diff options
Diffstat (limited to 'drivers/dma/qcom/hidma_ll.c')
| -rw-r--r-- | drivers/dma/qcom/hidma_ll.c | 872 |
1 files changed, 872 insertions, 0 deletions
diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c new file mode 100644 index 000000000..f39290015 --- /dev/null +++ b/drivers/dma/qcom/hidma_ll.c @@ -0,0 +1,872 @@ +/* + * Qualcomm Technologies HIDMA DMA engine low level code + * + * Copyright (c) 2015-2016, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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. + */ + +#include <linux/dmaengine.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/mm.h> +#include <linux/highmem.h> +#include <linux/dma-mapping.h> +#include <linux/delay.h> +#include <linux/atomic.h> +#include <linux/iopoll.h> +#include <linux/kfifo.h> +#include <linux/bitops.h> + +#include "hidma.h" + +#define HIDMA_EVRE_SIZE 16 /* each EVRE is 16 bytes */ + +#define HIDMA_TRCA_CTRLSTS_REG 0x000 +#define HIDMA_TRCA_RING_LOW_REG 0x008 +#define HIDMA_TRCA_RING_HIGH_REG 0x00C +#define HIDMA_TRCA_RING_LEN_REG 0x010 +#define HIDMA_TRCA_DOORBELL_REG 0x400 + +#define HIDMA_EVCA_CTRLSTS_REG 0x000 +#define HIDMA_EVCA_INTCTRL_REG 0x004 +#define HIDMA_EVCA_RING_LOW_REG 0x008 +#define HIDMA_EVCA_RING_HIGH_REG 0x00C +#define HIDMA_EVCA_RING_LEN_REG 0x010 +#define HIDMA_EVCA_WRITE_PTR_REG 0x020 +#define HIDMA_EVCA_DOORBELL_REG 0x400 + +#define HIDMA_EVCA_IRQ_STAT_REG 0x100 +#define HIDMA_EVCA_IRQ_CLR_REG 0x108 +#define HIDMA_EVCA_IRQ_EN_REG 0x110 + +#define HIDMA_EVRE_CFG_IDX 0 + +#define HIDMA_EVRE_ERRINFO_BIT_POS 24 +#define HIDMA_EVRE_CODE_BIT_POS 28 + +#define HIDMA_EVRE_ERRINFO_MASK GENMASK(3, 0) +#define HIDMA_EVRE_CODE_MASK GENMASK(3, 0) + +#define HIDMA_CH_CONTROL_MASK GENMASK(7, 0) +#define HIDMA_CH_STATE_MASK GENMASK(7, 0) +#define HIDMA_CH_STATE_BIT_POS 0x8 + +#define HIDMA_IRQ_EV_CH_EOB_IRQ_BIT_POS 0 +#define HIDMA_IRQ_EV_CH_WR_RESP_BIT_POS 1 +#define HIDMA_IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS 9 +#define HIDMA_IRQ_TR_CH_DATA_RD_ER_BIT_POS 10 +#define HIDMA_IRQ_TR_CH_DATA_WR_ER_BIT_POS 11 +#define HIDMA_IRQ_TR_CH_INVALID_TRE_BIT_POS 14 + +#define ENABLE_IRQS (BIT(HIDMA_IRQ_EV_CH_EOB_IRQ_BIT_POS) | \ + BIT(HIDMA_IRQ_EV_CH_WR_RESP_BIT_POS) | \ + BIT(HIDMA_IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS) | \ + BIT(HIDMA_IRQ_TR_CH_DATA_RD_ER_BIT_POS) | \ + BIT(HIDMA_IRQ_TR_CH_DATA_WR_ER_BIT_POS) | \ + BIT(HIDMA_IRQ_TR_CH_INVALID_TRE_BIT_POS)) + +#define HIDMA_INCREMENT_ITERATOR(iter, size, ring_size) \ +do { \ + iter += size; \ + if (iter >= ring_size) \ + iter -= ring_size; \ +} while (0) + +#define HIDMA_CH_STATE(val) \ + ((val >> HIDMA_CH_STATE_BIT_POS) & HIDMA_CH_STATE_MASK) + +#define HIDMA_ERR_INT_MASK \ + (BIT(HIDMA_IRQ_TR_CH_INVALID_TRE_BIT_POS) | \ + BIT(HIDMA_IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS) | \ + BIT(HIDMA_IRQ_EV_CH_WR_RESP_BIT_POS) | \ + BIT(HIDMA_IRQ_TR_CH_DATA_RD_ER_BIT_POS) | \ + BIT(HIDMA_IRQ_TR_CH_DATA_WR_ER_BIT_POS)) + +enum ch_command { + HIDMA_CH_DISABLE = 0, + HIDMA_CH_ENABLE = 1, + HIDMA_CH_SUSPEND = 2, + HIDMA_CH_RESET = 9, +}; + +enum ch_state { + HIDMA_CH_DISABLED = 0, + HIDMA_CH_ENABLED = 1, + HIDMA_CH_RUNNING = 2, + HIDMA_CH_SUSPENDED = 3, + HIDMA_CH_STOPPED = 4, +}; + +enum tre_type { + HIDMA_TRE_MEMCPY = 3, +}; + +enum err_code { + HIDMA_EVRE_STATUS_COMPLETE = 1, + HIDMA_EVRE_STATUS_ERROR = 4, +}; + +static int hidma_is_chan_enabled(int state) +{ + switch (state) { + case HIDMA_CH_ENABLED: + case HIDMA_CH_RUNNING: + return true; + default: + return false; + } +} + +void hidma_ll_free(struct