qpnp-smb2: fix reverse boost when input is removed

When any input is removed it is likely that reverse boost can happen.
Detect reverse boost by checking if the switcher-power-ok interrupt
triggers 3 times within 1 second. If detected then suspend all input.
Once VBUS falls the input can be resumed for the next insertion.

Change-Id: I3dbe4fe426111023b60eefd968c426be7d6057b9
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>

3 files changed, 56 insertions, 10 deletions

diff --git a/drivers/power/qcom-charger/qpnp-smb2.c b/drivers/power/qcom-charger/qpnp-smb2.c
index f9d76c56aa2e..0e2f5afb9416 100644
--- a/drivers/power/qcom-charger/qpnp-smb2.c
+++ b/drivers/power/qcom-charger/qpnp-smb2.c
@@ -1241,6 +1241,7 @@ static int smb2_setup_wa_flags(struct smb2 *chip)
 
 	switch (pmic_rev_id->pmic_subtype) {
 	case PMICOBALT_SUBTYPE:
+		chip->chg.wa_flags |= BOOST_BACK_WA;
 		if (pmic_rev_id->rev4 == PMICOBALT_V1P1_REV4) /* PMI rev 1.1 */
 			chg->wa_flags |= QC_CHARGER_DETECTION_WA_BIT;
 		break;
@@ -1451,7 +1452,8 @@ static struct smb2_irq_info smb2_irqs[] = {
 	},
 	{
 		.name		= "switcher-power-ok",
-		.handler	= smblib_handle_debug,
+		.handler	= smblib_handle_switcher_power_ok,
+		.storm_data	= {true, 1000, 3},
 	},
 };
 
diff --git a/drivers/power/qcom-charger/smb-lib.c b/drivers/power/qcom-charger/smb-lib.c
index 198e77469bbe..7a542c59f496 100644
--- a/drivers/power/qcom-charger/smb-lib.c
+++ b/drivers/power/qcom-charger/smb-lib.c
@@ -596,7 +596,11 @@ static int smblib_usb_suspend_vote_callback(struct votable *votable, void *data,
 {
 	struct smb_charger *chg = data;
 
-	return smblib_set_usb_suspend(chg, suspend);
+	/* resume input if suspend is invalid */
+	if (suspend < 0)
+		suspend = 0;
+
+	return smblib_set_usb_suspend(chg, (bool)suspend);
 }
 
 static int smblib_dc_suspend_vote_callback(struct votable *votable, void *data,
@@ -604,10 +608,11 @@ static int smblib_dc_suspend_vote_callback(struct votable *votable, void *data,
 {
 	struct smb_charger *chg = data;
 
+	/* resume input if suspend is invalid */
 	if (suspend < 0)
-		suspend = false;
+		suspend = 0;
 
-	return smblib_set_dc_suspend(chg, suspend);
+	return smblib_set_dc_suspend(chg, (bool)suspend);
 }
 
 static int smblib_fcc_max_vote_callback(struct votable *votable, void *data,
@@ -2230,11 +2235,8 @@ irqreturn_t smblib_handle_usb_plugin(int irq, void *data)
 		}
 	}
 
-	if (!chg->dpdm_reg)
-		goto skip_dpdm_float;
-
 	if (chg->vbus_present) {
-		if (!regulator_is_enabled(chg->dpdm_reg)) {
+		if (chg->dpdm_reg && !regulator_is_enabled(chg->dpdm_reg)) {
 			smblib_dbg(chg, PR_MISC, "enabling DPDM regulator\n");
 			rc = regulator_enable(chg->dpdm_reg);
 			if (rc < 0)
@@ -2242,7 +2244,14 @@ irqreturn_t smblib_handle_usb_plugin(int irq, void *data)
 					rc);
 		}
 	} else {
-		if (regulator_is_enabled(chg->dpdm_reg)) {
+		if (chg->wa_flags & BOOST_BACK_WA) {
+			vote(chg->usb_suspend_votable,
+						BOOST_BACK_VOTER, false, 0);
+			vote(chg->dc_suspend_votable,
+						BOOST_BACK_VOTER, false, 0);
+		}
+
+		if (chg->dpdm_reg && regulator_is_enabled(chg->dpdm_reg)) {
 			smblib_dbg(chg, PR_MISC, "disabling DPDM regulator\n");
 			rc = regulator_disable(chg->dpdm_reg);
 			if (rc < 0)
@@ -2251,7 +2260,6 @@ irqreturn_t smblib_handle_usb_plugin(int irq, void *data)
 		}
 	}
 
