From 9e15db7ce949e9f2d8bb6ce32a74212a4f662370 Mon Sep 17 00:00:00 2001 From: Javier Martin Date: Fri, 2 Mar 2012 09:28:47 +0100 Subject: [PATCH] dmaengine: Add support for multiple descriptors for imx-dma. dmaengine specifies the possibility that several descriptors can be queued for transfer. It also indicates that tasklets must be used for DMA callbacks. Acked-by: Sascha Hauer Signed-off-by: Javier Martin Signed-off-by: Vinod Koul --- drivers/dma/imx-dma.c | 332 ++++++++++++++++++++++++++++++++---------- 1 file changed, 258 insertions(+), 74 deletions(-) diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c index 9a1797873169..85b3d3c21d91 100644 --- a/drivers/dma/imx-dma.c +++ b/drivers/dma/imx-dma.c @@ -5,6 +5,7 @@ * found on i.MX1/21/27 * * Copyright 2010 Sascha Hauer, Pengutronix + * Copyright 2012 Javier Martin, Vista Silicon * * The code contained herein is licensed under the GNU General Public * License. You may obtain a copy of the GNU General Public License @@ -13,6 +14,7 @@ * http://www.opensource.org/licenses/gpl-license.html * http://www.gnu.org/copyleft/gpl.html */ + #include #include #include @@ -29,19 +31,52 @@ #include #include +#define IMXDMA_MAX_CHAN_DESCRIPTORS 16 + +enum imxdma_prep_type { + IMXDMA_DESC_MEMCPY, + IMXDMA_DESC_INTERLEAVED, + IMXDMA_DESC_SLAVE_SG, + IMXDMA_DESC_CYCLIC, +}; + +struct imxdma_desc { + struct list_head node; + struct dma_async_tx_descriptor desc; + enum dma_status status; + dma_addr_t src; + dma_addr_t dest; + size_t len; + unsigned int dmamode; + enum imxdma_prep_type type; + /* For memcpy and interleaved */ + unsigned int config_port; + unsigned int config_mem; + /* For interleaved transfers */ + unsigned int x; + unsigned int y; + unsigned int w; + /* For slave sg and cyclic */ + struct scatterlist *sg; + unsigned int sgcount; +}; + struct imxdma_channel { struct imxdma_engine *imxdma; unsigned int channel; unsigned int imxdma_channel; + struct tasklet_struct dma_tasklet; + struct list_head ld_free; + struct list_head ld_queue; + struct list_head ld_active; + int descs_allocated; enum dma_slave_buswidth word_size; dma_addr_t per_address; u32 watermark_level; struct dma_chan chan; spinlock_t lock; - struct dma_async_tx_descriptor desc; dma_cookie_t last_completed; - enum dma_status status; int dma_request; struct scatterlist *sg_list; }; @@ -60,27 +95,31 @@ static struct imxdma_channel *to_imxdma_chan(struct dma_chan *chan) return container_of(chan, struct imxdma_channel, chan); } -static void imxdma_handle(struct imxdma_channel *imxdmac) +static inline bool imxdma_chan_is_doing_cyclic(struct imxdma_channel *imxdmac) { - if (imxdmac->desc.callback) - imxdmac->desc.callback(imxdmac->desc.callback_param); - imxdmac->last_completed = imxdmac->desc.cookie; + struct imxdma_desc *desc; + + if (!list_empty(&imxdmac->ld_active)) { + desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc, + node); + if (desc->type == IMXDMA_DESC_CYCLIC) + return true; + } + return false; } static void imxdma_irq_handler(int channel, void *data) { struct imxdma_channel *imxdmac = data; - imxdmac->status = DMA_SUCCESS; - imxdma_handle(imxdmac); + tasklet_schedule(&imxdmac->dma_tasklet); } static void imxdma_err_handler(int channel, void *data, int error) { struct imxdma_channel *imxdmac = data; - imxdmac->status = DMA_ERROR; - imxdma_handle(imxdmac); + tasklet_schedule(&imxdmac->dma_tasklet); } static void imxdma_progression(int channel, void *data, @@ -88,8 +127,88 @@ static void imxdma_progression(int channel, void *data, { struct imxdma_channel *imxdmac = data; - imxdmac->status = DMA_SUCCESS; - imxdma_handle(imxdmac); + tasklet_schedule(&imxdmac->dma_tasklet); +} + +static int imxdma_xfer_desc(struct imxdma_desc *d) +{ + struct imxdma_channel *imxdmac = to_imxdma_chan(d->desc.chan); + int ret; + + /* Configure and enable */ + switch (d->type) { + case IMXDMA_DESC_MEMCPY: + ret = imx_dma_config_channel(imxdmac->imxdma_channel, + d->config_port, d->config_mem, 0, 0); + if (ret < 0) + return ret; + ret = imx_dma_setup_single(imxdmac->imxdma_channel, d->src, + d->len, d->dest, d->dmamode); + if (ret < 0) + return ret; + break; + case IMXDMA_DESC_CYCLIC: + ret = imx_dma_setup_progression_handler(imxdmac->imxdma_channel, + imxdma_progression); + if (ret < 0) + return ret; + /* + * We fall through here since cyclic transfer is the same as + * slave_sg adding a progression handler and a specific sg + * configuration which is done in 'imxdma_prep_dma_cyclic'. + */ + case IMXDMA_DESC_SLAVE_SG: + if (d->dmamode == DMA_MODE_READ) + ret = imx_dma_setup_sg(imxdmac->imxdma_channel, d->sg, + d->sgcount, d->len, d->src, d->dmamode); + else + ret = imx_dma_setup_sg(imxdmac->imxdma_channel, d->sg, + d->sgcount, d->len, d->dest, d->dmamode); + if (ret < 0) + return ret; + break; + default: + return -EINVAL; + } + imx_dma_enable(imxdmac->imxdma_channel); + return 0; +} + +static void imxdma_tasklet(unsigned long data) +{ + struct imxdma_channel *imxdmac = (void *)data; + struct imxdma_engine *imxdma = imxdmac->imxdma; + struct imxdma_desc *desc; + + spin_lock(&imxdmac->lock); + + if (list_empty(&imxdmac->ld_active)) { + /* Someone might have called terminate all */ + goto out; + } + desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc, node); + + if (desc->desc.callback) + desc->desc.callback(desc->desc.callback_param); + + imxdmac->last_completed = desc->desc.cookie; + + /* If we are dealing with a cyclic descriptor keep it on ld_active */ + if (imxdma_chan_is_doing_cyclic(imxdmac)) + goto out; + + list_move_tail(imxdmac->ld_active.next, &imxdmac->ld_free); + + if (!list_empty(&imxdmac->ld_queue)) { + desc = list_first_entry(&imxdmac->ld_queue, struct imxdma_desc, + node); + list_move_tail(imxdmac->ld_queue.next, &imxdmac->ld_active); + if (imxdma_xfer_desc(desc) < 0) + dev_warn(imxdma->dev, "%s: channel: %d couldn't xfer desc\n", + __func__, imxdmac->channel); + } +out: + spin_unlock(&imxdmac->lock); } static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, @@ -98,12 +217,17 @@ static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, struct imxdma_channel *imxdmac = to_imxdma_chan(chan); struct dma_slave_config *dmaengine_cfg = (void *)arg; int ret; + unsigned long flags; unsigned int mode = 0; switch (cmd) { case DMA_TERMINATE_ALL: - imxdmac->status = DMA_ERROR; imx_dma_disable(imxdmac->imxdma_channel); + + spin_lock_irqsave(&imxdmac->lock, flags); + list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free); + list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free); + spin_unlock_irqrestore(&imxdmac->lock, flags); return 0; case DMA_SLAVE_CONFIG: if (dmaengine_cfg->direction == DMA_DEV_TO_MEM) { @@ -154,11 +278,14 @@ static enum dma_status imxdma_tx_status(struct dma_chan *chan, struct imxdma_channel *imxdmac = to_imxdma_chan(chan); dma_cookie_t last_used; enum dma_status ret; + unsigned long flags; + spin_lock_irqsave(&imxdmac->lock, flags); last_used = chan->cookie; ret = dma_async_is_complete(cookie, imxdmac->last_completed, last_used); dma_set_tx_state(txstate, imxdmac->last_completed, last_used, 0); + spin_unlock_irqrestore(&imxdmac->lock, flags); return ret; } @@ -171,7 +298,6 @@ static dma_cookie_t imxdma_assign_cookie(struct imxdma_channel *imxdma) cookie = 1; imxdma->chan.cookie = cookie; - imxdma->desc.cookie = cookie; return cookie; } @@ -180,12 +306,15 @@ static dma_cookie_t imxdma_tx_submit(struct dma_async_tx_descriptor *tx) { struct imxdma_channel *imxdmac = to_imxdma_chan(tx->chan); dma_cookie_t cookie; + unsigned long flags; - spin_lock_irq(&imxdmac->lock); + spin_lock_irqsave(&imxdmac->lock, flags); + list_move_tail(imxdmac->ld_free.next, &imxdmac->ld_queue); cookie = imxdma_assign_cookie(imxdmac); + tx->cookie = cookie; - spin_unlock_irq(&imxdmac->lock); + spin_unlock_irqrestore(&imxdmac->lock, flags); return