The patch
ASoC: dmic: Add optional wakeup delay
has been applied to the asoc tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
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Thanks, Mark
From 05c9b302eda71083840392d74ce62dd1e1f30621 Mon Sep 17 00:00:00 2001
From: Matthias Kaehlcke mka@chromium.org Date: Fri, 16 Feb 2018 09:53:12 -0800 Subject: [PATCH] ASoC: dmic: Add optional wakeup delay
On some systems a delay is needed after switching on the clocks, to allow the output to stabilize and avoid a popping noise at the beginning of the recording. Add the optional device tree property 'wakeup-delay-ms' and apply the specified delay after enabling the mic. A blocking delay can't be applied in dmic_daiops_trigger() since the function is called in atomic context. Instead use a DAPM event handler to set the enable GPIO and apply the delay in the handler.
Signed-off-by: Matthias Kaehlcke mka@chromium.org Reviewed-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Mark Brown broonie@kernel.org --- Documentation/devicetree/bindings/sound/dmic.txt | 2 + sound/soc/codecs/dmic.c | 63 +++++++++++++----------- 2 files changed, 37 insertions(+), 28 deletions(-)
diff --git a/Documentation/devicetree/bindings/sound/dmic.txt b/Documentation/devicetree/bindings/sound/dmic.txt index f7bf65611453..e957b4136716 100644 --- a/Documentation/devicetree/bindings/sound/dmic.txt +++ b/Documentation/devicetree/bindings/sound/dmic.txt @@ -8,6 +8,7 @@ Required properties: Optional properties: - dmicen-gpios: GPIO specifier for dmic to control start and stop - num-channels: Number of microphones on this DAI + - wakeup-delay-ms: Delay (in ms) after enabling the DMIC
Example node:
@@ -15,4 +16,5 @@ Example node: compatible = "dmic-codec"; dmicen-gpios = <&gpio4 3 GPIO_ACTIVE_HIGH>; num-channels = <1>; + wakeup-delay-ms <50>; }; diff --git a/sound/soc/codecs/dmic.c b/sound/soc/codecs/dmic.c index 32a8f71d51f1..bac5bbb2dd59 100644 --- a/sound/soc/codecs/dmic.c +++ b/sound/soc/codecs/dmic.c @@ -19,6 +19,7 @@ * */
+#include <linux/delay.h> #include <linux/gpio.h> #include <linux/gpio/consumer.h> #include <linux/platform_device.h> @@ -29,34 +30,33 @@ #include <sound/soc.h> #include <sound/soc-dapm.h>
-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 { + struct gpio_desc *gpio_en; + int wakeup_delay; +};
- if (!dmic_en) - return 0; +static int dmic_aif_event(struct snd_soc_dapm_widget *w, + struct snd_kcontrol *kcontrol, int event) { + struct snd_soc_codec *codec = snd_soc_dapm_to_codec(w->dapm); + struct dmic *dmic = snd_soc_codec_get_drvdata(codec);
- switch (cmd) { - case SNDRV_PCM_TRIGGER_START: - case SNDRV_PCM_TRIGGER_RESUME: - case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: - gpiod_set_value(dmic_en, 1); + switch (event) { + case SND_SOC_DAPM_POST_PMU: + if (dmic->gpio_en) + gpiod_set_value(dmic->gpio_en, 1); + + if (dmic->wakeup_delay) + msleep(dmic->wakeup_delay); break; - case SNDRV_PCM_TRIGGER_STOP: - case SNDRV_PCM_TRIGGER_SUSPEND: - case SNDRV_PCM_TRIGGER_PAUSE_PUSH: - gpiod_set_value(dmic_en, 0); + case SND_SOC_DAPM_POST_PMD: + if (dmic->gpio_en) + gpiod_set_value(dmic->gpio_en, 0); break; }
return 0; }
-static const struct snd_soc_dai_ops dmic_dai_ops = { - .trigger = dmic_daiops_trigger, -}; - static struct snd_soc_dai_driver dmic_dai = { .name = "dmic-hifi", .capture = { @@ -68,26 +68,33 @@ static struct snd_soc_dai_driver dmic_dai = { | SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S16_LE, }, - .ops = &dmic_dai_ops, };
static int dmic_component_probe(struct snd_soc_component *component) { - struct gpio_desc *dmic_en; + struct dmic *dmic; + + dmic = devm_kzalloc(component->dev, sizeof(*dmic), GFP_KERNEL); + if (!dmic) + return -ENOMEM; + + dmic->gpio_en = devm_gpiod_get_optional(component->dev, + "dmicen", GPIOD_OUT_LOW); + if (IS_ERR(dmic->gpio_en)) + return PTR_ERR(dmic->gpio_en);
- dmic_en = devm_gpiod_get_optional(component->dev, - "dmicen", GPIOD_OUT_LOW); - if (IS_ERR(dmic_en)) - return PTR_ERR(dmic_en); + device_property_read_u32(component->dev, "wakeup-delay-ms", + &dmic->wakeup_delay);
- snd_soc_component_set_drvdata(component, dmic_en); + snd_soc_component_set_drvdata(component, dmic);
return 0; }
static const struct snd_soc_dapm_widget dmic_dapm_widgets[] = { - SND_SOC_DAPM_AIF_OUT("DMIC AIF", "Capture", 0, - SND_SOC_NOPM, 0, 0), + SND_SOC_DAPM_AIF_OUT_E("DMIC AIF", "Capture", 0, + SND_SOC_NOPM, 0, 0, dmic_aif_event, + SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD), SND_SOC_DAPM_INPUT("DMic"), };