hidma_lldev *lldev, u32 tre_ch) +{ + struct hidma_tre *tre; + + if (tre_ch >= lldev->nr_tres) { + dev_err(lldev->dev, "invalid TRE number in free:%d", tre_ch); + return; + } + + tre = &lldev->trepool[tre_ch]; + if (atomic_read(&tre->allocated) != true) { + dev_err(lldev->dev, "trying to free an unused TRE:%d", tre_ch); + return; + } + + atomic_set(&tre->allocated, 0); +} + +int hidma_ll_request(struct hidma_lldev *lldev, u32 sig, const char *dev_name, + void (*callback)(void *data), void *data, u32 *tre_ch) +{ + unsigned int i; + struct hidma_tre *tre; + u32 *tre_local; + + if (!tre_ch || !lldev) + return -EINVAL; + + /* need to have at least one empty spot in the queue */ + for (i = 0; i < lldev->nr_tres - 1; i++) { + if (atomic_add_unless(&lldev->trepool[i].allocated, 1, 1)) + break; + } + + if (i == (lldev->nr_tres - 1)) + return -ENOMEM; + + tre = &lldev->trepool[i]; + tre->dma_sig = sig; + tre->dev_name = dev_name; + tre->callback = callback; + tre->data = data; + tre->idx = i; + tre->status = 0; + tre->queued = 0; + tre->err_code = 0; + tre->err_info = 0; + tre->lldev = lldev; + tre_local = &tre->tre_local[0]; + tre_local[HIDMA_TRE_CFG_IDX] = HIDMA_TRE_MEMCPY; + tre_local[HIDMA_TRE_CFG_IDX] |= (lldev->chidx & 0xFF) << 8; + tre_local[HIDMA_TRE_CFG_IDX] |= BIT(16); /* set IEOB */ + *tre_ch = i; + if (callback) + callback(data); + return 0; +} + +/* + * Multiple TREs may be queued and waiting in the pending queue. + */ +static void hidma_ll_tre_complete(unsigned long arg) +{ + struct hidma_lldev *lldev = (struct hidma_lldev *)arg; + struct hidma_tre *tre; + + while (kfifo_out(&lldev->handoff_fifo, &tre, 1)) { + /* call the user if it has been read by the hardware */ + if (tre->callback) + tre->callback(tre->data); + } +} + +static int hidma_post_completed(struct hidma_lldev *lldev, int tre_iterator, + u8 err_info, u8 err_code) +{ + struct hidma_tre *tre; + unsigned long flags; + + spin_lock_irqsave(&lldev->lock, flags); + tre = lldev->pending_tre_list[tre_iterator / HIDMA_TRE_SIZE]; + if (!tre) { + spin_unlock_irqrestore(&lldev->lock, flags); + dev_warn(lldev->dev, "tre_index [%d] and tre out of sync\n", + tre_iterator / HIDMA_TRE_SIZE); + return -EINVAL; + } + lldev->pending_tre_list[tre->tre_index] = NULL; + + /* + * Keep track of pending TREs that SW is expecting to receive + * from HW. We got one now. Decrement our counter. + */ + lldev->pending_tre_count--; + if (lldev->pending_tre_count < 0) { + dev_warn(lldev->dev, "tre count mismatch on completion"); + lldev->pending_tre_count = 0; + } + + spin_unlock_irqrestore(&lldev->lock, flags); + + tre->err_info = err_info; + tre->err_code = err_code; + tre->queued = 0; + + kfifo_put(&lldev->handoff_fifo, tre); + tasklet_schedule(&lldev->task); + + return 0; +} + +/* + * Called to handle the interrupt for the channel. + * Return a positive number if TRE or EVRE were consumed on this run. + * Return a positive number if there are pending TREs or EVREs. + * Return 0 if there is nothing to consume or no pending TREs/EVREs found. + */ +static int hidma_handle_tre_completion(struct hidma_lldev *lldev) +{ + u32 evre_ring_size = lldev->evre_ring_size; + u32 tre_ring_size = lldev->tre_ring_size; + u32 err_info, err_code, evre_write_off; + u32 tre_iterator, evre_iterator; + u32 num_completed = 0; + + evre_write_off = readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG); + tre_iterator = lldev->tre_processed_off; + evre_iterator = lldev->evre_processed_off; + + if ((evre_write_off > evre_ring_size) || + (evre_write_off % HIDMA_EVRE_SIZE)) { + dev_err(lldev->dev, "HW