Re: [PATCH 3/3] dmaengine: at_hdmac: add slave config operation

From: Vinod Koul
Date: Wed Jul 06 2011 - 22:41:26 EST


On Tue, 2011-06-28 at 13:17 +0200, Nicolas Ferre wrote:
> Only change source/destination peripheral register access width.
How about a little more explainable change log

>
> Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
> Signed-off-by: Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>
> ---
> drivers/dma/at_hdmac.c | 29 +++++++++++++++++++++++++++++
> 1 files changed, 29 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 7096adb..9cb8044 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -954,6 +954,35 @@ static int atc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
> clear_bit(ATC_IS_PAUSED, &atchan->status);
>
> spin_unlock_irqrestore(&atchan->lock, flags);
> + } else if (cmd == DMA_SLAVE_CONFIG) {
> + struct dma_slave_config *dmaengine_cfg = (void *)arg;
> + struct at_dma_slave *atslave = chan->private;
This API was created to remove chan->private, so this doesn't make sense
at all. If your intent is to have a channels internal data, then you
should consider embedding dma_chan into this structure (the way other
dma drivers do) rather than using private field.
> + enum dma_slave_buswidth sdma_width;
> + enum at_dma_slave_width atdma_width;
> +
> + /* only modify transfer size width */
> + if (!atslave)
> + return -ENXIO;
> +
> + if (dmaengine_cfg->direction == DMA_FROM_DEVICE)
> + sdma_width = dmaengine_cfg->src_addr_width;
> + else
> + sdma_width = dmaengine_cfg->dst_addr_width;
> +
> + switch (sdma_width) {
> + case DMA_SLAVE_BUSWIDTH_1_BYTE:
> + atdma_width = AT_DMA_SLAVE_WIDTH_8BIT;
> + break;
> + case DMA_SLAVE_BUSWIDTH_2_BYTES:
> + atdma_width = AT_DMA_SLAVE_WIDTH_16BIT;
> + break;
> + case DMA_SLAVE_BUSWIDTH_4_BYTES:
> + atdma_width = AT_DMA_SLAVE_WIDTH_32BIT;
> + break;
> + default:
> + return -EINVAL;
> + }
> + atslave->reg_width = atdma_width;
> } else if (cmd == DMA_TERMINATE_ALL) {
> struct at_desc *desc, *_desc;
> /*

--
~Vinod Koul
Intel Corp.

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