[PATCH 3/7] dmaengine: xilinx_vdma: Add Support for Xilinx AXI Direct Memory Access Engine
Kedareswara rao Appana
appana.durga.rao at xilinx.com
Tue Mar 15 10:23:08 PDT 2016
This patch adds support for the AXI Direct Memory Access (AXI DMA)
core, which is a soft Xilinx IP core that provides high-
bandwidth direct memory access between memory and AXI4-Stream
type target peripherals.
Signed-off-by: Kedareswara rao Appana <appanad at xilinx.com>
---
drivers/dma/xilinx/xilinx_vdma.c | 385 ++++++++++++++++++++++++++++++++++-----
1 file changed, 341 insertions(+), 44 deletions(-)
diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index f682bef..87525a9 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -16,6 +16,12 @@
* video device (S2MM). Initialization, status, interrupt and management
* registers are accessed through an AXI4-Lite slave interface.
*
+ * The AXI DMA, is a soft IP, which provides high-bandwidth Direct Memory
+ * Access between memory and AXI4-Stream-type target peripherals. It can be
+ * configured to have one channel or two channels and if configured as two
+ * channels, one is to transmit data from memory to a device and another is
+ * to receive from a device.
+ *
* 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
@@ -140,6 +146,20 @@
#define XILINX_VDMA_LOOP_COUNT 1000000
#define AXIVDMA_SUPPORT BIT(0)
+#define AXIDMA_SUPPORT BIT(1)
+
+/* AXI DMA Specific Registers/Offsets */
+#define XILINX_DMA_REG_SRCDSTADDR 0x18
+#define XILINX_DMA_REG_DSTADDR 0x20
+#define XILINX_DMA_REG_BTT 0x28
+
+#define XILINX_DMA_MAX_TRANS_LEN GENMASK(22, 0)
+#define XILINX_DMA_CR_COALESCE_MAX GENMASK(23, 16)
+#define XILINX_DMA_CR_COALESCE_SHIFT 16
+#define XILINX_DMA_BD_SOP BIT(27)
+#define XILINX_DMA_BD_EOP BIT(26)
+#define XILINX_DMA_COALESCE_MAX 255
+#define XILINX_DMA_NUM_APP_WORDS 5
/**
* struct xilinx_vdma_desc_hw - Hardware Descriptor
@@ -147,19 +167,23 @@
* @pad1: Reserved @0x04
* @buf_addr: Buffer address @0x08
* @pad2: Reserved @0x0C
- * @vsize: Vertical Size @0x10
+ * @dstaddr_vsize: Vertical Size @0x10
* @hsize: Horizontal Size @0x14
- * @stride: Number of bytes between the first
+ * @control_stride: Number of bytes between the first
* pixels of each horizontal line @0x18
+ * @status: Status field @0x1C
+ * @app: APP Fields @0x20 - 0x30
*/
struct xilinx_vdma_desc_hw {
u32 next_desc;
u32 pad1;
u32 buf_addr;
u32 pad2;
- u32 vsize;
+ u32 dstaddr_vsize;
u32 hsize;
- u32 stride;
+ u32 control_stride;
+ u32 status;
+ u32 app[XILINX_DMA_NUM_APP_WORDS];
} __aligned(64);
/**
@@ -209,6 +233,9 @@ struct xilinx_vdma_tx_descriptor {
* @config: Device configuration info
* @flush_on_fsync: Flush on Frame sync
* @desc_pendingcount: Descriptor pending count
+ * @residue: Residue for AXI DMA
+ * @seg_v: Statically allocated segments base
+ * @start_transfer: Differentiate b/w DMA IP's transfer
*/
struct xilinx_vdma_chan {
struct xilinx_vdma_device *xdev;
@@ -232,6 +259,9 @@ struct xilinx_vdma_chan {
struct xilinx_vdma_config config;
bool flush_on_fsync;
u32 desc_pendingcount;
+ u32 residue;
+ struct xilinx_vdma_tx_segment *seg_v;
+ void (*start_transfer)(struct xilinx_vdma_chan *chan);
};
/**
@@ -436,6 +466,7 @@ static void xilinx_vdma_free_chan_resources(struct dma_chan *dchan)
