Initial import

1 files changed, 596 insertions, 0 deletions

diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
new file mode 100644
index 000000000..8be0df758
--- /dev/null
+++ b/drivers/mmc/core/host.c
@@ -0,0 +1,596 @@
+/*
+ *  linux/drivers/mmc/core/host.c
+ *
+ *  Copyright (C) 2003 Russell King, All Rights Reserved.
+ *  Copyright (C) 2007-2008 Pierre Ossman
+ *  Copyright (C) 2010 Linus Walleij
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  MMC host class device management
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/pagemap.h>
+#include <linux/export.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+
+#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
+#include <linux/mmc/slot-gpio.h>
+
+#include "core.h"
+#include "host.h"
+#include "slot-gpio.h"
+#include "pwrseq.h"
+
+#define cls_dev_to_mmc_host(d)	container_of(d, struct mmc_host, class_dev)
+
+static DEFINE_IDR(mmc_host_idr);
+static DEFINE_SPINLOCK(mmc_host_lock);
+
+static void mmc_host_classdev_release(struct device *dev)
+{
+	struct mmc_host *host = cls_dev_to_mmc_host(dev);
+	spin_lock(&mmc_host_lock);
+	idr_remove(&mmc_host_idr, host->index);
+	spin_unlock(&mmc_host_lock);
+	kfree(host);
+}
+
+static struct class mmc_host_class = {
+	.name		= "mmc_host",
+	.dev_release	= mmc_host_classdev_release,
+};
+
+int mmc_register_host_class(void)
+{
+	return class_register(&mmc_host_class);
+}
+
+void mmc_unregister_host_class(void)
+{
+	class_unregister(&mmc_host_class);
+}
+
+#ifdef CONFIG_MMC_CLKGATE
+static ssize_t clkgate_delay_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct mmc_host *host = cls_dev_to_mmc_host(dev);
+	return snprintf(buf, PAGE_SIZE, "%lu\n", host->clkgate_delay);
+}
+
+static ssize_t clkgate_delay_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct mmc_host *host = cls_dev_to_mmc_host(dev);
+	unsigned long flags, value;
+
+	if (kstrtoul(buf, 0, &value))
+		return -EINVAL;
+
+	spin_lock_irqsave(&host->clk_lock, flags);
+	host->clkgate_delay = value;
+	spin_unlock_irqrestore(&host->clk_lock, flags);
+	return count;
+}
+
+/*
+ * Enabling clock gating will make the core call out to the host
+ * once up and once down when it performs a request or card operation
+ * intermingled in any fashion. The driver will see this through
+ * set_ios() operations with ios.clock field set to 0 to gate (disable)
+ * the block clock, and to the old frequency to enable it again.
+ */
+static void mmc_host_clk_gate_delayed(struct mmc_host *host)
+{
+	unsigned long tick_ns;
+	unsigned long freq = host->ios.clock;
+	unsigned long flags;
+
+	if (!freq) {
+		pr_debug("%s: frequency set to 0 in disable function, "
+			 "this means the clock is already disabled.\n",
+			 mmc_hostname(host));
+		return;
+	}
+	/*
+	 * New requests may have appeared while we were scheduling,
+	 * then there is no reason to delay the check before
+	 * clk_disable().
+	 */
+	spin_lock_irqsave(&host->clk_lock, flags);
+
+	/*
+	 * Delay n bus cycles (at least 8 from MMC spec) before attempting
+	 * to disable the MCI block clock. The reference count may have
+	 * gone up again after this delay due to rescheduling!