reports invalid EVRE write offset\n"); + return 0; + } + + /* + * By the time control reaches here the number of EVREs and TREs + * may not match. Only consume the ones that hardware told us. + */ + while ((evre_iterator != evre_write_off)) { + u32 *current_evre = lldev->evre_ring + evre_iterator; + u32 cfg; + + cfg = current_evre[HIDMA_EVRE_CFG_IDX]; + err_info = cfg >> HIDMA_EVRE_ERRINFO_BIT_POS; + err_info &= HIDMA_EVRE_ERRINFO_MASK; + err_code = + (cfg >> HIDMA_EVRE_CODE_BIT_POS) & HIDMA_EVRE_CODE_MASK; + + if (hidma_post_completed(lldev, tre_iterator, err_info, + err_code)) + break; + + HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE, + tre_ring_size); + HIDMA_INCREMENT_ITERATOR(evre_iterator, HIDMA_EVRE_SIZE, + evre_ring_size); + + /* + * Read the new event descriptor written by the HW. + * As we are processing the delivered events, other events + * get queued to the SW for processing. + */ + evre_write_off = + readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG); + num_completed++; + } + + if (num_completed) { + u32 evre_read_off = (lldev->evre_processed_off + + HIDMA_EVRE_SIZE * num_completed); + u32 tre_read_off = (lldev->tre_processed_off + + HIDMA_TRE_SIZE * num_completed); + + evre_read_off = evre_read_off % evre_ring_size; + tre_read_off = tre_read_off % tre_ring_size; + + writel(evre_read_off, lldev->evca + HIDMA_EVCA_DOORBELL_REG); + + /* record the last processed tre offset */ + lldev->tre_processed_off = tre_read_off; + lldev->evre_processed_off = evre_read_off; + } + + return num_completed; +} + +void hidma_cleanup_pending_tre(struct hidma_lldev *lldev, u8 err_info, + u8 err_code) +{ + u32 tre_iterator; + u32 tre_ring_size = lldev->tre_ring_size; + int num_completed = 0; + u32 tre_read_off; + + tre_iterator = lldev->tre_processed_off; + while (lldev->pending_tre_count) { + if (hidma_post_completed(lldev, tre_iterator, err_info, + err_code)) + break; + HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE, + tre_ring_size); + num_completed++; + } + tre_read_off = (lldev->tre_processed_off + + HIDMA_TRE_SIZE * num_completed); + + tre_read_off = tre_read_off % tre_ring_size; + + /* record the last processed tre offset */ + lldev->tre_processed_off = tre_read_off; +} + +static int hidma_ll_reset(struct hidma_lldev *lldev) +{ + u32 val; + int ret; + + val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG); + val &= ~(HIDMA_CH_CONTROL_MASK << 16); + val |= HIDMA_CH_RESET << 16; + writel(val, lldev->trca + HIDMA_TRCA_CTRLSTS_REG); + + /* + * Delay 10ms after reset to allow DMA logic to quiesce. + * Do a polled read up to 1ms and 10ms maximum. + */ + ret = readl_poll_timeout(lldev->trca + HIDMA_TRCA_CTRLSTS_REG, val, + HIDMA_CH_STATE(val) == HIDMA_CH_DISABLED, + 1000, 10000); + if (ret) { + dev_err(lldev->dev, "transfer channel did not reset\n"); + return ret; + } + + val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG); + val &= ~(HIDMA_CH_CONTROL_MASK << 16); + val |= HIDMA_CH_RESET << 16; + writel(val, lldev->evca + HIDMA_EVCA_CTRLSTS_REG); + + /* + * Delay 10ms after reset to allow DMA logic to quiesce. + * Do a polled read up to 1ms and 10ms maximum. + */ + ret = readl_poll_timeout(lldev->evca + HIDMA_EVCA_CTRLSTS_REG, val, + HIDMA_CH_STATE(val) == HIDMA_CH_DISABLED, + 1000, 10000); + if (ret) + return ret; + + lldev->trch_state = HIDMA_CH_DISABLED; + lldev->evch_state = HIDMA_CH_DISABLED; + return 0; +} + +/* + * Abort all transactions and perform a reset. + */ +static void hidma_ll_abort(unsigned long arg) +{ + struct hidma_lldev *lldev = (struct