linux/drivers/usb/core/usb-acpi.c
Dmitry Torokhov b4dfbbd180 usb: assign ACPI companions for embedded USB devices
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>
2019-01-25 08:46:26 +01:00

282 lines
7.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* USB-ACPI glue code
*
* Copyright 2012 Red Hat <mjg@redhat.com>
*/
#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)
{
acpi_handle port_handle;
int port1 = index + 1;
port_handle = usb_get_hub_port_acpi_handle(hdev,
port1);
if (port_handle)
return acpi_bus_power_manageable(port_handle);
else
return false;
}
EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
/**
* 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)
{
struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
struct usb_port *port_dev;
acpi_handle port_handle;
unsigned char state;
int port1 = index + 1;
int error = -EINVAL;
if (!hub)
return -ENODEV;
port_dev = hub->ports[port1 - 1];
port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
if (!port_handle)
return error;
if (enable)
state = ACPI_STATE_D0;
else
state = ACPI_STATE_D3_COLD;
error = acpi_bus_set_power(port_handle, state);
if (!error)
dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
else
dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
return error;
}
EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
struct acpi_pld_info *pld)
{
enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *upc;
acpi_status status;
/*
* According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
* is user visible and _UPC indicates whether it is connectable. If
* the port was visible and connectable, it could be freely connected
* and disconnected with USB devices. If no visible and connectable,
* a usb device is directly hard-wired to the port. If no visible and
* no connectable, the port would be not used.
*/
status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
upc = buffer.pointer;
if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
|| upc->package.count != 4) {
goto out;
}
if (upc->package.elements[0].integer.value)
if (pld->user_visible)
connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
else
connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
else if (!pld->user_visible)
connect_type = USB_PORT_NOT_USED;
out:
kfree(upc);
return connect_type;
}
/*
* 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 (1 << 31)
static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
int raw)
{
struct acpi_device *adev;
if (!parent)
return NULL;
list_for_each_entry(adev, &parent->children, node) {
if (acpi_device_adr(adev) == raw)
return adev;
}
return acpi_find_child_device(parent, raw, false);
}
static struct acpi_device *
usb_acpi_get_companion_for_port(struct usb_port *port_dev)
{
struct usb_device *udev;
struct acpi_device *adev;
acpi_handle *parent_handle;
int port1;
/* Get the struct usb_device point of port's hub */
udev = to_usb_device(port_dev->dev.parent->parent);
/*
* The root hub ports' parent is the root hub. The non-root-hub
* ports' parent is the parent hub port which the hub is
* connected to.
*/
if (!udev->parent) {
adev = ACPI_COMPANION(&udev->dev);
port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
port_dev->portnum);
} else {
parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
udev->portnum);
if (!parent_handle)
return NULL;
acpi_bus_get_device(parent_handle, &adev);
port1 = port_dev->portnum;
}
return usb_acpi_find_port(adev, port1);
}
static struct acpi_device *
usb_acpi_find_companion_for_port(struct usb_port *port_dev)
{
struct acpi_device *adev;
struct acpi_pld_info *pld;
acpi_handle *handle;
acpi_status status;
adev = usb_acpi_get_companion_for_port(port_dev);
if (!adev)
return NULL;
handle = adev->handle;
status = acpi_get_physical_device_location(handle, &pld);
if (!ACPI_FAILURE(status) && pld) {
port_dev->location = USB_ACPI_LOCATION_VALID
| pld->group_token << 8 | pld->group_position;
port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
ACPI_FREE(pld);
}
return adev;
}
static struct acpi_device *
usb_acpi_find_companion_for_device(struct usb_device *udev)
{
struct acpi_device *adev;
struct usb_port *port_dev;
struct usb_hub *hub;
if (!udev->parent) {
/* root hub is only child (_ADR=0) under its parent, the HC */
adev = ACPI_COMPANION(udev->dev.parent);
return acpi_find_child_device(adev, 0, false);
}
hub = usb_hub_to_struct_hub(udev->parent);
if (!hub)
return NULL;
/*
* This is an embedded USB device connected to a port and such
* devices share port's ACPI companion.
*/
port_dev = hub->ports[udev->portnum - 1];
return usb_acpi_get_companion_for_port(port_dev);
}
static struct acpi_device *usb_acpi_find_companion(struct device *dev)
{
/*
* The USB hierarchy like following:
*
* Device (EHC1)
* Device (HUBN)
* Device (PR01)
* Device (PR11)
* Device (PR12)
* Device (FN12)
* Device (FN13)
* Device (PR13)
* ...
* where HUBN is root hub, and PRNN are USB ports and devices
* connected to them, and FNNN are individualk functions for
* connected composite USB devices. PRNN and FNNN may contain
* _CRS and other methods describing sideband resources for
* the connected device.
*
* On the kernel side both root hub and embedded USB devices are
* represented as instances of usb_device structure, and ports
* are represented as usb_port structures, so the whole process
* is split into 2 parts: finding companions for devices and
* finding companions for ports.
*
* Note that we do not handle individual functions of composite
* devices yet, for that we would need to assign companions to
* devices corresponding to USB interfaces.
*/
if (is_usb_device(dev))
return usb_acpi_find_companion_for_device(to_usb_device(dev));
else if (is_usb_port(dev))
return usb_acpi_find_companion_for_port(to_usb_port(dev));
return NULL;
}
static bool usb_acpi_bus_match(struct device *dev)
{
return is_usb_device(dev) || is_usb_port(dev);
}
static struct acpi_bus_type usb_acpi_bus = {
.name = "USB",
.match = usb_acpi_bus_match,
.find_companion = usb_acpi_find_companion,
};
int usb_acpi_register(void)
{
return register_acpi_bus_type(&usb_acpi_bus);
}
void usb_acpi_unregister(void)
{
unregister_acpi_bus_type(&usb_acpi_bus);
}