platform/chrome: cros_typec_switch: Register mode switches

Register mode switch devices for Type-C connectors, when they are
specified by firmware. These control Type-C configuration for any USB
Type-C mode switches (sometimes known as "muxes") which are controlled
by the ChromeOS EC.
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20220816214857.2088914-6-pmalani@chromium.org

drivers/platform/chrome/cros_typec_switch.c

@@ -15,6 +15,7 @@
 #include <linux/platform_device.h>
 #include <linux/usb/typec_altmode.h>
 #include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_mux.h>
 #include <linux/usb/typec_retimer.h>
 
 #define DRV_NAME "cros-typec-switch"
@@ -22,6 +23,7 @@
 /* Handles and other relevant data required for each port's switches. */
 struct cros_typec_port {
 	int port_num;
+	struct typec_mux_dev *mode_switch;
 	struct typec_retimer *retimer;
 	struct cros_typec_switch_data *sdata;
 };
@@ -143,6 +145,15 @@ static int cros_typec_configure_mux(struct cros_typec_switch_data *sdata, int po
 	return -ETIMEDOUT;
 }
 
+static int cros_typec_mode_switch_set(struct typec_mux_dev *mode_switch,
+				      struct typec_mux_state *state)
+{
+	struct cros_typec_port *port = typec_mux_get_drvdata(mode_switch);
+
+	/* Mode switches have index 0. */
+	return cros_typec_configure_mux(port->sdata, port->port_num, 0, state->mode, state->alt);
+}
+
 static int cros_typec_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state)
 {
 	struct cros_typec_port *port = typec_retimer_get_drvdata(retimer);
@@ -159,9 +170,27 @@ static void cros_typec_unregister_switches(struct cros_typec_switch_data *sdata)
 		if (!sdata->ports[i])
 			continue;
 		typec_retimer_unregister(sdata->ports[i]->retimer);
+		typec_mux_unregister(sdata->ports[i]->mode_switch);
 	}
 }
 
+static int cros_typec_register_mode_switch(struct cros_typec_port *port,
+					   struct fwnode_handle *fwnode)
+{
+	struct typec_mux_desc mode_switch_desc = {
+		.fwnode = fwnode,
+		.drvdata = port,
+		.name = fwnode_get_name(fwnode),
+		.set = cros_typec_mode_switch_set,
+	};
+
+	port->mode_switch = typec_mux_register(port->sdata->dev, &mode_switch_desc);
+	if (IS_ERR(port->mode_switch))
+		return PTR_ERR(port->mode_switch);
+
+	return 0;
+}
+
 static int cros_typec_register_retimer(struct cros_typec_port *port, struct fwnode_handle *fwnode)
 {
 	struct typec_retimer_desc retimer_desc = {
@@ -230,6 +259,17 @@ static int cros_typec_register_switches(struct cros_typec_switch_data *sdata)
 		}
 
 		dev_dbg(dev, "Retimer switch registered for index %llu\n", index);
+
+		if (!device_property_present(fwnode->dev, "mode-switch"))
+			continue;
+
+		ret = cros_typec_register_mode_switch(port, fwnode);
+		if (ret) {
+			dev_err(dev, "Mode switch register failed\n");
+			goto err_switch;
+		}
+
+		dev_dbg(dev, "Mode switch registered for index %llu\n", index);
 	}
 
 	return 0;