+ Brian & Dylan
El Thu, Jan 04, 2018 at 11:48:48AM -0800 Matthias Kaehlcke ha dit:
The DMIC DAI driver specifies a number of 1 to 8 channels for each DAI. The actual number of mics can currently not be configured in the device tree or audio glue, but is derived from the min/max channels of the CPU and codec DAI. A typical CPU DAI has two or more channels, in consequence a single mic is treated as a stereo/multi channel device, even though only one channel carries audio data.
This change adds the option to specify the number of used DMIC channels in the device tree. If a single channel is used we export a channel map that marks all unused channels as invalid to indicate userspace that the capture device is mono.
Signed-off-by: Matthias Kaehlcke mka@chromium.org
Documentation/devicetree/bindings/sound/dmic.txt | 2 + sound/soc/codecs/dmic.c | 72 +++++++++++++++++++++--- 2 files changed, 65 insertions(+), 9 deletions(-)
diff --git a/Documentation/devicetree/bindings/sound/dmic.txt b/Documentation/devicetree/bindings/sound/dmic.txt index 54c8ef6498a8..f7bf65611453 100644 --- a/Documentation/devicetree/bindings/sound/dmic.txt +++ b/Documentation/devicetree/bindings/sound/dmic.txt @@ -7,10 +7,12 @@ Required properties:
Optional properties:
- dmicen-gpios: GPIO specifier for dmic to control start and stop
- num-channels: Number of microphones on this DAI
Example node:
dmic_codec: dmic@0 { compatible = "dmic-codec"; dmicen-gpios = <&gpio4 3 GPIO_ACTIVE_HIGH>;
num-channels = <1>;diff --git a/sound/soc/codecs/dmic.c b/sound/soc/codecs/dmic.c index b88a1ee66f80..c705a25b138e 100644 --- a/sound/soc/codecs/dmic.c +++ b/sound/soc/codecs/dmic.c @@ -29,24 +29,29 @@ #include <sound/soc.h> #include <sound/soc-dapm.h>
+struct dmic {
- struct gpio_desc *gpio_en;
- int channels;
+};
static int dmic_daiops_trigger(struct snd_pcm_substream *substream, int cmd, struct snd_soc_dai *dai) {
- struct gpio_desc *dmic_en = snd_soc_dai_get_drvdata(dai);
- struct dmic *dmic = snd_soc_dai_get_drvdata(dai);
- if (!dmic_en)
if (!dmic || !dmic->gpio_en) return 0;
switch (cmd) { case SNDRV_PCM_TRIGGER_START: case SNDRV_PCM_TRIGGER_RESUME: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
gpiod_set_value(dmic_en, 1);
gpiod_set_value(dmic->gpio_en, 1);
gpiod_set_value(dmic_en, 0);
gpiod_set_value(dmic->gpio_en, 0);@@ -57,6 +62,42 @@ static const struct snd_soc_dai_ops dmic_dai_ops = { .trigger = dmic_daiops_trigger, };
+const struct snd_pcm_chmap_elem dmic_chmaps_single[] = {
- { .channels = 1,
.map = { SNDRV_CHMAP_MONO } },- { .channels = 2,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_NA } },- { .channels = 4,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_NA,SNDRV_CHMAP_NA, SNDRV_CHMAP_NA } },- { .channels = 6,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_NA,SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,SNDRV_CHMAP_NA, SNDRV_CHMAP_NA } },- { .channels = 8,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_NA,SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,SNDRV_CHMAP_NA, SNDRV_CHMAP_NA } },- { }
+};
+static int dmic_pcm_new(struct snd_soc_pcm_runtime *rtd,
struct snd_soc_dai *dai)+{
- struct dmic *dmic = snd_soc_dai_get_drvdata(dai);
- int err;
- if (dmic->channels == 1) {
err = snd_pcm_add_chmap_ctls(rtd->pcm, SNDRV_PCM_STREAM_CAPTURE,dmic_chmaps_single, 8, 0, NULL);if (err < 0)return err;- }
- return 0;
+}
static struct snd_soc_dai_driver dmic_dai = { .name = "dmic-hifi", .capture = { @@ -69,18 +110,31 @@ static struct snd_soc_dai_driver dmic_dai = { | SNDRV_PCM_FMTBIT_S16_LE, }, .ops = &dmic_dai_ops,
- .pcm_new = dmic_pcm_new,
};
static int dmic_codec_probe(struct snd_soc_codec *codec) {
- struct gpio_desc *dmic_en;
- struct dmic *dmic;
- int err;
- u32 pval;
- dmic = devm_kzalloc(codec->dev, sizeof(*dmic), GFP_KERNEL);
- if (!dmic)
return -ENOMEM;
- dmic_en = devm_gpiod_get_optional(codec->dev,
- dmic->gpio_en = devm_gpiod_get_optional(codec->dev, "dmicen", GPIOD_OUT_LOW);
- if (IS_ERR(dmic_en))
return PTR_ERR(dmic_en);
- if (IS_ERR(dmic->gpio_en))
return PTR_ERR(dmic->gpio_en);- err = of_property_read_u32(codec->dev->of_node, "num-channels", &pval);
- if (!err)
dmic->channels = (int)pval;- else if (err != -ENOENT)
return err;
- snd_soc_codec_set_drvdata(codec, dmic_en);
snd_soc_codec_set_drvdata(codec, dmic);
return 0;
}