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/mux/driver.h> 10 #include <linux/regulator/consumer.h> 11 #include <sound/soc.h> 12 13 #define MUX_TEXT_SIZE 2 14 #define MUX_WIDGET_SIZE 4 15 #define MUX_ROUTE_SIZE 3 16 struct simple_mux { 17 struct gpio_desc *gpiod_mux; 18 unsigned int mux; 19 const char *mux_texts[MUX_TEXT_SIZE]; 20 unsigned int idle_state; 21 struct soc_enum mux_enum; 22 struct snd_kcontrol_new mux_mux; 23 struct snd_soc_dapm_widget mux_widgets[MUX_WIDGET_SIZE]; 24 struct snd_soc_dapm_route mux_routes[MUX_ROUTE_SIZE]; 25 struct snd_soc_component_driver mux_driver; 26 }; 27 28 static const char * const simple_mux_texts[MUX_TEXT_SIZE] = { 29 "Input 1", "Input 2" 30 }; 31 32 static SOC_ENUM_SINGLE_EXT_DECL(simple_mux_enum, simple_mux_texts); 33 34 static int simple_mux_control_get(struct snd_kcontrol *kcontrol, 35 struct snd_ctl_elem_value *ucontrol) 36 { 37 struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol); 38 struct snd_soc_component *c = snd_soc_dapm_to_component(dapm); 39 struct simple_mux *priv = snd_soc_component_get_drvdata(c); 40 41 ucontrol->value.enumerated.item[0] = priv->mux; 42 43 return 0; 44 } 45 46 static int simple_mux_control_put(struct snd_kcontrol *kcontrol, 47 struct snd_ctl_elem_value *ucontrol) 48 { 49 struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol); 50 struct soc_enum *e = (struct soc_enum *)kcontrol->private_value; 51 struct snd_soc_component *c = snd_soc_dapm_to_component(dapm); 52 struct simple_mux *priv = snd_soc_component_get_drvdata(c); 53 54 if (ucontrol->value.enumerated.item[0] > e->items) 55 return -EINVAL; 56 57 if (priv->mux == ucontrol->value.enumerated.item[0]) 58 return 0; 59 60 priv->mux = ucontrol->value.enumerated.item[0]; 61 62 if (priv->idle_state != MUX_IDLE_AS_IS && dapm->bias_level < SND_SOC_BIAS_PREPARE) 63 return 0; 64 65 gpiod_set_value_cansleep(priv->gpiod_mux, priv->mux); 66 67 return snd_soc_dapm_mux_update_power(dapm, kcontrol, 68 ucontrol->value.enumerated.item[0], 69 e, NULL); 70 } 71 72 static unsigned int simple_mux_read(struct snd_soc_component *component, 73 unsigned int reg) 74 { 75 struct simple_mux *priv = snd_soc_component_get_drvdata(component); 76 77 return priv->mux; 78 } 79 80 static const struct snd_kcontrol_new simple_mux_mux = 81 SOC_DAPM_ENUM_EXT("Muxer", simple_mux_enum, simple_mux_control_get, simple_mux_control_put); 82 83 static int simple_mux_event(struct snd_soc_dapm_widget *w, 84 struct snd_kcontrol *kcontrol, int event) 85 { 86 struct snd_soc_component *c = snd_soc_dapm_to_component(w->dapm); 87 struct simple_mux *priv = snd_soc_component_get_drvdata(c); 88 89 if (priv->idle_state != MUX_IDLE_AS_IS) { 90 switch (event) { 91 case SND_SOC_DAPM_PRE_PMU: 92 gpiod_set_value_cansleep(priv->gpiod_mux, priv->mux); 93 break; 94 case SND_SOC_DAPM_POST_PMD: 95 gpiod_set_value_cansleep(priv->gpiod_mux, priv->idle_state); 96 break; 97 default: 98 break; 99 } 100 } 101 102 return 0; 103 } 104 105 static const struct snd_soc_dapm_widget simple_mux_dapm_widgets[MUX_WIDGET_SIZE] = { 106 SND_SOC_DAPM_INPUT("IN1"), 107 SND_SOC_DAPM_INPUT("IN2"), 108 SND_SOC_DAPM_MUX_E("MUX", SND_SOC_NOPM, 