linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * USB Role Switch Support

 *

 * Copyright (C) 2018 Intel Corporation

 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>

 *         Hans de Goede <hdegoede@redhat.com>

 */

​

#include <linux/usb/role.h>

#include <linux/property.h>

#include <linux/device.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/slab.h>

​

static struct class *role_class;

​

struct usb_role_switch {

    struct device dev;

    struct mutex lock; /* device lock*/

    enum usb_role role;

​

    /* From descriptor */

    struct device *usb2_port;

    struct device *usb3_port;

    struct device *udc;

    usb_role_switch_set_t set;

    usb_role_switch_get_t get;

    bool allow_userspace_control;

};

​

#define to_role_switch(d)   container_of(d, struct usb_role_switch, dev)

​

/**

 * usb_role_switch_set_role - Set USB role for a switch

 * @sw: USB role switch

 * @role: USB role to be switched to

 *

 * Set USB role @role for @sw.

 */

int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role)

{

    int ret;

​

    if (IS_ERR_OR_NULL(sw))

        return 0;

​

    mutex_lock(&sw->lock);

​

    ret = sw->set(sw->dev.parent, role);

    if (!ret)

        sw->role = role;

​

    mutex_unlock(&sw->lock);

​

    return ret;

}

EXPORT_SYMBOL_GPL(usb_role_switch_set_role);

​

/**

 * usb_role_switch_get_role - Get the USB role for a switch

 * @sw: USB role switch

 *

 * Depending on the role-switch-driver this function returns either a cached

 * value of the last set role, or reads back the actual value from the hardware.

 */

enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)

{

    enum usb_role role;

​

    if (IS_ERR_OR_NULL(sw))

        return USB_ROLE_NONE;

​

    mutex_lock(&sw->lock);

​

    if (sw->get)

        role = sw->get(sw->dev.parent);

    else

        role = sw->role;

​

    mutex_unlock(&sw->lock);

​

    return role;

}

EXPORT_SYMBOL_GPL(usb_role_switch_get_role);

​

static int switch_fwnode_match(struct device *dev, const void *fwnode)

{

    return dev_fwnode(dev) == fwnode;

}

​