root/sound/soc/codecs/simple-amplifier.c

DEFINITIONS

1. drv_event
2. simple_amp_probe

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2017 BayLibre, SAS.
   4  * Author: Jerome Brunet <jbrunet@baylibre.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 #define DRV_NAME "simple-amplifier"
  13 
  14 struct simple_amp {
  15         struct gpio_desc *gpiod_enable;
  16 };
  17 
  18 static int drv_event(struct snd_soc_dapm_widget *w,
  19                      struct snd_kcontrol *control, int event)
  20 {
  21         struct snd_soc_component *c = snd_soc_dapm_to_component(w->dapm);
  22         struct simple_amp *priv = snd_soc_component_get_drvdata(c);
  23         int val;
  24 
  25         switch (event) {
  26         case SND_SOC_DAPM_POST_PMU:
  27                 val = 1;
  28                 break;
  29         case SND_SOC_DAPM_PRE_PMD:
  30                 val = 0;
  31                 break;
  32         default:
  33                 WARN(1, "Unexpected event");
  34                 return -EINVAL;
  35         }
  36 
  37         gpiod_set_value_cansleep(priv->gpiod_enable, val);
  38 
  39         return 0;
  40 }
  41 
  42 static const struct snd_soc_dapm_widget simple_amp_dapm_widgets[] = {
  43         SND_SOC_DAPM_INPUT("INL"),
  44         SND_SOC_DAPM_INPUT("INR"),
  45         SND_SOC_DAPM_OUT_DRV_E("DRV", SND_SOC_NOPM, 0, 0, NULL, 0, drv_event,
  46                                (SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD)),
  47         SND_SOC_DAPM_OUTPUT("OUTL"),
  48         SND_SOC_DAPM_OUTPUT("OUTR"),
  49         SND_SOC_DAPM_REGULATOR_SUPPLY("VCC", 20, 0),
  50 };
  51 
  52 static const struct snd_soc_dapm_route simple_amp_dapm_routes[] = {
  53         { "DRV", NULL, "INL" },
  54         { "DRV", NULL, "INR" },
  55         { "OUTL", NULL, "VCC" },
  56         { "OUTR", NULL, "VCC" },
  57         { "OUTL", NULL, "DRV" },
  58         { "OUTR", NULL, "DRV" },
  59 };
  60 
  61 static const struct snd_soc_component_driver simple_amp_component_driver = {
  62         .dapm_widgets           = simple_amp_dapm_widgets,
  63         .num_dapm_widgets       = ARRAY_SIZE(simple_amp_dapm_widgets),
  64         .dapm_routes            = simple_amp_dapm_routes,
  65         .num_dapm_routes        = ARRAY_SIZE(simple_amp_dapm_routes),
  66 };
  67 
  68 static int simple_amp_probe(struct platform_device *pdev)
  69 {
  70         struct device *dev = &pdev->dev;
  71         struct simple_amp *priv;
  72         int err;
  73 
  74         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  75         if (priv == NULL)
  76                 return -ENOMEM;
  77         platform_set_drvdata(pdev, priv);
  78 
  79         priv->gpiod_enable = devm_gpiod_get_optional(dev, "enable",
  80                                                      GPIOD_OUT_LOW);
  81         if (IS_ERR(priv->gpiod_enable)) {
  82                 err = PTR_ERR(priv->gpiod_enable);
  83                 if (err != -EPROBE_DEFER)
  84                         dev_err(dev, "Failed to get 'enable' gpio: %d", err);
  85                 return err;
  86         }
  87 
  88         return devm_snd_soc_register_component(dev,
  89                                                &simple_amp_component_driver,
  90                                                NULL, 0);
  91 }
  92 
  93 #ifdef CONFIG_OF
  94 static const struct of_device_id simple_amp_ids[] = {
  95         { .compatible = "dioo,dio2125", },
  96         { .compatible = "simple-audio-amplifier", },
  97         { }
  98 };
  99 MODULE_DEVICE_TABLE(of, simple_amp_ids);
 100 #endif
 101 
 102 static struct platform_driver simple_amp_driver = {
 103         .driver = {
 104                 .name = DRV_NAME,
 105                 .of_match_table = of_match_ptr(simple_amp_ids),
 106         },
 107         .probe = simple_amp_probe,
 108 };
 109 
 110 module_platform_driver(simple_amp_driver);
 111 
 112 MODULE_DESCRIPTION("ASoC Simple Audio Amplifier driver");
 113 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
 114 MODULE_LICENSE("GPL");