[PATCH v4 3/5] dmaengine: vdma: Add Support for Xilinx AXI Direct Memory Access Engine

Paul Thomas pthomas8589 at gmail.com
Thu May 12 11:10:48 PDT 2016


Nice Kedar!

Is this getting applied? I would really like to see this get into the mainline.

thanks,
Paul

On Thu, Apr 7, 2016 at 1:29 AM, Kedareswara rao Appana
<appana.durga.rao at xilinx.com> wrote:
> This patch adds support for the AXI Direct Memory Access (AXI DMA)
> core in the existing vdma driver, AXI DMA Core 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>
> ---
> Changes for v4:
> ---> None.
> Changes for v3:
> ---> None.
> Changes for v2:
> ---> have differenet structures for h/w desc.
> ---> Added comments to the relevant sections as suggested by Laurent Pinchart.
> ---> Fixed trival code clean up/spacing issues as suggested by Laurent Pinchart
>
>  drivers/dma/xilinx/xilinx_vdma.c | 474 +++++++++++++++++++++++++++++++++++----
>  include/linux/dma/xilinx_dma.h   |  12 +
>  2 files changed, 444 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
> index b805a11..6ecf731 100644
> --- a/drivers/dma/xilinx/xilinx_vdma.c
> +++ b/drivers/dma/xilinx/xilinx_vdma.c
> @@ -16,6 +16,11 @@
>   * video device (S2MM). Initialization, status, interrupt and management
>   * registers are accessed through an AXI4-Lite slave interface.
>   *
> + * The AXI Direct Memory Access (AXI DMA) core is a soft Xilinx IP core that
> + * provides high-bandwidth one dimensional direct memory access between memory
> + * and AXI4-Stream target peripherals. It supports one receive and one
> + * transmit channel, both of them optional at synthesis time.
> + *
>   * 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 +145,19 @@
>  /* Delay loop counter to prevent hardware failure */
>  #define XILINX_DMA_LOOP_COUNT          1000000
>
> +/* AXI DMA Specific Registers/Offsets */
> +#define XILINX_DMA_REG_SRCDSTADDR      0x18
> +#define XILINX_DMA_REG_BTT             0x28
> +
> +/* AXI DMA Specific Masks/Bit fields */
> +#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
>   * @next_desc: Next Descriptor Pointer @0x00
> @@ -162,6 +180,30 @@ struct xilinx_vdma_desc_hw {
>  } __aligned(64);
>
>  /**
> + * struct xilinx_axidma_desc_hw - Hardware Descriptor for AXI DMA
> + * @next_desc: Next Descriptor Pointer @0x00
> + * @pad1: Reserved @0x04
> + * @buf_addr: Buffer address @0x08
> + * @pad2: Reserved @0x0C
> + * @pad3: Reserved @0x10
> + * @pad4: Reserved @0x14
> + * @control: Control field @0x18
> + * @status: Status field @0x1C
> + * @app: APP Fields @0x20 - 0x30
> + */
> +struct xilinx_axidma_desc_hw {
> +       u32 next_desc;
> +       u32 pad1;
> +       u32 buf_addr;
> +       u32 pad2;
> +       u32 pad3;
> +       u32 pad4;
> +       u32 control;
> +       u32 status;
> +       u32 app[XILINX_DMA_NUM_APP_WORDS];
> +} __aligned(64);
> +
> +/**
>   * struct xilinx_vdma_tx_segment - Descriptor segment
>   * @hw: Hardware descriptor
>   * @node: Node in the descriptor segments list
> @@ -174,6 +216,18 @@ struct xilinx_vdma_tx_segment {
>  } __aligned(64);
>
>  /**
> + * struct xilinx_axidma_tx_segment - Descriptor segment
> + * @hw: Hardware descriptor
> + * @node: Node in the descriptor segments list
> + * @phys: Physical address of segment
> + */
> +struct xilinx_axidma_tx_segment {
> +       struct xilinx_axidma_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
>   * @segments: TX segments list
> @@ -210,6 +264,9 @@ struct xilinx_dma_tx_descriptor {
>   * @desc_pendingcount: Descriptor pending count
>   * @ext_addr: Indicates 64 bit addressing is supported by dma channel
>   * @desc_submitcount: Descriptor h/w submitted count
> + * @residue: Residue for AXI DMA
> + * @seg_v: Statically allocated segments base
> + * @start_transfer: Differentiate b/w DMA IP's transfer
>   */
>  struct xilinx_dma_chan {
>         struct xilinx_dma_device *xdev;
> @@ -235,6 +292,9 @@ struct xilinx_dma_chan {
>         u32 desc_pendingcount;
>         bool ext_addr;
>         u32 desc_submitcount;
> +       u32 residue;
> +       struct xilinx_axidma_tx_segment *seg_v;
> +       void (*start_transfer)(struct xilinx_dma_chan *chan);
>  };
>
>  /**
> @@ -246,6 +306,7 @@ struct xilinx_dma_chan {
>   * @has_sg: Specifies whether Scatter-Gather is present or not
>   * @flush_on_fsync: Flush on frame sync
