Re: [RESEND][PATCH v2] dmaengine: bcm2835: Add slave dma support

From: Vinod Koul
Date: Fri Dec 18 2015 - 01:02:17 EST


On Thu, Dec 17, 2015 at 07:11:48PM +0100, Martin Sperl wrote:

> +
> + /* Setup addresses */
> + if (d->dir == DMA_DEV_TO_MEM) {
> + control_block->info = BCM2835_DMA_D_INC |
> + BCM2835_DMA_D_WIDTH |
> + BCM2835_DMA_S_DREQ;
> + control_block->src = dev_addr;
> + control_block->dst = addr + (dma_addr_t)j;
> + } else {
> + control_block->info = BCM2835_DMA_S_INC |
> + BCM2835_DMA_S_WIDTH |
> + BCM2835_DMA_D_DREQ;
> + control_block->src = addr + (dma_addr_t)j;
> + control_block->dst = dev_addr;
> + }
> +
> + /* Common part */
> + control_block->info |=
> + BCM2835_DMA_WAITS(BCM2835_DMA_WAIT_CYCLES);
> + control_block->info |= BCM2835_DMA_WAIT_RESP;
> +
> + /* Enable */
> + if (i == sg_len - 1 && len - j <= max_size)
> + control_block->info |= BCM2835_DMA_INT_EN;
> +
> + /* Setup synchronization */
> + if (sync_type)
> + control_block->info |= sync_type;
> +
> + /* Setup DREQ channel */
> + if (c->dreq)
> + control_block->info |=
> + BCM2835_DMA_PER_MAP(c->dreq);
> +
> + /* Length of a frame */
> + control_block->length = min(len - j, max_size);
> + d->size += control_block->length;
> +
> + if (i < sg_len - 1 || len - j > max_size) {
> + /* Next block is the next frame. */
> + control_block->next =
> + d->control_block_base_phys +
> + sizeof(struct bcm2835_dma_cb) *
> + (i + split_cnt + 1);
> + } else {
> + /* Next block is empty. */
> + control_block->next = 0;
> + }
> +
> + if (len - j > max_size)
> + split_cnt++;

Most of this part is common with the cyclic and seems copy paste. Can we
use common routine to do common work please

--
~Vinod
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