[PATCH -next 6/6] dmaengine: xilinx_dma: Add Xilinx AXI MCDMA Engine driver support

From: Radhey Shyam Pandey
Date: Tue Oct 22 2019 - 13:00:51 EST


Add support for AXI Multichannel Direct Memory Access (AXI MCDMA)
core, which is a soft Xilinx IP core that provides high-bandwidth
direct memory access between memory and AXI4-Stream target peripherals.
The AXI MCDMA core provides scatter-gather interface with multiple
independent transmit and receive channels. The driver supports
device_prep_slave_sg slave transfer mode.

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxxxxx>
---
Changes since RFC:
Mention that xilinx_mcdma_start_transfer is called with lock held.
Remove bogus empty lines.
Fix xilinx_mcdma_prep_slave_sg indentation.
In mcdma slave_sg function merge chan->direction and app word check.
Reuse axidma s2mm and mm2 channel nodes.
Add MCDA IP description in dma kconfig.
Regression fixes.
---
drivers/dma/Kconfig | 4 +
drivers/dma/xilinx/xilinx_dma.c | 460 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 455 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 59390e8..cc57801 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -655,6 +655,10 @@ config XILINX_DMA
destination address.
AXI DMA engine provides high-bandwidth one dimensional direct
memory access between memory and AXI4-Stream target peripherals.
+ AXI MCDMA engine provides high-bandwidth direct memory access
+ between memory and AXI4-Stream target peripherals. It provides
+ the scatter gather interface with multiple channels independent
+ configuration support.

config XILINX_ZYNQMP_DMA
tristate "Xilinx ZynqMP DMA Engine"
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 25042a9..d24d1a2 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -25,6 +25,12 @@
* 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.
+ *
+ * The AXI Multichannel Direct Memory Access (AXI MCDMA) core is a soft
+ * Xilinx IP that provides high-bandwidth direct memory access between
+ * memory and AXI4-Stream target peripherals. It provides scatter gather
+ * (SG) interface with multiple channels independent configuration support.
+ *
*/

#include <linux/bitops.h>
@@ -116,7 +122,7 @@
#define XILINX_VDMA_ENABLE_VERTICAL_FLIP BIT(0)

/* 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 | \
@@ -179,6 +185,31 @@

#define xilinx_prep_dma_addr_t(addr) \
((dma_addr_t)((u64)addr##_##msb << 32 | (addr)))
+
+/* AXI MCDMA Specific Registers/Offsets */
+#define XILINX_MCDMA_MM2S_CTRL_OFFSET 0x0000
+#define XILINX_MCDMA_S2MM_CTRL_OFFSET 0x0500
+#define XILINX_MCDMA_CHEN_OFFSET 0x0008
+#define XILINX_MCDMA_CH_ERR_OFFSET 0x0010
+#define XILINX_MCDMA_RXINT_SER_OFFSET 0x0020
+#define XILINX_MCDMA_TXINT_SER_OFFSET 0x0028
+#define XILINX_MCDMA_CHAN_CR_OFFSET(x) (0x40 + (x) * 0x40)
+#define XILINX_MCDMA_CHAN_SR_OFFSET(x) (0x44 + (x) * 0x40)
+#define XILINX_MCDMA_CHAN_CDESC_OFFSET(x) (0x48 + (x) * 0x40)
+#define XILINX_MCDMA_CHAN_TDESC_OFFSET(x) (0x50 + (x) * 0x40)
+
+/* AXI MCDMA Specific Masks/Shifts */
+#define XILINX_MCDMA_COALESCE_SHIFT 16
+#define XILINX_MCDMA_COALESCE_MAX 24
+#define XILINX_MCDMA_IRQ_ALL_MASK GENMASK(7, 5)
+#define XILINX_MCDMA_COALESCE_MASK GENMASK(23, 16)
+#define XILINX_MCDMA_CR_RUNSTOP_MASK BIT(0)
+#define XILINX_MCDMA_IRQ_IOC_MASK BIT(5)
+#define XILINX_MCDMA_IRQ_DELAY_MASK BIT(6)
+#define XILINX_MCDMA_IRQ_ERR_MASK BIT(7)
+#define XILINX_MCDMA_BD_EOP BIT(30)
+#define XILINX_MCDMA_BD_SOP BIT(31)
+
/**
* struct xilinx_vdma_desc_hw - Hardware Descriptor
* @next_desc: Next Descriptor Pointer @0x00
@@ -225,6 +256,30 @@ struct xilinx_axidma_desc_hw {
} __aligned(64);