>   * @ext_addr: Indicates 64 bit addressing is supported by dma device
> + * @dmatype: DMA ip type
>   */
>  struct xilinx_dma_device {
>         void __iomem *regs;
> @@ -255,6 +316,7 @@ struct xilinx_dma_device {
>         bool has_sg;
>         u32 flush_on_fsync;
>         bool ext_addr;
> +       enum xdma_ip_type dmatype;
>  };
>
>  /* Macros */
> @@ -354,6 +416,39 @@ xilinx_vdma_alloc_tx_segment(struct xilinx_dma_chan *chan)
>  }
>
>  /**
> + * xilinx_axidma_alloc_tx_segment - Allocate transaction segment
> + * @chan: Driver specific DMA channel
> + *
> + * Return: The allocated segment on success and NULL on failure.
> + */
> +static struct xilinx_axidma_tx_segment *
> +xilinx_axidma_alloc_tx_segment(struct xilinx_dma_chan *chan)
> +{
> +       struct xilinx_axidma_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_dma_free_tx_segment - Free transaction segment
> + * @chan: Driver specific DMA channel
> + * @segment: DMA transaction segment
> + */
> +static void xilinx_dma_free_tx_segment(struct xilinx_dma_chan *chan,
> +                               struct xilinx_axidma_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
>   * @segment: DMA transaction segment
> @@ -394,13 +489,22 @@ 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_axidma_tx_segment *axidma_segment, *axidma_next;
>
>         if (!desc)
>                 return;
>
> -       list_for_each_entry_safe(segment, next, &desc->segments, node) {
> -               list_del(&segment->node);
> -               xilinx_vdma_free_tx_segment(chan, segment);
> +       if (chan->xdev->dmatype == XDMA_TYPE_VDMA) {
> +               list_for_each_entry_safe(segment, next, &desc->segments, node) {
> +                       list_del(&segment->node);
> +                       xilinx_vdma_free_tx_segment(chan, segment);
> +               }
> +       } else {
> +               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);
> +               }
>         }
>
>         kfree(desc);
> @@ -452,6 +556,8 @@ static void xilinx_dma_free_chan_resources(struct dma_chan *dchan)
>         dev_dbg(chan->dev, "Free all channel resources.\n");
>
>         xilinx_dma_free_descriptors(chan);
> +       if (chan->xdev->dmatype == XDMA_TYPE_AXIDMA)
> +               xilinx_dma_free_tx_segment(chan, chan->seg_v);
>         dma_pool_destroy(chan->desc_pool);
>         chan->desc_pool = NULL;
>  }
> @@ -520,10 +626,20 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
>          * We need the descriptor to be aligned to 64bytes
>          * for meeting Xilinx VDMA specification requirement.
>          */
> -       chan->desc_pool = dma_pool_create("xilinx_vdma_desc_pool",
> -                               chan->dev,
> -                               sizeof(struct xilinx_vdma_tx_segment),
> -                               __alignof__(struct xilinx_vdma_tx_segment), 0);
> +       if (chan->xdev->dmatype == XDMA_TYPE_AXIDMA) {
> +               chan->desc_pool = dma_pool_create("xilinx_dma_desc_pool",
> +                                  chan->dev,
> +                                  sizeof(struct xilinx_axidma_tx_segment),
> +                                  __alignof__(struct xilinx_axidma_tx_segment),
> +                                  0);
> +       } else {
> +               chan->desc_pool = dma_pool_create("xilinx_vdma_desc_pool",
> +                                    chan->dev,
> +                                    sizeof(struct xilinx_vdma_tx_segment),
> +                                    __alignof__(struct xilinx_vdma_tx_segment),
> +                                    0);
> +       }
> +
>         if (!chan->desc_pool) {
>                 dev_err(chan->dev,
>                         "unable to allocate channel %d descriptor pool\n",
> @@ -531,7 +647,27 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
>                 return -ENOMEM;
>         }
>
> +       if (chan->xdev->dmatype == XDMA_TYPE_AXIDMA)
> +               /*
> +                * For AXI DMA case after submitting a pending_list, keep
> +                * an extra segment allocated so that the "next descriptor"
> +                * pointer on the tail descriptor always points to a
> +                * valid descriptor, even when paused after reaching taildesc.
