba->last_dme_cmd_tstamp))) {
+		min_sleep_time_us = MIN_DELAY_BEFORE_DME_CMDS_US;
+	} else {
+		unsigned long delta =
+			(unsigned long) ktime_to_us(
+				ktime_sub(ktime_get(),
+				hba->last_dme_cmd_tstamp));
+
+		if (delta < MIN_DELAY_BEFORE_DME_CMDS_US)
+			min_sleep_time_us =
+				MIN_DELAY_BEFORE_DME_CMDS_US - delta;
+		else
+			return; /* no more delay required */
+	}
+
+	/* allow sleep for extra 50us if needed */
+	usleep_range(min_sleep_time_us, min_sleep_time_us + 50);
+}
+
+/**
+ * ufshcd_dme_set_attr - UIC command for DME_SET, DME_PEER_SET
+ * @hba: per adapter instance
+ * @attr_sel: uic command argument1
+ * @attr_set: attribute set type as uic command argument2
+ * @mib_val: setting value as uic command argument3
+ * @peer: indicate whether peer or local
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+int ufshcd_dme_set_attr(struct ufs_hba *hba, u32 attr_sel,
+			u8 attr_set, u32 mib_val, u8 peer)
+{
+	struct uic_command uic_cmd = {0};
+	static const char *const action[] = {
+		"dme-set",
+		"dme-peer-set"
+	};
+	const char *set = action[!!peer];
+	int ret;
+
+	uic_cmd.command = peer ?
+		UIC_CMD_DME_PEER_SET : UIC_CMD_DME_SET;
+	uic_cmd.argument1 = attr_sel;
+	uic_cmd.argument2 = UIC_ARG_ATTR_TYPE(attr_set);
+	uic_cmd.argument3 = mib_val;
+
+	ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
+	if (ret)
+		dev_err(hba->dev, "%s: attr-id 0x%x val 0x%x error code %d\n",
+			set, UIC_GET_ATTR_ID(attr_sel), mib_val, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ufshcd_dme_set_attr);
+
+/**
+ * ufshcd_dme_get_attr - UIC command for DME_GET, DME_PEER_GET
+ * @hba: per adapter instance
+ * @attr_sel: uic command argument1
+ * @mib_val: the value of the attribute as returned by the UIC command
+ * @peer: indicate whether peer or local
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
+			u32 *mib_val, u8 peer)
+{
+	struct uic_command uic_cmd = {0};
+	static const char *const action[] = {
+		"dme-get",
+		"dme-peer-get"
+	};
+	const char *get = action[!!peer];
+	int ret;
+
+	uic_cmd.command = peer ?
+		UIC_CMD_DME_PEER_GET : UIC_CMD_DME_GET;
+	uic_cmd.argument1 = attr_sel;
+
+	ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
+	if (ret) {
+		dev_err(hba->dev, "%s: attr-id 0x%x error code %d\n",
+			get, UIC_GET_ATTR_ID(attr_sel), ret);
+		goto out;
+	}
+
+	if (mib_val)
+		*mib_val = uic_cmd.argument3;
+out:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ufshcd_dme_get_attr);
+
+/**
+ * ufshcd_uic_pwr_ctrl - executes UIC commands (which affects the link power
+ * state) and waits for it to take effect.
+ *
+ * @hba: per adapter instance
+ * @cmd: UIC command to execute
+ *
+ * DME operations like DME_SET(PA_PWRMODE), DME_HIBERNATE_ENTER &
+ * DME_HIBERNATE_EXIT commands take some time to take its effect on both host
+ * and device UniPro link and hence it's final completion would be indicated by
+ * dedicated status bits in Interrupt Status register (UPMS, UHES, UHXS) in
+ * addition to normal UIC command completion Status (UCCS). This function only
+ * returns after the relevant status bits indicate the completion.
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba, struct uic_command *cmd)
+{
+	struct completion uic_async_done;
+	unsigned long flags;
+	u8 status;
+	int ret;
+
+	mutex_lock(&hba->uic_cmd_mutex);
+	init_completion(&uic_async_done);
+	ufshcd_add_delay_before_dme_cmd(hba);
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->uic_async_done = &uic_async_done;
+	ret = __ufshcd_send_uic_cmd(hba, cmd);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	if (ret) {
+		dev_err(hba->dev,
+			"pwr ctrl cmd 0x%x with mode 0x%x uic error %d\n",
+			cmd->command, cmd->argument3, ret);
+		goto out;
+	}
+	ret = ufshcd_wait_for_uic_cmd(hba, cmd);
+	if (ret) {
+		dev_err(hba->dev,
+			"pwr ctrl cmd 0x%x with mode 0x%x uic error %d\n",
+			cmd->command, cmd->argument3, ret);
+		goto out;
+	}
+
+	if (!wait_for_completion_timeout(hba->uic_async_done,
+					 msecs_to_jiffies(UIC_CMD_TIMEOUT))) {
+		dev_err(hba->dev,
+			"pwr ctrl cmd 0x%x with mode 0x%x completion timeout\n",
+			cmd->command, cmd->argument3);
+		ret = -ETIMEDOUT;
+		goto out;
+	}
+
+	status = ufshcd_get_upmcrs(hba);
+	if (status != PWR_LOCAL) {
+		dev_err(hba->dev,
+			"pwr ctrl cmd 0x%0x failed, host umpcrs:0x%x\n",
+			cmd->command, status);
+		ret = (status != PWR_OK) ? status : -1;
+	}
+out:
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->uic_async_done = NULL;
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	mutex_unlock(&hba->uic_cmd_mutex);
+
+	return ret;
+}
+
+/**
+ * ufshcd_uic_change_pwr_mode - Perform the UIC power mode chage
+ *				using DME_SET primitives.
+ * @hba: per adapter instance
+ * @mode: powr mode value
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+static int ufshcd_uic_change_pwr_mode(struct ufs_hba *hba, u8 mode)
+{
+	struct uic_command uic_cmd = {0};
+	int ret;
+
+	uic_cmd.command = UIC_CMD_DME_SET;
+	uic_cmd.argument1 = UIC_ARG_MIB(PA_PWRMODE);
+	uic_cmd.argument3 = mode;
+	ufshcd_hold(hba, false);
+	ret = ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
+	ufshcd_release(hba);
+
+	return ret;
+}
+
+static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
+{
+	struct uic_command uic_cmd = {0};
+
+	uic_cmd.command = UIC_CMD_DME_HIBER_ENTER;
+
+	return ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
+}
+
+static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
+{
+	struct uic_command uic_cmd = {0};
+	int ret;
+
+	uic_cmd.command = UIC_CMD_DME_HIBER_EXIT;
+	ret = ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
+	if (ret) {
+		ufshcd_set_link_off(hba);
+		ret = ufshcd_host_reset_and_restore(hba);
+	}
+
+	return ret;
+}
+
+ /**
+ * ufshcd_init_pwr_info - setting the POR (power on reset)
+ * values in hba power info
+ * @hba: per-adapter instance
+ */
+static void ufshcd_init_pwr_info(struct ufs_hba *hba)
+{
+	hba->pwr_info.gear_rx = UFS_PWM_G1;
+	hba->pwr_info.gear_tx = UFS_PWM_G1;
+	hba->pwr_info.lane_rx = 1;
+	hba->pwr_info.lane_tx = 1;
+	hba->pwr_info.pwr_rx = SLOWAUTO_MODE;
+	hba->pwr_info.pwr_tx = SLOWAUTO_MODE;
+	hba->pwr_info.hs_rate = 0;
+}
+
+/**
+ * ufshcd_get_max_pwr_mode - reads the max power mode negotiated with device
+ * @hba: per-adapter instance
+ */
+static int ufshcd_get_max_pwr_mode(struct ufs_hba *hba)
+{
+	struct ufs_pa_layer_attr *pwr_info = &hba->max_pwr_info.info;
+
+	if (hba->max_pwr_info.is_valid)
+		return 0;
+
+	pwr_info->pwr_tx = FASTAUTO_MODE;
+	pwr_info->pwr_rx = FASTAUTO_MODE;
+	pwr_info->hs_rate = PA_HS_MODE_B;
+
+	/* Get the connected lane count */
+	ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDRXDATALANES),
+			&pwr_info->lane_rx);
+	ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDTXDATALANES),
+			&pwr_info->lane_tx);
+
+	if (!pwr_info->lane_rx || !pwr_info->lane_tx) {
+		dev_err(hba->dev, "%s: invalid connected lanes value. rx=%d, tx=%d\n",
+				__func__,
+				pwr_info->lane_rx,
+				pwr_info->lane_tx);
+		return -EINVAL;
+	}
+
+	/*
+	 * First, get the maximum gears of HS speed.
+	 * If a zero value, it means there is no HSGEAR capability.
+	 * Then, get the maximum gears of PWM speed.
+	 */
+	ufshcd_dme_get(hba, UIC_ARG_MIB(PA_MAXRXHSGEAR), &pwr_info->gear_rx);
+	if (!pwr_info->gear_rx) {
+		ufshcd_dme_get(hba, UIC_ARG_MIB(PA_MAXRXPWMGEAR),
+				&pwr_info->gear_rx);
+		if (!pwr_info->gear_rx) {
+			dev_err(hba->dev, "%s: invalid max pwm rx gear read = %d\n",
+				__func__, pwr_info->gear_rx);
+			return -EINVAL;
+		}
+		pwr_info->pwr_rx = SLOWAUTO_MODE;
+	}
+
+	ufshcd_dme_peer_get(hba, UIC_ARG_MIB(PA_MAXRXHSGEAR),
+			&pwr_info->gear_tx);
+	if (!pwr_info->gear_tx) {
+		ufshcd_dme_peer_get(hba, UIC_ARG_MIB(PA_MAXRXPWMGEAR),
+				&pwr_info->gear_tx);
+		if (!pwr_info->gear_tx) {
+			dev_err(hba->dev, "%s: invalid max pwm tx gear read = %d\n",
+				__func__, pwr_info->gear_tx);
+			return -EINVAL;
+		}
+		pwr_info->pwr_tx = SLOWAUTO_MODE;
+	}
+
+	hba->max_pwr_info.is_valid = true;
+	return 0;
+}
+
+static int ufshcd_change_power_mode(struct ufs_hba *hba,
+			     struct ufs_pa_layer_attr *pwr_mode)
+{
+	int ret;
+
+	/* if already configured to the requested pwr_mode */
+	if (pwr_mode->gear_rx == hba->pwr_info.gear_rx &&
+	    pwr_mode->gear_tx == hba->pwr_info.gear_tx &&
+	    pwr_mode->lane_rx == hba->pwr_info.lane_rx &&
+	    pwr_mode->lane_tx == hba->pwr_info.lane_tx &&
+	    pwr_mode->pwr_rx == hba->pwr_info.pwr_rx &&
+	    pwr_mode->pwr_tx == hba->pwr_info.pwr_tx &&
+	    pwr_mode->hs_rate == hba->pwr_info.hs_rate) {
+		dev_dbg(hba->dev, "%s: power already configured\n", __func__);
+		return 0;
+	}
+
+	/*
+	 * Configure attributes for power mode change with below.
+	 * - PA_RXGEAR, PA_ACTIVERXDATALANES, PA_RXTERMINATION,
+	 * - PA_TXGEAR, PA_ACTIVETXDATALANES, PA_TXTERMINATION,
+	 * - PA_HSSERIES
+	 */
+	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXGEAR), pwr_mode->gear_rx);
+	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_ACTIVERXDATALANES),
+			pwr_mode->lane_rx);
+	if (pwr_mode->pwr_rx == FASTAUTO_MODE ||
+			pwr_mode->pwr_rx == FAST_MODE)
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXTERMINATION), TRUE);
+	else
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXTERMINATION), FALSE);
+
+	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXGEAR), pwr_mode->gear_tx);
+	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_ACTIVETXDATALANES),
+			pwr_mode->lane_tx);
+	if (pwr_mode->pwr_tx == FASTAUTO_MODE ||
+			pwr_mode->pwr_tx == FAST_MODE)
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXTERMINATION), TRUE);
+	else
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXTERMINATION), FALSE);
+
+	if (pwr_mode->pwr_rx == FASTAUTO_MODE ||
+	    pwr_mode->pwr_tx == FASTAUTO_MODE ||
+	    pwr_mode->pwr_rx == FAST_MODE ||
+	    pwr_mode->pwr_tx == FAST_MODE)
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_HSSERIES),
+						pwr_mode->hs_rate);
+
+	ret = ufshcd_uic_change_pwr_mode(hba, pwr_mode->pwr_rx << 4
+			| pwr_mode->pwr_tx);
+
+	if (ret) {
+		dev_err(hba->dev,
+			"%s: power mode change failed %d\n", __func__, ret);
+	} else {
+		if (hba->vops && hba->vops->pwr_change_notify)
+			hba->vops->pwr_change_notify(hba,
+				POST_CHANGE, NULL, pwr_mode);
+
+		memcpy(&hba->pwr_info, pwr_mode,
+			sizeof(struct ufs_pa_layer_attr));
+	}
+
+	return ret;
+}
+
+/**
+ * ufshcd_config_pwr_mode - configure a new power mode
+ * @hba: per-adapter instance
+ * @desired_pwr_mode: desired power configuration
+ */
+static int ufshcd_config_pwr_mode(struct ufs_hba *hba,
+		struct ufs_pa_layer_attr *desired_pwr_mode)
+{
+	struct ufs_pa_layer_attr final_params = { 0 };
+	int ret;
+
+	if (hba->vops && hba->vops->pwr_change_notify)
+		hba->vops->pwr_change_notify(hba,
+		     PRE_CHANGE, desired_pwr_mode, &final_params);
+	else
+		memcpy(&final_params, desired_pwr_mode, sizeof(final_params));
+
+	ret = ufshcd_change_power_mode(hba, &final_params);
+
+	return ret;
+}
+
+/**
+ * ufshcd_complete_dev_init() - checks device readiness
+ * hba: per-adapter instance
+ *
+ * Set fDeviceInit flag and poll until device toggles it.
