At Fri, 18 Jul 2008 11:23:09 -0400,
Jon Smirl wrote:
>
> 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.
Yes, I agree. For non-standard register maps, provide its own
codec_reg_show().
> Might want to add another parameter for cached/uncached. Then we could
> make a debug option to add the non-cached display.
That makes sense, too.
> 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.
Right. So far, it's been OK since the number of registers is
relatively small.
Takashi
> > 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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