![Dmitry Torokhov](/assets/img/avatar_default.png)
USB devices permanently connected to USB ports may be described in ACPI tables and share ACPI devices with ports they are connected to. See [1] for details. This will allow us to describe sideband resources for devices, such as, for example, hard reset line for BT USB controllers. [1] https://docs.microsoft.com/en-us/windows-hardware/drivers/bringup/other-acpi-namespace-objects#acpi-namespace-hierarchy-and-adr-for-embedded-usb-devices Signed-off-by: Dmitry Torokhov <dtor@chromium.org> Signed-off-by: Rajat Jain <rajatja@google.com> (changed how we get the usb_port) Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Sukumar Ghorai <sukumar.ghorai@intel.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
282 lines
7.3 KiB
C
282 lines
7.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* USB-ACPI glue code
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*
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* Copyright 2012 Red Hat <mjg@redhat.com>
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*/
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#include <linux/module.h>
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#include <linux/usb.h>
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#include <linux/device.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/acpi.h>
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#include <linux/pci.h>
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#include <linux/usb/hcd.h>
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#include "hub.h"
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/**
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* usb_acpi_power_manageable - check whether usb port has
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* acpi power resource.
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* @hdev: USB device belonging to the usb hub
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* @index: port index based zero
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*
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* Return true if the port has acpi power resource and false if no.
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*/
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bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
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{
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acpi_handle port_handle;
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int port1 = index + 1;
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port_handle = usb_get_hub_port_acpi_handle(hdev,
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port1);
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if (port_handle)
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return acpi_bus_power_manageable(port_handle);
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else
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return false;
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}
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EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
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/**
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* usb_acpi_set_power_state - control usb port's power via acpi power
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* resource
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* @hdev: USB device belonging to the usb hub
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* @index: port index based zero
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* @enable: power state expected to be set
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*
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* Notice to use usb_acpi_power_manageable() to check whether the usb port
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* has acpi power resource before invoking this function.
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*
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* Returns 0 on success, else negative errno.
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*/
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int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
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{
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struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
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struct usb_port *port_dev;
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acpi_handle port_handle;
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unsigned char state;
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int port1 = index + 1;
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int error = -EINVAL;
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if (!hub)
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return -ENODEV;
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port_dev = hub->ports[port1 - 1];
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port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
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if (!port_handle)
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return error;
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if (enable)
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state = ACPI_STATE_D0;
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else
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state = ACPI_STATE_D3_COLD;
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error = acpi_bus_set_power(port_handle, state);
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if (!error)
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dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
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else
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dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
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return error;
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}
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EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
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static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
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struct acpi_pld_info *pld)
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{
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enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
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struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
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union acpi_object *upc;
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acpi_status status;
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/*
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* According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
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* is user visible and _UPC indicates whether it is connectable. If
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* the port was visible and connectable, it could be freely connected
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* and disconnected with USB devices. If no visible and connectable,
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* a usb device is directly hard-wired to the port. If no visible and
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* no connectable, the port would be not used.
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*/
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status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
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upc = buffer.pointer;
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if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
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|| upc->package.count != 4) {
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goto out;
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}
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if (upc->package.elements[0].integer.value)
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if (pld->user_visible)
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connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
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else
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connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
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else if (!pld->user_visible)
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connect_type = USB_PORT_NOT_USED;
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out:
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kfree(upc);
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return connect_type;
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}
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/*
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* Private to usb-acpi, all the core needs to know is that
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* port_dev->location is non-zero when it has been set by the firmware.
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*/
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#define USB_ACPI_LOCATION_VALID (1 << 31)
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static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
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int raw)
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{
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struct acpi_device *adev;
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if (!parent)
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return NULL;
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list_for_each_entry(adev, &parent->children, node) {
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if (acpi_device_adr(adev) == raw)
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return adev;
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}
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return acpi_find_child_device(parent, raw, false);
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}
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static struct acpi_device *
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usb_acpi_get_companion_for_port(struct usb_port *port_dev)
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{
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struct usb_device *udev;
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struct acpi_device *adev;
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acpi_handle *parent_handle;
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int port1;
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/* Get the struct usb_device point of port's hub */
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udev = to_usb_device(port_dev->dev.parent->parent);
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/*
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* The root hub ports' parent is the root hub. The non-root-hub
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* ports' parent is the parent hub port which the hub is
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* connected to.
