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 #define UUID_USB_CONTROLLER_DSM "ce2ee385-00e6-48cb-9f05-2edb927c4899" 41 #define USB_DSM_DISABLE_U1_U2_FOR_PORT 5 42 43 /** 44 * usb_acpi_port_lpm_incapable - check if lpm should be disabled for a port. 45 * @hdev: USB device belonging to the usb hub 46 * @index: zero based port index 47 * 48 * Some USB3 ports may not support USB3 link power management U1/U2 states 49 * due to different retimer setup. ACPI provides _DSM method which returns 0x01 50 * if U1 and U2 states should be disabled. Evaluate _DSM with: 51 * Arg0: UUID = ce2ee385-00e6-48cb-9f05-2edb927c4899 52 * Arg1: Revision ID = 0 53 * Arg2: Function Index = 5 54 * Arg3: (empty) 55 * 56 * Return 1 if USB3 port is LPM incapable, negative on error, otherwise 0 57 */ 58 59 int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index) 60 { 61 union acpi_object *obj; 62 acpi_handle port_handle; 63 int port1 = index + 1; 64 guid_t guid; 65 int ret; 66 67 ret = guid_parse(UUID_USB_CONTROLLER_DSM, &guid); 68 if (ret) 69 return ret; 70 71 port_handle = usb_get_hub_port_acpi_handle(hdev, port1); 72 if (!port_handle) { 73 dev_dbg(&hdev->dev, "port-%d no acpi handle\n", port1); 74 return -ENODEV; 75 } 76 77 if (!acpi_check_dsm(port_handle, &guid, 0, 78 BIT(USB_DSM_DISABLE_U1_U2_FOR_PORT))) { 79 dev_dbg(&hdev->dev, "port-%d no _DSM function %d\n", 80 port1, USB_DSM_DISABLE_U1_U2_FOR_PORT); 81 return -ENODEV; 82 } 83 84 obj = acpi_evaluate_dsm(port_handle, &guid, 0, 85 USB_DSM_DISABLE_U1_U2_FOR_PORT, NULL); 86 87 if (!obj) 88 return -ENODEV; 89 90 if (obj->type != ACPI_TYPE_INTEGER) { 91 dev_dbg(&hdev->dev, "evaluate port-%d _DSM failed\n", port1); 92 ACPI_FREE(obj); 93 return -EINVAL; 94 } 95 96 if (obj->integer.value == 0x01) 97 ret = 1; 98 99 ACPI_FREE(obj); 100 101 return ret; 102 } 103 EXPORT_SYMBOL_GPL(usb_acpi_port_lpm_incapable); 104 105 /** 106 * usb_acpi_set_power_state - control usb port's power via acpi power 107 * resource 108 * @hdev: USB device belonging to the usb hub 109 * @index: port index based zero 110 * @enable: power state expected to be set 111 * 112 * Notice to use usb_acpi_power_manageable() to check whether the usb port 113 * has acpi power resource before invoking this function. 114 * 115 * Returns 0 on success, else negative errno. 116 */ 117 int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable) 118 { 119 struct usb_hub *hub = usb_hub_to_struct_hub(hdev); 120 struct usb_port *port_dev; 121 acpi_handle port_handle; 122 unsigned char state; 123 int port1 = index + 1; 124 int error = -EINVAL; 125 126 if (!hub) 127 return -ENODEV; 128 port_dev = hub->ports[port1 - 1]; 129 130 port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1); 131 if (!port_handle) 132 return error; 133 134 if (enable) 135 state = ACPI_STATE_D0; 136 else 137 state = ACPI_STATE_D3_COLD; 138 139 error = acpi_bus_set_power(port_handle, state); 140 if (!error) 141 dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable); 142 else 143 dev_dbg(&port_dev->dev, "acpi: power failed to be set\n"); 144 145 return error; 146 } 147 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state); 148 149 static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle, 150 struct acpi_pld_info *pld) 151 { 152 enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN; 153 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 154 union acpi_object *upc = NULL; 155 acpi_status status; 156 157 /* 158 * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port 159 * is user visible and _UPC indicates whether it is connectable. If 160 * the port was visible and connectable, it could be freely connected 161 * and disconnected with USB devices. If no visible and connectable, 162 * a usb device is directly hard-wired to the port. If no visible and 163 * no connectable, the port would be not used. 164 */ 165 status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer); 166 if (ACPI_FAILURE(status)) 167 goto out; 168 169 upc = buffer.pointer; 170 if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4) 171 goto out; 172 173 if (upc->package.elements[0].integer.value) 174 if (pld->user_visible) 175 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG; 176 else 177 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED; 178 else if (!pld->user_visible) 179 connect_type = USB_PORT_NOT_USED; 180 out: 181 kfree(upc); 182 return connect_type; 183 } 184 185 186 /* 187 * Private to usb-acpi, all the core needs to know is that 188 * port_dev->location is non-zero when it has been set by the firmware. 