On Tue, Apr 10, 2018 at 03:46:07PM +0800, Baolin Wang wrote:
> This patch adds the 'device_config' and 'device_prep_slave_sg' interfaces
> for users to configure DMA.
>
> Signed-off-by: Baolin Wang <baolin.w...@linaro.org>
> ---
> drivers/dma/sprd-dma.c | 48
> ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 48 insertions(+)
>
> diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
> index f8038de..c923fb0 100644
> --- a/drivers/dma/sprd-dma.c
> +++ b/drivers/dma/sprd-dma.c
> @@ -869,6 +869,52 @@ static int sprd_dma_config(struct dma_chan *chan, struct
> sprd_dma_desc *sdesc,
> return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
> }
>
> +static struct dma_async_tx_descriptor *
> +sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
> + unsigned int sglen, enum dma_transfer_direction dir,
> + unsigned long flags, void *context)
> +{
> + struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
> + struct sprd_dma_config *slave_cfg = &schan->slave_cfg;
> + struct sprd_dma_desc *sdesc;
> + struct scatterlist *sg;
> + int ret, i;
> +
> + /* TODO: now we only support one sg for each DMA configuration. */
> + if (!is_slave_direction(slave_cfg->config.direction) || sglen > 1)
the slave direction check seems wrong to me. .device_config shall give you
dma_slave_config. You should check here if dir passed is slave or not. If
you want to check parameters in slave_config then please use .device_config
> + return NULL;
> +
> + sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
> + if (!sdesc)
> + return NULL;
> +
> + for_each_sg(sgl, sg, sglen, i) {
> + if (slave_cfg->config.direction == DMA_MEM_TO_DEV)
> + slave_cfg->config.src_addr = sg_dma_address(sg);
Nope slave_config specifies peripheral address and not memory one passed here
--
~Vinod