> +                * This way, it is possible to issue additional
> +                * transfers without halting and restarting the channel.
> +                */
> +               chan->seg_v = xilinx_axidma_alloc_tx_segment(chan);
> +
>         dma_cookie_init(dchan);
> +
> +       if (chan->xdev->dmatype == XDMA_TYPE_AXIDMA) {
> +               /* For AXI DMA resetting once channel will reset the
> +                * other channel as well so enable the interrupts here.
> +                */
> +               dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
> +                             XILINX_DMA_DMAXR_ALL_IRQ_MASK);
> +       }
> +
>         return 0;
>  }
>
> @@ -547,7 +683,37 @@ static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan,
>                                         dma_cookie_t cookie,
>                                         struct dma_tx_state *txstate)
>  {
> -       return dma_cookie_status(dchan, cookie, txstate);
> +       struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
> +       struct xilinx_dma_tx_descriptor *desc;
> +       struct xilinx_axidma_tx_segment *segment;
> +       struct xilinx_axidma_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->dmatype == XDMA_TYPE_AXIDMA) {
> +               spin_lock_irqsave(&chan->lock, flags);
> +
> +               desc = list_last_entry(&chan->active_list,
> +                                      struct xilinx_dma_tx_descriptor, node);
> +               if (chan->has_sg) {
> +                       list_for_each_entry(segment, &desc->segments, node) {
> +                               hw = &segment->hw;
> +                               residue += (hw->control - hw->status) &
> +                                          XILINX_DMA_MAX_TRANS_LEN;
> +                       }
> +               }
> +               spin_unlock_irqrestore(&chan->lock, flags);
> +
> +               chan->residue = residue;
> +               dma_set_residue(txstate, chan->residue);
> +       }
> +
> +       return ret;
>  }
>
>  /**
> @@ -755,6 +921,91 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
>  }
>
>  /**
> + * xilinx_dma_start_transfer - Starts DMA transfer
> + * @chan: Driver specific channel struct pointer
> + */
> +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;
> +       u32 reg;
> +
> +       if (chan->err)
> +               return;
> +
> +       if (list_empty(&chan->pending_list))
> +               return;
> +
> +       /* If it is SG mode and hardware is busy, cannot submit */
> +       if (chan->has_sg && xilinx_dma_is_running(chan) &&
> +           !xilinx_dma_is_idle(chan)) {
> +               dev_dbg(chan->dev, "DMA controller still busy\n");
> +               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);
> +
> +       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;
> +
> +       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);
> +
> +       if (chan->desc_pendingcount <= XILINX_DMA_COALESCE_MAX) {
> +               reg &= ~XILINX_DMA_CR_COALESCE_MAX;
> +               reg |= chan->desc_pendingcount <<
> +                                 XILINX_DMA_CR_COALESCE_SHIFT;
> +               dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
> +       }
> +
> +       if (chan->has_sg)
> +               dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
> +                              head_desc->async_tx.phys);
> +
> +       xilinx_dma_start(chan);
> +
> +       if (chan->err)
> +               return;
> +
> +       /* Start the transfer */
> +       if (chan->has_sg) {
> +               dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
> +                              tail_segment->phys);
> +       } else {
> +               struct xilinx_axidma_tx_segment *segment;
> +               struct xilinx_axidma_desc_hw *hw;
> +
> +               segment = list_first_entry(&head_desc->segments,
> +                                          struct xilinx_axidma_tx_segment,
> +                                          node);
> +               hw = &segment->hw;
> +
> +               dma_ctrl_write(chan, XILINX_DMA_REG_SRCDSTADDR, hw->buf_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_issue_pending - Issue pending transactions
>   * @dchan: DMA channel
>   */
> @@ -764,7 +1015,7 @@ static void xilinx_dma_issue_pending(struct dma_chan *dchan)
>         unsigned long flags;
>
>         spin_lock_irqsave(&chan->lock, flags);
