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/mux/driver.h>
10#include <linux/regulator/consumer.h>
11#include <sound/soc.h>
12
13#define MUX_TEXT_SIZE 2
14#define MUX_WIDGET_SIZE 4
15#define MUX_ROUTE_SIZE 3
16struct simple_mux {
17 struct gpio_desc *gpiod_mux;
18 unsigned int mux;
19 const char *mux_texts[MUX_TEXT_SIZE];
20 unsigned int idle_state;
21 struct soc_enum mux_enum;
22 struct snd_kcontrol_new mux_mux;
23 struct snd_soc_dapm_widget mux_widgets[MUX_WIDGET_SIZE];
24 struct snd_soc_dapm_route mux_routes[MUX_ROUTE_SIZE];
25 struct snd_soc_component_driver mux_driver;
26};
27
28static const char * const simple_mux_texts[MUX_TEXT_SIZE] = {
29 "Input 1", "Input 2"
30};
31
32static SOC_ENUM_SINGLE_EXT_DECL(simple_mux_enum, simple_mux_texts);
33
34static int simple_mux_control_get(struct snd_kcontrol *kcontrol,
35 struct snd_ctl_elem_value *ucontrol)
36{
37 struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
38 struct snd_soc_component *c = snd_soc_dapm_to_component(dapm);
39 struct simple_mux *priv = snd_soc_component_get_drvdata(c);
40
41 ucontrol->value.enumerated.item[0] = priv->mux;
42
43 return 0;
44}
45
46static int simple_mux_control_put(struct snd_kcontrol *kcontrol,
47 struct snd_ctl_elem_value *ucontrol)
48{
49 struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
50 struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
51 struct snd_soc_component *c = snd_soc_dapm_to_component(dapm);
52 struct simple_mux *priv = snd_soc_component_get_drvdata(c);
53
54 if (ucontrol->value.enumerated.item[0] > e->items)
55 return -EINVAL;
56
57 if (priv->mux == ucontrol->value.enumerated.item[0])
58 return 0;
59
60 priv->mux = ucontrol->value.enumerated.item[0];
61
62 if (priv->idle_state != MUX_IDLE_AS_IS && dapm->bias_level < SND_SOC_BIAS_PREPARE)
63 return 0;
64
65 gpiod_set_value_cansleep(desc: priv->gpiod_mux, value: priv->mux);
66
67 return snd_soc_dapm_mux_update_power(dapm, kcontrol,
68 mux: ucontrol->value.enumerated.item[0],
69 e, NULL);
70}
71
72static unsigned int simple_mux_read(struct snd_soc_component *component,
73 unsigned int reg)
74{
75 struct simple_mux *priv = snd_soc_component_get_drvdata(c: component);
76
77 return priv->mux;
78}
79
80static const struct snd_kcontrol_new simple_mux_mux =
81 SOC_DAPM_ENUM_EXT("Muxer", simple_mux_enum, simple_mux_control_get, simple_mux_control_put);
82
83static int simple_mux_event(struct snd_soc_dapm_widget *w,
84 struct snd_kcontrol *kcontrol, int event)
85{
86 struct snd_soc_component *c = snd_soc_dapm_to_component(dapm: w->dapm);
87 struct simple_mux *priv = snd_soc_component_get_drvdata(c);
88
89 if (priv->idle_state != MUX_IDLE_AS_IS) {
90 switch (event) {
91 case SND_SOC_DAPM_PRE_PMU:
92 gpiod_set_value_cansleep(desc: priv->gpiod_mux, value: priv->mux);
93 break;
94 case SND_SOC_DAPM_POST_PMD:
95 gpiod_set_value_cansleep(desc: priv->gpiod_mux, value: priv->idle_state);
96 break;
97 default:
98 break;
99 }
100 }
101
102 return 0;
103}
104
105static const struct snd_soc_dapm_widget simple_mux_dapm_widgets[MUX_WIDGET_SIZE] = {
106 SND_SOC_DAPM_INPUT("IN1"),
107 SND_SOC_DAPM_INPUT("IN2"),
108 SND_SOC_DAPM_MUX_E("MUX", SND_SOC_NOPM, 0, 0, &simple_mux_mux, // see simple_mux_probe()
