summaryrefslogtreecommitdiffstats
path: root/drivers/dma/sh/shdma-base.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/dma/sh/shdma-base.c1062
1 files changed, 1062 insertions, 0 deletions
diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c
new file mode 100644
index 000000000..7f72b3f4c
--- /dev/null
+++ b/drivers/dma/sh/shdma-base.c
@@ -0,0 +1,1062 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Dmaengine driver base library for DMA controllers, found on SH-based SoCs
+ *
+ * extracted from shdma.c
+ *
+ * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
+ * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
+ * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
+ */
+
+#include <linux/delay.h>
+#include <linux/shdma-base.h>
+#include <linux/dmaengine.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "../dmaengine.h"
+
+/* DMA descriptor control */
+enum shdma_desc_status {
+ DESC_IDLE,
+ DESC_PREPARED,
+ DESC_SUBMITTED,
+ DESC_COMPLETED, /* completed, have to call callback */
+ DESC_WAITING, /* callback called, waiting for ack / re-submit */
+};
+
+#define NR_DESCS_PER_CHANNEL 32
+
+#define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan)
+#define to_shdma_dev(d) container_of(d, struct shdma_dev, dma_dev)
+
+/*
+ * For slave DMA we assume, that there is a finite number of DMA slaves in the
+ * system, and that each such slave can only use a finite number of channels.
+ * We use slave channel IDs to make sure, that no such slave channel ID is
+ * allocated more than once.
+ */
+static unsigned int slave_num = 256;
+module_param(slave_num, uint, 0444);
+
+/* A bitmask with slave_num bits */
+static unsigned long *shdma_slave_used;
+
+/* Called under spin_lock_irq(&schan->chan_lock") */
+static void shdma_chan_xfer_ld_queue(struct shdma_chan *schan)
+{
+ struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
+ const struct shdma_ops *ops = sdev->ops;
+ struct shdma_desc *sdesc;
+
+ /* DMA work check */
+ if (ops->channel_busy(schan))
+ return;
+
+ /* Find the first not transferred descriptor */
+ list_for_each_entry(sdesc, &schan->ld_queue, node)
+ if (sdesc->mark == DESC_SUBMITTED) {
+ ops->start_xfer(schan, sdesc);
+ break;
+ }
+}
+
+static dma_cookie_t shdma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct shdma_desc *chunk, *c, *desc =
+ container_of(tx, struct shdma_desc, async_tx);
+ struct shdma_chan *schan = to_shdma_chan(tx->chan);
+ dma_async_tx_callback callback = tx->callback;
+ dma_cookie_t cookie;
+ bool power_up;
+
+ spin_lock_irq(&schan->chan_lock);
+
+ power_up = list_empty(&schan->ld_queue);
+
+ cookie = dma_cookie_assign(tx);
+
+ /* Mark all chunks of this descriptor as submitted, move to the queue */
+ list_for_each_entry_safe(chunk, c, desc->node.prev, node) {
+ /*
+ * All chunks are on the global ld_free, so, we have to find
+ * the end of the chain ourselves
+ */
+ if (chunk != desc && (chunk->mark == DESC_IDLE ||
+ chunk->async_tx.cookie > 0 ||
+ chunk->async_tx.cookie == -EBUSY ||
+ &chunk->node == &schan->ld_free))
+ break;
+ chunk->mark = DESC_SUBMITTED;
+ if (chunk->chunks == 1) {
+ chunk->async_tx.callback = callback;
+ chunk->async_tx.callback_param = tx->callback_param;
+ } else {
+ /* Callback goes to the last chunk */
+ chunk->async_tx.callback = NULL;
+ }
+ chunk->cookie = cookie;
+ list_move_tail(&chunk->node, &schan->ld_queue);
+
+ dev_dbg(schan->dev, "submit #%d@%p on %d\n",
+ tx->cookie, &chunk->async_tx, schan->id);
+ }
+
+ if (power_up) {
+ int ret;
+ schan->pm_state = SHDMA_PM_BUSY;
+
+ ret = pm_runtime_get(schan->dev);
+
+ spin_unlock_irq(&schan->chan_lock);
+ if (ret < 0)
+ dev_err(schan->dev, "%s(): GET = %d\n", __func__, ret);
+
+ pm_runtime_barrier(schan->dev);
+
+ spin_lock_irq(&schan->chan_lock);
+
+ /* Have we been reset, while waiting? */
+ if (schan->pm_state != SHDMA_PM_ESTABLISHED) {
+ struct shdma_dev *sdev =
+ to_shdma_dev(schan->dma_chan.device);
+ const struct shdma_ops *ops = sdev->ops;
+ dev_dbg(schan->dev, "Bring up channel %d\n",
+ schan->id);
+ /*
+ * TODO: .xfer_setup() might fail on some platforms.
