target/linux/brcm2708/patches-4.4/0398-dmaengine-bcm2835-add-dma_memcopy-support-to-bcm2835.patch

   1 From 764cf7045e6338c1ca850ef1fce522b31440dab9 Mon Sep 17 00:00:00 2001
   2 From: Martin Sperl <kernel@martin.sperl.org>
   3 Date: Wed, 16 Mar 2016 12:25:02 -0700
   4 Subject: [PATCH] dmaengine: bcm2835: add dma_memcopy support to bcm2835-dma
   5
   6 Also added check for an error condition in bcm2835_dma_create_cb_chain
   7 that showed up during development of this patch.
   8
   9 Tested using dmatest for all enabled channels.
  10
  11 Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
  12 Reviewed-by: Eric Anholt <eric@anholt.net>
  13 Signed-off-by: Eric Anholt <eric@anholt.net>
  14 Signed-off-by: Vinod Koul <vinod.koul@intel.com>
  15 ---
  16  drivers/dma/bcm2835-dma.c | 36 +++++++++++++++++++++++++++++++++++-
  17  1 file changed, 35 insertions(+), 1 deletion(-)
  18
  19 --- a/drivers/dma/bcm2835-dma.c
  20 +++ b/drivers/dma/bcm2835-dma.c
  21 @@ -310,6 +310,9 @@ static struct bcm2835_desc *bcm2835_dma_
  22         struct bcm2835_cb_entry *cb_entry;
  23         struct bcm2835_dma_cb *control_block;
  24
  25 +       if (!frames)
  26 +               return NULL;
  27 +
  28         /* allocate and setup the descriptor. */
  29         d = kzalloc(sizeof(*d) + frames * sizeof(struct bcm2835_cb_entry),
  30                     gfp);
  31 @@ -597,6 +600,34 @@ static void bcm2835_dma_issue_pending(st
  32         spin_unlock_irqrestore(&c->vc.lock, flags);
  33  }
  34
  35 +struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_memcpy(
  36 +       struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
  37 +       size_t len, unsigned long flags)
  38 +{
  39 +       struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
  40 +       struct bcm2835_desc *d;
  41 +       u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC;
  42 +       u32 extra = BCM2835_DMA_INT_EN | BCM2835_DMA_WAIT_RESP;
  43 +       size_t max_len = bcm2835_dma_max_frame_length(c);
  44 +       size_t frames;
  45 +
  46 +       /* if src, dst or len is not given return with an error */
  47 +       if (!src || !dst || !len)
  48 +               return NULL;
  49 +
  50 +       /* calculate number of frames */
  51 +       frames = bcm2835_dma_frames_for_length(len, max_len);
  52 +
  53 +       /* allocate the CB chain - this also fills in the pointers */
  54 +       d = bcm2835_dma_create_cb_chain(chan, DMA_MEM_TO_MEM, false,
  55 +                                       info, extra, frames,
  56 +                                       src, dst, len, 0, GFP_KERNEL);
  57 +       if (!d)
  58 +               return NULL;
  59 +
  60 +       return vchan_tx_prep(&c->vc, &d->vd, flags);
  61 +}
  62 +
  63  static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
  64         struct dma_chan *chan,
  65         struct scatterlist *sgl, unsigned int sg_len,
  66 @@ -880,17 +911,20 @@ static int bcm2835_dma_probe(struct plat
  67         dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask);
  68         dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
  69         dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
  70 +       dma_cap_set(DMA_MEMCPY, od->ddev.cap_mask);
  71         od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources;
  72         od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources;
  73         od->ddev.device_tx_status = bcm2835_dma_tx_status;
  74         od->ddev.device_issue_pending = bcm2835_dma_issue_pending;
  75         od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic;
  76         od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg;
  77 +       od->ddev.device_prep_dma_memcpy = bcm2835_dma_prep_dma_memcpy;
  78         od->ddev.device_config = bcm2835_dma_slave_config;
  79         od->ddev.device_terminate_all = bcm2835_dma_terminate_all;
  80         od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
  81         od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
  82 -       od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
  83 +       od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
  84 +                             BIT(DMA_MEM_TO_MEM);
  85         od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
  86         od->ddev.dev = &pdev->dev;
  87         INIT_LIST_HEAD(&od->ddev.channels);