path: root/drivers/usb/core/port.c

// SPDX-License-Identifier: GPL-2.0
/*
 * usb port device code
 *
 * Copyright (C) 2012 Intel Corp
 *
 * Author: Lan Tianyu <tianyu.lan@intel.com>
 */

#include <linux/kstrtox.h>
#include <linux/slab.h>
#include <linux/string_choices.h>
#include <linux/sysfs.h>
#include <linux/pm_qos.h>
#include <linux/component.h>
#include <linux/usb/of.h>

#include "hub.h"

static int usb_port_block_power_off;

static const struct attribute_group *port_dev_group[];

static ssize_t early_stop_show(struct device *dev,
			    struct device_attribute *attr, char *buf)
{
	struct usb_port *port_dev = to_usb_port(dev);

	return sysfs_emit(buf, "%s\n", str_yes_no(port_dev->early_stop));
}

static ssize_t early_stop_store(struct device *dev, struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct usb_port *port_dev = to_usb_port(dev);
	bool value;

	if (kstrtobool(buf, &value))
		return -EINVAL;

	if (value)
		port_dev->early_stop = 1;
	else
		port_dev->early_stop = 0;

	return count;
}
static DEVICE_ATTR_RW(early_stop);

static ssize_t disable_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct usb_port *port_dev = to_usb_port(dev);
	struct usb_device *hdev = to_usb_device(dev->parent->parent);
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
	struct usb_interface *intf = to_usb_interface(dev->parent);
	int port1 = port_dev->portnum;
	u16 portstatus, unused;
	bool disabled;
	int rc;
	struct kernfs_node *kn;

	if (!hub)
		return -ENODEV;
	hub_get(hub);
	rc = usb_autopm_get_interface(intf);
	if (rc < 0)
		goto out_hub_get;

	/*
	 * Prevent deadlock if another process is concurrently
	 * trying to unregister hdev.
	 */
	kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
	if (!kn) {
		rc = -ENODEV;
		goto out_autopm;
	}
	usb_lock_device(hdev);
	if (hub->disconnected) {
		rc = -ENODEV;
		goto out_hdev_lock;
	}

	usb_hub_port_status(hub, port1, &portstatus, &unused);
	disabled = !usb_port_is_power_on(hub, portstatus);

 out_hdev_lock:
	usb_unlock_device(hdev);
	sysfs_unbreak_active_protection(kn);
 out_autopm:
	usb_autopm_put_interface(intf);
 out_hub_get:
	hub_put(hub);

	if (rc)
		return rc;

	return sysfs_emit(buf, "%s\n", disabled ? "1" : "0");
}

static ssize_t disable_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct usb_port *port_dev = to_usb_port(dev);
	struct usb_device *hdev = to_usb_device(dev->parent->parent);
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
	struct usb_interface *intf = to_usb_interface(dev->parent);
	int port1 = port_dev->portnum;
	bool disabled;
	int rc;
	struct kernfs_node *kn;

	if (!hub)
		return -ENODEV;
	rc = kstrtobool(buf, &disabled);
	if (rc)
		return rc;

	hub_get(hub);
	rc = usb_autopm_get_interface(intf);
	if (rc < 0)
		goto out_hub_get;

	/*
	 * Prevent deadlock if another process is concurrently
	 * trying to unregister hdev.
	 */
	kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
	if (!kn) {
		rc = -ENODEV;
		goto out_autopm;
	}
	usb_lock_device(hdev);
	if (hub->disconnected) {
		rc = -ENODEV;
		goto out_hdev_lock;
	}

	if (disabled && port_dev->child)
		usb_disconnect(&port_dev->child);

	rc = usb_hub_set_port_power(hdev, hub, port1, !disabled);

	if (disabled) {
		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
		if (!port_dev->is_superspeed)
			usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
	}

	if (!rc)
		rc = count;

 out_hdev_lock:
	usb_unlock_device(hdev);
	sysfs_unbreak_active_protection(kn);
 out_autopm:
	usb_autopm_put_interface(intf);
 out_hub_get:
	hub_put(hub);

	return rc;
}
static DEVICE_ATTR_RW(disable);

static ssize_t location_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	struct usb_port *port_dev = to_usb_port(dev);

	return sysfs_emit(buf, "0x%08x\n