+ * Make it int then, on error remove chunks from the
+ * queue again
+ */
+ ops->setup_xfer(schan, schan->slave_id);
+
+ if (schan->pm_state == SHDMA_PM_PENDING)
+ shdma_chan_xfer_ld_queue(schan);
+ schan->pm_state = SHDMA_PM_ESTABLISHED;
+ }
+ } else {
+ /*
+ * Tell .device_issue_pending() not to run the queue, interrupts
+ * will do it anyway
+ */
+ schan->pm_state = SHDMA_PM_PENDING;
+ }
+
+ spin_unlock_irq(&schan->chan_lock);
+
+ return cookie;
+}
+
+/* Called with desc_lock held */
+static struct shdma_desc *shdma_get_desc(struct shdma_chan *schan)
+{
+ struct shdma_desc *sdesc;
+
+ list_for_each_entry(sdesc, &schan->ld_free, node)
+ if (sdesc->mark != DESC_PREPARED) {
+ BUG_ON(sdesc->mark != DESC_IDLE);
+ list_del(&sdesc->node);
+ return sdesc;
+ }
+
+ return NULL;
+}
+
+static int shdma_setup_slave(struct shdma_chan *schan, dma_addr_t slave_addr)
+{
+ struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
+ const struct shdma_ops *ops = sdev->ops;
+ int ret, match;
+
+ if (schan->dev->of_node) {
+ match = schan->hw_req;
+ ret = ops->set_slave(schan, match, slave_addr, true);
+ if (ret < 0)
+ return ret;
+ } else {
+ match = schan->real_slave_id;
+ }
+
+ if (schan->real_slave_id < 0 || schan->real_slave_id >= slave_num)
+ return -EINVAL;
+
+ if (test_and_set_bit(schan->real_slave_id, shdma_slave_used))
+ return -EBUSY;
+
+ ret = ops->set_slave(schan, match, slave_addr, false);
+ if (ret < 0) {
+ clear_bit(schan->real_slave_id, shdma_slave_used);
+ return ret;
+ }
+
+ schan->slave_id = schan->real_slave_id;
+
+ return 0;
+}
+
+static int shdma_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+ struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
+ const struct shdma_ops *ops = sdev->ops;
+ struct shdma_desc *desc;
+ struct shdma_slave *slave = chan->private;
+ int ret, i;
+
+ /*
+ * This relies on the guarantee from dmaengine that alloc_chan_resources
+ * never runs concurrently with itself or free_chan_resources.
+ */
+ if (slave) {
+ /* Legacy mode: .private is set in filter */
+ schan->real_slave_id = slave->slave_id;
+ ret = shdma_setup_slave(schan, 0);
+ if (ret < 0)
+ goto esetslave;
+ } else {
+ /* Normal mode: real_slave_id was set by filter */
+ schan->slave_id = -EINVAL;
+ }
+
+ schan->desc = kcalloc(NR_DESCS_PER_CHANNEL,
+ sdev->desc_size, GFP_KERNEL);
+ if (!schan->desc) {
+ ret = -ENOMEM;
+ goto edescalloc;
+ }
+ schan->desc_num = NR_DESCS_PER_CHANNEL;
+
+ for (i = 0; i < NR_DESCS_PER_CHANNEL; i++) {
+ desc = ops->embedded_desc(schan->desc, i);
+ dma_async_tx_descriptor_init(&desc->async_tx,
+ &schan->dma_chan);
+ desc->async_tx.tx_submit = shdma_tx_submit;
+ desc->mark = DESC_IDLE;
+
+ list_add(&desc->node, &schan->ld_free);
+ }
+
+ return NR_DESCS_PER_CHANNEL;
+
+edescalloc:
+ if (slave)
+esetslave:
+ clear_bit(slave->slave_id, shdma_slave_used);
+ chan->private = NULL;
+ return ret;
+}
+
+/*
+ * This is the standard shdma filter function to be used as a replacement to the
+ * "old" method, using the .private pointer.
+ * You always have to pass a valid slave id as the argument, old drivers that
+ * pass ERR_PTR(-EINVAL) as a filter parameter and set it up in dma_slave_config
+ * need to be updated so we can remove the slave_id field from dma_slave_config.
+ * parameter. If this filter is used, the slave driver, after calling
+ * dma_request_channel(), will also have to call dmaengine_slave_config() with
+ * .direction, and either .src_addr or .dst_addr set.