109 simple_mux_event, SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMD),
110 SND_SOC_DAPM_OUTPUT("OUT"),
111};
112
113static const struct snd_soc_dapm_route simple_mux_dapm_routes[MUX_ROUTE_SIZE] = {
114 { "OUT", NULL, "MUX" },
115 { "MUX", "Input 1", "IN1" }, // see simple_mux_probe()
116 { "MUX", "Input 2", "IN2" }, // see simple_mux_probe()
117};
118
119static int simple_mux_probe(struct platform_device *pdev)
120{
121 struct device *dev = &pdev->dev;
122 struct device_node *np = dev->of_node;
123 struct simple_mux *priv;
124 int ret;
125
126 priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL);
127 if (!priv)
128 return -ENOMEM;
129
130 dev_set_drvdata(dev, data: priv);
131
132 priv->gpiod_mux = devm_gpiod_get(dev, con_id: "mux", flags: GPIOD_OUT_LOW);
133 if (IS_ERR(ptr: priv->gpiod_mux))
134 return dev_err_probe(dev, err: PTR_ERR(ptr: priv->gpiod_mux),
135 fmt: "Failed to get 'mux' gpio");
136
137 /* Copy default settings */
138 memcpy(&priv->mux_texts, &simple_mux_texts, sizeof(priv->mux_texts));
139 memcpy(&priv->mux_enum, &simple_mux_enum, sizeof(priv->mux_enum));
140 memcpy(&priv->mux_mux, &simple_mux_mux, sizeof(priv->mux_mux));
141 memcpy(&priv->mux_widgets, &simple_mux_dapm_widgets, sizeof(priv->mux_widgets));
142 memcpy(&priv->mux_routes, &simple_mux_dapm_routes, sizeof(priv->mux_routes));
143
144 priv->mux_driver.dapm_widgets = priv->mux_widgets;
145 priv->mux_driver.num_dapm_widgets = MUX_WIDGET_SIZE;
146 priv->mux_driver.dapm_routes = priv->mux_routes;
147 priv->mux_driver.num_dapm_routes = MUX_ROUTE_SIZE;
148 priv->mux_driver.read = simple_mux_read;
149
150 /* Overwrite text ("Input 1", "Input 2") if property exists */
151 of_property_read_string_array(np, propname: "state-labels", out_strs: priv->mux_texts, MUX_TEXT_SIZE);
152
153 ret = of_property_read_u32(np, propname: "idle-state", out_value: &priv->idle_state);
154 if (ret < 0) {
155 priv->idle_state = MUX_IDLE_AS_IS;
156 } else if (priv->idle_state != MUX_IDLE_AS_IS && priv->idle_state >= 2) {
157 dev_err(dev, "invalid idle-state %u\n", priv->idle_state);
158 return -EINVAL;
159 }
160
161 /* switch to use priv data instead of default */
162 priv->mux_enum.texts = priv->mux_texts;
163 priv->mux_mux.private_value = (unsigned long)&priv->mux_enum;
164 priv->mux_widgets[2].kcontrol_news = &priv->mux_mux;
165 priv->mux_routes[1].control = priv->mux_texts[0]; // "Input 1"
166 priv->mux_routes[2].control = priv->mux_texts[1]; // "Input 2"
167
168 return devm_snd_soc_register_component(dev, component_driver: &priv->mux_driver, NULL, num_dai: 0);
169}
170
171#ifdef CONFIG_OF
172static const struct of_device_id simple_mux_ids[] = {
173 { .compatible = "simple-audio-mux", },
174 { }
175};
176MODULE_DEVICE_TABLE(of, simple_mux_ids);
177#endif
178
179static struct platform_driver simple_mux_driver = {
180 .driver = {
181 .name = "simple-mux",
182 .of_match_table = of_match_ptr(simple_mux_ids),
183 },
184 .probe = simple_mux_probe,
185};
186
187module_platform_driver(simple_mux_driver);
188
189MODULE_DESCRIPTION("ASoC Simple Audio Mux driver");
190MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
191MODULE_LICENSE("GPL");
192

source code of linux/sound/soc/codecs/simple-mux.c