/**
+ * struct xilinx_aximcdma_desc_hw - Hardware Descriptor for AXI MCDMA
+ * @next_desc: Next Descriptor Pointer @0x00
+ * @next_desc_msb: MSB of Next Descriptor Pointer @0x04
+ * @buf_addr: Buffer address @0x08
+ * @buf_addr_msb: MSB of Buffer address @0x0C
+ * @rsvd: Reserved field @0x10
+ * @control: Control Information field @0x14
+ * @status: Status field @0x18
+ * @sideband_status: Status of sideband signals @0x1C
+ * @app: APP Fields @0x20 - 0x30
+ */
+struct xilinx_aximcdma_desc_hw {
+ u32 next_desc;
+ u32 next_desc_msb;
+ u32 buf_addr;
+ u32 buf_addr_msb;
+ u32 rsvd;
+ u32 control;
+ u32 status;
+ u32 sideband_status;
+ u32 app[XILINX_DMA_NUM_APP_WORDS];
+} __aligned(64);
+
+/**
* struct xilinx_cdma_desc_hw - Hardware Descriptor
* @next_desc: Next Descriptor Pointer @0x00
* @next_desc_msb: Next Descriptor Pointer MSB @0x04
@@ -271,6 +326,18 @@ struct xilinx_axidma_tx_segment {
} __aligned(64);

/**
+ * struct xilinx_aximcdma_tx_segment - Descriptor segment
+ * @hw: Hardware descriptor
+ * @node: Node in the descriptor segments list
+ * @phys: Physical address of segment
+ */
+struct xilinx_aximcdma_tx_segment {
+ struct xilinx_aximcdma_desc_hw hw;
+ struct list_head node;
+ dma_addr_t phys;
+} __aligned(64);
+
+/**
* struct xilinx_cdma_tx_segment - Descriptor segment
* @hw: Hardware descriptor
* @node: Node in the descriptor segments list
@@ -329,11 +396,13 @@ struct xilinx_dma_tx_descriptor {
* @ext_addr: Indicates 64 bit addressing is supported by dma channel
* @desc_submitcount: Descriptor h/w submitted count
* @seg_v: Statically allocated segments base
+ * @seg_mv: Statically allocated segments base for MCDMA
* @seg_p: Physical allocated segments base
* @cyclic_seg_v: Statically allocated segment base for cyclic transfers
* @cyclic_seg_p: Physical allocated segments base for cyclic dma
* @start_transfer: Differentiate b/w DMA IP's transfer
* @stop_transfer: Differentiate b/w DMA IP's quiesce
+ * @tdest: TDEST value for mcdma
* @has_vflip: S2MM vertical flip
*/
struct xilinx_dma_chan {
@@ -364,11 +433,13 @@ struct xilinx_dma_chan {
bool ext_addr;
u32 desc_submitcount;
struct xilinx_axidma_tx_segment *seg_v;
+ struct xilinx_aximcdma_tx_segment *seg_mv;
dma_addr_t seg_p;
struct xilinx_axidma_tx_segment *cyclic_seg_v;
dma_addr_t cyclic_seg_p;
void (*start_transfer)(struct xilinx_dma_chan *chan);
int (*stop_transfer)(struct xilinx_dma_chan *chan);
+ u16 tdest;
bool has_vflip;
};

@@ -378,12 +449,14 @@ struct xilinx_dma_chan {
* @XDMA_TYPE_AXIDMA: Axi dma ip.
* @XDMA_TYPE_CDMA: Axi cdma ip.
* @XDMA_TYPE_VDMA: Axi vdma ip.
+ * @XDMA_TYPE_AXIMCDMA: Axi MCDMA ip.
*
*/
enum xdma_ip_type {
XDMA_TYPE_AXIDMA = 0,
XDMA_TYPE_CDMA,
XDMA_TYPE_VDMA,
+ XDMA_TYPE_AXIMCDMA
};

struct xilinx_dma_config {
@@ -412,6 +485,7 @@ struct xilinx_dma_config {
* @nr_channels: Number of channels DMA device supports
* @chan_id: DMA channel identifier
* @max_buffer_len: Max buffer length
+ * @s2mm_index: S2MM channel index
*/
struct xilinx_dma_device {
void __iomem *regs;
@@ -430,6 +504,7 @@ struct xilinx_dma_device {
u32 nr_channels;
u32 chan_id;
u32 max_buffer_len;
+ u32 s2mm_index;
};

