[PATCH v1 1/4] dmaengine: imx-sdma: add memcpy interface
From: vkoul@kernel.org (Vinod)
Date: 2018-07-10 15:29:26
Also in:
dmaengine, lkml
Hi Robin, On 11-07-18, 00:23, Robin Gong wrote:
Add MEMCPY support, meanwhile, add SDMA_BD_MAX_CNT instead of '0xffff'.
latter part should be its own patch. Never mix things
+static struct dma_async_tx_descriptor *sdma_prep_memcpy(
+ struct dma_chan *chan, dma_addr_t dma_dst,
+ dma_addr_t dma_src, size_t len, unsigned long flags)
+{
+ struct sdma_channel *sdmac = to_sdma_chan(chan);
+ struct sdma_engine *sdma = sdmac->sdma;
+ int channel = sdmac->channel;
+ size_t count;
+ int i = 0, param;
+ struct sdma_buffer_descriptor *bd;
+ struct sdma_desc *desc;
+
+ if (!chan || !len)
+ return NULL;
+
+ dev_dbg(sdma->dev, "memcpy: %pad->%pad, len=%zu, channel=%d.\n",
+ &dma_src, &dma_dst, len, channel);
+
+ desc = sdma_transfer_init(sdmac, DMA_MEM_TO_MEM, len / SDMA_BD_MAX_CNT
+ + 1);
this looks quite odd to read consider:
esc = sdma_transfer_init(sdmac, DMA_MEM_TO_MEM,
len / SDMA_BD_MAX_CNT + 1);
+ if (!desc)
+ goto err_out;
+
+ do {
+ count = min_t(size_t, len, SDMA_BD_MAX_CNT);
+ bd = &desc->bd[i];
+ bd->buffer_addr = dma_src;
+ bd->ext_buffer_addr = dma_dst;
+ bd->mode.count = count;
+ desc->chn_count += count;
+
+ switch (sdmac->word_size) {
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:This looks wrong, we are in memcpy, there is no SLAVE so no SLAVE widths..
quoted hunk ↗ jump to hunk
static struct dma_async_tx_descriptor *sdma_prep_slave_sg( struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction direction,@@ -1344,9 +1431,9 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg( count = sg_dma_len(sg); - if (count > 0xffff) { + if (count > SDMA_BD_MAX_CNT) { dev_err(sdma->dev, "SDMA channel %d: maximum bytes for sg entry exceeded: %d > %d\n", - channel, count, 0xffff); + channel, count, SDMA_BD_MAX_CNT);
these changes dont belong to this patch
quoted hunk ↗ jump to hunk
@@ -1486,6 +1573,8 @@ static int sdma_config(struct dma_chan *chan, sdmac->watermark_level |= (dmaengine_cfg->dst_maxburst << 16) & SDMA_WATERMARK_LEVEL_HWML; sdmac->word_size = dmaengine_cfg->dst_addr_width; + } else if (dmaengine_cfg->direction == DMA_MEM_TO_MEM) { + sdmac->word_size = dmaengine_cfg->dst_addr_width;
same here too, we are in .device_config which deals with slave. Not memcpy!
quoted hunk ↗ jump to hunk
} else { sdmac->per_address = dmaengine_cfg->dst_addr; sdmac->watermark_level = dmaengine_cfg->dst_maxburst *@@ -1902,6 +1991,7 @@ static int sdma_probe(struct platform_device *pdev) dma_cap_set(DMA_SLAVE, sdma->dma_device.cap_mask); dma_cap_set(DMA_CYCLIC, sdma->dma_device.cap_mask); + dma_cap_set(DMA_MEMCPY, sdma->dma_device.cap_mask); INIT_LIST_HEAD(&sdma->dma_device.channels); /* Initialize channel parameters */@@ -1968,9 +2058,11 @@ static int sdma_probe(struct platform_device *pdev) sdma->dma_device.dst_addr_widths = SDMA_DMA_BUSWIDTHS; sdma->dma_device.directions = SDMA_DMA_DIRECTIONS; sdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT; + sdma->dma_device.device_prep_dma_memcpy = sdma_prep_memcpy; sdma->dma_device.device_issue_pending = sdma_issue_pending; sdma->dma_device.dev->dma_parms = &sdma->dma_parms; - dma_set_max_seg_size(sdma->dma_device.dev, 65535); + sdma->dma_device.copy_align = DMAENGINE_ALIGN_4_BYTES; + dma_set_max_seg_size(sdma->dma_device.dev, SDMA_BD_MAX_CNT);
this line should not be part of this patch -- ~Vinod