+ */
+static int ufshcd_complete_dev_init(struct ufs_hba *hba)
+{
+	int i, retries, err = 0;
+	bool flag_res = 1;
+
+	for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
+		/* Set the fDeviceInit flag */
+		err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_SET_FLAG,
+					QUERY_FLAG_IDN_FDEVICEINIT, NULL);
+		if (!err || err == -ETIMEDOUT)
+			break;
+		dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+	}
+	if (err) {
+		dev_err(hba->dev,
+			"%s setting fDeviceInit flag failed with error %d\n",
+			__func__, err);
+		goto out;
+	}
+
+	/* poll for max. 100 iterations for fDeviceInit flag to clear */
+	for (i = 0; i < 100 && !err && flag_res; i++) {
+		for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
+			err = ufshcd_query_flag(hba,
+					UPIU_QUERY_OPCODE_READ_FLAG,
+					QUERY_FLAG_IDN_FDEVICEINIT, &flag_res);
+			if (!err || err == -ETIMEDOUT)
+				break;
+			dev_dbg(hba->dev, "%s: error %d retrying\n", __func__,
+					err);
+		}
+	}
+	if (err)
+		dev_err(hba->dev,
+			"%s reading fDeviceInit flag failed with error %d\n",
+			__func__, err);
+	else if (flag_res)
+		dev_err(hba->dev,
+			"%s fDeviceInit was not cleared by the device\n",
+			__func__);
+
+out:
+	return err;
+}
+
+/**
+ * ufshcd_make_hba_operational - Make UFS controller operational
+ * @hba: per adapter instance
+ *
+ * To bring UFS host controller to operational state,
+ * 1. Enable required interrupts
+ * 2. Configure interrupt aggregation
+ * 3. Program UTRL and UTMRL base addres
+ * 4. Configure run-stop-registers
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+static int ufshcd_make_hba_operational(struct ufs_hba *hba)
+{
+	int err = 0;
+	u32 reg;
+
+	/* Enable required interrupts */
+	ufshcd_enable_intr(hba, UFSHCD_ENABLE_INTRS);
+
+	/* Configure interrupt aggregation */
+	ufshcd_config_intr_aggr(hba, hba->nutrs - 1, INT_AGGR_DEF_TO);
+
+	/* Configure UTRL and UTMRL base address registers */
+	ufshcd_writel(hba, lower_32_bits(hba->utrdl_dma_addr),
+			REG_UTP_TRANSFER_REQ_LIST_BASE_L);
+	ufshcd_writel(hba, upper_32_bits(hba->utrdl_dma_addr),
+			REG_UTP_TRANSFER_REQ_LIST_BASE_H);
+	ufshcd_writel(hba, lower_32_bits(hba->utmrdl_dma_addr),
+			REG_UTP_TASK_REQ_LIST_BASE_L);
+	ufshcd_writel(hba, upper_32_bits(hba->utmrdl_dma_addr),
+			REG_UTP_TASK_REQ_LIST_BASE_H);
+
+	/*
+	 * UCRDY, UTMRLDY and UTRLRDY bits must be 1
+	 * DEI, HEI bits must be 0
+	 */
+	reg = ufshcd_readl(hba, REG_CONTROLLER_STATUS);
+	if (!(ufshcd_get_lists_status(reg))) {
+		ufshcd_enable_run_stop_reg(hba);
+	} else {
+		dev_err(hba->dev,
+			"Host controller not ready to process requests");
+		err = -EIO;
+		goto out;
+	}
+
+out:
+	return err;
+}
+
+/**
+ * ufshcd_hba_enable - initialize the controller
+ * @hba: per adapter instance
+ *
+ * The controller resets itself and controller firmware initialization
+ * sequence kicks off. When controller is ready it will set
+ * the Host Controller Enable bit to 1.
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+static int ufshcd_hba_enable(struct ufs_hba *hba)
+{
+	int retry;
+
+	/*
+	 * msleep of 1 and 5 used in this function might result in msleep(20),
+	 * but it was necessary to send the UFS FPGA to reset mode during
+	 * development and testing of this driver. msleep can be changed to
+	 * mdelay and retry count can be reduced based on the controller.
+	 */
+	if (!ufshcd_is_hba_active(hba)) {
+
+		/* change controller state to "reset state" */
+		ufshcd_hba_stop(hba);
+
+		/*
+		 * This delay is based on the testing done with UFS host
+		 * controller FPGA. The delay can be changed based on the
+		 * host controller used.
+		 */
+		msleep(5);
+	}
+
+	/* UniPro link is disabled at this point */
+	ufshcd_set_link_off(hba);
+
+	if (hba->vops && hba->vops->hce_enable_notify)
+		hba->vops->hce_enable_notify(hba, PRE_CHANGE);
+
+	/* start controller initialization sequence */
+	ufshcd_hba_start(hba);
+
+	/*
+	 * To initialize a UFS host controller HCE bit must be set to 1.
+	 * During initialization the HCE bit value changes from 1->0->1.
+	 * When the host controller completes initialization sequence
+	 * it sets the value of HCE bit to 1. The same HCE bit is read back
+	 * to check if the controller has completed initialization sequence.
+	 * So without this delay the value HCE = 1, set in the previous
+	 * instruction might be read back.
+	 * This delay can be changed based on the controller.
+	 */
+	msleep(1);
+
+	/* wait for the host controller to complete initialization */
+	retry = 10;
+	while (ufshcd_is_hba_active(hba)) {
+		if (retry) {
+			retry--;
+		} else {
+			dev_err(hba->dev,
+				"Controller enable failed\n");
+			return -EIO;
+		}
+		msleep(5);
+	}
+
+	/* enable UIC related interrupts */
+	ufshcd_enable_intr(hba, UFSHCD_UIC_MASK);
+
+	if (hba->vops && hba->vops->hce_enable_notify)
+		hba->vops->hce_enable_notify(hba, POST_CHANGE);
+
+	return 0;
+}
+
+/**
+ * ufshcd_link_startup - Initialize unipro link startup
+ * @hba: per adapter instance
+ *
+ * Returns 0 for success, non-zero in case of failure
+ */
+static int ufshcd_link_startup(struct ufs_hba *hba)
+{
+	int ret;
+	int retries = DME_LINKSTARTUP_RETRIES;
+
+	do {
+		if (hba->vops && hba->vops->link_startup_notify)
+			hba->vops->link_startup_notify(hba, PRE_CHANGE);
+
+		ret = ufshcd_dme_link_startup(hba);
+
+		/* check if device is detected by inter-connect layer */
+		if (!ret && !ufshcd_is_device_present(hba)) {
+			dev_err(hba->dev, "%s: Device not present\n", __func__);
+			ret = -ENXIO;
+			goto out;
+		}
+
+		/*
+		 * DME link lost indication is only received when link is up,
+		 * but we can't be sure if the link is up until link startup
+		 * succeeds. So reset the local Uni-Pro and try again.
+		 */
+		if (ret && ufshcd_hba_enable(hba))
+			goto out;
+	} while (ret && retries--);
+
+	if (ret)
+		/* failed to get the link up... retire */
+		goto out;
+
+	/* Include any host controller configuration via UIC commands */
+	if (hba->vops && hba->vops->link_startup_notify) {
+		ret = hba->vops->link_startup_notify(hba, POST_CHANGE);
+		if (ret)
+			goto out;
+	}
+
+	ret = ufshcd_make_hba_operational(hba);
+out:
+	if (ret)
+		dev_err(hba->dev, "link startup failed %d\n", ret);
+	return ret;
+}
+
+/**
+ * ufshcd_verify_dev_init() - Verify device initialization
+ * @hba: per-adapter instance
+ *
+ * Send NOP OUT UPIU and wait for NOP IN response to check whether the
+ * device Transport Protocol (UTP) layer is ready after a reset.
+ * If the UTP layer at the device side is not initialized, it may
+ * not respond with NOP IN UPIU within timeout of %NOP_OUT_TIMEOUT
+ * and we retry sending NOP OUT for %NOP_OUT_RETRIES iterations.
+ */
+static int ufshcd_verify_dev_init(struct ufs_hba *hba)
+{
+	int err = 0;
+	int retries;
+
+	ufshcd_hold(hba, false);
+	mutex_lock(&hba->dev_cmd.lock);
+	for (retries = NOP_OUT_RETRIES; retries > 0; retries--) {
+		err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_NOP,
+					       NOP_OUT_TIMEOUT);
+
+		if (!err || err == -ETIMEDOUT)
+			break;
+
+		dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+	}
+	mutex_unlock(&hba->dev_cmd.lock);
+	ufshcd_release(hba);
+
+	if (err)
+		dev_err(hba->dev, "%s: NOP OUT failed %d\n", __func__, err);
+	return err;
+}
+
+/**
+ * ufshcd_set_queue_depth - set lun queue depth
+ * @sdev: pointer to SCSI device
+ *
+ * Read bLUQueueDepth value and activate scsi tagged command
+ * queueing. For WLUN, queue depth is set to 1. For best-effort
+ * cases (bLUQueueDepth = 0) the queue depth is set to a maximum
+ * value that host can queue.
+ */
+static void ufshcd_set_queue_depth(struct scsi_device *sdev)
+{
+	int ret = 0;
+	u8 lun_qdepth;
+	struct ufs_hba *hba;
+
+	hba = shost_priv(sdev->host);
+
+	lun_qdepth = hba->nutrs;
+	ret = ufshcd_read_unit_desc_param(hba,
+					  ufshcd_scsi_to_upiu_lun(sdev->lun),
+					  UNIT_DESC_PARAM_LU_Q_DEPTH,
+					  &lun_qdepth,
+					  sizeof(lun_qdepth));
+
+	/* Some WLUN doesn't support unit descriptor */
+	if (ret == -EOPNOTSUPP)
+		lun_qdepth = 1;
+	else if (!lun_qdepth)
+		/* eventually, we can figure out the real queue depth */
+		lun_qdepth = hba->nutrs;
+	else
+		lun_qdepth = min_t(int, lun_qdepth, hba->nutrs);
+
+	dev_dbg(hba->dev, "%s: activate tcq with queue depth %d\n",
+			__func__, lun_qdepth);
+	scsi_change_queue_depth(sdev, lun_qdepth);
+}
+
+/*
+ * ufshcd_get_lu_wp - returns the "b_lu_write_protect" from UNIT DESCRIPTOR
+ * @hba: per-adapter instance
+ * @lun: UFS device lun id
+ * @b_lu_write_protect: pointer to buffer to hold the LU's write protect info
+ *
+ * Returns 0 in case of success and b_lu_write_protect status would be returned
+ * @b_lu_write_protect parameter.
+ * Returns -ENOTSUPP if reading b_lu_write_protect is not supported.
+ * Returns -EINVAL in case of invalid parameters passed to this function.
+ */
+static int ufshcd_get_lu_wp(struct ufs_hba *hba,
+			    u8 lun,
+			    u8 *b_lu_write_protect)
+{
+	int ret;
+
+	if (!b_lu_write_protect)
+		ret = -EINVAL;
+	/*
+	 * According to UFS device spec, RPMB LU can't be write
+	 * protected so skip reading bLUWriteProtect parameter for
+	 * it. For other W-LUs, UNIT DESCRIPTOR is not available.
+	 */
+	else if (lun >= UFS_UPIU_MAX_GENERAL_LUN)
+		ret = -ENOTSUPP;
+	else
+		ret = ufshcd_read_unit_desc_param(hba,
+					  lun,
+					  UNIT_DESC_PARAM_LU_WR_PROTECT,
+					  b_lu_write_protect,
+					  sizeof(*b_lu_write_protect));
+	return ret;
+}
+
+/**
+ * ufshcd_get_lu_power_on_wp_status - get LU's power on write protect
+ * status
+ * @hba: per-adapter instance
+ * @sdev: pointer to SCSI device
+ *
+ */
+static inline void ufshcd_get_lu_power_on_wp_status(struct ufs_hba *hba,
+						    struct scsi_device *sdev)
+{
+	if (hba->dev_info.f_power_on_wp_en &&
+	    !hba->dev_info.is_lu_power_on_wp) {
+		u8 b_lu_write_protect;
+
+		if (!ufshcd_get_lu_wp(hba, ufshcd_scsi_to_upiu_lun(sdev->lun),
+				      &b_lu_write_protect) &&
+		    (b_lu_write_protect == UFS_LU_POWER_ON_WP))
+			hba->dev_info.is_lu_power_on_wp = true;
+	}
+}
+
+/**
+ * ufshcd_slave_alloc - handle initial SCSI device configurations
+ * @sdev: pointer to SCSI device
+ *
+ * Returns success
+ */
+static int ufshcd_slave_alloc(struct scsi_device *sdev)
+{
+	struct ufs_hba *hba;
+
+	hba = shost_priv(sdev->host);
+
+	/* Mode sense(6) is not supported by UFS, so use Mode sense(10) */
+	sdev->use_10_for_ms = 1;
+
+	/* allow SCSI layer to restart the device in case of errors */
+	sdev->allow_restart = 1;
+
+	/* REPORT SUPPORTED OPERATION CODES is not supported */
+	sdev->no_report_opcodes = 1;
+
+
+	ufshcd_set_queue_depth(sdev);
+
+	ufshcd_get_lu_power_on_wp_status(hba, sdev);
+
+	return 0;
+}
+
+/**
+ * ufshcd_change_queue_depth - change queue depth
+ * @sdev: pointer to SCSI device
+ * @depth: required depth to set
+ *
+ * Change queue depth and make sure the max. limits are not crossed.