hidma_lldev *)arg; + u8 err_code = HIDMA_EVRE_STATUS_ERROR; + u8 err_info = 0xFF; + int rc; + + hidma_cleanup_pending_tre(lldev, err_info, err_code); + + /* reset the channel for recovery */ + rc = hidma_ll_setup(lldev); + if (rc) { + dev_err(lldev->dev, "channel reinitialize failed after error\n"); + return; + } + writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG); +} + +/* + * The interrupt handler for HIDMA will try to consume as many pending + * EVRE from the event queue as possible. Each EVRE has an associated + * TRE that holds the user interface parameters. EVRE reports the + * result of the transaction. Hardware guarantees ordering between EVREs + * and TREs. We use last processed offset to figure out which TRE is + * associated with which EVRE. If two TREs are consumed by HW, the EVREs + * are in order in the event ring. + * + * This handler will do a one pass for consuming EVREs. Other EVREs may + * be delivered while we are working. It will try to consume incoming + * EVREs one more time and return. + * + * For unprocessed EVREs, hardware will trigger another interrupt until + * all the interrupt bits are cleared. + * + * Hardware guarantees that by the time interrupt is observed, all data + * transactions in flight are delivered to their respective places and + * are visible to the CPU. + * + * On demand paging for IOMMU is only supported for PCIe via PRI + * (Page Request Interface) not for HIDMA. All other hardware instances + * including HIDMA work on pinned DMA addresses. + * + * HIDMA is not aware of IOMMU presence since it follows the DMA API. All + * IOMMU latency will be built into the data movement time. By the time + * interrupt happens, IOMMU lookups + data movement has already taken place. + * + * While the first read in a typical PCI endpoint ISR flushes all outstanding + * requests traditionally to the destination, this concept does not apply + * here for this HW. + */ +irqreturn_t hidma_ll_inthandler(int chirq, void *arg) +{ + struct hidma_lldev *lldev = arg; + u32 status; + u32 enable; + u32 cause; + + /* + * Fine tuned for this HW... + * + * This ISR has been designed for this particular hardware. Relaxed + * read and write accessors are used for performance reasons due to + * interrupt delivery guarantees. Do not copy this code blindly and + * expect that to work. + */ + status = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG); + enable = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_EN_REG); + cause = status & enable; + + while (cause) { + if (cause & HIDMA_ERR_INT_MASK) { + dev_err(lldev->dev, "error 0x%x, resetting...\n", + cause); + + /* Clear out pending interrupts */ + writel(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG); + + tasklet_schedule(&lldev->rst_task); + goto out; + } + + /* + * Try to consume as many EVREs as possible. + */ + hidma_handle_tre_completion(lldev); + + /* We consumed TREs or there are pending TREs or EVREs. */ + writel_relaxed(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG); + + /* + * Another interrupt might have arrived while we are + * processing this one. Read the new cause. + */ + status = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG); + enable = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_EN_REG); + cause = status & enable; + } + +out: + return IRQ_HANDLED; +} + +int hidma_ll_enable(struct hidma_lldev *lldev) +{ + u32 val; + int ret; + + val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG); + val &= ~(HIDMA_CH_CONTROL_MASK << 16); + val |= HIDMA_CH_ENABLE << 