/* Macros */
@@ -530,6 +605,18 @@ static inline void xilinx_axidma_buf(struct xilinx_dma_chan *chan,
}
}

+static inline void xilinx_aximcdma_buf(struct xilinx_dma_chan *chan,
+ struct xilinx_aximcdma_desc_hw *hw,
+ dma_addr_t buf_addr, size_t sg_used)
+{
+ if (chan->ext_addr) {
+ hw->buf_addr = lower_32_bits(buf_addr + sg_used);
+ hw->buf_addr_msb = upper_32_bits(buf_addr + sg_used);
+ } else {
+ hw->buf_addr = buf_addr + sg_used;
+ }
+}
+
/* -----------------------------------------------------------------------------
* Descriptors and segments alloc and free
*/
@@ -603,6 +690,30 @@ xilinx_axidma_alloc_tx_segment(struct xilinx_dma_chan *chan)
return segment;
}

+/**
+ * xilinx_aximcdma_alloc_tx_segment - Allocate transaction segment
+ * @chan: Driver specific DMA channel
+ *
+ * Return: The allocated segment on success and NULL on failure.
+ */
+static struct xilinx_aximcdma_tx_segment *
+xilinx_aximcdma_alloc_tx_segment(struct xilinx_dma_chan *chan)
+{
+ struct xilinx_aximcdma_tx_segment *segment = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ if (!list_empty(&chan->free_seg_list)) {
+ segment = list_first_entry(&chan->free_seg_list,
+ struct xilinx_aximcdma_tx_segment,
+ node);
+ list_del(&segment->node);
+ }
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ return segment;
+}
+
static void xilinx_dma_clean_hw_desc(struct xilinx_axidma_desc_hw *hw)
{
u32 next_desc = hw->next_desc;
@@ -614,6 +725,17 @@ static void xilinx_dma_clean_hw_desc(struct xilinx_axidma_desc_hw *hw)
hw->next_desc_msb = next_desc_msb;
}

+static void xilinx_mcdma_clean_hw_desc(struct xilinx_aximcdma_desc_hw *hw)
+{
+ u32 next_desc = hw->next_desc;
+ u32 next_desc_msb = hw->next_desc_msb;
+
+ memset(hw, 0, sizeof(struct xilinx_aximcdma_desc_hw));
+
+ hw->next_desc = next_desc;
+ hw->next_desc_msb = next_desc_msb;
+}
+
/**
* xilinx_dma_free_tx_segment - Free transaction segment
* @chan: Driver specific DMA channel
@@ -628,6 +750,20 @@ static void xilinx_dma_free_tx_segment(struct xilinx_dma_chan *chan,
}

/**
+ * xilinx_mcdma_free_tx_segment - Free transaction segment
+ * @chan: Driver specific DMA channel
+ * @segment: DMA transaction segment
+ */
+static void xilinx_mcdma_free_tx_segment(struct xilinx_dma_chan *chan,
+ struct xilinx_aximcdma_tx_segment *
+ segment)
+{
+ xilinx_mcdma_clean_hw_desc(&segment->hw);
+
+ list_add_tail(&segment->node, &chan->free_seg_list);
+}
+
+/**
* xilinx_cdma_free_tx_segment - Free transaction segment
* @chan: Driver specific DMA channel
* @segment: DMA transaction segment
@@ -681,6 +817,7 @@ xilinx_dma_free_tx_descriptor(struct xilinx_dma_chan *chan,
struct xilinx_vdma_tx_segment *segment, *next;
struct xilinx_cdma_tx_segment *cdma_segment, *cdma_next;
struct xilinx_axidma_tx_segment *axidma_segment, *axidma_next;
+ struct xilinx_aximcdma_tx_segment *aximcdma_segment, *aximcdma_next;

