[PATCH 2/4] dmaengine: vdma: Add support for mulit-channel dma mode

From: Kedareswara rao Appana
Date: Fri Jun 10 2016 - 05:14:51 EST

This patch adds support for AXI DMA multi-channel dma mode
Multichannel mode enables DMA to connect to multiple masters
And slaves on the streaming side.
In Multichannel mode AXI DMA supports 2D transfers.

Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx>
---
drivers/dma/xilinx/xilinx_vdma.c | 242 ++++++++++++++++++++++++++++++++++----
include/linux/dma/xilinx_dma.h | 18 +++
2 files changed, 237 insertions(+), 23 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index 20fe5ea..480b0ba 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -114,7 +114,7 @@
#define XILINX_VDMA_REG_START_ADDRESS_64(n) (0x000c + 8 * (n))

/* HW specific definitions */
-#define XILINX_DMA_MAX_CHANS_PER_DEVICE 0x2
+#define XILINX_DMA_MAX_CHANS_PER_DEVICE 0x20

#define XILINX_DMA_DMAXR_ALL_IRQ_MASK \
(XILINX_DMA_DMASR_FRM_CNT_IRQ | \
@@ -165,6 +165,17 @@
#define XILINX_DMA_COALESCE_MAX 255
#define XILINX_DMA_NUM_APP_WORDS 5

+/* Multi-Channel DMA Descriptor offsets*/
+#define XILINX_DMA_MCRX_CDESC(x) (0x40 + (x-1) * 0x20)
+#define XILINX_DMA_MCRX_TDESC(x) (0x48 + (x-1) * 0x20)
+
+/* Multi-Channel DMA Masks/Shifts */
+#define XILINX_DMA_BD_HSIZE_MASK GENMASK(15, 0)
+#define XILINX_DMA_BD_STRIDE_MASK GENMASK(15, 0)
+#define XILINX_DMA_BD_VSIZE_MASK GENMASK(31, 19)
+#define XILINX_DMA_BD_STRIDE_SHIFT 0
+#define XILINX_DMA_BD_VSIZE_SHIFT 19
+
/* AXI CDMA Specific Registers/Offsets */
#define XILINX_CDMA_REG_SRCADDR 0x18
#define XILINX_CDMA_REG_DSTADDR 0x20
@@ -172,6 +183,13 @@
/* AXI CDMA Specific Masks */
#define XILINX_CDMA_CR_SGMODE BIT(3)

+#define mm2s_mcdmatx_control(tdest, tid, tuser, axcache, aruser) \
+ ((aruser << 28) | (axcache << 24) | \
+ (tuser << 16) | (tid << 8) | (tdest))
+
+#define mm2s_mcdmarx_control(axcache, aruser) \
+ ((aruser << 28) | (axcache << 24))
+
/**
* struct xilinx_vdma_desc_hw - Hardware Descriptor
* @next_desc: Next Descriptor Pointer @0x00
@@ -210,8 +228,8 @@ struct xilinx_axidma_desc_hw {
u32 next_desc_msb;
u32 buf_addr;
u32 buf_addr_msb;
- u32 pad1;
- u32 pad2;
+ u32 mcdma_fields;
+ u32 vsize_stride;
u32 control;
u32 status;
u32 app[XILINX_DMA_NUM_APP_WORDS];
@@ -318,6 +336,7 @@ struct xilinx_dma_tx_descriptor {
* @residue: Residue for AXI DMA
* @seg_v: Statically allocated segments base
* @cyclic_seg_v: Statically allocated segment base for cyclic transfers
+ * @mcdma_config: Device configuration info for MCDMA
* @start_transfer: Differentiate b/w DMA IP's transfer
*/
struct xilinx_dma_chan {
@@ -348,6 +367,7 @@ struct xilinx_dma_chan {
u32 residue;
struct xilinx_axidma_tx_segment *seg_v;
struct xilinx_axidma_tx_segment *cyclic_seg_v;
+ struct xilinx_mcdma_config mcdma_config;
void (*start_transfer)(struct xilinx_dma_chan *chan);
};

