diff options
Diffstat (limited to 'drivers/dma/sh/shdma-base.c')
| -rw-r--r-- | drivers/dma/sh/shdma-base.c | 1052 |
1 files changed, 1052 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..158e5e7de --- /dev/null +++ b/drivers/dma/sh/shdma-base.c @@ -0,0 +1,1052 @@ +// 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, ©_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; + + /* + * 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 = bitmap_zalloc(slave_num, GFP_KERNEL); + if (!shdma_slave_used) + return -ENOMEM; + return 0; +} +module_init(shdma_enter); + +static void __exit shdma_exit(void) +{ + bitmap_free(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>"); |