189 */ 190 #define USB_ACPI_LOCATION_VALID (1 << 31) 191 192 static struct acpi_device * 193 usb_acpi_get_companion_for_port(struct usb_port *port_dev) 194 { 195 struct usb_device *udev; 196 struct acpi_device *adev; 197 acpi_handle *parent_handle; 198 int port1; 199 200 /* Get the struct usb_device point of port's hub */ 201 udev = to_usb_device(port_dev->dev.parent->parent); 202 203 /* 204 * The root hub ports' parent is the root hub. The non-root-hub 205 * ports' parent is the parent hub port which the hub is 206 * connected to. 207 */ 208 if (!udev->parent) { 209 adev = ACPI_COMPANION(&udev->dev); 210 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus), 211 port_dev->portnum); 212 } else { 213 parent_handle = usb_get_hub_port_acpi_handle(udev->parent, 214 udev->portnum); 215 if (!parent_handle) 216 return NULL; 217 218 adev = acpi_fetch_acpi_dev(parent_handle); 219 port1 = port_dev->portnum; 220 } 221 222 return acpi_find_child_by_adr(adev, port1); 223 } 224 225 static struct acpi_device * 226 usb_acpi_find_companion_for_port(struct usb_port *port_dev) 227 { 228 struct acpi_device *adev; 229 struct acpi_pld_info *pld; 230 acpi_handle *handle; 231 acpi_status status; 232 233 adev = usb_acpi_get_companion_for_port(port_dev); 234 if (!adev) 235 return NULL; 236 237 handle = adev->handle; 238 status = acpi_get_physical_device_location(handle, &pld); 239 if (ACPI_SUCCESS(status) && pld) { 240 port_dev->location = USB_ACPI_LOCATION_VALID 241 | pld->group_token << 8 | pld->group_position; 242 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld); 243 ACPI_FREE(pld); 244 } 245 246 return adev; 247 } 248 249 static struct acpi_device * 250 usb_acpi_find_companion_for_device(struct usb_device *udev) 251 { 252 struct acpi_device *adev; 253 struct usb_port *port_dev; 254 struct usb_hub *hub; 255 256 if (!udev->parent) { 257 /* 258 * root hub is only child (_ADR=0) under its parent, the HC. 259 * sysdev pointer is the HC as seen from firmware. 260 */ 261 adev = ACPI_COMPANION(udev->bus->sysdev); 262 return acpi_find_child_device(adev, 0, false); 263 } 264 265 hub = usb_hub_to_struct_hub(udev->parent); 266 if (!hub) 267 return NULL; 268 269 /* 270 * This is an embedded USB device connected to a port and such 271 * devices share port's ACPI companion. 272 */ 273 port_dev = hub->ports[udev->portnum - 1]; 274 return usb_acpi_get_companion_for_port(port_dev); 275 } 276 277 static struct acpi_device *usb_acpi_find_companion(struct device *dev) 278 { 279 /* 280 * The USB hierarchy like following: 281 * 282 * Device (EHC1) 283 * Device (HUBN) 284 * Device (PR01) 285 * Device (PR11) 286 * Device (PR12) 287 * Device (FN12) 288 * Device (FN13) 289 * Device (PR13) 290 * ... 291 * where HUBN is root hub, and PRNN are USB ports and devices 292 * connected to them, and FNNN are individualk functions for 293 * connected composite USB devices. PRNN and FNNN may contain 294 * _CRS and other methods describing sideband resources for 295 * the connected device. 296 * 297 * On the kernel side both root hub and embedded USB devices are 298 * represented as instances of usb_device structure, and ports 299 * are represented as usb_port structures, so the whole process 300 * is split into 2 parts: finding companions for devices and 301 * finding companions for ports. 302 * 303 * Note that we do not handle individual functions of composite 304 * devices yet, for that we would need to assign companions to 305 * devices corresponding to USB interfaces. 306 */ 307 if (is_usb_device(dev)) 308 return usb_acpi_find_companion_for_device(to_usb_device(dev)); 309 else if (is_usb_port(dev)) 310 return usb_acpi_find_companion_for_port(to_usb_port(dev)); 311 312 return NULL; 313 } 314 315 static bool usb_acpi_bus_match(struct device *dev) 316 { 317 return is_usb_device(dev) || is_usb_port(dev); 318 } 319 320 static struct acpi_bus_type usb_acpi_bus = { 321 .name = "USB", 322 .match = usb_acpi_bus_match, 323 .find_companion = usb_acpi_find_companion, 324 }; 325 326 int usb_acpi_register(void) 327 { 328 return register_acpi_bus_type(&usb_acpi_bus); 329 } 330 331 void usb_acpi_unregister(void) 332 { 333 unregister_acpi_bus_type(&usb_acpi_bus); 334 } 335