sound/soc/codecs/simple-amplifier.c

   1 /*
   2  * Copyright (c) 2017 BayLibre, SAS.
   3  * Author: Jerome Brunet <jbrunet@baylibre.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  * The full GNU General Public License is included in this distribution
  17  * in the file called COPYING.
  18  */
  19
  20 #include <linux/gpio/consumer.h>
  21 #include <linux/module.h>
  22 #include <linux/regulator/consumer.h>
  23 #include <sound/soc.h>
  24
  25 #define DRV_NAME "simple-amplifier"
  26
  27 struct simple_amp {
  28         struct gpio_desc *gpiod_enable;
  29 };
  30
  31 static int drv_event(struct snd_soc_dapm_widget *w,
  32                      struct snd_kcontrol *control, int event)
  33 {
  34         struct snd_soc_component *c = snd_soc_dapm_to_component(w->dapm);
  35         struct simple_amp *priv = snd_soc_component_get_drvdata(c);
  36         int val;
  37
  38         switch (event) {
  39         case SND_SOC_DAPM_POST_PMU:
  40                 val = 1;
  41                 break;
  42         case SND_SOC_DAPM_PRE_PMD:
  43                 val = 0;
  44                 break;
  45         default:
  46                 WARN(1, "Unexpected event");
  47                 return -EINVAL;
  48         }
  49
  50         gpiod_set_value_cansleep(priv->gpiod_enable, val);
  51
  52         return 0;
  53 }
  54
  55 static const struct snd_soc_dapm_widget simple_amp_dapm_widgets[] = {
  56         SND_SOC_DAPM_INPUT("INL"),
  57         SND_SOC_DAPM_INPUT("INR"),
  58         SND_SOC_DAPM_OUT_DRV_E("DRV", SND_SOC_NOPM, 0, 0, NULL, 0, drv_event,
  59                                (SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD)),
  60         SND_SOC_DAPM_OUTPUT("OUTL"),
  61         SND_SOC_DAPM_OUTPUT("OUTR"),
  62         SND_SOC_DAPM_REGULATOR_SUPPLY("VCC", 20, 0),
  63 };
  64
  65 static const struct snd_soc_dapm_route simple_amp_dapm_routes[] = {
  66         { "DRV", NULL, "INL" },
  67         { "DRV", NULL, "INR" },
  68         { "OUTL", NULL, "VCC" },
  69         { "OUTR", NULL, "VCC" },
  70         { "OUTL", NULL, "DRV" },
  71         { "OUTR", NULL, "DRV" },
  72 };
  73
  74 static const struct snd_soc_component_driver simple_amp_component_driver = {
  75         .dapm_widgets           = simple_amp_dapm_widgets,
  76         .num_dapm_widgets       = ARRAY_SIZE(simple_amp_dapm_widgets),
  77         .dapm_routes            = simple_amp_dapm_routes,
  78         .num_dapm_routes        = ARRAY_SIZE(simple_amp_dapm_routes),
  79 };
  80
  81 static int simple_amp_probe(struct platform_device *pdev)
  82 {
  83         struct device *dev = &pdev->dev;
  84         struct simple_amp *priv;
  85         int err;
  86
  87         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  88         if (priv == NULL)
  89                 return -ENOMEM;
  90         platform_set_drvdata(pdev, priv);
  91
  92         priv->gpiod_enable = devm_gpiod_get_optional(dev, "enable",
  93                                                      GPIOD_OUT_LOW);
  94         if (IS_ERR(priv->gpiod_enable)) {
  95                 err = PTR_ERR(priv->gpiod_enable);
  96                 if (err != -EPROBE_DEFER)
  97                         dev_err(dev, "Failed to get 'enable' gpio: %d", err);
  98                 return err;
  99         }
 100
 101         return devm_snd_soc_register_component(dev,
 102                                                &simple_amp_component_driver,
 103                                                NULL, 0);
 104 }
 105
 106 #ifdef CONFIG_OF
 107 static const struct of_device_id simple_amp_ids[] = {
 108         { .compatible = "dioo,dio2125", },
 109         { .compatible = "simple-audio-amplifier", },
 110         { }
 111 };
 112 MODULE_DEVICE_TABLE(of, simple_amp_ids);
 113 #endif
 114
 115 static struct platform_driver simple_amp_driver = {
 116         .driver = {
 117                 .name = DRV_NAME,
 118                 .of_match_table = of_match_ptr(simple_amp_ids),
 119         },
 120         .probe = simple_amp_probe,
 121 };
 122
 123 module_platform_driver(simple_amp_driver);
 124
 125 MODULE_DESCRIPTION("ASoC Simple Audio Amplifier driver");
 126 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
 127 MODULE_LICENSE("GPL");