if (!desc)
return;
@@ -696,12 +833,18 @@ xilinx_dma_free_tx_descriptor(struct xilinx_dma_chan *chan,
list_del(&cdma_segment->node);
xilinx_cdma_free_tx_segment(chan, cdma_segment);
}
- } else {
+ } else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
list_for_each_entry_safe(axidma_segment, axidma_next,
&desc->segments, node) {
list_del(&axidma_segment->node);
xilinx_dma_free_tx_segment(chan, axidma_segment);
}
+ } else {
+ list_for_each_entry_safe(aximcdma_segment, aximcdma_next,
+ &desc->segments, node) {
+ list_del(&aximcdma_segment->node);
+ xilinx_mcdma_free_tx_segment(chan, aximcdma_segment);
+ }
}

kfree(desc);
@@ -770,10 +913,23 @@ static void xilinx_dma_free_chan_resources(struct dma_chan *dchan)
chan->cyclic_seg_v, chan->cyclic_seg_p);
}

- if (chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIDMA) {
+ if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA) {
+ spin_lock_irqsave(&chan->lock, flags);
+ INIT_LIST_HEAD(&chan->free_seg_list);
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ /* Free memory that is allocated for BD */
+ dma_free_coherent(chan->dev, sizeof(*chan->seg_mv) *
+ XILINX_DMA_NUM_DESCS, chan->seg_mv,
+ chan->seg_p);
+ }
+
+ if (chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIDMA &&
+ chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIMCDMA) {
dma_pool_destroy(chan->desc_pool);
chan->desc_pool = NULL;
}
+
}

/**
@@ -955,6 +1111,30 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
list_add_tail(&chan->seg_v[i].node,
&chan->free_seg_list);
}
+ } else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA) {
+ /* Allocate the buffer descriptors. */
+ chan->seg_mv = dma_alloc_coherent(chan->dev,
+ sizeof(*chan->seg_mv) *
+ XILINX_DMA_NUM_DESCS,
+ &chan->seg_p, GFP_KERNEL);
+ if (!chan->seg_mv) {
+ dev_err(chan->dev,
+ "unable to allocate channel %d descriptors\n",
+ chan->id);
+ return -ENOMEM;
+ }
+ for (i = 0; i < XILINX_DMA_NUM_DESCS; i++) {
+ chan->seg_mv[i].hw.next_desc =
+ lower_32_bits(chan->seg_p + sizeof(*chan->seg_mv) *
+ ((i + 1) % XILINX_DMA_NUM_DESCS));
+ chan->seg_mv[i].hw.next_desc_msb =
+ upper_32_bits(chan->seg_p + sizeof(*chan->seg_mv) *
+ ((i + 1) % XILINX_DMA_NUM_DESCS));
+ chan->seg_mv[i].phys = chan->seg_p +
+ sizeof(*chan->seg_v) * i;
+ list_add_tail(&chan->seg_mv[i].node,
+ &chan->free_seg_list);
+ }
} else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
chan->desc_pool = dma_pool_create("xilinx_cdma_desc_pool",
chan->dev,
@@ -970,7 +1150,8 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
}

if (!chan->desc_pool &&
- (chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIDMA)) {
+ ((chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIDMA) &&
+ chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIMCDMA)) {
dev_err(chan->dev,
"unable to allocate channel %d descriptor pool\n",
chan->id);
@@ -1368,6 +1549,76 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
}