+	 */
+	if (!host->clk_requests) {
+		spin_unlock_irqrestore(&host->clk_lock, flags);
+		tick_ns = DIV_ROUND_UP(1000000000, freq);
+		ndelay(host->clk_delay * tick_ns);
+	} else {
+		/* New users appeared while waiting for this work */
+		spin_unlock_irqrestore(&host->clk_lock, flags);
+		return;
+	}
+	mutex_lock(&host->clk_gate_mutex);
+	spin_lock_irqsave(&host->clk_lock, flags);
+	if (!host->clk_requests) {
+		spin_unlock_irqrestore(&host->clk_lock, flags);
+		/* This will set host->ios.clock to 0 */
+		mmc_gate_clock(host);
+		spin_lock_irqsave(&host->clk_lock, flags);
+		pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
+	}
+	spin_unlock_irqrestore(&host->clk_lock, flags);
+	mutex_unlock(&host->clk_gate_mutex);
+}
+
+/*
+ * Internal work. Work to disable the clock at some later point.
+ */
+static void mmc_host_clk_gate_work(struct work_struct *work)
+{
+	struct mmc_host *host = container_of(work, struct mmc_host,
+					      clk_gate_work.work);
+
+	mmc_host_clk_gate_delayed(host);
+}
+
+/**
+ *	mmc_host_clk_hold - ungate hardware MCI clocks
+ *	@host: host to ungate.
+ *
+ *	Makes sure the host ios.clock is restored to a non-zero value
+ *	past this call.	Increase clock reference count and ungate clock
+ *	if we're the first user.
+ */
+void mmc_host_clk_hold(struct mmc_host *host)
+{
+	unsigned long flags;
+
+	/* cancel any clock gating work scheduled by mmc_host_clk_release() */
+	cancel_delayed_work_sync(&host->clk_gate_work);
+	mutex_lock(&host->clk_gate_mutex);
+	spin_lock_irqsave(&host->clk_lock, flags);
+	if (host->clk_gated) {
+		spin_unlock_irqrestore(&host->clk_lock, flags);
+		mmc_ungate_clock(host);
+		spin_lock_irqsave(&host->clk_lock, flags);
+		pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
+	}
+	host->clk_requests++;
+	spin_unlock_irqrestore(&host->clk_lock, flags);
+	mutex_unlock(&host->clk_gate_mutex);
+}
+
+/**
+ *	mmc_host_may_gate_card - check if this card may be gated
+ *	@card: card to check.
+ */
+static bool mmc_host_may_gate_card(struct mmc_card *card)
+{
+	/* If there is no card we may gate it */
+	if (!card)
+		return true;
+	/*
+	 * Don't gate SDIO cards! These need to be clocked at all times
+	 * since they may be independent systems generating interrupts
+	 * and other events. The clock requests counter from the core will
+	 * go down to zero since the core does not need it, but we will not
+	 * gate the clock, because there is somebody out there that may still
+	 * be using it.
+	 */
+	return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
+}
+
+/**
+ *	mmc_host_clk_release - gate off hardware MCI clocks
+ *	@host: host to gate.
+ *
+ *	Calls the host driver with ios.clock set to zero as often as possible
+ *	in order to gate off hardware MCI clocks. Decrease clock reference
+ *	count and schedule disabling of clock.
+ */
+void mmc_host_clk_release(struct mmc_host *host)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->clk_lock, flags);
+	host->clk_requests--;
+	if (mmc_host_may_gate_card(host->card) &&
+	    !host->clk_requests)
+		schedule_delayed_work(&host->clk_gate_work,
+				      msecs_to_jiffies(host->clkgate_delay));
+	spin_unlock_irqrestore(&host->clk_lock, flags);
+}
+
+/**
+ *	mmc_host_clk_rate - get current clock frequency setting
+ *	@host: host to get the clock frequency for.
+ *
+ *	Returns current clock frequency regardless of gating.
+ */
+unsigned int mmc_host_clk_rate(struct mmc_host *host)
+{
+	unsigned long freq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->clk_lock, flags);
+	if (host->clk_gated)
+		freq = host->clk_old;
+	else
+		freq = host->ios.clock;
+	spin_unlock_irqrestore(&host->clk_lock, flags);
+	return freq;
+}
+
+/**
+ *	mmc_host_clk_init - set up clock gating code
+ *	@host: host with potential clock to control
+ */
+static inline void mmc_host_clk_init(struct mmc_host *host)
+{
+	host->clk_requests = 0;
+	/* Hold MCI clock for 8 cycles by default */
+	host->clk_delay = 8;
+	/*
+	 * Default clock gating delay is 0ms to avoid wasting power.
