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-rw-r--r--Documentation/devicetree/bindings/sound/max98357a.txt4
-rw-r--r--sound/soc/codecs/max98357a.c55
2 files changed, 50 insertions, 9 deletions
diff --git a/Documentation/devicetree/bindings/sound/max98357a.txt b/Documentation/devicetree/bindings/sound/max98357a.txt
index 28645a2ff885..4bce14ce806f 100644
--- a/Documentation/devicetree/bindings/sound/max98357a.txt
+++ b/Documentation/devicetree/bindings/sound/max98357a.txt
@@ -9,6 +9,10 @@ Optional properties:
- sdmode-gpios : GPIO specifier for the chip's SD_MODE pin.
If this option is not specified then driver does not manage
the pin state (e.g. chip is always on).
+- sdmode-delay : specify delay time for SD_MODE pin.
+ If this option is specified, which means it's required i2s clocks
+ ready before SD_MODE is unmuted in order to avoid the speaker pop noise.
+ It's observed that 5ms is sufficient.
Example:
diff --git a/sound/soc/codecs/max98357a.c b/sound/soc/codecs/max98357a.c
index 6f724c9a3867..6f0e28f903bf 100644
--- a/sound/soc/codecs/max98357a.c
+++ b/sound/soc/codecs/max98357a.c
@@ -19,24 +19,42 @@
#include <sound/soc-dai.h>
#include <sound/soc-dapm.h>
+struct max98357a_priv {
+ struct delayed_work enable_sdmode_work;
+ struct gpio_desc *sdmode;
+ unsigned int sdmode_delay;
+};
+
+static void max98357a_enable_sdmode_work(struct work_struct *work)
+{
+ struct max98357a_priv *max98357a =
+ container_of(work, struct max98357a_priv,
+ enable_sdmode_work.work);
+
+ gpiod_set_value(max98357a->sdmode, 1);
+}
+
static int max98357a_daiops_trigger(struct snd_pcm_substream *substream,
int cmd, struct snd_soc_dai *dai)
{
- struct gpio_desc *sdmode = snd_soc_dai_get_drvdata(dai);
+ struct max98357a_priv *max98357a = snd_soc_dai_get_drvdata(dai);
- if (!sdmode)
+ if (!max98357a->sdmode)
return 0;
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
- gpiod_set_value(sdmode, 1);
+ queue_delayed_work(system_power_efficient_wq,
+ &max98357a->enable_sdmode_work,
+ msecs_to_jiffies(max98357a->sdmode_delay));
break;
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
- gpiod_set_value(sdmode, 0);
+ cancel_delayed_work_sync(&max98357a->enable_sdmode_work);
+ gpiod_set_value(max98357a->sdmode, 0);
break;
}
@@ -90,14 +108,33 @@ static struct snd_soc_dai_driver max98357a_dai_driver = {
static int max98357a_platform_probe(struct platform_device *pdev)
{
- struct gpio_desc *sdmode;
+ struct max98357a_priv *max98357a;
+ int ret;
- sdmode = devm_gpiod_get_optional(&pdev->dev,
+ max98357a = devm_kzalloc(&pdev->dev, sizeof(*max98357a), GFP_KERNEL);
+
+ if (!max98357a)
+ return -ENOMEM;
+
+ max98357a->sdmode = devm_gpiod_get_optional(&pdev->dev,
"sdmode", GPIOD_OUT_LOW);
- if (IS_ERR(sdmode))
- return PTR_ERR(sdmode);
- dev_set_drvdata(&pdev->dev, sdmode);
+ if (IS_ERR(max98357a->sdmode))
+ return PTR_ERR(max98357a->sdmode);
+
+ ret = device_property_read_u32(&pdev->dev, "sdmode-delay",
+ &max98357a->sdmode_delay);
+
+ if (ret) {
+ max98357a->sdmode_delay = 0;
+ dev_dbg(&pdev->dev,
+ "no optional property 'sdmode-delay' found, default: no delay\n");
+ }
+
+ dev_set_drvdata(&pdev->dev, max98357a);
+
+ INIT_DELAYED_WORK(&max98357a->enable_sdmode_work,
+ max98357a_enable_sdmode_work);
return devm_snd_soc_register_component(&pdev->dev,
&max98357a_component_driver,