The XDMAC supports interleaved tranfers through its flexible descriptor configuration. Add support for that kind of transfers to the dmaengine driver. Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> --- drivers/dma/at_xdmac.c | 219 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 219 insertions(+) diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 67e566b2b24f..3c40c5ef043d 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -485,6 +485,19 @@ static void at_xdmac_queue_desc(struct dma_chan *chan, __func__, prev, prev->lld.mbr_nda); } +static inline void at_xdmac_increment_block_count(struct dma_chan *chan, + struct at_xdmac_desc *desc) +{ + if (!desc) + return; + + desc->lld.mbr_bc++; + + dev_dbg(chan2dev(chan), + "%s: incrementing the block count of the desc 0x%p\n", + __func__, desc); +} + static struct dma_chan *at_xdmac_xlate(struct of_phandle_args *dma_spec, struct of_dma *of_dma) { @@ -782,6 +795,210 @@ static inline u32 at_xdmac_align_width(struct dma_chan *chan, dma_addr_t addr) return width; } +static struct at_xdmac_desc * +at_xdmac_interleaved_queue_desc(struct dma_chan *chan, + struct at_xdmac_chan *atchan, + struct at_xdmac_desc *prev, + dma_addr_t src, dma_addr_t dst, + struct dma_interleaved_template *xt, + struct data_chunk *chunk) +{ + struct at_xdmac_desc *desc = NULL; + u32 dwidth; + unsigned long flags; + size_t ublen; + /* + * WARNING: The channel configuration is set here since there is no + * dmaengine_slave_config call in this case. Moreover we don't know the + * direction, it involves we can't dynamically set the source and dest + * interface so we have to use the same one. Only interface 0 allows EBI + * access. Hopefully we can access DDR through both ports (at least on + * SAMA5D4x), so we can use the same interface for source and dest, + * that solves the fact we don't know the direction. + */ + u32 chan_cc = AT_XDMAC_CC_DIF(0) + | AT_XDMAC_CC_SIF(0) + | AT_XDMAC_CC_MBSIZE_SIXTEEN + | AT_XDMAC_CC_TYPE_MEM_TRAN; + + dwidth = at_xdmac_align_width(chan, src | dst | chunk->size); + if (chunk->size >= (AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth)) { + dev_dbg(chan2dev(chan), + "%s: chunk too big (%d, max size %lu)...\n", + __func__, chunk->size, + AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth); + return NULL; + } + + if (prev) + dev_dbg(chan2dev(chan), + "Adding items at the end of desc 0x%p\n", prev); + + if (xt->src_inc) { + if (xt->src_sgl) + chan_cc |= AT_XDMAC_CC_SAM_UBS_DS_AM; + else + chan_cc |= AT_XDMAC_CC_SAM_INCREMENTED_AM; + } + + if (xt->dst_inc) { + if (xt->dst_sgl) + chan_cc |= AT_XDMAC_CC_DAM_UBS_DS_AM; + else + chan_cc |= AT_XDMAC_CC_DAM_INCREMENTED_AM; + } + + spin_lock_irqsave(&atchan->lock, flags); + desc = at_xdmac_get_desc(atchan); + spin_unlock_irqrestore(&atchan->lock, flags); + if (!desc) { + dev_err(chan2dev(chan), "can't get descriptor\n"); + return NULL; + } + + chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth); + + ublen = chunk->size >> dwidth; + + desc->lld.mbr_sa = src; + desc->lld.mbr_da = dst; + + if (xt->src_inc && xt->src_sgl) { + if (chunk->src_icg) + desc->lld.mbr_sus = chunk->src_icg; + else + desc->lld.mbr_sus = chunk->icg; + } + + if (xt->dst_inc && xt->dst_sgl) { + if (chunk->dst_icg) + desc->lld.mbr_dus = chunk->dst_icg; + else + desc->lld.mbr_dus = chunk->icg; + } + + desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV3 + | AT_XDMAC_MBR_UBC_NDEN + | AT_XDMAC_MBR_UBC_NSEN + | ublen; + desc->lld.mbr_cfg = chan_cc; + + dev_dbg(chan2dev(chan), + "%s: lld: mbr_sa=0x%08x, mbr_da=0x%08x, mbr_ubc=0x%08x, mbr_cfg=0x%08x\n", + __func__, desc->lld.mbr_sa, desc->lld.mbr_da, + desc->lld.mbr_ubc, desc->lld.mbr_cfg); + + /* Chain