+ */
+static int ufshcd_change_queue_depth(struct scsi_device *sdev, int depth)
+{
+	struct ufs_hba *hba = shost_priv(sdev->host);
+
+	if (depth > hba->nutrs)
+		depth = hba->nutrs;
+	return scsi_change_queue_depth(sdev, depth);
+}
+
+/**
+ * ufshcd_slave_configure - adjust SCSI device configurations
+ * @sdev: pointer to SCSI device
+ */
+static int ufshcd_slave_configure(struct scsi_device *sdev)
+{
+	struct request_queue *q = sdev->request_queue;
+
+	blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
+	blk_queue_max_segment_size(q, PRDT_DATA_BYTE_COUNT_MAX);
+
+	return 0;
+}
+
+/**
+ * ufshcd_slave_destroy - remove SCSI device configurations
+ * @sdev: pointer to SCSI device
+ */
+static void ufshcd_slave_destroy(struct scsi_device *sdev)
+{
+	struct ufs_hba *hba;
+
+	hba = shost_priv(sdev->host);
+	/* Drop the reference as it won't be needed anymore */
+	if (ufshcd_scsi_to_upiu_lun(sdev->lun) == UFS_UPIU_UFS_DEVICE_WLUN) {
+		unsigned long flags;
+
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		hba->sdev_ufs_device = NULL;
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	}
+}
+
+/**
+ * ufshcd_task_req_compl - handle task management request completion
+ * @hba: per adapter instance
+ * @index: index of the completed request
+ * @resp: task management service response
+ *
+ * Returns non-zero value on error, zero on success
+ */
+static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index, u8 *resp)
+{
+	struct utp_task_req_desc *task_req_descp;
+	struct utp_upiu_task_rsp *task_rsp_upiup;
+	unsigned long flags;
+	int ocs_value;
+	int task_result;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+
+	/* Clear completed tasks from outstanding_tasks */
+	__clear_bit(index, &hba->outstanding_tasks);
+
+	task_req_descp = hba->utmrdl_base_addr;
+	ocs_value = ufshcd_get_tmr_ocs(&task_req_descp[index]);
+
+	if (ocs_value == OCS_SUCCESS) {
+		task_rsp_upiup = (struct utp_upiu_task_rsp *)
+				task_req_descp[index].task_rsp_upiu;
+		task_result = be32_to_cpu(task_rsp_upiup->header.dword_1);
+		task_result = ((task_result & MASK_TASK_RESPONSE) >> 8);
+		if (resp)
+			*resp = (u8)task_result;
+	} else {
+		dev_err(hba->dev, "%s: failed, ocs = 0x%x\n",
+				__func__, ocs_value);
+	}
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	return ocs_value;
+}
+
+/**
+ * ufshcd_scsi_cmd_status - Update SCSI command result based on SCSI status
+ * @lrb: pointer to local reference block of completed command
+ * @scsi_status: SCSI command status
+ *
+ * Returns value base on SCSI command status
+ */
+static inline int
+ufshcd_scsi_cmd_status(struct ufshcd_lrb *lrbp, int scsi_status)
+{
+	int result = 0;
+
+	switch (scsi_status) {
+	case SAM_STAT_CHECK_CONDITION:
+		ufshcd_copy_sense_data(lrbp);
+	case SAM_STAT_GOOD:
+		result |= DID_OK << 16 |
+			  COMMAND_COMPLETE << 8 |
+			  scsi_status;
+		break;
+	case SAM_STAT_TASK_SET_FULL:
+	case SAM_STAT_BUSY:
+	case SAM_STAT_TASK_ABORTED:
+		ufshcd_copy_sense_data(lrbp);
+		result |= scsi_status;
+		break;
+	default:
+		result |= DID_ERROR << 16;
+		break;
+	} /* end of switch */
+
+	return result;
+}
+
+/**
+ * ufshcd_transfer_rsp_status - Get overall status of the response
+ * @hba: per adapter instance
+ * @lrb: pointer to local reference block of completed command
+ *
+ * Returns result of the command to notify SCSI midlayer
+ */
+static inline int
+ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	int result = 0;
+	int scsi_status;
+	int ocs;
+
+	/* overall command status of utrd */
+	ocs = ufshcd_get_tr_ocs(lrbp);
+
+	switch (ocs) {
+	case OCS_SUCCESS:
+		result = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+		switch (result) {
+		case UPIU_TRANSACTION_RESPONSE:
+			/*
+			 * get the response UPIU result to extract
+			 * the SCSI command status
+			 */
+			result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
+
+			/*
+			 * get the result based on SCSI status response
+			 * to notify the SCSI midlayer of the command status
+			 */
+			scsi_status = result & MASK_SCSI_STATUS;
+			result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
+
+			if (ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
+				schedule_work(&hba->eeh_work);
+			break;
+		case UPIU_TRANSACTION_REJECT_UPIU:
+			/* TODO: handle Reject UPIU Response */
+			result = DID_ERROR << 16;
+			dev_err(hba->dev,
+				"Reject UPIU not fully implemented\n");
+			break;
+		default:
+			result = DID_ERROR << 16;
+			dev_err(hba->dev,
+				"Unexpected request response code = %x\n",
+				result);
+			break;
+		}
+		break;
+	case OCS_ABORTED:
+		result |= DID_ABORT << 16;
+		break;
+	case OCS_INVALID_COMMAND_STATUS:
+		result |= DID_REQUEUE << 16;
+		break;
+	case OCS_INVALID_CMD_TABLE_ATTR:
+	case OCS_INVALID_PRDT_ATTR:
+	case OCS_MISMATCH_DATA_BUF_SIZE:
+	case OCS_MISMATCH_RESP_UPIU_SIZE:
+	case OCS_PEER_COMM_FAILURE:
+	case OCS_FATAL_ERROR:
+	default:
+		result |= DID_ERROR << 16;
+		dev_err(hba->dev,
+		"OCS error from controller = %x\n", ocs);
+		break;
+	} /* end of switch */
+
+	return result;
+}
+
+/**
+ * ufshcd_uic_cmd_compl - handle completion of uic command
+ * @hba: per adapter instance
+ * @intr_status: interrupt status generated by the controller
+ */
+static void ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
+{
+	if ((intr_status & UIC_COMMAND_COMPL) && hba->active_uic_cmd) {
+		hba->active_uic_cmd->argument2 |=
+			ufshcd_get_uic_cmd_result(hba);
+		hba->active_uic_cmd->argument3 =
+			ufshcd_get_dme_attr_val(hba);
+		complete(&hba->active_uic_cmd->done);
+	}
+
+	if ((intr_status & UFSHCD_UIC_PWR_MASK) && hba->uic_async_done)
+		complete(hba->uic_async_done);
+}
+
+/**
+ * ufshcd_transfer_req_compl - handle SCSI and query command completion
+ * @hba: per adapter instance
+ */
+static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
+{
+	struct ufshcd_lrb *lrbp;
+	struct scsi_cmnd *cmd;
+	unsigned long completed_reqs;
+	u32 tr_doorbell;
+	int result;
+	int index;
+
+	/* Resetting interrupt aggregation counters first and reading the
+	 * DOOR_BELL afterward allows us to handle all the completed requests.
+	 * In order to prevent other interrupts starvation the DB is read once
+	 * after reset. The down side of this solution is the possibility of
+	 * false interrupt if device completes another request after resetting
+	 * aggregation and before reading the DB.
+	 */
+	ufshcd_reset_intr_aggr(hba);
+
+	tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
+	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
+
+	for_each_set_bit(index, &completed_reqs, hba->nutrs) {
+		lrbp = &hba->lrb[index];
+		cmd = lrbp->cmd;
+		if (cmd) {
+			result = ufshcd_transfer_rsp_status(hba, lrbp);
+			scsi_dma_unmap(cmd);
+			cmd->result = result;
+			/* Mark completed command as NULL in LRB */
+			lrbp->cmd = NULL;
+			clear_bit_unlock(index, &hba->lrb_in_use);
+			/* Do not touch lrbp after scsi done */
+			cmd->scsi_done(cmd);
+			__ufshcd_release(hba);
+		} else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE) {
+			if (hba->dev_cmd.complete)
+				complete(hba->dev_cmd.complete);
+		}
+	}
+
+	/* clear corresponding bits of completed commands */
+	hba->outstanding_reqs ^= completed_reqs;
+
+	ufshcd_clk_scaling_update_busy(hba);
+
+	/* we might have free'd some tags above */
+	wake_up(&hba->dev_cmd.tag_wq);
+}
+
+/**
+ * ufshcd_disable_ee - disable exception event
+ * @hba: per-adapter instance
+ * @mask: exception event to disable
+ *
+ * Disables exception event in the device so that the EVENT_ALERT
+ * bit is not set.
+ *
+ * Returns zero on success, non-zero error value on failure.
+ */
+static int ufshcd_disable_ee(struct ufs_hba *hba, u16 mask)
+{
+	int err = 0;
+	u32 val;
+
+	if (!(hba->ee_ctrl_mask & mask))
+		goto out;
+
+	val = hba->ee_ctrl_mask & ~mask;
+	val &= 0xFFFF; /* 2 bytes */
+	err = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+			QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &val);
+	if (!err)
+		hba->ee_ctrl_mask &= ~mask;
+out:
+	return err;
+}
+
+/**
+ * ufshcd_enable_ee - enable exception event
+ * @hba: per-adapter instance
+ * @mask: exception event to enable
+ *
+ * Enable corresponding exception event in the device to allow
+ * device to alert host in critical scenarios.
+ *
+ * Returns zero on success, non-zero error value on failure.
+ */
+static int ufshcd_enable_ee(struct ufs_hba *hba, u16 mask)
+{
+	int err = 0;
+	u32 val;
+
+	if (hba->ee_ctrl_mask & mask)
+		goto out;
+
+	val = hba->ee_ctrl_mask | mask;
+	val &= 0xFFFF; /* 2 bytes */
+	err = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+			QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &val);
+	if (!err)
+		hba->ee_ctrl_mask |= mask;
+out:
+	return err;
+}
+
+/**
+ * ufshcd_enable_auto_bkops - Allow device managed BKOPS
+ * @hba: per-adapter instance
+ *
+ * Allow device to manage background operations on its own. Enabling
+ * this might lead to inconsistent latencies during normal data transfers
+ * as the device is allowed to manage its own way of handling background
+ * operations.
+ *
+ * Returns zero on success, non-zero on failure.
+ */
+static int ufshcd_enable_auto_bkops(struct ufs_hba *hba)
+{
+	int err = 0;
+
+	if (hba->auto_bkops_enabled)
+		goto out;
+
+	err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_SET_FLAG,
+			QUERY_FLAG_IDN_BKOPS_EN, NULL);
+	if (err) {
+		dev_err(hba->dev, "%s: failed to enable bkops %d\n",
+				__func__, err);
+		goto out;
+	}
+
+	hba->auto_bkops_enabled = true;
+
+	/* No need of URGENT_BKOPS exception from the device */
+	err = ufshcd_disable_ee(hba, MASK_EE_URGENT_BKOPS);
+	if (err)
+		dev_err(hba->dev, "%s: failed to disable exception event %d\n",
+				__func__, err);
+out:
+	return err;
+}
+
+/**
+ * ufshcd_disable_auto_bkops - block device in doing background operations
+ * @hba: per-adapter instance
+ *
+ * Disabling background operations improves command response latency but
+ * has drawback of device moving into critical state where the device is
+ * not-operable. Make sure to call ufshcd_enable_auto_bkops() whenever the
+ * host is idle so that BKOPS are managed effectively without any negative
+ * impacts.
+ *
+ * Returns zero on success, non-zero on failure.
+ */
+static int ufshcd_disable_auto_bkops(struct ufs_hba *hba)
+{
+	int err = 0;
+
+	if (!hba->auto_bkops_enabled)
+		goto out;
+
+	/*
+	 * If host assisted BKOPs is to be enabled, make sure
+	 * urgent bkops exception is allowed.
+	 */
+	err = ufshcd_enable_ee(hba, MASK_EE_URGENT_BKOPS);
+	if (err) {
+		dev_err(hba->dev, "%s: failed to enable exception event %d\n",
+				__func__, err);
+		goto out;
+	}
+
+	err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_CLEAR_FLAG,
+			QUERY_FLAG_IDN_BKOPS_EN, NULL);
+	if (err) {
+		dev_err(hba->dev, "%s: failed to disable bkops %d\n",
+				__func__, err);
+		ufshcd_disable_ee(hba, MASK_EE_URGENT_BKOPS);
+		goto out;
+	}
+
+	hba->auto_bkops_enabled = false;
+out:
+	return err;
+}
+
+/**
+ * ufshcd_force_reset_auto_bkops - force enable of auto bkops
+ * @hba: per adapter instance
+ *
+ * After a device reset the device may toggle the BKOPS_EN flag
+ * to default value. The s/w tracking variables should be updated
+ * as well. Do this by forcing enable of auto bkops.
+ */
+static void  ufshcd_force_reset_auto_bkops(struct ufs_hba *hba)
+{
+	hba->auto_bkops_enabled = false;
+	hba->ee_ctrl_mask |= MASK_EE_URGENT_BKOPS;
+	ufshcd_enable_auto_bkops(hba);
+}
+
+static inline int ufshcd_get_bkops_status(struct ufs_hba *hba, u32 *status)
+{
+	return ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+			QUERY_ATTR_IDN_BKOPS_STATUS, 0, 0, status);
+}
+
+/**
+ * ufshcd_bkops_ctrl - control the auto bkops based on current bkops status
+ * @hba: per-adapter instance
+ * @status: bkops_status value
+ *
+ * Read the bkops_status from the UFS device and Enable fBackgroundOpsEn
+ * flag in the device to permit background operations if the device
+ * bkops_status is greater than or equal to "status" argument passed to
+ * this function, disable otherwise.
+ *
+ * Returns 0 for success, non-zero in case of failure.
+ *
+ * NOTE: Caller of this function can check the "hba->auto_bkops_enabled" flag
+ * to know whether auto bkops is enabled or disabled after this function
+ * returns control to it.
+ */
+static int ufshcd_bkops_ctrl(struct ufs_hba *hba,
+			     enum bkops_status status)
+{
+	int err;
+	u32 curr_status = 0;
+
+	err = ufshcd_get_bkops_status(hba, &curr_status);
+	if (err) {
+		dev_err(hba->dev, "%s: failed to get BKOPS status %d\n",
+				__func__, err);
+		goto out;
+	} else if (curr_status > BKOPS_STATUS_MAX) {
+		dev_err(hba->dev, "%s: invalid BKOPS status %d\n",
+				__func__, curr_status);
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (curr_status >= status)
+		err = ufshcd_enable_auto_bkops(hba);
+	else
+		err = ufshcd_disable_auto_bkops(hba);
+out:
+	return err;
+}
+
+/**
+ * ufshcd_urgent_bkops - handle urgent bkops exception event
+ * @hba: per-adapter instance
+ *
+ * Enable fBackgroundOpsEn flag in the device to permit background
+ * operations.
+ *
+ * If BKOPs is enabled, this function returns 0, 1 if the bkops in not enabled
+ * and negative error value for any other failure.
+ */
+static int ufshcd_urgent_bkops(struct ufs_hba *hba)
+{
+	return ufshcd_bkops_ctrl(hba, BKOPS_STATUS_PERF_IMPACT);
+}
+
+static inline int ufshcd_get_ee_status(struct ufs_hba *hba, u32 *status)
+{
+	return ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+			QUERY_ATTR_IDN_EE_STATUS, 0, 0, status);
+}
+
+/**
+ * ufshcd_exception_event_handler - handle exceptions raised by device
+ * @work: pointer to work data
+ *
+ * Read bExceptionEventStatus attribute from the device and handle the
+ * exception event accordingly.
