@@ -60,6 +60,7 @@
struct edma_desc {
struct virt_dma_desc vdesc;
struct list_head node;
+ int cyclic;
int absync;
int pset_nr;
int processed;
@@ -173,8 +174,13 @@ static void edma_execute(struct edma_chan *echan)
* then setup a link to the dummy slot, this results in all future
* events being absorbed and that's OK because we're done
*/
- if (edesc->processed == edesc->pset_nr)
- edma_link(echan->slot[nslots-1], echan->ecc->dummy_slot);
+ if (edesc->processed == edesc->pset_nr) {
+ if (edesc->cyclic)
+ edma_link(echan->slot[nslots-1], echan->slot[1]);
+ else
+ edma_link(echan->slot[nslots-1],
+ echan->ecc->dummy_slot);
+ }
edma_resume(echan->ch_num);
@@ -456,6 +462,138 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
}
+static struct dma_async_tx_descriptor *edma_prep_dma_cyclic(
+ struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_transfer_direction direction,
+ unsigned long tx_flags, void *context)
+{
+ struct edma_chan *echan = to_edma_chan(chan);
+ struct device *dev = chan->device->dev;
+ struct edma_desc *edesc;
+ dma_addr_t src_addr, dst_addr;
+ enum dma_slave_buswidth dev_width;
+ u32 burst;
+ int i, ret, nslots;
+
+ if (unlikely(!echan || !buf_len || !period_len))
+ return NULL;
+
+ if (direction == DMA_DEV_TO_MEM) {
+ src_addr = echan->cfg.src_addr;
+ dst_addr = buf_addr;
+ dev_width = echan->cfg.src_addr_width;
+ burst = echan->cfg.src_maxburst;
+ } else if (direction == DMA_MEM_TO_DEV) {
+ src_addr = buf_addr;
+ dst_addr = echan->cfg.dst_addr;
+ dev_width = echan->cfg.dst_addr_width;
+ burst = echan->cfg.dst_maxburst;
+ } else {
+ dev_err(dev, "%s: bad direction?\n", __func__);
+ return NULL;
+ }
+
+ if (dev_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) {
+ dev_err(dev, "Undefined slave buswidth\n");
+ return NULL;
+ }
+
+ if (unlikely(buf_len % period_len)) {
+ dev_err(dev, "Period should be multiple of Buffer length\n");
+ return NULL;
+ }
+
+ nslots = (buf_len / period_len) + 1;
+
+ /*
+ * Cyclic DMA users such as audio cannot tolerate delays introduced
+ * by cases where the number of periods is more than the maximum
+ * number of SGs the EDMA driver can handle at a time. For DMA types
+ * such as Slave SGs, such delays are tolerable and synchronized,
+ * but the synchronization is difficult to achieve with Cyclic and
+ * cannot be guaranteed, so we error out early.
+ */
+ if (nslots > MAX_NR_SG)
+ return NULL;
+
+ edesc = kzalloc(sizeof(*edesc) + nslots *
+ sizeof(edesc->pset[0]), GFP_ATOMIC);
+ if (!edesc) {
+ dev_dbg(dev, "Failed to allocate a descriptor\n");
+ return NULL;
+ }
+
+ edesc->cyclic = 1;
+ edesc->pset_nr = nslots;
+
+ dev_dbg(dev, "%s: nslots=%d\n", __func__, nslots);
+ dev_dbg(dev, "%s: period_len=%d\n", __func__, period_len);
+ dev_dbg(dev, "%s: buf_len=%d\n", __func__, buf_len);
+
+ for (i = 0; i < nslots; i++) {
+ /* Allocate a PaRAM slot, if needed */
+ if (echan->slot[i] < 0) {
+ echan->slot[i] =
+ edma_alloc_slot(EDMA_CTLR(echan->ch_num),
+ EDMA_SLOT_ANY);
+ if (echan->slot[i] < 0) {
+ dev_err(dev, "Failed to allocate slot\n");
+ return NULL;
+ }
+ }
+
+ if (i == nslots - 1) {
+ memcpy(&edesc->pset[i], &edesc->pset[0],
+ sizeof(edesc->pset[0]));
+ break;
+ }
+
+ ret = edma_config_pset(chan, &edesc->pset[i], src_addr,
+ dst_addr, burst, dev_width, period_len,
+ direction);
+ if (ret < 0)
+ return NULL;
+
+ if (direction == DMA_DEV_TO_MEM)
+ dst_addr += period_len;
+ else
+ src_addr += period_len;
+
+ dev_dbg(dev, "%s: Configure period %d of buf:\n", __func__, i);
+ dev_dbg(dev,
+ "\n pset[%d]:\n"
+ " chnum\t%d\n"
+ " slot\t%d\n"
+ " opt\t%08x\n"
+ " src\t%08x\n"
+ " dst\t%08x\n"
+ " abcnt\t%08x\n"
+ " ccnt\t%08x\n"
+ " bidx\t%08x\n"
+ " cidx\t%08x\n"
+ " lkrld\t%08x\n",
+ i, echan->ch_num, echan->slot[i],
+ edesc->pset[i].opt,
+ edesc->pset[i].src,
+ edesc->pset[i].dst,
+ edesc->pset[i].a_b_cnt,
+ edesc->pset[i].ccnt,
+ edesc->pset[i].src_dst_bidx,
+ edesc->pset[i].src_dst_cidx,
+ edesc->pset[i].link_bcntrld);
+
+ edesc->absync = ret;
+
+ /*
+ * Enable interrupts for every period because callback
+ * has to be called for every period.
+ */
+ edesc->pset[i].opt |= TCINTEN;
+ }
+
+ return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
+}
+
static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
{
struct edma_chan *echan = data;
@@ -464,24 +602,28 @@ static void edma_callback(unsigned ch_num, u16 ch_status,
void *data)
unsigned long flags;
struct edmacc_param p;
- /* Pause the channel */
- edma_pause(echan->ch_num);
+ edesc = echan->edesc;
+
+ /* Pause the channel for non-cyclic */
+ if (!edesc || (edesc && !edesc->cyclic))
+ edma_pause(echan->ch_num);
switch (ch_status) {
case DMA_COMPLETE:
spin_lock_irqsave(&echan->vchan.lock, flags);
- edesc = echan->edesc;
if (edesc) {
- if (edesc->processed == edesc->pset_nr) {
+ if (edesc->cyclic) {
+ vchan_cyclic_callback(&edesc->vdesc);
+ } else if (edesc->processed == edesc->pset_nr) {
dev_dbg(dev, "Transfer complete, stopping channel %d\n", ch_num);
edma_stop(echan->ch_num);
vchan_cookie_complete(&edesc->vdesc);
+ edma_execute(echan);
} else {
dev_dbg(dev, "Intermediate transfer complete on channel %d\n", ch_num);
+ edma_execute(echan);
}
-
- edma_execute(echan);
}