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-rw-r--r--drivers/dma/fsldma.c1547
1 files changed, 1547 insertions, 0 deletions
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
new file mode 100644
index 000000000..300f821f1
--- /dev/null
+++ b/drivers/dma/fsldma.c
@@ -0,0 +1,1547 @@
+/*
+ * Freescale MPC85xx, MPC83xx DMA Engine support
+ *
+ * Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * Author:
+ * Zhang Wei <wei.zhang@freescale.com>, Jul 2007
+ * Ebony Zhu <ebony.zhu@freescale.com>, May 2007
+ *
+ * Description:
+ * DMA engine driver for Freescale MPC8540 DMA controller, which is
+ * also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc.
+ * The support for MPC8349 DMA controller is also added.
+ *
+ * This driver instructs the DMA controller to issue the PCI Read Multiple
+ * command for PCI read operations, instead of using the default PCI Read Line
+ * command. Please be aware that this setting may result in read pre-fetching
+ * on some platforms.
+ *
+ * This 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.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/fsldma.h>
+#include "dmaengine.h"
+#include "fsldma.h"
+
+#define chan_dbg(chan, fmt, arg...) \
+ dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
+#define chan_err(chan, fmt, arg...) \
+ dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
+
+static const char msg_ld_oom[] = "No free memory for link descriptor";
+
+/*
+ * Register Helpers
+ */
+
+static void set_sr(struct fsldma_chan *chan, u32 val)
+{
+ DMA_OUT(chan, &chan->regs->sr, val, 32);
+}
+
+static u32 get_sr(struct fsldma_chan *chan)
+{
+ return DMA_IN(chan, &chan->regs->sr, 32);
+}
+
+static void set_mr(struct fsldma_chan *chan, u32 val)
+{
+ DMA_OUT(chan, &chan->regs->mr, val, 32);
+}
+
+static u32 get_mr(struct fsldma_chan *chan)
+{
+ return DMA_IN(chan, &chan->regs->mr, 32);
+}
+
+static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
+{
+ DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
+}
+
+static dma_addr_t get_cdar(struct fsldma_chan *chan)
+{
+ return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
+}
+
+static void set_bcr(struct fsldma_chan *chan, u32 val)
+{
+ DMA_OUT(chan, &chan->regs->bcr, val, 32);
+}
+
+static u32 get_bcr(struct fsldma_chan *chan)
+{
+ return DMA_IN(chan, &chan->regs->bcr, 32);
+}
+
+/*
+ * Descriptor Helpers
+ */
+
+static void set_desc_cnt(struct fsldma_chan *chan,
+ struct fsl_dma_ld_hw *hw, u32 count)
+{
+ hw->count = CPU_TO_DMA(chan, count, 32);
+}
+
+static void set_desc_src(struct fsldma_chan *chan,
+ struct fsl_dma_ld_hw *hw, dma_addr_t src)
+{
+ u64 snoop_bits;
+
+ snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+ ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
+ hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
+}
+
+static void set_desc_dst(struct fsldma_chan *chan,
+ struct fsl_dma_ld_hw *hw, dma_addr_t dst)
+{
+ u64 snoop_bits;
+
+ snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+ ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
+ hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
+}
+
+static void set_desc_next(struct fsldma_chan *chan,
+ struct fsl_dma_ld_hw *hw, dma_addr_t next)
+{
+ u64 snoop_bits;
+
+ snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
+ ? FSL_DMA_SNEN : 0;
+ hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
+}
+
+static void set_ld_eol(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
+{
+ u64 snoop_bits;
+
+ snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
+ ? FSL_DMA_SNEN : 0;
+
+ desc->hw.next_ln_addr = CPU_TO_DMA(chan,
+ DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
+ | snoop_bits, 64);
+}
+
+/*
+ * DMA Engine Hardware Control Helpers
+ */
+
+static void dma_init(struct fsldma_chan *chan)
+{
+ /* Reset the channel */
+ set_mr(chan, 0);
+
+ switch (chan->feature & FSL_DMA_IP_MASK) {
+ case FSL_DMA_IP_85XX:
+ /* Set the channel to below modes:
+ * EIE - Error interrupt enable
+ * EOLNIE - End of links interrupt enable
+ * BWC - Bandwidth sharing among channels
+ */
+ set_mr(chan, FSL_DMA_MR_BWC | FSL_DMA_MR_EIE
+ | FSL_DMA_MR_EOLNIE);
+ break;
+ case FSL_DMA_IP_83XX:
+ /* Set the channel to below modes:
+ * EOTIE - End-of-transfer interrupt enable
+ * PRC_RM - PCI read multiple
+ */
+ set_mr(chan, FSL_DMA_MR_EOTIE | FSL_DMA_MR_PRC_RM);
+ break;
+ }
+}
+
+static int dma_is_idle(struct fsldma_chan *chan)
+{
+ u32 sr = get_sr(chan);
+ return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
+}
+
+/*
+ * Start the DMA controller
+ *
+ * Preconditions:
+ * - the CDAR register must point to the start descriptor
+ * - the MRn[CS] bit must be cleared
+ */
+static void dma_start(struct fsldma_chan *chan)
+{
+ u32 mode;
+
+ mode = get_mr(chan);
+
+ if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
+ set_bcr(chan, 0);
+ mode |= FSL_DMA_MR_EMP_EN;
+ } else {
+ mode &= ~FSL_DMA_MR_EMP_EN;
+ }
+
+ if (chan->feature & FSL_DMA_CHAN_START_EXT) {
+ mode |= FSL_DMA_MR_EMS_EN;
+ } else {
+ mode &= ~FSL_DMA_MR_EMS_EN;
+ mode |= FSL_DMA_MR_CS;
+ }
+
+ set_mr(chan, mode);
+}
+
+static void dma_halt(struct fsldma_chan *chan)
+{
+ u32 mode;
+ int i;
+
+ /* read the mode register */
+ mode = get_mr(chan);
+
+ /*
+ * The 85xx controller supports channel abort, which will stop
+ * the current transfer. On 83xx, this bit is the transfer error
+ * mask bit, which should not be changed.