-skip_dpdm_float:
 	power_supply_changed(chg->usb_psy);
 	smblib_dbg(chg, PR_INTERRUPT, "IRQ: %s %s\n",
 		   irq_data->name, chg->vbus_present ? "attached" : "detached");
@@ -2683,6 +2691,39 @@ irqreturn_t smblib_handle_high_duty_cycle(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+irqreturn_t smblib_handle_switcher_power_ok(int irq, void *data)
+{
+	struct smb_irq_data *irq_data = data;
+	struct smb_charger *chg = irq_data->parent_data;
+	int rc;
+	u8 stat;
+
+	if (!(chg->wa_flags & BOOST_BACK_WA))
+		return IRQ_HANDLED;
+
+	rc = smblib_read(chg, POWER_PATH_STATUS_REG, &stat);
+	if (rc < 0) {
+		smblib_err(chg, "Couldn't read POWER_PATH_STATUS rc=%d\n", rc);
+		return IRQ_HANDLED;
+	}
+
+	if ((stat & USE_USBIN_BIT) &&
+				get_effective_result(chg->usb_suspend_votable))
+		return IRQ_HANDLED;
+
+	if ((stat & USE_DCIN_BIT) &&
+				get_effective_result(chg->dc_suspend_votable))
+		return IRQ_HANDLED;
+
+	if (is_storming(&irq_data->storm_data)) {
+		smblib_dbg(chg, PR_MISC, "reverse boost detected; suspending input\n");
+		vote(chg->usb_suspend_votable, BOOST_BACK_VOTER, true, 0);
+		vote(chg->dc_suspend_votable, BOOST_BACK_VOTER, true, 0);
+	}
+
+	return IRQ_HANDLED;
+}
+
 /***************
  * Work Queues *
  ***************/
diff --git a/drivers/power/qcom-charger/smb-lib.h b/drivers/power/qcom-charger/smb-lib.h
index 4be06ffcfb25..61168f7f71e6 100644
--- a/drivers/power/qcom-charger/smb-lib.h
+++ b/drivers/power/qcom-charger/smb-lib.h
@@ -46,6 +46,7 @@ enum print_reason {
 #define VBUS_CC_SHORT_VOTER		"VBUS_CC_SHORT_VOTER"
 #define LEGACY_CABLE_VOTER		"LEGACY_CABLE_VOTER"
 #define PD_INACTIVE_VOTER		"PD_INACTIVE_VOTER"
+#define BOOST_BACK_VOTER		"BOOST_BACK_VOTER"
 
 enum smb_mode {
 	PARALLEL_MASTER = 0,
@@ -55,6 +56,7 @@ enum smb_mode {
 
 enum {
 	QC_CHARGER_DETECTION_WA_BIT = BIT(0),
+	BOOST_BACK_WA = BIT(1),
 };
 
 struct smb_regulator {
@@ -240,6 +242,7 @@ irqreturn_t smblib_handle_icl_change(int irq, void *data);
 irqreturn_t smblib_handle_usb_typec_change(int irq, void *data);
 irqreturn_t smblib_handle_dc_plugin(int irq, void *data);
 irqreturn_t smblib_handle_high_duty_cycle(int irq, void *data);
+irqreturn_t smblib_handle_switcher_power_ok(int irq, void *data);
 
 int smblib_get_prop_input_suspend(struct smb_charger *chg,
 				union power_supply_propval *val);