target/linux/brcm2708/patches-4.4/0400-dmaengine-bcm2835-add-dma_memcopy-support-to-bcm2835.patch

   1 From ce27d8ba202467a2b811de711ed95d17b2bb27e5 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 400/423] dmaengine: bcm2835: add dma_memcopy support to
   5  bcm2835-dma
   6
   7 Also added check for an error condition in bcm2835_dma_create_cb_chain
   8 that showed up during development of this patch.
   9
  10 Tested using dmatest for all enabled channels.
  11
  12 Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
  13 Reviewed-by: Eric Anholt <eric@anholt.net>
  14 Signed-off-by: Eric Anholt <eric@anholt.net>
  15 Signed-off-by: Vinod Koul <vinod.koul@intel.com>
  16 ---
  17  drivers/dma/bcm2835-dma.c | 36 +++++++++++++++++++++++++++++++++++-
  18  1 file changed, 35 insertions(+), 1 deletion(-)
  19
  20 --- a/drivers/dma/bcm2835-dma.c
  21 +++ b/drivers/dma/bcm2835-dma.c
  22 @@ -310,6 +310,9 @@ static struct bcm2835_desc *bcm2835_dma_
  23         struct bcm2835_cb_entry *cb_entry;
  24         struct bcm2835_dma_cb *control_block;
  25
  26 +       if (!frames)
  27 +               return NULL;
  28 +
  29         /* allocate and setup the descriptor. */
  30         d = kzalloc(sizeof(*d) + frames * sizeof(struct bcm2835_cb_entry),
  31                     gfp);
  32 @@ -597,6 +600,34 @@ static void bcm2835_dma_issue_pending(st
  33         spin_unlock_irqrestore(&c->vc.lock, flags);
  34  }
  35
  36 +struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_memcpy(
  37 +       struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
  38 +       size_t len, unsigned long flags)
  39 +{
  40 +       struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
  41 +       struct bcm2835_desc *d;
  42 +       u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC;
  43 +       u32 extra = BCM2835_DMA_INT_EN | BCM2835_DMA_WAIT_RESP;
  44 +       size_t max_len = bcm2835_dma_max_frame_length(c);
  45 +       size_t frames;
  46 +
  47 +       /* if src, dst or len is not given return with an error */
  48 +       if (!src || !dst || !len)
  49 +               return NULL;
  50 +
  51 +       /* calculate number of frames */
  52 +       frames = bcm2835_dma_frames_for_length(len, max_len);
  53 +
  54 +       /* allocate the CB chain - this also fills in the pointers */
  55 +       d = bcm2835_dma_create_cb_chain(chan, DMA_MEM_TO_MEM, false,
  56 +                                       info, extra, frames,
  57 +                                       src, dst, len, 0, GFP_KERNEL);
  58 +       if (!d)
  59 +               return NULL;
  60 +
  61 +       return vchan_tx_prep(&c->vc, &d->vd, flags);
  62 +}
  63 +
  64  static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
  65         struct dma_chan *chan,
  66         struct scatterlist *sgl, unsigned int sg_len,
  67 @@ -880,17 +911,20 @@ static int bcm2835_dma_probe(struct plat
  68         dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask);
  69         dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
  70         dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
  71 +       dma_cap_set(DMA_MEMCPY, od->ddev.cap_mask);
  72         od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources;
  73         od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources;
  74         od->ddev.device_tx_status = bcm2835_dma_tx_status;
  75         od->ddev.device_issue_pending = bcm2835_dma_issue_pending;
  76         od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic;
  77         od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg;
  78 +       od->ddev.device_prep_dma_memcpy = bcm2835_dma_prep_dma_memcpy;
  79         od->ddev.device_config = bcm2835_dma_slave_config;
  80         od->ddev.device_terminate_all = bcm2835_dma_terminate_all;
  81         od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
  82         od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
  83 -       od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
  84 +       od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
  85 +                             BIT(DMA_MEM_TO_MEM);
  86         od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
  87         od->ddev.dev = &pdev->dev;
  88         INIT_LIST_HEAD(&od->ddev.channels);