+ */
+ if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
+ mode |= FSL_DMA_MR_CA;
+ set_mr(chan, mode);
+
+ mode &= ~FSL_DMA_MR_CA;
+ }
+
+ /* stop the DMA controller */
+ mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN);
+ set_mr(chan, mode);
+
+ /* wait for the DMA controller to become idle */
+ for (i = 0; i < 100; i++) {
+ if (dma_is_idle(chan))
+ return;
+
+ udelay(10);
+ }
+
+ if (!dma_is_idle(chan))
+ chan_err(chan, "DMA halt timeout!\n");
+}
+
+/**
+ * fsl_chan_set_src_loop_size - Set source address hold transfer size
+ * @chan : Freescale DMA channel
+ * @size : Address loop size, 0 for disable loop
+ *
+ * The set source address hold transfer size. The source
+ * address hold or loop transfer size is when the DMA transfer
+ * data from source address (SA), if the loop size is 4, the DMA will
+ * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
+ * SA + 1 ... and so on.
+ */
+static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size)
+{
+ u32 mode;
+
+ mode = get_mr(chan);
+
+ switch (size) {
+ case 0:
+ mode &= ~FSL_DMA_MR_SAHE;
+ break;
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ mode |= FSL_DMA_MR_SAHE | (__ilog2(size) << 14);
+ break;
+ }
+
+ set_mr(chan, mode);
+}
+
+/**
+ * fsl_chan_set_dst_loop_size - Set destination address hold transfer size
+ * @chan : Freescale DMA channel
+ * @size : Address loop size, 0 for disable loop
+ *
+ * The set destination address hold transfer size. The destination
+ * address hold or loop transfer size is when the DMA transfer
+ * data to destination address (TA), if the loop size is 4, the DMA will
+ * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
+ * TA + 1 ... and so on.
+ */
+static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size)
+{
+ u32 mode;
+
+ mode = get_mr(chan);
+
+ switch (size) {
+ case 0:
+ mode &= ~FSL_DMA_MR_DAHE;
+ break;
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ mode |= FSL_DMA_MR_DAHE | (__ilog2(size) << 16);
+ break;
+ }
+
+ set_mr(chan, mode);
+}
+
+/**
+ * fsl_chan_set_request_count - Set DMA Request Count for external control
+ * @chan : Freescale DMA channel
+ * @size : Number of bytes to transfer in a single request
+ *
+ * The Freescale DMA channel can be controlled by the external signal DREQ#.
+ * The DMA request count is how many bytes are allowed to transfer before
+ * pausing the channel, after which a new assertion of DREQ# resumes channel
+ * operation.
+ *
+ * A size of 0 disables external pause control. The maximum size is 1024.
+ */
+static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size)
+{
+ u32 mode;
+
+ BUG_ON(size > 1024);
+
+ mode = get_mr(chan);
+ mode |= (__ilog2(size) << 24) & 0x0f000000;
+
+ set_mr(chan, mode);
+}
+
+/**
+ * fsl_chan_toggle_ext_pause - Toggle channel external pause status
+ * @chan : Freescale DMA channel
+ * @enable : 0 is disabled, 1 is enabled.
+ *
+ * The Freescale DMA channel can be controlled by the external signal DREQ#.
+ * The DMA Request Count feature should be used in addition to this feature
+ * to set the number of bytes to transfer before pausing the channel.
+ */
+static void fsl_chan_toggle_ext_pause(struct fsldma_chan *chan, int enable)
+{
+ if (enable)
+ chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
+ else
+ chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
+}
+
+/**
+ * fsl_chan_toggle_ext_start - Toggle channel external start status
+ * @chan : Freescale DMA channel
+ * @enable : 0 is disabled, 1 is enabled.
+ *
+ * If enable the external start, the channel can be started by an
+ * external DMA start pin. So the dma_start() does not start the
+ * transfer immediately. The DMA channel will wait for the
+ * control pin asserted.
+ */
+static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable)
+{
+ if (enable)
+ chan->feature |= FSL_DMA_CHAN_START_EXT;
+ else
+ chan->feature &= ~FSL_DMA_CHAN_START_EXT;
+}
+
+int fsl_dma_external_start(struct dma_chan *dchan, int enable)
+{
+ struct fsldma_chan *chan;
+
+ if (!dchan)
+ return -EINVAL;
+
+ chan = to_fsl_chan(dchan);
+
+ fsl_chan_toggle_ext_start(chan, enable);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fsl_dma_external_start);
+
+static void append_ld_queue(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
+{
+ struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
+
+ if (list_empty(&chan->ld_pending))
+ goto out_splice;
+
+ /*
+ * Add the hardware descriptor to the chain of hardware descriptors
+ * that already exists in memory.
+ *
+ * This will un-set the EOL bit of the existing transaction, and the
+ * last link in this transaction will become the EOL descriptor.
