On Fri, Mar 15, 2013 at 11:36:41AM +0800, Shawn Guo wrote:
> With generic DMA device tree binding and helper function
> dma_request_slave_channel() in place, dmaengine_pcm should support
> that in requesting DMA channel for users that support generic DMA
> device tree binding.
>
> Add a new API snd_dmaengine_generic_pcm_open() as the variant of
> snd_dmaengine_pcm_open(). It takes DMA client struct device pointer
> and slave channel name as arguments and calls generic DMA helper
> dma_request_slave_channel() to request DMA channel from dmaengine.
NAK
This is why we have dma_request_slave_channel_compat() API. You dont need to
write two open handlers here, just pass all the arguments and if DT is set it
will allocate a channel using dma_request_slave_channel() otherwise will do
dma_request_channel which is what you need.
>
> Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
> Cc: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> Cc: alsa-devel@xxxxxxxxxxxxxxxx
> Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> include/sound/dmaengine_pcm.h | 2 ++
> sound/soc/soc-dmaengine-pcm.c | 39 +++++++++++++++++++++++++++++++++++++++
> 2 files changed, 41 insertions(+)
>
> diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
> index b877334..452df15 100644
> --- a/include/sound/dmaengine_pcm.h
> +++ b/include/sound/dmaengine_pcm.h
> @@ -43,6 +43,8 @@ snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream
>
> int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
> dma_filter_fn filter_fn, void *filter_data);
> +int snd_dmaengine_generic_pcm_open(struct snd_pcm_substream *substream,
> + struct device *dev, const char *name);
> int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
>
> struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);
> diff --git a/sound/soc/soc-dmaengine-pcm.c b/sound/soc/soc-dmaengine-pcm.c
> index 111b7d92..970eb2b 100644
> --- a/sound/soc/soc-dmaengine-pcm.c
> +++ b/sound/soc/soc-dmaengine-pcm.c
> @@ -304,6 +304,45 @@ int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
> EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
>
> /**
> + * snd_dmaengine_generic_pcm_open - Open a dmaengine based PCM substream
> + * @substream: PCM substream
> + * @dev: pointer to DMA client device structure
> + * @name: DMA slave channel name
> + *
> + * Returns 0 on success, a negative error code otherwise.
> + *
> + * This function is a variant of snd_dmaengine_pcm_open(). It takes different
> + * parameters and calls generic DMA helper dma_request_slave_channel() to
> + * request a DMA channel from dmaengine.
> + */
> +int snd_dmaengine_generic_pcm_open(struct snd_pcm_substream *substream,
> + struct device *dev, const char *name)
> +{
> + struct dmaengine_pcm_runtime_data *prtd;
> + int ret;
> +
> + ret = snd_pcm_hw_constraint_integer(substream->runtime,
> + SNDRV_PCM_HW_PARAM_PERIODS);
> + if (ret < 0)
> + return ret;
> +
> + prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
> + if (!prtd)
> + return -ENOMEM;
> +
> + prtd->dma_chan = dma_request_slave_channel(dev, name);
> + if (!prtd->dma_chan) {
> + kfree(prtd);
> + return -ENXIO;
> + }
> +
> + substream->runtime->private_data = prtd;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(snd_dmaengine_generic_pcm_open);
> +
> +/**
> * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
> * @substream: PCM substream
> */
> --
> 1.7.9.5
>
>
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