Code reorg for transfer prepare and bus width check to make code cleaner. Signed-off-by: Robin Gong <b38343@xxxxxxxxxxxxx> --- drivers/dma/imx-sdma.c | 127 +++++++++++++++++++++++-------------------------- 1 file changed, 60 insertions(+), 67 deletions(-) diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index 377bb18..f2dee57 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -1026,6 +1026,52 @@ static void sdma_free_chan_resources(struct dma_chan *chan) clk_disable(sdma->clk_ahb); } +static int sdma_transfer_init(struct sdma_channel *sdmac, + enum dma_transfer_direction direction) +{ + int ret = 0; + + sdmac->status = DMA_IN_PROGRESS; + sdmac->buf_tail = 0; + sdmac->flags = 0; + sdmac->direction = direction; + + ret = sdma_load_context(sdmac); + if (ret) + return ret; + + sdmac->chn_count = 0; + + return ret; +} + +static int check_bd_buswidth(struct sdma_buffer_descriptor *bd, + struct sdma_channel *sdmac, int count, + dma_addr_t dma_dst, dma_addr_t dma_src) +{ + int ret = 0; + + switch (sdmac->word_size) { + case DMA_SLAVE_BUSWIDTH_4_BYTES: + bd->mode.command = 0; + if ((count | dma_dst | dma_src) & 3) + ret = -EINVAL; + break; + case DMA_SLAVE_BUSWIDTH_2_BYTES: + bd->mode.command = 2; + if ((count | dma_dst | dma_src) & 1) + ret = -EINVAL; + break; + case DMA_SLAVE_BUSWIDTH_1_BYTE: + bd->mode.command = 1; + break; + default: + return -EINVAL; + } + + return ret; +} + 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) @@ -1034,7 +1080,7 @@ static struct dma_async_tx_descriptor *sdma_prep_memcpy( struct sdma_engine *sdma = sdmac->sdma; int channel = sdmac->channel; size_t count; - int i = 0, param, ret; + int i = 0, param; struct sdma_buffer_descriptor *bd; if (!chan || !len || sdmac->status == DMA_IN_PROGRESS) @@ -1046,21 +1092,12 @@ static struct dma_async_tx_descriptor *sdma_prep_memcpy( goto err_out; } - sdmac->status = DMA_IN_PROGRESS; - - sdmac->buf_tail = 0; - dev_dbg(sdma->dev, "memcpy: %pad->%pad, len=%zu, channel=%d.\n", &dma_src, &dma_dst, len, channel); - sdmac->direction = DMA_MEM_TO_MEM; - - ret = sdma_load_context(sdmac); - if (ret) + if (sdma_transfer_init(sdmac, DMA_MEM_TO_MEM)) goto err_out; - sdmac->chn_count = 0; - do { count = min_t(size_t, len, SDMA_BD_MAX_CNT); bd = &sdmac->bd[i]; @@ -1068,28 +1105,8 @@ static struct dma_async_tx_descriptor *sdma_prep_memcpy( bd->ext_buffer_addr = dma_dst; bd->mode.count = count; - if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES) { - ret = -EINVAL; + if (check_bd_buswidth(bd, sdmac, count, dma_dst, dma_src)) goto err_out; - } - - switch (sdmac->word_size) { - case DMA_SLAVE_BUSWIDTH_4_BYTES: - bd->mode.command = 0; - if ((count | dma_dst | dma_src) & 3) - return NULL; - break; - case DMA_SLAVE_BUSWIDTH_2_BYTES: - bd->mode.command = 2; - if ((count | dma_dst | dma_src) & 1) - return NULL; - break; - case DMA_SLAVE_BUSWIDTH_1_BYTE: - bd->mode.command = 1; - break; - default: - return NULL; - } dma_src += count; dma_dst += count; @@ -1141,21 +1158,10 @@ static struct dma_async_tx_descriptor *sdma_prep_sg( if (sdmac->status == DMA_IN_PROGRESS) return NULL; - sdmac->status = DMA_IN_PROGRESS; - - sdmac->flags = 0; - - sdmac->buf_tail = 0; dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n", src_nents, channel); - sdmac->direction = direction; - - ret = sdma_load_context(sdmac); - if (ret) - goto err_out; - if (src_nents > NUM_BD) { dev_err(sdma->dev, "SDMA channel %d: maximum number of sg exceeded: %d > %d\n", channel, src_nents, NUM_BD); @@ -1163,7 +1169,9 @@ static struct dma_async_tx_descriptor *sdma_prep_sg( goto err_out; } - sdmac->chn_count = 0; + if (sdma_transfer_init(sdmac, direction)) + goto err_out; + for_each_sg(src_sg, sg_src, src_nents, i) { struct sdma_buffer_descriptor *bd = &sdmac->bd[i]; int param; @@ -1187,30 +1195,15 @@ static struct dma_async_tx_descriptor *sdma_prep_sg( bd->mode.count = count; sdmac->chn_count += count; - if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES) { - ret = -EINVAL; + if (direction == DMA_MEM_TO_MEM) + ret = check_bd_buswidth(bd, sdmac, count, + sg_dst->dma_address, + sg_src->dma_address); + else + ret = check_bd_buswidth(bd, sdmac, count, 0, + sg_src->dma_address); + if (ret) goto err_out; - } - - switch (sdmac->word_size) { - case DMA_SLAVE_BUSWIDTH_4_BYTES: - bd->mode.command = 0; - if ((count | sg_src->dma_address | (sg_dst && - (sg_dst->dma_address))) & 3) - return NULL; - break; - case DMA_SLAVE_BUSWIDTH_2_BYTES: - bd->mode.command = 2; - if ((count | sg_src->dma_address | - (sg_dst && (sg_dst->dma_address))) & 1) - return NULL; - break; - case DMA_SLAVE_BUSWIDTH_1_BYTE: - bd->mode.command = 1; - break; - default: - return NULL; - } param = BD_DONE | BD_EXTD | BD_CONT; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html