0, 0, &simple_mux_mux, // see simple_mux_probe() 109 simple_mux_event, SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMD), 110 SND_SOC_DAPM_OUTPUT("OUT"), 111 }; 112 113 static const struct snd_soc_dapm_route simple_mux_dapm_routes[MUX_ROUTE_SIZE] = { 114 { "OUT", NULL, "MUX" }, 115 { "MUX", "Input 1", "IN1" }, // see simple_mux_probe() 116 { "MUX", "Input 2", "IN2" }, // see simple_mux_probe() 117 }; 118 119 static int simple_mux_probe(struct platform_device *pdev) 120 { 121 struct device *dev = &pdev->dev; 122 struct device_node *np = dev->of_node; 123 struct simple_mux *priv; 124 int ret; 125 126 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 127 if (!priv) 128 return -ENOMEM; 129 130 dev_set_drvdata(dev, priv); 131 132 priv->gpiod_mux = devm_gpiod_get(dev, "mux", GPIOD_OUT_LOW); 133 if (IS_ERR(priv->gpiod_mux)) 134 return dev_err_probe(dev, PTR_ERR(priv->gpiod_mux), 135 "Failed to get 'mux' gpio"); 136 137 /* Copy default settings */ 138 memcpy(&priv->mux_texts, &simple_mux_texts, sizeof(priv->mux_texts)); 139 memcpy(&priv->mux_enum, &simple_mux_enum, sizeof(priv->mux_enum)); 140 memcpy(&priv->mux_mux, &simple_mux_mux, sizeof(priv->mux_mux)); 141 memcpy(&priv->mux_widgets, &simple_mux_dapm_widgets, sizeof(priv->mux_widgets)); 142 memcpy(&priv->mux_routes, &simple_mux_dapm_routes, sizeof(priv->mux_routes)); 143 144 priv->mux_driver.dapm_widgets = priv->mux_widgets; 145 priv->mux_driver.num_dapm_widgets = MUX_WIDGET_SIZE; 146 priv->mux_driver.dapm_routes = priv->mux_routes; 147 priv->mux_driver.num_dapm_routes = MUX_ROUTE_SIZE; 148 priv->mux_driver.read = simple_mux_read; 149 150 /* Overwrite text ("Input 1", "Input 2") if property exists */ 151 of_property_read_string_array(np, "state-labels", priv->mux_texts, MUX_TEXT_SIZE); 152 153 ret = of_property_read_u32(np, "idle-state", &priv->idle_state); 154 if (ret < 0) { 155 priv->idle_state = MUX_IDLE_AS_IS; 156 } else if (priv->idle_state != MUX_IDLE_AS_IS && priv->idle_state >= 2) { 157 dev_err(dev, "invalid idle-state %u\n", priv->idle_state); 158 return -EINVAL; 159 } 160 161 /* switch to use priv data instead of default */ 162 priv->mux_enum.texts = priv->mux_texts; 163 priv->mux_mux.private_value = (unsigned long)&priv->mux_enum; 164 priv->mux_widgets[2].kcontrol_news = &priv->mux_mux; 165 priv->mux_routes[1].control = priv->mux_texts[0]; // "Input 1" 166 priv->mux_routes[2].control = priv->mux_texts[1]; // "Input 2" 167 168 return devm_snd_soc_register_component(dev, &priv->mux_driver, NULL, 0); 169 } 170 171 #ifdef CONFIG_OF 172 static const struct of_device_id simple_mux_ids[] = { 173 { .compatible = "simple-audio-mux", }, 174 { } 175 }; 176 MODULE_DEVICE_TABLE(of, simple_mux_ids); 177 #endif 178 179 static struct platform_driver simple_mux_driver = { 180 .driver = { 181 .name = "simple-mux", 182 .of_match_table = of_match_ptr(simple_mux_ids), 183 }, 184 .probe = simple_mux_probe, 185 }; 186 187 module_platform_driver(simple_mux_driver); 188 189 MODULE_DESCRIPTION("ASoC Simple Audio Mux driver"); 190 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>"); 191 MODULE_LICENSE("GPL"); 192