qpnp-smb2: implement PE_START property

The policy engine needs to be informed that its time to start
its activities when APSD results are available and/or PD_ALLOWED
is decided. USB type property shouldn't change after that.

Since HVDCP_TIMEOUT_VOTER is the last one to cast its allow vote
in the sequence, use it to reflect the PE_START property.

While at it since PE_START property is returned assuming an atomic
context, the read of PD_ALLOWED could be moved to its sleepable
variants. This aids in keeping the policy engine code simple and also
assures race free code.

Change-Id: Ib98ac10d87200a2fd5492e27399f696f2468eba6
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>

3 files changed, 23 insertions, 10 deletions

diff --git a/drivers/power/qcom-charger/qpnp-smb2.c b/drivers/power/qcom-charger/qpnp-smb2.c
index d5dbd6374ace..4cb4c2bd665c 100644
--- a/drivers/power/qcom-charger/qpnp-smb2.c
+++ b/drivers/power/qcom-charger/qpnp-smb2.c
@@ -351,6 +351,7 @@ static enum power_supply_property smb2_usb_props[] = {
 	POWER_SUPPLY_PROP_PD_ACTIVE,
 	POWER_SUPPLY_PROP_INPUT_CURRENT_SETTLED,
 	POWER_SUPPLY_PROP_INPUT_CURRENT_NOW,
+	POWER_SUPPLY_PROP_PE_START,
 };
 
 static int smb2_usb_get_prop(struct power_supply *psy,
@@ -422,6 +423,9 @@ static int smb2_usb_get_prop(struct power_supply *psy,
 	case POWER_SUPPLY_PROP_PD_USB_SUSPEND_SUPPORTED:
 		val->intval = chg->system_suspend_supported;
 		break;
+	case POWER_SUPPLY_PROP_PE_START:
+		rc = smblib_get_pe_start(chg, val);
+		break;
 	default:
 		pr_err("get prop %d is not supported\n", psp);
 		rc = -EINVAL;
diff --git a/drivers/power/qcom-charger/smb-lib.c b/drivers/power/qcom-charger/smb-lib.c
index 5f9775cc0fee..4b57c1a002c2 100644
--- a/drivers/power/qcom-charger/smb-lib.c
+++ b/drivers/power/qcom-charger/smb-lib.c
@@ -471,9 +471,8 @@ static int try_rerun_apsd_for_hvdcp(struct smb_charger *chg)
 	return 0;
 }
 
-static int smblib_update_usb_type(struct smb_charger *chg)
+static const struct apsd_result *smblib_update_usb_type(struct smb_charger *chg)
 {
-	int rc = 0;
 	const struct apsd_result *apsd_result;
 
 	/* if PD is active, APSD is disabled so won't have a valid result */
@@ -484,7 +483,7 @@ static int smblib_update_usb_type(struct smb_charger *chg)
 
 	apsd_result = smblib_get_apsd_result(chg);
 	chg->usb_psy_desc.type = apsd_result->pst;
-	return rc;
+	return apsd_result;
 }
 
 static int smblib_notifier_call(struct notifier_block *nb,
@@ -1767,7 +1766,7 @@ int smblib_get_prop_typec_power_role(struct smb_charger *chg,
 int smblib_get_prop_pd_allowed(struct smb_charger *chg,
 			       union power_supply_propval *val)
 {
-	val->intval = get_effective_result_locked(chg->pd_allowed_votable);
+	val->intval = get_effective_result(chg->pd_allowed_votable);
 	return 0;
 }
 
@@ -1793,6 +1792,19 @@ int smblib_get_prop_pd_in_hard_reset(struct smb_charger *chg,
 	return 0;
 }
 
+int smblib_get_pe_start(struct smb_charger *chg,
+			       union power_supply_propval *val)
+{
+	/*
+	 * hvdcp timeout voter is the last one to allow pd. Use its vote
+	 * to indicate start of pe engine
+	 */
+	val->intval
+		= !get_client_vote_locked(chg->pd_disallowed_votable_indirect,
+			HVDCP_TIMEOUT_VOTER);
+	return 0;
+}
+
 /*******************
  * USB PSY SETTERS *
  * *****************/
@@ -2298,13 +2310,12 @@ static void smblib_handle_hvdcp_detect_done(struct smb_charger *chg,
 #define HVDCP_DET_MS 2500
 static void smblib_handle_apsd_done(struct smb_charger *chg, bool rising)
 {
-	int rc;
 	const struct apsd_result *apsd_result;
 
 	if (!rising)
 		return;
 
-	apsd_result = smblib_get_apsd_result(chg);
+	apsd_result = smblib_update_usb_type(chg);
 	switch (apsd_result->bit) {
 	case SDP_CHARGER_BIT:
 	case CDP_CHARGER_BIT:
@@ -2323,10 +2334,6 @@ static void smblib_handle_apsd_done(struct smb_charger *chg, bool rising)
 		break;
 	}
 
-	rc = smblib_update_usb_type(chg);
-	if (rc < 0)
-		smblib_err(chg, "Couldn't update usb type rc=%d\n", rc);
-
 	smblib_dbg(chg, PR_INTERRUPT, "IRQ: apsd-done rising; %s detected\n",
 		   apsd_result->name);
 }
diff --git a/drivers/power/qcom-charger/smb-lib.h b/drivers/power/qcom-charger/smb-lib.h
index 77badf6c7ec1..fb8356d3bdba 100644
--- a/drivers/power/qcom-charger/smb-lib.h
+++ b/drivers/power/qcom-charger/smb-lib.h
@@ -309,6 +309,8 @@ int smblib_get_prop_input_current_settled(struct smb_charger *chg,
 				union power_supply_propval *val);
 int smblib_get_prop_pd_in_hard_reset(struct smb_charger *chg,
 			       union power_supply_propval *val);
+int smblib_get_pe_start(struct smb_charger *chg,
+			       union power_supply_propval *val);
 int smblib_get_prop_charger_temp(struct smb_charger *chg,
 				union power_supply_propval *val);
 int smblib_get_prop_charger_temp_max(struct smb_charger *chg,