Re: [PATCH] ASoC: io: Remove hw_read() operation

[Lars-Peter Clausen <lars@metafoo.de>]

On 03/04/2014 10:10 AM, Mark Brown wrote:
> From: Mark Brown <broonie@linaro.org>
>
> We now no longer have any users of hw_read() in the kernel so remove the
> code in order to prevent any new users being added. Users should be using
> regmap.
>
> Signed-off-by: Mark Brown <broonie@linaro.org>
> ---
>   include/sound/soc.h |  1 -
>   sound/soc/soc-io.c  | 13 -------------
>   2 files changed, 14 deletions(-)
>
> diff --git a/include/sound/soc.h b/include/sound/soc.h
> index 56c4c71..dc36331 100644
> --- a/include/sound/soc.h
> +++ b/include/sound/soc.h
> @@ -706,7 +706,6 @@ struct snd_soc_codec {
>   	/* codec IO */
>   	void *control_data; /* codec control (i2c/3wire) data */
>   	hw_write_t hw_write;
> -	unsigned int (*hw_read)(struct snd_soc_codec *, unsigned int);

This part is OK.

>   	unsigned int (*read)(struct snd_soc_codec *, unsigned int);
>   	int (*write)(struct snd_soc_codec *, unsigned int, unsigned int);
>   	void *reg_cache;
> diff --git a/sound/soc/soc-io.c b/sound/soc/soc-io.c
> index c3b6a0a..3c1de9c 100644
> --- a/sound/soc/soc-io.c
> +++ b/sound/soc/soc-io.c
> @@ -26,18 +26,6 @@ static int hw_write(struct snd_soc_codec *codec, unsigned int reg,
>   	return regmap_write(codec->control_data, reg, value);
>   }
>
> -static unsigned int hw_read(struct snd_soc_codec *codec, unsigned int reg)
> -{
> -	int ret;
> -	unsigned int val;
> -
> -	ret = regmap_read(codec->control_data, reg, &val);
> -	if (ret == 0)
> -		return val;
> -	else
> -		return -1;
> -}
> -
>   /**
>    * snd_soc_codec_set_cache_io: Set up standard I/O functions.
>    *
> @@ -64,7 +52,6 @@ int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
>   	int ret;
>
>   	codec->write = hw_write;
> -	codec->read = hw_read;

But this part will break snd_soc_read() and with it basically every driver 
that has any controls or DAPM widgets.

I do have a set of patches that moves IO to the component level that will 
clean this all up quite a bit. I'm just waiting for Xiubo Li 
snd_soc_codec_set_cache_io() cleanup to be merged first, since it will make 
things a bit simpler.

>
>   	switch (control) {
>   	case SND_SOC_REGMAP:
>