dmaengine: vdma: Add Support for Xilinx AXI Central Direct Memory Access Engine
authorKedareswara rao Appana <appana.durga.rao@xilinx.com>
Thu, 7 Apr 2016 05:29:45 +0000 (10:59 +0530)
committerVinod Koul <vinod.koul@intel.com>
Thu, 12 May 2016 06:28:58 +0000 (11:58 +0530)
This patch adds support for the AXI Central Direct Memory Access
(AXI CDMA) core to the existing vdma driver, AXI CDMA 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@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
drivers/dma/xilinx/xilinx_vdma.c
include/linux/dma/xilinx_dma.h

index 983e4bc88cd8107155e72455692478fd0b383343..fb481135f27a331472731639cfd492fbe9b3624f 100644 (file)
  * and AXI4-Stream target peripherals. It supports one receive and one
  * transmit channel, both of them optional at synthesis time.
  *
+ * 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
 #define XILINX_DMA_COALESCE_MAX                255
 #define XILINX_DMA_NUM_APP_WORDS       5
 
+/* AXI CDMA Specific Registers/Offsets */
+#define XILINX_CDMA_REG_SRCADDR                0x18
+#define XILINX_CDMA_REG_DSTADDR                0x20
+
+/* AXI CDMA Specific Masks */
+#define XILINX_CDMA_CR_SGMODE          BIT(3)
+
 /**
  * struct xilinx_vdma_desc_hw - Hardware Descriptor
  * @next_desc: Next Descriptor Pointer @0x00
@@ -203,6 +214,28 @@ struct xilinx_axidma_desc_hw {
        u32 app[XILINX_DMA_NUM_APP_WORDS];
 } __aligned(64);
 
+/**
+ * struct xilinx_cdma_desc_hw - Hardware Descriptor
+ * @next_desc: Next Descriptor Pointer @0x00
+ * @pad1: Reserved @0x04
+ * @src_addr: Source address @0x08
+ * @pad2: Reserved @0x0C
+ * @dest_addr: Destination address @0x10
+ * @pad3: Reserved @0x14
+ * @control: Control field @0x18
+ * @status: Status field @0x1C
+ */
+struct xilinx_cdma_desc_hw {
+       u32 next_desc;
+       u32 pad1;
+       u32 src_addr;
+       u32 pad2;
+       u32 dest_addr;
+       u32 pad3;
+       u32 control;
+       u32 status;
+} __aligned(64);
+
 /**
  * struct xilinx_vdma_tx_segment - Descriptor segment
  * @hw: Hardware descriptor
@@ -227,6 +260,18 @@ struct xilinx_axidma_tx_segment {
        dma_addr_t phys;
 } __aligned(64);
 
+/**
+ * struct xilinx_cdma_tx_segment - Descriptor segment
+ * @hw: Hardware descriptor
+ * @node: Node in the descriptor segments list
+ * @phys: Physical address of segment
+ */
+struct xilinx_cdma_tx_segment {
+       struct xilinx_cdma_desc_hw hw;
+       struct list_head node;
+       dma_addr_t phys;
+} __aligned(64);
+
 /**
  * struct xilinx_dma_tx_descriptor - Per Transaction structure
  * @async_tx: Async transaction descriptor
@@ -414,6 +459,28 @@ xilinx_vdma_alloc_tx_segment(struct xilinx_dma_chan *chan)
        return segment;
 }
 
+/**
+ * xilinx_cdma_alloc_tx_segment - Allocate transaction segment
+ * @chan: Driver specific DMA channel
+ *
+ * Return: The allocated segment on success and NULL on failure.
+ */
+static struct xilinx_cdma_tx_segment *
+xilinx_cdma_alloc_tx_segment(struct xilinx_dma_chan *chan)
+{
+       struct xilinx_cdma_tx_segment *segment;
+       dma_addr_t phys;
+
+       segment = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &phys);
+       if (!segment)
+               return NULL;
+
+       memset(segment, 0, sizeof(*segment));
+       segment->phys = phys;
+
+       return segment;
+}
+
 /**
  * xilinx_axidma_alloc_tx_segment - Allocate transaction segment
  * @chan: Driver specific DMA channel
@@ -447,6 +514,17 @@ static void xilinx_dma_free_tx_segment(struct xilinx_dma_chan *chan,
        dma_pool_free(chan->desc_pool, segment, segment->phys);
 }
 