+ */
+ set_desc_next(chan, &tail->hw, desc->async_tx.phys);
+
+ /*
+ * Add the software descriptor and all children to the list
+ * of pending transactions
+ */
+out_splice:
+ list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
+}
+
+static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct fsldma_chan *chan = to_fsl_chan(tx->chan);
+ struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
+ struct fsl_desc_sw *child;
+ dma_cookie_t cookie = -EINVAL;
+
+ spin_lock_bh(&chan->desc_lock);
+
+#ifdef CONFIG_PM
+ if (unlikely(chan->pm_state != RUNNING)) {
+ chan_dbg(chan, "cannot submit due to suspend\n");
+ spin_unlock_bh(&chan->desc_lock);
+ return -1;
+ }
+#endif
+
+ /*
+ * assign cookies to all of the software descriptors
+ * that make up this transaction
+ */
+ list_for_each_entry(child, &desc->tx_list, node) {
+ cookie = dma_cookie_assign(&child->async_tx);
+ }
+
+ /* put this transaction onto the tail of the pending queue */
+ append_ld_queue(chan, desc);
+
+ spin_unlock_bh(&chan->desc_lock);
+
+ return cookie;
+}
+
+/**
+ * fsl_dma_free_descriptor - Free descriptor from channel's DMA pool.
+ * @chan : Freescale DMA channel
+ * @desc: descriptor to be freed
+ */
+static void fsl_dma_free_descriptor(struct fsldma_chan *chan,
+ struct fsl_desc_sw *desc)
+{
+ list_del(&desc->node);
+ chan_dbg(chan, "LD %p free\n", desc);
+ dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
+}
+
+/**
+ * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
+ * @chan : Freescale DMA channel
+ *
+ * Return - The descriptor allocated. NULL for failed.
+ */
+static struct fsl_desc_sw *fsl_dma_alloc_descriptor(struct fsldma_chan *chan)
+{
+ struct fsl_desc_sw *desc;
+ dma_addr_t pdesc;
+
+ desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
+ if (!desc) {
+ chan_dbg(chan, "out of memory for link descriptor\n");
+ return NULL;
+ }
+
+ memset(desc, 0, sizeof(*desc));
+ INIT_LIST_HEAD(&desc->tx_list);
+ dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
+ desc->async_tx.tx_submit = fsl_dma_tx_submit;
+ desc->async_tx.phys = pdesc;
+
+ chan_dbg(chan, "LD %p allocated\n", desc);
+
+ return desc;
+}
+
+/**
+ * fsldma_clean_completed_descriptor - free all descriptors which
+ * has been completed and acked
+ * @chan: Freescale DMA channel
+ *
+ * This function is used on all completed and acked descriptors.
+ * All descriptors should only be freed in this function.
+ */
+static void fsldma_clean_completed_descriptor(struct fsldma_chan *chan)
+{
+ struct fsl_desc_sw *desc, *_desc;
+
+ /* Run the callback for each descriptor, in order */
+ list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node)
+ if (async_tx_test_ack(&desc->async_tx))
+ fsl_dma_free_descriptor(chan, desc);
+}
+
+/**
+ * fsldma_run_tx_complete_actions - cleanup a single link descriptor
+ * @chan: Freescale DMA channel
+ * @desc: descriptor to cleanup and free
+ * @cookie: Freescale DMA transaction identifier
+ *
+ * This function is used on a descriptor which has been executed by the DMA
+ * controller. It will run any callbacks, submit any dependencies.
+ */
+static dma_cookie_t fsldma_run_tx_complete_actions(struct fsldma_chan *chan,
+ struct fsl_desc_sw *desc, dma_cookie_t cookie)
+{
+ struct dma_async_tx_descriptor *txd = &desc->async_tx;
+ dma_cookie_t ret = cookie;
+
+ BUG_ON(txd->cookie < 0);
+
+ if (txd->cookie > 0) {
+ ret = txd->cookie;
+
+ /* Run the link descriptor callback function */
+ if (txd->callback) {
+ chan_dbg(chan, "LD %p callback\n", desc);
+ txd->callback(txd->callback_param);
+ }
+ }
+
+ /* Run any dependencies */
+ dma_run_dependencies(txd);
+
+ return ret;
+}
+
+/**
+ * fsldma_clean_running_descriptor - move the completed descriptor from
+ * ld_running to ld_completed
+ * @chan: Freescale DMA channel
+ * @desc: the descriptor which is completed
+ *
+ * Free the descriptor directly if acked by async_tx api, or move it to
+ * queue ld_completed.
+ */
+static void fsldma_clean_running_descriptor(struct fsldma_chan *chan,
+ struct fsl_desc_sw *desc)
+{
+ /* Remove from the list of transactions */
+ list_del(&desc->node);
+
+ /*
+ * the client is allowed to attach dependent operations
+ * until 'ack' is set
+ */
+ if (!async_tx_test_ack(&desc->async_tx)) {
+ /*
+ * Move this descriptor to the list of descriptors which is
+ * completed, but still awaiting the 'ack' bit to be set.
+ */
+ list_add_tail(&desc->node, &chan->ld_completed);
+ return;
+ }
+
+ dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
+}
+
+/**
+ * fsl_chan_xfer_ld_queue - transfer any pending transactions
+ * @chan : Freescale DMA channel
+ *
+ * HARDWARE STATE: idle
+ * LOCKING: must hold chan->desc_lock
+ */
+static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
+{
+ struct fsl_desc_sw *desc;
+
+ /*
+ * If the list of pending descriptors is empty, then we
+ * don't need to do any work at all
+ */
+ if (list_empty(&chan->ld_pending)) {
+ chan_dbg(chan, "no pending LDs\n");
+ return;
+ }
+
+ /*
+ * The DMA controller is not idle, which means that the interrupt
+ * handler will start any queued transactions when it runs after
+ * this transaction finishes
+ */
+ if (!chan->idle) {
+ chan_dbg(chan, "DMA controller still busy\n");
+ return;
+ }
+
+ /*
+ * If there are some link descriptors which have not been
+ * transferred, we need to start the controller
+ */
+
+ /*
+ * Move all elements from the queue of pending transactions
+ * onto the list of running transactions
+ */
+ chan_dbg(chan, "idle, starting controller\n");
+ desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
+ list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
+
+ /*
+ * The 85xx DMA controller doesn't clear the channel start bit
+ * automatically at the end of a transfer. Therefore we must clear
+ * it in software before starting the transfer.
