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 const struct snd_kcontrol_new simple_mux_mux =
  59         SOC_DAPM_ENUM_EXT("Muxer", simple_mux_enum, simple_mux_control_get, simple_mux_control_put);
  60
  61 static const struct snd_soc_dapm_widget simple_mux_dapm_widgets[] = {
  62         SND_SOC_DAPM_INPUT("IN1"),
  63         SND_SOC_DAPM_INPUT("IN2"),
  64         SND_SOC_DAPM_MUX("MUX", SND_SOC_NOPM, 0, 0, &simple_mux_mux),
  65         SND_SOC_DAPM_OUTPUT("OUT"),
  66 };
  67
  68 static const struct snd_soc_dapm_route simple_mux_dapm_routes[] = {
  69         { "OUT", NULL, "MUX" },
  70         { "MUX", "Input 1", "IN1" },
  71         { "MUX", "Input 2", "IN2" },
  72 };
  73
  74 static const struct snd_soc_component_driver simple_mux_component_driver = {
  75         .dapm_widgets           = simple_mux_dapm_widgets,
  76         .num_dapm_widgets       = ARRAY_SIZE(simple_mux_dapm_widgets),
  77         .dapm_routes            = simple_mux_dapm_routes,
  78         .num_dapm_routes        = ARRAY_SIZE(simple_mux_dapm_routes),
  79 };
  80
  81 static int simple_mux_probe(struct platform_device *pdev)
  82 {
  83         struct device *dev = &pdev->dev;
  84         struct simple_mux *priv;
  85         int err;
  86
  87         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  88         if (!priv)
  89                 return -ENOMEM;
  90
  91         dev_set_drvdata(dev, priv);
  92
  93         priv->gpiod_mux = devm_gpiod_get(dev, "mux", GPIOD_OUT_LOW);
  94         if (IS_ERR(priv->gpiod_mux)) {
  95                 err = PTR_ERR(priv->gpiod_mux);
  96                 if (err != -EPROBE_DEFER)
  97                         dev_err(dev, "Failed to get 'mux' gpio: %d", err);
  98                 return err;
  99         }
 100
 101         return devm_snd_soc_register_component(dev, &simple_mux_component_driver, NULL, 0);
 102 }
 103
 104 #ifdef CONFIG_OF
 105 static const struct of_device_id simple_mux_ids[] = {
 106         { .compatible = "simple-audio-mux", },
 107         { }
 108 };
 109 MODULE_DEVICE_TABLE(of, simple_mux_ids);
 110 #endif
 111
 112 static struct platform_driver simple_mux_driver = {
 113         .driver = {
 114                 .name = "simple-mux",
 115                 .of_match_table = of_match_ptr(simple_mux_ids),
 116         },
 117         .probe = simple_mux_probe,
 118 };
 119
 120 module_platform_driver(simple_mux_driver);
 121
 122 MODULE_DESCRIPTION("ASoC Simple Audio Mux driver");
 123 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
 124 MODULE_LICENSE("GPL");