On 7/18/08, Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Some codecs have unusual features in their register maps such as very
> large registers representing arrays of coefficients. Support these
> codecs in the register cache sysfs file by allowing them to provide a
> function register_display() overriding the default output for register
> contents.
My address space is sparse like Grant's. How about display_register()
returning -1 to skip the register address. The part printing the
address would need to be suppressed too.
count += sprintf(buf + count, "%2x: ", i);
Alternatively you could just make the entire codec_reg_show() overridable.
Might want to add another parameter for cached/uncached. Then we could
make a debug option to add the non-cached display.
This loop needs to be protected to not write over the sysfs limit of
PAGE_SIZE in the result. I think you will corrupt memory if PAGE_SIZE
is exceeded.
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
> include/sound/soc.h | 1 +
> sound/soc/soc-core.c | 14 ++++++++++----
> 2 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/include/sound/soc.h b/include/sound/soc.h
> index 1890d87..8b1a3e7 100644
> --- a/include/sound/soc.h
> +++ b/include/sound/soc.h
> @@ -410,6 +410,7 @@ struct snd_soc_codec {
> void *control_data; /* codec control (i2c/3wire) data */
> unsigned int (*read)(struct snd_soc_codec *, unsigned int);
> int (*write)(struct snd_soc_codec *, unsigned int, unsigned int);
> + int (*display_register)(struct snd_soc_codec *, char *, unsigned int);
> hw_write_t hw_write;
> hw_read_t hw_read;
> void *reg_cache;
> diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
> index 83f1190..49532d9 100644
> --- a/sound/soc/soc-core.c
> +++ b/sound/soc/soc-core.c
> @@ -970,10 +970,16 @@ static ssize_t codec_reg_show(struct device *dev,
> step = codec->reg_cache_step;
>
> count += sprintf(buf, "%s registers\n", codec->name);
> - for (i = 0; i < codec->reg_cache_size; i += step)
> - count += sprintf(buf + count, "%2x: %4x\n", i,
> - codec->read(codec, i));
> -
> + for (i = 0; i < codec->reg_cache_size; i += step) {
> + count += sprintf(buf + count, "%2x: ", i);
> + if (codec->display_register)
> + count += codec->display_register(codec,
> + buf + count, i);
> + else
> + count += sprintf(buf + count, "%4x",
> + codec->read(codec, i));
> + count += sprintf(buf + count, "\n");
> + }
> return count;
> }
> static DEVICE_ATTR(codec_reg, 0444, codec_reg_show, NULL);
>
> --
> 1.5.6.3
>
>
--
Jon Smirl
jonsmirl@xxxxxxxxx
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