[alsa-devel] [RFC] ASoC: codecs: msm8916-wcd-analog: use btn0 released detection

[Srinivas Kandagatla]

On 13/09/17 21:43, Damien Riegel wrote:
> msm8916-wcd-analog uses button0 to differentiate between headphone and
> headset. Under some circumstances, button pressed and released
> interrupts are not fired as the driver expects it.
> 

This is what we need to understand to find a right solution,
I would like to understand on what is the difference in the hw layout.

To start with could you share the schematics/connections differences of 
this area on how the lines are wired up, I would like to compare it with

https://www.dropbox.com/s/zqqrqhd9d2yw7pr/Audio%C2%A0Mezzanine%C2%A0Board-SCH-0113.pdf?dl=0


thanks,
srini

> For instance, with some connectors, there are spurious button-pressed
> interrupts when unplugging a headphone, without the corresponding
> button-released interrupt. 
But the codec always alternates between
> button pressed and released interrupts, it cannot fire two interrupts of
> the same kind in a row. That means that when the headphone is plugged
> back, only a button-released interrupt will be fired instead of pressed
> then released. This causes the driver to report headphone as headset.
> 
> By changing the logic and relying on button 0 release interrupt, the
> driver could be made more robust for connectors that differ from the one
> used on the Dragonboard's audio mezzanine.
> 
> Signed-off-by: Damien Riegel <damien.riegel at savoirfairelinux.com>
> ---
>   sound/soc/codecs/msm8916-wcd-analog.c | 18 ++++++++----------
>   1 file changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/sound/soc/codecs/msm8916-wcd-analog.c b/sound/soc/codecs/msm8916-wcd-analog.c
> index 549c269acc7d..f562f2d86907 100644
> --- a/sound/soc/codecs/msm8916-wcd-analog.c
> +++ b/sound/soc/codecs/msm8916-wcd-analog.c
> @@ -285,7 +285,7 @@ struct pm8916_wcd_analog_priv {
>   	u16 codec_version;
>   	bool	mbhc_btn_enabled;
>   	/* special event to detect accessory type */
> -	bool	mbhc_btn0_pressed;
> +	int	mbhc_btn0_released;
>   	bool	detect_accessory_type;
>   	struct clk *mclk;
>   	struct snd_soc_codec *codec;
> @@ -483,7 +483,7 @@ static void pm8916_wcd_setup_mbhc(struct pm8916_wcd_analog_priv *wcd)
>   
>   	snd_soc_update_bits(codec, CDC_D_INT_EN_CLR, int_en_mask, 0);
>   	snd_soc_update_bits(codec, CDC_D_INT_EN_SET, int_en_mask, int_en_mask);
> -	wcd->mbhc_btn0_pressed = false;
> +	wcd->mbhc_btn0_released = false;
>   	wcd->detect_accessory_type = true;
>   }
>   
> @@ -950,7 +950,7 @@ static irqreturn_t mbhc_btn_release_irq_handler(int irq, void *arg)
>   
>   		/* check if its BTN0 thats released */
>   		if ((val != -1) && !(val & CDC_A_MBHC_RESULT_1_BTN_RESULT_MASK))
> -			priv->mbhc_btn0_pressed = false;
> +			priv->mbhc_btn0_released = true;
>   
>   	} else {
>   		snd_soc_jack_report(priv->jack, 0, btn_mask);
> @@ -983,9 +983,7 @@ static irqreturn_t mbhc_btn_press_irq_handler(int irq, void *arg)
>   		break;
>   	case 0x0:
>   		/* handle BTN_0 specially for type detection */
> -		if (priv->detect_accessory_type)
> -			priv->mbhc_btn0_pressed = true;
> -		else
> +		if (!priv->detect_accessory_type)
>   			snd_soc_jack_report(priv->jack,
>   					    SND_JACK_BTN_0, btn_mask);
>   		break;
> @@ -1029,19 +1027,19 @@ static irqreturn_t pm8916_mbhc_switch_irq_handler(int irq, void *arg)
>   		 * both press and release event received then its
>   		 * a headset.
>   		 */
> -		if (priv->mbhc_btn0_pressed)
> +		if (priv->mbhc_btn0_released)
>   			snd_soc_jack_report(priv->jack,
> -					    SND_JACK_HEADPHONE, hs_jack_mask);
> +					    SND_JACK_HEADSET, hs_jack_mask);
>   		else
>   			snd_soc_jack_report(priv->jack,
> -					    SND_JACK_HEADSET, hs_jack_mask);
> +					    SND_JACK_HEADPHONE, hs_jack_mask);
>   
>   		priv->detect_accessory_type = false;
>   
>   	} else { /* removal */
>   		snd_soc_jack_report(priv->jack, 0, hs_jack_mask);
>   		priv->detect_accessory_type = true;
> -		priv->mbhc_btn0_pressed = false;
> +		priv->mbhc_btn0_released = false;
>   	}
>   
>   	return IRQ_HANDLED;
>