+ *
+ * NOTE: this filter doesn't support multiple DMAC drivers with the DMA_SLAVE
+ * capability! If this becomes a requirement, hardware glue drivers, using this
+ * services would have to provide their own filters, which first would check
+ * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do
+ * this, and only then, in case of a match, call this common filter.
+ * NOTE 2: This filter function is also used in the DT case by shdma_of_xlate().
+ * In that case the MID-RID value is used for slave channel filtering and is
+ * passed to this function in the "arg" parameter.
+ */
+bool shdma_chan_filter(struct dma_chan *chan, void *arg)
+{
+ struct shdma_chan *schan;
+ struct shdma_dev *sdev;
+ int slave_id = (long)arg;
+ int ret;
+
+ /* Only support channels handled by this driver. */
+ if (chan->device->device_alloc_chan_resources !=
+ shdma_alloc_chan_resources)
+ return false;
+
+ schan = to_shdma_chan(chan);
+ sdev = to_shdma_dev(chan->device);
+
+ /*
+ * For DT, the schan->slave_id field is generated by the
+ * set_slave function from the slave ID that is passed in
+ * from xlate. For the non-DT case, the slave ID is
+ * directly passed into the filter function by the driver
+ */
+ if (schan->dev->of_node) {
+ ret = sdev->ops->set_slave(schan, slave_id, 0, true);
+ if (ret < 0)
+ return false;
+
+ schan->real_slave_id = schan->slave_id;
+ return true;
+ }
+
+ if (slave_id < 0) {
+ /* No slave requested - arbitrary channel */
+ dev_warn(sdev->dma_dev.dev, "invalid slave ID passed to dma_request_slave\n");
+ return true;
+ }
+
+ if (slave_id >= slave_num)
+ return false;
+
+ ret = sdev->ops->set_slave(schan, slave_id, 0, true);
+ if (ret < 0)
+ return false;
+
+ schan->real_slave_id = slave_id;
+
+ return true;
+}
+EXPORT_SYMBOL(shdma_chan_filter);
+
+static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all)
+{
+ struct shdma_desc *desc, *_desc;
+ /* Is the "exposed" head of a chain acked? */
+ bool head_acked = false;
+ dma_cookie_t cookie = 0;
+ dma_async_tx_callback callback = NULL;
+ struct dmaengine_desc_callback cb;
+ unsigned long flags;
+ LIST_HEAD(cyclic_list);
+
+ memset(&cb, 0, sizeof(cb));
+ spin_lock_irqsave(&schan->chan_lock, flags);
+ list_for_each_entry_safe(desc, _desc, &schan->ld_queue, node) {
+ struct dma_async_tx_descriptor *tx = &desc->async_tx;
+
+ BUG_ON(tx->cookie > 0 && tx->cookie != desc->cookie);
+ BUG_ON(desc->mark != DESC_SUBMITTED &&
+ desc->mark != DESC_COMPLETED &&
+ desc->mark != DESC_WAITING);
+
+ /*
+ * queue is ordered, and we use this loop to (1) clean up all
+ * completed descriptors, and to (2) update descriptor flags of
+ * any chunks in a (partially) completed chain
+ */
+ if (!all && desc->mark == DESC_SUBMITTED &&
+ desc->cookie != cookie)
+ break;
+
+ if (tx->cookie > 0)
+ cookie = tx->cookie;
+
+ if (desc->mark == DESC_COMPLETED && desc->chunks == 1) {
+ if (schan->dma_chan.completed_cookie != desc->cookie - 1)
+ dev_dbg(schan->dev,
+ "Completing cookie %d, expected %d\n",
+ desc->cookie,
+ schan->dma_chan.completed_cookie + 1);
+ schan->dma_chan.completed_cookie = desc->cookie;
+ }
+
+ /* Call callback on the last chunk */
+ if (desc->mark == DESC_COMPLETED && tx->callback) {
+ desc->mark = DESC_WAITING;
+ dmaengine_desc_get_callback(tx, &cb);
+ callback = tx->callback;
+ dev_dbg(schan->dev, "descriptor #%d@%p on %d callback\n",
+ tx->cookie, tx, schan->id);
+ BUG_ON(desc->chunks != 1);
+ break;
+ }
+
+ if (tx->cookie > 0 || tx->cookie == -EBUSY) {
+ if (desc->mark == DESC_COMPLETED) {
+ BUG_ON(tx->cookie < 0);
+ desc->mark = DESC_WAITING;
+ }
+ head_acked = async_tx_test_ack(tx);
+ } else {
+ switch (desc->mark) {
+ case DESC_COMPLETED:
