From: Quanyang Wang <[email protected]>
The dma cyclic mode is required by DP audio, so add it to make DP audio
work.
Reference: b78c51347044 ("dma: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine
driver") from https://github.com/Xilinx/linux-xlnx.git
Signed-off-by: Quanyang Wang <[email protected]>
---
drivers/dma/xilinx/xilinx_dpdma.c | 131 ++++++++++++++++++++++++++++++
1 file changed, 131 insertions(+)
diff --git a/drivers/dma/xilinx/xilinx_dpdma.c
b/drivers/dma/xilinx/xilinx_dpdma.c
index 55df63dead8d..580cd6b8cea3 100644
--- a/drivers/dma/xilinx/xilinx_dpdma.c
+++ b/drivers/dma/xilinx/xilinx_dpdma.c
@@ -499,6 +499,39 @@ static inline void dpdma_set(void __iomem *base, u32
offset, u32 set)
* Descriptor Operations
*/
+/**
+ * xilinx_dpdma_sw_desc_next_32 - Set 32 bit address of a next sw descriptor
+ * @sw_desc: current software descriptor
+ * @next: next descriptor
+ *
+ * Update the current sw descriptor @sw_desc with 32 bit address of the next
+ * descriptor @next.
+ */
+static inline void
+xilinx_dpdma_sw_desc_next_32(struct xilinx_dpdma_sw_desc *sw_desc,
+ struct xilinx_dpdma_sw_desc *next)
+{
+ sw_desc->hw.next_desc = next->dma_addr;
+}
+
+/**
+ * xilinx_dpdma_sw_desc_next_64 - Set 64 bit address of a next sw descriptor
+ * @sw_desc: current software descriptor
+ * @next: next descriptor
+ *
+ * Update the current sw descriptor @sw_desc with 64 bit address of the next
+ * descriptor @next.
+ */
+static inline void
+xilinx_dpdma_sw_desc_next_64(struct xilinx_dpdma_sw_desc *sw_desc,
+ struct xilinx_dpdma_sw_desc *next)
+{
+ sw_desc->hw.next_desc = lower_32_bits(next->dma_addr);
+ sw_desc->hw.addr_ext |= upper_32_bits(next->dma_addr) &
+ XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK;
+}
+
+
/**
* xilinx_dpdma_sw_desc_set_dma_addrs - Set DMA addresses in the descriptor
* @xdev: DPDMA device
@@ -737,6 +770,77 @@ xilinx_dpdma_chan_prep_interleaved_dma(struct
xilinx_dpdma_chan *chan,
return tx_desc;
}
+/**
+ * xilinx_dpdma_chan_prep_cyclic_dma - Prepare a cyclic dma
+ * descriptor
+ * @chan: DPDMA channel
+ * @buf_addr: buffer address
+ * @buf_len: buffer length
+ * @period_len: number of periods
+ *
+ * Prepare a tx descriptor including internal software/hardware descriptors
+ * for the given cyclic transaction.
+ *
+ * Return: A DPDMA TX descriptor on success, or NULL.
+ */
+static struct xilinx_dpdma_tx_desc *
+xilinx_dpdma_chan_prep_cyclic_dma(struct xilinx_dpdma_chan *chan,
+ dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len)
+{
+ struct xilinx_dpdma_tx_desc *tx_desc;
+ struct xilinx_dpdma_sw_desc *sw_desc, *last = NULL;
+ unsigned int periods = buf_len / period_len;
+ unsigned int i;
+
+ tx_desc = xilinx_dpdma_chan_alloc_tx_desc(chan);
+ if (!tx_desc)
+ return NULL;
+
+ for (i = 0; i < periods; i++) {
+ struct xilinx_dpdma_hw_desc *hw_desc;
+
+ if (!IS_ALIGNED(buf_addr, XILINX_DPDMA_ALIGN_BYTES)) {
+ dev_err(chan->xdev->dev, "buffer should be aligned at %d
B\n",
+ XILINX_DPDMA_ALIGN_BYTES);
+ return NULL;
+ }
+
+ sw_desc = xilinx_dpdma_chan_alloc_sw_desc(chan);
+ if (!sw_desc) {
+ xilinx_dpdma_chan_free_tx_desc(&tx_desc->vdesc);
+ return NULL;
+ }
+
+ xilinx_dpdma_sw_desc_set_dma_addrs(chan->xdev, sw_desc, last,
+ &buf_addr, 1);
+ hw_desc = &sw_desc->hw;
+ hw_desc->xfer_size = period_len;
+ hw_desc->hsize_stride =
+ FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK,
period_len) |
+ FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK,
period_len);
+
+ hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_PREEMBLE;
+ hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR;
+ hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE;
+
+ list_add_tail(&sw_desc->node, &tx_desc->descriptors);
+
+ buf_addr += period_len;
+ last = sw_desc;
+ }
+
+ sw_desc = list_first_entry(&tx_desc->descriptors,
+ struct xilinx_dpdma_sw_desc, node);
+ if (chan->xdev->ext_addr)
+ xilinx_dpdma_sw_desc_next_64(last, sw_desc);
+ else
+ xilinx_dpdma_sw_desc_next_32(last, sw_desc);
+ last->hw.control |= XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME;
+
+ return tx_desc;
+}
+
/*
-----------------------------------------------------------------------------
* DPDMA Channel Operations
*/
@@ -1206,6 +1311,31 @@ xilinx_dpdma_prep_interleaved_dma(struct dma_chan *dchan,
return &desc->vdesc.tx;
}
+static struct dma_async_tx_descriptor *
+xilinx_dpdma_prep_cyclic_dma(struct dma_chan *dchan, dma_addr_t buf_addr,
+ size_t buf_len, size_t period_len,
+ enum dma_transfer_direction direction,
+ unsigned long flags)
+{
+ struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
+ struct xilinx_dpdma_tx_desc *desc;
+
+ if (direction != DMA_MEM_TO_DEV)
+ return NULL;
+
+ if (buf_len % period_len)
+ return NULL;
+
+ desc = xilinx_dpdma_chan_prep_cyclic_dma(chan, buf_addr, buf_len,
+ period_len);
+ if (!desc)
+ return NULL;
+
+ vchan_tx_prep(&chan->vchan, &desc->vdesc, flags | DMA_CTRL_ACK);
+
+ return &desc->vdesc.tx;
+}
+
/**
* xilinx_dpdma_alloc_chan_resources - Allocate resources for the channel
* @dchan: DMA channel
@@ -1641,6 +1771,7 @@ static int xilinx_dpdma_probe(struct platform_device
*pdev)
ddev->device_alloc_chan_resources = xilinx_dpdma_alloc_chan_resources;
ddev->device_free_chan_resources = xilinx_dpdma_free_chan_resources;
ddev->device_prep_interleaved_dma = xilinx_dpdma_prep_interleaved_dma;
+ ddev->device_prep_dma_cyclic = xilinx_dpdma_prep_cyclic_dma;
/* TODO: Can we achieve better granularity ? */
ddev->device_tx_status = dma_cookie_status;
ddev->device_issue_pending = xilinx_dpdma_issue_pending;
--
2.25.1