> -       xilinx_vdma_start_transfer(chan);
> +       chan->start_transfer(chan);
>         spin_unlock_irqrestore(&chan->lock, flags);
>  }
>
> @@ -896,7 +1147,7 @@ static irqreturn_t xilinx_dma_irq_handler(int irq, void *data)
>         if (status & XILINX_DMA_DMASR_FRM_CNT_IRQ) {
>                 spin_lock(&chan->lock);
>                 xilinx_dma_complete_descriptor(chan);
> -               xilinx_vdma_start_transfer(chan);
> +               chan->start_transfer(chan);
>                 spin_unlock(&chan->lock);
>         }
>
> @@ -914,6 +1165,7 @@ 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;
>
>         if (list_empty(&chan->pending_list))
>                 goto append;
> @@ -924,9 +1176,17 @@ static void append_desc_queue(struct xilinx_dma_chan *chan,
>          */
>         tail_desc = list_last_entry(&chan->pending_list,
>                                     struct xilinx_dma_tx_descriptor, node);
> -       tail_segment = list_last_entry(&tail_desc->segments,
> -                                      struct xilinx_vdma_tx_segment, node);
> -       tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
> +       if (chan->xdev->dmatype == XDMA_TYPE_VDMA) {
> +               tail_segment = list_last_entry(&tail_desc->segments,
> +                                              struct xilinx_vdma_tx_segment,
> +                                              node);
> +               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,
> +                                              node);
> +               axidma_tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
> +       }
>
>         /*
>          * Add the software descriptor and all children to the list
> @@ -936,7 +1196,7 @@ append:
>         list_add_tail(&desc->node, &chan->pending_list);
>         chan->desc_pendingcount++;
>
> -       if (chan->has_sg &&
> +       if (chan->has_sg && (chan->xdev->dmatype == XDMA_TYPE_VDMA) &&
>             unlikely(chan->desc_pendingcount > chan->num_frms)) {
>                 dev_dbg(chan->dev, "desc pendingcount is too high\n");
>                 chan->desc_pendingcount = chan->num_frms;
> @@ -1064,6 +1324,109 @@ 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_dma_chan *chan = to_xilinx_chan(dchan);
> +       struct xilinx_dma_tx_descriptor *desc;
> +       struct xilinx_axidma_tx_segment *segment = NULL, *prev = 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_axidma_desc_hw *hw;
> +
> +                       /* Get a free segment */
> +                       segment = xilinx_axidma_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 = 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_axidma_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 |= 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
>   */
> @@ -1225,22 +1588,26 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
>                 chan->id = 0;
>
>                 chan->ctrl_offset = XILINX_DMA_MM2S_CTRL_OFFSET;
> -               chan->desc_offset = XILINX_VDMA_MM2S_DESC_OFFSET;
> +               if (xdev->dmatype == XDMA_TYPE_VDMA) {
> +                       chan->desc_offset = XILINX_VDMA_MM2S_DESC_OFFSET;
>
> -               if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
> -                   xdev->flush_on_fsync == XILINX_DMA_FLUSH_MM2S)
> -                       chan->flush_on_fsync = true;
> +                       if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
> +                           xdev->flush_on_fsync == XILINX_DMA_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_DMA_S2MM_CTRL_OFFSET;
> -               chan->desc_offset = XILINX_VDMA_S2MM_DESC_OFFSET;
> +               if (xdev->dmatype == XDMA_TYPE_VDMA) {
> +                       chan->desc_offset = XILINX_VDMA_S2MM_DESC_OFFSET;
>
> -               if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
> -                   xdev->flush_on_fsync == XILINX_DMA_FLUSH_S2MM)
> -                       chan->flush_on_fsync = true;
> +                       if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
> +                           xdev->flush_on_fsync == XILINX_DMA_FLUSH_S2MM)
> +                               chan->flush_on_fsync = true;
> +               }
>         } else {
>                 dev_err(xdev->dev, "Invalid channel compatible node\n");
>                 return -EINVAL;