+ desc->mark = DESC_WAITING;
+ fallthrough;
+ case DESC_WAITING:
+ if (head_acked)
+ async_tx_ack(&desc->async_tx);
+ }
+ }
+
+ dev_dbg(schan->dev, "descriptor %p #%d completed.\n",
+ tx, tx->cookie);
+
+ if (((desc->mark == DESC_COMPLETED ||
+ desc->mark == DESC_WAITING) &&
+ async_tx_test_ack(&desc->async_tx)) || all) {
+
+ if (all || !desc->cyclic) {
+ /* Remove from ld_queue list */
+ desc->mark = DESC_IDLE;
+ list_move(&desc->node, &schan->ld_free);
+ } else {
+ /* reuse as cyclic */
+ desc->mark = DESC_SUBMITTED;
+ list_move_tail(&desc->node, &cyclic_list);
+ }
+
+ if (list_empty(&schan->ld_queue)) {
+ dev_dbg(schan->dev, "Bring down channel %d\n", schan->id);
+ pm_runtime_put(schan->dev);
+ schan->pm_state = SHDMA_PM_ESTABLISHED;
+ } else if (schan->pm_state == SHDMA_PM_PENDING) {
+ shdma_chan_xfer_ld_queue(schan);
+ }
+ }
+ }
+
+ if (all && !callback)
+ /*
+ * Terminating and the loop completed normally: forgive
+ * uncompleted cookies
+ */
+ schan->dma_chan.completed_cookie = schan->dma_chan.cookie;
+
+ list_splice_tail(&cyclic_list, &schan->ld_queue);
+
+ spin_unlock_irqrestore(&schan->chan_lock, flags);
+
+ dmaengine_desc_callback_invoke(&cb, NULL);
+
+ return callback;
+}
+
+/*
+ * shdma_chan_ld_cleanup - Clean up link descriptors
+ *
+ * Clean up the ld_queue of DMA channel.
+ */
+static void shdma_chan_ld_cleanup(struct shdma_chan *schan, bool all)
+{
+ while (__ld_cleanup(schan, all))
+ ;
+}
+
+/*
+ * shdma_free_chan_resources - Free all resources of the channel.
+ */
+static void shdma_free_chan_resources(struct dma_chan *chan)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+ struct shdma_dev *sdev = to_shdma_dev(chan->device);
+ const struct shdma_ops *ops = sdev->ops;
+ LIST_HEAD(list);
+
+ /* Protect against ISR */
+ spin_lock_irq(&schan->chan_lock);
+ ops->halt_channel(schan);
+ spin_unlock_irq(&schan->chan_lock);
+
+ /* Now no new interrupts will occur */
+
+ /* Prepared and not submitted descriptors can still be on the queue */
+ if (!list_empty(&schan->ld_queue))
+ shdma_chan_ld_cleanup(schan, true);
+
+ if (schan->slave_id >= 0) {
+ /* The caller is holding dma_list_mutex */
+ clear_bit(schan->slave_id, shdma_slave_used);
+ chan->private = NULL;
+ }
+
+ schan->real_slave_id = 0;
+
+ spin_lock_irq(&schan->chan_lock);
+
+ list_splice_init(&schan->ld_free, &list);
+ schan->desc_num = 0;
+
+ spin_unlock_irq(&schan->chan_lock);
+
+ kfree(schan->desc);
+}
+
+/**
+ * shdma_add_desc - get, set up and return one transfer descriptor
+ * @schan: DMA channel
+ * @flags: DMA transfer flags
+ * @dst: destination DMA address, incremented when direction equals
+ * DMA_DEV_TO_MEM or DMA_MEM_TO_MEM
+ * @src: source DMA address, incremented when direction equals
+ * DMA_MEM_TO_DEV or DMA_MEM_TO_MEM
+ * @len: DMA transfer length
+ * @first: if NULL, set to the current descriptor and cookie set to -EBUSY
+ * @direction: needed for slave DMA to decide which address to keep constant,
+ * equals DMA_MEM_TO_MEM for MEMCPY
+ * Returns 0 or an error
+ * Locks: called with desc_lock held
+ */
+static struct shdma_desc *shdma_add_desc(struct shdma_chan *schan,
+ unsigned long flags, dma_addr_t *dst, dma_addr_t *src, size_t *len,
+ struct shdma_desc **first, enum dma_transfer_direction direction)
+{
+ struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
+ const struct shdma_ops *ops = sdev->ops;
+ struct shdma_desc *new;
+ size_t copy_size = *len;
+
+ if (!copy_size)
+ return NULL;
+
+ /* Allocate the link descriptor from the free list */
+ new = shdma_get_desc(schan);
+ if (!new) {
+ dev_err(schan->dev, "No free link descriptor available\n");
+ return NULL;
+ }
+
+ ops->desc_setup(schan, new, *src, *dst, &copy_size);
