Re: [PATCH RFC v4 2/8] ALSA: pcm: add IEC958 channel status helper for hw_params

From: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Jyri Sarha <jsarha-l0cyMroinI0@public.gmane.org>
Cc: dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org,
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Subject: Re: [PATCH RFC v4 2/8] ALSA: pcm: add IEC958 channel status helper for hw_params
Date: Sat, 19 Sep 2015 10:46:24 -0700	[thread overview]
Message-ID: <20150919174624.GK30445@sirena.org.uk> (raw)
In-Reply-To: <a7b69fb075b0ae993846cfb65abb20ecab5c9805.1442572860.git.jsarha-l0cyMroinI0@public.gmane.org>

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On Fri, Sep 18, 2015 at 02:06:39PM +0300, Jyri Sarha wrote:
> Add IEC958 channel status helper that gets the audio properties from
> snd_pcm_hw_params instead of snd_pcm_runtime. This is needed to
> produce the channel status bits already in audio stream configuration
> phase.
> 
> Signed-off-by: Jyri Sarha <jsarha-l0cyMroinI0@public.gmane.org>
> ---
>  include/sound/pcm_iec958.h |  2 ++
>  sound/core/pcm_iec958.c    | 52 +++++++++++++++++++++++++++++++---------------

This is core ALSA code, you need to CC Takashi (added him, not cutting
context).

>  2 files changed, 37 insertions(+), 17 deletions(-)
> 
> diff --git a/include/sound/pcm_iec958.h b/include/sound/pcm_iec958.h
> index 0eed397..36f023a 100644
> --- a/include/sound/pcm_iec958.h
> +++ b/include/sound/pcm_iec958.h
> @@ -6,4 +6,6 @@
>  int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
>  	size_t len);
>  
> +int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
> +					     u8 *cs, size_t len);
>  #endif
> diff --git a/sound/core/pcm_iec958.c b/sound/core/pcm_iec958.c
> index 36b2d7a..c9f8b66 100644
> --- a/sound/core/pcm_iec958.c
> +++ b/sound/core/pcm_iec958.c
> @@ -9,30 +9,18 @@
>  #include <linux/types.h>
>  #include <sound/asoundef.h>
>  #include <sound/pcm.h>
> +#include <sound/pcm_params.h>
>  #include <sound/pcm_iec958.h>
>  
> -/**
> - * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status
> - * @runtime: pcm runtime structure with ->rate filled in
> - * @cs: channel status buffer, at least four bytes
> - * @len: length of channel status buffer
> - *
> - * Create the consumer format channel status data in @cs of maximum size
> - * @len corresponding to the parameters of the PCM runtime @runtime.
> - *
> - * Drivers may wish to tweak the contents of the buffer after creation.
> - *
> - * Returns: length of buffer, or negative error code if something failed.
> - */
> -int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
> -	size_t len)
> +static int create_iec958_consumer(uint rate, uint sample_width,
> +				  u8 *cs, size_t len)
>  {
>  	unsigned int fs, ws;
>  
>  	if (len < 4)
>  		return -EINVAL;
>  
> -	switch (runtime->rate) {
> +	switch (rate) {
>  	case 32000:
>  		fs = IEC958_AES3_CON_FS_32000;
>  		break;
> @@ -59,7 +47,7 @@ int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
>  	}
>  
>  	if (len > 4) {
> -		switch (snd_pcm_format_width(runtime->format)) {
> +		switch (sample_width) {
>  		case 16:
>  			ws = IEC958_AES4_CON_WORDLEN_20_16;
>  			break;
> @@ -92,4 +80,34 @@ int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
>  
>  	return len;
>  }
> +
> +/**
> + * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status
> + * @runtime: pcm runtime structure with ->rate filled in
> + * @cs: channel status buffer, at least four bytes
> + * @len: length of channel status buffer
> + *
> + * Create the consumer format channel status data in @cs of maximum size
> + * @len corresponding to the parameters of the PCM runtime @runtime.
> + *
> + * Drivers may wish to tweak the contents of the buffer after creation.
> + *
> + * Returns: length of buffer, or negative error code if something failed.
> + */
> +int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
> +	size_t len)
> +{
> +	return create_iec958_consumer(runtime->rate,
> +				      snd_pcm_format_width(runtime->format),
> +				      cs, len);
> +}
>  EXPORT_SYMBOL(snd_pcm_create_iec958_consumer);
> +
> +
> +int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
> +					     u8 *cs, size_t len)
> +{
> +	return create_iec958_consumer(params_rate(params), params_width(params),
> +				      cs, len);
> +}
> +EXPORT_SYMBOL(snd_pcm_create_iec958_consumer_hw_params);
> -- 
> 1.9.1
> 
> 

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