linux/drivers/usb/core/usb-acpi.c

// SPDX-License-Identifier: GPL-2.0
/*
 * USB-ACPI glue code
 *
 * Copyright 2012 Red Hat <[email protected]>
 */
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/pci.h>
#include <linux/usb/hcd.h>

#include "hub.h"

/**
 * usb_acpi_power_manageable - check whether usb port has
 * acpi power resource.
 * @hdev: USB device belonging to the usb hub
 * @index: port index based zero
 *
 * Return true if the port has acpi power resource and false if no.
 */
bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
{ … }
EXPORT_SYMBOL_GPL(…);

#define UUID_USB_CONTROLLER_DSM …
#define USB_DSM_DISABLE_U1_U2_FOR_PORT …

/**
 * usb_acpi_port_lpm_incapable - check if lpm should be disabled for a port.
 * @hdev: USB device belonging to the usb hub
 * @index: zero based port index
 *
 * Some USB3 ports may not support USB3 link power management U1/U2 states
 * due to different retimer setup. ACPI provides _DSM method which returns 0x01
 * if U1 and U2 states should be disabled. Evaluate _DSM with:
 * Arg0: UUID = ce2ee385-00e6-48cb-9f05-2edb927c4899
 * Arg1: Revision ID = 0
 * Arg2: Function Index = 5
 * Arg3: (empty)
 *
 * Return 1 if USB3 port is LPM incapable, negative on error, otherwise 0
 */

int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * usb_acpi_set_power_state - control usb port's power via acpi power
 * resource
 * @hdev: USB device belonging to the usb hub
 * @index: port index based zero
 * @enable: power state expected to be set
 *
 * Notice to use usb_acpi_power_manageable() to check whether the usb port
 * has acpi power resource before invoking this function.
 *
 * Returns 0 on success, else negative errno.
 */
int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
{ … }
EXPORT_SYMBOL_GPL(…);

/*
 * Private to usb-acpi, all the core needs to know is that
 * port_dev->location is non-zero when it has been set by the firmware.
 */
#define USB_ACPI_LOCATION_VALID …

static void
usb_acpi_get_connect_type(struct usb_port *port_dev, acpi_handle *handle)
{ … }

static struct acpi_device *
usb_acpi_get_companion_for_port(struct usb_port *port_dev)
{ … }

static struct acpi_device *
usb_acpi_find_companion_for_port(struct usb_port *port_dev)
{ … }

static struct acpi_device *
usb_acpi_find_companion_for_device(struct usb_device *udev)
{ … }

static struct acpi_device *usb_acpi_find_companion(struct device *dev)
{ … }

static bool usb_acpi_bus_match(struct device *dev)
{ … }

static struct acpi_bus_type usb_acpi_bus = …;

int usb_acpi_register(void)
{ … }

void usb_acpi_unregister(void)
{ … }