+
+ if (!*first) {
+ /* First desc */
+ new->async_tx.cookie = -EBUSY;
+ *first = new;
+ } else {
+ /* Other desc - invisible to the user */
+ new->async_tx.cookie = -EINVAL;
+ }
+
+ dev_dbg(schan->dev,
+ "chaining (%zu/%zu)@%pad -> %pad with %p, cookie %d\n",
+ copy_size, *len, src, dst, &new->async_tx,
+ new->async_tx.cookie);
+
+ new->mark = DESC_PREPARED;
+ new->async_tx.flags = flags;
+ new->direction = direction;
+ new->partial = 0;
+
+ *len -= copy_size;
+ if (direction == DMA_MEM_TO_MEM || direction == DMA_MEM_TO_DEV)
+ *src += copy_size;
+ if (direction == DMA_MEM_TO_MEM || direction == DMA_DEV_TO_MEM)
+ *dst += copy_size;
+
+ return new;
+}
+
+/*
+ * shdma_prep_sg - prepare transfer descriptors from an SG list
+ *
+ * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also
+ * converted to scatter-gather to guarantee consistent locking and a correct
+ * list manipulation. For slave DMA direction carries the usual meaning, and,
+ * logically, the SG list is RAM and the addr variable contains slave address,
+ * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_MEM_TO_MEM
+ * and the SG list contains only one element and points at the source buffer.
+ */
+static struct dma_async_tx_descriptor *shdma_prep_sg(struct shdma_chan *schan,
+ struct scatterlist *sgl, unsigned int sg_len, dma_addr_t *addr,
+ enum dma_transfer_direction direction, unsigned long flags, bool cyclic)
+{
+ struct scatterlist *sg;
+ struct shdma_desc *first = NULL, *new = NULL /* compiler... */;
+ LIST_HEAD(tx_list);
+ int chunks = 0;
+ unsigned long irq_flags;
+ int i;
+
+ for_each_sg(sgl, sg, sg_len, i)
+ chunks += DIV_ROUND_UP(sg_dma_len(sg), schan->max_xfer_len);
+
+ /* Have to lock the whole loop to protect against concurrent release */
+ spin_lock_irqsave(&schan->chan_lock, irq_flags);
+
+ /*
+ * Chaining:
+ * first descriptor is what user is dealing with in all API calls, its
+ * cookie is at first set to -EBUSY, at tx-submit to a positive
+ * number
+ * if more than one chunk is needed further chunks have cookie = -EINVAL
+ * the last chunk, if not equal to the first, has cookie = -ENOSPC
+ * all chunks are linked onto the tx_list head with their .node heads
+ * only during this function, then they are immediately spliced
+ * back onto the free list in form of a chain
+ */
+ for_each_sg(sgl, sg, sg_len, i) {
+ dma_addr_t sg_addr = sg_dma_address(sg);
+ size_t len = sg_dma_len(sg);
+
+ if (!len)
+ goto err_get_desc;
+
+ do {
+ dev_dbg(schan->dev, "Add SG #%d@%p[%zu], dma %pad\n",
+ i, sg, len, &sg_addr);
+
+ if (direction == DMA_DEV_TO_MEM)
+ new = shdma_add_desc(schan, flags,
+ &sg_addr, addr, &len, &first,
+ direction);
+ else
+ new = shdma_add_desc(schan, flags,
+ addr, &sg_addr, &len, &first,
+ direction);
+ if (!new)
+ goto err_get_desc;
+
+ new->cyclic = cyclic;
+ if (cyclic)
+ new->chunks = 1;
+ else
+ new->chunks = chunks--;
+ list_add_tail(&new->node, &tx_list);
+ } while (len);
+ }
+
+ if (new != first)
+ new->async_tx.cookie = -ENOSPC;
+
+ /* Put them back on the free list, so, they don't get lost */
+ list_splice_tail(&tx_list, &schan->ld_free);
+
+ spin_unlock_irqrestore(&schan->chan_lock, irq_flags);
+
+ return &first->async_tx;
+
+err_get_desc:
+ list_for_each_entry(new, &tx_list, node)
+ new->mark = DESC_IDLE;
+ list_splice(&tx_list, &schan->ld_free);
+
+ spin_unlock_irqrestore(&schan->chan_lock, irq_flags);
+
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor *shdma_prep_memcpy(
+ struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src,
+ size_t len, unsigned long flags)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+ struct scatterlist sg;
+
+ if (!chan || !len)