+ */
+ if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
+ u32 mode;
+
+ mode = get_mr(chan);
+ mode &= ~FSL_DMA_MR_CS;
+ set_mr(chan, mode);
+ }
+
+ /*
+ * Program the descriptor's address into the DMA controller,
+ * then start the DMA transaction
+ */
+ set_cdar(chan, desc->async_tx.phys);
+ get_cdar(chan);
+
+ dma_start(chan);
+ chan->idle = false;
+}
+
+/**
+ * fsldma_cleanup_descriptors - cleanup link descriptors which are completed
+ * and move them to ld_completed to free until flag 'ack' is set
+ * @chan: Freescale DMA channel
+ *
+ * This function is used on descriptors which have been executed by the DMA
+ * controller. It will run any callbacks, submit any dependencies, then
+ * free these descriptors if flag 'ack' is set.
+ */
+static void fsldma_cleanup_descriptors(struct fsldma_chan *chan)
+{
+ struct fsl_desc_sw *desc, *_desc;
+ dma_cookie_t cookie = 0;
+ dma_addr_t curr_phys = get_cdar(chan);
+ int seen_current = 0;
+
+ fsldma_clean_completed_descriptor(chan);
+
+ /* Run the callback for each descriptor, in order */
+ list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
+ /*
+ * do not advance past the current descriptor loaded into the
+ * hardware channel, subsequent descriptors are either in
+ * process or have not been submitted
+ */
+ if (seen_current)
+ break;
+
+ /*
+ * stop the search if we reach the current descriptor and the
+ * channel is busy
+ */
+ if (desc->async_tx.phys == curr_phys) {
+ seen_current = 1;
+ if (!dma_is_idle(chan))
+ break;
+ }
+
+ cookie = fsldma_run_tx_complete_actions(chan, desc, cookie);
+
+ fsldma_clean_running_descriptor(chan, desc);
+ }
+
+ /*
+ * Start any pending transactions automatically
+ *
+ * In the ideal case, we keep the DMA controller busy while we go
+ * ahead and free the descriptors below.
+ */
+ fsl_chan_xfer_ld_queue(chan);
+
+ if (cookie > 0)
+ chan->common.completed_cookie = cookie;
+}
+
+/**
+ * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
+ * @chan : Freescale DMA channel
+ *
+ * This function will create a dma pool for descriptor allocation.
+ *
+ * Return - The number of descriptors allocated.
+ */
+static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
+{
+ struct fsldma_chan *chan = to_fsl_chan(dchan);
+
+ /* Has this channel already been allocated? */
+ if (chan->desc_pool)
+ return 1;
+
+ /*
+ * We need the descriptor to be aligned to 32bytes
+ * for meeting FSL DMA specification requirement.
+ */
+ chan->desc_pool = dma_pool_create(chan->name, chan->dev,
+ sizeof(struct fsl_desc_sw),
+ __alignof__(struct fsl_desc_sw), 0);
+ if (!chan->desc_pool) {
+ chan_err(chan, "unable to allocate descriptor pool\n");
+ return -ENOMEM;
+ }
+
+ /* there is at least one descriptor free to be allocated */
+ return 1;
+}
+
+/**
+ * fsldma_free_desc_list - Free all descriptors in a queue
+ * @chan: Freescae DMA channel
+ * @list: the list to free
+ *
+ * LOCKING: must hold chan->desc_lock
+ */
+static void fsldma_free_desc_list(struct fsldma_chan *chan,
+ struct list_head *list)
+{
+ struct fsl_desc_sw *desc, *_desc;
+
+ list_for_each_entry_safe(desc, _desc, list, node)
+ fsl_dma_free_descriptor(chan, desc);
+}
+
+static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
+ struct list_head *list)
+{
+ struct fsl_desc_sw *desc, *_desc;
+
+ list_for_each_entry_safe_reverse(desc, _desc, list, node)
+ fsl_dma_free_descriptor(chan, desc);
+}
+
+/**
+ * fsl_dma_free_chan_resources - Free all resources of the channel.
+ * @chan : Freescale DMA channel
+ */
+static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
+{
+ struct fsldma_chan *chan = to_fsl_chan(dchan);
+
+ chan_dbg(chan, "free all channel resources\n");
+ spin_lock_bh(&chan->desc_lock);
+ fsldma_cleanup_descriptors(chan);
+ fsldma_free_desc_list(chan, &chan->ld_pending);
+ fsldma_free_desc_list(chan, &chan->ld_running);
+ fsldma_free_desc_list(chan, &chan->ld_completed);
+ spin_unlock_bh(&chan->desc_lock);
+
+ dma_pool_destroy(chan->desc_pool);
+ chan->desc_pool = NULL;
+}
+
+static struct dma_async_tx_descriptor *
+fsl_dma_prep_memcpy(struct dma_chan *dchan,
+ dma_addr_t dma_dst, dma_addr_t dma_src,
+ size_t len, unsigned long flags)
+{
+ struct fsldma_chan *chan;
+ struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
+ size_t copy;
+
+ if (!dchan)
+ return NULL;
+
+ if (!len)
+ return NULL;
+
+ chan = to_fsl_chan(dchan);
+
+ do {
+
+ /* Allocate the link descriptor from DMA pool */
+ new = fsl_dma_alloc_descriptor(chan);
+ if (!new) {
+ chan_err(chan, "%s\n", msg_ld_oom);
+ goto fail;
+ }
+
+ copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
+
+ set_desc_cnt(chan, &new->hw, copy);
+ set_desc_src(chan, &new->hw, dma_src);
+ set_desc_dst(chan, &new->hw, dma_dst);
+
+ if (!first)
+ first = new;
+ else
+ set_desc_next(chan, &prev->hw, new->async_tx.phys);
+
+ new->async_tx.cookie = 0;
+ async_tx_ack(&new->async_tx);
+
+ prev = new;
+ len -= copy;
+ dma_src += copy;
+ dma_dst += copy;
+
+ /* Insert the link descriptor to the LD ring */
+ list_add_tail(&new->node, &first->tx_list);
+ } while (len);
+
+ new->async_tx.flags = flags; /* client is in control of this ack */
+ new->async_tx.cookie = -EBUSY;
+
+ /* Set End-of-link to the last link descriptor of new list */
+ set_ld_eol(chan, new);
+
+ return &first->async_tx;
+
+fail:
+ if (!first)
+ return NULL;
+
+ fsldma_free_desc_list_reverse(chan, &first->tx_list);
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
+ struct scatterlist *dst_sg, unsigned int dst_nents,
+ struct scatterlist *src_sg, unsigned int src_nents,
+ unsigned long flags)
+{
+ struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
+ struct fsldma_chan *chan = to_fsl_chan(dchan);
+ size_t dst_avail, src_avail;
+ dma_addr_t dst, src;
+ size_t len;
+
+ /* basic sanity checks */
+ if (dst_nents == 0 || src_nents == 0)
+ return NULL;
+
+ if (dst_sg == NULL || src_sg == NULL)
+ return NULL;
+
+ /*
+ * TODO: should we check that both scatterlists have the same
+ * TODO: number of bytes in total? Is that really an error?