+ */
+static void ufshcd_exception_event_handler(struct work_struct *work)
+{
+	struct ufs_hba *hba;
+	int err;
+	u32 status = 0;
+	hba = container_of(work, struct ufs_hba, eeh_work);
+
+	pm_runtime_get_sync(hba->dev);
+	err = ufshcd_get_ee_status(hba, &status);
+	if (err) {
+		dev_err(hba->dev, "%s: failed to get exception status %d\n",
+				__func__, err);
+		goto out;
+	}
+
+	status &= hba->ee_ctrl_mask;
+	if (status & MASK_EE_URGENT_BKOPS) {
+		err = ufshcd_urgent_bkops(hba);
+		if (err < 0)
+			dev_err(hba->dev, "%s: failed to handle urgent bkops %d\n",
+					__func__, err);
+	}
+out:
+	pm_runtime_put_sync(hba->dev);
+	return;
+}
+
+/**
+ * ufshcd_err_handler - handle UFS errors that require s/w attention
+ * @work: pointer to work structure
+ */
+static void ufshcd_err_handler(struct work_struct *work)
+{
+	struct ufs_hba *hba;
+	unsigned long flags;
+	u32 err_xfer = 0;
+	u32 err_tm = 0;
+	int err = 0;
+	int tag;
+
+	hba = container_of(work, struct ufs_hba, eh_work);
+
+	pm_runtime_get_sync(hba->dev);
+	ufshcd_hold(hba, false);
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (hba->ufshcd_state == UFSHCD_STATE_RESET) {
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+		goto out;
+	}
+
+	hba->ufshcd_state = UFSHCD_STATE_RESET;
+	ufshcd_set_eh_in_progress(hba);
+
+	/* Complete requests that have door-bell cleared by h/w */
+	ufshcd_transfer_req_compl(hba);
+	ufshcd_tmc_handler(hba);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/* Clear pending transfer requests */
+	for_each_set_bit(tag, &hba->outstanding_reqs, hba->nutrs)
+		if (ufshcd_clear_cmd(hba, tag))
+			err_xfer |= 1 << tag;
+
+	/* Clear pending task management requests */
+	for_each_set_bit(tag, &hba->outstanding_tasks, hba->nutmrs)
+		if (ufshcd_clear_tm_cmd(hba, tag))
+			err_tm |= 1 << tag;
+
+	/* Complete the requests that are cleared by s/w */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_transfer_req_compl(hba);
+	ufshcd_tmc_handler(hba);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/* Fatal errors need reset */
+	if (err_xfer || err_tm || (hba->saved_err & INT_FATAL_ERRORS) ||
+			((hba->saved_err & UIC_ERROR) &&
+			 (hba->saved_uic_err & UFSHCD_UIC_DL_PA_INIT_ERROR))) {
+		err = ufshcd_reset_and_restore(hba);
+		if (err) {
+			dev_err(hba->dev, "%s: reset and restore failed\n",
+					__func__);
+			hba->ufshcd_state = UFSHCD_STATE_ERROR;
+		}
+		/*
+		 * Inform scsi mid-layer that we did reset and allow to handle
+		 * Unit Attention properly.
+		 */
+		scsi_report_bus_reset(hba->host, 0);
+		hba->saved_err = 0;
+		hba->saved_uic_err = 0;
+	}
+	ufshcd_clear_eh_in_progress(hba);
+
+out:
+	scsi_unblock_requests(hba->host);
+	ufshcd_release(hba);
+	pm_runtime_put_sync(hba->dev);
+}
+
+/**
+ * ufshcd_update_uic_error - check and set fatal UIC error flags.
+ * @hba: per-adapter instance
+ */
+static void ufshcd_update_uic_error(struct ufs_hba *hba)
+{
+	u32 reg;
+
+	/* PA_INIT_ERROR is fatal and needs UIC reset */
+	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DATA_LINK_LAYER);
+	if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
+		hba->uic_error |= UFSHCD_UIC_DL_PA_INIT_ERROR;
+
+	/* UIC NL/TL/DME errors needs software retry */
+	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_NETWORK_LAYER);
+	if (reg)
+		hba->uic_error |= UFSHCD_UIC_NL_ERROR;
+
+	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_TRANSPORT_LAYER);
+	if (reg)
+		hba->uic_error |= UFSHCD_UIC_TL_ERROR;
+
+	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DME);
+	if (reg)
+		hba->uic_error |= UFSHCD_UIC_DME_ERROR;
+
+	dev_dbg(hba->dev, "%s: UIC error flags = 0x%08x\n",
+			__func__, hba->uic_error);
+}
+
+/**
+ * ufshcd_check_errors - Check for errors that need s/w attention
+ * @hba: per-adapter instance
+ */
+static void ufshcd_check_errors(struct ufs_hba *hba)
+{
+	bool queue_eh_work = false;
+
+	if (hba->errors & INT_FATAL_ERRORS)
+		queue_eh_work = true;
+
+	if (hba->errors & UIC_ERROR) {
+		hba->uic_error = 0;
+		ufshcd_update_uic_error(hba);
+		if (hba->uic_error)
+			queue_eh_work = true;
+	}
+
+	if (queue_eh_work) {
+		/* handle fatal errors only when link is functional */
+		if (hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL) {
+			/* block commands from scsi mid-layer */
+			scsi_block_requests(hba->host);
+
+			/* transfer error masks to sticky bits */
+			hba->saved_err |= hba->errors;
+			hba->saved_uic_err |= hba->uic_error;
+
+			hba->ufshcd_state = UFSHCD_STATE_ERROR;
+			schedule_work(&hba->eh_work);
+		}
+	}
+	/*
+	 * if (!queue_eh_work) -
+	 * Other errors are either non-fatal where host recovers
+	 * itself without s/w intervention or errors that will be
+	 * handled by the SCSI core layer.
+	 */
+}
+
+/**
+ * ufshcd_tmc_handler - handle task management function completion
+ * @hba: per adapter instance
+ */
+static void ufshcd_tmc_handler(struct ufs_hba *hba)
+{
+	u32 tm_doorbell;
+
+	tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
+	hba->tm_condition = tm_doorbell ^ hba->outstanding_tasks;
+	wake_up(&hba->tm_wq);
+}
+
+/**
+ * ufshcd_sl_intr - Interrupt service routine
+ * @hba: per adapter instance
+ * @intr_status: contains interrupts generated by the controller
+ */
+static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
+{
+	hba->errors = UFSHCD_ERROR_MASK & intr_status;
+	if (hba->errors)
+		ufshcd_check_errors(hba);
+
+	if (intr_status & UFSHCD_UIC_MASK)
+		ufshcd_uic_cmd_compl(hba, intr_status);
+
+	if (intr_status & UTP_TASK_REQ_COMPL)
+		ufshcd_tmc_handler(hba);
+
+	if (intr_status & UTP_TRANSFER_REQ_COMPL)
+		ufshcd_transfer_req_compl(hba);
+}
+
+/**
+ * ufshcd_intr - Main interrupt service routine
+ * @irq: irq number
+ * @__hba: pointer to adapter instance
+ *
+ * Returns IRQ_HANDLED - If interrupt is valid
+ *		IRQ_NONE - If invalid interrupt
+ */
+static irqreturn_t ufshcd_intr(int irq, void *__hba)
+{
+	u32 intr_status;
+	irqreturn_t retval = IRQ_NONE;
+	struct ufs_hba *hba = __hba;
+
+	spin_lock(hba->host->host_lock);
+	intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
+
+	if (intr_status) {
+		ufshcd_writel(hba, intr_status, REG_INTERRUPT_STATUS);
+		ufshcd_sl_intr(hba, intr_status);
+		retval = IRQ_HANDLED;
+	}
+	spin_unlock(hba->host->host_lock);
+	return retval;
+}
+
+static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag)
+{
+	int err = 0;
+	u32 mask = 1 << tag;
+	unsigned long flags;
+
+	if (!test_bit(tag, &hba->outstanding_tasks))
+		goto out;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_writel(hba, ~(1 << tag), REG_UTP_TASK_REQ_LIST_CLEAR);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/* poll for max. 1 sec to clear door bell register by h/w */
+	err = ufshcd_wait_for_register(hba,
+			REG_UTP_TASK_REQ_DOOR_BELL,
+			mask, 0, 1000, 1000);
+out:
+	return err;
+}
+
+/**
+ * ufshcd_issue_tm_cmd - issues task management commands to controller
+ * @hba: per adapter instance
+ * @lun_id: LUN ID to which TM command is sent
+ * @task_id: task ID to which the TM command is applicable
+ * @tm_function: task management function opcode
+ * @tm_response: task management service response return value
+ *
+ * Returns non-zero value on error, zero on success.
+ */
+static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int lun_id, int task_id,
+		u8 tm_function, u8 *tm_response)
+{
+	struct utp_task_req_desc *task_req_descp;
+	struct utp_upiu_task_req *task_req_upiup;
+	struct Scsi_Host *host;
+	unsigned long flags;
+	int free_slot;
+	int err;
+	int task_tag;
+
+	host = hba->host;
+
+	/*
+	 * Get free slot, sleep if slots are unavailable.
+	 * Even though we use wait_event() which sleeps indefinitely,
+	 * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
+	 */
+	wait_event(hba->tm_tag_wq, ufshcd_get_tm_free_slot(hba, &free_slot));
+	ufshcd_hold(hba, false);
+
+	spin_lock_irqsave(host->host_lock, flags);
+	task_req_descp = hba->utmrdl_base_addr;
+	task_req_descp += free_slot;
+
+	/* Configure task request descriptor */
+	task_req_descp->header.dword_0 = cpu_to_le32(UTP_REQ_DESC_INT_CMD);
+	task_req_descp->header.dword_2 =
+			cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
+
+	/* Configure task request UPIU */
+	task_req_upiup =
+		(struct utp_upiu_task_req *) task_req_descp->task_req_upiu;
+	task_tag = hba->nutrs + free_slot;
+	task_req_upiup->header.dword_0 =
+		UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
+					      lun_id, task_tag);
+	task_req_upiup->header.dword_1 =
+		UPIU_HEADER_DWORD(0, tm_function, 0, 0);
+	/*
+	 * The host shall provide the same value for LUN field in the basic
+	 * header and for Input Parameter.
+	 */
+	task_req_upiup->input_param1 = cpu_to_be32(lun_id);
+	task_req_upiup->input_param2 = cpu_to_be32(task_id);
+
+	/* send command to the controller */
+	__set_bit(free_slot, &hba->outstanding_tasks);
+	ufshcd_writel(hba, 1 << free_slot, REG_UTP_TASK_REQ_DOOR_BELL);
+
+	spin_unlock_irqrestore(host->host_lock, flags);
+
+	/* wait until the task management command is completed */
+	err = wait_event_timeout(hba->tm_wq,
+			test_bit(free_slot, &hba->tm_condition),
+			msecs_to_jiffies(TM_CMD_TIMEOUT));
+	if (!err) {
+		dev_err(hba->dev, "%s: task management cmd 0x%.2x timed-out\n",
+				__func__, tm_function);
+		if (ufshcd_clear_tm_cmd(hba, free_slot))
+			dev_WARN(hba->dev, "%s: unable clear tm cmd (slot %d) after timeout\n",
+					__func__, free_slot);
+		err = -ETIMEDOUT;
+	} else {
+		err = ufshcd_task_req_compl(hba, free_slot, tm_response);
+	}
+
+	clear_bit(free_slot, &hba->tm_condition);
+	ufshcd_put_tm_slot(hba, free_slot);
+	wake_up(&hba->tm_tag_wq);
+
+	ufshcd_release(hba);
+	return err;
+}
+
+/**
+ * ufshcd_eh_device_reset_handler - device reset handler registered to
+ *                                    scsi layer.
+ * @cmd: SCSI command pointer
+ *
+ * Returns SUCCESS/FAILED
+ */
+static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd)
+{
+	struct Scsi_Host *host;
+	struct ufs_hba *hba;
+	unsigned int tag;
+	u32 pos;
+	int err;
+	u8 resp = 0xF;
+	struct ufshcd_lrb *lrbp;
+	unsigned long flags;
+
+	host = cmd->device->host;
+	hba = shost_priv(host);
+	tag = cmd->request->tag;
+
+	lrbp = &hba->lrb[tag];
+	err = ufshcd_issue_tm_cmd(hba, lrbp->lun, 0, UFS_LOGICAL_RESET, &resp);
+	if (err || resp != UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
+		if (!err)
+			err = resp;
+		goto out;
+	}
+
+	/* clear the commands that were pending for corresponding LUN */
+	for_each_set_bit(pos, &hba->outstanding_reqs, hba->nutrs) {
+		if (hba->lrb[pos].lun == lrbp->lun) {
+			err = ufshcd_clear_cmd(hba, pos);
+			if (err)
+				break;
+		}
+	}
+	spin_lock_irqsave(host->host_lock, flags);
+	ufshcd_transfer_req_compl(hba);
+	spin_unlock_irqrestore(host->host_lock, flags);
+out:
+	if (!err) {
+		err = SUCCESS;
+	} else {
+		dev_err(hba->dev, "%s: failed with err %d\n", __func__, err);
+		err = FAILED;
+	}
+	return err;
+}
+
+/**
+ * ufshcd_abort - abort a specific command
+ * @cmd: SCSI command pointer
+ *
+ * Abort the pending command in device by sending UFS_ABORT_TASK task management
+ * command, and in host controller by clearing the door-bell register. There can
+ * be race between controller sending the command to the device while abort is
+ * issued. To avoid that, first issue UFS_QUERY_TASK to check if the command is
+ * really issued and then try to abort it.
+ *
+ * Returns SUCCESS/FAILED
+ */
+static int ufshcd_abort(struct scsi_cmnd *cmd)
+{
+	struct Scsi_Host *host;
+	struct ufs_hba *hba;
+	unsigned long flags;
+	unsigned int tag;
+	int err = 0;
+	int poll_cnt;
+	u8 resp = 0xF;
+	struct ufshcd_lrb *lrbp;
+	u32 reg;
+
+	host = cmd->device->host;
+	hba = shost_priv(host);
+	tag = cmd->request->tag;
+
+	ufshcd_hold(hba, false);
+	/* If command is already aborted/completed, return SUCCESS */
+	if (!(test_bit(tag, &hba->outstanding_reqs)))
+		goto out;
+
+	reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
+	if (!(reg & (1 << tag))) {
+		dev_err(hba->dev,
+		"%s: cmd was completed, but without a notifying intr, tag = %d",
+		__func__, tag);
+	}
+
+	lrbp = &hba->lrb[tag];
+	for (poll_cnt = 100; poll_cnt; poll_cnt--) {
+		err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
+				UFS_QUERY_TASK, &resp);
+		if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_SUCCEEDED) {
+			/* cmd pending in the device */
+			break;
+		} else if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
+			/*
+			 * cmd not pending in the device, check if it is
+			 * in transition.