dev_dbg(chan->dev, "Free all channel resources.\n");
xilinx_vdma_free_descriptors(chan);
+ xilinx_vdma_free_tx_segment(chan, chan->seg_v);
dma_pool_destroy(chan->desc_pool);
chan->desc_pool = NULL;
}
@@ -515,7 +546,12 @@ static int xilinx_vdma_alloc_chan_resources(struct dma_chan *dchan)
return -ENOMEM;
}
+ chan->seg_v = xilinx_vdma_alloc_tx_segment(chan);
dma_cookie_init(dchan);
+
+ /* Enable interrupts */
+ vdma_ctrl_set(chan, XILINX_VDMA_REG_DMACR,
+ XILINX_VDMA_DMAXR_ALL_IRQ_MASK);
return 0;
}
@@ -531,7 +567,37 @@ static enum dma_status xilinx_vdma_tx_status(struct dma_chan *dchan,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
- return dma_cookie_status(dchan, cookie, txstate);
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+ struct xilinx_vdma_tx_descriptor *desc;
+ struct xilinx_vdma_tx_segment *segment;
+ struct xilinx_vdma_desc_hw *hw;
+ enum dma_status ret;
+ unsigned long flags;
+ u32 residue = 0;
+
+ ret = dma_cookie_status(dchan, cookie, txstate);
+ if (ret == DMA_COMPLETE || !txstate)
+ return ret;
+
+ if (chan->xdev->quirks & AXIDMA_SUPPORT) {
+ desc = list_last_entry(&chan->active_list,
+ struct xilinx_vdma_tx_descriptor, node);
+
+ spin_lock_irqsave(&chan->lock, flags);
+ if (chan->has_sg) {
+ list_for_each_entry(segment, &desc->segments, node) {
+ hw = &segment->hw;
+ residue += (hw->control_stride - hw->status) &
+ XILINX_DMA_MAX_TRANS_LEN;
+ }
+ }
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ chan->residue = residue;
+ dma_set_residue(txstate, chan->residue);
+ }
+
+ return ret;
}
/**
@@ -713,8 +779,9 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan)
/* HW expects these parameters to be same for one transaction */
vdma_desc_write(chan, XILINX_VDMA_REG_HSIZE, last->hw.hsize);
vdma_desc_write(chan, XILINX_VDMA_REG_FRMDLY_STRIDE,
- last->hw.stride);
- vdma_desc_write(chan, XILINX_VDMA_REG_VSIZE, last->hw.vsize);
+ last->hw.control_stride);
+ vdma_desc_write(chan, XILINX_VDMA_REG_VSIZE,
+ last->hw.dstaddr_vsize);
}
list_splice_tail_init(&chan->pending_list, &chan->active_list);
@@ -736,6 +803,105 @@ static void xilinx_vdma_issue_pending(struct dma_chan *dchan)
}
/**
+ * xilinx_dma_start_transfer - Starts DMA transfer
+ * @chan: Driver specific channel struct pointer
+ */
+static void xilinx_dma_start_transfer(struct xilinx_vdma_chan *chan)
+{
+ struct xilinx_vdma_tx_descriptor *head_desc, *tail_desc;
+ struct xilinx_vdma_tx_segment *tail_segment, *old_head, *new_head;
+ u32 reg;
+
+ /* This function was invoked with lock held */
+ 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);
+
+ old_head = list_first_entry(&head_desc->segments,
+ struct xilinx_vdma_tx_segment, node);
+ new_head = chan->seg_v;
+ /* Copy Buffer Descriptor fields. */
+ new_head->hw = old_head->hw;
+
+ /* Swap and save new reserve */
+ list_replace_init(&old_head->node, &new_head->node);
+ chan->seg_v = old_head;
+
+ tail_segment->hw.next_desc = chan->seg_v->phys;
+ head_desc->async_tx.phys = new_head->phys;
+
+ /* If it is SG mode and hardware is busy, cannot submit */
+ if (chan->has_sg && xilinx_vdma_is_running(chan) &&
+ !xilinx_vdma_is_idle(chan)) {
+ dev_dbg(chan->dev, "DMA controller still busy\n");
+ return;