@@ -365,6 +385,7 @@ struct xilinx_dma_config {
* @common: DMA device structure
* @chan: Driver specific DMA channel
* @has_sg: Specifies whether Scatter-Gather is present or not
+ * @mcdma: Specifies whether Multi-Channel is present or not
* @flush_on_fsync: Flush on frame sync
* @ext_addr: Indicates 64 bit addressing is supported by dma device
* @pdev: Platform device structure pointer
@@ -374,6 +395,8 @@ struct xilinx_dma_config {
* @txs_clk: DMA mm2s stream clock
* @rx_clk: DMA s2mm clock
* @rxs_clk: DMA s2mm stream clock
+ * @nr_channels: Number of channels DMA device supports
+ * @chan_id: DMA channel identifier
*/
struct xilinx_dma_device {
void __iomem *regs;
@@ -381,6 +404,7 @@ struct xilinx_dma_device {
struct dma_device common;
struct xilinx_dma_chan *chan[XILINX_DMA_MAX_CHANS_PER_DEVICE];
bool has_sg;
+ bool mcdma;
u32 flush_on_fsync;
bool ext_addr;
struct platform_device *pdev;
@@ -390,6 +414,8 @@ struct xilinx_dma_device {
struct clk *txs_clk;
struct clk *rx_clk;
struct clk *rxs_clk;
+ u32 nr_channels;
+ u32 chan_id;
};

/* Macros */
@@ -1174,6 +1200,7 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
{
struct xilinx_dma_tx_descriptor *head_desc, *tail_desc;
struct xilinx_axidma_tx_segment *tail_segment, *old_head, *new_head;
+ struct xilinx_mcdma_config *config = &chan->mcdma_config;
u32 reg;

if (chan->err)
@@ -1196,18 +1223,20 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
tail_segment = list_last_entry(&tail_desc->segments,
struct xilinx_axidma_tx_segment, node);

- old_head = list_first_entry(&head_desc->segments,
- struct xilinx_axidma_tx_segment, node);
- new_head = chan->seg_v;
- /* Copy Buffer Descriptor fields. */
- new_head->hw = old_head->hw;
+ if (chan->has_sg && !chan->xdev->mcdma) {
+ old_head = list_first_entry(&head_desc->segments,
+ struct xilinx_axidma_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;
+ /* 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;
+ tail_segment->hw.next_desc = chan->seg_v->phys;
+ head_desc->async_tx.phys = new_head->phys;
+ }

reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);

@@ -1218,23 +1247,53 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
}

- if (chan->has_sg)
+ if (chan->has_sg && !chan->xdev->mcdma)
xilinx_write(chan, XILINX_DMA_REG_CURDESC,
head_desc->async_tx.phys);

+ if (chan->has_sg && chan->xdev->mcdma) {
+ if (chan->direction == DMA_MEM_TO_DEV) {
+ dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
+ head_desc->async_tx.phys);
+ } else {
+ if (!config->tdest) {
+ dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
+ head_desc->async_tx.phys);
+ } else {
+ dma_ctrl_write(chan,
+ XILINX_DMA_MCRX_CDESC(config->tdest),
+ head_desc->async_tx.phys);
+ }
+ }
+ }
+
xilinx_dma_start(chan);

if (chan->err)
return;

/* Start the transfer */
- if (chan->has_sg) {
+ if (chan->has_sg && !chan->xdev->mcdma) {
if (chan->cyclic)
xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
chan->cyclic_seg_v->phys);
else
xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
tail_segment->phys);
+ } else if (chan->has_sg && chan->xdev->mcdma) {
+ if (chan->direction == DMA_MEM_TO_DEV) {
+ dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
+ tail_segment->phys);
+ } else {
+ if (!config->tdest) {
+ dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
+ tail_segment->phys);
+ } else {
+ dma_ctrl_write(chan,
+ XILINX_DMA_MCRX_TDESC(config->tdest),
+ tail_segment->phys);
+ }
+ }
} else {
struct xilinx_axidma_tx_segment *segment;
struct xilinx_axidma_desc_hw *hw;
@@ -1856,6 +1915,98 @@ error:
}

