[PATCH 2/4] usb: typec: wire USB role changes to OTG device

[Sascha Hauer]

When a Type-C controller reports a USB role change via typec_set_role(),
find the associated OTG device via the OF graph and set its dr_mode
accordingly.

Since the Type-C controller may probe before the OTG device registers,
a late_initcall sweeps all known ports and applies any role that was not
yet forwarded.

Co-Authored-By: Claude Sonnet 4.6 <noreply at anthropic.com>
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 drivers/usb/typec/class.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index e03eaccbb9..b88e1c1e46 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -8,10 +8,15 @@
 
 #include <module.h>
 #include <driver.h>
+#include <init.h>
 #include <linux/kernel.h>
+#include <linux/list.h>
 #include <linux/usb/role.h>
 #include <linux/usb/typec.h>
 #include <linux/usb/typec_altmode.h>
+#include <linux/usb/usb.h>
+#include <linux/device/bus.h>
+#include <of_graph.h>
 #include <param.h>
 
 enum typec_param_accessory {
@@ -22,12 +27,16 @@ enum typec_param_accessory {
 
 struct typec_port {
 	struct device dev;
+	struct list_head list;
 	const struct typec_operations *ops;
 	int pwr_role;		/* enum typec_role */
 	int usb_role;		/* enum usb_role role */
 	int accessory;		/* enum typec_param_accessory */
+	bool otg_role_applied;
 };
 
+static LIST_HEAD(typec_port_list);
+
 /**
  * typec_set_pwr_role - Report power role change
  * @port: The USB Type-C Port where the role was changed
@@ -68,6 +77,41 @@ int typec_set_mode(struct typec_port *port, int mode)
 }
 EXPORT_SYMBOL_GPL(typec_set_mode);
 
+static bool typec_apply_otg_role(struct typec_port *port)
+{
+	struct device_node *connector = port->dev.of_node;
+	struct device_node *ep, *remote;
+	struct device *dev;
+	enum usb_dr_mode dr_mode;
+	bool applied = false;
+
+	if (!IS_ENABLED(CONFIG_USB_OTGDEV) || !connector)
+		return false;
+
+	if (port->usb_role == USB_ROLE_HOST)
+		dr_mode = USB_DR_MODE_HOST;
+	else if (port->usb_role == USB_ROLE_DEVICE)
+		dr_mode = USB_DR_MODE_PERIPHERAL;
+	else
+		return false;
+
+	for_each_endpoint_of_node(connector, ep) {
+		remote = of_graph_get_remote_port_parent(ep);
+		if (!remote)
+			continue;
+
+		bus_for_each_device(&otg_bus_type, dev) {
+			if (dev->parent && dev->parent->of_node == remote) {
+				otg_device_set_dr_mode(dev, dr_mode);
+				applied = true;
+				break;
+			}
+		}
+	}
+
+	return applied;
+}
+
 /**
  * typec_set_role - Set USB role for a Type-C connector
  * @port: USB Type-C connector
@@ -79,10 +123,24 @@ EXPORT_SYMBOL_GPL(typec_set_mode);
 int typec_set_role(struct typec_port *port, enum usb_role role)
 {
 	port->usb_role = role;
+	port->otg_role_applied = typec_apply_otg_role(port);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(typec_set_role);
 
+static int typec_apply_otg_roles(void)
+{
+	struct typec_port *port;
+
+	list_for_each_entry(port, &typec_port_list, list) {
+		if (!port->otg_role_applied)
+			port->otg_role_applied = typec_apply_otg_role(port);
+	}
+
+	return 0;
+}
+late_initcall(typec_apply_otg_roles);
+
 /**
  * typec_get_drvdata - Return private driver data pointer
  * @port: USB Type-C port
@@ -165,6 +223,8 @@ struct typec_port *typec_register_port(struct device *parent,
 	if (dev->of_node)
 		dev->of_node->dev = dev;
 
+	list_add_tail(&port->list, &typec_port_list);
+
 	dev_add_param_enum(dev, "usb_role", param_set_readonly, typec_param_update,
 			   &port->usb_role, usb_role_names,
 			   ARRAY_SIZE(usb_role_names), port);

-- 
2.47.3