Hi Mark,
Unfortunately, this was not the case with my tests. The supply is switched off at the start of the driver, but when starting a recording not started. The function "mic_bias_event" only consumes SND_SOC_DAPM_POST_PMU (0x02) and SND_SOC_DAPM_PRE_PMD (0x04).
I changed:
SND_SOC_DAPM_SUPPLY("Mic Bias", SGTL5000_CHIP_MIC_CTRL, 8, 0, mic_bias_event, SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
to:
SND_SOC_DAPM_SUPPLY("Mic Bias", SGTL5000_CHIP_MIC_CTRL, 8, 0, mic_bias_event, 0xFF),
To receive all events.
And added this to "mic_bias_event":
dev_info(codec->dev, "mic_bias_event event: %d\n", event);
At probing I got this: sgtl5000 1-000a: mic_bias_event event: 128 sgtl5000 1-000a: mic_bias_event event: 4 --> /* before widget power down, this disables the mic-bias-resistor */ sgtl5000 1-000a: mic_bias_event event: 8 --> /* after widget power down */
Testing: arecord -D "hw:0,1" -c 2 -f S16_LE -t wav test_recording.wav Recording WAVE 'test_recording.wav' : Signed 16 bit Little Endian, Rate 8000 Hz, Stereo ==> no event was fired
With my patch included, at probing: sgtl5000 1-000a: mic_bias_event event: 128 sgtl5000 1-000a: mic_bias_event event: 4 --> /* before widget power down, this disables the mic-bias-resistor */ sgtl5000 1-000a: mic_bias_event event: 8 --> /* after widget power down */
Testing: arecord -D "hw:0,1" -c 2 -f S16_LE -t wav test_recording.wav Recording WAVE 'test_recording.wav' : Signed 16 bit Little Endian, Rate 8000 Hz, Stereo [ 82.341376] sgtl5000 1-000a: mic_bias_event event: 1 --> /* before widget power up */ [ 82.762701] sgtl5000 1-000a: mic_bias_event event: 2 --> /* after widget power up, this enables the supply */ ^CAborted by signal Interrupt... [ 90.362685] sgtl5000 1-000a: mic_bias_event event: 4 --> /* before widget power down, this disables the mic-bias-resistor */ [ 90.369561] sgtl5000 1-000a: mic_bias_event event: 8 --> /* after widget power down */ ==> events are working
The disadvantage is that this is also done when playing audio: aplay -D "hw:0,0" -c 2 -f S16_LE -t wav test_recording.wav sgtl5000 1-000a: mic_bias_event event: 1 sgtl5000 1-000a: mic_bias_event event: 2 Playing WAVE 'test_recording.wav' : Signed 16 bit Little Endian, Rate 8000 Hz, Stereo sgtl5000 1-000a: mic_bias_event event: 4 sgtl5000 1-000a: mic_bias_event event: 8
I'm not so into ALSA, maybe there is another way to set the event properly.
Kind regards, Christian
-----Ursprüngliche Nachricht----- Von: Mark Brown [mailto:broonie@kernel.org] Gesendet: Donnerstag, 11. Januar 2018 16:07 An: Fischer, Christian fischerc@swissphone.de Cc: alsa-devel@alsa-project.org; lgirdwood@gmail.com; perex@perex.cz; tiwai@suse.com; richard.leitner@skidata.com; fabio.estevam@nxp.com; bhumirks@gmail.com; linux-kernel@vger.kernel.org Betreff: Re: [PATCH] ASoC: sgtl5000: fix powerup/down of micbias-voltage
On Thu, Jan 11, 2018 at 09:40:31AM +0100, fischerc@swissphone.de wrote:
The mic-bias-voltage should get powered up/down automatically. Added missing DAPM_PRE and DAPM_POST widgets to fire up the mic_bias_event function.
- SND_SOC_DAPM_PRE("MIC_BIAS_PRE", mic_bias_event),
- SND_SOC_DAPM_POST("MIC_BIAS_POST", mic_bias_event),
I don't understand what this is intended to do. The mic_bias_event() callback is already hooked up to the Mic Bias supply widget, it should be invoked whenever the bias is turned on and off already?