Re: [PATCH v2 3/6] dma: Add a jz4740 dmaengine driver

From: Vinod Koul
Date: Thu May 30 2013 - 13:50:53 EST


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.

--
~Vinod
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