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ASoC: max98357a: avoid speaker pop when playback startup

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Loud speaker pop happens during playback even when in slience
playback. Specify Max98357a amp delay times to make sure
clocks are always earlier than sdmode on.

Signed-off-by: Mac Chiang <mac.chiang@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Mac Chiang 2019-06-19 18:18:33 +08:00 committed by Mark Brown
parent 4b9b73b865
commit cec5b01f8f
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GPG Key ID: 24D68B725D5487D0
2 changed files with 50 additions and 9 deletions
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4
Documentation/devicetree/bindings/sound/max98357a.txt
View File

@ -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:

55
sound/soc/codecs/max98357a.c
View File

@ -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,