Re: [PATCH v2 2/2] dmaengine: omap-dma: Support for slave devices with data port window

From: Vinod Koul
Date: Fri Nov 25 2016 - 01:03:11 EST


On Thu, Nov 17, 2016 at 02:50:17PM +0200, Peter Ujfalusi wrote:
> @@ -921,11 +931,45 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
>
> d->ccr = c->ccr | CCR_SYNC_FRAME;
> if (dir == DMA_DEV_TO_MEM) {
> - d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
> d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
> +
> + d->ccr |= CCR_DST_AMODE_POSTINC;
> + if (port_window) {
> + d->ccr |= CCR_SRC_AMODE_DBLIDX;
> + d->ei = 1;
> + /*
> + * One frame covers the port_window and by configure
> + * the source frame index to be -1 * (port_window - 1)
> + * we instruct the sDMA that after a frame is processed
> + * it should move back to the start of the window.
> + */
> + d->fi = -(port_window - 1);
> +
> + if (port_window >= 64)
> + d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
> + else if (port_window >= 32)
> + d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
> + else if (port_window >= 16)
> + d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;

this and other would look better with a switch..

--
~Vinod