sound/soc/codecs/lm4857.c

Source file repositories/reference/linux-study-clean/sound/soc/codecs/lm4857.c

File Facts

System
Linux kernel
Corpus path
sound/soc/codecs/lm4857.c
Extension
.c
Size
3783 bytes
Lines
149
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
/*
 * LM4857 AMP driver
 *
 * Copyright 2007 Wolfson Microelectronics PLC.
 * Author: Graeme Gregory
 *         graeme.gregory@wolfsonmicro.com
 * Copyright 2011 Lars-Peter Clausen <lars@metafoo.de>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#include <sound/core.h>
#include <sound/soc.h>
#include <sound/tlv.h>

static const struct reg_default lm4857_default_regs[] = {
	{ 0x0, 0x00 },
	{ 0x1, 0x00 },
	{ 0x2, 0x00 },
	{ 0x3, 0x00 },
};

/* The register offsets in the cache array */
#define LM4857_MVOL 0
#define LM4857_LVOL 1
#define LM4857_RVOL 2
#define LM4857_CTRL 3

/* the shifts required to set these bits */
#define LM4857_3D 5
#define LM4857_WAKEUP 5
#define LM4857_EPGAIN 4

static const unsigned int lm4857_mode_values[] = {
	0,
	6,
	7,
	8,
	9,
};

static const char * const lm4857_mode_texts[] = {
	"Off",
	"Earpiece",
	"Loudspeaker",
	"Loudspeaker + Headphone",
	"Headphone",
};

static SOC_VALUE_ENUM_SINGLE_AUTODISABLE_DECL(lm4857_mode_enum,
	LM4857_CTRL, 0, 0xf, lm4857_mode_texts, lm4857_mode_values);

static const struct snd_kcontrol_new lm4857_mode_ctrl =
	SOC_DAPM_ENUM("Mode", lm4857_mode_enum);

static const struct snd_soc_dapm_widget lm4857_dapm_widgets[] = {
	SND_SOC_DAPM_INPUT("IN"),

	SND_SOC_DAPM_DEMUX("Mode", SND_SOC_NOPM, 0, 0, &lm4857_mode_ctrl),

	SND_SOC_DAPM_OUTPUT("LS"),
	SND_SOC_DAPM_OUTPUT("HP"),
	SND_SOC_DAPM_OUTPUT("EP"),
};

static const DECLARE_TLV_DB_SCALE(stereo_tlv, -4050, 150, 0);
static const DECLARE_TLV_DB_SCALE(mono_tlv, -3450, 150, 0);

static const struct snd_kcontrol_new lm4857_controls[] = {
	SOC_SINGLE_TLV("Left Playback Volume", LM4857_LVOL, 0, 31, 0,
		stereo_tlv),
	SOC_SINGLE_TLV("Right Playback Volume", LM4857_RVOL, 0, 31, 0,
		stereo_tlv),
	SOC_SINGLE_TLV("Mono Playback Volume", LM4857_MVOL, 0, 31, 0,
		mono_tlv),
	SOC_SINGLE("Spk 3D Playback Switch", LM4857_LVOL, LM4857_3D, 1, 0),
	SOC_SINGLE("HP 3D Playback Switch", LM4857_RVOL, LM4857_3D, 1, 0),
	SOC_SINGLE("Fast Wakeup Playback Switch", LM4857_CTRL,
		LM4857_WAKEUP, 1, 0),
	SOC_SINGLE("Earpiece 6dB Playback Switch", LM4857_CTRL,
		LM4857_EPGAIN, 1, 0),
};

static const struct snd_soc_dapm_route lm4857_routes[] = {
	{ "Mode", NULL, "IN" },

Annotation

Implementation Notes