+ return NULL;
+
+ BUG_ON(!schan->desc_num);
+
+ sg_init_table(&sg, 1);
+ sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_src)), len,
+ offset_in_page(dma_src));
+ sg_dma_address(&sg) = dma_src;
+ sg_dma_len(&sg) = len;
+
+ return shdma_prep_sg(schan, &sg, 1, &dma_dest, DMA_MEM_TO_MEM,
+ flags, false);
+}
+
+static struct dma_async_tx_descriptor *shdma_prep_slave_sg(
+ struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
+ enum dma_transfer_direction direction, unsigned long flags, void *context)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+ struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
+ const struct shdma_ops *ops = sdev->ops;
+ int slave_id = schan->slave_id;
+ dma_addr_t slave_addr;
+
+ if (!chan)
+ return NULL;
+
+ BUG_ON(!schan->desc_num);
+
+ /* Someone calling slave DMA on a generic channel? */
+ if (slave_id < 0 || !sg_len) {
+ dev_warn(schan->dev, "%s: bad parameter: len=%d, id=%d\n",
+ __func__, sg_len, slave_id);
+ return NULL;
+ }
+
+ slave_addr = ops->slave_addr(schan);
+
+ return shdma_prep_sg(schan, sgl, sg_len, &slave_addr,
+ direction, flags, false);
+}
+
+#define SHDMA_MAX_SG_LEN 32
+
+static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic(
+ struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_transfer_direction direction,
+ unsigned long flags)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+ struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
+ struct dma_async_tx_descriptor *desc;
+ const struct shdma_ops *ops = sdev->ops;
+ unsigned int sg_len = buf_len / period_len;
+ int slave_id = schan->slave_id;
+ dma_addr_t slave_addr;
+ struct scatterlist *sgl;
+ int i;
+
+ if (!chan)
+ return NULL;
+
+ BUG_ON(!schan->desc_num);
+
+ if (sg_len > SHDMA_MAX_SG_LEN) {
+ dev_err(schan->dev, "sg length %d exceeds limit %d",
+ sg_len, SHDMA_MAX_SG_LEN);
+ return NULL;
+ }
+
+ /* Someone calling slave DMA on a generic channel? */
+ if (slave_id < 0 || (buf_len < period_len)) {
+ dev_warn(schan->dev,
+ "%s: bad parameter: buf_len=%zu, period_len=%zu, id=%d\n",
+ __func__, buf_len, period_len, slave_id);
+ return NULL;
+ }
+
+ slave_addr = ops->slave_addr(schan);
+
+ /*
+ * Allocate the sg list dynamically as it would consumer too much stack
+ * space.
+ */
+ sgl = kmalloc_array(sg_len, sizeof(*sgl), GFP_KERNEL);
+ if (!sgl)
+ return NULL;
+
+ sg_init_table(sgl, sg_len);
+
+ for (i = 0; i < sg_len; i++) {
+ dma_addr_t src = buf_addr + (period_len * i);
+
+ sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len,
+ offset_in_page(src));
+ sg_dma_address(&sgl[i]) = src;
+ sg_dma_len(&sgl[i]) = period_len;
+ }
+
+ desc = shdma_prep_sg(schan, sgl, sg_len, &slave_addr,
+ direction, flags, true);
+
+ kfree(sgl);
+ return desc;
+}
+
+static int shdma_terminate_all(struct dma_chan *chan)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+ struct shdma_dev *sdev = to_shdma_dev(chan->device);
+ const struct shdma_ops *ops = sdev->ops;
+ unsigned long flags;
+
+ spin_lock_irqsave(&schan->chan_lock, flags);
+ ops->halt_channel(schan);
+
+ if (ops->get_partial && !list_empty(&schan->ld_queue)) {
+ /* Record partial transfer */
+ struct shdma_desc *desc = list_first_entry(&schan->ld_queue,
+ struct shdma_desc, node);
+ desc->partial = ops->get_partial(schan, desc);
+ }
+
+ spin_unlock_irqrestore(&schan->chan_lock, flags);
+
+ shdma_chan_ld_cleanup(schan, true);
+
+ return 0;
+}
+
+static int shdma_config(struct dma_chan *chan,
+ struct dma_slave_config *config)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+
+ /*
+ * So far only .slave_id is used, but the slave drivers are
+ * encouraged to also set a transfer direction and an address.