lld. */ + if (prev) + at_xdmac_queue_desc(chan, prev, desc); + + return desc; +} + +static struct dma_async_tx_descriptor * +at_xdmac_prep_interleaved(struct dma_chan *chan, + struct dma_interleaved_template *xt, + unsigned long flags) +{ + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan); + struct at_xdmac_desc *prev = NULL, *first = NULL; + struct data_chunk *chunk, *prev_chunk = NULL; + dma_addr_t dst_addr, src_addr; + size_t prev_src_skip = 0, src_skip = 0, len = 0; + size_t prev_dst_skip = 0, dst_skip = 0; + size_t prev_dst_icg = 0, prev_src_icg = 0; + int i; + + if (!xt || (xt->numf != 1) || (xt->dir != DMA_MEM_TO_MEM)) + return NULL; + + dev_dbg(chan2dev(chan), "%s: src=0x%08x, dest=0x%08x, numf=%d, frame_size=%d, flags=0x%lx\n", + __func__, xt->src_start, xt->dst_start, xt->numf, + xt->frame_size, flags); + + src_addr = xt->src_start; + dst_addr = xt->dst_start; + + for (i = 0; i < xt->frame_size; i++) { + struct at_xdmac_desc *desc; + size_t src_icg = 0, dst_icg = 0; + + chunk = xt->sgl + i; + + if (xt->dst_inc) { + if (chunk->dst_icg) + dst_icg = chunk->dst_icg; + else if (xt->dst_sgl) + dst_icg = chunk->icg; + } + + if (xt->src_inc) { + if (chunk->src_icg) + src_icg = chunk->src_icg; + else if (xt->src_sgl) + src_icg = chunk->icg; + } + + src_skip = chunk->size + src_icg; + dst_skip = chunk->size + dst_icg; + + dev_dbg(chan2dev(chan), + "%s: chunk size=%d, src icg=%d, dst icg=%d\n", + __func__, chunk->size, src_icg, dst_icg); + + /* + * Handle the case where we just have the same + * transfer to setup, we can just increase the + * block number and reuse the same descriptor. + */ + if (prev_chunk && prev && + (prev_chunk->size == chunk->size) && + (prev_src_icg == src_icg) && + (prev_dst_icg == dst_icg)) { + dev_dbg(chan2dev(chan), + "%s: same configuration that the previous chunk, merging the descriptors...\n", + __func__); + at_xdmac_increment_block_count(chan, prev); + continue; + } + + desc = at_xdmac_interleaved_queue_desc(chan, atchan, + prev, + src_addr, dst_addr, + xt, chunk); + if (!desc) { + list_splice_init(&first->descs_list, + &atchan->free_descs_list); + return NULL; + } + + if (!first) + first = desc; + + dev_dbg(chan2dev(chan), "%s: add desc 0x%p to descs_list 0x%p\n", + __func__, desc, first); + list_add_tail(&desc->desc_node, &first->descs_list); + + if (xt->src_sgl) + src_addr += src_skip; + + if (xt->dst_sgl) + dst_addr += dst_skip; + + len += chunk->size; + prev_chunk = chunk; + prev_dst_skip = dst_skip; + prev_src_skip = src_skip; + prev = desc; + } + + first->tx_dma_desc.cookie = -EBUSY; + first->tx_dma_desc.flags = flags; + first->xfer_size = len; + + return &first->tx_dma_desc; +} + static struct dma_async_tx_descriptor * at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len, unsigned long flags) @@ -1404,6 +1621,7 @@ static int at_xdmac_probe(struct platform_device *pdev) } dma_cap_set(DMA_CYCLIC, atxdmac->dma.cap_mask); + dma_cap_set(DMA_INTERLEAVE, atxdmac->dma.cap_mask); dma_cap_set(DMA_MEMCPY, atxdmac->dma.cap_mask); dma_cap_set(DMA_SLAVE, atxdmac->dma.cap_mask); /* @@ -1417,6 +1635,7 @@ static int at_xdmac_probe(struct platform_device *pdev) atxdmac->dma.device_tx_status = at_xdmac_tx_status; atxdmac->dma.device_issue_pending = at_xdmac_issue_pending; atxdmac->dma.device_prep_dma_cyclic = at_xdmac_prep_dma_cyclic; + atxdmac->dma.device_prep_interleaved_dma = at_xdmac_prep_interleaved; atxdmac->dma.device_prep_dma_memcpy = at_xdmac_prep_dma_memcpy; atxdmac->dma.device_prep_slave_sg = at_xdmac_prep_slave_sg; atxdmac->dma.device_config = at_xdmac_device_config; -- 2.3.6 -- 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