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/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");