[PATCH 3/4] usb: typec: tcpci_maxim: configure charging & data paths

[Badhri Jagan Sridharan <badhri@google.com>]

This change allows the driver to configure input current/voltage
limit for the charging path. The driver sets current_max and voltage_max
values of the power supply identified through chg-psy-name.

The change also exposes the data_role and the orientation as a extcon
interface for configuring the USB data controller.

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
 drivers/usb/typec/tcpm/tcpci_maxim.c | 126 ++++++++++++++++++++++++++-
 1 file changed, 125 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c b/drivers/usb/typec/tcpm/tcpci_maxim.c
index 041a1c393594..365ff4c18146 100644
--- a/drivers/usb/typec/tcpm/tcpci_maxim.c
+++ b/drivers/usb/typec/tcpm/tcpci_maxim.c
@@ -7,8 +7,11 @@
 
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
+#include <linux/extcon.h>
+#include <linux/extcon-provider.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/power_supply.h>
 #include <linux/regmap.h>
 #include <linux/usb/pd.h>
 #include <linux/usb/tcpm.h>
@@ -46,6 +49,10 @@ struct max_tcpci_chip {
 	struct device *dev;
 	struct i2c_client *client;
 	struct tcpm_port *port;
+	bool pd_capable;
+	bool attached;
+	struct power_supply *chg_psy;
+	struct extcon_dev *extcon;
 };
 
 static const struct regmap_range max_tcpci_tcpci_range[] = {
@@ -439,11 +446,92 @@ static int tcpci_init(struct tcpci *tcpci, struct tcpci_data *data)
 	return -1;
 }
 
+static int max_tcpci_get_current_limit(struct tcpci *tcpci, struct tcpci_data *data)
+{
+	struct max_tcpci_chip *chip = tdata_to_max_tcpci(data);
+	union power_supply_propval val = {0};
+	int ret;
+
+	if (!chip->chg_psy)
+		return 0;
+
+	ret = power_supply_get_property(chip->chg_psy, POWER_SUPPLY_PROP_CURRENT_MAX, &val);
+	return ret < 0 ? ret : val.intval;
+}
+
+static int max_tcpci_set_current_limit(struct tcpci *tcpci, struct tcpci_data *data, u32 max_ma,
+				       u32 mv)
+{
+	struct max_tcpci_chip *chip = tdata_to_max_tcpci(data);
+	union power_supply_propval val;
+	int ret;
+
+	if (!chip->chg_psy)
+		return 0;
+
+	val.intval = mv;
+	ret = power_supply_set_property(chip->chg_psy, POWER_SUPPLY_PROP_VOLTAGE_MAX, &val);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Disregard 0mA vote for Rp-default value. Rp-default current values
+	 * would be inferred from other sources such BC1.2 and data stack.
+	 */
+	if (!chip->pd_capable && max_ma == 0 && chip->attached)
+		return 0;
+
+	val.intval = max_ma;
+	return power_supply_set_property(chip->chg_psy, POWER_SUPPLY_PROP_CURRENT_MAX, &val);
+}
+
+static void max_tcpci_set_pd_capable(struct tcpci *tcpci, struct tcpci_data *data, bool capable)
+{
+	struct max_tcpci_chip *chip = tdata_to_max_tcpci(data);
+
+	chip->pd_capable = capable;
+}
+
+static void max_tcpci_set_roles(struct tcpci *tcpci, struct tcpci_data *data, bool attached,
+				enum typec_role role, enum typec_data_role data_role)
+{
+	struct max_tcpci_chip *chip = tdata_to_max_tcpci(data);
+
+	chip->attached = attached;
+
+	if (!attached) {
+		extcon_set_state_sync(chip->extcon, EXTCON_USB_HOST, 0);
+		extcon_set_state_sync(chip->extcon, EXTCON_USB, 0);
+		return;
+	}
+
+	extcon_set_state_sync(chip->extcon, data_role == TYPEC_HOST ? EXTCON_USB_HOST : EXTCON_USB,
+			      1);
+}
+
+static void max_tcpci_set_cc_polarity(struct tcpci *tcpci, struct tcpci_data *data,
+				      enum typec_cc_polarity polarity)
+{
+	struct max_tcpci_chip *chip = tdata_to_max_tcpci(data);
+
+	extcon_set_property(chip->extcon, EXTCON_USB, EXTCON_PROP_USB_TYPEC_POLARITY,
+			    (union extcon_property_value)(int)polarity);
+	extcon_set_property(chip->extcon, EXTCON_USB_HOST, EXTCON_PROP_USB_TYPEC_POLARITY,
+			    (union extcon_property_value)(int)polarity);
+}
+
+static const unsigned int usbpd_extcon[] = {
+	EXTCON_USB,
+	EXTCON_USB_HOST,
+};
+
 static int max_tcpci_probe(struct i2c_client *client, const struct i2c_device_id *i2c_id)
 {
 	int ret;
 	struct max_tcpci_chip *chip;
 	u8 power_status;
+	char *chg_psy_name;
+	struct device_node *dn;
 
