ALSA: ASoC: Allow codecs to override register display

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.

Also ensure that we don't overflow PAGE_SIZE while writing out the
register dump.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Mark Brown 2008-07-29 11:42:25 +01:00 committed by Jaroslav Kysela
parent 8a33de9e51
commit 58cd33c0f3
2 changed files with 25 additions and 3 deletions

View File

@ -410,6 +410,8 @@ 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 *,
size_t, unsigned int);
hw_write_t hw_write;
hw_read_t hw_read;
void *reg_cache;

View File

@ -970,9 +970,29 @@ 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 (count >= PAGE_SIZE - 1)
break;
if (codec->display_register)
count += codec->display_register(codec, buf + count,
PAGE_SIZE - count, i);
else
count += snprintf(buf + count, PAGE_SIZE - count,
"%4x", codec->read(codec, i));
if (count >= PAGE_SIZE - 1)
break;
count += snprintf(buf + count, PAGE_SIZE - count, "\n");
if (count >= PAGE_SIZE - 1)
break;
}
/* Truncate count; min() would cause a warning */
if (count >= PAGE_SIZE)
count = PAGE_SIZE - 1;
return count;
}