cookie; } @@ -198,21 +327,48 @@ static int imxdma_alloc_chan_resources(struct dma_chan *chan) if (data != NULL) imxdmac->dma_request = data->dma_request; - dma_async_tx_descriptor_init(&imxdmac->desc, chan); - imxdmac->desc.tx_submit = imxdma_tx_submit; - /* txd.flags will be overwritten in prep funcs */ - imxdmac->desc.flags = DMA_CTRL_ACK; + while (imxdmac->descs_allocated < IMXDMA_MAX_CHAN_DESCRIPTORS) { + struct imxdma_desc *desc; - imxdmac->status = DMA_SUCCESS; + desc = kzalloc(sizeof(*desc), GFP_KERNEL); + if (!desc) + break; + __memzero(&desc->desc, sizeof(struct dma_async_tx_descriptor)); + dma_async_tx_descriptor_init(&desc->desc, chan); + desc->desc.tx_submit = imxdma_tx_submit; + /* txd.flags will be overwritten in prep funcs */ + desc->desc.flags = DMA_CTRL_ACK; + desc->status = DMA_SUCCESS; + + list_add_tail(&desc->node, &imxdmac->ld_free); + imxdmac->descs_allocated++; + } - return 0; + if (!imxdmac->descs_allocated) + return -ENOMEM; + + return imxdmac->descs_allocated; } static void imxdma_free_chan_resources(struct dma_chan *chan) { struct imxdma_channel *imxdmac = to_imxdma_chan(chan); + struct imxdma_desc *desc, *_desc; + unsigned long flags; + + spin_lock_irqsave(&imxdmac->lock, flags); imx_dma_disable(imxdmac->imxdma_channel); + list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free); + list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free); + + spin_unlock_irqrestore(&imxdmac->lock, flags); + + list_for_each_entry_safe(desc, _desc, &imxdmac->ld_free, node) { + kfree(desc); + imxdmac->descs_allocated--; + } + INIT_LIST_HEAD(&imxdmac->ld_free); if (imxdmac->sg_list) { kfree(imxdmac->sg_list); @@ -227,23 +383,19 @@ static struct dma_async_tx_descriptor *imxdma_prep_slave_sg( { struct imxdma_channel *imxdmac = to_imxdma_chan(chan); struct scatterlist *sg; - int i, ret, dma_length = 0; - unsigned int dmamode; + int i, dma_length = 0; + struct imxdma_desc *desc; - if (imxdmac->status == DMA_IN_PROGRESS) + if (list_empty(&imxdmac->ld_free) || + imxdma_chan_is_doing_cyclic(imxdmac)) return NULL; - imxdmac->status = DMA_IN_PROGRESS; + desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node); for_each_sg(sgl, sg, sg_len, i) { dma_length += sg->length; } - if (direction == DMA_DEV_TO_MEM) - dmamode = DMA_MODE_READ; - else - dmamode = DMA_MODE_WRITE; - switch (imxdmac->word_size) { case DMA_SLAVE_BUSWIDTH_4_BYTES: if (sgl->length & 3 || sgl->dma_address & 3) @@ -259,12 +411,21 @@ static struct dma_async_tx_descriptor *imxdma_prep_slave_sg( return NULL; } - ret = imx_dma_setup_sg(imxdmac->imxdma_channel, sgl, sg_len, - dma_length, imxdmac->per_address, dmamode); - if (ret) - return NULL; + desc->type = IMXDMA_DESC_SLAVE_SG; + desc->sg = sgl; + desc->sgcount = sg_len; + desc->len = dma_length; + if (direction == DMA_DEV_TO_MEM) { + desc->dmamode = DMA_MODE_READ; + desc->src = imxdmac->per_address; + } else { + desc->dmamode = DMA_MODE_WRITE; + desc->dest = imxdmac->per_address; + } + desc->desc.callback = NULL; + desc->desc.callback_param = NULL; - return &imxdmac->desc; + return &desc->desc; } static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic( @@ -273,23 +434,18 @@ static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic( { struct imxdma_channel *imxdmac = to_imxdma_chan(chan); struct imxdma_engine *imxdma = imxdmac->imxdma; - int i, ret; + struct imxdma_desc *desc; + int i; unsigned int periods = buf_len / period_len; - unsigned int dmamode; dev_dbg(imxdma->dev, "%s channel: %d buf_len=%d period_len=%d\n", __func__, imxdmac->channel, buf_len, period_len); - if (imxdmac->status == DMA_IN_PROGRESS) + if (list_empty(&imxdmac->ld_free) || + imxdma_chan_is_doing_cyclic(imxdmac)) return NULL; - imxdmac->status = DMA_IN_PROGRESS; - ret = imx_dma_setup_progression_handler(imxdmac->imxdma_channel, - imxdma_progression); - if (ret) { - dev_err(imxdma->dev, "Failed to setup the DMA handler\n"); - return NULL; - } + desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node); if (imxdmac->sg_list) kfree(imxdmac->sg_list); @@ -315,17 +471,21 @@ static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic( imxdmac->sg_list[periods].page_link = ((unsigned long)imxdmac->sg_list | 0x01) & ~0x02; - if (direction == DMA_DEV_TO_MEM) - dmamode = DMA_MODE_READ; - else - dmamode = DMA_MODE_WRITE; - - ret = imx_dma_setup_sg(imxdmac->imxdma_channel, imxdmac->sg_list, periods, - IMX_DMA_LENGTH_LOOP, imxdmac->per_address, dmamode); - if (ret) - return NULL; + desc->type = IMXDMA_DESC_CYCLIC; + desc->sg = imxdmac->sg_list; + desc->sgcount = periods; + desc->len = IMX_DMA_LENGTH_LOOP; + if (direction == DMA_DEV_TO_MEM) { + desc->dmamode = DMA_MODE_READ; + desc->src = imxdmac->per_address; + } else { + desc->dmamode = DMA_MODE_WRITE; + desc->dest = imxdmac->per_address; + } + desc->desc.callback = NULL; + desc->desc.callback_param = NULL; - return &imxdmac->desc; + return &desc->desc; } static struct dma_async_tx_descriptor *imxdma_prep_dma_memcpy( @@ -334,36 +494,53 @@ static struct dma_async_tx_descriptor *imxdma_prep_dma_memcpy( { struct imxdma_channel *imxdmac = to_imxdma_chan(chan); struct imxdma_engine *imxdma = imxdmac->imxdma; - int ret; + struct imxdma_desc *desc; dev_dbg(imxdma->dev, "%s channel: %d src=0x%x dst=0x%x len=%d\n", __func__, imxdmac->channel, src, dest, len); - if (imxdmac->status == DMA_IN_PROGRESS) + if (list_empty(&imxdmac->ld_free) || + imxdma_chan_is_doing_cyclic(imxdmac)) return NULL; - imxdmac->status = DMA_IN_PROGRESS; - ret = imx_dma_config_channel(imxdmac->imxdma_channel, - IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR, - IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR, - 0, 0); - if (ret) - return NULL; + desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node); - ret = imx_dma_setup_single(imxdmac->imxdma_channel, src, len, - dest, DMA_MODE_WRITE); - if (ret) - return NULL; + desc->type = IMXDMA_DESC_MEMCPY; + desc->src = src; + desc->dest = dest; + desc->len = len; + desc->dmamode = DMA_MODE_WRITE; + desc->config_port = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR; + desc->config_mem = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR; + desc->desc.callback = NULL; + desc->desc.callback_param = NULL; - return &imxdmac->desc; + return &desc->desc; } static void imxdma_issue_pending(struct dma_chan *chan) { struct imxdma_channel *imxdmac = to_imxdma_chan(chan); - - if (imxdmac->status == DMA_IN_PROGRESS) - imx_dma_enable(imxdmac->imxdma_channel); + struct imxdma_engine *imxdma = imxdmac->imxdma; + struct imxdma_desc *desc; + unsigned long flags; + + spin_lock_irqsave(&imxdmac->lock, flags); + if (list_empty(&imxdmac->ld_active) && + !list_empty(&imxdmac->ld_queue)) { + desc = list_first_entry(&imxdmac->ld_queue, + struct imxdma_desc, node); + + if (imxdma_xfer_desc(desc) < 0) { + dev_warn(imxdma->dev, + "%s: channel: %d couldn't issue DMA xfer\n", + __func__, imxdmac->channel); + } else { + list_move_tail(imxdmac->ld_queue.next, + &imxdmac->ld_active); + } + } + spin_unlock_irqrestore(&imxdmac->lock, flags); } static int __init imxdma_probe(struct platform_device *pdev) @@ -398,11 +575,18 @@ static int __init imxdma_probe(struct platform_device *pdev) imxdmac->imxdma = imxdma; spin_lock_init(&imxdmac->lock); + INIT_LIST_HEAD(&imxdmac->ld_queue); + INIT_LIST_HEAD(&imxdmac->ld_free); + INIT_LIST_HEAD(&imxdmac->ld_active); + + tasklet_init(&imxdmac->dma_tasklet, imxdma_tasklet, + (unsigned long)imxdmac); imxdmac->chan.device = &imxdma->dma_device; imxdmac->channel = i; /* Add the channel to the DMAC list */ - list_add_tail(&imxdmac->chan.device_node, &imxdma->dma_device.channels); + list_add_tail(&imxdmac->chan.device_node, + &imxdma->dma_device.channels); } imxdma->dev = &pdev->dev; -- 2.20.1