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*/
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if (!udev->parent) {
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adev = ACPI_COMPANION(&udev->dev);
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port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
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port_dev->portnum);
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} else {
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parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
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udev->portnum);
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if (!parent_handle)
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return NULL;
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acpi_bus_get_device(parent_handle, &adev);
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port1 = port_dev->portnum;
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}
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return usb_acpi_find_port(adev, port1);
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}
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static struct acpi_device *
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usb_acpi_find_companion_for_port(struct usb_port *port_dev)
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{
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struct acpi_device *adev;
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struct acpi_pld_info *pld;
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acpi_handle *handle;
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acpi_status status;
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adev = usb_acpi_get_companion_for_port(port_dev);
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if (!adev)
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return NULL;
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handle = adev->handle;
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status = acpi_get_physical_device_location(handle, &pld);
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if (!ACPI_FAILURE(status) && pld) {
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port_dev->location = USB_ACPI_LOCATION_VALID
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| pld->group_token << 8 | pld->group_position;
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port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
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ACPI_FREE(pld);
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}
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return adev;
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}
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static struct acpi_device *
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usb_acpi_find_companion_for_device(struct usb_device *udev)
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{
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struct acpi_device *adev;
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struct usb_port *port_dev;
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struct usb_hub *hub;
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if (!udev->parent) {
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/* root hub is only child (_ADR=0) under its parent, the HC */
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adev = ACPI_COMPANION(udev->dev.parent);
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return acpi_find_child_device(adev, 0, false);
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}
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hub = usb_hub_to_struct_hub(udev->parent);
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if (!hub)
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return NULL;
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/*
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* This is an embedded USB device connected to a port and such
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* devices share port's ACPI companion.
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*/
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port_dev = hub->ports[udev->portnum - 1];
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return usb_acpi_get_companion_for_port(port_dev);
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}
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static struct acpi_device *usb_acpi_find_companion(struct device *dev)
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{
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/*
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* The USB hierarchy like following:
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*
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* Device (EHC1)
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* Device (HUBN)
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* Device (PR01)
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* Device (PR11)
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* Device (PR12)
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* Device (FN12)
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* Device (FN13)
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* Device (PR13)
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* ...
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* where HUBN is root hub, and PRNN are USB ports and devices
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* connected to them, and FNNN are individualk functions for
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* connected composite USB devices. PRNN and FNNN may contain
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* _CRS and other methods describing sideband resources for
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* the connected device.
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*
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* On the kernel side both root hub and embedded USB devices are
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* represented as instances of usb_device structure, and ports
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* are represented as usb_port structures, so the whole process
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* is split into 2 parts: finding companions for devices and
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* finding companions for ports.
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*
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* Note that we do not handle individual functions of composite
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* devices yet, for that we would need to assign companions to
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* devices corresponding to USB interfaces.
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*/
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if (is_usb_device(dev))
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return usb_acpi_find_companion_for_device(to_usb_device(dev));
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else if (is_usb_port(dev))
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return usb_acpi_find_companion_for_port(to_usb_port(dev));
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return NULL;
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}
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static bool usb_acpi_bus_match(struct device *dev)
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{
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return is_usb_device(dev) || is_usb_port(dev);
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}
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static struct acpi_bus_type usb_acpi_bus = {
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.name = "USB",
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.match = usb_acpi_bus_match,
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.find_companion = usb_acpi_find_companion,
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};
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int usb_acpi_register(void)
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{
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return register_acpi_bus_type(&usb_acpi_bus);
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}
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void usb_acpi_unregister(void)
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{
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unregister_acpi_bus_type(&usb_acpi_bus);
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}
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