+	 * This value can be tuned by writing into sysfs entry.
+	 */
+	host->clkgate_delay = 0;
+	host->clk_gated = false;
+	INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
+	spin_lock_init(&host->clk_lock);
+	mutex_init(&host->clk_gate_mutex);
+}
+
+/**
+ *	mmc_host_clk_exit - shut down clock gating code
+ *	@host: host with potential clock to control
+ */
+static inline void mmc_host_clk_exit(struct mmc_host *host)
+{
+	/*
+	 * Wait for any outstanding gate and then make sure we're
+	 * ungated before exiting.
+	 */
+	if (cancel_delayed_work_sync(&host->clk_gate_work))
+		mmc_host_clk_gate_delayed(host);
+	if (host->clk_gated)
+		mmc_host_clk_hold(host);
+	/* There should be only one user now */
+	WARN_ON(host->clk_requests > 1);
+}
+
+static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
+{
+	host->clkgate_delay_attr.show = clkgate_delay_show;
+	host->clkgate_delay_attr.store = clkgate_delay_store;
+	sysfs_attr_init(&host->clkgate_delay_attr.attr);
+	host->clkgate_delay_attr.attr.name = "clkgate_delay";
+	host->clkgate_delay_attr.attr.mode = S_IRUGO | S_IWUSR;
+	if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
+		pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
+				mmc_hostname(host));
+}
+#else
+
+static inline void mmc_host_clk_init(struct mmc_host *host)
+{
+}
+
+static inline void mmc_host_clk_exit(struct mmc_host *host)
+{
+}
+
+static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
+{
+}
+
+#endif
+
+/**
+ *	mmc_of_parse() - parse host's device-tree node
+ *	@host: host whose node should be parsed.
+ *
+ * To keep the rest of the MMC subsystem unaware of whether DT has been
+ * used to to instantiate and configure this host instance or not, we
+ * parse the properties and set respective generic mmc-host flags and
+ * parameters.
+ */
+int mmc_of_parse(struct mmc_host *host)
+{
+	struct device_node *np;
+	u32 bus_width;
+	int len, ret;
+	bool cd_cap_invert, cd_gpio_invert = false;
+	bool ro_cap_invert, ro_gpio_invert = false;
+
+	if (!host->parent || !host->parent->of_node)
+		return 0;
+
+	np = host->parent->of_node;
+
+	/* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
+	if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
+		dev_dbg(host->parent,
+			"\"bus-width\" property is missing, assuming 1 bit.\n");
+		bus_width = 1;
+	}
+
+	switch (bus_width) {
+	case 8:
+		host->caps |= MMC_CAP_8_BIT_DATA;
+		/* Hosts capable of 8-bit transfers can also do 4 bits */
+	case 4:
+		host->caps |= MMC_CAP_4_BIT_DATA;
+		break;
+	case 1:
+		break;
+	default:
+		dev_err(host->parent,
+			"Invalid \"bus-width\" value %u!\n", bus_width);
+		return -EINVAL;
+	}
+
+	/* f_max is obtained from the optional "max-frequency" property */
+	of_property_read_u32(np, "max-frequency", &host->f_max);
+
+	/*
+	 * Configure CD and WP pins. They are both by default active low to
+	 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
+	 * mmc-gpio helpers are used to attach, configure and use them. If
+	 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
+	 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
+	 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
+	 * is set. If the "non-removable" property is found, the
+	 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
+	 * configuration is performed.
