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 * 128 usb_acpi_get_companion_for_port(struct usb_port *port_dev) 129 { 130 struct usb_device *udev; 131 struct acpi_device *adev; 132 acpi_handle *parent_handle; 133 int port1; 134 135 /* Get the struct usb_device point of port's hub */ 136 udev = to_usb_device(port_dev->dev.parent->parent); 137 138 /* 139 * The root hub ports' parent is the root hub. The non-root-hub 140 * ports' parent is the parent hub port which the hub is 141 * connected to. 142 */ 143 if (!udev->parent) { 144 adev = ACPI_COMPANION(&udev->dev); 145 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus), 146 port_dev->portnum); 147 } else { 148 parent_handle = usb_get_hub_port_acpi_handle(udev->parent, 149 udev->portnum); 150 if (!parent_handle) 151 return NULL; 152 153 adev = acpi_fetch_acpi_dev(parent_handle); 154 port1 = port_dev->portnum; 155 } 156 157 return acpi_find_child_by_adr(adev, port1); 158 } 159 160 static struct acpi_device * 161 usb_acpi_find_companion_for_port(struct usb_port *port_dev) 162 { 163 struct acpi_device *adev; 164 struct acpi_pld_info *pld; 165 acpi_handle *handle; 166 acpi_status status; 167 168 adev = usb_acpi_get_companion_for_port(port_dev); 169 if (!adev) 170 return NULL; 171 172 handle = adev->handle; 173 status = acpi_get_physical_device_location(handle, &pld); 174 if (ACPI_SUCCESS(status) && pld) { 175 port_dev->location = USB_ACPI_LOCATION_VALID 176 | pld->group_token << 8 | pld->group_position; 177 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld); 178 ACPI_FREE(pld); 179 } 180 181 return adev; 182 } 183 184 static struct acpi_device * 185 usb_acpi_find_companion_for_device(struct usb_device *udev) 186 { 187 struct acpi_device *adev; 188 struct usb_port *port_dev; 189 struct usb_hub *hub; 190 191 if (!udev->parent) { 192 /* 193 * root hub is only child (_ADR=0) under its parent, the HC. 194 * sysdev pointer is the HC as seen from firmware. 195 */ 196 adev = ACPI_COMPANION(udev->bus->sysdev); 197 return acpi_find_child_device(adev, 0, false); 198 } 199 200 hub = usb_hub_to_struct_hub(udev->parent); 201 if (!hub) 202 return NULL; 203 204 /* 205 * This is an embedded USB device connected to a port and such 206 * devices share port's ACPI companion. 207 */ 208 port_dev = hub->ports[udev->portnum - 1]; 209 return usb_acpi_get_companion_for_port(port_dev); 210 } 211 212 static struct acpi_device *usb_acpi_find_companion(struct device *dev) 213 { 214 /* 215 * The USB hierarchy like following: 216 * 217 * Device (EHC1) 218 * Device (HUBN) 219 * Device (PR01) 220 * Device (PR11) 221 * Device (PR12) 222 * Device (FN12) 223 * Device (FN13) 224 * Device (PR13) 225 * ... 226 * where HUBN is root hub, and PRNN are USB ports and devices 227 * connected to them, and FNNN are individualk functions for 228 * connected composite USB devices. PRNN and FNNN may contain 229 * _CRS and other methods describing sideband resources for 230 * the connected device. 231 * 232 * On the kernel side both root hub and embedded USB devices are 233 * represented as instances of usb_device structure, and ports 234 * are represented as usb_port structures, so the whole process 235 * is split into 2 parts: finding companions for devices and 236 * finding companions for ports. 237 * 238 * Note that we do not handle individual functions of composite 239 * devices yet, for that we would need to assign companions to 240 * devices corresponding to USB interfaces. 241 */ 242 if (is_usb_device(dev)) 243 return usb_acpi_find_companion_for_device(to_usb_device(dev)); 244 else if (is_usb_port(dev)) 245 return usb_acpi_find_companion_for_port(to_usb_port(dev)); 246 247 return NULL; 248 } 249 250 static bool usb_acpi_bus_match(struct device *dev) 251 { 252 return is_usb_device(dev) || is_usb_port(dev); 253 } 254 255 static struct acpi_bus_type usb_acpi_bus = { 256 .name = "USB", 257 .match = usb_acpi_bus_match, 258 .find_companion = usb_acpi_find_companion, 259 }; 260 261 int usb_acpi_register(void) 262 { 263 return register_acpi_bus_type(&usb_acpi_bus); 264 } 265 266 void usb_acpi_unregister(void) 267 { 268 unregister_acpi_bus_type(&usb_acpi_bus); 269 } 270