linux-kernel - [PATCH v1 3/4] usb: typec: ucsi: Set power role based on UCSI charge control

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Message-ID: <20240717004949.3638557-4-jthies@google.com>
Date: Wed, 17 Jul 2024 00:49:48 +0000
From: Jameson Thies <jthies@...gle.com>
To: heikki.krogerus@...ux.intel.com, linux-usb@...r.kernel.org
Cc: jthies@...gle.com, bleung@...gle.com, abhishekpandit@...omium.org, 
	andersson@...nel.org, dmitry.baryshkov@...aro.org, 
	fabrice.gasnier@...s.st.com, gregkh@...uxfoundation.org, hdegoede@...hat.com, 
	neil.armstrong@...aro.org, rajaram.regupathy@...el.com, 
	saranya.gopal@...el.com, linux-kernel@...r.kernel.org
Subject: [PATCH v1 3/4] usb: typec: ucsi: Set power role based on UCSI charge control

Add POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX as a property to the UCSI
power supply driver. When set to a negative value, set power role to
TYPEC_SOURCE, otherwise set the power role to TYPEC_SINK.

Signed-off-by: Jameson Thies <jthies@...gle.com>
---
 drivers/usb/typec/ucsi/psy.c | 46 ++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/usb/typec/ucsi/psy.c b/drivers/usb/typec/ucsi/psy.c
index 45113e013696..feb344cb7ac8 100644
--- a/drivers/usb/typec/ucsi/psy.c
+++ b/drivers/usb/typec/ucsi/psy.c
@@ -30,6 +30,7 @@ static enum power_supply_property ucsi_psy_props[] = {
 	POWER_SUPPLY_PROP_CURRENT_NOW,
 	POWER_SUPPLY_PROP_SCOPE,
 	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
 };
 
 static int ucsi_psy_get_scope(struct ucsi_connector *con,
@@ -270,11 +271,54 @@ static int ucsi_psy_get_prop(struct power_supply *psy,
 		return ucsi_psy_get_scope(con, val);
 	case POWER_SUPPLY_PROP_STATUS:
 		return ucsi_psy_get_status(con, val);
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+		val->intval = 0;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ucsi_psy_set_charge_control_limit_max(struct ucsi_connector *con,
+				 const union power_supply_propval *val)
+{
+	enum typec_role role;
+	/*
+	 * Writing a negative value to the charge control limit max implies the
+	 * port should not accept charge. Set the power role to source for a
+	 * negative charge control limit, and sink otherwise.
+	 */
+	if (val->intval < 0)
+		role = TYPEC_SOURCE;
+	else
+		role = TYPEC_SINK;
+
+	if (!con->typec_cap.ops || !con->typec_cap.ops->pr_set)
+		return -EINVAL;
+
+	return con->typec_cap.ops->pr_set(con->port, role);
+}
+
+static int ucsi_psy_set_prop(struct power_supply *psy,
+			     enum power_supply_property psp,
+			     const union power_supply_propval *val)
+{
+	struct ucsi_connector *con = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+		return ucsi_psy_set_charge_control_limit_max(con, val);
 	default:
 		return -EINVAL;
 	}
 }
 
+static int ucsi_psy_prop_is_writeable(struct power_supply *psy,
+			     enum power_supply_property psp)
+{
+	return psp == POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX;
+}
+
 static enum power_supply_usb_type ucsi_psy_usb_types[] = {
 	POWER_SUPPLY_USB_TYPE_C,
 	POWER_SUPPLY_USB_TYPE_PD,
@@ -303,6 +347,8 @@ int ucsi_register_port_psy(struct ucsi_connector *con)
 	con->psy_desc.properties = ucsi_psy_props;
 	con->psy_desc.num_properties = ARRAY_SIZE(ucsi_psy_props);
 	con->psy_desc.get_property = ucsi_psy_get_prop;
+	con->psy_desc.set_property = ucsi_psy_set_prop;
+	con->psy_desc.property_is_writeable = ucsi_psy_prop_is_writeable;
 
 	con->psy = power_supply_register(dev, &con->psy_desc, &psy_cfg);
 
-- 
2.45.2.1089.g2a221341d9-goog