+ */
+
+ /* get prepared for the loop */
+ dst_avail = sg_dma_len(dst_sg);
+ src_avail = sg_dma_len(src_sg);
+
+ /* run until we are out of scatterlist entries */
+ while (true) {
+
+ /* create the largest transaction possible */
+ len = min_t(size_t, src_avail, dst_avail);
+ len = min_t(size_t, len, FSL_DMA_BCR_MAX_CNT);
+ if (len == 0)
+ goto fetch;
+
+ dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
+ src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
+
+ /* allocate and populate the descriptor */
+ new = fsl_dma_alloc_descriptor(chan);
+ if (!new) {
+ chan_err(chan, "%s\n", msg_ld_oom);
+ goto fail;
+ }
+
+ set_desc_cnt(chan, &new->hw, len);
+ set_desc_src(chan, &new->hw, src);
+ set_desc_dst(chan, &new->hw, dst);
+
+ if (!first)
+ first = new;
+ else
+ set_desc_next(chan, &prev->hw, new->async_tx.phys);
+
+ new->async_tx.cookie = 0;
+ async_tx_ack(&new->async_tx);
+ prev = new;
+
+ /* Insert the link descriptor to the LD ring */
+ list_add_tail(&new->node, &first->tx_list);
+
+ /* update metadata */
+ dst_avail -= len;
+ src_avail -= len;
+
+fetch:
+ /* fetch the next dst scatterlist entry */
+ if (dst_avail == 0) {
+
+ /* no more entries: we're done */
+ if (dst_nents == 0)
+ break;
+
+ /* fetch the next entry: if there are no more: done */
+ dst_sg = sg_next(dst_sg);
+ if (dst_sg == NULL)
+ break;
+
+ dst_nents--;
+ dst_avail = sg_dma_len(dst_sg);
+ }
+
+ /* fetch the next src scatterlist entry */
+ if (src_avail == 0) {
+
+ /* no more entries: we're done */
+ if (src_nents == 0)
+ break;
+
+ /* fetch the next entry: if there are no more: done */
+ src_sg = sg_next(src_sg);
+ if (src_sg == NULL)
+ break;
+
+ src_nents--;
+ src_avail = sg_dma_len(src_sg);
+ }
+ }
+
+ new->async_tx.flags = flags; /* client is in control of this ack */
+ new->async_tx.cookie = -EBUSY;
+
+ /* Set End-of-link to the last link descriptor of new list */
+ set_ld_eol(chan, new);
+
+ return &first->async_tx;
+
+fail:
+ if (!first)
+ return NULL;
+
+ fsldma_free_desc_list_reverse(chan, &first->tx_list);
+ return NULL;
+}
+
+static int fsl_dma_device_terminate_all(struct dma_chan *dchan)
+{
+ struct fsldma_chan *chan;
+
+ if (!dchan)
+ return -EINVAL;
+
+ chan = to_fsl_chan(dchan);
+
+ spin_lock_bh(&chan->desc_lock);
+
+ /* Halt the DMA engine */
+ dma_halt(chan);
+
+ /* Remove and free all of the descriptors in the LD queue */
+ fsldma_free_desc_list(chan, &chan->ld_pending);
+ fsldma_free_desc_list(chan, &chan->ld_running);
+ fsldma_free_desc_list(chan, &chan->ld_completed);
+ chan->idle = true;
+
+ spin_unlock_bh(&chan->desc_lock);
+ return 0;
+}
+
+static int fsl_dma_device_config(struct dma_chan *dchan,
+ struct dma_slave_config *config)
+{
+ struct fsldma_chan *chan;
+ int size;
+
+ if (!dchan)
+ return -EINVAL;
+
+ chan = to_fsl_chan(dchan);
+
+ /* make sure the channel supports setting burst size */
+ if (!chan->set_request_count)
+ return -ENXIO;
+
+ /* we set the controller burst size depending on direction */
+ if (config->direction == DMA_MEM_TO_DEV)
+ size = config->dst_addr_width * config->dst_maxburst;
+ else
+ size = config->src_addr_width * config->src_maxburst;
+
+ chan->set_request_count(chan, size);
+ return 0;
+}
+
+
+/**
+ * fsl_dma_memcpy_issue_pending - Issue the DMA start command
+ * @chan : Freescale DMA channel
+ */
+static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
+{
+ struct fsldma_chan *chan = to_fsl_chan(dchan);
+
+ spin_lock_bh(&chan->desc_lock);
+ fsl_chan_xfer_ld_queue(chan);
+ spin_unlock_bh(&chan->desc_lock);
+}
+
+/**
+ * fsl_tx_status - Determine the DMA status
+ * @chan : Freescale DMA channel
+ */
+static enum dma_status fsl_tx_status(struct dma_chan *dchan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct fsldma_chan *chan = to_fsl_chan(dchan);
+ enum dma_status ret;
+
+ ret = dma_cookie_status(dchan, cookie, txstate);
+ if (ret == DMA_COMPLETE)
+ return ret;
+
+ spin_lock_bh(&chan->desc_lock);
+ fsldma_cleanup_descriptors(chan);
+ spin_unlock_bh(&chan->desc_lock);
+
+ return dma_cookie_status(dchan, cookie, txstate);
+}
+
+/*----------------------------------------------------------------------------*/
+/* Interrupt Handling */
+/*----------------------------------------------------------------------------*/
+
+static irqreturn_t fsldma_chan_irq(int irq, void *data)
+{
+ struct fsldma_chan *chan = data;
+ u32 stat;
+
+ /* save and clear the status register */
+ stat = get_sr(chan);
+ set_sr(chan, stat);
+ chan_dbg(chan, "irq: stat = 0x%x\n", stat);