+			 */
+			reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
+			if (reg & (1 << tag)) {
+				/* sleep for max. 200us to stabilize */
+				usleep_range(100, 200);
+				continue;
+			}
+			/* command completed already */
+			goto out;
+		} else {
+			if (!err)
+				err = resp; /* service response error */
+			goto out;
+		}
+	}
+
+	if (!poll_cnt) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
+			UFS_ABORT_TASK, &resp);
+	if (err || resp != UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
+		if (!err)
+			err = resp; /* service response error */
+		goto out;
+	}
+
+	err = ufshcd_clear_cmd(hba, tag);
+	if (err)
+		goto out;
+
+	scsi_dma_unmap(cmd);
+
+	spin_lock_irqsave(host->host_lock, flags);
+	__clear_bit(tag, &hba->outstanding_reqs);
+	hba->lrb[tag].cmd = NULL;
+	spin_unlock_irqrestore(host->host_lock, flags);
+
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+	wake_up(&hba->dev_cmd.tag_wq);
+
+out:
+	if (!err) {
+		err = SUCCESS;
+	} else {
+		dev_err(hba->dev, "%s: failed with err %d\n", __func__, err);
+		err = FAILED;
+	}
+
+	/*
+	 * This ufshcd_release() corresponds to the original scsi cmd that got
+	 * aborted here (as we won't get any IRQ for it).
+	 */
+	ufshcd_release(hba);
+	return err;
+}
+
+/**
+ * ufshcd_host_reset_and_restore - reset and restore host controller
+ * @hba: per-adapter instance
+ *
+ * Note that host controller reset may issue DME_RESET to
+ * local and remote (device) Uni-Pro stack and the attributes
+ * are reset to default state.
+ *
+ * Returns zero on success, non-zero on failure
+ */
+static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
+{
+	int err;
+	unsigned long flags;
+
+	/* Reset the host controller */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_hba_stop(hba);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	err = ufshcd_hba_enable(hba);
+	if (err)
+		goto out;
+
+	/* Establish the link again and restore the device */
+	err = ufshcd_probe_hba(hba);
+
+	if (!err && (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL))
+		err = -EIO;
+out:
+	if (err)
+		dev_err(hba->dev, "%s: Host init failed %d\n", __func__, err);
+
+	return err;
+}
+
+/**
+ * ufshcd_reset_and_restore - reset and re-initialize host/device
+ * @hba: per-adapter instance
+ *
+ * Reset and recover device, host and re-establish link. This
+ * is helpful to recover the communication in fatal error conditions.
+ *
+ * Returns zero on success, non-zero on failure
+ */
+static int ufshcd_reset_and_restore(struct ufs_hba *hba)
+{
+	int err = 0;
+	unsigned long flags;
+	int retries = MAX_HOST_RESET_RETRIES;
+
+	do {
+		err = ufshcd_host_reset_and_restore(hba);
+	} while (err && --retries);
+
+	/*
+	 * After reset the door-bell might be cleared, complete
+	 * outstanding requests in s/w here.
+	 */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_transfer_req_compl(hba);
+	ufshcd_tmc_handler(hba);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	return err;
+}
+
+/**
+ * ufshcd_eh_host_reset_handler - host reset handler registered to scsi layer
+ * @cmd - SCSI command pointer
+ *
+ * Returns SUCCESS/FAILED
+ */
+static int ufshcd_eh_host_reset_handler(struct scsi_cmnd *cmd)
+{
+	int err;
+	unsigned long flags;
+	struct ufs_hba *hba;
+
+	hba = shost_priv(cmd->device->host);
+
+	ufshcd_hold(hba, false);
+	/*
+	 * Check if there is any race with fatal error handling.
+	 * If so, wait for it to complete. Even though fatal error
+	 * handling does reset and restore in some cases, don't assume
+	 * anything out of it. We are just avoiding race here.
+	 */
+	do {
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		if (!(work_pending(&hba->eh_work) ||
+				hba->ufshcd_state == UFSHCD_STATE_RESET))
+			break;
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+		dev_dbg(hba->dev, "%s: reset in progress\n", __func__);
+		flush_work(&hba->eh_work);
+	} while (1);
+
+	hba->ufshcd_state = UFSHCD_STATE_RESET;
+	ufshcd_set_eh_in_progress(hba);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	err = ufshcd_reset_and_restore(hba);
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (!err) {
+		err = SUCCESS;
+		hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
+	} else {
+		err = FAILED;
+		hba->ufshcd_state = UFSHCD_STATE_ERROR;
+	}
+	ufshcd_clear_eh_in_progress(hba);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	ufshcd_release(hba);
+	return err;
+}
+
+/**
+ * ufshcd_get_max_icc_level - calculate the ICC level
+ * @sup_curr_uA: max. current supported by the regulator
+ * @start_scan: row at the desc table to start scan from
+ * @buff: power descriptor buffer
+ *
+ * Returns calculated max ICC level for specific regulator
+ */
+static u32 ufshcd_get_max_icc_level(int sup_curr_uA, u32 start_scan, char *buff)
+{
+	int i;
+	int curr_uA;
+	u16 data;
+	u16 unit;
+
+	for (i = start_scan; i >= 0; i--) {
+		data = be16_to_cpu(*((u16 *)(buff + 2*i)));
+		unit = (data & ATTR_ICC_LVL_UNIT_MASK) >>
+						ATTR_ICC_LVL_UNIT_OFFSET;
+		curr_uA = data & ATTR_ICC_LVL_VALUE_MASK;
+		switch (unit) {
+		case UFSHCD_NANO_AMP:
+			curr_uA = curr_uA / 1000;
+			break;
+		case UFSHCD_MILI_AMP:
+			curr_uA = curr_uA * 1000;
+			break;
+		case UFSHCD_AMP:
+			curr_uA = curr_uA * 1000 * 1000;
+			break;
+		case UFSHCD_MICRO_AMP:
+		default:
+			break;
+		}
+		if (sup_curr_uA >= curr_uA)
+			break;
+	}
+	if (i < 0) {
+		i = 0;
+		pr_err("%s: Couldn't find valid icc_level = %d", __func__, i);
+	}
+
+	return (u32)i;
+}
+
+/**
+ * ufshcd_calc_icc_level - calculate the max ICC level
+ * In case regulators are not initialized we'll return 0
+ * @hba: per-adapter instance
+ * @desc_buf: power descriptor buffer to extract ICC levels from.
+ * @len: length of desc_buff
+ *
+ * Returns calculated ICC level
+ */
+static u32 ufshcd_find_max_sup_active_icc_level(struct ufs_hba *hba,
+							u8 *desc_buf, int len)
+{
+	u32 icc_level = 0;
+
+	if (!hba->vreg_info.vcc || !hba->vreg_info.vccq ||
+						!hba->vreg_info.vccq2) {
+		dev_err(hba->dev,
+			"%s: Regulator capability was not set, actvIccLevel=%d",
+							__func__, icc_level);
+		goto out;
+	}
+
+	if (hba->vreg_info.vcc)
+		icc_level = ufshcd_get_max_icc_level(
+				hba->vreg_info.vcc->max_uA,
+				POWER_DESC_MAX_ACTV_ICC_LVLS - 1,
+				&desc_buf[PWR_DESC_ACTIVE_LVLS_VCC_0]);
+
+	if (hba->vreg_info.vccq)
+		icc_level = ufshcd_get_max_icc_level(
+				hba->vreg_info.vccq->max_uA,
+				icc_level,
+				&desc_buf[PWR_DESC_ACTIVE_LVLS_VCCQ_0]);
+
+	if (hba->vreg_info.vccq2)
+		icc_level = ufshcd_get_max_icc_level(
+				hba->vreg_info.vccq2->max_uA,
+				icc_level,
+				&desc_buf[PWR_DESC_ACTIVE_LVLS_VCCQ2_0]);
+out:
+	return icc_level;
+}
+
+static void ufshcd_init_icc_levels(struct ufs_hba *hba)
+{
+	int ret;
+	int buff_len = QUERY_DESC_POWER_MAX_SIZE;
+	u8 desc_buf[QUERY_DESC_POWER_MAX_SIZE];
+
+	ret = ufshcd_read_power_desc(hba, desc_buf, buff_len);
+	if (ret) {
+		dev_err(hba->dev,
+			"%s: Failed reading power descriptor.len = %d ret = %d",
+			__func__, buff_len, ret);
+		return;
+	}
+
+	hba->init_prefetch_data.icc_level =
+			ufshcd_find_max_sup_active_icc_level(hba,
+			desc_buf, buff_len);
+	dev_dbg(hba->dev, "%s: setting icc_level 0x%x",
+			__func__, hba->init_prefetch_data.icc_level);
+
+	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+			QUERY_ATTR_IDN_ACTIVE_ICC_LVL, 0, 0,
+			&hba->init_prefetch_data.icc_level);
+
+	if (ret)
+		dev_err(hba->dev,
+			"%s: Failed configuring bActiveICCLevel = %d ret = %d",
+			__func__, hba->init_prefetch_data.icc_level , ret);
+
+}
+
+/**
+ * ufshcd_scsi_add_wlus - Adds required W-LUs
+ * @hba: per-adapter instance
+ *
+ * UFS device specification requires the UFS devices to support 4 well known
+ * logical units:
+ *	"REPORT_LUNS" (address: 01h)
+ *	"UFS Device" (address: 50h)
+ *	"RPMB" (address: 44h)
+ *	"BOOT" (address: 30h)
+ * UFS device's power management needs to be controlled by "POWER CONDITION"
+ * field of SSU (START STOP UNIT) command. But this "power condition" field
+ * will take effect only when its sent to "UFS device" well known logical unit
+ * hence we require the scsi_device instance to represent this logical unit in
+ * order for the UFS host driver to send the SSU command for power management.
+
+ * We also require the scsi_device instance for "RPMB" (Replay Protected Memory
+ * Block) LU so user space process can control this LU. User space may also
+ * want to have access to BOOT LU.
+
+ * This function adds scsi device instances for each of all well known LUs
+ * (except "REPORT LUNS" LU).
+ *
+ * Returns zero on success (all required W-LUs are added successfully),
+ * non-zero error value on failure (if failed to add any of the required W-LU).
+ */
+static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
+{
+	int ret = 0;
+	struct scsi_device *sdev_rpmb;
+	struct scsi_device *sdev_boot;
+
+	hba->sdev_ufs_device = __scsi_add_device(hba->host, 0, 0,
+		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN), NULL);
+	if (IS_ERR(hba->sdev_ufs_device)) {
+		ret = PTR_ERR(hba->sdev_ufs_device);
+		hba->sdev_ufs_device = NULL;
+		goto out;
+	}
+	scsi_device_put(hba->sdev_ufs_device);
+
+	sdev_boot = __scsi_add_device(hba->host, 0, 0,
+		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_BOOT_WLUN), NULL);
+	if (IS_ERR(sdev_boot)) {
+		ret = PTR_ERR(sdev_boot);
+		goto remove_sdev_ufs_device;
+	}
+	scsi_device_put(sdev_boot);
+
+	sdev_rpmb = __scsi_add_device(hba->host, 0, 0,
+		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN), NULL);
+	if (IS_ERR(sdev_rpmb)) {
+		ret = PTR_ERR(sdev_rpmb);
+		goto remove_sdev_boot;
+	}
+	scsi_device_put(sdev_rpmb);
+	goto out;
+
+remove_sdev_boot:
+	scsi_remove_device(sdev_boot);
+remove_sdev_ufs_device:
+	scsi_remove_device(hba->sdev_ufs_device);
+out:
+	return ret;
+}
+
+/**
+ * ufshcd_probe_hba - probe hba to detect device and initialize
+ * @hba: per-adapter instance
+ *
+ * Execute link-startup and verify device initialization
+ */
+static int ufshcd_probe_hba(struct ufs_hba *hba)
+{
+	int ret;
+
+	ret = ufshcd_link_startup(hba);
+	if (ret)
+		goto out;
+
+	ufshcd_init_pwr_info(hba);
+
+	/* UniPro link is active now */
+	ufshcd_set_link_active(hba);
+
+	ret = ufshcd_verify_dev_init(hba);
+	if (ret)
+		goto out;
+
+	ret = ufshcd_complete_dev_init(hba);
+	if (ret)
+		goto out;
+
+	/* UFS device is also active now */
+	ufshcd_set_ufs_dev_active(hba);
+	ufshcd_force_reset_auto_bkops(hba);
+	hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
+	hba->wlun_dev_clr_ua = true;
+
+	if (ufshcd_get_max_pwr_mode(hba)) {
+		dev_err(hba->dev,
+			"%s: Failed getting max supported power mode\n",
+			__func__);
+	} else {
+		ret = ufshcd_config_pwr_mode(hba, &hba->max_pwr_info.info);
+		if (ret)
+			dev_err(hba->dev, "%s: Failed setting power mode, err = %d\n",
+					__func__, ret);
+	}
+
+	/*
+	 * If we are in error handling context or in power management callbacks
+	 * context, no need to scan the host
+	 */
+	if (!ufshcd_eh_in_progress(hba) && !hba->pm_op_in_progress) {
+		bool flag;
+
+		/* clear any previous UFS device information */
+		memset(&hba->dev_info, 0, sizeof(hba->dev_info));
+		if (!ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG,
+				       QUERY_FLAG_IDN_PWR_ON_WPE, &flag))
+			hba->dev_info.f_power_on_wp_en = flag;
+
+		if (!hba->is_init_prefetch)
+			ufshcd_init_icc_levels(hba);
+
+		/* Add required well known logical units to scsi mid layer */
+		if (ufshcd_scsi_add_wlus(hba))
+			goto out;
+
+		scsi_scan_host(hba->host);
+		pm_runtime_put_sync(hba->dev);
+	}
+
+	if (!hba->is_init_prefetch)
+		hba->is_init_prefetch = true;
+
+	/* Resume devfreq after UFS device is detected */
+	if (ufshcd_is_clkscaling_enabled(hba))
+		devfreq_resume_device(hba->devfreq);
+
+out:
+	/*
+	 * If we failed to initialize the device or the device is not
+	 * present, turn off the power/clocks etc.