/**
+ * xilinx_dma_prep_interleaved - prepare a descriptor for a
+ * DMA_SLAVE transaction
+ * @dchan: DMA channel
+ * @xt: Interleaved template pointer
+ * @flags: transfer ack flags
+ *
+ * Return: Async transaction descriptor on success and NULL on failure
+ */
+static struct dma_async_tx_descriptor *
+xilinx_dma_prep_interleaved(struct dma_chan *dchan,
+ struct dma_interleaved_template *xt,
+ unsigned long flags)
+{
+ struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
+ struct xilinx_mcdma_config *config = &chan->mcdma_config;
+ struct xilinx_dma_tx_descriptor *desc;
+ struct xilinx_axidma_tx_segment *segment;
+ struct xilinx_axidma_desc_hw *hw;
+
+ if (!is_slave_direction(xt->dir))
+ return NULL;
+
+ if (!xt->numf || !xt->sgl[0].size)
+ return NULL;
+
+ if (xt->frame_size != 1)
+ return NULL;
+
+ /* Allocate a transaction descriptor. */
+ desc = xilinx_dma_alloc_tx_descriptor(chan);
+ if (!desc)
+ return NULL;
+
+ chan->direction = xt->dir;
+ dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
+ desc->async_tx.tx_submit = xilinx_dma_tx_submit;
+
+ /* Get a free segment */
+ segment = xilinx_axidma_alloc_tx_segment(chan);
+ if (!segment)
+ goto error;
+
+ hw = &segment->hw;
+
+ /* Fill in the descriptor */
+ if (xt->dir != DMA_MEM_TO_DEV) {
+ hw->buf_addr = xt->dst_start;
+ hw->mcdma_fields = mm2s_mcdmarx_control(config->ax_cache,
+ config->ax_user);
+ } else {
+ hw->buf_addr = xt->src_start;
+ hw->mcdma_fields = mm2s_mcdmatx_control(config->tdest,
+ config->tid,
+ config->tuser,
+ config->ax_cache,
+ config->ax_user);
+ }
+
+ hw->vsize_stride = (xt->numf << XILINX_DMA_BD_VSIZE_SHIFT) &
+ XILINX_DMA_BD_VSIZE_MASK;
+ hw->vsize_stride |= (xt->sgl[0].icg + xt->sgl[0].size) &
+ XILINX_DMA_BD_STRIDE_MASK;
+ hw->control = xt->sgl[0].size & XILINX_DMA_BD_HSIZE_MASK;
+
+ /*
+ * Insert the segment into the descriptor segments
+ * list.
+ */
+ list_add_tail(&segment->node, &desc->segments);
+
+
+ segment = list_first_entry(&desc->segments,
+ struct xilinx_axidma_tx_segment, node);
+ desc->async_tx.phys = segment->phys;
+
+ /* For the last DMA_MEM_TO_DEV transfer, set EOP */
+ if (xt->dir == DMA_MEM_TO_DEV) {
+ segment->hw.control |= XILINX_DMA_BD_SOP;
+ segment = list_last_entry(&desc->segments,
+ struct xilinx_axidma_tx_segment,
+ node);
+ segment->hw.control |= XILINX_DMA_BD_EOP;
+ }
+
+ return &desc->async_tx;
+
+error:
+ xilinx_dma_free_tx_descriptor(chan, desc);
+ return NULL;
+}
+
+/**
* xilinx_dma_terminate_all - Halt the channel and free descriptors
* @chan: Driver specific DMA Channel pointer
*/
@@ -1948,6 +2099,21 @@ int xilinx_vdma_channel_set_config(struct dma_chan *dchan,
}
EXPORT_SYMBOL(xilinx_vdma_channel_set_config);

+int xilinx_dma_channel_mcdma_set_config(struct dma_chan *dchan,
+ struct xilinx_mcdma_config *cfg)
+{
+ struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
+
+ chan->mcdma_config.tdest = cfg->tdest;
+ chan->mcdma_config.tid = cfg->tid;
+ chan->mcdma_config.tuser = cfg->tuser;
+ chan->mcdma_config.ax_user = cfg->ax_user;
+ chan->mcdma_config.ax_cache = cfg->ax_cache;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xilinx_dma_channel_mcdma_set_config);
+
/* -----------------------------------------------------------------------------
* Probe and remove
*/
@@ -2170,7 +2336,7 @@ static void xdma_disable_allclks(struct xilinx_dma_device *xdev)
* Return: '0' on success and failure value on error
*/
static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
- struct device_node *node)
+ struct device_node *node, int chan_id)
{
struct xilinx_dma_chan *chan;
bool has_dre = false;
@@ -2214,7 +2380,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,

if (of_device_is_compatible(node, "xlnx,axi-vdma-mm2s-channel")) {
chan->direction = DMA_MEM_TO_DEV;
- chan->id = 0;
+ chan->id = chan_id;

chan->ctrl_offset = XILINX_DMA_MM2S_CTRL_OFFSET;
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
@@ -2227,7 +2393,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
} else if (of_device_is_compatible(node,
"xlnx,axi-vdma-s2mm-channel")) {
chan->direction = DMA_DEV_TO_MEM;
- chan->id = 1;
+ chan->id = chan_id;

chan->ctrl_offset = XILINX_DMA_S2MM_CTRL_OFFSET;
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
@@ -2282,6 +2448,32 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
}