+
+ /* check that this was really our device */
+ stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
+ if (!stat)
+ return IRQ_NONE;
+
+ if (stat & FSL_DMA_SR_TE)
+ chan_err(chan, "Transfer Error!\n");
+
+ /*
+ * Programming Error
+ * The DMA_INTERRUPT async_tx is a NULL transfer, which will
+ * trigger a PE interrupt.
+ */
+ if (stat & FSL_DMA_SR_PE) {
+ chan_dbg(chan, "irq: Programming Error INT\n");
+ stat &= ~FSL_DMA_SR_PE;
+ if (get_bcr(chan) != 0)
+ chan_err(chan, "Programming Error!\n");
+ }
+
+ /*
+ * For MPC8349, EOCDI event need to update cookie
+ * and start the next transfer if it exist.
+ */
+ if (stat & FSL_DMA_SR_EOCDI) {
+ chan_dbg(chan, "irq: End-of-Chain link INT\n");
+ stat &= ~FSL_DMA_SR_EOCDI;
+ }
+
+ /*
+ * If it current transfer is the end-of-transfer,
+ * we should clear the Channel Start bit for
+ * prepare next transfer.
+ */
+ if (stat & FSL_DMA_SR_EOLNI) {
+ chan_dbg(chan, "irq: End-of-link INT\n");
+ stat &= ~FSL_DMA_SR_EOLNI;
+ }
+
+ /* check that the DMA controller is really idle */
+ if (!dma_is_idle(chan))
+ chan_err(chan, "irq: controller not idle!\n");
+
+ /* check that we handled all of the bits */
+ if (stat)
+ chan_err(chan, "irq: unhandled sr 0x%08x\n", stat);
+
+ /*
+ * Schedule the tasklet to handle all cleanup of the current
+ * transaction. It will start a new transaction if there is
+ * one pending.
+ */
+ tasklet_schedule(&chan->tasklet);
+ chan_dbg(chan, "irq: Exit\n");
+ return IRQ_HANDLED;
+}
+
+static void dma_do_tasklet(unsigned long data)
+{
+ struct fsldma_chan *chan = (struct fsldma_chan *)data;
+
+ chan_dbg(chan, "tasklet entry\n");
+
+ spin_lock_bh(&chan->desc_lock);
+
+ /* the hardware is now idle and ready for more */
+ chan->idle = true;
+
+ /* Run all cleanup for descriptors which have been completed */
+ fsldma_cleanup_descriptors(chan);
+
+ spin_unlock_bh(&chan->desc_lock);
+
+ chan_dbg(chan, "tasklet exit\n");
+}
+
+static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
+{
+ struct fsldma_device *fdev = data;
+ struct fsldma_chan *chan;
+ unsigned int handled = 0;
+ u32 gsr, mask;
+ int i;
+
+ gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs)
+ : in_le32(fdev->regs);
+ mask = 0xff000000;
+ dev_dbg(fdev->dev, "IRQ: gsr 0x%.8x\n", gsr);
+
+ for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
+ chan = fdev->chan[i];
+ if (!chan)
+ continue;
+
+ if (gsr & mask) {
+ dev_dbg(fdev->dev, "IRQ: chan %d\n", chan->id);
+ fsldma_chan_irq(irq, chan);
+ handled++;
+ }
+
+ gsr &= ~mask;
+ mask >>= 8;
+ }
+
+ return IRQ_RETVAL(handled);
+}
+
+static void fsldma_free_irqs(struct fsldma_device *fdev)
+{
+ struct fsldma_chan *chan;
+ int i;
+
+ if (fdev->irq != NO_IRQ) {
+ dev_dbg(fdev->dev, "free per-controller IRQ\n");
+ free_irq(fdev->irq, fdev);
+ return;
+ }
+
+ for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
+ chan = fdev->chan[i];
+ if (chan && chan->irq != NO_IRQ) {
+ chan_dbg(chan, "free per-channel IRQ\n");
+ free_irq(chan->irq, chan);
+ }
+ }
+}
+
+static int fsldma_request_irqs(struct fsldma_device *fdev)
+{
+ struct fsldma_chan *chan;
+ int ret;
+ int i;
+
+ /* if we have a per-controller IRQ, use that */
+ if (fdev->irq != NO_IRQ) {
+ dev_dbg(fdev->dev, "request per-controller IRQ\n");
+ ret = request_irq(fdev->irq, fsldma_ctrl_irq, IRQF_SHARED,
+ "fsldma-controller", fdev);
+ return ret;
+ }
+
+ /* no per-controller IRQ, use the per-channel IRQs */
+ for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
+ chan = fdev->chan[i];
+ if (!chan)
+ continue;
+
+ if (chan->irq == NO_IRQ) {
+ chan_err(chan, "interrupts property missing in device tree\n");
+ ret = -ENODEV;
+ goto out_unwind;
+ }
+
+ chan_dbg(chan, "request per-channel IRQ\n");
+ ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
+ "fsldma-chan", chan);
+ if (ret) {
+ chan_err(chan, "unable to request per-channel IRQ\n");
+ goto out_unwind;
+ }
+ }
+
+ return 0;
+
+out_unwind:
+ for (/* none */; i >= 0; i--) {
+ chan = fdev->chan[i];
+ if (!chan)
+ continue;
+
+ if (chan->irq == NO_IRQ)
+ continue;
+
+ free_irq(chan->irq, chan);
+ }
+
+ return ret;
+}
+
+/*----------------------------------------------------------------------------*/
+/* OpenFirmware Subsystem */
+/*----------------------------------------------------------------------------*/
+
+static int fsl_dma_chan_probe(struct fsldma_device *fdev,
+ struct device_node *node, u32 feature, const char *compatible)
+{
+ struct fsldma_chan *chan;
+ struct resource res;
