linux/drivers/usb/typec/retimer.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2022 Google LLC
 *
 * USB Type-C Retimer support.
 * Author: Prashant Malani <[email protected]>
 *
 */

#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)
{ … }

static void *typec_retimer_match(const struct fwnode_handle *fwnode, const char *id, void *data)
{ … }

/**
 * 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)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL_GPL(…);

int typec_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state)
{ … }
EXPORT_SYMBOL_GPL(…);

static void typec_retimer_release(struct device *dev)
{ … }

const struct device_type typec_retimer_dev_type = …;

/**
 * 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)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL_GPL(…);

void *typec_retimer_get_drvdata(struct typec_retimer *retimer)
{ … }
EXPORT_SYMBOL_GPL(…);

const struct class retimer_class = …;