/**
+ * xilinx_mcdma_start_transfer - Starts MCDMA transfer
+ * @chan: Driver specific channel struct pointer
+ */
+static void xilinx_mcdma_start_transfer(struct xilinx_dma_chan *chan)
+{
+ struct xilinx_dma_tx_descriptor *head_desc, *tail_desc;
+ struct xilinx_axidma_tx_segment *tail_segment;
+ u32 reg;
+
+ /*
+ * lock has been held by calling functions, so we don't need it
+ * to take it here again.
+ */
+
+ if (chan->err)
+ return;
+
+ if (!chan->idle)
+ return;
+
+ if (list_empty(&chan->pending_list))
+ return;
+
+ head_desc = list_first_entry(&chan->pending_list,
+ struct xilinx_dma_tx_descriptor, node);
+ tail_desc = list_last_entry(&chan->pending_list,
+ struct xilinx_dma_tx_descriptor, node);
+ tail_segment = list_last_entry(&tail_desc->segments,
+ struct xilinx_axidma_tx_segment, node);
+
+ reg = dma_ctrl_read(chan, XILINX_MCDMA_CHAN_CR_OFFSET(chan->tdest));
+
+ if (chan->desc_pendingcount <= XILINX_MCDMA_COALESCE_MAX) {
+ reg &= ~XILINX_MCDMA_COALESCE_MASK;
+ reg |= chan->desc_pendingcount <<
+ XILINX_MCDMA_COALESCE_SHIFT;
+ }
+
+ reg |= XILINX_MCDMA_IRQ_ALL_MASK;
+ dma_ctrl_write(chan, XILINX_MCDMA_CHAN_CR_OFFSET(chan->tdest), reg);
+
+ /* Program current descriptor */
+ xilinx_write(chan, XILINX_MCDMA_CHAN_CDESC_OFFSET(chan->tdest),
+ head_desc->async_tx.phys);
+
+ /* Program channel enable register */
+ reg = dma_ctrl_read(chan, XILINX_MCDMA_CHEN_OFFSET);
+ reg |= BIT(chan->tdest);
+ dma_ctrl_write(chan, XILINX_MCDMA_CHEN_OFFSET, reg);
+
+ /* Start the fetch of BDs for the channel */
+ reg = dma_ctrl_read(chan, XILINX_MCDMA_CHAN_CR_OFFSET(chan->tdest));
+ reg |= XILINX_MCDMA_CR_RUNSTOP_MASK;
+ dma_ctrl_write(chan, XILINX_MCDMA_CHAN_CR_OFFSET(chan->tdest), reg);
+
+ xilinx_dma_start(chan);
+
+ if (chan->err)
+ return;
+
+ /* Start the transfer */
+ xilinx_write(chan, XILINX_MCDMA_CHAN_TDESC_OFFSET(chan->tdest),
+ tail_segment->phys);
+
+ list_splice_tail_init(&chan->pending_list, &chan->active_list);
+ chan->desc_pendingcount = 0;
+ chan->idle = false;
+}
+
+/**
* xilinx_dma_issue_pending - Issue pending transactions
* @dchan: DMA channel
*/
@@ -1466,6 +1717,74 @@ static int xilinx_dma_chan_reset(struct xilinx_dma_chan *chan)
}

/**
+ * xilinx_mcdma_irq_handler - MCDMA Interrupt handler
+ * @irq: IRQ number
+ * @data: Pointer to the Xilinx MCDMA channel structure
+ *
+ * Return: IRQ_HANDLED/IRQ_NONE
+ */
+static irqreturn_t xilinx_mcdma_irq_handler(int irq, void *data)
+{
+ struct xilinx_dma_chan *chan = data;
+ u32 status, ser_offset, chan_sermask, chan_offset = 0, chan_id;
+
+ if (chan->direction == DMA_DEV_TO_MEM)
+ ser_offset = XILINX_MCDMA_RXINT_SER_OFFSET;
+ else
+ ser_offset = XILINX_MCDMA_TXINT_SER_OFFSET;
+
+ /* Read the channel id raising the interrupt*/
+ chan_sermask = dma_ctrl_read(chan, ser_offset);
+ chan_id = ffs(chan_sermask);
+
+ if (!chan_id)
+ return IRQ_NONE;
+
+ if (chan->direction == DMA_DEV_TO_MEM)
+ chan_offset = chan->xdev->s2mm_index;
+
+ chan_offset = chan_offset + (chan_id - 1);
+ chan = chan->xdev->chan[chan_offset];
+ /* Read the status and ack the interrupts. */
+ status = dma_ctrl_read(chan, XILINX_MCDMA_CHAN_SR_OFFSET(chan->tdest));
+ if (!(status & XILINX_MCDMA_IRQ_ALL_MASK))
+ return IRQ_NONE;
+
+ dma_ctrl_write(chan, XILINX_MCDMA_CHAN_SR_OFFSET(chan->tdest),
+ status & XILINX_MCDMA_IRQ_ALL_MASK);
+
+ if (status & XILINX_MCDMA_IRQ_ERR_MASK) {
+ dev_err(chan->dev, "Channel %p has errors %x cdr %x tdr %x\n",
+ chan,
+ dma_ctrl_read(chan, XILINX_MCDMA_CH_ERR_OFFSET),
+ dma_ctrl_read(chan, XILINX_MCDMA_CHAN_CDESC_OFFSET
+ (chan->tdest)),
+ dma_ctrl_read(chan, XILINX_MCDMA_CHAN_TDESC_OFFSET
+ (chan->tdest)));
+ chan->err = true;
+ }
+
+ if (status & XILINX_MCDMA_IRQ_DELAY_MASK) {
+ /*
+ * Device takes too long to do the transfer when user requires
+ * responsiveness.
+ */
+ dev_dbg(chan->dev, "Inter-packet latency too long\n");
+ }
+
+ if (status & XILINX_MCDMA_IRQ_IOC_MASK) {
+ spin_lock(&chan->lock);
+ xilinx_dma_complete_descriptor(chan);
+ chan->idle = true;
+ chan->start_transfer(chan);
+ spin_unlock(&chan->lock);
+ }
+
+ tasklet_schedule(&chan->tasklet);
+ return IRQ_HANDLED;
+}
+
+/**
* xilinx_dma_irq_handler - DMA Interrupt handler
* @irq: IRQ number
* @data: Pointer to the Xilinx DMA channel structure
@@ -1972,6 +2291,104 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic(
}

