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