+ }
+
+ reg = vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR);
+
+ if (chan->desc_pendingcount <= XILINX_DMA_COALESCE_MAX) {
+ reg &= ~XILINX_DMA_CR_COALESCE_MAX;
+ reg |= chan->desc_pendingcount <<
+ XILINX_DMA_CR_COALESCE_SHIFT;
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_DMACR, reg);
+ }
+
+ if (chan->has_sg)
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_CURDESC,
+ head_desc->async_tx.phys);
+
+ xilinx_vdma_start(chan);
+
+ if (chan->err)
+ return;
+
+ /* Start the transfer */
+ if (chan->has_sg) {
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_TAILDESC,
+ tail_segment->phys);
+ } else {
+ 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);
+
+ /* 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_dma_issue_pending - Issue pending transactions
+ * @dchan: DMA channel
+ */
+static void xilinx_dma_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_dma_start_transfer(chan);
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/**
* xilinx_vdma_complete_descriptor - Mark the active descriptor as complete
* @chan : xilinx DMA channel
*
@@ -841,15 +1007,12 @@ static irqreturn_t xilinx_vdma_irq_handler(int irq, void *data)
vdma_ctrl_write(chan, XILINX_VDMA_REG_DMASR,
errors & XILINX_VDMA_DMASR_ERR_RECOVER_MASK);
- if (!chan->flush_on_fsync ||
- (errors & ~XILINX_VDMA_DMASR_ERR_RECOVER_MASK)) {
- dev_err(chan->dev,
- "Channel %p has errors %x, cdr %x tdr %x\n",
- chan, errors,
- vdma_ctrl_read(chan, XILINX_VDMA_REG_CURDESC),
- vdma_ctrl_read(chan, XILINX_VDMA_REG_TAILDESC));
- chan->err = true;
- }
+ dev_err(chan->dev,
+ "Channel %p has errors %x, cdr %x tdr %x\n",
+ chan, errors,
+ vdma_ctrl_read(chan, XILINX_VDMA_REG_CURDESC),
+ vdma_ctrl_read(chan, XILINX_VDMA_REG_TAILDESC));
+ chan->err = true;
}
if (status & XILINX_VDMA_DMASR_DLY_CNT_IRQ) {
@@ -863,7 +1026,7 @@ static irqreturn_t xilinx_vdma_irq_handler(int irq, void *data)
if (status & XILINX_VDMA_DMASR_FRM_CNT_IRQ) {
spin_lock(&chan->lock);
xilinx_vdma_complete_descriptor(chan);
- xilinx_vdma_start_transfer(chan);
+ chan->start_transfer(chan);
spin_unlock(&chan->lock);
}
@@ -903,7 +1066,8 @@ append:
list_add_tail(&desc->node, &chan->pending_list);
chan->desc_pendingcount++;
- if (unlikely(chan->desc_pendingcount > chan->num_frms)) {
+ if ((unlikely(chan->desc_pendingcount > chan->num_frms)) &&
+ (chan->xdev->quirks & AXIVDMA_SUPPORT)) {
dev_dbg(chan->dev, "desc pendingcount is too high\n");
chan->desc_pendingcount = chan->num_frms;
}
@@ -989,11 +1153,11 @@ xilinx_vdma_dma_prep_interleaved(struct dma_chan *dchan,
/* Fill in the hardware descriptor */
hw = &segment->hw;
- hw->vsize = xt->numf;
+ hw->dstaddr_vsize = xt->numf;
hw->hsize = xt->sgl[0].size;
- hw->stride = (xt->sgl[0].icg + xt->sgl[0].size) <<
+ hw->control_stride = (xt->sgl[0].icg + xt->sgl[0].size) <<
XILINX_VDMA_FRMDLY_STRIDE_STRIDE_SHIFT;
- hw->stride |= chan->config.frm_dly <<
+ hw->control_stride |= chan->config.frm_dly <<
XILINX_VDMA_FRMDLY_STRIDE_FRMDLY_SHIFT;
if (xt->dir != DMA_MEM_TO_DEV)
@@ -1019,6 +1183,108 @@ error:
}
/**
+ * xilinx_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
+ * @dchan: DMA channel
+ * @sgl: scatterlist to transfer to/from
+ * @sg_len: number of entries in @scatterlist