16; + writel(val, lldev->evca + HIDMA_EVCA_CTRLSTS_REG); + + ret = readl_poll_timeout(lldev->evca + HIDMA_EVCA_CTRLSTS_REG, val, + hidma_is_chan_enabled(HIDMA_CH_STATE(val)), + 1000, 10000); + if (ret) { + dev_err(lldev->dev, "event channel did not get enabled\n"); + return ret; + } + + val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG); + val &= ~(HIDMA_CH_CONTROL_MASK << 16); + val |= HIDMA_CH_ENABLE << 16; + writel(val, lldev->trca + HIDMA_TRCA_CTRLSTS_REG); + + ret = readl_poll_timeout(lldev->trca + HIDMA_TRCA_CTRLSTS_REG, val, + hidma_is_chan_enabled(HIDMA_CH_STATE(val)), + 1000, 10000); + if (ret) { + dev_err(lldev->dev, "transfer channel did not get enabled\n"); + return ret; + } + + lldev->trch_state = HIDMA_CH_ENABLED; + lldev->evch_state = HIDMA_CH_ENABLED; + + return 0; +} + +void hidma_ll_start(struct hidma_lldev *lldev) +{ + unsigned long irqflags; + + spin_lock_irqsave(&lldev->lock, irqflags); + writel(lldev->tre_write_offset, lldev->trca + HIDMA_TRCA_DOORBELL_REG); + spin_unlock_irqrestore(&lldev->lock, irqflags); +} + +bool hidma_ll_isenabled(struct hidma_lldev *lldev) +{ + u32 val; + + val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG); + lldev->trch_state = HIDMA_CH_STATE(val); + val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG); + lldev->evch_state = HIDMA_CH_STATE(val); + + /* both channels have to be enabled before calling this function */ + if (hidma_is_chan_enabled(lldev->trch_state) && + hidma_is_chan_enabled(lldev->evch_state)) + return true; + + return false; +} + +void hidma_ll_queue_request(struct hidma_lldev *lldev, u32 tre_ch) +{ + struct hidma_tre *tre; + unsigned long flags; + + tre = &lldev->trepool[tre_ch]; + + /* copy the TRE into its location in the TRE ring */ + spin_lock_irqsave(&lldev->lock, flags); + tre->tre_index = lldev->tre_write_offset / HIDMA_TRE_SIZE; + lldev->pending_tre_list[tre->tre_index] = tre; + memcpy(lldev->tre_ring + lldev->tre_write_offset, + &tre->tre_local[0], HIDMA_TRE_SIZE); + tre->err_code = 0; + tre->err_info = 0; + tre->queued = 1; + lldev->pending_tre_count++; + lldev->tre_write_offset = (lldev->tre_write_offset + HIDMA_TRE_SIZE) + % lldev->tre_ring_size; + spin_unlock_irqrestore(&lldev->lock, flags); +} + +/* + * Note that even though we stop this channel if there is a pending transaction + * in flight it will complete and follow the callback. This request will + * prevent further requests to be made. + */ +int hidma_ll_disable(struct hidma_lldev *lldev) +{ + u32 val; + int ret; + + val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG); + lldev->evch_state = HIDMA_CH_STATE(val); + val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG); + lldev->trch_state = HIDMA_CH_STATE(val); + + /* already suspended by this OS */ + if ((lldev->trch_state == HIDMA_CH_SUSPENDED) || + (lldev->evch_state == HIDMA_CH_SUSPENDED)) + return 0; + + /* already stopped by the manager */ + if ((lldev->trch_state == HIDMA_CH_STOPPED) || + (lldev->evch_state == HIDMA_CH_STOPPED)) + return 0; + + val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG); + val &= ~(HIDMA_CH_CONTROL_MASK << 16); + val |= HIDMA_CH_SUSPEND << 16; + writel(val, lldev->trca + HIDMA_TRCA_CTRLSTS_REG); + + /* + * Start the wait right after the suspend is confirmed. + * Do a polled read up to 1ms and 10ms maximum. + */ + ret = readl_poll_timeout(lldev->trca + HIDMA_TRCA_CTRLSTS_REG, val, + HIDMA_CH_STATE(val) == HIDMA_CH_SUSPENDED, + 1000, 10000); + if (ret) + return ret; + + val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG); + val &= ~(HIDMA_CH_CONTROL_MASK << 16); + val |= HIDMA_CH_SUSPEND << 16; + writel(val, lldev->evca + HIDMA_EVCA_CTRLSTS_REG); + + /* + * Start the wait right after the suspend is confirmed + * Delay up to 10ms after reset to allow DMA logic to quiesce. + */ + ret = readl_poll_timeout(lldev->evca + HIDMA_EVCA_CTRLSTS_REG, val, + HIDMA_CH_STATE(val) == HIDMA_CH_SUSPENDED, + 1000, 10000); + if (ret) + return ret; + + lldev->trch_state = HIDMA_CH_SUSPENDED; + lldev->evch_state = HIDMA_CH_SUSPENDED; + return 0; +} + +void hidma_ll_set_transfer_params(struct hidma_lldev *lldev, u32 tre_ch, + dma_addr_t src, dma_addr_t dest, u32 len, + u32 flags) +{ + struct hidma_tre *tre; + u32 *tre_local; + + if (tre_ch >= lldev->nr_tres) { + dev_err(lldev->dev, "invalid TRE number in transfer params:%d", + tre_ch); + return; + } + + tre = &lldev->trepool[tre_ch]; + if (atomic_read(&tre->allocated) != true) { + dev_err(lldev->dev, "trying to set params on an unused TRE:%d", + tre_ch); + return; + } + + tre_local = &tre->tre_local[0]; + tre_local[HIDMA_TRE_LEN_IDX] = len; + tre_local[HIDMA_TRE_SRC_LOW_IDX] = lower_32_bits(src); + tre_local[HIDMA_TRE_SRC_HI_IDX] = upper_32_bits(src); + tre_local[HIDMA_TRE_DEST_LOW_IDX] = lower_32_bits(dest); + tre_local[HIDMA_TRE_DEST_HI_IDX] = upper_32_bits(dest); + tre->int_flags = flags; +} + +/* + * Called during initialization and after an error condition + * to restore hardware state. + */ +int hidma_ll_setup(struct hidma_lldev *lldev) +{ + int rc; + u64 addr; + u32 val; + u32 nr_tres = lldev->nr_tres; + + lldev->pending_tre_count = 0; + lldev->tre_processed_off = 0; + lldev->evre_processed_off = 0; + lldev->tre_write_offset = 0; + + /* disable interrupts */ + writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG); + + /* clear all pending interrupts */ + val = readl(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG); + writel(val, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG); + + rc = hidma_ll_reset(lldev); + if (rc) + return rc; + + /* + * Clear all pending interrupts again. + * Otherwise, we observe reset complete interrupts. + */ + val = readl(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG); + writel(val, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG); + + /* disable interrupts again after reset */ + writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG); + + addr = lldev->tre_dma; + writel(lower_32_bits(addr), lldev->trca + HIDMA_TRCA_RING_LOW_REG); + writel(upper_32_bits(addr), lldev->trca + HIDMA_TRCA_RING_HIGH_REG); + writel(lldev->tre_ring_size, lldev->trca + HIDMA_TRCA_RING_LEN_REG); + + addr = lldev->evre_dma; + writel(lower_32_bits(addr), lldev->evca + HIDMA_EVCA_RING_LOW_REG); + writel(upper_32_bits(addr), lldev->evca + HIDMA_EVCA_RING_HIGH_REG); + writel(HIDMA_EVRE_SIZE * nr_tres, + lldev->evca + HIDMA_EVCA_RING_LEN_REG); + + /* support IRQ only for now */ + val = readl(lldev->evca + HIDMA_EVCA_INTCTRL_REG); + val &= ~0xF; + val |= 0x1; + writel(val, lldev->evca + HIDMA_EVCA_INTCTRL_REG); + + /* clear all pending interrupts and enable them */ + writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG); + writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG); + + return hidma_ll_enable(lldev); +} + +struct hidma_lldev *hidma_ll_init(struct device *dev, u32 nr_tres, + void __iomem *trca, void __iomem *evca, + u8 chidx) +{ + u32 required_bytes; + struct hidma_lldev *lldev; + int rc; + size_t sz; + + if (!trca || !evca || !dev || !nr_tres) + return NULL; + + /* need at least four TREs */ + if (nr_tres < 4) + return NULL; + + /* need an extra space */ + nr_tres += 1; + + lldev = devm_kzalloc(dev, sizeof(struct hidma_lldev), GFP_KERNEL); + if (!lldev) + return NULL; + + lldev->evca = evca; + lldev->trca = trca; + lldev->dev = dev; + sz = sizeof(struct hidma_tre); + lldev->trepool = devm_kcalloc(lldev->dev, nr_tres, sz, GFP_KERNEL); + if (!lldev->trepool) + return NULL; + + required_bytes = sizeof(lldev->pending_tre_list[0]); + lldev->pending_tre_list = devm_kcalloc(dev, nr_tres, required_bytes, + GFP_KERNEL); + if (!lldev->pending_tre_list) + return NULL; + + sz = (HIDMA_TRE_SIZE + 1) * nr_tres; + lldev->tre_ring = dmam_alloc_coherent(dev, sz, &lldev->tre_dma, + GFP_KERNEL); + if (!lldev->tre_ring) + return NULL; + + memset(lldev->tre_ring, 0, (HIDMA_TRE_SIZE + 1) * nr_tres); + lldev->tre_ring_size = HIDMA_TRE_SIZE * nr_tres; + lldev->nr_tres = nr_tres; + + /* the TRE ring has to be TRE_SIZE aligned */ + if (!IS_ALIGNED(lldev->tre_dma, HIDMA_TRE_SIZE)) { + u8 tre_ring_shift; + + tre_ring_shift = lldev->tre_dma % HIDMA_TRE_SIZE; + tre_ring_shift = HIDMA_TRE_SIZE - tre_ring_shift; + lldev->tre_dma += tre_ring_shift; + lldev->tre_ring += tre_ring_shift; + } + + sz = (HIDMA_EVRE_SIZE + 1) * nr_tres; + lldev->evre_ring = dmam_alloc_coherent(dev, sz, &lldev->evre_dma, + GFP_KERNEL); + if (!lldev->evre_ring) + return NULL; + + memset(lldev->evre_ring, 0, (HIDMA_EVRE_SIZE + 1) * nr_tres); + lldev->evre_ring_size = HIDMA_EVRE_SIZE * nr_tres; + + /* the EVRE ring has to be EVRE_SIZE aligned */ + if (!IS_ALIGNED(lldev->evre_dma, HIDMA_EVRE_SIZE)) { + u8 evre_ring_shift; + + evre_ring_shift = lldev->evre_dma % HIDMA_EVRE_SIZE; + evre_ring_shift = HIDMA_EVRE_SIZE - evre_ring_shift; + lldev->evre_dma += evre_ring_shift; + lldev->evre_ring += evre_ring_shift; + } + lldev->nr_tres = nr_tres; + lldev->chidx = chidx; + + sz = nr_tres * sizeof(struct hidma_tre *); + rc = kfifo_alloc(&lldev->handoff_fifo, sz, GFP_KERNEL); + if (rc) + return NULL; + + rc = hidma_ll_setup(lldev); + if (rc) + return NULL; + + spin_lock_init(&lldev->lock); + tasklet_init(&lldev->rst_task, hidma_ll_abort, (unsigned long)lldev); + tasklet_init(&lldev->task, hidma_ll_tre_complete, (unsigned long)lldev); + lldev->initialized = 1; + writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG); + return lldev; +} + +int hidma_ll_uninit(struct hidma_lldev *lldev) +{ + u32 required_bytes; + int rc = 0; + u32 val; + + if (!lldev) + return -ENODEV; + + if (!lldev->initialized) + return 0; + + lldev->initialized = 0; + + required_bytes = sizeof(struct hidma_tre) * lldev->nr_tres; + tasklet_kill(&lldev->task); + memset(lldev->trepool, 0, required_bytes); + lldev->trepool = NULL; + lldev->pending_tre_count = 0; + lldev->tre_write_offset = 0; + + rc = hidma_ll_reset(lldev); + + /* + * Clear all pending interrupts again. + * Otherwise, we observe reset complete interrupts. + */ + val = readl(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG); + writel(val, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG); + writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG); + return rc; +} + +enum dma_status hidma_ll_status(struct hidma_lldev *lldev, u32 tre_ch) +{ + enum dma_status ret = DMA_ERROR; + struct hidma_tre *tre; + unsigned long flags; + u8 err_code; + + spin_lock_irqsave(&lldev->lock, flags); + + tre = &lldev->trepool[tre_ch]; + err_code = tre->err_code; + + if (err_code & HIDMA_EVRE_STATUS_COMPLETE) + ret = DMA_COMPLETE; + else if (err_code & HIDMA_EVRE_STATUS_ERROR) + ret = DMA_ERROR; + else + ret = DMA_IN_PROGRESS; + spin_unlock_irqrestore(&lldev->lock, flags); + + return ret; +} |