[alsa-devel] [PATCH v2 3/6] dma: Add a jz4740 dmaengine driver

Vinod Koul vinod.koul at intel.com
Thu May 30 19:12:26 CEST 2013

On Thu, May 30, 2013 at 06:25:02PM +0200, Lars-Peter Clausen wrote:
> This patch adds dmaengine support for the JZ4740 DMA controller. For now the
> driver will be a wrapper around the custom JZ4740 DMA API. Once all users of the
> custom JZ4740 DMA API have been converted to the dmaengine API the custom API
> will be removed and direct hardware access will be added to the dmaengine
> driver.
> +
> +#include <asm/mach-jz4740/dma.h>
Am bit worried about having header in arch. Why cant we have this drivers header
in linux/. That way same IP block cna be reused across archs.
I was hoping that you would have move it in 6th patch, but that isnt the case

> +static int jz4740_dma_alloc_chan_resources(struct dma_chan *c)
> +{
> +	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
> +
> +	chan->jz_chan = jz4740_dma_request(chan, NULL);
> +	if (!chan->jz_chan)
> +		return -EBUSY;
> +
> +	jz4740_dma_set_complete_cb(chan->jz_chan, jz4740_dma_complete_cb);
> +
> +	return 0;
Sorry, I didnt reply on this one. The API expects you to allocate a pool of
descriptors. These descriptors are to be used in .device_prep_xxx calls later.


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