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
12 #define MUX_TEXT_SIZE 2
13 #define MUX_WIDGET_SIZE 4
14 #define MUX_ROUTE_SIZE 3
15 struct simple_mux {
16 struct gpio_desc *gpiod_mux;
17 unsigned int mux;
18 const char *mux_texts[MUX_TEXT_SIZE];
19 struct soc_enum mux_enum;
20 struct snd_kcontrol_new mux_mux;
21 struct snd_soc_dapm_widget mux_widgets[MUX_WIDGET_SIZE];
22 struct snd_soc_dapm_route mux_routes[MUX_ROUTE_SIZE];
23 struct snd_soc_component_driver mux_driver;
24 };
25
26 static const char * const simple_mux_texts[MUX_TEXT_SIZE] = {
27 "Input 1", "Input 2"
28 };
29
30 static SOC_ENUM_SINGLE_EXT_DECL(simple_mux_enum, simple_mux_texts);
31
32 static int simple_mux_control_get(struct snd_kcontrol *kcontrol,
33 struct snd_ctl_elem_value *ucontrol)
34 {
35 struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
36 struct snd_soc_component *c = snd_soc_dapm_to_component(dapm);
37 struct simple_mux *priv = snd_soc_component_get_drvdata(c);
38
39 ucontrol->value.enumerated.item[0] = priv->mux;
40
41 return 0;
42 }
43
44 static int simple_mux_control_put(struct snd_kcontrol *kcontrol,
45 struct snd_ctl_elem_value *ucontrol)
46 {
47 struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
48 struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
49 struct snd_soc_component *c = snd_soc_dapm_to_component(dapm);
50 struct simple_mux *priv = snd_soc_component_get_drvdata(c);
51
52 if (ucontrol->value.enumerated.item[0] > e->items)
53 return -EINVAL;
54
55 if (priv->mux == ucontrol->value.enumerated.item[0])
56 return 0;
57
58 priv->mux = ucontrol->value.enumerated.item[0];
59
60 gpiod_set_value_cansleep(priv->gpiod_mux, priv->mux);
61
62 return snd_soc_dapm_mux_update_power(dapm, kcontrol,
63 ucontrol->value.enumerated.item[0],
64 e, NULL);
65 }
66
67 static unsigned int simple_mux_read(struct snd_soc_component *component,
68 unsigned int reg)
69 {
70 struct simple_mux *priv = snd_soc_component_get_drvdata(component);
71
72 return priv->mux;
73 }
74
75 static const struct snd_kcontrol_new simple_mux_mux =
76 SOC_DAPM_ENUM_EXT("Muxer", simple_mux_enum, simple_mux_control_get, simple_mux_control_put);
77
78 static const struct snd_soc_dapm_widget simple_mux_dapm_widgets[MUX_WIDGET_SIZE] = {
79 SND_SOC_DAPM_INPUT("IN1"),
80 SND_SOC_DAPM_INPUT("IN2"),
81 SND_SOC_DAPM_MUX("MUX", SND_SOC_NOPM, 0, 0, &simple_mux_mux), // see simple_mux_probe()
82 SND_SOC_DAPM_OUTPUT("OUT"),
83 };
84
85 static const struct snd_soc_dapm_route simple_mux_dapm_routes[MUX_ROUTE_SIZE] = {
86 { "OUT", NULL, "MUX" },
87 { "MUX", "Input 1", "IN1" }, // see simple_mux_probe()
88 { "MUX", "Input 2", "IN2" }, // see simple_mux_probe()
89 };
90
91 static int simple_mux_probe(struct platform_device *pdev)
92 {
93 struct device *dev = &pdev->dev;
94 struct device_node *np = dev->of_node;
95 struct simple_mux *priv;
96
97 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
98 if (!priv)
99 return -ENOMEM;
100
101 dev_set_drvdata(dev, priv);
102
103 priv->gpiod_mux = devm_gpiod_get(dev, "mux", GPIOD_OUT_LOW);
104 if (IS_ERR(priv->gpiod_mux))
105 return dev_err_probe(dev, PTR_ERR(priv->gpiod_mux),
106 "Failed to get 'mux' gpio");
107
108 /* Copy default settings */
109 memcpy(&priv->mux_texts, &simple_mux_texts, sizeof(priv->mux_texts));
110 memcpy(&priv->mux_enum, &simple_mux_enum, sizeof(priv->mux_enum));
111 memcpy(&priv->mux_mux, &simple_mux_mux, sizeof(priv->mux_mux));
112 memcpy(&priv->mux_widgets, &simple_mux_dapm_widgets, sizeof(priv->mux_widgets));
113 memcpy(&priv->mux_routes, &simple_mux_dapm_routes, sizeof(priv->mux_routes));
114
115 priv->mux_driver.dapm_widgets = priv->mux_widgets;
116 priv->mux_driver.num_dapm_widgets = MUX_WIDGET_SIZE;
117 priv->mux_driver.dapm_routes = priv->mux_routes;
118 priv->mux_driver.num_dapm_routes = MUX_ROUTE_SIZE;
119 priv->mux_driver.read = simple_mux_read;
120
121 /* Overwrite text ("Input 1", "Input 2") if property exists */
122 of_property_read_string_array(np, "state-labels", priv->mux_texts, MUX_TEXT_SIZE);
123
124 /* switch to use priv data instead of default */
125 priv->mux_enum.texts = priv->mux_texts;
126 priv->mux_mux.private_value = (unsigned long)&priv->mux_enum;
127 priv->mux_widgets[2].kcontrol_news = &priv->mux_mux;
128 priv->mux_routes[1].control = priv->mux_texts[0]; // "Input 1"
129 priv->mux_routes[2].control = priv->mux_texts[1]; // "Input 2"
130
131 return devm_snd_soc_register_component(dev, &priv->mux_driver, NULL, 0);
132 }
133
134 #ifdef CONFIG_OF
135 static const struct of_device_id simple_mux_ids[] = {
136 { .compatible = "simple-audio-mux", },
137 { }
138 };
139 MODULE_DEVICE_TABLE(of, simple_mux_ids);
140 #endif
141
142 static struct platform_driver simple_mux_driver = {
143 .driver = {
144 .name = "simple-mux",
145 .of_match_table = of_match_ptr(simple_mux_ids),
146 },
147 .probe = simple_mux_probe,
148 };
149
150 module_platform_driver(simple_mux_driver);
151
152 MODULE_DESCRIPTION("ASoC Simple Audio Mux driver");
153 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
154 MODULE_LICENSE("GPL");
155
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