target/linux/bcm27xx/patches-5.4/950-0868-bcm2835-dma-Add-NO_WAIT_RESP-flag.patch

   1 From 8c070947d0d9ef7f890eeff329d4deb1c393ef87 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Wed, 1 Jul 2020 20:28:27 +0100
   4 Subject: [PATCH] bcm2835-dma: Add NO_WAIT_RESP flag
   5
   6 Use bit 27 of the dreq value (the second cell of the DT DMA descriptor)
   7 to request that the WAIT_RESP bit is not set.
   8
   9 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  10 ---
  11  drivers/dma/bcm2835-dma.c | 11 ++++++++---
  12  1 file changed, 8 insertions(+), 3 deletions(-)
  13
  14 --- a/drivers/dma/bcm2835-dma.c
  15 +++ b/drivers/dma/bcm2835-dma.c
  16 @@ -167,6 +167,11 @@ struct bcm2835_desc {
  17  #define BCM2835_DMA_WAIT(x)    ((x & 31) << 21) /* add DMA-wait cycles */
  18  #define BCM2835_DMA_NO_WIDE_BURSTS BIT(26) /* no 2 beat write bursts */
  19
  20 +/* A fake bit to request that the driver doesn't set the WAIT_RESP bit. */
  21 +#define BCM2835_DMA_NO_WAIT_RESP BIT(27)
  22 +#define WAIT_RESP(x) ((x & BCM2835_DMA_NO_WAIT_RESP) ? \
  23 +                     0 : BCM2835_DMA_WAIT_RESP)
  24 +
  25  /* debug register bits */
  26  #define BCM2835_DMA_DEBUG_LAST_NOT_SET_ERR     BIT(0)
  27  #define BCM2835_DMA_DEBUG_FIFO_ERR             BIT(1)
  28 @@ -845,7 +850,7 @@ static struct dma_async_tx_descriptor *b
  29         struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
  30         struct bcm2835_desc *d;
  31         u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC;
  32 -       u32 extra = BCM2835_DMA_INT_EN | BCM2835_DMA_WAIT_RESP;
  33 +       u32 extra = BCM2835_DMA_INT_EN | WAIT_RESP(c->dreq);
  34         size_t max_len = bcm2835_dma_max_frame_length(c);
  35         size_t frames;
  36
  37 @@ -875,7 +880,7 @@ static struct dma_async_tx_descriptor *b
  38         struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
  39         struct bcm2835_desc *d;
  40         dma_addr_t src = 0, dst = 0;
  41 -       u32 info = BCM2835_DMA_WAIT_RESP;
  42 +       u32 info = WAIT_RESP(c->dreq);
  43         u32 extra = BCM2835_DMA_INT_EN;
  44         size_t frames;
  45
  46 @@ -937,7 +942,7 @@ 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, dst;
  50 -       u32 info = BCM2835_DMA_WAIT_RESP;
  51 +       u32 info = WAIT_RESP(c->dreq);
  52         u32 extra = 0;
  53         size_t max_len = bcm2835_dma_max_frame_length(c);
  54         size_t frames;