+	 */
+	if (ret && !ufshcd_eh_in_progress(hba) && !hba->pm_op_in_progress) {
+		pm_runtime_put_sync(hba->dev);
+		ufshcd_hba_exit(hba);
+	}
+
+	return ret;
+}
+
+/**
+ * ufshcd_async_scan - asynchronous execution for probing hba
+ * @data: data pointer to pass to this function
+ * @cookie: cookie data
+ */
+static void ufshcd_async_scan(void *data, async_cookie_t cookie)
+{
+	struct ufs_hba *hba = (struct ufs_hba *)data;
+
+	ufshcd_probe_hba(hba);
+}
+
+static struct scsi_host_template ufshcd_driver_template = {
+	.module			= THIS_MODULE,
+	.name			= UFSHCD,
+	.proc_name		= UFSHCD,
+	.queuecommand		= ufshcd_queuecommand,
+	.slave_alloc		= ufshcd_slave_alloc,
+	.slave_configure	= ufshcd_slave_configure,
+	.slave_destroy		= ufshcd_slave_destroy,
+	.change_queue_depth	= ufshcd_change_queue_depth,
+	.eh_abort_handler	= ufshcd_abort,
+	.eh_device_reset_handler = ufshcd_eh_device_reset_handler,
+	.eh_host_reset_handler   = ufshcd_eh_host_reset_handler,
+	.this_id		= -1,
+	.sg_tablesize		= SG_ALL,
+	.cmd_per_lun		= UFSHCD_CMD_PER_LUN,
+	.can_queue		= UFSHCD_CAN_QUEUE,
+	.max_host_blocked	= 1,
+	.use_blk_tags		= 1,
+	.track_queue_depth	= 1,
+};
+
+static int ufshcd_config_vreg_load(struct device *dev, struct ufs_vreg *vreg,
+				   int ua)
+{
+	int ret;
+
+	if (!vreg)
+		return 0;
+
+	ret = regulator_set_load(vreg->reg, ua);
+	if (ret < 0) {
+		dev_err(dev, "%s: %s set load (ua=%d) failed, err=%d\n",
+				__func__, vreg->name, ua, ret);
+	}
+
+	return ret;
+}
+
+static inline int ufshcd_config_vreg_lpm(struct ufs_hba *hba,
+					 struct ufs_vreg *vreg)
+{
+	return ufshcd_config_vreg_load(hba->dev, vreg, UFS_VREG_LPM_LOAD_UA);
+}
+
+static inline int ufshcd_config_vreg_hpm(struct ufs_hba *hba,
+					 struct ufs_vreg *vreg)
+{
+	return ufshcd_config_vreg_load(hba->dev, vreg, vreg->max_uA);
+}
+
+static int ufshcd_config_vreg(struct device *dev,
+		struct ufs_vreg *vreg, bool on)
+{
+	int ret = 0;
+	struct regulator *reg = vreg->reg;
+	const char *name = vreg->name;
+	int min_uV, uA_load;
+
+	BUG_ON(!vreg);
+
+	if (regulator_count_voltages(reg) > 0) {
+		min_uV = on ? vreg->min_uV : 0;
+		ret = regulator_set_voltage(reg, min_uV, vreg->max_uV);
+		if (ret) {
+			dev_err(dev, "%s: %s set voltage failed, err=%d\n",
+					__func__, name, ret);
+			goto out;
+		}
+
+		uA_load = on ? vreg->max_uA : 0;
+		ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
+		if (ret)
+			goto out;
+	}
+out:
+	return ret;
+}
+
+static int ufshcd_enable_vreg(struct device *dev, struct ufs_vreg *vreg)
+{
+	int ret = 0;
+
+	if (!vreg || vreg->enabled)
+		goto out;
+
+	ret = ufshcd_config_vreg(dev, vreg, true);
+	if (!ret)
+		ret = regulator_enable(vreg->reg);
+
+	if (!ret)
+		vreg->enabled = true;
+	else
+		dev_err(dev, "%s: %s enable failed, err=%d\n",
+				__func__, vreg->name, ret);
+out:
+	return ret;
+}
+
+static int ufshcd_disable_vreg(struct device *dev, struct ufs_vreg *vreg)
+{
+	int ret = 0;
+
+	if (!vreg || !vreg->enabled)
+		goto out;
+
+	ret = regulator_disable(vreg->reg);
+
+	if (!ret) {
+		/* ignore errors on applying disable config */
+		ufshcd_config_vreg(dev, vreg, false);
+		vreg->enabled = false;
+	} else {
+		dev_err(dev, "%s: %s disable failed, err=%d\n",
+				__func__, vreg->name, ret);
+	}
+out:
+	return ret;
+}
+
+static int ufshcd_setup_vreg(struct ufs_hba *hba, bool on)
+{
+	int ret = 0;
+	struct device *dev = hba->dev;
+	struct ufs_vreg_info *info = &hba->vreg_info;
+
+	if (!info)
+		goto out;
+
+	ret = ufshcd_toggle_vreg(dev, info->vcc, on);
+	if (ret)
+		goto out;
+
+	ret = ufshcd_toggle_vreg(dev, info->vccq, on);
+	if (ret)
+		goto out;
+
+	ret = ufshcd_toggle_vreg(dev, info->vccq2, on);
+	if (ret)
+		goto out;
+
+out:
+	if (ret) {
+		ufshcd_toggle_vreg(dev, info->vccq2, false);
+		ufshcd_toggle_vreg(dev, info->vccq, false);
+		ufshcd_toggle_vreg(dev, info->vcc, false);
+	}
+	return ret;
+}
+
+static int ufshcd_setup_hba_vreg(struct ufs_hba *hba, bool on)
+{
+	struct ufs_vreg_info *info = &hba->vreg_info;
+
+	if (info)
+		return ufshcd_toggle_vreg(hba->dev, info->vdd_hba, on);
+
+	return 0;
+}
+
+static int ufshcd_get_vreg(struct device *dev, struct ufs_vreg *vreg)
+{
+	int ret = 0;
+
+	if (!vreg)
+		goto out;
+
+	vreg->reg = devm_regulator_get(dev, vreg->name);
+	if (IS_ERR(vreg->reg)) {
+		ret = PTR_ERR(vreg->reg);
+		dev_err(dev, "%s: %s get failed, err=%d\n",
+				__func__, vreg->name, ret);
+	}
+out:
+	return ret;
+}
+
+static int ufshcd_init_vreg(struct ufs_hba *hba)
+{
+	int ret = 0;
+	struct device *dev = hba->dev;
+	struct ufs_vreg_info *info = &hba->vreg_info;
+
+	if (!info)
+		goto out;
+
+	ret = ufshcd_get_vreg(dev, info->vcc);
+	if (ret)
+		goto out;
+
+	ret = ufshcd_get_vreg(dev, info->vccq);
+	if (ret)
+		goto out;
+
+	ret = ufshcd_get_vreg(dev, info->vccq2);
+out:
+	return ret;
+}
+
+static int ufshcd_init_hba_vreg(struct ufs_hba *hba)
+{
+	struct ufs_vreg_info *info = &hba->vreg_info;
+
+	if (info)
+		return ufshcd_get_vreg(hba->dev, info->vdd_hba);
+
+	return 0;
+}
+
+static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
+					bool skip_ref_clk)
+{
+	int ret = 0;
+	struct ufs_clk_info *clki;
+	struct list_head *head = &hba->clk_list_head;
+	unsigned long flags;
+
+	if (!head || list_empty(head))
+		goto out;
+
+	list_for_each_entry(clki, head, list) {
+		if (!IS_ERR_OR_NULL(clki->clk)) {
+			if (skip_ref_clk && !strcmp(clki->name, "ref_clk"))
+				continue;
+
+			if (on && !clki->enabled) {
+				ret = clk_prepare_enable(clki->clk);
+				if (ret) {
+					dev_err(hba->dev, "%s: %s prepare enable failed, %d\n",
+						__func__, clki->name, ret);
+					goto out;
+				}
+			} else if (!on && clki->enabled) {
+				clk_disable_unprepare(clki->clk);
+			}
+			clki->enabled = on;
+			dev_dbg(hba->dev, "%s: clk: %s %sabled\n", __func__,
+					clki->name, on ? "en" : "dis");
+		}
+	}
+
+	if (hba->vops && hba->vops->setup_clocks)
+		ret = hba->vops->setup_clocks(hba, on);
+out:
+	if (ret) {
+		list_for_each_entry(clki, head, list) {
+			if (!IS_ERR_OR_NULL(clki->clk) && clki->enabled)
+				clk_disable_unprepare(clki->clk);
+		}
+	} else if (on) {
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		hba->clk_gating.state = CLKS_ON;
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	}
+	return ret;
+}
+
+static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on)
+{
+	return  __ufshcd_setup_clocks(hba, on, false);
+}
+
+static int ufshcd_init_clocks(struct ufs_hba *hba)
+{
+	int ret = 0;
+	struct ufs_clk_info *clki;
+	struct device *dev = hba->dev;
+	struct list_head *head = &hba->clk_list_head;
+
+	if (!head || list_empty(head))
+		goto out;
+
+	list_for_each_entry(clki, head, list) {
+		if (!clki->name)
+			continue;
+
+		clki->clk = devm_clk_get(dev, clki->name);
+		if (IS_ERR(clki->clk)) {
+			ret = PTR_ERR(clki->clk);
+			dev_err(dev, "%s: %s clk get failed, %d\n",
+					__func__, clki->name, ret);
+			goto out;
+		}
+
+		if (clki->max_freq) {
+			ret = clk_set_rate(clki->clk, clki->max_freq);
+			if (ret) {
+				dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
+					__func__, clki->name,
+					clki->max_freq, ret);
+				goto out;
+			}
+			clki->curr_freq = clki->max_freq;
+		}
+		dev_dbg(dev, "%s: clk: %s, rate: %lu\n", __func__,
+				clki->name, clk_get_rate(clki->clk));
+	}
+out:
+	return ret;
+}
+
+static int ufshcd_variant_hba_init(struct ufs_hba *hba)
+{
+	int err = 0;
+
+	if (!hba->vops)
+		goto out;
+
+	if (hba->vops->init) {
+		err = hba->vops->init(hba);
+		if (err)
+			goto out;
+	}
+
+	if (hba->vops->setup_regulators) {
+		err = hba->vops->setup_regulators(hba, true);
+		if (err)
+			goto out_exit;
+	}
+
+	goto out;
+
+out_exit:
+	if (hba->vops->exit)
+		hba->vops->exit(hba);
+out:
+	if (err)
+		dev_err(hba->dev, "%s: variant %s init failed err %d\n",
+			__func__, hba->vops ? hba->vops->name : "", err);
+	return err;
+}
+
+static void ufshcd_variant_hba_exit(struct ufs_hba *hba)
+{
+	if (!hba->vops)
+		return;
+
+	if (hba->vops->setup_clocks)
+		hba->vops->setup_clocks(hba, false);
+
+	if (hba->vops->setup_regulators)
+		hba->vops->setup_regulators(hba, false);
+
+	if (hba->vops->exit)
+		hba->vops->exit(hba);
+}
+
+static int ufshcd_hba_init(struct ufs_hba *hba)
+{
+	int err;
+
+	/*
+	 * Handle host controller power separately from the UFS device power
+	 * rails as it will help controlling the UFS host controller power
+	 * collapse easily which is different than UFS device power collapse.
+	 * Also, enable the host controller power before we go ahead with rest
+	 * of the initialization here.
+	 */
+	err = ufshcd_init_hba_vreg(hba);
+	if (err)
+		goto out;
+
+	err = ufshcd_setup_hba_vreg(hba, true);
+	if (err)
+		goto out;
+
+	err = ufshcd_init_clocks(hba);
+	if (err)
+		goto out_disable_hba_vreg;
+
+	err = ufshcd_setup_clocks(hba, true);
+	if (err)
+		goto out_disable_hba_vreg;
+
+	err = ufshcd_init_vreg(hba);
+	if (err)
+		goto out_disable_clks;
+
+	err = ufshcd_setup_vreg(hba, true);
+	if (err)
+		goto out_disable_clks;
+
+	err = ufshcd_variant_hba_init(hba);
+	if (err)
+		goto out_disable_vreg;
+
+	hba->is_powered = true;
+	goto out;
+
+out_disable_vreg:
+	ufshcd_setup_vreg(hba, false);
+out_disable_clks:
+	ufshcd_setup_clocks(hba, false);
+out_disable_hba_vreg:
+	ufshcd_setup_hba_vreg(hba, false);
+out:
+	return err;
+}
+
+static void ufshcd_hba_exit(struct ufs_hba *hba)
+{
+	if (hba->is_powered) {
+		ufshcd_variant_hba_exit(hba);
+		ufshcd_setup_vreg(hba, false);
+		ufshcd_setup_clocks(hba, false);
+		ufshcd_setup_hba_vreg(hba, false);
+		hba->is_powered = false;
+	}
+}
+
+static int
+ufshcd_send_request_sense(struct ufs_hba *hba, struct scsi_device *sdp)
+{
+	unsigned char cmd[6] = {REQUEST_SENSE,
+				0,
+				0,
+				0,
+				SCSI_SENSE_BUFFERSIZE,
+				0};
+	char *buffer;
+	int ret;
+
+	buffer = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
+	if (!buffer) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = scsi_execute_req_flags(sdp, cmd, DMA_FROM_DEVICE, buffer,
+				SCSI_SENSE_BUFFERSIZE, NULL,
+				msecs_to_jiffies(1000), 3, NULL, REQ_PM);
+	if (ret)
+		pr_err("%s: failed with err %d\n", __func__, ret);
+
+	kfree(buffer);
+out:
+	return ret;
+}
+
+/**
+ * ufshcd_set_dev_pwr_mode - sends START STOP UNIT command to set device
+ *			     power mode
+ * @hba: per adapter instance
+ * @pwr_mode: device power mode to set
+ *
+ * Returns 0 if requested power mode is set successfully
+ * Returns non-zero if failed to set the requested power mode
+ */
+static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
+				     enum ufs_dev_pwr_mode pwr_mode)
+{
+	unsigned char cmd[6] = { START_STOP };
+	struct scsi_sense_hdr sshdr;
+	struct scsi_device *sdp;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	sdp = hba->sdev_ufs_device;
+	if (sdp) {
+		ret = scsi_device_get(sdp);
+		if (!ret && !scsi_device_online(sdp)) {
+			ret = -ENODEV;
+			scsi_device_put(sdp);
+		}
+	} else {
+		ret = -ENODEV;
+	}
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	if (ret)
+		return ret;
+
+	/*
+	 * If scsi commands fail, the scsi mid-layer schedules scsi error-
+	 * handling, which would wait for host to be resumed. Since we know
+	 * we are functional while we are here, skip host resume in error
+	 * handling context.
