This patch adds support for the AXI Central Direct Memory Access (AXI
CDMA) core, which is a soft Xilinx IP core that provides high-bandwidth
Direct Memory Access (DMA) between a memory-mapped source address and a
memory-mapped destination address.
Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx>
---
drivers/dma/xilinx/xilinx_vdma.c | 173 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 169 insertions(+), 4 deletions(-)
diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index 87525a9..e6caf79 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -22,6 +22,10 @@
* channels, one is to transmit data from memory to a device and another is
* to receive from a device.
*
+ * The AXI CDMA, is a soft IP, which provides high-bandwidth Direct Memory
+ * Access (DMA) between a memory-mapped source address and a memory-mapped
+ * destination address.
+ *
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
@@ -147,6 +151,7 @@
#define AXIVDMA_SUPPORT BIT(0)
#define AXIDMA_SUPPORT BIT(1)
+#define AXICDMA_SUPPORT BIT(2)
/* AXI DMA Specific Registers/Offsets */
#define XILINX_DMA_REG_SRCDSTADDR 0x18
@@ -161,6 +166,9 @@
#define XILINX_DMA_COALESCE_MAX 255
#define XILINX_DMA_NUM_APP_WORDS 5
+/* AXI CDMA Specific Masks */
+#define XILINX_CDMA_CR_SGMODE BIT(3)
+
/**
* struct xilinx_vdma_desc_hw - Hardware Descriptor
* @next_desc: Next Descriptor Pointer @0x00
@@ -552,6 +560,12 @@ static int xilinx_vdma_alloc_chan_resources(struct dma_chan *dchan)
/* Enable interrupts */
vdma_ctrl_set(chan, XILINX_VDMA_REG_DMACR,
XILINX_VDMA_DMAXR_ALL_IRQ_MASK);
+
+ if ((chan->xdev->quirks & AXICDMA_SUPPORT) && chan->has_sg) {
+ vdma_ctrl_set(chan, XILINX_VDMA_REG_DMACR,
+ XILINX_CDMA_CR_SGMODE);
+ }
+
return 0;
}
@@ -674,6 +688,81 @@ static void xilinx_vdma_start(struct xilinx_vdma_chan *chan)
}
/**
+ * xilinx_cdma_start_transfer - Starts cdma transfer
+ * @chan: Driver specific channel struct pointer
+ */
+static void xilinx_cdma_start_transfer(struct xilinx_vdma_chan *chan)
+{
+ struct xilinx_vdma_tx_descriptor *head_desc, *tail_desc;
+ struct xilinx_vdma_tx_segment *tail_segment;
+ u32 ctrl_reg = vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR);
+
+ if (chan->err)
+ return;
+
+ if (list_empty(&chan->pending_list))
+ return;
+
+ head_desc = list_first_entry(&chan->pending_list,
+ struct xilinx_vdma_tx_descriptor, node);
+ tail_desc = list_last_entry(&chan->pending_list,
+ struct xilinx_vdma_tx_descriptor, node);
+ tail_segment = list_last_entry(&tail_desc->segments,
+ struct xilinx_vdma_tx_segment, node);
+
+ if (chan->desc_pendingcount <= XILINX_DMA_COALESCE_MAX) {
+ ctrl_reg &= ~XILINX_DMA_CR_COALESCE_MAX;
+ ctrl_reg |= chan->desc_pendingcount <<
+ XILINX_DMA_CR_COALESCE_SHIFT;
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_DMACR, ctrl_reg);
+ }
+
+ if (chan->has_sg) {
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_CURDESC,
+ head_desc->async_tx.phys);
+
+ /* Update tail ptr register which will start the transfer */
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_TAILDESC,
+ tail_segment->phys);
+ } else {
+ /* In simple mode */
+ struct xilinx_vdma_tx_segment *segment;
+ struct xilinx_vdma_desc_hw *hw;
+
+ segment = list_first_entry(&head_desc->segments,
+ struct xilinx_vdma_tx_segment,
+ node);
+
+ hw = &segment->hw;
+
+ vdma_ctrl_write(chan, XILINX_DMA_REG_SRCDSTADDR, hw->buf_addr);
+ vdma_ctrl_write(chan, XILINX_DMA_REG_DSTADDR,
+ hw->dstaddr_vsize);
+
+ /* Start the transfer */
+ vdma_ctrl_write(chan, XILINX_DMA_REG_BTT,
+ hw->control_stride & XILINX_DMA_MAX_TRANS_LEN);
+ }
+
+ list_splice_tail_init(&chan->pending_list, &chan->active_list);
+ chan->desc_pendingcount = 0;
+}
+
+/**
+ * xilinx_cdma_issue_pending - Issue pending transactions
+ * @dchan: DMA channel
+ */
+static void xilinx_cdma_issue_pending(struct dma_chan *dchan)
+{
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ xilinx_cdma_start_transfer(chan);
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/**
* xilinx_vdma_start_transfer - Starts VDMA transfer
* @chan: Driver specific channel struct pointer
*/
@@ -1285,6 +1374,69 @@ error:
}
/**