/**
+ * xilinx_mcdma_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_mcdma_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_dma_chan *chan = to_xilinx_chan(dchan);
+ struct xilinx_dma_tx_descriptor *desc;
+ struct xilinx_aximcdma_tx_segment *segment = NULL;
+ u32 *app_w = (u32 *)context;
+ struct scatterlist *sg;
+ size_t copy;
+ size_t sg_used;
+ unsigned int i;
+
+ if (!is_slave_direction(direction))
+ return NULL;
+
+ /* Allocate a transaction descriptor. */
+ desc = xilinx_dma_alloc_tx_descriptor(chan);
+ if (!desc)
+ return NULL;
+
+ dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
+ desc->async_tx.tx_submit = xilinx_dma_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_aximcdma_desc_hw *hw;
+
+ /* Get a free segment */
+ segment = xilinx_aximcdma_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,
+ chan->xdev->max_buffer_len);
+ hw = &segment->hw;
+
+ /* Fill in the descriptor */
+ xilinx_aximcdma_buf(chan, hw, sg_dma_address(sg),
+ sg_used);
+ hw->control = copy;
+
+ if (chan->direction == DMA_MEM_TO_DEV && app_w) {
+ memcpy(hw->app, app_w, sizeof(u32) *
+ XILINX_DMA_NUM_APP_WORDS);
+ }
+
+ 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_aximcdma_tx_segment, node);
+ desc->async_tx.phys = segment->phys;
+
+ /* For the last DMA_MEM_TO_DEV transfer, set EOP */
+ if (chan->direction == DMA_MEM_TO_DEV) {
+ segment->hw.control |= XILINX_MCDMA_BD_SOP;
+ segment = list_last_entry(&desc->segments,
+ struct xilinx_aximcdma_tx_segment,
+ node);
+ segment->hw.control |= XILINX_MCDMA_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
* @dchan: Driver specific DMA Channel pointer
*
@@ -2363,6 +2780,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
of_device_is_compatible(node, "xlnx,axi-cdma-channel")) {
chan->direction = DMA_MEM_TO_DEV;
chan->id = chan_id;
+ chan->tdest = chan_id;

chan->ctrl_offset = XILINX_DMA_MM2S_CTRL_OFFSET;
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
@@ -2379,6 +2797,8 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
"xlnx,axi-dma-s2mm-channel")) {
chan->direction = DMA_DEV_TO_MEM;
chan->id = chan_id;
+ xdev->s2mm_index = xdev->nr_channels;
+ chan->tdest = chan_id - xdev->nr_channels;
chan->has_vflip = of_property_read_bool(node,
"xlnx,enable-vert-flip");
if (chan->has_vflip) {
@@ -2387,7 +2807,11 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
XILINX_VDMA_ENABLE_VERTICAL_FLIP;
}

- chan->ctrl_offset = XILINX_DMA_S2MM_CTRL_OFFSET;
+ if (xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA)
+ chan->ctrl_offset = XILINX_MCDMA_S2MM_CTRL_OFFSET;
+ else
+ chan->ctrl_offset = XILINX_DMA_S2MM_CTRL_OFFSET;
+
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
chan->desc_offset = XILINX_VDMA_S2MM_DESC_OFFSET;
chan->config.park = 1;
@@ -2402,7 +2826,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
}