+ */
+ if (!config)
+ return -EINVAL;
+
+ /*
+ * overriding the slave_id through dma_slave_config is deprecated,
+ * but possibly some out-of-tree drivers still do it.
+ */
+ if (WARN_ON_ONCE(config->slave_id &&
+ config->slave_id != schan->real_slave_id))
+ schan->real_slave_id = config->slave_id;
+
+ /*
+ * We could lock this, but you shouldn't be configuring the
+ * channel, while using it...
+ */
+ return shdma_setup_slave(schan,
+ config->direction == DMA_DEV_TO_MEM ?
+ config->src_addr : config->dst_addr);
+}
+
+static void shdma_issue_pending(struct dma_chan *chan)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+
+ spin_lock_irq(&schan->chan_lock);
+ if (schan->pm_state == SHDMA_PM_ESTABLISHED)
+ shdma_chan_xfer_ld_queue(schan);
+ else
+ schan->pm_state = SHDMA_PM_PENDING;
+ spin_unlock_irq(&schan->chan_lock);
+}
+
+static enum dma_status shdma_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+ enum dma_status status;
+ unsigned long flags;
+
+ shdma_chan_ld_cleanup(schan, false);
+
+ spin_lock_irqsave(&schan->chan_lock, flags);
+
+ status = dma_cookie_status(chan, cookie, txstate);
+
+ /*
+ * If we don't find cookie on the queue, it has been aborted and we have
+ * to report error
+ */
+ if (status != DMA_COMPLETE) {
+ struct shdma_desc *sdesc;
+ status = DMA_ERROR;
+ list_for_each_entry(sdesc, &schan->ld_queue, node)
+ if (sdesc->cookie == cookie) {
+ status = DMA_IN_PROGRESS;
+ break;
+ }
+ }
+
+ spin_unlock_irqrestore(&schan->chan_lock, flags);
+
+ return status;
+}
+
+/* Called from error IRQ or NMI */
+bool shdma_reset(struct shdma_dev *sdev)
+{
+ const struct shdma_ops *ops = sdev->ops;
+ struct shdma_chan *schan;
+ unsigned int handled = 0;
+ int i;
+
+ /* Reset all channels */
+ shdma_for_each_chan(schan, sdev, i) {
+ struct shdma_desc *sdesc;
+ LIST_HEAD(dl);
+
+ if (!schan)
+ continue;
+
+ spin_lock(&schan->chan_lock);
+
+ /* Stop the channel */
+ ops->halt_channel(schan);
+
+ list_splice_init(&schan->ld_queue, &dl);
+
+ if (!list_empty(&dl)) {
+ dev_dbg(schan->dev, "Bring down channel %d\n", schan->id);
+ pm_runtime_put(schan->dev);
+ }
+ schan->pm_state = SHDMA_PM_ESTABLISHED;
+
+ spin_unlock(&schan->chan_lock);
+
+ /* Complete all */
+ list_for_each_entry(sdesc, &dl, node) {
+ struct dma_async_tx_descriptor *tx = &sdesc->async_tx;
+
+ sdesc->mark = DESC_IDLE;
+ dmaengine_desc_get_callback_invoke(tx, NULL);
+ }
+
+ spin_lock(&schan->chan_lock);
+ list_splice(&dl, &schan->ld_free);
+ spin_unlock(&schan->chan_lock);
+
+ handled++;
+ }
+
+ return !!handled;
+}
+EXPORT_SYMBOL(shdma_reset);
+
+static irqreturn_t chan_irq(int irq, void *dev)
+{
+ struct shdma_chan *schan = dev;
+ const struct shdma_ops *ops =
+ to_shdma_dev(schan->dma_chan.device)->ops;
+ irqreturn_t ret;
+
+ spin_lock(&schan->chan_lock);
+
+ ret = ops->chan_irq(schan, irq) ? IRQ_WAKE_THREAD : IRQ_NONE;
+
+ spin_unlock(&schan->chan_lock);
+
+ return ret;
+}
+
+static irqreturn_t chan_irqt(int irq, void *dev)
+{
+ struct shdma_chan *schan = dev;
+ const struct shdma_ops *ops =
+ to_shdma_dev(schan->dma_chan.device)->ops;
+ struct shdma_desc *sdesc;
+
+ spin_lock_irq(&schan->chan_lock);
+ list_for_each_entry(sdesc, &schan->ld_queue, node) {
+ if (sdesc->mark == DESC_SUBMITTED &&
+ ops->desc_completed(schan, sdesc)) {
+ dev_dbg(schan->dev, "done #%d@%p\n",