+/**
+ * xilinx_cdma_free_tx_segment - Free transaction segment
+ * @chan: Driver specific DMA channel
+ * @segment: DMA transaction segment
+ */
+static void xilinx_cdma_free_tx_segment(struct xilinx_dma_chan *chan,
+                               struct xilinx_cdma_tx_segment *segment)
+{
+       dma_pool_free(chan->desc_pool, segment, segment->phys);
+}
+
 /**
  * xilinx_vdma_free_tx_segment - Free transaction segment
  * @chan: Driver specific DMA channel
@@ -488,6 +566,7 @@ xilinx_dma_free_tx_descriptor(struct xilinx_dma_chan *chan,
                               struct xilinx_dma_tx_descriptor *desc)
 {
        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;
 
        if (!desc)
@@ -498,6 +577,12 @@ xilinx_dma_free_tx_descriptor(struct xilinx_dma_chan *chan,
                        list_del(&segment->node);
                        xilinx_vdma_free_tx_segment(chan, segment);
                }
+       } else if (chan->xdev->dmatype == XDMA_TYPE_CDMA) {
+               list_for_each_entry_safe(cdma_segment, cdma_next,
+                                        &desc->segments, node) {
+                       list_del(&cdma_segment->node);
+                       xilinx_cdma_free_tx_segment(chan, cdma_segment);
+               }
        } else {
                list_for_each_entry_safe(axidma_segment, axidma_next,
                                         &desc->segments, node) {
@@ -631,6 +716,12 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
                                   sizeof(struct xilinx_axidma_tx_segment),
                                   __alignof__(struct xilinx_axidma_tx_segment),
                                   0);
+       } else if (chan->xdev->dmatype == XDMA_TYPE_CDMA) {
+               chan->desc_pool = dma_pool_create("xilinx_cdma_desc_pool",
+                                  chan->dev,
+                                  sizeof(struct xilinx_cdma_tx_segment),
+                                  __alignof__(struct xilinx_cdma_tx_segment),
+                                  0);
        } else {
                chan->desc_pool = dma_pool_create("xilinx_vdma_desc_pool",
                                     chan->dev,
@@ -667,6 +758,10 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
                              XILINX_DMA_DMAXR_ALL_IRQ_MASK);
        }
 
+       if ((chan->xdev->dmatype == XDMA_TYPE_CDMA) && chan->has_sg)
+               dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
+                            XILINX_CDMA_CR_SGMODE);
+
        return 0;
 }
 
@@ -919,6 +1014,66 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
        }
 }
 
+/**
+ * xilinx_cdma_start_transfer - Starts cdma transfer
+ * @chan: Driver specific channel struct pointer
+ */
+static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
+{
+       struct xilinx_dma_tx_descriptor *head_desc, *tail_desc;
+       struct xilinx_cdma_tx_segment *tail_segment;
+       u32 ctrl_reg = dma_read(chan, XILINX_DMA_REG_DMACR);
+
+       if (chan->err)
+               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_cdma_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;
+               dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, ctrl_reg);
+       }
+
+       if (chan->has_sg) {
+               dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
+                          head_desc->async_tx.phys);
+
+               /* Update tail ptr register which will start the transfer */
+               dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
+                              tail_segment->phys);
+       } else {
+               /* In simple mode */
+               struct xilinx_cdma_tx_segment *segment;
+               struct xilinx_cdma_desc_hw *hw;
+
+               segment = list_first_entry(&head_desc->segments,
+                                          struct xilinx_cdma_tx_segment,
+                                          node);
+
+               hw = &segment->hw;
+
+               dma_ctrl_write(chan, XILINX_CDMA_REG_SRCADDR, hw->src_addr);
+               dma_ctrl_write(chan, XILINX_CDMA_REG_DSTADDR, hw->dest_addr);
+
+               /* Start the transfer */
+               dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
+                               hw->control & XILINX_DMA_MAX_TRANS_LEN);
+       }
+
+       list_splice_tail_init(&chan->pending_list, &chan->active_list);
+       chan->desc_pendingcount = 0;
+}
+
 /**
  * xilinx_dma_start_transfer - Starts DMA transfer
  * @chan: Driver specific channel struct pointer
@@ -1165,6 +1320,7 @@ static void append_desc_queue(struct xilinx_dma_chan *chan,
        struct xilinx_vdma_tx_segment *tail_segment;
        struct xilinx_dma_tx_descriptor *tail_desc;
        struct xilinx_axidma_tx_segment *axidma_tail_segment;
+       struct xilinx_cdma_tx_segment *cdma_tail_segment;
 