> @@ -1255,6 +1622,11 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
>                 return err;
>         }
>
> +       if (xdev->dmatype == XDMA_TYPE_AXIDMA)
> +               chan->start_transfer = xilinx_dma_start_transfer;
> +       else
> +               chan->start_transfer = xilinx_vdma_start_transfer;
> +
>         /* Initialize the tasklet */
>         tasklet_init(&chan->tasklet, xilinx_dma_do_tasklet,
>                         (unsigned long)chan);
> @@ -1297,6 +1669,15 @@ static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
>         return dma_get_slave_channel(&xdev->chan[chan_id]->common);
>  }
>
> +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-vdma-1.00.a",
> +         .data = (void *)XDMA_TYPE_VDMA },
> +       {}
> +};
> +MODULE_DEVICE_TABLE(of, xilinx_dma_of_ids);
> +
>  /**
>   * xilinx_dma_probe - Driver probe function
>   * @pdev: Pointer to the platform_device structure
> @@ -1318,6 +1699,7 @@ static int xilinx_dma_probe(struct platform_device *pdev)
>                 return -ENOMEM;
>
>         xdev->dev = &pdev->dev;
> +       xdev->dmatype = (enum xdma_ip_type)of_device_get_match_data(&pdev->dev);
>
>         /* Request and map I/O memory */
>         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> @@ -1328,16 +1710,21 @@ 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");
>
> -       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->dmatype == XDMA_TYPE_VDMA) {
> +               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");
> +               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,addrwidth", &addr_width);
>         if (err < 0)
> @@ -1362,11 +1749,18 @@ static int xilinx_dma_probe(struct platform_device *pdev)
>                                 xilinx_dma_alloc_chan_resources;
>         xdev->common.device_free_chan_resources =
>                                 xilinx_dma_free_chan_resources;
> -       xdev->common.device_prep_interleaved_dma =
> -                               xilinx_vdma_dma_prep_interleaved;
>         xdev->common.device_terminate_all = xilinx_dma_terminate_all;
>         xdev->common.device_tx_status = xilinx_dma_tx_status;
>         xdev->common.device_issue_pending = xilinx_dma_issue_pending;
> +       if (xdev->dmatype == XDMA_TYPE_AXIDMA) {
> +               xdev->common.device_prep_slave_sg = xilinx_dma_prep_slave_sg;
> +               /* Residue calculation is supported by only AXI DMA */
> +               xdev->common.residue_granularity =
> +                                         DMA_RESIDUE_GRANULARITY_SEGMENT;
> +       } else {
> +               xdev->common.device_prep_interleaved_dma =
> +                               xilinx_vdma_dma_prep_interleaved;
> +       }
>
>         platform_set_drvdata(pdev, xdev);
>
> @@ -1377,9 +1771,11 @@ static int xilinx_dma_probe(struct platform_device *pdev)
>                         goto error;
>         }
>
> -       for (i = 0; i < XILINX_DMA_MAX_CHANS_PER_DEVICE; i++)
> -               if (xdev->chan[i])
> -                       xdev->chan[i]->num_frms = num_frames;
> +       if (xdev->dmatype == XDMA_TYPE_VDMA) {
> +               for (i = 0; i < XILINX_DMA_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);
> @@ -1426,12 +1822,6 @@ static int xilinx_dma_remove(struct platform_device *pdev)
>         return 0;
>  }
>
> -static const struct of_device_id xilinx_dma_of_ids[] = {
> -       { .compatible = "xlnx,axi-vdma-1.00.a",},
> -       {}
> -};
> -MODULE_DEVICE_TABLE(of, xilinx_dma_of_ids);
> -
>  static struct platform_driver xilinx_vdma_driver = {
>         .driver = {
>                 .name = "xilinx-vdma",
> diff --git a/include/linux/dma/xilinx_dma.h b/include/linux/dma/xilinx_dma.h
> index 34b98f2..5db17ff 100644
> --- a/include/linux/dma/xilinx_dma.h
> +++ b/include/linux/dma/xilinx_dma.h
> @@ -41,6 +41,18 @@ struct xilinx_vdma_config {
>         int ext_fsync;
>  };
>
> +/**
> + * enum xdma_ip_type: DMA IP type.
> + *
> + * XDMA_TYPE_AXIDMA: Axi dma ip.
> + * XDMA_TYPE_VDMA: Axi vdma ip.
> + *
> + */
> +enum xdma_ip_type {
> +       XDMA_TYPE_AXIDMA = 0,
> +       XDMA_TYPE_VDMA,
> +};
> +
>  int xilinx_vdma_channel_set_config(struct dma_chan *dchan,
>                                         struct xilinx_vdma_config *cfg);
>
> --
> 2.1.2
>
>
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> linux-arm-kernel at lists.infradead.org
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