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 * 143 usb_acpi_get_companion_for_port(struct usb_port *port_dev) 144 { 145 struct usb_device *udev; 146 struct acpi_device *adev; 147 acpi_handle *parent_handle; 148 int port1; 149 150 /* Get the struct usb_device point of port's hub */ 151 udev = to_usb_device(port_dev->dev.parent->parent); 152 153 /* 154 * The root hub ports' parent is the root hub. The non-root-hub 155 * ports' parent is the parent hub port which the hub is 156 * connected to. 157 */ 158 if (!udev->parent) { 159 adev = ACPI_COMPANION(&udev->dev); 160 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus), 161 port_dev->portnum); 162 } else { 163 parent_handle = usb_get_hub_port_acpi_handle(udev->parent, 164 udev->portnum); 165 if (!parent_handle) 166 return NULL; 167 168 acpi_bus_get_device(parent_handle, &adev); 169 port1 = port_dev->portnum; 170 } 171 172 return usb_acpi_find_port(adev, port1); 173 } 174 175 static struct acpi_device * 176 usb_acpi_find_companion_for_port(struct usb_port *port_dev) 177 { 178 struct acpi_device *adev; 179 struct acpi_pld_info *pld; 180 acpi_handle *handle; 181 acpi_status status; 182 183 adev = usb_acpi_get_companion_for_port(port_dev); 184 if (!adev) 185 return NULL; 186 187 handle = adev->handle; 188 status = acpi_get_physical_device_location(handle, &pld); 189 if (!ACPI_FAILURE(status) && pld) { 190 port_dev->location = USB_ACPI_LOCATION_VALID 191 | pld->group_token << 8 | pld->group_position; 192 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld); 193 ACPI_FREE(pld); 194 } 195 196 return adev; 197 } 198 199 static struct acpi_device * 200 usb_acpi_find_companion_for_device(struct usb_device *udev) 201 { 202 struct acpi_device *adev; 203 struct usb_port *port_dev; 204 struct usb_hub *hub; 205 206 if (!udev->parent) { 207 /* root hub is only child (_ADR=0) under its parent, the HC */ 208 adev = ACPI_COMPANION(udev->dev.parent); 209 return acpi_find_child_device(adev, 0, false); 210 } 211 212 hub = usb_hub_to_struct_hub(udev->parent); 213 if (!hub) 214 return NULL; 215 216 /* 217 * This is an embedded USB device connected to a port and such 218 * devices share port's ACPI companion. 219 */ 220 port_dev = hub->ports[udev->portnum - 1]; 221 return usb_acpi_get_companion_for_port(port_dev); 222 } 223 224 static struct acpi_device *usb_acpi_find_companion(struct device *dev) 225 { 226 /* 227 * The USB hierarchy like following: 228 * 229 * Device (EHC1) 230 * Device (HUBN) 231 * Device (PR01) 232 * Device (PR11) 233 * Device (PR12) 234 * Device (FN12) 235 * Device (FN13) 236 * Device (PR13) 237 * ... 238 * where HUBN is root hub, and PRNN are USB ports and devices 239 * connected to them, and FNNN are individualk functions for 240 * connected composite USB devices. PRNN and FNNN may contain 241 * _CRS and other methods describing sideband resources for 242 * the connected device. 243 * 244 * On the kernel side both root hub and embedded USB devices are 245 * represented as instances of usb_device structure, and ports 246 * are represented as usb_port structures, so the whole process 247 * is split into 2 parts: finding companions for devices and 248 * finding companions for ports. 249 * 250 * Note that we do not handle individual functions of composite 251 * devices yet, for that we would need to assign companions to 252 * devices corresponding to USB interfaces. 253 */ 254 if (is_usb_device(dev)) 255 return usb_acpi_find_companion_for_device(to_usb_device(dev)); 256 else if (is_usb_port(dev)) 257 return usb_acpi_find_companion_for_port(to_usb_port(dev)); 258 259 return NULL; 260 } 261 262 static bool usb_acpi_bus_match(struct device *dev) 263 { 264 return is_usb_device(dev) || is_usb_port(dev); 265 } 266 267 static struct acpi_bus_type usb_acpi_bus = { 268 .name = "USB", 269 .match = usb_acpi_bus_match, 270 .find_companion = usb_acpi_find_companion, 271 }; 272 273 int usb_acpi_register(void) 274 { 275 return register_acpi_bus_type(&usb_acpi_bus); 276 } 277 278 void usb_acpi_unregister(void) 279 { 280 unregister_acpi_bus_type(&usb_acpi_bus); 281 } 282