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 = NULL; 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 if (ACPI_FAILURE(status)) 102 goto out; 103 104 upc = buffer.pointer; 105 if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4) 106 goto out; 107 108 if (upc->package.elements[0].integer.value) 109 if (pld->user_visible) 110 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG; 111 else 112 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED; 113 else if (!pld->user_visible) 114 connect_type = USB_PORT_NOT_USED; 115 out: 116 kfree(upc); 117 return connect_type; 118 } 119 120 121 /* 122 * Private to usb-acpi, all the core needs to know is that 123 * port_dev->location is non-zero when it has been set by the firmware. 124 */ 125 #define USB_ACPI_LOCATION_VALID (1 << 31) 126 127 static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent, 128 int raw) 129 { 130 struct acpi_device *adev; 131 132 if (!parent) 133 return NULL; 134 135 list_for_each_entry(adev, &parent->children, node) { 136 if (acpi_device_adr(adev) == raw) 137 return adev; 138 } 139 140 return acpi_find_child_device(parent, raw, false); 141 } 142 143 static struct acpi_device * 144 usb_acpi_get_companion_for_port(struct usb_port *port_dev) 145 { 146 struct usb_device *udev; 147 struct acpi_device *adev; 148 acpi_handle *parent_handle; 149 int port1; 150 151 /* Get the struct usb_device point of port's hub */ 152 udev = to_usb_device(port_dev->dev.parent->parent); 153 154 /* 155 * The root hub ports' parent is the root hub. The non-root-hub 156 * ports' parent is the parent hub port which the hub is 157 * connected to. 158 */ 159 if (!udev->parent) { 160 adev = ACPI_COMPANION(&udev->dev); 161 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus), 162 port_dev->portnum); 163 } else { 164 parent_handle = usb_get_hub_port_acpi_handle(udev->parent, 165 udev->portnum); 166 if (!parent_handle) 167 return NULL; 168 169 adev = acpi_fetch_acpi_dev(parent_handle); 170 port1 = port_dev->portnum; 171 } 172 173 return usb_acpi_find_port(adev, port1); 174 } 175 176 static struct acpi_device * 177 usb_acpi_find_companion_for_port(struct usb_port *port_dev) 178 { 179 struct acpi_device *adev; 180 struct acpi_pld_info *pld; 181 acpi_handle *handle; 182 acpi_status status; 183 184 adev = usb_acpi_get_companion_for_port(port_dev); 185 if (!adev) 186 return NULL; 187 188 handle = adev->handle; 189 status = acpi_get_physical_device_location(handle, &pld); 190 if (ACPI_SUCCESS(status) && pld) { 191 port_dev->location = USB_ACPI_LOCATION_VALID 192 | pld->group_token << 8 | pld->group_position; 193 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld); 194 ACPI_FREE(pld); 195 } 196 197 return adev; 198 } 199 200 static struct acpi_device * 201 usb_acpi_find_companion_for_device(struct usb_device *udev) 202 { 203 struct acpi_device *adev; 204 struct usb_port *port_dev; 205 struct usb_hub *hub; 206 207 if (!udev->parent) { 208 /* root hub is only child (_ADR=0) under its parent, the HC */ 209 adev = ACPI_COMPANION(udev->dev.parent); 210 return acpi_find_child_device(adev, 0, false); 211 } 212 213 hub = usb_hub_to_struct_hub(udev->parent); 214 if (!hub) 215 return NULL; 216 217 /* 218 * This is an embedded USB device connected to a port and such 219 * devices share port's ACPI companion. 220 */ 221 port_dev = hub->ports[udev->portnum - 1]; 222 return usb_acpi_get_companion_for_port(port_dev); 223 } 224 225 static struct acpi_device *usb_acpi_find_companion(struct device *dev) 226 { 227 /* 228 * The USB hierarchy like following: 229 * 230 * Device (EHC1) 231 * Device (HUBN) 232 * Device (PR01) 233 * Device (PR11) 234 * Device (PR12) 235 * Device (FN12) 236 * Device (FN13) 237 * Device (PR13) 238 * ... 239 * where HUBN is root hub, and PRNN are USB ports and devices 240 * connected to them, and FNNN are individualk functions for 241 * connected composite USB devices. PRNN and FNNN may contain 242 * _CRS and other methods describing sideband resources for 243 * the connected device. 244 * 245 * On the kernel side both root hub and embedded USB devices are 246 * represented as instances of usb_device structure, and ports 247 * are represented as usb_port structures, so the whole process 248 * is split into 2 parts: finding companions for devices and 249 * finding companions for ports. 250 * 251 * Note that we do not handle individual functions of composite 252 * devices yet, for that we would need to assign companions to 253 * devices corresponding to USB interfaces. 254 */ 255 if (is_usb_device(dev)) 256 return usb_acpi_find_companion_for_device(to_usb_device(dev)); 257 else if (is_usb_port(dev)) 258 return usb_acpi_find_companion_for_port(to_usb_port(dev)); 259 260 return NULL; 261 } 262 263 static bool usb_acpi_bus_match(struct device *dev) 264 { 265 return is_usb_device(dev) || is_usb_port(dev); 266 } 267 268 static struct acpi_bus_type usb_acpi_bus = { 269 .name = "USB", 270 .match = usb_acpi_bus_match, 271 .find_companion = usb_acpi_find_companion, 272 }; 273 274 int usb_acpi_register(void) 275 { 276 return register_acpi_bus_type(&usb_acpi_bus); 277 } 278 279 void usb_acpi_unregister(void) 280 { 281 unregister_acpi_bus_type(&usb_acpi_bus); 282 } 283