sound/soc/codecs/dmic.c

   1 /*
   2  * dmic.c  --  SoC audio for Generic Digital MICs
   3  *
   4  * Author: Liam Girdwood <lrg@slimlogic.co.uk>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * version 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  18  * 02110-1301 USA
  19  *
  20  */
  21
  22 #include <linux/delay.h>
  23 #include <linux/gpio.h>
  24 #include <linux/gpio/consumer.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/slab.h>
  27 #include <linux/module.h>
  28 #include <sound/core.h>
  29 #include <sound/pcm.h>
  30 #include <sound/soc.h>
  31 #include <sound/soc-dapm.h>
  32
  33 struct dmic {
  34         struct gpio_desc *gpio_en;
  35         int wakeup_delay;
  36 };
  37
  38 static int dmic_aif_event(struct snd_soc_dapm_widget *w,
  39                           struct snd_kcontrol *kcontrol, int event) {
  40         struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
  41         struct dmic *dmic = snd_soc_component_get_drvdata(component);
  42
  43         switch (event) {
  44         case SND_SOC_DAPM_POST_PMU:
  45                 if (dmic->gpio_en)
  46                         gpiod_set_value(dmic->gpio_en, 1);
  47
  48                 if (dmic->wakeup_delay)
  49                         msleep(dmic->wakeup_delay);
  50                 break;
  51         case SND_SOC_DAPM_POST_PMD:
  52                 if (dmic->gpio_en)
  53                         gpiod_set_value(dmic->gpio_en, 0);
  54                 break;
  55         }
  56
  57         return 0;
  58 }
  59
  60 static struct snd_soc_dai_driver dmic_dai = {
  61         .name = "dmic-hifi",
  62         .capture = {
  63                 .stream_name = "Capture",
  64                 .channels_min = 1,
  65                 .channels_max = 8,
  66                 .rates = SNDRV_PCM_RATE_CONTINUOUS,
  67                 .formats = SNDRV_PCM_FMTBIT_S32_LE
  68                         | SNDRV_PCM_FMTBIT_S24_LE
  69                         | SNDRV_PCM_FMTBIT_S16_LE,
  70         },
  71 };
  72
  73 static int dmic_component_probe(struct snd_soc_component *component)
  74 {
  75         struct dmic *dmic;
  76
  77         dmic = devm_kzalloc(component->dev, sizeof(*dmic), GFP_KERNEL);
  78         if (!dmic)
  79                 return -ENOMEM;
  80
  81         dmic->gpio_en = devm_gpiod_get_optional(component->dev,
  82                                                 "dmicen", GPIOD_OUT_LOW);
  83         if (IS_ERR(dmic->gpio_en))
  84                 return PTR_ERR(dmic->gpio_en);
  85
  86         device_property_read_u32(component->dev, "wakeup-delay-ms",
  87                                  &dmic->wakeup_delay);
  88
  89         snd_soc_component_set_drvdata(component, dmic);
  90
  91         return 0;
  92 }
  93
  94 static const struct snd_soc_dapm_widget dmic_dapm_widgets[] = {
  95         SND_SOC_DAPM_AIF_OUT_E("DMIC AIF", "Capture", 0,
  96                                SND_SOC_NOPM, 0, 0, dmic_aif_event,
  97                                SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
  98         SND_SOC_DAPM_INPUT("DMic"),
  99 };
 100
 101 static const struct snd_soc_dapm_route intercon[] = {
 102         {"DMIC AIF", NULL, "DMic"},
 103 };
 104
 105 static const struct snd_soc_component_driver soc_dmic = {
 106         .probe                  = dmic_component_probe,
 107         .dapm_widgets           = dmic_dapm_widgets,
 108         .num_dapm_widgets       = ARRAY_SIZE(dmic_dapm_widgets),
 109         .dapm_routes            = intercon,
 110         .num_dapm_routes        = ARRAY_SIZE(intercon),
 111         .idle_bias_on           = 1,
 112         .use_pmdown_time        = 1,
 113         .endianness             = 1,
 114         .non_legacy_dai_naming  = 1,
 115 };
 116
 117 static int dmic_dev_probe(struct platform_device *pdev)
 118 {
 119         int err;
 120         u32 chans;
 121         struct snd_soc_dai_driver *dai_drv = &dmic_dai;
 122
 123         if (pdev->dev.of_node) {
 124                 err = of_property_read_u32(pdev->dev.of_node, "num-channels", &chans);
 125                 if (err && (err != -EINVAL))
 126                         return err;
 127
 128                 if (!err) {
 129                         if (chans < 1 || chans > 8)
 130                                 return -EINVAL;
 131
 132                         dai_drv = devm_kzalloc(&pdev->dev, sizeof(*dai_drv), GFP_KERNEL);
 133                         if (!dai_drv)
 134                                 return -ENOMEM;
 135
 136                         memcpy(dai_drv, &dmic_dai, sizeof(*dai_drv));
 137                         dai_drv->capture.channels_max = chans;
 138                 }
 139         }
 140
 141         return devm_snd_soc_register_component(&pdev->dev,
 142                         &soc_dmic, dai_drv, 1);
 143 }
 144
 145 MODULE_ALIAS("platform:dmic-codec");
 146
 147 static const struct of_device_id dmic_dev_match[] = {
 148         {.compatible = "dmic-codec"},
 149         {}
 150 };
 151
 152 static struct platform_driver dmic_driver = {
 153         .driver = {
 154                 .name = "dmic-codec",
 155                 .of_match_table = dmic_dev_match,
 156         },
 157         .probe = dmic_dev_probe,
 158 };
 159
 160 module_platform_driver(dmic_driver);
 161
 162 MODULE_DESCRIPTION("Generic DMIC driver");
 163 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
 164 MODULE_LICENSE("GPL");