usb/core/usb-acpi.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * USB-ACPI glue code
0004  *
0005  * Copyright 2012 Red Hat <mjg@redhat.com>
0006  */
0007 #include <linux/module.h>
0008 #include <linux/usb.h>
0009 #include <linux/device.h>
0010 #include <linux/errno.h>
0011 #include <linux/kernel.h>
0012 #include <linux/acpi.h>
0013 #include <linux/pci.h>
0014 #include <linux/usb/hcd.h>
0015
0016 #include "hub.h"
0017
0018 /**
0019  * usb_acpi_power_manageable - check whether usb port has
0020  * acpi power resource.
0021  * @hdev: USB device belonging to the usb hub
0022  * @index: port index based zero
0023  *
0024  * Return true if the port has acpi power resource and false if no.
0025  */
0026 bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
0027 {
0028     acpi_handle port_handle;
0029     int port1 = index + 1;
0030
0031     port_handle = usb_get_hub_port_acpi_handle(hdev,
0032         port1);
0033     if (port_handle)
0034         return acpi_bus_power_manageable(port_handle);
0035     else
0036         return false;
0037 }
0038 EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
0039
0040 /**
0041  * usb_acpi_set_power_state - control usb port's power via acpi power
0042  * resource
0043  * @hdev: USB device belonging to the usb hub
0044  * @index: port index based zero
0045  * @enable: power state expected to be set
0046  *
0047  * Notice to use usb_acpi_power_manageable() to check whether the usb port
0048  * has acpi power resource before invoking this function.
0049  *
0050  * Returns 0 on success, else negative errno.
0051  */
0052 int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
0053 {
0054     struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
0055     struct usb_port *port_dev;
0056     acpi_handle port_handle;
0057     unsigned char state;
0058     int port1 = index + 1;
0059     int error = -EINVAL;
0060
0061     if (!hub)
0062         return -ENODEV;
0063     port_dev = hub->ports[port1 - 1];
0064
0065     port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
0066     if (!port_handle)
0067         return error;
0068
0069     if (enable)
0070         state = ACPI_STATE_D0;
0071     else
0072         state = ACPI_STATE_D3_COLD;
0073
0074     error = acpi_bus_set_power(port_handle, state);
0075     if (!error)
0076         dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
0077     else
0078         dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
0079
0080     return error;
0081 }
0082 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
0083
0084 static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
0085         struct acpi_pld_info *pld)
0086 {
0087     enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
0088     struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
0089     union acpi_object *upc = NULL;
0090     acpi_status status;
0091
0092     /*
0093      * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
0094      * is user visible and _UPC indicates whether it is connectable. If
0095      * the port was visible and connectable, it could be freely connected
0096      * and disconnected with USB devices. If no visible and connectable,
0097      * a usb device is directly hard-wired to the port. If no visible and
0098      * no connectable, the port would be not used.
0099      */
0100     status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
0101     if (ACPI_FAILURE(status))
0102         goto out;
0103
0104     upc = buffer.pointer;
0105     if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
0106         goto out;
0107
0108     if (upc->package.elements[0].integer.value)
0109         if (pld->user_visible)
0110             connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
0111         else
0112             connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
0113     else if (!pld->user_visible)
0114         connect_type = USB_PORT_NOT_USED;
0115 out:
0116     kfree(upc);
0117     return connect_type;
0118 }
0119
0120
0121 /*
0122  * Private to usb-acpi, all the core needs to know is that
0123  * port_dev->location is non-zero when it has been set by the firmware.
0124  */
0125 #define USB_ACPI_LOCATION_VALID (1 << 31)
0126
0127 static struct acpi_device *
0128 usb_acpi_get_companion_for_port(struct usb_port *port_dev)
0129 {
0130     struct usb_device *udev;
0131     struct acpi_device *adev;
0132     acpi_handle *parent_handle;
0133     int port1;
0134
0135     /* Get the struct usb_device point of port's hub */
0136     udev = to_usb_device(port_dev->dev.parent->parent);
0137
0138     /*
0139      * The root hub ports' parent is the root hub. The non-root-hub
0140      * ports' parent is the parent hub port which the hub is
0141      * connected to.