+ * @direction: DMA direction
+ * @flags: transfer ack flags
+ * @context: APP words of the descriptor
+ *
+ * Return: Async transaction descriptor on success and NULL on failure
+ */
+static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
+ struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
+ enum dma_transfer_direction direction, unsigned long flags,
+ void *context)
+{
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+ struct xilinx_vdma_tx_descriptor *desc;
+ struct xilinx_vdma_tx_segment *segment = NULL, *prev = NULL;
+ u32 *app_w = (u32 *)context;
+ struct scatterlist *sg;
+ size_t copy, sg_used;
+ int i;
+
+ if (!is_slave_direction(direction))
+ return NULL;
+
+ /* Allocate a transaction descriptor. */
+ 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;
+
+ /* Build transactions using information in the scatter gather list */
+ for_each_sg(sgl, sg, sg_len, i) {
+ sg_used = 0;
+
+ /* Loop until the entire scatterlist entry is used */
+ while (sg_used < sg_dma_len(sg)) {
+ struct xilinx_vdma_desc_hw *hw;
+
+ /* Get a free segment */
+ segment = xilinx_vdma_alloc_tx_segment(chan);
+ if (!segment)
+ goto error;
+
+ /*
+ * Calculate the maximum number of bytes to transfer,
+ * making sure it is less than the hw limit
+ */
+ copy = min_t(size_t, sg_dma_len(sg) - sg_used,
+ XILINX_DMA_MAX_TRANS_LEN);
+ hw = &segment->hw;
+
+ /* Fill in the descriptor */
+ hw->buf_addr = sg_dma_address(sg) + sg_used;
+
+ hw->control_stride = copy;
+
+ if (chan->direction == DMA_MEM_TO_DEV) {
+ if (app_w)
+ memcpy(hw->app, app_w, sizeof(u32) *
+ XILINX_DMA_NUM_APP_WORDS);
+ }
+
+ if (prev)
+ prev->hw.next_desc = segment->phys;
+
+ prev = segment;
+ sg_used += copy;
+
+ /*
+ * Insert the segment into the descriptor segments
+ * list.
+ */
+ list_add_tail(&segment->node, &desc->segments);
+ }
+ }
+
+ segment = list_first_entry(&desc->segments,
+ struct xilinx_vdma_tx_segment, node);
+ desc->async_tx.phys = segment->phys;
+ prev->hw.next_desc = segment->phys;
+
+ /* For the last DMA_MEM_TO_DEV transfer, set EOP */
+ if (chan->direction == DMA_MEM_TO_DEV) {
+ segment->hw.control_stride |= XILINX_DMA_BD_SOP;
+ segment = list_last_entry(&desc->segments,
+ struct xilinx_vdma_tx_segment,
+ node);
+ segment->hw.control_stride |= XILINX_DMA_BD_EOP;
+ }
+
+ 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
*/
@@ -1179,27 +1445,36 @@ static int xilinx_vdma_chan_probe(struct xilinx_vdma_device *xdev,
chan->id = 0;
chan->ctrl_offset = XILINX_VDMA_MM2S_CTRL_OFFSET;
- chan->desc_offset = XILINX_VDMA_MM2S_DESC_OFFSET;
+ if (xdev->quirks & AXIVDMA_SUPPORT) {
+ chan->desc_offset = XILINX_VDMA_MM2S_DESC_OFFSET;
- if (xdev->flush_on_fsync == XILINX_VDMA_FLUSH_BOTH ||
- xdev->flush_on_fsync == XILINX_VDMA_FLUSH_MM2S)
- chan->flush_on_fsync = true;
+ if (xdev->flush_on_fsync == XILINX_VDMA_FLUSH_BOTH ||
+ xdev->flush_on_fsync == XILINX_VDMA_FLUSH_MM2S)
+ chan->flush_on_fsync = true;
+ }
} else if (of_device_is_compatible(node,
"xlnx,axi-vdma-s2mm-channel")) {
chan->direction = DMA_DEV_TO_MEM;
chan->id = 1;
chan->ctrl_offset = XILINX_VDMA_S2MM_CTRL_OFFSET;
- chan->desc_offset = XILINX_VDMA_S2MM_DESC_OFFSET;
+ if (xdev->quirks & AXIVDMA_SUPPORT) {