+ int err;
+
+ /* alloc channel */
+ chan = kzalloc(sizeof(*chan), GFP_KERNEL);
+ if (!chan) {
+ dev_err(fdev->dev, "no free memory for DMA channels!\n");
+ err = -ENOMEM;
+ goto out_return;
+ }
+
+ /* ioremap registers for use */
+ chan->regs = of_iomap(node, 0);
+ if (!chan->regs) {
+ dev_err(fdev->dev, "unable to ioremap registers\n");
+ err = -ENOMEM;
+ goto out_free_chan;
+ }
+
+ err = of_address_to_resource(node, 0, &res);
+ if (err) {
+ dev_err(fdev->dev, "unable to find 'reg' property\n");
+ goto out_iounmap_regs;
+ }
+
+ chan->feature = feature;
+ if (!fdev->feature)
+ fdev->feature = chan->feature;
+
+ /*
+ * If the DMA device's feature is different than the feature
+ * of its channels, report the bug
+ */
+ WARN_ON(fdev->feature != chan->feature);
+
+ chan->dev = fdev->dev;
+ chan->id = (res.start & 0xfff) < 0x300 ?
+ ((res.start - 0x100) & 0xfff) >> 7 :
+ ((res.start - 0x200) & 0xfff) >> 7;
+ if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
+ dev_err(fdev->dev, "too many channels for device\n");
+ err = -EINVAL;
+ goto out_iounmap_regs;
+ }
+
+ fdev->chan[chan->id] = chan;
+ tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
+ snprintf(chan->name, sizeof(chan->name), "chan%d", chan->id);
+
+ /* Initialize the channel */
+ dma_init(chan);
+
+ /* Clear cdar registers */
+ set_cdar(chan, 0);
+
+ switch (chan->feature & FSL_DMA_IP_MASK) {
+ case FSL_DMA_IP_85XX:
+ chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
+ case FSL_DMA_IP_83XX:
+ chan->toggle_ext_start = fsl_chan_toggle_ext_start;
+ chan->set_src_loop_size = fsl_chan_set_src_loop_size;
+ chan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
+ chan->set_request_count = fsl_chan_set_request_count;
+ }
+
+ spin_lock_init(&chan->desc_lock);
+ INIT_LIST_HEAD(&chan->ld_pending);
+ INIT_LIST_HEAD(&chan->ld_running);
+ INIT_LIST_HEAD(&chan->ld_completed);
+ chan->idle = true;
+#ifdef CONFIG_PM
+ chan->pm_state = RUNNING;
+#endif
+
+ chan->common.device = &fdev->common;
+ dma_cookie_init(&chan->common);
+
+ /* find the IRQ line, if it exists in the device tree */
+ chan->irq = irq_of_parse_and_map(node, 0);
+
+ /* Add the channel to DMA device channel list */
+ list_add_tail(&chan->common.device_node, &fdev->common.channels);
+
+ dev_info(fdev->dev, "#%d (%s), irq %d\n", chan->id, compatible,
+ chan->irq != NO_IRQ ? chan->irq : fdev->irq);
+
+ return 0;
+
+out_iounmap_regs:
+ iounmap(chan->regs);
+out_free_chan:
+ kfree(chan);
+out_return:
+ return err;
+}
+
+static void fsl_dma_chan_remove(struct fsldma_chan *chan)
+{
+ irq_dispose_mapping(chan->irq);
+ list_del(&chan->common.device_node);
+ iounmap(chan->regs);
+ kfree(chan);
+}
+
+static int fsldma_of_probe(struct platform_device *op)
+{
+ struct fsldma_device *fdev;
+ struct device_node *child;
+ int err;
+
+ fdev = kzalloc(sizeof(*fdev), GFP_KERNEL);
+ if (!fdev) {
+ dev_err(&op->dev, "No enough memory for 'priv'\n");
+ err = -ENOMEM;
+ goto out_return;
+ }
+
+ fdev->dev = &op->dev;
+ INIT_LIST_HEAD(&fdev->common.channels);
+
+ /* ioremap the registers for use */
+ fdev->regs = of_iomap(op->dev.of_node, 0);
+ if (!fdev->regs) {
+ dev_err(&op->dev, "unable to ioremap registers\n");
+ err = -ENOMEM;
+ goto out_free_fdev;
+ }
+
+ /* map the channel IRQ if it exists, but don't hookup the handler yet */
+ fdev->irq = irq_of_parse_and_map(op->dev.of_node, 0);
+
+ dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
+ dma_cap_set(DMA_SG, fdev->common.cap_mask);
+ dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
+ fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
+ fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
+ fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
+ fdev->common.device_prep_dma_sg = fsl_dma_prep_sg;
+ fdev->common.device_tx_status = fsl_tx_status;
+ fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
+ fdev->common.device_config = fsl_dma_device_config;
+ fdev->common.device_terminate_all = fsl_dma_device_terminate_all;
+ fdev->common.dev = &op->dev;
+
+ fdev->common.src_addr_widths = FSL_DMA_BUSWIDTHS;
+ fdev->common.dst_addr_widths = FSL_DMA_BUSWIDTHS;
+ fdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ fdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
+
+ dma_set_mask(&(op->dev), DMA_BIT_MASK(36));
+
+ platform_set_drvdata(op, fdev);
+
+ /*
+ * We cannot use of_platform_bus_probe() because there is no
+ * of_platform_bus_remove(). Instead, we manually instantiate every DMA
+ * channel object.