+ sdesc->async_tx.cookie, &sdesc->async_tx);
+ sdesc->mark = DESC_COMPLETED;
+ break;
+ }
+ }
+ /* Next desc */
+ shdma_chan_xfer_ld_queue(schan);
+ spin_unlock_irq(&schan->chan_lock);
+
+ shdma_chan_ld_cleanup(schan, false);
+
+ return IRQ_HANDLED;
+}
+
+int shdma_request_irq(struct shdma_chan *schan, int irq,
+ unsigned long flags, const char *name)
+{
+ int ret = devm_request_threaded_irq(schan->dev, irq, chan_irq,
+ chan_irqt, flags, name, schan);
+
+ schan->irq = ret < 0 ? ret : irq;
+
+ return ret;
+}
+EXPORT_SYMBOL(shdma_request_irq);
+
+void shdma_chan_probe(struct shdma_dev *sdev,
+ struct shdma_chan *schan, int id)
+{
+ schan->pm_state = SHDMA_PM_ESTABLISHED;
+
+ /* reference struct dma_device */
+ schan->dma_chan.device = &sdev->dma_dev;
+ dma_cookie_init(&schan->dma_chan);
+
+ schan->dev = sdev->dma_dev.dev;
+ schan->id = id;
+
+ if (!schan->max_xfer_len)
+ schan->max_xfer_len = PAGE_SIZE;
+
+ spin_lock_init(&schan->chan_lock);
+
+ /* Init descripter manage list */
+ INIT_LIST_HEAD(&schan->ld_queue);
+ INIT_LIST_HEAD(&schan->ld_free);
+
+ /* Add the channel to DMA device channel list */
+ list_add_tail(&schan->dma_chan.device_node,
+ &sdev->dma_dev.channels);
+ sdev->schan[id] = schan;
+}
+EXPORT_SYMBOL(shdma_chan_probe);
+
+void shdma_chan_remove(struct shdma_chan *schan)
+{
+ list_del(&schan->dma_chan.device_node);
+}
+EXPORT_SYMBOL(shdma_chan_remove);
+
+int shdma_init(struct device *dev, struct shdma_dev *sdev,
+ int chan_num)
+{
+ struct dma_device *dma_dev = &sdev->dma_dev;
+
+ /*
+ * Require all call-backs for now, they can trivially be made optional
+ * later as required
+ */
+ if (!sdev->ops ||
+ !sdev->desc_size ||
+ !sdev->ops->embedded_desc ||
+ !sdev->ops->start_xfer ||
+ !sdev->ops->setup_xfer ||
+ !sdev->ops->set_slave ||
+ !sdev->ops->desc_setup ||
+ !sdev->ops->slave_addr ||
+ !sdev->ops->channel_busy ||
+ !sdev->ops->halt_channel ||
+ !sdev->ops->desc_completed)
+ return -EINVAL;
+
+ sdev->schan = kcalloc(chan_num, sizeof(*sdev->schan), GFP_KERNEL);
+ if (!sdev->schan)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&dma_dev->channels);
+
+ /* Common and MEMCPY operations */
+ dma_dev->device_alloc_chan_resources
+ = shdma_alloc_chan_resources;
+ dma_dev->device_free_chan_resources = shdma_free_chan_resources;
+ dma_dev->device_prep_dma_memcpy = shdma_prep_memcpy;
+ dma_dev->device_tx_status = shdma_tx_status;
+ dma_dev->device_issue_pending = shdma_issue_pending;
+
+ /* Compulsory for DMA_SLAVE fields */
+ dma_dev->device_prep_slave_sg = shdma_prep_slave_sg;
+ dma_dev->device_prep_dma_cyclic = shdma_prep_dma_cyclic;
+ dma_dev->device_config = shdma_config;
+ dma_dev->device_terminate_all = shdma_terminate_all;
+
+ dma_dev->dev = dev;
+
+ return 0;
+}
+EXPORT_SYMBOL(shdma_init);
+
+void shdma_cleanup(struct shdma_dev *sdev)
+{
+ kfree(sdev->schan);
+}
+EXPORT_SYMBOL(shdma_cleanup);
+
+static int __init shdma_enter(void)
+{
+ shdma_slave_used = kcalloc(DIV_ROUND_UP(slave_num, BITS_PER_LONG),
+ sizeof(long),
+ GFP_KERNEL);
+ if (!shdma_slave_used)
+ return -ENOMEM;
+ return 0;
+}
+module_init(shdma_enter);
+
+static void __exit shdma_exit(void)
+{
+ kfree(shdma_slave_used);
+}
+module_exit(shdma_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("SH-DMA driver base library");
+MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");