git.openwrt.org Git - openwrt/staging/ldir.git/blob

   1 From 153c92ec4e0364c12f99e39106dc79e5b7167cac Mon Sep 17 00:00:00 2001
   2 From: Dom Cobley <popcornmix@gmail.com>
   3 Date: Wed, 30 Dec 2020 14:51:29 +0000
   4 Subject: [PATCH] bcm2835-dma: Add bcm2835-dma: Add DMA_WIDE_SOURCE and
   5  DMA_WIDE_DEST flags
   6
   7 Use (reserved) bits 24 and 25 of the dreq value
   8 (the second cell of the DT DMA descriptor) to request
   9 that wide source reads or wide dest writes are required
  10
  11 Signed-off-by: Dom Cobley <popcornmix@gmail.com>
  12 ---
  13  drivers/dma/bcm2835-dma.c | 19 ++++++++++++++++---
  14  1 file changed, 16 insertions(+), 3 deletions(-)
  15
  16 --- a/drivers/dma/bcm2835-dma.c
  17 +++ b/drivers/dma/bcm2835-dma.c
  18 @@ -171,6 +171,17 @@ struct bcm2835_desc {
  19  #define WAIT_RESP(x) ((x & BCM2835_DMA_NO_WAIT_RESP) ? \
  20                       0 : BCM2835_DMA_WAIT_RESP)
  21
  22 +/* A fake bit to request that the driver requires wide reads */
  23 +#define BCM2835_DMA_WIDE_SOURCE BIT(24)
  24 +#define WIDE_SOURCE(x) ((x & BCM2835_DMA_WIDE_SOURCE) ? \
  25 +                     BCM2835_DMA_S_WIDTH : 0)
  26 +
  27 +/* A fake bit to request that the driver requires wide writes */
  28 +#define BCM2835_DMA_WIDE_DEST BIT(25)
  29 +#define WIDE_DEST(x) ((x & BCM2835_DMA_WIDE_DEST) ? \
  30 +                     BCM2835_DMA_D_WIDTH : 0)
  31 +
  32 +
  33  /* debug register bits */
  34  #define BCM2835_DMA_DEBUG_LAST_NOT_SET_ERR     BIT(0)
  35  #define BCM2835_DMA_DEBUG_FIFO_ERR             BIT(1)
  36 @@ -850,7 +861,8 @@ static struct dma_async_tx_descriptor *b
  37  {
  38         struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
  39         struct bcm2835_desc *d;
  40 -       u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC;
  41 +       u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC |
  42 +                  WIDE_SOURCE(c->dreq) | WIDE_DEST(c->dreq);
  43         u32 extra = BCM2835_DMA_INT_EN | WAIT_RESP(c->dreq);
  44         size_t max_len = bcm2835_dma_max_frame_length(c);
  45         size_t frames;
  46 @@ -881,7 +893,8 @@ static struct dma_async_tx_descriptor *b
  47         struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
  48         struct bcm2835_desc *d;
  49         dma_addr_t src = 0, dst = 0;
  50 -       u32 info = WAIT_RESP(c->dreq);
  51 +       u32 info = WAIT_RESP(c->dreq) |
  52 +                  WIDE_SOURCE(c->dreq) | WIDE_DEST(c->dreq);
  53         u32 extra = BCM2835_DMA_INT_EN;
  54         size_t frames;
  55
  56 @@ -943,7 +956,7 @@ static struct dma_async_tx_descriptor *b
  57         struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
  58         struct bcm2835_desc *d;
  59         dma_addr_t src, dst;
  60 -       u32 info = WAIT_RESP(c->dreq);
  61 +       u32 info = WAIT_RESP(c->dreq) | WIDE_SOURCE(c->dreq) | WIDE_DEST(c->dreq);
  62         u32 extra = 0;
  63         size_t max_len = bcm2835_dma_max_frame_length(c);
  64         size_t frames;