usb: typec: hd3ss3220: Enable VBUS based on ID pin state

There is a ID pin present on HD3SS3220 controller that can be routed
to SoC. As per the datasheet:

"Upon detecting a UFP device, HD3SS3220 will keep ID pin high if VBUS is
not at VSafe0V. Once VBUS is at VSafe0V, the HD3SS3220 will assert ID pin
low. This is done to enforce Type-C requirement that VBUS must be at
VSafe0V before re-enabling VBUS"

Add support to read the ID pin state and enable VBUS accordingly.

Signed-off-by: Krishna Kurapati <[e-mail]>
Reviewed-by: Heikki Krogerus <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/typec/hd3ss3220.c

···
 #include <linux/usb/typec.h>
 #include <linux/delay.h>
 #include <linux/workqueue.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+#include <linux/of_graph.h>
 
 #define HD3SS3220_REG_CN_STAT		0x08
 #define HD3SS3220_REG_CN_STAT_CTRL	0x09
···
 	struct delayed_work output_poll_work;
 	enum usb_role role_state;
 	bool poll;
+
+	struct gpio_desc *id_gpiod;
+	int id_irq;
+
+	struct regulator *vbus;
 };
 
 static int hd3ss3220_set_power_opmode(struct hd3ss3220 *hd3ss3220, int power_opmode)
···
 	.max_register = 0x0A,
 };
 
+static irqreturn_t hd3ss3220_id_isr(int irq, void *dev_id)
+{
+	struct hd3ss3220 *hd3ss3220 = dev_id;
+	int ret;
+	int id;
+
+	id = gpiod_get_value_cansleep(hd3ss3220->id_gpiod);
+	if (!id)
+		ret = regulator_enable(hd3ss3220->vbus);
+	else
+		ret = regulator_disable(hd3ss3220->vbus);
+
+	if (ret)
+		dev_err(hd3ss3220->dev,
+			"vbus regulator %s failed: %d\n", id ? "disable" : "enable", ret);
+
+	return IRQ_HANDLED;
+}
+
 static int hd3ss3220_probe(struct i2c_client *client)
 {
 	struct typec_capability typec_cap = { };
-	struct hd3ss3220 *hd3ss3220;
 	struct fwnode_handle *connector, *ep;
-	int ret;
+	struct hd3ss3220 *hd3ss3220;
+	struct regulator *vbus;
 	unsigned int data;
+	int ret;
 
 	hd3ss3220 = devm_kzalloc(&client->dev, sizeof(struct hd3ss3220),
 				 GFP_KERNEL);
···
 	if (IS_ERR(hd3ss3220->role_sw)) {
 		ret = PTR_ERR(hd3ss3220->role_sw);
 		goto err_put_fwnode;
+	}
+
+	vbus = devm_of_regulator_get_optional(hd3ss3220->dev,
+					      to_of_node(connector),
+					      "vbus");
+	if (IS_ERR(vbus) && vbus != ERR_PTR(-ENODEV)) {
+		ret = PTR_ERR(vbus);
+		dev_err(hd3ss3220->dev, "failed to get vbus: %d", ret);
+		goto err_put_fwnode;
+	}
+
+	hd3ss3220->vbus = (vbus == ERR_PTR(-ENODEV) ? NULL : vbus);
+
+	if (hd3ss3220->vbus) {
+		hd3ss3220->id_gpiod = devm_gpiod_get_optional(hd3ss3220->dev,
+							      "id",
+							      GPIOD_IN);
+		if (IS_ERR(hd3ss3220->id_gpiod)) {
+			ret = PTR_ERR(hd3ss3220->id_gpiod);
+			goto err_put_fwnode;
+		}
+	}
+
+	if (hd3ss3220->id_gpiod) {
+		hd3ss3220->id_irq = gpiod_to_irq(hd3ss3220->id_gpiod);
+		if (hd3ss3220->id_irq < 0) {
+			ret = hd3ss3220->id_irq;
+			dev_err(hd3ss3220->dev,
+				"failed to get ID gpio: %d\n",
+				hd3ss3220->id_irq);
+			goto err_put_fwnode;
+		}
+
+		ret = devm_request_threaded_irq(hd3ss3220->dev,
+						hd3ss3220->id_irq, NULL,
+						hd3ss3220_id_isr,
+						IRQF_TRIGGER_RISING |
+						IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+						dev_name(hd3ss3220->dev), hd3ss3220);
+		if (ret < 0) {
+			dev_err(hd3ss3220->dev, "failed to get ID irq: %d\n", ret);
+			goto err_put_fwnode;
+		}
 	}
 
 	typec_cap.prefer_role = TYPEC_NO_PREFERRED_ROLE;