+	 */
+	hba->host->eh_noresume = 1;
+	if (hba->wlun_dev_clr_ua) {
+		ret = ufshcd_send_request_sense(hba, sdp);
+		if (ret)
+			goto out;
+		/* Unit attention condition is cleared now */
+		hba->wlun_dev_clr_ua = false;
+	}
+
+	cmd[4] = pwr_mode << 4;
+
+	/*
+	 * Current function would be generally called from the power management
+	 * callbacks hence set the REQ_PM flag so that it doesn't resume the
+	 * already suspended childs.
+	 */
+	ret = scsi_execute_req_flags(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
+				     START_STOP_TIMEOUT, 0, NULL, REQ_PM);
+	if (ret) {
+		sdev_printk(KERN_WARNING, sdp,
+			    "START_STOP failed for power mode: %d, result %x\n",
+			    pwr_mode, ret);
+		if (driver_byte(ret) & DRIVER_SENSE)
+			scsi_print_sense_hdr(sdp, NULL, &sshdr);
+	}
+
+	if (!ret)
+		hba->curr_dev_pwr_mode = pwr_mode;
+out:
+	scsi_device_put(sdp);
+	hba->host->eh_noresume = 0;
+	return ret;
+}
+
+static int ufshcd_link_state_transition(struct ufs_hba *hba,
+					enum uic_link_state req_link_state,
+					int check_for_bkops)
+{
+	int ret = 0;
+
+	if (req_link_state == hba->uic_link_state)
+		return 0;
+
+	if (req_link_state == UIC_LINK_HIBERN8_STATE) {
+		ret = ufshcd_uic_hibern8_enter(hba);
+		if (!ret)
+			ufshcd_set_link_hibern8(hba);
+		else
+			goto out;
+	}
+	/*
+	 * If autobkops is enabled, link can't be turned off because
+	 * turning off the link would also turn off the device.
+	 */
+	else if ((req_link_state == UIC_LINK_OFF_STATE) &&
+		   (!check_for_bkops || (check_for_bkops &&
+		    !hba->auto_bkops_enabled))) {
+		/*
+		 * Change controller state to "reset state" which
+		 * should also put the link in off/reset state
+		 */
+		ufshcd_hba_stop(hba);
+		/*
+		 * TODO: Check if we need any delay to make sure that
+		 * controller is reset
+		 */
+		ufshcd_set_link_off(hba);
+	}
+
+out:
+	return ret;
+}
+
+static void ufshcd_vreg_set_lpm(struct ufs_hba *hba)
+{
+	/*
+	 * If UFS device is either in UFS_Sleep turn off VCC rail to save some
+	 * power.
+	 *
+	 * If UFS device and link is in OFF state, all power supplies (VCC,
+	 * VCCQ, VCCQ2) can be turned off if power on write protect is not
+	 * required. If UFS link is inactive (Hibern8 or OFF state) and device
+	 * is in sleep state, put VCCQ & VCCQ2 rails in LPM mode.
+	 *
+	 * Ignore the error returned by ufshcd_toggle_vreg() as device is anyway
+	 * in low power state which would save some power.
+	 */
+	if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba) &&
+	    !hba->dev_info.is_lu_power_on_wp) {
+		ufshcd_setup_vreg(hba, false);
+	} else if (!ufshcd_is_ufs_dev_active(hba)) {
+		ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false);
+		if (!ufshcd_is_link_active(hba)) {
+			ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq);
+			ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2);
+		}
+	}
+}
+
+static int ufshcd_vreg_set_hpm(struct ufs_hba *hba)
+{
+	int ret = 0;
+
+	if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba) &&
+	    !hba->dev_info.is_lu_power_on_wp) {
+		ret = ufshcd_setup_vreg(hba, true);
+	} else if (!ufshcd_is_ufs_dev_active(hba)) {
+		ret = ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, true);
+		if (!ret && !ufshcd_is_link_active(hba)) {
+			ret = ufshcd_config_vreg_hpm(hba, hba->vreg_info.vccq);
+			if (ret)
+				goto vcc_disable;
+			ret = ufshcd_config_vreg_hpm(hba, hba->vreg_info.vccq2);
+			if (ret)
+				goto vccq_lpm;
+		}
+	}
+	goto out;
+
+vccq_lpm:
+	ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq);
+vcc_disable:
+	ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false);
+out:
+	return ret;
+}
+
+static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba)
+{
+	if (ufshcd_is_link_off(hba))
+		ufshcd_setup_hba_vreg(hba, false);
+}
+
+static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
+{
+	if (ufshcd_is_link_off(hba))
+		ufshcd_setup_hba_vreg(hba, true);
+}
+
+/**
+ * ufshcd_suspend - helper function for suspend operations
+ * @hba: per adapter instance
+ * @pm_op: desired low power operation type
+ *
+ * This function will try to put the UFS device and link into low power
+ * mode based on the "rpm_lvl" (Runtime PM level) or "spm_lvl"
+ * (System PM level).
+ *
+ * If this function is called during shutdown, it will make sure that
+ * both UFS device and UFS link is powered off.
+ *
+ * NOTE: UFS device & link must be active before we enter in this function.
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+{
+	int ret = 0;
+	enum ufs_pm_level pm_lvl;
+	enum ufs_dev_pwr_mode req_dev_pwr_mode;
+	enum uic_link_state req_link_state;
+
+	hba->pm_op_in_progress = 1;
+	if (!ufshcd_is_shutdown_pm(pm_op)) {
+		pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
+			 hba->rpm_lvl : hba->spm_lvl;
+		req_dev_pwr_mode = ufs_get_pm_lvl_to_dev_pwr_mode(pm_lvl);
+		req_link_state = ufs_get_pm_lvl_to_link_pwr_state(pm_lvl);
+	} else {
+		req_dev_pwr_mode = UFS_POWERDOWN_PWR_MODE;
+		req_link_state = UIC_LINK_OFF_STATE;
+	}
+
+	/*
+	 * If we can't transition into any of the low power modes
+	 * just gate the clocks.
+	 */
+	ufshcd_hold(hba, false);
+	hba->clk_gating.is_suspended = true;
+
+	if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE &&
+			req_link_state == UIC_LINK_ACTIVE_STATE) {
+		goto disable_clks;
+	}
+
+	if ((req_dev_pwr_mode == hba->curr_dev_pwr_mode) &&
+	    (req_link_state == hba->uic_link_state))
+		goto out;
+
+	/* UFS device & link must be active before we enter in this function */
+	if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (ufshcd_is_runtime_pm(pm_op)) {
+		if (ufshcd_can_autobkops_during_suspend(hba)) {
+			/*
+			 * The device is idle with no requests in the queue,
+			 * allow background operations if bkops status shows
+			 * that performance might be impacted.
+			 */
+			ret = ufshcd_urgent_bkops(hba);
+			if (ret)
+				goto enable_gating;
+		} else {
+			/* make sure that auto bkops is disabled */
+			ufshcd_disable_auto_bkops(hba);
+		}
+	}
+
+	if ((req_dev_pwr_mode != hba->curr_dev_pwr_mode) &&
+	     ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) ||
+	       !ufshcd_is_runtime_pm(pm_op))) {
+		/* ensure that bkops is disabled */
+		ufshcd_disable_auto_bkops(hba);
+		ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
+		if (ret)
+			goto enable_gating;
+	}
+
+	ret = ufshcd_link_state_transition(hba, req_link_state, 1);
+	if (ret)
+		goto set_dev_active;
+
+	ufshcd_vreg_set_lpm(hba);
+
+disable_clks:
+	/*
+	 * The clock scaling needs access to controller registers. Hence, Wait
+	 * for pending clock scaling work to be done before clocks are
+	 * turned off.
+	 */
+	if (ufshcd_is_clkscaling_enabled(hba)) {
+		devfreq_suspend_device(hba->devfreq);
+		hba->clk_scaling.window_start_t = 0;
+	}
+	/*
+	 * Call vendor specific suspend callback. As these callbacks may access
+	 * vendor specific host controller register space call them before the
+	 * host clocks are ON.
+	 */
+	if (hba->vops && hba->vops->suspend) {
+		ret = hba->vops->suspend(hba, pm_op);
+		if (ret)
+			goto set_link_active;
+	}
+
+	if (hba->vops && hba->vops->setup_clocks) {
+		ret = hba->vops->setup_clocks(hba, false);
+		if (ret)
+			goto vops_resume;
+	}
+
+	if (!ufshcd_is_link_active(hba))
+		ufshcd_setup_clocks(hba, false);
+	else
+		/* If link is active, device ref_clk can't be switched off */
+		__ufshcd_setup_clocks(hba, false, true);
+
+	hba->clk_gating.state = CLKS_OFF;
+	/*
+	 * Disable the host irq as host controller as there won't be any
+	 * host controller trasanction expected till resume.
+	 */
+	ufshcd_disable_irq(hba);
+	/* Put the host controller in low power mode if possible */
+	ufshcd_hba_vreg_set_lpm(hba);
+	goto out;
+
+vops_resume:
+	if (hba->vops && hba->vops->resume)
+		hba->vops->resume(hba, pm_op);
+set_link_active:
+	ufshcd_vreg_set_hpm(hba);
+	if (ufshcd_is_link_hibern8(hba) && !ufshcd_uic_hibern8_exit(hba))
+		ufshcd_set_link_active(hba);
+	else if (ufshcd_is_link_off(hba))
+		ufshcd_host_reset_and_restore(hba);
+set_dev_active:
+	if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
+		ufshcd_disable_auto_bkops(hba);
+enable_gating:
+	hba->clk_gating.is_suspended = false;
+	ufshcd_release(hba);
+out:
+	hba->pm_op_in_progress = 0;
+	return ret;
+}
+
+/**
+ * ufshcd_resume - helper function for resume operations
+ * @hba: per adapter instance
+ * @pm_op: runtime PM or system PM
+ *
+ * This function basically brings the UFS device, UniPro link and controller
+ * to active state.
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+{
+	int ret;
+	enum uic_link_state old_link_state;
+
+	hba->pm_op_in_progress = 1;
+	old_link_state = hba->uic_link_state;
+
+	ufshcd_hba_vreg_set_hpm(hba);
+	/* Make sure clocks are enabled before accessing controller */
+	ret = ufshcd_setup_clocks(hba, true);
+	if (ret)
+		goto out;
+
+	/* enable the host irq as host controller would be active soon */
+	ret = ufshcd_enable_irq(hba);
+	if (ret)
+		goto disable_irq_and_vops_clks;
+
+	ret = ufshcd_vreg_set_hpm(hba);
+	if (ret)
+		goto disable_irq_and_vops_clks;
+
+	/*
+	 * Call vendor specific resume callback. As these callbacks may access
+	 * vendor specific host controller register space call them when the
+	 * host clocks are ON.
+	 */
+	if (hba->vops && hba->vops->resume) {
+		ret = hba->vops->resume(hba, pm_op);
+		if (ret)
+			goto disable_vreg;
+	}
+
+	if (ufshcd_is_link_hibern8(hba)) {
+		ret = ufshcd_uic_hibern8_exit(hba);
+		if (!ret)
+			ufshcd_set_link_active(hba);
+		else
+			goto vendor_suspend;
+	} else if (ufshcd_is_link_off(hba)) {
+		ret = ufshcd_host_reset_and_restore(hba);
+		/*
+		 * ufshcd_host_reset_and_restore() should have already
+		 * set the link state as active
+		 */
+		if (ret || !ufshcd_is_link_active(hba))
+			goto vendor_suspend;
+	}
+
+	if (!ufshcd_is_ufs_dev_active(hba)) {
+		ret = ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE);
+		if (ret)
+			goto set_old_link_state;
+	}
+
+	/*
+	 * If BKOPs operations are urgently needed at this moment then
+	 * keep auto-bkops enabled or else disable it.
+	 */
+	ufshcd_urgent_bkops(hba);
+	hba->clk_gating.is_suspended = false;
+
+	if (ufshcd_is_clkscaling_enabled(hba))
+		devfreq_resume_device(hba->devfreq);
+
+	/* Schedule clock gating in case of no access to UFS device yet */
+	ufshcd_release(hba);
+	goto out;
+
+set_old_link_state:
+	ufshcd_link_state_transition(hba, old_link_state, 0);
+vendor_suspend:
+	if (hba->vops && hba->vops->suspend)
+		hba->vops->suspend(hba, pm_op);
+disable_vreg:
+	ufshcd_vreg_set_lpm(hba);
+disable_irq_and_vops_clks:
+	ufshcd_disable_irq(hba);
+	ufshcd_setup_clocks(hba, false);
+out:
+	hba->pm_op_in_progress = 0;
+	return ret;
+}
+
+/**
+ * ufshcd_system_suspend - system suspend routine
+ * @hba: per adapter instance
+ * @pm_op: runtime PM or system PM
+ *
+ * Check the description of ufshcd_suspend() function for more details.
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+int ufshcd_system_suspend(struct ufs_hba *hba)
+{
+	int ret = 0;
+
+	if (!hba || !hba->is_powered)
+		return 0;
+
+	if (pm_runtime_suspended(hba->dev)) {
+		if (hba->rpm_lvl == hba->spm_lvl)
+			/*
+			 * There is possibility that device may still be in
+			 * active state during the runtime suspend.
+			 */
+			if ((ufs_get_pm_lvl_to_dev_pwr_mode(hba->spm_lvl) ==
+			    hba->curr_dev_pwr_mode) && !hba->auto_bkops_enabled)
+				goto out;
+
+		/*
+		 * UFS device and/or UFS link low power states during runtime
+		 * suspend seems to be different than what is expected during
+		 * system suspend. Hence runtime resume the devic & link and
+		 * let the system suspend low power states to take effect.
