asoc: codecs: Add comparator autozeroing support for rouleur

When current source mode is enabled, comparator auto
zeroing should be turned ON by HW. As rouleur codec HW
doesn't do this automatically, add this support
in SW to set the auto zero enable before FSM enable
and reset to auto once FSM is enabled.
Disable surge protection before ADC measurements
and change HPHL and HPHR thresholds while
identifying cross connection for proper
accessory identification.

Change-Id: Ib775de0f0bdb6c655a3c0eb4775276acfbca1e84
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>

asoc/codecs/wcd-mbhc-adc.c

@@ -80,8 +80,22 @@ static int wcd_measure_adc_continuous(struct wcd_mbhc *mbhc)
 	WCD_MBHC_REG_UPDATE_BITS(WCD_MBHC_FSM_EN, 0);
 	/* Set the MUX selection to IN2P */
 	WCD_MBHC_REG_UPDATE_BITS(WCD_MBHC_MUX_CTL, MUX_CTL_IN2P);
+
+	/*
+	 * Current source mode requires Auto zeroing to be enabled
+	 * automatically. If HW doesn't do it, SW has to take care of this
+	 * for button interrupts to work fine and to avoid
+	 * fake electrical removal interrupts by enabling autozero before FSM
+	 * enable and disable it after FSM enable
+	 */
+	if (mbhc->mbhc_cb->mbhc_comp_autozero_control)
+		mbhc->mbhc_cb->mbhc_comp_autozero_control(mbhc,
+							true);
 	/* Enable MBHC FSM */
 	WCD_MBHC_REG_UPDATE_BITS(WCD_MBHC_FSM_EN, 1);
+	if (mbhc->mbhc_cb->mbhc_comp_autozero_control)
+		mbhc->mbhc_cb->mbhc_comp_autozero_control(mbhc,
+							false);
 	/* Enable ADC_ENABLE bit */
 	WCD_MBHC_REG_UPDATE_BITS(WCD_MBHC_ADC_EN, 1);
 
@@ -294,6 +308,10 @@ static int wcd_check_cross_conn(struct wcd_mbhc *mbhc)
 	WCD_MBHC_REG_READ(WCD_MBHC_ELECT_SCHMT_ISRC, elect_ctl);
 	WCD_MBHC_REG_UPDATE_BITS(WCD_MBHC_ELECT_SCHMT_ISRC, 0x00);
 
+	/* Disable surge detection before ADC measurement */
+	if (mbhc->mbhc_cb->mbhc_surge_ctl)
+		mbhc->mbhc_cb->mbhc_surge_ctl(mbhc, false);
+
 	/* Read and set ADC to single measurement */
 	WCD_MBHC_REG_READ(WCD_MBHC_ADC_MODE, adc_mode);
 	/* Read ADC Enable bit to restore after adc measurement */
@@ -317,7 +335,12 @@ static int wcd_check_cross_conn(struct wcd_mbhc *mbhc)
 		goto done;
 	}
 
-	if (hphl_adc_res > 100 || hphr_adc_res > 100) {
+	/* Update cross connection threshold voltages if needed */
+	if (mbhc->mbhc_cb->update_cross_conn_thr)
+		mbhc->mbhc_cb->update_cross_conn_thr(mbhc);
+
+	if (hphl_adc_res > mbhc->hphl_cross_conn_thr ||
+	    hphr_adc_res > mbhc->hphr_cross_conn_thr) {
 		plug_type = MBHC_PLUG_TYPE_GND_MIC_SWAP;
 		pr_debug("%s: Cross connection identified\n", __func__);
 	} else {
@@ -339,6 +362,10 @@ done:
 	/* Restore FSM state */
 	WCD_MBHC_REG_UPDATE_BITS(WCD_MBHC_FSM_EN, fsm_en);
 
+	/* Restore surge detection */
+	if (mbhc->mbhc_cb->mbhc_surge_ctl)
+		mbhc->mbhc_cb->mbhc_surge_ctl(mbhc, true);
+
 	/* Restore electrical detection */
 	WCD_MBHC_REG_UPDATE_BITS(WCD_MBHC_ELECT_SCHMT_ISRC, elect_ctl);