/**
+ * xilinx_dma_child_probe - Per child node probe
+ * It get number of dma-channels per child node from
+ * device-tree and initializes all the channels.
+ *
+ * @xdev: Driver specific device structure
+ * @node: Device node
+ *
+ * Return: 0 always.
+ */
+static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
+ struct device_node *node) {
+ int ret, i, nr_channels = 1;
+
+ ret = of_property_read_u32(node, "dma-channels", &nr_channels);
+ if ((ret < 0) && xdev->mcdma)
+ dev_warn(xdev->dev, "missing dma-channels property\n");
+
+ xdev->nr_channels += nr_channels;
+
+ for (i = 0; i < nr_channels; i++)
+ xilinx_dma_chan_probe(xdev, node, xdev->chan_id++);
+
+ return 0;
+}
+
+/**
* of_dma_xilinx_xlate - Translation function
* @dma_spec: Pointer to DMA specifier as found in the device tree
* @ofdma: Pointer to DMA controller data
@@ -2294,7 +2486,7 @@ static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
struct xilinx_dma_device *xdev = ofdma->of_dma_data;
int chan_id = dma_spec->args[0];

- if (chan_id >= XILINX_DMA_MAX_CHANS_PER_DEVICE || !xdev->chan[chan_id])
+ if (chan_id >= xdev->nr_channels || !xdev->chan[chan_id])
return NULL;

return dma_get_slave_channel(&xdev->chan[chan_id]->common);
@@ -2370,6 +2562,8 @@ static int xilinx_dma_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");
+ if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
+ xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");

if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
err = of_property_read_u32(node, "xlnx,num-fstores",
@@ -2420,6 +2614,8 @@ static int xilinx_dma_probe(struct platform_device *pdev)
xdev->common.device_prep_slave_sg = xilinx_dma_prep_slave_sg;
xdev->common.device_prep_dma_cyclic =
xilinx_dma_prep_dma_cyclic;
+ xdev->common.device_prep_interleaved_dma =
+ xilinx_dma_prep_interleaved;
/* Residue calculation is supported by only AXI DMA */
xdev->common.residue_granularity =
DMA_RESIDUE_GRANULARITY_SEGMENT;
@@ -2435,13 +2631,13 @@ static int xilinx_dma_probe(struct platform_device *pdev)

/* Initialize the channels */
for_each_child_of_node(node, child) {
- err = xilinx_dma_chan_probe(xdev, child);
+ err = xilinx_dma_child_probe(xdev, child);
if (err < 0)
goto disable_clks;
}

if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
- for (i = 0; i < XILINX_DMA_MAX_CHANS_PER_DEVICE; i++)
+ for (i = 0; i < xdev->nr_channels; i++)
if (xdev->chan[i])
xdev->chan[i]->num_frms = num_frames;
}
@@ -2464,7 +2660,7 @@ static int xilinx_dma_probe(struct platform_device *pdev)
disable_clks:
xdma_disable_allclks(xdev);
error:
- for (i = 0; i < XILINX_DMA_MAX_CHANS_PER_DEVICE; i++)
+ for (i = 0; i < xdev->nr_channels; i++)
if (xdev->chan[i])
xilinx_dma_chan_remove(xdev->chan[i]);

@@ -2486,7 +2682,7 @@ static int xilinx_dma_remove(struct platform_device *pdev)

dma_async_device_unregister(&xdev->common);

- for (i = 0; i < XILINX_DMA_MAX_CHANS_PER_DEVICE; i++)
+ for (i = 0; i < xdev->nr_channels; i++)
if (xdev->chan[i])
xilinx_dma_chan_remove(xdev->chan[i]);

diff --git a/include/linux/dma/xilinx_dma.h b/include/linux/dma/xilinx_dma.h
index 7d7312f..dbb05df 100644
--- a/include/linux/dma/xilinx_dma.h
+++ b/include/linux/dma/xilinx_dma.h
@@ -60,6 +60,22 @@ struct zynqmp_dma_config {
};

/**
+ * struct xilinx_mcdma_config - DMA Multi channel configuration structure
+ * @tdest: Channel to operate on
+ * @tid: Channel configuration
+ * @tuser: Tuser configuration
+ * @ax_user: ax_user value
+ * @ax_cache: ax_cache value
+ */
+struct xilinx_mcdma_config {
+ u8 tdest;
+ u8 tid;
+ u8 tuser;
+ u8 ax_user;
+ u8 ax_cache;
+};
+
+/**
* enum xdma_ip_type: DMA IP type.
*
* XDMA_TYPE_AXIDMA: Axi dma ip.
@@ -77,4 +93,6 @@ int xilinx_vdma_channel_set_config(struct dma_chan *dchan,
struct xilinx_vdma_config *cfg);
int zynqmp_dma_channel_set_config(struct dma_chan *dchan,
struct zynqmp_dma_config *cfg);
+int xilinx_dma_channel_mcdma_set_config(struct dma_chan *dchan,
+ struct xilinx_mcdma_config *cfg);
#endif
--
1.7.1