diff mbox

ASoC: codecs: dmic: Make number of channels configurable

Message ID 20180105203957.184883-1-mka@chromium.org (mailing list archive)
State Accepted
Commit 7fb59e940f6225beed0b24cd09e9fad9aebb7565
Headers show

Commit Message

Matthias Kaehlcke Jan. 5, 2018, 8:39 p.m. UTC
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. When specified this value overwrites the default
channels_max value of 8 in the snd_soc_dai_driver struct of the codec.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
 Documentation/devicetree/bindings/sound/dmic.txt |  2 ++
 sound/soc/codecs/dmic.c                          | 24 +++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

Comments

Rob Herring (Arm) Jan. 9, 2018, 4:17 a.m. UTC | #1
On Fri, Jan 05, 2018 at 12:39:57PM -0800, Matthias Kaehlcke wrote:
> 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. When specified this value overwrites the default
> channels_max value of 8 in the snd_soc_dai_driver struct of the codec.
> 
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
>  Documentation/devicetree/bindings/sound/dmic.txt |  2 ++

Reviewed-by: Rob Herring <robh@kernel.org>

>  sound/soc/codecs/dmic.c                          | 24 +++++++++++++++++++++++-
>  2 files changed, 25 insertions(+), 1 deletion(-)
Arnaud POULIQUEN Jan. 9, 2018, 9:04 a.m. UTC | #2
Hello Mathias,

Next time could you add patch version in your mail subject ( [PATCH vX])
easier to follow versions :-).

otherwise,

Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>

Regards,
Arnaud

On 01/05/2018 09:39 PM, Matthias Kaehlcke wrote:
> 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. When specified this value overwrites the default
> channels_max value of 8 in the snd_soc_dai_driver struct of the codec.
> 
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
>  Documentation/devicetree/bindings/sound/dmic.txt |  2 ++
>  sound/soc/codecs/dmic.c                          | 24
> +++++++++++++++++++++++-
>  2 files changed, 25 insertions(+), 1 deletion(-)
> 
> 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..c88f974ebe3e 100644
> --- a/sound/soc/codecs/dmic.c
> +++ b/sound/soc/codecs/dmic.c
> @@ -107,8 +107,30 @@ static const struct snd_soc_codec_driver soc_dmic = {
>  
>  static int dmic_dev_probe(struct platform_device *pdev)
>  {
> +       int err;
> +       u32 chans;
> +       struct snd_soc_dai_driver *dai_drv = &dmic_dai;
> +
> +       if (pdev->dev.of_node) {
> +               err = of_property_read_u32(pdev->dev.of_node,
> "num-channels", &chans);
> +               if (err && (err != -ENOENT))
> +                       return err;
> +
> +               if (!err) {
> +                       if (chans < 1 || chans > 8)
> +                               return -EINVAL;
> +
> +                       dai_drv = devm_kzalloc(&pdev->dev,
> sizeof(*dai_drv), GFP_KERNEL);
> +                       if (!dai_drv)
> +                               return -ENOMEM;
> +
> +                       memcpy(dai_drv, &dmic_dai, sizeof(*dai_drv));
> +                       dai_drv->capture.channels_max = chans;
> +               }
> +       }
> +

>          return snd_soc_register_codec(&pdev->dev,
> -                       &soc_dmic, &dmic_dai, 1);
> +                       &soc_dmic, dai_drv, 1);
>  }
>  
>  static int dmic_dev_remove(struct platform_device *pdev)
> -- 
> 2.16.0.rc0.223.g4a4ac83678-goog
>
diff mbox

Patch

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..c88f974ebe3e 100644
--- a/sound/soc/codecs/dmic.c
+++ b/sound/soc/codecs/dmic.c
@@ -107,8 +107,30 @@  static const struct snd_soc_codec_driver soc_dmic = {
 
 static int dmic_dev_probe(struct platform_device *pdev)
 {
+	int err;
+	u32 chans;
+	struct snd_soc_dai_driver *dai_drv = &dmic_dai;
+
+	if (pdev->dev.of_node) {
+		err = of_property_read_u32(pdev->dev.of_node, "num-channels", &chans);
+		if (err && (err != -ENOENT))
+			return err;
+
+		if (!err) {
+			if (chans < 1 || chans > 8)
+				return -EINVAL;
+
+			dai_drv = devm_kzalloc(&pdev->dev, sizeof(*dai_drv), GFP_KERNEL);
+			if (!dai_drv)
+				return -ENOMEM;
+
+			memcpy(dai_drv, &dmic_dai, sizeof(*dai_drv));
+			dai_drv->capture.channels_max = chans;
+		}
+	}
+
 	return snd_soc_register_codec(&pdev->dev,
-			&soc_dmic, &dmic_dai, 1);
+			&soc_dmic, dai_drv, 1);
 }
 
 static int dmic_dev_remove(struct platform_device *pdev)