sound/soc/codecs/ac97.c

Source file repositories/reference/linux-study-clean/sound/soc/codecs/ac97.c

File Facts

System
Linux kernel
Corpus path
sound/soc/codecs/ac97.c
Extension
.c
Size
3693 bytes
Lines
154
Domain
Driver Families
Bucket
sound/soc
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ac97.c  --  ALSA Soc AC97 codec support
 *
 * Copyright 2005 Wolfson Microelectronics PLC.
 * Author: Liam Girdwood <lrg@slimlogic.co.uk>
 *
 * Generic AC97 support.
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/of.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/ac97_codec.h>
#include <sound/initval.h>
#include <sound/soc.h>

static const struct snd_soc_dapm_widget ac97_widgets[] = {
	SND_SOC_DAPM_INPUT("RX"),
	SND_SOC_DAPM_OUTPUT("TX"),
};

static const struct snd_soc_dapm_route ac97_routes[] = {
	{ "AC97 Capture", NULL, "RX" },
	{ "TX", NULL, "AC97 Playback" },
};

static int ac97_prepare(struct snd_pcm_substream *substream,
			struct snd_soc_dai *dai)
{
	struct snd_soc_component *component = dai->component;
	struct snd_ac97 *ac97 = snd_soc_component_get_drvdata(component);

	int reg = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
		  AC97_PCM_FRONT_DAC_RATE : AC97_PCM_LR_ADC_RATE;
	return snd_ac97_set_rate(ac97, reg, substream->runtime->rate);
}

static const struct snd_soc_dai_ops ac97_dai_ops = {
	.prepare	= ac97_prepare,
};

static struct snd_soc_dai_driver ac97_dai = {
	.name = "ac97-hifi",
	.playback = {
		.stream_name = "AC97 Playback",
		.channels_min = 1,
		.channels_max = 2,
		.rates = SNDRV_PCM_RATE_KNOT,
		.formats = SND_SOC_STD_AC97_FMTS,},
	.capture = {
		.stream_name = "AC97 Capture",
		.channels_min = 1,
		.channels_max = 2,
		.rates = SNDRV_PCM_RATE_KNOT,
		.formats = SND_SOC_STD_AC97_FMTS,},
	.ops = &ac97_dai_ops,
};

static int ac97_soc_probe(struct snd_soc_component *component)
{
	struct snd_ac97 *ac97;
	struct snd_ac97_bus *ac97_bus;
	struct snd_ac97_template ac97_template;
	int ret;

	/* add codec as bus device for standard ac97 */
	ret = snd_ac97_bus(component->card->snd_card, 0, soc_ac97_ops,
			   NULL, &ac97_bus);
	if (ret < 0)
		return ret;

	memset(&ac97_template, 0, sizeof(struct snd_ac97_template));
	ret = snd_ac97_mixer(ac97_bus, &ac97_template, &ac97);
	if (ret < 0)
		return ret;

	snd_soc_component_set_drvdata(component, ac97);

	return 0;
}

#ifdef CONFIG_PM
static int ac97_soc_suspend(struct snd_soc_component *component)
{

Annotation

Implementation Notes