+	 */
+
+	/* Parse Card Detection */
+	if (of_find_property(np, "non-removable", &len)) {
+		host->caps |= MMC_CAP_NONREMOVABLE;
+	} else {
+		cd_cap_invert = of_property_read_bool(np, "cd-inverted");
+
+		if (of_find_property(np, "broken-cd", &len))
+			host->caps |= MMC_CAP_NEEDS_POLL;
+
+		ret = mmc_gpiod_request_cd(host, "cd", 0, true,
+					   0, &cd_gpio_invert);
+		if (!ret)
+			dev_info(host->parent, "Got CD GPIO\n");
+		else if (ret != -ENOENT)
+			return ret;
+
+		/*
+		 * There are two ways to flag that the CD line is inverted:
+		 * through the cd-inverted flag and by the GPIO line itself
+		 * being inverted from the GPIO subsystem. This is a leftover
+		 * from the times when the GPIO subsystem did not make it
+		 * possible to flag a line as inverted.
+		 *
+		 * If the capability on the host AND the GPIO line are
+		 * both inverted, the end result is that the CD line is
+		 * not inverted.
+		 */
+		if (cd_cap_invert ^ cd_gpio_invert)
+			host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
+	}
+
+	/* Parse Write Protection */
+	ro_cap_invert = of_property_read_bool(np, "wp-inverted");
+
+	ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
+	if (!ret)
+		dev_info(host->parent, "Got WP GPIO\n");
+	else if (ret != -ENOENT)
+		return ret;
+
+	/* See the comment on CD inversion above */
+	if (ro_cap_invert ^ ro_gpio_invert)
+		host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
+
+	if (of_find_property(np, "cap-sd-highspeed", &len))
+		host->caps |= MMC_CAP_SD_HIGHSPEED;
+	if (of_find_property(np, "cap-mmc-highspeed", &len))
+		host->caps |= MMC_CAP_MMC_HIGHSPEED;
+	if (of_find_property(np, "sd-uhs-sdr12", &len))
+		host->caps |= MMC_CAP_UHS_SDR12;
+	if (of_find_property(np, "sd-uhs-sdr25", &len))
+		host->caps |= MMC_CAP_UHS_SDR25;
+	if (of_find_property(np, "sd-uhs-sdr50", &len))
+		host->caps |= MMC_CAP_UHS_SDR50;
+	if (of_find_property(np, "sd-uhs-sdr104", &len))
+		host->caps |= MMC_CAP_UHS_SDR104;
+	if (of_find_property(np, "sd-uhs-ddr50", &len))
+		host->caps |= MMC_CAP_UHS_DDR50;
+	if (of_find_property(np, "cap-power-off-card", &len))
+		host->caps |= MMC_CAP_POWER_OFF_CARD;
+	if (of_find_property(np, "cap-sdio-irq", &len))
+		host->caps |= MMC_CAP_SDIO_IRQ;
+	if (of_find_property(np, "full-pwr-cycle", &len))
+		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
+	if (of_find_property(np, "keep-power-in-suspend", &len))
+		host->pm_caps |= MMC_PM_KEEP_POWER;
+	if (of_find_property(np, "enable-sdio-wakeup", &len))
+		host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
+	if (of_find_property(np, "mmc-ddr-1_8v", &len))
+		host->caps |= MMC_CAP_1_8V_DDR;
+	if (of_find_property(np, "mmc-ddr-1_2v", &len))
+		host->caps |= MMC_CAP_1_2V_DDR;
+	if (of_find_property(np, "mmc-hs200-1_8v", &len))
+		host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
+	if (of_find_property(np, "mmc-hs200-1_2v", &len))
+		host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
+	if (of_find_property(np, "mmc-hs400-1_8v", &len))
+		host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
+	if (of_find_property(np, "mmc-hs400-1_2v", &len))
+		host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
+
+	host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
+	if (host->dsr_req && (host->dsr & ~0xffff)) {
+		dev_err(host->parent,
+			"device tree specified broken value for DSR: 0x%x, ignoring\n",
+			host->dsr);
+		host->dsr_req = 0;
+	}
+
+	return mmc_pwrseq_alloc(host);
+}
+
+EXPORT_SYMBOL(mmc_of_parse);
+
+/**
+ *	mmc_alloc_host - initialise the per-host structure.
