1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * USB-ACPI glue code 4 * 5 * Copyright 2012 Red Hat <mjg@redhat.com> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the Free 9 * Software Foundation, version 2. 10 * 11 */ 12 #include <linux/module.h> 13 #include <linux/usb.h> 14 #include <linux/device.h> 15 #include <linux/errno.h> 16 #include <linux/kernel.h> 17 #include <linux/acpi.h> 18 #include <linux/pci.h> 19 #include <linux/usb/hcd.h> 20 21 #include "hub.h" 22 23 /** 24 * usb_acpi_power_manageable - check whether usb port has 25 * acpi power resource. 26 * @hdev: USB device belonging to the usb hub 27 * @index: port index based zero 28 * 29 * Return true if the port has acpi power resource and false if no. 30 */ 31 bool usb_acpi_power_manageable(struct usb_device *hdev, int index) 32 { 33 acpi_handle port_handle; 34 int port1 = index + 1; 35 36 port_handle = usb_get_hub_port_acpi_handle(hdev, 37 port1); 38 if (port_handle) 39 return acpi_bus_power_manageable(port_handle); 40 else 41 return false; 42 } 43 EXPORT_SYMBOL_GPL(usb_acpi_power_manageable); 44 45 /** 46 * usb_acpi_set_power_state - control usb port's power via acpi power 47 * resource 48 * @hdev: USB device belonging to the usb hub 49 * @index: port index based zero 50 * @enable: power state expected to be set 51 * 52 * Notice to use usb_acpi_power_manageable() to check whether the usb port 53 * has acpi power resource before invoking this function. 54 * 55 * Returns 0 on success, else negative errno. 56 */ 57 int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable) 58 { 59 struct usb_hub *hub = usb_hub_to_struct_hub(hdev); 60 struct usb_port *port_dev; 61 acpi_handle port_handle; 62 unsigned char state; 63 int port1 = index + 1; 64 int error = -EINVAL; 65 66 if (!hub) 67 return -ENODEV; 68 port_dev = hub->ports[port1 - 1]; 69 70 port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1); 71 if (!port_handle) 72 return error; 73 74 if (enable) 75 state = ACPI_STATE_D0; 76 else 77 state = ACPI_STATE_D3_COLD; 78 79 error = acpi_bus_set_power(port_handle, state); 80 if (!error) 81 dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable); 82 else 83 dev_dbg(&port_dev->dev, "acpi: power failed to be set\n"); 84 85 return error; 86 } 87 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state); 88 89 static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle, 90 struct acpi_pld_info *pld) 91 { 92 enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN; 93 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 94 union acpi_object *upc; 95 acpi_status status; 96 97 /* 98 * According to ACPI Spec 9.13. PLD indicates whether usb port is 99 * user visible and _UPC indicates whether it is connectable. If 100 * the port was visible and connectable, it could be freely connected 101 * and disconnected with USB devices. If no visible and connectable, 102 * a usb device is directly hard-wired to the port. If no visible and 103 * no connectable, the port would be not used. 104 */ 105 status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer); 106 upc = buffer.pointer; 107 if (!upc || (upc->type != ACPI_TYPE_PACKAGE) 108 || upc->package.count != 4) { 109 goto out; 110 } 111 112 if (upc->package.elements[0].integer.value) 113 if (pld->user_visible) 114 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG; 115 else 116 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED; 117 else if (!pld->user_visible) 118 connect_type = USB_PORT_NOT_USED; 119 out: 120 kfree(upc); 121 return connect_type; 122 } 123 124 125 /* 126 * Private to usb-acpi, all the core needs to know is that 127 * port_dev->location is non-zero when it has been set by the firmware. 128 */ 129 #define USB_ACPI_LOCATION_VALID (1 << 31) 130 131 static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent, 132 int raw) 133 { 134 struct acpi_device *adev; 135 136 if (!parent) 137 return NULL; 138 139 list_for_each_entry(adev, &parent->children, node) { 140 if (acpi_device_adr(adev) == raw) 141 return adev; 142 } 143 144 return acpi_find_child_device(parent, raw, false); 145 } 146 147 static struct acpi_device *usb_acpi_find_companion(struct device *dev) 148 { 149 struct usb_device *udev; 150 struct acpi_device *adev; 151 acpi_handle *parent_handle; 152 153 /* 154 * In the ACPI DSDT table, only usb root hub and usb ports are 155 * acpi device nodes. The hierarchy like following. 156 * Device (EHC1) 157 * Device (HUBN) 158 * Device (PR01) 159 * Device (PR11) 160 * Device (PR12) 161 * Device (PR13) 162 * ... 163 * So all binding process is divided into two parts. binding 164 * root hub and usb ports. 165 */ 166 if (is_usb_device(dev)) { 167 udev = to_usb_device(dev); 168 if (udev->parent) 169 return NULL; 170 171 /* root hub is only child (_ADR=0) under its parent, the HC */ 172 adev = ACPI_COMPANION(dev->parent); 173 return acpi_find_child_device(adev, 0, false); 174 } else if (is_usb_port(dev)) { 175 struct usb_port *port_dev = to_usb_port(dev); 176 int port1 = port_dev->portnum; 177 struct acpi_pld_info *pld; 178 acpi_handle *handle; 179 acpi_status status; 180 181 /* Get the struct usb_device point of port's hub */ 182 udev = to_usb_device(dev->parent->parent); 183 184 /* 185 * The root hub ports' parent is the root hub. The non-root-hub 186 * ports' parent is the parent hub port which the hub is 187 * connected to. 188 */ 189 if (!udev->parent) { 190 struct usb_hcd *hcd = bus_to_hcd(udev->bus); 191 int raw; 192 193 raw = usb_hcd_find_raw_port_number(hcd, port1); 194 195 adev = usb_acpi_find_port(ACPI_COMPANION(&udev->dev), 196 raw); 197 198 if (!adev) 199 return NULL; 200 } else { 201 parent_handle = 202 usb_get_hub_port_acpi_handle(udev->parent, 203 udev->portnum); 204 if (!parent_handle) 205 return NULL; 206 207 acpi_bus_get_device(parent_handle, &adev); 208 209 adev = usb_acpi_find_port(adev, port1); 210 211 if (!adev) 212 return NULL; 213 } 214 handle = adev->handle; 215 status = acpi_get_physical_device_location(handle, &pld); 216 if (ACPI_FAILURE(status) || !pld) 217 return adev; 218 219 port_dev->location = USB_ACPI_LOCATION_VALID 220 | pld->group_token << 8 | pld->group_position; 221 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld); 222 ACPI_FREE(pld); 223 224 return adev; 225 } 226 227 return NULL; 228 } 229 230 static bool usb_acpi_bus_match(struct device *dev) 231 { 232 return is_usb_device(dev) || is_usb_port(dev); 233 } 234 235 static struct acpi_bus_type usb_acpi_bus = { 236 .name = "USB", 237 .match = usb_acpi_bus_match, 238 .find_companion = usb_acpi_find_companion, 239 }; 240 241 int usb_acpi_register(void) 242 { 243 return register_acpi_bus_type(&usb_acpi_bus); 244 } 245 246 void usb_acpi_unregister(void) 247 { 248 unregister_acpi_bus_type(&usb_acpi_bus); 249 } 250