1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2020 Bootlin SA
4 * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
5 */
6
7#include <linux/gpio/consumer.h>
8#include <linux/module.h>
9#include <linux/regulator/consumer.h>
10#include <sound/soc.h>
11
12struct simple_mux {
13	struct gpio_desc *gpiod_mux;
14	unsigned int mux;
15};
16
17static const char * const simple_mux_texts[] = {
18	"Input 1", "Input 2"
19};
20
21static SOC_ENUM_SINGLE_EXT_DECL(simple_mux_enum, simple_mux_texts);
22
23static int simple_mux_control_get(struct snd_kcontrol *kcontrol,
24				  struct snd_ctl_elem_value *ucontrol)
25{
26	struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
27	struct snd_soc_component *c = snd_soc_dapm_to_component(dapm);
28	struct simple_mux *priv = snd_soc_component_get_drvdata(c);
29
30	ucontrol->value.enumerated.item[0] = priv->mux;
31
32	return 0;
33}
34
35static int simple_mux_control_put(struct snd_kcontrol *kcontrol,
36				  struct snd_ctl_elem_value *ucontrol)
37{
38	struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
39	struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
40	struct snd_soc_component *c = snd_soc_dapm_to_component(dapm);
41	struct simple_mux *priv = snd_soc_component_get_drvdata(c);
42
43	if (ucontrol->value.enumerated.item[0] > e->items)
44		return -EINVAL;
45
46	if (priv->mux == ucontrol->value.enumerated.item[0])
47		return 0;
48
49	priv->mux = ucontrol->value.enumerated.item[0];
50
51	gpiod_set_value_cansleep(priv->gpiod_mux, priv->mux);
52
53	return snd_soc_dapm_mux_update_power(dapm, kcontrol,
54					     ucontrol->value.enumerated.item[0],
55					     e, NULL);
56}
57
58static unsigned int simple_mux_read(struct snd_soc_component *component,
59				    unsigned int reg)
60{
61	struct simple_mux *priv = snd_soc_component_get_drvdata(component);
62
63	return priv->mux;
64}
65
66static const struct snd_kcontrol_new simple_mux_mux =
67	SOC_DAPM_ENUM_EXT("Muxer", simple_mux_enum, simple_mux_control_get, simple_mux_control_put);
68
69static const struct snd_soc_dapm_widget simple_mux_dapm_widgets[] = {
70	SND_SOC_DAPM_INPUT("IN1"),
71	SND_SOC_DAPM_INPUT("IN2"),
72	SND_SOC_DAPM_MUX("MUX", SND_SOC_NOPM, 0, 0, &simple_mux_mux),
73	SND_SOC_DAPM_OUTPUT("OUT"),
74};
75
76static const struct snd_soc_dapm_route simple_mux_dapm_routes[] = {
77	{ "OUT", NULL, "MUX" },
78	{ "MUX", "Input 1", "IN1" },
79	{ "MUX", "Input 2", "IN2" },
80};
81
82static const struct snd_soc_component_driver simple_mux_component_driver = {
83	.dapm_widgets		= simple_mux_dapm_widgets,
84	.num_dapm_widgets	= ARRAY_SIZE(simple_mux_dapm_widgets),
85	.dapm_routes		= simple_mux_dapm_routes,
86	.num_dapm_routes	= ARRAY_SIZE(simple_mux_dapm_routes),
87	.read			= simple_mux_read,
88};
89
90static int simple_mux_probe(struct platform_device *pdev)
91{
92	struct device *dev = &pdev->dev;
93	struct simple_mux *priv;
94
95	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
96	if (!priv)
97		return -ENOMEM;
98
99	dev_set_drvdata(dev, priv);
100
101	priv->gpiod_mux = devm_gpiod_get(dev, "mux", GPIOD_OUT_LOW);
102	if (IS_ERR(priv->gpiod_mux))
103		return dev_err_probe(dev, PTR_ERR(priv->gpiod_mux),
104				     "Failed to get 'mux' gpio");
105
106	return devm_snd_soc_register_component(dev, &simple_mux_component_driver, NULL, 0);
107}
108
109#ifdef CONFIG_OF
110static const struct of_device_id simple_mux_ids[] = {
111	{ .compatible = "simple-audio-mux", },
112	{ }
113};
114MODULE_DEVICE_TABLE(of, simple_mux_ids);
115#endif
116
117static struct platform_driver simple_mux_driver = {
118	.driver = {
119		.name = "simple-mux",
120		.of_match_table = of_match_ptr(simple_mux_ids),
121	},
122	.probe = simple_mux_probe,
123};
124
125module_platform_driver(simple_mux_driver);
126
127MODULE_DESCRIPTION("ASoC Simple Audio Mux driver");
128MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
129MODULE_LICENSE("GPL");
130