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bcm2835-dma: Add NO_WAIT_RESP flag

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Use bit 27 of the dreq value (the second cell of the DT DMA descriptor)
to request that the WAIT_RESP bit is not set.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
This commit is contained in:
Phil Elwell
2020-07-01 20:28:27 +01:00
committed by Dom Cobley
parent e56f7a5513
commit dbfdd7da27
1 changed files with 8 additions and 3 deletions
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11
drivers/dma/bcm2835-dma.c
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@@ -165,6 +165,11 @@ struct bcm2835_desc {
#define BCM2835_DMA_WAIT(x) ((x & 31) << 21) /* add DMA-wait cycles */ #define BCM2835_DMA_WAIT(x) ((x & 31) << 21) /* add DMA-wait cycles */
#define BCM2835_DMA_NO_WIDE_BURSTS BIT(26) /* no 2 beat write bursts */ #define BCM2835_DMA_NO_WIDE_BURSTS BIT(26) /* no 2 beat write bursts */
/* A fake bit to request that the driver doesn't set the WAIT_RESP bit. */
#define BCM2835_DMA_NO_WAIT_RESP BIT(27)
#define WAIT_RESP(x) ((x & BCM2835_DMA_NO_WAIT_RESP) ? \
0 : BCM2835_DMA_WAIT_RESP)
/* debug register bits */ /* debug register bits */
#define BCM2835_DMA_DEBUG_LAST_NOT_SET_ERR BIT(0) #define BCM2835_DMA_DEBUG_LAST_NOT_SET_ERR BIT(0)
#define BCM2835_DMA_DEBUG_FIFO_ERR BIT(1) #define BCM2835_DMA_DEBUG_FIFO_ERR BIT(1)
@@ -843,7 +848,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_memcpy(
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct bcm2835_desc *d; struct bcm2835_desc *d;
u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC; u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC;
u32 extra = BCM2835_DMA_INT_EN | BCM2835_DMA_WAIT_RESP; u32 extra = BCM2835_DMA_INT_EN | WAIT_RESP(c->dreq);
size_t max_len = bcm2835_dma_max_frame_length(c); size_t max_len = bcm2835_dma_max_frame_length(c);
size_t frames; size_t frames;
@@ -873,7 +878,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct bcm2835_desc *d; struct bcm2835_desc *d;
dma_addr_t src = 0, dst = 0; dma_addr_t src = 0, dst = 0;
u32 info = BCM2835_DMA_WAIT_RESP; u32 info = WAIT_RESP(c->dreq);
u32 extra = BCM2835_DMA_INT_EN; u32 extra = BCM2835_DMA_INT_EN;
size_t frames; size_t frames;
@@ -935,7 +940,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct bcm2835_desc *d; struct bcm2835_desc *d;
dma_addr_t src, dst; dma_addr_t src, dst;
u32 info = BCM2835_DMA_WAIT_RESP; u32 info = WAIT_RESP(c->dreq);
u32 extra = 0; u32 extra = 0;
size_t max_len = bcm2835_dma_max_frame_length(c); size_t max_len = bcm2835_dma_max_frame_length(c);
size_t frames; size_t frames;