+ */
+ for_each_child_of_node(op->dev.of_node, child) {
+ if (of_device_is_compatible(child, "fsl,eloplus-dma-channel")) {
+ fsl_dma_chan_probe(fdev, child,
+ FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
+ "fsl,eloplus-dma-channel");
+ }
+
+ if (of_device_is_compatible(child, "fsl,elo-dma-channel")) {
+ fsl_dma_chan_probe(fdev, child,
+ FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
+ "fsl,elo-dma-channel");
+ }
+ }
+
+ /*
+ * Hookup the IRQ handler(s)
+ *
+ * If we have a per-controller interrupt, we prefer that to the
+ * per-channel interrupts to reduce the number of shared interrupt
+ * handlers on the same IRQ line
+ */
+ err = fsldma_request_irqs(fdev);
+ if (err) {
+ dev_err(fdev->dev, "unable to request IRQs\n");
+ goto out_free_fdev;
+ }
+
+ dma_async_device_register(&fdev->common);
+ return 0;
+
+out_free_fdev:
+ irq_dispose_mapping(fdev->irq);
+ kfree(fdev);
+out_return:
+ return err;
+}
+
+static int fsldma_of_remove(struct platform_device *op)
+{
+ struct fsldma_device *fdev;
+ unsigned int i;
+
+ fdev = platform_get_drvdata(op);
+ dma_async_device_unregister(&fdev->common);
+
+ fsldma_free_irqs(fdev);
+
+ for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
+ if (fdev->chan[i])
+ fsl_dma_chan_remove(fdev->chan[i]);
+ }
+
+ iounmap(fdev->regs);
+ kfree(fdev);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int fsldma_suspend_late(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct fsldma_device *fdev = platform_get_drvdata(pdev);
+ struct fsldma_chan *chan;
+ int i;
+
+ for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
+ chan = fdev->chan[i];
+ if (!chan)
+ continue;
+
+ spin_lock_bh(&chan->desc_lock);
+ if (unlikely(!chan->idle))
+ goto out;
+ chan->regs_save.mr = get_mr(chan);
+ chan->pm_state = SUSPENDED;
+ spin_unlock_bh(&chan->desc_lock);
+ }
+ return 0;
+
+out:
+ for (; i >= 0; i--) {
+ chan = fdev->chan[i];
+ if (!chan)
+ continue;
+ chan->pm_state = RUNNING;
+ spin_unlock_bh(&chan->desc_lock);
+ }
+ return -EBUSY;
+}
+
+static int fsldma_resume_early(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct fsldma_device *fdev = platform_get_drvdata(pdev);
+ struct fsldma_chan *chan;
+ u32 mode;
+ int i;
+
+ for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
+ chan = fdev->chan[i];
+ if (!chan)
+ continue;
+
+ spin_lock_bh(&chan->desc_lock);
+ mode = chan->regs_save.mr
+ & ~FSL_DMA_MR_CS & ~FSL_DMA_MR_CC & ~FSL_DMA_MR_CA;
+ set_mr(chan, mode);
+ chan->pm_state = RUNNING;
+ spin_unlock_bh(&chan->desc_lock);
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops fsldma_pm_ops = {
+ .suspend_late = fsldma_suspend_late,
+ .resume_early = fsldma_resume_early,
+};
+#endif
+
+static const struct of_device_id fsldma_of_ids[] = {
+ { .compatible = "fsl,elo3-dma", },
+ { .compatible = "fsl,eloplus-dma", },
+ { .compatible = "fsl,elo-dma", },
+ {}
+};
+
+static struct platform_driver fsldma_of_driver = {
+ .driver = {
+ .name = "fsl-elo-dma",
+ .of_match_table = fsldma_of_ids,
+#ifdef CONFIG_PM
+ .pm = &fsldma_pm_ops,
+#endif
+ },
+ .probe = fsldma_of_probe,
+ .remove = fsldma_of_remove,
+};
+
+/*----------------------------------------------------------------------------*/
+/* Module Init / Exit */
+/*----------------------------------------------------------------------------*/
+
+static __init int fsldma_init(void)
+{
+ pr_info("Freescale Elo series DMA driver\n");
+ return platform_driver_register(&fsldma_of_driver);
+}
+
+static void __exit fsldma_exit(void)
+{
+ platform_driver_unregister(&fsldma_of_driver);
+}
+
+subsys_initcall(fsldma_init);
+module_exit(fsldma_exit);
+
+MODULE_DESCRIPTION("Freescale Elo series DMA driver");
+MODULE_LICENSE("GPL");