[alsa-devel] [PATCH 5/8] ASoC: dmaengine-pcm: Add a common DAI DMA data struct

[Peter Ujfalusi]

On 04/03/2013 11:06 AM, Lars-Peter Clausen wrote:
> This patch adds a common DMA data struct which can be used by DAI drivers to
> communicate their DMA configuration requirements to the DMA pcm driver.  Having
> a common data structure for this allows us to implement common functions on top
> of them, which can be used by multiple platforms.
> 
> This patch also introduces a new function to initialize certain fields of a
> dma_slave_config struct from the common DAI DMA data struct.
> 
> Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>

Tested-by: Peter Ujfalusi <peter.ujfalusi at ti.com>

> ---
>  include/sound/dmaengine_pcm.h | 24 ++++++++++++++++++++++++
>  sound/soc/soc-dmaengine-pcm.c | 37 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 61 insertions(+)
> 
> diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
> index f8a7031..9562042 100644
> --- a/include/sound/dmaengine_pcm.h
> +++ b/include/sound/dmaengine_pcm.h
> @@ -44,4 +44,28 @@ int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
>  
>  struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);
>  
> +/**
> + * struct snd_dmaengine_dai_dma_data - DAI DMA configuration data
> + * @addr: Address of the DAI data source or destination register.
> + * @addr_width: Width of the DAI data source or destination register.
> + * @maxburst: Maximum number of words(note: words, as in units of the
> + * src_addr_width member, not bytes) that can be send to or received from the
> + * DAI in one burst.
> + * @slave_id: Slave requester id for the DMA channel.
> + * @filter_data: Custom DMA channel filter data, this will usually be used when
> + * requesting the DMA channel.
> + */
> +struct snd_dmaengine_dai_dma_data {
> +	dma_addr_t addr;
> +	enum dma_slave_buswidth addr_width;
> +	u32 maxburst;
> +	unsigned int slave_id;
> +	void *filter_data;
> +};
> +
> +void snd_dmaengine_pcm_set_config_from_dai_data(
> +	const struct snd_pcm_substream *substream,
> +	const struct snd_dmaengine_dai_dma_data *dma_data,
> +	struct dma_slave_config *config);
> +
>  #endif
> diff --git a/sound/soc/soc-dmaengine-pcm.c b/sound/soc/soc-dmaengine-pcm.c
> index 7c24ded..a9a300a 100644
> --- a/sound/soc/soc-dmaengine-pcm.c
> +++ b/sound/soc/soc-dmaengine-pcm.c
> @@ -95,6 +95,43 @@ int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
>  }
>  EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
>  
> +/**
> + * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
> + *  using DAI DMA data.
> + * @substream: PCM substream
> + * @dma_data: DAI DMA data
> + * @slave_config: DMA slave configuration
> + *
> + * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
> + * slave_id fields of the DMA slave config from the same fields of the DAI DMA
> + * data struct. The src and dst fields will be initialized depending on the
> + * direction of the substream. If the substream is a playback stream the dst
> + * fields will be initialized, if it is a capture stream the src fields will be
> + * initialized. The {dst,src}_addr_width field will only be initialized if the
> + * addr_width field of the DAI DMA data struct is not equal to
> + * DMA_SLAVE_BUSWIDTH_UNDEFINED.
> + */
> +void snd_dmaengine_pcm_set_config_from_dai_data(
> +	const struct snd_pcm_substream *substream,
> +	const struct snd_dmaengine_dai_dma_data *dma_data,
> +	struct dma_slave_config *slave_config)
> +{
> +	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
> +		slave_config->dst_addr = dma_data->addr;
> +		slave_config->dst_maxburst = dma_data->maxburst;
> +		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
> +			slave_config->dst_addr_width = dma_data->addr_width;
> +	} else {
> +		slave_config->src_addr = dma_data->addr;
> +		slave_config->src_maxburst = dma_data->maxburst;
> +		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
> +			slave_config->src_addr_width = dma_data->addr_width;
> +	}
> +
> +	slave_config->slave_id = dma_data->slave_id;
> +}
> +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
> +
>  static void dmaengine_pcm_dma_complete(void *arg)
>  {
>  	struct snd_pcm_substream *substream = arg;
> 


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