[PATCH v2] ASoC: codecs: MBHC: Add support for special headset

[Stephen Boyd]

Quoting Srinivasa Rao Mandadapu (2021-11-14 23:11:28)
> diff --git a/sound/soc/codecs/wcd-mbhc-v2.c b/sound/soc/codecs/wcd-mbhc-v2.c
> index 405128c..d6545e4 100644
> --- a/sound/soc/codecs/wcd-mbhc-v2.c
> +++ b/sound/soc/codecs/wcd-mbhc-v2.c
> @@ -1022,6 +1022,56 @@ static int wcd_mbhc_get_plug_from_adc(struct wcd_mbhc *mbhc, int adc_result)
>         return plug_type;
>  }
>
> +static int wcd_mbhc_get_spl_hs_thres(struct wcd_mbhc *mbhc)
> +{
> +       int hs_threshold, micbias_mv;
> +
> +       micbias_mv = wcd_mbhc_get_micbias(mbhc);
> +       if (mbhc->cfg->hs_thr && mbhc->cfg->micb_mv != WCD_MBHC_ADC_MICBIAS_MV) {
> +               if (mbhc->cfg->micb_mv == micbias_mv)
> +                       hs_threshold = mbhc->cfg->hs_thr;
> +               else
> +                       hs_threshold = (mbhc->cfg->hs_thr * micbias_mv) / mbhc->cfg->micb_mv;
> +       } else {
> +               hs_threshold = ((WCD_MBHC_ADC_HS_THRESHOLD_MV * micbias_mv) /
> +                                                       WCD_MBHC_ADC_MICBIAS_MV);
> +       }
> +       return hs_threshold;
> +}
> +
> +static bool wcd_mbhc_check_for_spl_headset(struct wcd_mbhc *mbhc)
> +{
> +       bool is_spl_hs = false;
> +       int output_mv, hs_threshold, hph_threshold;
> +
> +       if (!mbhc->mbhc_cb->mbhc_micb_ctrl_thr_mic)
> +               return false;
> +
> +       /* Bump up MIC_BIAS2 to 2.7V */
> +       mbhc->mbhc_cb->mbhc_micb_ctrl_thr_mic(mbhc->component, MIC_BIAS_2, true);
> +       usleep_range(10000, 10100);
> +
> +       output_mv = wcd_measure_adc_once(mbhc, MUX_CTL_IN2P);
> +       hs_threshold = wcd_mbhc_get_spl_hs_thres(mbhc);
> +       hph_threshold = wcd_mbhc_adc_get_hph_thres(mbhc);
> +
> +       if (output_mv > hs_threshold || output_mv < hph_threshold) {
> +               if (mbhc->force_linein == true)

Just 'if (mbhc->force_linein)'

Also, if this is false, then false is set above. So checking for
mbhc->force_linein is useless.

> +                       is_spl_hs = false;
> +       } else {
> +               is_spl_hs = true;
> +       }
> +
> +       /* Back MIC_BIAS2 to 1.8v if the type is not special headset */
> +       if (!is_spl_hs) {
> +               mbhc->mbhc_cb->mbhc_micb_ctrl_thr_mic(mbhc->component, MIC_BIAS_2, false);
> +               /* Add 10ms delay for micbias to settle */
> +               usleep_range(10000, 10100);
> +       }
> +
> +       return is_spl_hs;
> +}
> +
>  static void wcd_correct_swch_plug(struct work_struct *work)
>  {
>         struct wcd_mbhc *mbhc;
> @@ -1029,12 +1079,14 @@ static void wcd_correct_swch_plug(struct work_struct *work)
>         enum wcd_mbhc_plug_type plug_type = MBHC_PLUG_TYPE_INVALID;
>         unsigned long timeout;
>         int pt_gnd_mic_swap_cnt = 0;
> -       int output_mv, cross_conn, hs_threshold, try = 0;
> +       int output_mv, cross_conn, hs_threshold, try = 0, micbias_mv;
> +       bool is_spl_hs = false;
>         bool is_pa_on;
>
>         mbhc = container_of(work, struct wcd_mbhc, correct_plug_swch);
>         component = mbhc->component;
>
> +       micbias_mv = wcd_mbhc_get_micbias(mbhc);
>         hs_threshold = wcd_mbhc_adc_get_hs_thres(mbhc);
>
>         /* Mask ADC COMPLETE interrupt */
> @@ -1097,6 +1149,16 @@ static void wcd_correct_swch_plug(struct work_struct *work)
>                 plug_type = wcd_mbhc_get_plug_from_adc(mbhc, output_mv);
>                 is_pa_on = wcd_mbhc_read_field(mbhc, WCD_MBHC_HPH_PA_EN);
>
> +               if ((output_mv > hs_threshold) && (!is_spl_hs)) {

Please drop useless parenthesis

> +                       is_spl_hs = wcd_mbhc_check_for_spl_headset(mbhc);
> +                       output_mv = wcd_measure_adc_once(mbhc, MUX_CTL_IN2P);
> +
> +                       if (is_spl_hs) {
> +                               hs_threshold = (hs_threshold * wcd_mbhc_get_micbias(mbhc)) /
> +                                                                       micbias_mv;

Same. It may be good to split it to two assignments to clarify
overflow/underflow.

> +                       }
> +               }
> +
>                 if ((output_mv <= hs_threshold) && !is_pa_on) {
>                         /* Check for cross connection*/
>                         cross_conn = wcd_check_cross_conn(mbhc);
> @@ -1122,14 +1184,19 @@ static void wcd_correct_swch_plug(struct work_struct *work)
>                         }
>                 }
>
> -               if (output_mv > hs_threshold) /* cable is extension cable */
> +               /* cable is extension cable */
> +               if (output_mv > hs_threshold || mbhc->force_linein == true)

Drop the == true please.

>                         plug_type = MBHC_PLUG_TYPE_HIGH_HPH;
>         }
>
>         wcd_mbhc_bcs_enable(mbhc, plug_type, true);
>
> -       if (plug_type == MBHC_PLUG_TYPE_HIGH_HPH)
> -               wcd_mbhc_write_field(mbhc, WCD_MBHC_ELECT_ISRC_EN, 1);
> +       if (plug_type == MBHC_PLUG_TYPE_HIGH_HPH) {
> +               if (is_spl_hs)
> +                       plug_type = MBHC_PLUG_TYPE_HEADSET;
> +               else
> +                       wcd_mbhc_write_field(mbhc, WCD_MBHC_ELECT_ISRC_EN, 1);
> +       }
>
>         wcd_mbhc_write_field(mbhc, WCD_MBHC_ADC_MODE, 0);
>         wcd_mbhc_write_field(mbhc, WCD_MBHC_ADC_EN, 0);