0142      */
0143     if (!udev->parent) {
0144         adev = ACPI_COMPANION(&udev->dev);
0145         port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
0146                              port_dev->portnum);
0147     } else {
0148         parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
0149                                  udev->portnum);
0150         if (!parent_handle)
0151             return NULL;
0152
0153         adev = acpi_fetch_acpi_dev(parent_handle);
0154         port1 = port_dev->portnum;
0155     }
0156
0157     return acpi_find_child_by_adr(adev, port1);
0158 }
0159
0160 static struct acpi_device *
0161 usb_acpi_find_companion_for_port(struct usb_port *port_dev)
0162 {
0163     struct acpi_device *adev;
0164     struct acpi_pld_info *pld;
0165     acpi_handle *handle;
0166     acpi_status status;
0167
0168     adev = usb_acpi_get_companion_for_port(port_dev);
0169     if (!adev)
0170         return NULL;
0171
0172     handle = adev->handle;
0173     status = acpi_get_physical_device_location(handle, &pld);
0174     if (ACPI_SUCCESS(status) && pld) {
0175         port_dev->location = USB_ACPI_LOCATION_VALID
0176             | pld->group_token << 8 | pld->group_position;
0177         port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
0178         ACPI_FREE(pld);
0179     }
0180
0181     return adev;
0182 }
0183
0184 static struct acpi_device *
0185 usb_acpi_find_companion_for_device(struct usb_device *udev)
0186 {
0187     struct acpi_device *adev;
0188     struct usb_port *port_dev;
0189     struct usb_hub *hub;
0190
0191     if (!udev->parent) {
0192         /*
0193          * root hub is only child (_ADR=0) under its parent, the HC.
0194          * sysdev pointer is the HC as seen from firmware.
0195          */
0196         adev = ACPI_COMPANION(udev->bus->sysdev);
0197         return acpi_find_child_device(adev, 0, false);
0198     }
0199
0200     hub = usb_hub_to_struct_hub(udev->parent);
0201     if (!hub)
0202         return NULL;
0203
0204     /*
0205      * This is an embedded USB device connected to a port and such
0206      * devices share port's ACPI companion.
0207      */
0208     port_dev = hub->ports[udev->portnum - 1];
0209     return usb_acpi_get_companion_for_port(port_dev);
0210 }
0211
0212 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
0213 {
0214     /*
0215      * The USB hierarchy like following:
0216      *
0217      * Device (EHC1)
0218      *  Device (HUBN)
0219      *      Device (PR01)
0220      *          Device (PR11)
0221      *          Device (PR12)
0222      *              Device (FN12)
0223      *              Device (FN13)
0224      *          Device (PR13)
0225      *          ...
0226      * where HUBN is root hub, and PRNN are USB ports and devices
0227      * connected to them, and FNNN are individualk functions for
0228      * connected composite USB devices. PRNN and FNNN may contain
0229      * _CRS and other methods describing sideband resources for
0230      * the connected device.
0231      *
0232      * On the kernel side both root hub and embedded USB devices are
0233      * represented as instances of usb_device structure, and ports
0234      * are represented as usb_port structures, so the whole process
0235      * is split into 2 parts: finding companions for devices and
0236      * finding companions for ports.
0237      *
0238      * Note that we do not handle individual functions of composite
0239      * devices yet, for that we would need to assign companions to
0240      * devices corresponding to USB interfaces.
0241      */
0242     if (is_usb_device(dev))
0243         return usb_acpi_find_companion_for_device(to_usb_device(dev));
0244     else if (is_usb_port(dev))
0245         return usb_acpi_find_companion_for_port(to_usb_port(dev));
0246
0247     return NULL;
0248 }
0249
0250 static bool usb_acpi_bus_match(struct device *dev)
0251 {
0252     return is_usb_device(dev) || is_usb_port(dev);
0253 }
0254
0255 static struct acpi_bus_type usb_acpi_bus = {
0256     .name = "USB",
0257     .match = usb_acpi_bus_match,
0258     .find_companion = usb_acpi_find_companion,
0259 };
0260
0261 int usb_acpi_register(void)
0262 {
0263     return register_acpi_bus_type(&usb_acpi_bus);
0264 }
0265
0266 void usb_acpi_unregister(void)
0267 {
0268     unregister_acpi_bus_type(&usb_acpi_bus);
0269 }