simple-mux.c 3.4 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (c) 2020 Bootlin SA
  4. * Author: Alexandre Belloni <[email protected]>
  5. */
  6. #include <linux/gpio/consumer.h>
  7. #include <linux/module.h>
  8. #include <linux/regulator/consumer.h>
  9. #include <sound/soc.h>
  10. struct simple_mux {
  11. struct gpio_desc *gpiod_mux;
  12. unsigned int mux;
  13. };
  14. static const char * const simple_mux_texts[] = {
  15. "Input 1", "Input 2"
  16. };
  17. static SOC_ENUM_SINGLE_EXT_DECL(simple_mux_enum, simple_mux_texts);
  18. static int simple_mux_control_get(struct snd_kcontrol *kcontrol,
  19. struct snd_ctl_elem_value *ucontrol)
  20. {
  21. struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
  22. struct snd_soc_component *c = snd_soc_dapm_to_component(dapm);
  23. struct simple_mux *priv = snd_soc_component_get_drvdata(c);
  24. ucontrol->value.enumerated.item[0] = priv->mux;
  25. return 0;
  26. }
  27. static int simple_mux_control_put(struct snd_kcontrol *kcontrol,
  28. struct snd_ctl_elem_value *ucontrol)
  29. {
  30. struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
  31. struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
  32. struct snd_soc_component *c = snd_soc_dapm_to_component(dapm);
  33. struct simple_mux *priv = snd_soc_component_get_drvdata(c);
  34. if (ucontrol->value.enumerated.item[0] > e->items)
  35. return -EINVAL;
  36. if (priv->mux == ucontrol->value.enumerated.item[0])
  37. return 0;
  38. priv->mux = ucontrol->value.enumerated.item[0];
  39. gpiod_set_value_cansleep(priv->gpiod_mux, priv->mux);
  40. return snd_soc_dapm_mux_update_power(dapm, kcontrol,
  41. ucontrol->value.enumerated.item[0],
  42. e, NULL);
  43. }
  44. static const struct snd_kcontrol_new simple_mux_mux =
  45. SOC_DAPM_ENUM_EXT("Muxer", simple_mux_enum, simple_mux_control_get, simple_mux_control_put);
  46. static const struct snd_soc_dapm_widget simple_mux_dapm_widgets[] = {
  47. SND_SOC_DAPM_INPUT("IN1"),
  48. SND_SOC_DAPM_INPUT("IN2"),
  49. SND_SOC_DAPM_MUX("MUX", SND_SOC_NOPM, 0, 0, &simple_mux_mux),
  50. SND_SOC_DAPM_OUTPUT("OUT"),
  51. };
  52. static const struct snd_soc_dapm_route simple_mux_dapm_routes[] = {
  53. { "OUT", NULL, "MUX" },
  54. { "MUX", "Input 1", "IN1" },
  55. { "MUX", "Input 2", "IN2" },
  56. };
  57. static const struct snd_soc_component_driver simple_mux_component_driver = {
  58. .dapm_widgets = simple_mux_dapm_widgets,
  59. .num_dapm_widgets = ARRAY_SIZE(simple_mux_dapm_widgets),
  60. .dapm_routes = simple_mux_dapm_routes,
  61. .num_dapm_routes = ARRAY_SIZE(simple_mux_dapm_routes),
  62. };
  63. static int simple_mux_probe(struct platform_device *pdev)
  64. {
  65. struct device *dev = &pdev->dev;
  66. struct simple_mux *priv;
  67. priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  68. if (!priv)
  69. return -ENOMEM;
  70. dev_set_drvdata(dev, priv);
  71. priv->gpiod_mux = devm_gpiod_get(dev, "mux", GPIOD_OUT_LOW);
  72. if (IS_ERR(priv->gpiod_mux))
  73. return dev_err_probe(dev, PTR_ERR(priv->gpiod_mux),
  74. "Failed to get 'mux' gpio");
  75. return devm_snd_soc_register_component(dev, &simple_mux_component_driver, NULL, 0);
  76. }
  77. #ifdef CONFIG_OF
  78. static const struct of_device_id simple_mux_ids[] = {
  79. { .compatible = "simple-audio-mux", },
  80. { }
  81. };
  82. MODULE_DEVICE_TABLE(of, simple_mux_ids);
  83. #endif
  84. static struct platform_driver simple_mux_driver = {
  85. .driver = {
  86. .name = "simple-mux",
  87. .of_match_table = of_match_ptr(simple_mux_ids),
  88. },
  89. .probe = simple_mux_probe,
  90. };
  91. module_platform_driver(simple_mux_driver);
  92. MODULE_DESCRIPTION("ASoC Simple Audio Mux driver");
  93. MODULE_AUTHOR("Alexandre Belloni <[email protected]>");
  94. MODULE_LICENSE("GPL");