 	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
@@ -472,6 +560,11 @@ static int max_tcpci_probe(struct i2c_client *client, const struct i2c_device_id
 	chip->data.auto_discharge_disconnect = true;
 	chip->data.vbus_vsafe0v = true;
 	chip->data.set_partner_usb_comm_capable = max_tcpci_set_partner_usb_comm_capable;
+	chip->data.get_current_limit = max_tcpci_get_current_limit;
+	chip->data.set_current_limit = max_tcpci_set_current_limit;
+	chip->data.set_pd_capable = max_tcpci_set_pd_capable;
+	chip->data.set_roles = max_tcpci_set_roles;
+	chip->data.set_cc_polarity = max_tcpci_set_cc_polarity;
 
 	max_tcpci_init_regs(chip);
 	chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
@@ -484,9 +577,38 @@ static int max_tcpci_probe(struct i2c_client *client, const struct i2c_device_id
 	if (ret < 0)
 		goto unreg_port;
 
+	dn = dev_of_node(&client->dev);
+	if (!dn) {
+		dev_err(&client->dev, "of node not found\n");
+		ret = -EINVAL;
+		goto unreg_port;
+	}
+	chg_psy_name = (char *)of_get_property(dn, "chg-psy-name", NULL);
+	if (chg_psy_name)
+		chip->chg_psy = power_supply_get_by_name(chg_psy_name);
+
+	chip->extcon = devm_extcon_dev_allocate(&client->dev, usbpd_extcon);
+	if (IS_ERR(chip->extcon)) {
+		dev_err(&client->dev, "Error allocating extcon: %ld\n", PTR_ERR(chip->extcon));
+		ret = PTR_ERR(chip->extcon);
+		goto psy_put;
+	}
+
+	ret = devm_extcon_dev_register(&client->dev, chip->extcon);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to register extcon device");
+		goto psy_put;
+	}
+
+	extcon_set_property_capability(chip->extcon, EXTCON_USB, EXTCON_PROP_USB_TYPEC_POLARITY);
+	extcon_set_property_capability(chip->extcon, EXTCON_USB_HOST,
+				       EXTCON_PROP_USB_TYPEC_POLARITY);
+
 	device_init_wakeup(chip->dev, true);
 	return 0;
-
+psy_put:
+	if (chip->chg_psy)
+		power_supply_put(chip->chg_psy);
 unreg_port:
 	tcpci_unregister_port(chip->tcpci);
 
@@ -499,6 +621,8 @@ static int max_tcpci_remove(struct i2c_client *client)
 
 	if (!IS_ERR_OR_NULL(chip->tcpci))
 		tcpci_unregister_port(chip->tcpci);
+	if (chip->chg_psy)
+		power_supply_put(chip->chg_psy);
 
 	return 0;
 }
-- 
2.31.0.rc2.261.g7f71774620-goog