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 <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 struct simple_mux {
  13         struct gpio_desc *gpiod_mux;
  14         unsigned int mux;
  15 };
  16
  17 static const char * const simple_mux_texts[] = {
  18         "Input 1", "Input 2"
  19 };
  20
  21 static SOC_ENUM_SINGLE_EXT_DECL(simple_mux_enum, simple_mux_texts);
  22
  23 static 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
  35 static 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
  58 static 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
  66 static 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
  69 static 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
  76 static 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
  82 static 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
  90 static 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
 110 static const struct of_device_id simple_mux_ids[] = {
 111         { .compatible = "simple-audio-mux", },
 112         { }
 113 };
 114 MODULE_DEVICE_TABLE(of, simple_mux_ids);
 115 #endif
 116
 117 static 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
 125 module_platform_driver(simple_mux_driver);
 126
 127 MODULE_DESCRIPTION("ASoC Simple Audio Mux driver");
 128 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
 129 MODULE_LICENSE("GPL");