@@ -97,6 +97,8 @@ struct mmp_pdma_chan {
struct dma_async_tx_descriptor desc;
struct mmp_pdma_phy *phy;
enum dma_transfer_direction dir;
+ struct mmp_pdma_desc_sw *cyclic_first; /* first desc_sw if channel
+ * is in cyclic mode */
/*
* We memorize the original start address of the first descriptor as
* well as the original total length so we can later determine the
@@ -531,6 +533,8 @@ mmp_pdma_prep_memcpy(struct dma_chan *dchan,
new->desc.ddadr = DDADR_STOP;
new->desc.dcmd |= DCMD_ENDIRQEN;
+ chan->cyclic_first = NULL;
+
return &first->async_tx;
fail:
@@ -612,6 +616,96 @@ mmp_pdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
new->desc.ddadr = DDADR_STOP;
new->desc.dcmd |= DCMD_ENDIRQEN;
+ chan->dir = dir;
+ chan->cyclic_first = NULL;
+
+ return &first->async_tx;
+
+fail:
+ if (first)
+ mmp_pdma_free_desc_list(chan, &first->tx_list);
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor *mmp_pdma_prep_dma_cyclic(
+ struct dma_chan *dchan, dma_addr_t buf_addr, size_t len,
+ size_t period_len, enum dma_transfer_direction direction,
+ unsigned long flags, void *context)
+{
+ struct mmp_pdma_chan *chan;
+ struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
+ dma_addr_t dma_src, dma_dst;
+
+ if (!dchan || !len || !period_len)
+ return NULL;
+
+ /* the buffer length must be a multiple of period_len */
+ if (len % period_len != 0)
+ return NULL;
+
+ if (period_len > PDMA_MAX_DESC_BYTES)
+ return NULL;
+
+ chan = to_mmp_pdma_chan(dchan);
+
+ switch (direction) {
+ case DMA_MEM_TO_DEV:
+ dma_src = buf_addr;
+ dma_dst = chan->dev_addr;
+ break;
+ case DMA_DEV_TO_MEM:
+ dma_dst = buf_addr;
+ dma_src = chan->dev_addr;
+ break;
+ default:
+ dev_err(chan->dev, "Unsupported direction for cyclic DMA\n");
+ return NULL;
+ }
+
+ chan->start_addr = buf_addr;
+ chan->total_len = len;
+ chan->dir = direction;
+
+ do {
+ /* Allocate the link descriptor from DMA pool */
+ new = mmp_pdma_alloc_descriptor(chan);
+ if (!new) {
+ dev_err(chan->dev, "no memory for desc\n");
+ goto fail;
+ }
+
+ new->desc.dcmd = chan->dcmd | DCMD_ENDIRQEN |
+ (DCMD_LENGTH & period_len);
+ new->desc.dsadr = dma_src;
+ new->desc.dtadr = dma_dst;
+
+ if (!first)
+ first = new;
+ else
+ prev->desc.ddadr = new->async_tx.phys;
+
+ new->async_tx.cookie = 0;
+ async_tx_ack(&new->async_tx);
+
+ prev = new;
+ len -= period_len;
+
+ if (chan->dir == DMA_MEM_TO_DEV)
+ dma_src += period_len;
+ else
+ dma_dst += period_len;
+
+ /* Insert the link descriptor to the LD ring */
+ list_add_tail(&new->node, &first->tx_list);
+ } while (len);
+
+ first->async_tx.flags = flags; /* client is in control of this ack */
+ first->async_tx.cookie = -EBUSY;
+
+ /* make the cyclic link */
+ new->desc.ddadr = first->async_tx.phys;
+ chan->cyclic_first = first;
+
return &first->async_tx;
fail:
@@ -747,8 +841,25 @@ static void dma_do_tasklet(unsigned long data)
LIST_HEAD(chain_cleanup);
unsigned long flags;
- /* submit pending list; callback for each desc; free desc */
+ if (chan->cyclic_first) {
+ dma_async_tx_callback cb = NULL;
+ void *cb_data = NULL;
+
+ spin_lock_irqsave(&chan->desc_lock, flags);
+ desc = chan->cyclic_first;
+ cb = desc->async_tx.callback;
+ cb_data = desc->async_tx.callback_param;
+ spin_unlock_irqrestore(&chan->desc_lock, flags);
+
+ start_pending_queue(chan);
+ if (cb)
+ cb(cb_data);
+
+ return;
+ }
+
+ /* submit pending list; callback for each desc; free desc */
spin_lock_irqsave(&chan->desc_lock, flags);
/* update the cookie if we have some descriptors to cleanup */
@@ -781,6 +892,7 @@ static void dma_do_tasklet(unsigned long data)
/* Remove from the list of transactions */
list_del(&desc->node);
+
/* Run the link descriptor callback function */
if (txd->callback)
txd->callback(txd->callback_param);
@@ -938,12 +1050,14 @@ static int mmp_pdma_probe(struct platform_device *op)
dma_cap_set(DMA_SLAVE, pdev->device.cap_mask);
dma_cap_set(DMA_MEMCPY, pdev->device.cap_mask);
+ dma_cap_set(DMA_CYCLIC, pdev->device.cap_mask);
pdev->device.dev = &op->dev;
pdev->device.device_alloc_chan_resources = mmp_pdma_alloc_chan_resources;
pdev->device.device_free_chan_resources = mmp_pdma_free_chan_resources;
pdev->device.device_tx_status = mmp_pdma_tx_status;
pdev->device.device_prep_dma_memcpy = mmp_pdma_prep_memcpy;
pdev->device.device_prep_slave_sg = mmp_pdma_prep_slave_sg;
+ pdev->device.device_prep_dma_cyclic = mmp_pdma_prep_dma_cyclic;
pdev->device.device_issue_pending = mmp_pdma_issue_pending;
pdev->device.device_control = mmp_pdma_control;
pdev->device.copy_align = PDMA_ALIGNMENT;
Provide a callback to prepare cyclic DMA transfers. This is for instance needed for audio channel transport. Signed-off-by: Daniel Mack <zonque@gmail.com> --- drivers/dma/mmp_pdma.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 115 insertions(+), 1 deletion(-)