sound/soc/codecs/simple-mux.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2020 Bootlin SA
   4  * Author: Alexandre Belloni <[email protected]>
   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 <[email protected]>");
 154 MODULE_LICENSE("GPL");