Commit 58cd33c0 authored by Mark Brown's avatar Mark Brown Committed by Jaroslav Kysela
Browse files

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: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Signed-off-by: default avatarJaroslav Kysela <perex@perex.cz>
parent 8a33de9e

include/sound/soc.h

+2 −0
Original line number Diff line number Diff line
@@ -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;

sound/soc/soc-core.c

+23 −3
Original line number Diff line number Diff line
@@ -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;

}

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