+		 * TODO: If resume takes longer time, we might have optimize
+		 * it in future by not resuming everything if possible.
+		 */
+		ret = ufshcd_runtime_resume(hba);
+		if (ret)
+			goto out;
+	}
+
+	ret = ufshcd_suspend(hba, UFS_SYSTEM_PM);
+out:
+	if (!ret)
+		hba->is_sys_suspended = true;
+	return ret;
+}
+EXPORT_SYMBOL(ufshcd_system_suspend);
+
+/**
+ * ufshcd_system_resume - system resume routine
+ * @hba: per adapter instance
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+
+int ufshcd_system_resume(struct ufs_hba *hba)
+{
+	if (!hba || !hba->is_powered || pm_runtime_suspended(hba->dev))
+		/*
+		 * Let the runtime resume take care of resuming
+		 * if runtime suspended.
+		 */
+		return 0;
+
+	return ufshcd_resume(hba, UFS_SYSTEM_PM);
+}
+EXPORT_SYMBOL(ufshcd_system_resume);
+
+/**
+ * ufshcd_runtime_suspend - runtime suspend routine
+ * @hba: per adapter instance
+ *
+ * Check the description of ufshcd_suspend() function for more details.
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+int ufshcd_runtime_suspend(struct ufs_hba *hba)
+{
+	if (!hba || !hba->is_powered)
+		return 0;
+
+	return ufshcd_suspend(hba, UFS_RUNTIME_PM);
+}
+EXPORT_SYMBOL(ufshcd_runtime_suspend);
+
+/**
+ * ufshcd_runtime_resume - runtime resume routine
+ * @hba: per adapter instance
+ *
+ * This function basically brings the UFS device, UniPro link and controller
+ * to active state. Following operations are done in this function:
+ *
+ * 1. Turn on all the controller related clocks
+ * 2. Bring the UniPro link out of Hibernate state
+ * 3. If UFS device is in sleep state, turn ON VCC rail and bring the UFS device
+ *    to active state.
+ * 4. If auto-bkops is enabled on the device, disable it.
+ *
+ * So following would be the possible power state after this function return
+ * successfully:
+ *	S1: UFS device in Active state with VCC rail ON
+ *	    UniPro link in Active state
+ *	    All the UFS/UniPro controller clocks are ON
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+int ufshcd_runtime_resume(struct ufs_hba *hba)
+{
+	if (!hba || !hba->is_powered)
+		return 0;
+	else
+		return ufshcd_resume(hba, UFS_RUNTIME_PM);
+}
+EXPORT_SYMBOL(ufshcd_runtime_resume);
+
+int ufshcd_runtime_idle(struct ufs_hba *hba)
+{
+	return 0;
+}
+EXPORT_SYMBOL(ufshcd_runtime_idle);
+
+/**
+ * ufshcd_shutdown - shutdown routine
+ * @hba: per adapter instance
+ *
+ * This function would power off both UFS device and UFS link.
+ *
+ * Returns 0 always to allow force shutdown even in case of errors.
+ */
+int ufshcd_shutdown(struct ufs_hba *hba)
+{
+	int ret = 0;
+
+	if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba))
+		goto out;
+
+	if (pm_runtime_suspended(hba->dev)) {
+		ret = ufshcd_runtime_resume(hba);
+		if (ret)
+			goto out;
+	}
+
+	ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM);
+out:
+	if (ret)
+		dev_err(hba->dev, "%s failed, err %d\n", __func__, ret);
+	/* allow force shutdown even in case of errors */
+	return 0;
+}
+EXPORT_SYMBOL(ufshcd_shutdown);
+
+/**
+ * ufshcd_remove - de-allocate SCSI host and host memory space
+ *		data structure memory
+ * @hba - per adapter instance
+ */
+void ufshcd_remove(struct ufs_hba *hba)
+{
+	scsi_remove_host(hba->host);
+	/* disable interrupts */
+	ufshcd_disable_intr(hba, hba->intr_mask);
+	ufshcd_hba_stop(hba);
+
+	scsi_host_put(hba->host);
+
+	ufshcd_exit_clk_gating(hba);
+	if (ufshcd_is_clkscaling_enabled(hba))
+		devfreq_remove_device(hba->devfreq);
+	ufshcd_hba_exit(hba);
+}
+EXPORT_SYMBOL_GPL(ufshcd_remove);
+
+/**
+ * ufshcd_set_dma_mask - Set dma mask based on the controller
+ *			 addressing capability
+ * @hba: per adapter instance
+ *
+ * Returns 0 for success, non-zero for failure
+ */
+static int ufshcd_set_dma_mask(struct ufs_hba *hba)
+{
+	if (hba->capabilities & MASK_64_ADDRESSING_SUPPORT) {
+		if (!dma_set_mask_and_coherent(hba->dev, DMA_BIT_MASK(64)))
+			return 0;
+	}
+	return dma_set_mask_and_coherent(hba->dev, DMA_BIT_MASK(32));
+}
+
+/**
+ * ufshcd_alloc_host - allocate Host Bus Adapter (HBA)
+ * @dev: pointer to device handle
+ * @hba_handle: driver private handle
+ * Returns 0 on success, non-zero value on failure
+ */
+int ufshcd_alloc_host(struct device *dev, struct ufs_hba **hba_handle)
+{
+	struct Scsi_Host *host;
+	struct ufs_hba *hba;
+	int err = 0;
+
+	if (!dev) {
+		dev_err(dev,
+		"Invalid memory reference for dev is NULL\n");
+		err = -ENODEV;
+		goto out_error;
+	}
+
+	host = scsi_host_alloc(&ufshcd_driver_template,
+				sizeof(struct ufs_hba));
+	if (!host) {
+		dev_err(dev, "scsi_host_alloc failed\n");
+		err = -ENOMEM;
+		goto out_error;
+	}
+	hba = shost_priv(host);
+	hba->host = host;
+	hba->dev = dev;
+	*hba_handle = hba;
+
+out_error:
+	return err;
+}
+EXPORT_SYMBOL(ufshcd_alloc_host);
+
+static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
+{
+	int ret = 0;
+	struct ufs_clk_info *clki;
+	struct list_head *head = &hba->clk_list_head;
+
+	if (!head || list_empty(head))
+		goto out;
+
+	list_for_each_entry(clki, head, list) {
+		if (!IS_ERR_OR_NULL(clki->clk)) {
+			if (scale_up && clki->max_freq) {
+				if (clki->curr_freq == clki->max_freq)
+					continue;
+				ret = clk_set_rate(clki->clk, clki->max_freq);
+				if (ret) {
+					dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
+						__func__, clki->name,
+						clki->max_freq, ret);
+					break;
+				}
+				clki->curr_freq = clki->max_freq;
+
+			} else if (!scale_up && clki->min_freq) {
+				if (clki->curr_freq == clki->min_freq)
+					continue;
+				ret = clk_set_rate(clki->clk, clki->min_freq);
+				if (ret) {
+					dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
+						__func__, clki->name,
+						clki->min_freq, ret);
+					break;
+				}
+				clki->curr_freq = clki->min_freq;
+			}
+		}
+		dev_dbg(hba->dev, "%s: clk: %s, rate: %lu\n", __func__,
+				clki->name, clk_get_rate(clki->clk));
+	}
+	if (hba->vops->clk_scale_notify)
+		hba->vops->clk_scale_notify(hba);
+out:
+	return ret;
+}
+
+static int ufshcd_devfreq_target(struct device *dev,
+				unsigned long *freq, u32 flags)
+{
+	int err = 0;
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+
+	if (!ufshcd_is_clkscaling_enabled(hba))
+		return -EINVAL;
+
+	if (*freq == UINT_MAX)
+		err = ufshcd_scale_clks(hba, true);
+	else if (*freq == 0)
+		err = ufshcd_scale_clks(hba, false);
+
+	return err;
+}
+
+static int ufshcd_devfreq_get_dev_status(struct device *dev,
+		struct devfreq_dev_status *stat)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	struct ufs_clk_scaling *scaling = &hba->clk_scaling;
+	unsigned long flags;
+
+	if (!ufshcd_is_clkscaling_enabled(hba))
+		return -EINVAL;
+
+	memset(stat, 0, sizeof(*stat));
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (!scaling->window_start_t)
+		goto start_window;
+
+	if (scaling->is_busy_started)
+		scaling->tot_busy_t += ktime_to_us(ktime_sub(ktime_get(),
+					scaling->busy_start_t));
+
+	stat->total_time = jiffies_to_usecs((long)jiffies -
+				(long)scaling->window_start_t);
+	stat->busy_time = scaling->tot_busy_t;
+start_window:
+	scaling->window_start_t = jiffies;
+	scaling->tot_busy_t = 0;
+
+	if (hba->outstanding_reqs) {
+		scaling->busy_start_t = ktime_get();
+		scaling->is_busy_started = true;
+	} else {
+		scaling->busy_start_t = ktime_set(0, 0);
+		scaling->is_busy_started = false;
+	}
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	return 0;
+}
+
+static struct devfreq_dev_profile ufs_devfreq_profile = {
+	.polling_ms	= 100,
+	.target		= ufshcd_devfreq_target,
+	.get_dev_status	= ufshcd_devfreq_get_dev_status,
+};
+
+/**
+ * ufshcd_init - Driver initialization routine
+ * @hba: per-adapter instance
+ * @mmio_base: base register address
+ * @irq: Interrupt line of device
+ * Returns 0 on success, non-zero value on failure
+ */
+int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
+{
+	int err;
+	struct Scsi_Host *host = hba->host;
+	struct device *dev = hba->dev;
+
+	if (!mmio_base) {
+		dev_err(hba->dev,
+		"Invalid memory reference for mmio_base is NULL\n");
+		err = -ENODEV;
+		goto out_error;
+	}
+
+	hba->mmio_base = mmio_base;
+	hba->irq = irq;
+
+	err = ufshcd_hba_init(hba);
+	if (err)
+		goto out_error;
+
+	/* Read capabilities registers */
+	ufshcd_hba_capabilities(hba);
+
+	/* Get UFS version supported by the controller */
+	hba->ufs_version = ufshcd_get_ufs_version(hba);
+
+	/* Get Interrupt bit mask per version */
+	hba->intr_mask = ufshcd_get_intr_mask(hba);
+
+	err = ufshcd_set_dma_mask(hba);
+	if (err) {
+		dev_err(hba->dev, "set dma mask failed\n");
+		goto out_disable;
+	}
+
+	/* Allocate memory for host memory space */
+	err = ufshcd_memory_alloc(hba);
+	if (err) {
+		dev_err(hba->dev, "Memory allocation failed\n");
+		goto out_disable;
+	}
+
+	/* Configure LRB */
+	ufshcd_host_memory_configure(hba);
+
+	host->can_queue = hba->nutrs;
+	host->cmd_per_lun = hba->nutrs;
+	host->max_id = UFSHCD_MAX_ID;
+	host->max_lun = UFS_MAX_LUNS;
+	host->max_channel = UFSHCD_MAX_CHANNEL;
+	host->unique_id = host->host_no;
+	host->max_cmd_len = MAX_CDB_SIZE;
+
+	hba->max_pwr_info.is_valid = false;
+
+	/* Initailize wait queue for task management */
+	init_waitqueue_head(&hba->tm_wq);
+	init_waitqueue_head(&hba->tm_tag_wq);
+
+	/* Initialize work queues */
+	INIT_WORK(&hba->eh_work, ufshcd_err_handler);
+	INIT_WORK(&hba->eeh_work, ufshcd_exception_event_handler);
+
+	/* Initialize UIC command mutex */
+	mutex_init(&hba->uic_cmd_mutex);
+
+	/* Initialize mutex for device management commands */
+	mutex_init(&hba->dev_cmd.lock);
+
+	/* Initialize device management tag acquire wait queue */
+	init_waitqueue_head(&hba->dev_cmd.tag_wq);
+
+	ufshcd_init_clk_gating(hba);
+	/* IRQ registration */
+	err = devm_request_irq(dev, irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba);
+	if (err) {
+		dev_err(hba->dev, "request irq failed\n");
+		goto exit_gating;
+	} else {
+		hba->is_irq_enabled = true;
+	}
+
+	/* Enable SCSI tag mapping */
+	err = scsi_init_shared_tag_map(host, host->can_queue);
+	if (err) {
+		dev_err(hba->dev, "init shared queue failed\n");
+		goto exit_gating;
+	}
+
+	err = scsi_add_host(host, hba->dev);
+	if (err) {
+		dev_err(hba->dev, "scsi_add_host failed\n");
+		goto exit_gating;
+	}
+
+	/* Host controller enable */
+	err = ufshcd_hba_enable(hba);
+	if (err) {
+		dev_err(hba->dev, "Host controller enable failed\n");
+		goto out_remove_scsi_host;
+	}
+
+	if (ufshcd_is_clkscaling_enabled(hba)) {
+		hba->devfreq = devfreq_add_device(dev, &ufs_devfreq_profile,
+						   "simple_ondemand", NULL);
+		if (IS_ERR(hba->devfreq)) {
+			dev_err(hba->dev, "Unable to register with devfreq %ld\n",
+					PTR_ERR(hba->devfreq));
+			goto out_remove_scsi_host;
+		}
+		/* Suspend devfreq until the UFS device is detected */
+		devfreq_suspend_device(hba->devfreq);
+		hba->clk_scaling.window_start_t = 0;
+	}
+
+	/* Hold auto suspend until async scan completes */
+	pm_runtime_get_sync(dev);
+
+	/*
+	 * The device-initialize-sequence hasn't been invoked yet.
+	 * Set the device to power-off state
+	 */
+	ufshcd_set_ufs_dev_poweroff(hba);
+
+	async_schedule(ufshcd_async_scan, hba);
+
+	return 0;
+
+out_remove_scsi_host:
+	scsi_remove_host(hba->host);
+exit_gating:
+	ufshcd_exit_clk_gating(hba);
+out_disable:
+	hba->is_irq_enabled = false;
+	scsi_host_put(host);
+	ufshcd_hba_exit(hba);
+out_error:
+	return err;
+}
+EXPORT_SYMBOL_GPL(ufshcd_init);
+
+MODULE_AUTHOR("Santosh Yaragnavi <santosh.sy@samsung.com>");
+MODULE_AUTHOR("Vinayak Holikatti <h.vinayak@samsung.com>");
+MODULE_DESCRIPTION("Generic UFS host controller driver Core");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(UFSHCD_DRIVER_VERSION);