+ * xilinx_cdma_prep_memcpy - prepare descriptors for a memcpy transaction
+ * @dchan: DMA channel
+ * @dma_dst: destination address
+ * @dma_src: source address
+ * @len: transfer length
+ * @flags: transfer ack flags
+ *
+ * Return: Async transaction descriptor on success and NULL on failure
+ */
+static struct dma_async_tx_descriptor *
+xilinx_cdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst,
+ dma_addr_t dma_src, size_t len, unsigned long flags)
+{
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+ struct xilinx_vdma_desc_hw *hw;
+ struct xilinx_vdma_tx_descriptor *desc;
+ struct xilinx_vdma_tx_segment *segment, *prev;
+
+ if (!len || len > XILINX_DMA_MAX_TRANS_LEN)
+ return NULL;
+
+ desc = xilinx_vdma_alloc_tx_descriptor(chan);
+ if (!desc)
+ return NULL;
+
+ dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
+ desc->async_tx.tx_submit = xilinx_vdma_tx_submit;
+ async_tx_ack(&desc->async_tx);
+
+ /* Allocate the link descriptor from DMA pool */
+ segment = xilinx_vdma_alloc_tx_segment(chan);
+ if (!segment)
+ goto error;
+
+ hw = &segment->hw;
+ hw->control_stride = len;
+ hw->buf_addr = dma_src;
+ hw->dstaddr_vsize = dma_dst;
+
+ /* Fill the previous next descriptor with current */
+ prev = list_last_entry(&desc->segments,
+ struct xilinx_vdma_tx_segment, node);
+ prev->hw.next_desc = segment->phys;
+
+ /* Insert the segment into the descriptor segments list. */
+ list_add_tail(&segment->node, &desc->segments);
+
+ prev = segment;
+
+ /* Link the last hardware descriptor with the first. */
+ segment = list_first_entry(&desc->segments,
+ struct xilinx_vdma_tx_segment, node);
+ desc->async_tx.phys = segment->phys;
+ prev->hw.next_desc = segment->phys;
+
+ return &desc->async_tx;
+
+error:
+ xilinx_vdma_free_tx_descriptor(chan, desc);
+ return NULL;
+}
+
+/**
* xilinx_vdma_terminate_all - Halt the channel and free descriptors
* @chan: Driver specific VDMA Channel pointer
*/
@@ -1472,8 +1624,10 @@ static int xilinx_vdma_chan_probe(struct xilinx_vdma_device *xdev,
if (xdev->quirks & AXIVDMA_SUPPORT)
chan->start_transfer = xilinx_vdma_start_transfer;
- else
+ else if (xdev->quirks & AXIDMA_SUPPORT)
chan->start_transfer = xilinx_dma_start_transfer;
+ else
+ chan->start_transfer = xilinx_cdma_start_transfer;
/* Request the interrupt */
chan->irq = irq_of_parse_and_map(node, 0);
@@ -1534,9 +1688,14 @@ static const struct xdma_platform_data xdma_def = {
.quirks = AXIDMA_SUPPORT,
};
+static const struct xdma_platform_data xcdma_def = {
+ .quirks = AXICDMA_SUPPORT,
+};
+
static const struct of_device_id xilinx_vdma_of_ids[] = {
{ .compatible = "xlnx,axi-vdma-1.00.a", .data = &xvdma_def},
{ .compatible = "xlnx,axi-dma-1.00.a", .data = &xdma_def},
+ { .compatible = "xlnx,axi-cdma-1.00.a", .data = &xcdma_def},
{}
};
MODULE_DEVICE_TABLE(of, xilinx_vdma_of_ids);
@@ -1601,8 +1760,10 @@ static int xilinx_vdma_probe(struct platform_device *pdev)
xdev->common.dev = &pdev->dev;
INIT_LIST_HEAD(&xdev->common.channels);
- dma_cap_set(DMA_SLAVE, xdev->common.cap_mask);
- dma_cap_set(DMA_PRIVATE, xdev->common.cap_mask);
+ if (!(xdev->quirks & AXICDMA_SUPPORT)) {
+ dma_cap_set(DMA_SLAVE, xdev->common.cap_mask);
+ dma_cap_set(DMA_PRIVATE, xdev->common.cap_mask);
+ }
xdev->common.device_alloc_chan_resources =
xilinx_vdma_alloc_chan_resources;
@@ -1614,13 +1775,17 @@ static int xilinx_vdma_probe(struct platform_device *pdev)
xdev->common.device_issue_pending = xilinx_vdma_issue_pending;
xdev->common.device_prep_interleaved_dma =
xilinx_vdma_dma_prep_interleaved;
- } else {
+ } else if (xdev->quirks & AXIDMA_SUPPORT) {
xdev->common.device_prep_slave_sg = xilinx_dma_prep_slave_sg;
xdev->common.device_issue_pending = xilinx_dma_issue_pending;
xdev->common.directions = BIT(DMA_DEV_TO_MEM) |
BIT(DMA_MEM_TO_DEV);
xdev->common.residue_granularity =
DMA_RESIDUE_GRANULARITY_SEGMENT;
+ } else {
+ dma_cap_set(DMA_MEMCPY, xdev->common.cap_mask);
+ xdev->common.device_prep_dma_memcpy = xilinx_cdma_prep_memcpy;
+ xdev->common.device_issue_pending = xilinx_cdma_issue_pending;
}
platform_set_drvdata(pdev, xdev);
--
2.1.2
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