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 | 233 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 233 insertions(+)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 0144a935b8f2..9b602a67d40d 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 +795,224 @@ 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;
+ 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 size_t at_xdmac_get_icg(bool inc, bool sgl, size_t icg, size_t dir_icg)
+{
+ if (inc) {
+ if (dir_icg)
+ return dir_icg;
+ else if (sgl)
+ return icg;
+ }
+
+ return 0;
+}
+
+static size_t at_xdmac_get_dst_icg(struct dma_interleaved_template *xt,
+ struct data_chunk *chunk)
+{
+ return at_xdmac_get_icg(xt->dst_inc, xt->dst_sgl,
+ chunk->icg, chunk->dst_icg);
+}
+
+static size_t at_xdmac_get_src_icg(struct dma_interleaved_template *xt,
+ struct data_chunk *chunk)
+{
+ return at_xdmac_get_icg(xt->src_inc, xt->src_sgl,
+ chunk->icg, chunk->src_icg);
+}
+
+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 dst_skip, src_skip, len = 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, dst_icg;
+
+ chunk = xt->sgl + i;
+
+ dst_icg = at_xdmac_get_dst_icg(xt, chunk);
+ src_icg = at_xdmac_get_src_icg(xt, chunk);
+
+ 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_icg = dst_icg;
+ prev_src_icg = src_icg;
+ 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 +1635,7 @@ 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 +1649,7 @@ 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;
--
2.4.0
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