        if (list_empty(&chan->pending_list))
                goto append;
@@ -1180,6 +1336,11 @@ static void append_desc_queue(struct xilinx_dma_chan *chan,
                                               struct xilinx_vdma_tx_segment,
                                               node);
                tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
+       } else if (chan->xdev->dmatype == XDMA_TYPE_CDMA) {
+               cdma_tail_segment = list_last_entry(&tail_desc->segments,
+                                               struct xilinx_cdma_tx_segment,
+                                               node);
+               cdma_tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
        } else {
                axidma_tail_segment = list_last_entry(&tail_desc->segments,
                                               struct xilinx_axidma_tx_segment,
@@ -1322,6 +1483,68 @@ error:
        return NULL;
 }
 
+/**
+ * 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_dma_chan *chan = to_xilinx_chan(dchan);
+       struct xilinx_dma_tx_descriptor *desc;
+       struct xilinx_cdma_tx_segment *segment, *prev;
+       struct xilinx_cdma_desc_hw *hw;
+
+       if (!len || len > XILINX_DMA_MAX_TRANS_LEN)
+               return NULL;
+
+       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;
+
+       /* Allocate the link descriptor from DMA pool */
+       segment = xilinx_cdma_alloc_tx_segment(chan);
+       if (!segment)
+               goto error;
+
+       hw = &segment->hw;
+       hw->control = len;
+       hw->src_addr = dma_src;
+       hw->dest_addr = dma_dst;
+
+       /* Fill the previous next descriptor with current */
+       prev = list_last_entry(&desc->segments,
+                              struct xilinx_cdma_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_cdma_tx_segment, node);
+       desc->async_tx.phys = segment->phys;
+       prev->hw.next_desc = segment->phys;
+
+       return &desc->async_tx;
+
+error:
+       xilinx_dma_free_tx_descriptor(chan, desc);
+       return NULL;
+}
+
 /**
  * xilinx_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
  * @dchan: DMA channel
@@ -1623,6 +1846,8 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
 
        if (xdev->dmatype == XDMA_TYPE_AXIDMA)
                chan->start_transfer = xilinx_dma_start_transfer;
+       else if (xdev->dmatype == XDMA_TYPE_CDMA)
+               chan->start_transfer = xilinx_cdma_start_transfer;
        else
                chan->start_transfer = xilinx_vdma_start_transfer;
 
@@ -1671,6 +1896,8 @@ static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
 static const struct of_device_id xilinx_dma_of_ids[] = {
        { .compatible = "xlnx,axi-dma-1.00.a",
          .data = (void *)XDMA_TYPE_AXIDMA },
+       { .compatible = "xlnx,axi-cdma-1.00.a",
+         .data = (void *)XDMA_TYPE_CDMA },
        { .compatible = "xlnx,axi-vdma-1.00.a",
          .data = (void *)XDMA_TYPE_VDMA },
        {}
@@ -1741,8 +1968,10 @@ static int xilinx_dma_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->dmatype == XDMA_TYPE_CDMA)) {
+               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_dma_alloc_chan_resources;
@@ -1756,6 +1985,9 @@ static int xilinx_dma_probe(struct platform_device *pdev)
                /* Residue calculation is supported by only AXI DMA */
                xdev->common.residue_granularity =
                                          DMA_RESIDUE_GRANULARITY_SEGMENT;
+       } else if (xdev->dmatype == XDMA_TYPE_CDMA) {
+               dma_cap_set(DMA_MEMCPY, xdev->common.cap_mask);
+               xdev->common.device_prep_dma_memcpy = xilinx_cdma_prep_memcpy;
        } else {
                xdev->common.device_prep_interleaved_dma =
                                xilinx_vdma_dma_prep_interleaved;
index 5db17ff8e2546d1b127ca65fadb9d51a782c709f..3ae3000525539bfcbd57e55de0b60390970232d0 100644 (file)
@@ -45,11 +45,13 @@ struct xilinx_vdma_config {
  * enum xdma_ip_type: DMA IP type.
  *
  * XDMA_TYPE_AXIDMA: Axi dma ip.
+ * XDMA_TYPE_CDMA: Axi cdma ip.
  * XDMA_TYPE_VDMA: Axi vdma ip.
  *
  */
 enum xdma_ip_type {
        XDMA_TYPE_AXIDMA = 0,
+       XDMA_TYPE_CDMA,
        XDMA_TYPE_VDMA,
 };
 
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