[PATCH 2/2] ARM: EXYNOS: support burst mode for for dev-to-mem and dev-to-mem transmit
Vinod Koul
vinod.koul at intel.com
Mon Mar 4 00:45:56 EST 2013
On Tue, Feb 19, 2013 at 11:02:09AM +0900, Boojin Kim wrote:
> This patch adds to support burst mode for for dev-to-mem and dev-to-mem transmit
>
> Signed-off-by: Boojin Kim <boojin.kim at samsung.com>
> ---
> arch/arm/plat-samsung/dma-ops.c | 10 ++++++++--
> arch/arm/plat-samsung/include/plat/dma-ops.h | 1 +
> 2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/plat-samsung/dma-ops.c b/arch/arm/plat-samsung/dma-ops.c
> index d088afa..c25e842 100644
> --- a/arch/arm/plat-samsung/dma-ops.c
> +++ b/arch/arm/plat-samsung/dma-ops.c
> @@ -54,14 +54,20 @@ static int samsung_dmadev_config(unsigned ch,
> slave_config.direction = param->direction;
> slave_config.src_addr = param->fifo;
> slave_config.src_addr_width = param->width;
> - slave_config.src_maxburst = 1;
Hi Boojin,
what do you mean by the busrt mode here?
fwiw the meanining of above maxburst is:
@src_maxburst: the maximum number of words (note: words, as in
units of the src_addr_width member, not bytes) that can be sent
in one burst to the device. Typically something like half the
FIFO depth on I/O peripherals so you don't overflow it. This
may or may not be applicable on memory sources.
> + if (param->maxburst)
> + slave_config.src_maxburst = param->maxburst;
> + else
> + slave_config.src_maxburst = 1;
> dmaengine_slave_config(chan, &slave_config);
> } else if (param->direction == DMA_MEM_TO_DEV) {
> memset(&slave_config, 0, sizeof(struct dma_slave_config));
> slave_config.direction = param->direction;
> slave_config.dst_addr = param->fifo;
> slave_config.dst_addr_width = param->width;
> - slave_config.dst_maxburst = 1;
> + if (param->maxburst)
> + slave_config.dst_maxburst = param->maxburst;
> + else
> + slave_config.dst_maxburst = 1;
> dmaengine_slave_config(chan, &slave_config);
> } else {
> pr_warn("unsupported direction\n");
> diff --git a/arch/arm/plat-samsung/include/plat/dma-ops.h b/arch/arm/plat-samsung/include/plat/dma-ops.h
> index f5144cd..95893c7 100644
> --- a/arch/arm/plat-samsung/include/plat/dma-ops.h
> +++ b/arch/arm/plat-samsung/include/plat/dma-ops.h
> @@ -35,6 +35,7 @@ struct samsung_dma_prep {
> struct samsung_dma_config {
> enum dma_transfer_direction direction;
> enum dma_slave_buswidth width;
> + u32 maxburst;
> dma_addr_t fifo;
> };
>
> --
> 1.7.5.4
>
>
>
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