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