diff options
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/dma-axi-dmac.c | 81 |
1 files changed, 61 insertions, 20 deletions
diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c index ffc0adc2f6ce..0fe3a931d8d5 100644 --- a/drivers/dma/dma-axi-dmac.c +++ b/drivers/dma/dma-axi-dmac.c @@ -166,7 +166,7 @@ static int axi_dmac_dest_is_mem(struct axi_dmac_chan *chan) static bool axi_dmac_check_len(struct axi_dmac_chan *chan, unsigned int len) { - if (len == 0 || len > chan->max_length) + if (len == 0) return false; if ((len & chan->align_mask) != 0) /* Not aligned */ return false; @@ -379,6 +379,49 @@ static struct axi_dmac_desc *axi_dmac_alloc_desc(unsigned int num_sgs) return desc; } +static struct axi_dmac_sg *axi_dmac_fill_linear_sg(struct axi_dmac_chan *chan, + enum dma_transfer_direction direction, dma_addr_t addr, + unsigned int num_periods, unsigned int period_len, + struct axi_dmac_sg *sg) +{ + unsigned int num_segments, i; + unsigned int segment_size; + unsigned int len; + + /* Split into multiple equally sized segments if necessary */ + num_segments = DIV_ROUND_UP(period_len, chan->max_length); + segment_size = DIV_ROUND_UP(period_len, num_segments); + /* Take care of alignment */ + segment_size = ((segment_size - 1) | chan->align_mask) + 1; + + for (i = 0; i < num_periods; i++) { + len = period_len; + + while (len > segment_size) { + if (direction == DMA_DEV_TO_MEM) + sg->dest_addr = addr; + else + sg->src_addr = addr; + sg->x_len = segment_size; + sg->y_len = 1; + sg++; + addr += segment_size; + len -= segment_size; + } + + if (direction == DMA_DEV_TO_MEM) + sg->dest_addr = addr; + else + sg->src_addr = addr; + sg->x_len = len; + sg->y_len = 1; + sg++; + addr += len; + } + + return sg; +} + static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg( struct dma_chan *c, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction direction, @@ -386,16 +429,24 @@ static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg( { struct axi_dmac_chan *chan = to_axi_dmac_chan(c); struct axi_dmac_desc *desc; + struct axi_dmac_sg *dsg; struct scatterlist *sg; + unsigned int num_sgs; unsigned int i; if (direction != chan->direction) return NULL; - desc = axi_dmac_alloc_desc(sg_len); + num_sgs = 0; + for_each_sg(sgl, sg, sg_len, i) + num_sgs += DIV_ROUND_UP(sg_dma_len(sg), chan->max_length); + + desc = axi_dmac_alloc_desc(num_sgs); if (!desc) return NULL; + dsg = desc->sg; + for_each_sg(sgl, sg, sg_len, i) { if (!axi_dmac_check_addr(chan, sg_dma_address(sg)) || !axi_dmac_check_len(chan, sg_dma_len(sg))) { @@ -403,12 +454,8 @@ static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg( return NULL; } - if (direction == DMA_DEV_TO_MEM) - desc->sg[i].dest_addr = sg_dma_address(sg); - else - desc->sg[i].src_addr = sg_dma_address(sg); - desc->sg[i].x_len = sg_dma_len(sg); - desc->sg[i].y_len = 1; + dsg = axi_dmac_fill_linear_sg(chan, direction, sg_dma_address(sg), 1, + sg_dma_len(sg), dsg); } desc->cyclic = false; @@ -423,7 +470,7 @@ static struct dma_async_tx_descriptor *axi_dmac_prep_dma_cyclic( { struct axi_dmac_chan *chan = to_axi_dmac_chan(c); struct axi_dmac_desc *desc; - unsigned int num_periods, i; + unsigned int num_periods, num_segments; if (direction != chan->direction) return NULL; @@ -436,20 +483,14 @@ static struct dma_async_tx_descriptor *axi_dmac_prep_dma_cyclic( return NULL; num_periods = buf_len / period_len; + num_segments = DIV_ROUND_UP(period_len, chan->max_length); - desc = axi_dmac_alloc_desc(num_periods); + desc = axi_dmac_alloc_desc(num_periods * num_segments); if (!desc) return NULL; - for (i = 0; i < num_periods; i++) { - if (direction == DMA_DEV_TO_MEM) - desc->sg[i].dest_addr = buf_addr; - else - desc->sg[i].src_addr = buf_addr; - desc->sg[i].x_len = period_len; - desc->sg[i].y_len = 1; - buf_addr += period_len; - } + axi_dmac_fill_linear_sg(chan, direction, buf_addr, num_periods, + period_len, desc->sg); desc->cyclic = true; @@ -647,7 +688,7 @@ static int axi_dmac_probe(struct platform_device *pdev) of_node_put(of_channels); pdev->dev.dma_parms = &dmac->dma_parms; - dma_set_max_seg_size(&pdev->dev, dmac->chan.max_length); + dma_set_max_seg_size(&pdev->dev, UINT_MAX); dma_dev = &dmac->dma_dev; dma_cap_set(DMA_SLAVE, dma_dev->cap_mask); |