+ *	@extra: sizeof private data structure
+ *	@dev: pointer to host device model structure
+ *
+ *	Initialise the per-host structure.
+ */
+struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
+{
+	int err;
+	struct mmc_host *host;
+
+	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
+	if (!host)
+		return NULL;
+
+	/* scanning will be enabled when we're ready */
+	host->rescan_disable = 1;
+	idr_preload(GFP_KERNEL);
+	spin_lock(&mmc_host_lock);
+	err = idr_alloc(&mmc_host_idr, host, 0, 0, GFP_NOWAIT);
+	if (err >= 0)
+		host->index = err;
+	spin_unlock(&mmc_host_lock);
+	idr_preload_end();
+	if (err < 0) {
+		kfree(host);
+		return NULL;
+	}
+
+	dev_set_name(&host->class_dev, "mmc%d", host->index);
+
+	host->parent = dev;
+	host->class_dev.parent = dev;
+	host->class_dev.class = &mmc_host_class;
+	device_initialize(&host->class_dev);
+
+	if (mmc_gpio_alloc(host)) {
+		put_device(&host->class_dev);
+		return NULL;
+	}
+
+	mmc_host_clk_init(host);
+
+	spin_lock_init(&host->lock);
+	init_waitqueue_head(&host->wq);
+	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
+#ifdef CONFIG_PM
+	host->pm_notify.notifier_call = mmc_pm_notify;
+#endif
+
+	/*
+	 * By default, hosts do not support SGIO or large requests.
+	 * They have to set these according to their abilities.
+	 */
+	host->max_segs = 1;
+	host->max_seg_size = PAGE_CACHE_SIZE;
+
+	host->max_req_size = PAGE_CACHE_SIZE;
+	host->max_blk_size = 512;
+	host->max_blk_count = PAGE_CACHE_SIZE / 512;
+
+	return host;
+}
+
+EXPORT_SYMBOL(mmc_alloc_host);
+
+/**
+ *	mmc_add_host - initialise host hardware
+ *	@host: mmc host
+ *
+ *	Register the host with the driver model. The host must be
+ *	prepared to start servicing requests before this function
+ *	completes.
+ */
+int mmc_add_host(struct mmc_host *host)
+{
+	int err;
+
+	WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
+		!host->ops->enable_sdio_irq);
+
+	err = device_add(&host->class_dev);
+	if (err)
+		return err;
+
+	led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
+
+#ifdef CONFIG_DEBUG_FS
+	mmc_add_host_debugfs(host);
+#endif
+	mmc_host_clk_sysfs_init(host);
+
+	mmc_start_host(host);
+	register_pm_notifier(&host->pm_notify);
+
+	return 0;
+}
+
+EXPORT_SYMBOL(mmc_add_host);
+
+/**
+ *	mmc_remove_host - remove host hardware
+ *	@host: mmc host
+ *
+ *	Unregister and remove all cards associated with this host,
+ *	and power down the MMC bus. No new requests will be issued
+ *	after this function has returned.
+ */
+void mmc_remove_host(struct mmc_host *host)
+{
+	unregister_pm_notifier(&host->pm_notify);
+	mmc_stop_host(host);
+
+#ifdef CONFIG_DEBUG_FS
+	mmc_remove_host_debugfs(host);
+#endif
+
+	device_del(&host->class_dev);
+
+	led_trigger_unregister_simple(host->led);
+
+	mmc_host_clk_exit(host);
+}
+
+EXPORT_SYMBOL(mmc_remove_host);
+
+/**
+ *	mmc_free_host - free the host structure
+ *	@host: mmc host
+ *
+ *	Free the host once all references to it have been dropped.
+ */
+void mmc_free_host(struct mmc_host *host)
+{
+	mmc_pwrseq_free(host);
+	put_device(&host->class_dev);
+}
+
+EXPORT_SYMBOL(mmc_free_host);