+ chan->desc_offset = XILINX_VDMA_S2MM_DESC_OFFSET;
- if (xdev->flush_on_fsync == XILINX_VDMA_FLUSH_BOTH ||
- xdev->flush_on_fsync == XILINX_VDMA_FLUSH_S2MM)
- chan->flush_on_fsync = true;
+ if (xdev->flush_on_fsync == XILINX_VDMA_FLUSH_BOTH ||
+ xdev->flush_on_fsync == XILINX_VDMA_FLUSH_S2MM)
+ chan->flush_on_fsync = true;
+ }
} else {
dev_err(xdev->dev, "Invalid channel compatible node\n");
return -EINVAL;
}
+ if (xdev->quirks & AXIVDMA_SUPPORT)
+ chan->start_transfer = xilinx_vdma_start_transfer;
+ else
+ chan->start_transfer = xilinx_dma_start_transfer;
+
/* Request the interrupt */
chan->irq = irq_of_parse_and_map(node, 0);
err = request_irq(chan->irq, xilinx_vdma_irq_handler, IRQF_SHARED,
@@ -1255,8 +1530,13 @@ static const struct xdma_platform_data xvdma_def = {
.quirks = AXIVDMA_SUPPORT,
};
+static const struct xdma_platform_data xdma_def = {
+ .quirks = AXIDMA_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},
{}
};
MODULE_DEVICE_TABLE(of, xilinx_vdma_of_ids);
@@ -1300,16 +1580,22 @@ static int xilinx_vdma_probe(struct platform_device *pdev)
/* Retrieve the DMA engine properties from the device tree */
xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
- err = of_property_read_u32(node, "xlnx,num-fstores", &num_frames);
- if (err < 0) {
- dev_err(xdev->dev, "missing xlnx,num-fstores property\n");
- return err;
- }
+ if ((xdev->quirks & AXIVDMA_SUPPORT)) {
- err = of_property_read_u32(node, "xlnx,flush-fsync",
- &xdev->flush_on_fsync);
- if (err < 0)
- dev_warn(xdev->dev, "missing xlnx,flush-fsync property\n");
+ err = of_property_read_u32(node, "xlnx,num-fstores",
+ &num_frames);
+ if (err < 0) {
+ dev_err(xdev->dev,
+ "missing xlnx,num-fstores property\n");
+ return err;
+ }
+
+ err = of_property_read_u32(node, "xlnx,flush-fsync",
+ &xdev->flush_on_fsync);
+ if (err < 0)
+ dev_warn(xdev->dev,
+ "missing xlnx,flush-fsync property\n");
+ }
/* Initialize the DMA engine */
xdev->common.dev = &pdev->dev;
@@ -1322,11 +1608,20 @@ static int xilinx_vdma_probe(struct platform_device *pdev)
xilinx_vdma_alloc_chan_resources;
xdev->common.device_free_chan_resources =
xilinx_vdma_free_chan_resources;
- xdev->common.device_prep_interleaved_dma =
- xilinx_vdma_dma_prep_interleaved;
xdev->common.device_terminate_all = xilinx_vdma_terminate_all;
xdev->common.device_tx_status = xilinx_vdma_tx_status;
- xdev->common.device_issue_pending = xilinx_vdma_issue_pending;
+ if (xdev->quirks & AXIVDMA_SUPPORT) {
+ xdev->common.device_issue_pending = xilinx_vdma_issue_pending;
+ xdev->common.device_prep_interleaved_dma =
+ xilinx_vdma_dma_prep_interleaved;
+ } else {
+ 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;
+ }
platform_set_drvdata(pdev, xdev);
@@ -1337,9 +1632,11 @@ static int xilinx_vdma_probe(struct platform_device *pdev)
goto error;
}
- for (i = 0; i < XILINX_VDMA_MAX_CHANS_PER_DEVICE; i++)
- if (xdev->chan[i])
- xdev->chan[i]->num_frms = num_frames;
+ if (xdev->quirks & AXIVDMA_SUPPORT) {
+ for (i = 0; i < XILINX_VDMA_MAX_CHANS_PER_DEVICE; i++)
+ if (xdev->chan[i])
+ xdev->chan[i]->num_frms = num_frames;
+ }
/* Register the DMA engine with the core */
dma_async_device_register(&xdev->common);
--
2.1.2
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