// SPDX-License-Identifier: GPL-2.0/* * Copyright 2022 Google LLC * * USB Type-C Retimer support. * Author: Prashant Malani <pmalani@chromium.org> * */ #include <linux/device.h>#include <linux/list.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/property.h>#include <linux/slab.h> #include "class.h"#include "retimer.h" static int retimer_fwnode_match(struct device *dev, const void *fwnode){	return is_typec_retimer(dev) && device_match_fwnode(dev, fwnode);} static void *typec_retimer_match(const struct fwnode_handle *fwnode, const char *id, void *data){	struct device *dev; 	if (id && !fwnode_property_present(fwnode, id))		return NULL; 	dev = class_find_device(&retimer_class, NULL, fwnode,				retimer_fwnode_match); 	return dev ? to_typec_retimer(dev) : ERR_PTR(-EPROBE_DEFER);} /** * fwnode_typec_retimer_get - Find USB Type-C retimer. * @fwnode: The caller device node. * * Finds a retimer linked to the caller. This function is primarily meant for the * Type-C drivers. Returns a reference to the retimer on success, NULL if no * matching connection was found, or ERR_PTR(-EPROBE_DEFER) when a connection * was found but the retimer has not been enumerated yet. */struct typec_retimer *fwnode_typec_retimer_get(struct fwnode_handle *fwnode){	struct typec_retimer *retimer; 	retimer = fwnode_connection_find_match(fwnode, "retimer-switch", NULL, typec_retimer_match);	if (!IS_ERR_OR_NULL(retimer))		WARN_ON(!try_module_get(retimer->dev.parent->driver->owner)); 	return retimer;}EXPORT_SYMBOL_GPL(fwnode_typec_retimer_get); /** * typec_retimer_put - Release handle to a retimer. * @retimer: USB Type-C Connector Retimer. * * Decrements reference count for @retimer. */void typec_retimer_put(struct typec_retimer *retimer){	if (!IS_ERR_OR_NULL(retimer)) {		module_put(retimer->dev.parent->driver->owner);		put_device(&retimer->dev);	}}EXPORT_SYMBOL_GPL(typec_retimer_put); int typec_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state){	if (IS_ERR_OR_NULL(retimer))		return 0; 	return retimer->set(retimer, state);}EXPORT_SYMBOL_GPL(typec_retimer_set); static void typec_retimer_release(struct device *dev){	kfree(to_typec_retimer(dev));} const struct device_type typec_retimer_dev_type = {	.name = "typec_retimer",	.release = typec_retimer_release,}; /** * typec_retimer_register - Register a retimer device. * @parent: Parent device. * @desc: Retimer description. * * Some USB Type-C connectors have their physical lines routed through retimers before they * reach muxes or host controllers. In some cases (for example: using alternate modes) * these retimers need to be reconfigured appropriately. This function registers retimer * switches which route and potentially modify the signals on the Type C physical lines * enroute to the host controllers. */struct typec_retimer *typec_retimer_register(struct device *parent, const struct typec_retimer_desc *desc){	struct typec_retimer *retimer;	int ret; 	if (!desc || !desc->set)		return ERR_PTR(-EINVAL); 	retimer = kzalloc_obj(*retimer);	if (!retimer)		return ERR_PTR(-ENOMEM); 	retimer->set = desc->set; 	device_initialize(&retimer->dev);	retimer->dev.parent = parent;	retimer->dev.fwnode = desc->fwnode;	retimer->dev.class = &retimer_class;	retimer->dev.type = &typec_retimer_dev_type;	retimer->dev.driver_data = desc->drvdata;	dev_set_name(&retimer->dev, "%s-retimer",		     desc->name ? desc->name : dev_name(parent)); 	ret = device_add(&retimer->dev);	if (ret) {		dev_err(parent, "failed to register retimer (%d)\n", ret);		put_device(&retimer->dev);		return ERR_PTR(ret);	} 	return retimer;}EXPORT_SYMBOL_GPL(typec_retimer_register); /** * typec_retimer_unregister - Unregister retimer device. * @retimer: USB Type-C Connector retimer. * * Unregister retimer that was registered with typec_retimer_register(). */void typec_retimer_unregister(struct typec_retimer *retimer){	if (!IS_ERR_OR_NULL(retimer))		device_unregister(&retimer->dev);}EXPORT_SYMBOL_GPL(typec_retimer_unregister); void *typec_retimer_get_drvdata(struct typec_retimer *retimer){	return dev_get_drvdata(&retimer->dev);}EXPORT_SYMBOL_GPL(typec_retimer_get_drvdata); const struct class retimer_class = {	.name = "retimer",};