drivers/usb/core/usb-acpi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * USB-ACPI glue code
   4  *
   5  * Copyright 2012 Red Hat <mjg@redhat.com>
   6  */
   7 #include <linux/module.h>
   8 #include <linux/usb.h>
   9 #include <linux/device.h>
  10 #include <linux/errno.h>
  11 #include <linux/kernel.h>
  12 #include <linux/acpi.h>
  13 #include <linux/pci.h>
  14 #include <linux/usb/hcd.h>
  15
  16 #include "hub.h"
  17
  18 /**
  19  * usb_acpi_power_manageable - check whether usb port has
  20  * acpi power resource.
  21  * @hdev: USB device belonging to the usb hub
  22  * @index: port index based zero
  23  *
  24  * Return true if the port has acpi power resource and false if no.
  25  */
  26 bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
  27 {
  28         acpi_handle port_handle;
  29         int port1 = index + 1;
  30
  31         port_handle = usb_get_hub_port_acpi_handle(hdev,
  32                 port1);
  33         if (port_handle)
  34                 return acpi_bus_power_manageable(port_handle);
  35         else
  36                 return false;
  37 }
  38 EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
  39
  40 /**
  41  * usb_acpi_set_power_state - control usb port's power via acpi power
  42  * resource
  43  * @hdev: USB device belonging to the usb hub
  44  * @index: port index based zero
  45  * @enable: power state expected to be set
  46  *
  47  * Notice to use usb_acpi_power_manageable() to check whether the usb port
  48  * has acpi power resource before invoking this function.
  49  *
  50  * Returns 0 on success, else negative errno.
  51  */
  52 int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
  53 {
  54         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
  55         struct usb_port *port_dev;
  56         acpi_handle port_handle;
  57         unsigned char state;
  58         int port1 = index + 1;
  59         int error = -EINVAL;
  60
  61         if (!hub)
  62                 return -ENODEV;
  63         port_dev = hub->ports[port1 - 1];
  64
  65         port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
  66         if (!port_handle)
  67                 return error;
  68
  69         if (enable)
  70                 state = ACPI_STATE_D0;
  71         else
  72                 state = ACPI_STATE_D3_COLD;
  73
  74         error = acpi_bus_set_power(port_handle, state);
  75         if (!error)
  76                 dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
  77         else
  78                 dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
  79
  80         return error;
  81 }
  82 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
  83
  84 static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
  85                 struct acpi_pld_info *pld)
  86 {
  87         enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
  88         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  89         union acpi_object *upc;
  90         acpi_status status;
  91
  92         /*
  93          * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
  94          * is user visible and _UPC indicates whether it is connectable. If
  95          * the port was visible and connectable, it could be freely connected
  96          * and disconnected with USB devices. If no visible and connectable,
  97          * a usb device is directly hard-wired to the port. If no visible and
  98          * no connectable, the port would be not used.
  99          */
 100         status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
 101         upc = buffer.pointer;
 102         if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
 103                 || upc->package.count != 4) {
 104                 goto out;
 105         }
 106
 107         if (upc->package.elements[0].integer.value)
 108                 if (pld->user_visible)
 109                         connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
 110                 else
 111                         connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
 112         else if (!pld->user_visible)
 113                 connect_type = USB_PORT_NOT_USED;
 114 out:
 115         kfree(upc);
 116         return connect_type;
 117 }
 118
 119
 120 /*
 121  * Private to usb-acpi, all the core needs to know is that
 122  * port_dev->location is non-zero when it has been set by the firmware.
 123  */
 124 #define USB_ACPI_LOCATION_VALID (1 << 31)
 125
 126 static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
 127                                               int raw)
 128 {
 129         struct acpi_device *adev;
 130
 131         if (!parent)
 132                 return NULL;
 133
 134         list_for_each_entry(adev, &parent->children, node) {
 135                 if (acpi_device_adr(adev) == raw)
 136                         return adev;
 137         }
 138
 139         return acpi_find_child_device(parent, raw, false);
 140 }
 141
 142 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
 143 {
 144         struct usb_device *udev;
 145         struct acpi_device *adev;
 146         acpi_handle *parent_handle;
 147
 148         /*
 149          * In the ACPI DSDT table, only usb root hub and usb ports are
 150          * acpi device nodes. The hierarchy like following.
 151          * Device (EHC1)
 152          *      Device (HUBN)
 153          *              Device (PR01)
 154          *                      Device (PR11)
 155          *                      Device (PR12)
 156          *                      Device (PR13)
 157          *                      ...
 158          * So all binding process is divided into two parts. binding
 159          * root hub and usb ports.
 160          */
 161         if (is_usb_device(dev)) {
 162                 udev = to_usb_device(dev);
 163                 if (udev->parent)
 164                         return NULL;
 165
 166                 /* root hub is only child (_ADR=0) under its parent, the HC */
 167                 adev = ACPI_COMPANION(dev->parent);
 168                 return acpi_find_child_device(adev, 0, false);
 169         } else if (is_usb_port(dev)) {
 170                 struct usb_port *port_dev = to_usb_port(dev);
 171                 int port1 = port_dev->portnum;
 172                 struct acpi_pld_info *pld;
 173                 acpi_handle *handle;
 174                 acpi_status status;
 175
 176                 /* Get the struct usb_device point of port's hub */
 177                 udev = to_usb_device(dev->parent->parent);
 178
 179                 /*
 180                  * The root hub ports' parent is the root hub. The non-root-hub
 181                  * ports' parent is the parent hub port which the hub is
 182                  * connected to.
 183                  */
 184                 if (!udev->parent) {
 185                         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
 186                         int raw;
 187
 188                         raw = usb_hcd_find_raw_port_number(hcd, port1);
 189
 190                         adev = usb_acpi_find_port(ACPI_COMPANION(&udev->dev),
 191                                                   raw);
 192
 193                         if (!adev)
 194                                 return NULL;
 195                 } else {
 196                         parent_handle =
 197                                 usb_get_hub_port_acpi_handle(udev->parent,
 198                                 udev->portnum);
 199                         if (!parent_handle)
 200                                 return NULL;
 201
 202                         acpi_bus_get_device(parent_handle, &adev);
 203
 204                         adev = usb_acpi_find_port(adev, port1);
 205
 206                         if (!adev)
 207                                 return NULL;
 208                 }
 209                 handle = adev->handle;
 210                 status = acpi_get_physical_device_location(handle, &pld);
 211                 if (ACPI_FAILURE(status) || !pld)
 212                         return adev;
 213
 214                 port_dev->location = USB_ACPI_LOCATION_VALID
 215                         | pld->group_token << 8 | pld->group_position;
 216                 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
 217                 ACPI_FREE(pld);
 218
 219                 return adev;
 220         }
 221
 222         return NULL;
 223 }
 224
 225 static bool usb_acpi_bus_match(struct device *dev)
 226 {
 227         return is_usb_device(dev) || is_usb_port(dev);
 228 }
 229
 230 static struct acpi_bus_type usb_acpi_bus = {
 231         .name = "USB",
 232         .match = usb_acpi_bus_match,
 233         .find_companion = usb_acpi_find_companion,
 234 };
 235
 236 int usb_acpi_register(void)
 237 {
 238         return register_acpi_bus_type(&usb_acpi_bus);
 239 }
 240
 241 void usb_acpi_unregister(void)
 242 {
 243         unregister_acpi_bus_type(&usb_acpi_bus);
 244 }