/* Request the interrupt */
- chan->irq = irq_of_parse_and_map(node, 0);
+ chan->irq = irq_of_parse_and_map(node, chan->tdest);
err = request_irq(chan->irq, xdev->dma_config->irq_handler,
IRQF_SHARED, "xilinx-dma-controller", chan);
if (err) {
@@ -2413,6 +2837,9 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
chan->start_transfer = xilinx_dma_start_transfer;
chan->stop_transfer = xilinx_dma_stop_transfer;
+ } else if (xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA) {
+ chan->start_transfer = xilinx_mcdma_start_transfer;
+ chan->stop_transfer = xilinx_dma_stop_transfer;
} else if (xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
chan->start_transfer = xilinx_cdma_start_transfer;
chan->stop_transfer = xilinx_cdma_stop_transfer;
@@ -2466,7 +2893,11 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
struct device_node *node)
{
- int i, nr_channels = 1;
+ int ret, i, nr_channels = 1;
+
+ ret = of_property_read_u32(node, "dma-channels", &nr_channels);
+ if (xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA && ret < 0)
+ dev_warn(xdev->dev, "missing dma-channels property\n");

for (i = 0; i < nr_channels; i++)
xilinx_dma_chan_probe(xdev, node, xdev->chan_id++);
@@ -2501,6 +2932,11 @@ static const struct xilinx_dma_config axidma_config = {
.irq_handler = xilinx_dma_irq_handler,
};

+static const struct xilinx_dma_config aximcdma_config = {
+ .dmatype = XDMA_TYPE_AXIMCDMA,
+ .clk_init = axidma_clk_init,
+ .irq_handler = xilinx_mcdma_irq_handler,
+};
static const struct xilinx_dma_config axicdma_config = {
.dmatype = XDMA_TYPE_CDMA,
.clk_init = axicdma_clk_init,
@@ -2517,6 +2953,7 @@ static const struct of_device_id xilinx_dma_of_ids[] = {
{ .compatible = "xlnx,axi-dma-1.00.a", .data = &axidma_config },
{ .compatible = "xlnx,axi-cdma-1.00.a", .data = &axicdma_config },
{ .compatible = "xlnx,axi-vdma-1.00.a", .data = &axivdma_config },
+ { .compatible = "xlnx,axi-mcdma-1.00.a", .data = &aximcdma_config },
{}
};
MODULE_DEVICE_TABLE(of, xilinx_dma_of_ids);
@@ -2567,7 +3004,8 @@ static int xilinx_dma_probe(struct platform_device *pdev)
/* Retrieve the DMA engine properties from the device tree */
xdev->max_buffer_len = GENMASK(XILINX_DMA_MAX_TRANS_LEN_MAX - 1, 0);

- if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
+ if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA ||
+ xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA) {
if (!of_property_read_u32(node, "xlnx,sg-length-width",
&len_width)) {
if (len_width < XILINX_DMA_MAX_TRANS_LEN_MIN ||
@@ -2640,7 +3078,9 @@ static int xilinx_dma_probe(struct platform_device *pdev)
xdev->common.device_prep_dma_memcpy = xilinx_cdma_prep_memcpy;
/* Residue calculation is supported by only AXI DMA and CDMA */
xdev->common.residue_granularity =
- DMA_RESIDUE_GRANULARITY_SEGMENT;
+ DMA_RESIDUE_GRANULARITY_SEGMENT;
+ } else if (xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA) {
+ xdev->common.device_prep_slave_sg = xilinx_mcdma_prep_slave_sg;
} else {
xdev->common.device_prep_interleaved_dma =
xilinx_vdma_dma_prep_interleaved;
@@ -2676,6 +3116,8 @@ static int xilinx_dma_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "Xilinx AXI DMA Engine Driver Probed!!\n");
else if (xdev->dma_config->dmatype == XDMA_TYPE_CDMA)
dev_info(&pdev->dev, "Xilinx AXI CDMA Engine Driver Probed!!\n");
+ else if (xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA)
+ dev_info(&pdev->dev, "Xilinx AXI MCDMA Engine Driver Probed!!\n");
else
dev_info(&pdev->dev, "Xilinx AXI VDMA Engine Driver Probed!!\n");

--
2.7.4