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 86 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 87 if (!priv) 88 return -ENOMEM; 89 90 dev_set_drvdata(dev, priv); 91 92 priv->gpiod_mux = devm_gpiod_get(dev, "mux", GPIOD_OUT_LOW); 93 if (IS_ERR(priv->gpiod_mux)) 94 return dev_err_probe(dev, PTR_ERR(priv->gpiod_mux), 95 "Failed to get 'mux' gpio"); 96 97 return devm_snd_soc_register_component(dev, &simple_mux_component_driver, NULL, 0); 98 } 99 100 #ifdef CONFIG_OF 101 static const struct of_device_id simple_mux_ids[] = { 102 { .compatible = "simple-audio-mux", }, 103 { } 104 }; 105 MODULE_DEVICE_TABLE(of, simple_mux_ids); 106 #endif 107 108 static struct platform_driver simple_mux_driver = { 109 .driver = { 110 .name = "simple-mux", 111 .of_match_table = of_match_ptr(simple_mux_ids), 112 }, 113 .probe = simple_mux_probe, 114 }; 115 116 module_platform_driver(simple_mux_driver); 117 118 MODULE_DESCRIPTION("ASoC Simple Audio Mux driver"); 119 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>"); 120 MODULE_LICENSE("GPL"); 121