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 "usb.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 acpi_handle port_handle; 59 unsigned char state; 60 int port1 = index + 1; 61 int error = -EINVAL; 62 63 port_handle = (acpi_handle)usb_get_hub_port_acpi_handle(hdev, 64 port1); 65 if (!port_handle) 66 return error; 67 68 if (enable) 69 state = ACPI_STATE_D0; 70 else 71 state = ACPI_STATE_D3_COLD; 72 73 error = acpi_bus_set_power(port_handle, state); 74 if (!error) 75 dev_dbg(&hdev->dev, "The power of hub port %d was set to %d\n", 76 port1, enable); 77 else 78 dev_dbg(&hdev->dev, "The power of hub port failed to be set\n"); 79 80 return error; 81 } 82 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state); 83 84 static int usb_acpi_check_port_connect_type(struct usb_device *hdev, 85 acpi_handle handle, int port1) 86 { 87 acpi_status status; 88 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 89 union acpi_object *upc; 90 struct acpi_pld_info *pld; 91 int ret = 0; 92 93 /* 94 * According to ACPI Spec 9.13. PLD indicates whether usb port is 95 * user visible and _UPC indicates whether it is connectable. If 96 * the port was visible and connectable, it could be freely connected 97 * and disconnected with USB devices. If no visible and connectable, 98 * a usb device is directly hard-wired to the port. If no visible and 99 * no connectable, the port would be not used. 100 */ 101 status = acpi_get_physical_device_location(handle, &pld); 102 if (ACPI_FAILURE(status)) 103 return -ENODEV; 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 ret = -EINVAL; 110 goto out; 111 } 112 113 if (upc->package.elements[0].integer.value) 114 if (pld->user_visible) 115 usb_set_hub_port_connect_type(hdev, port1, 116 USB_PORT_CONNECT_TYPE_HOT_PLUG); 117 else 118 usb_set_hub_port_connect_type(hdev, port1, 119 USB_PORT_CONNECT_TYPE_HARD_WIRED); 120 else if (!pld->user_visible) 121 usb_set_hub_port_connect_type(hdev, port1, USB_PORT_NOT_USED); 122 123 out: 124 ACPI_FREE(pld); 125 kfree(upc); 126 return ret; 127 } 128 129 static struct acpi_device *usb_acpi_find_companion(struct device *dev) 130 { 131 struct usb_device *udev; 132 acpi_handle *parent_handle; 133 int port_num; 134 135 /* 136 * In the ACPI DSDT table, only usb root hub and usb ports are 137 * acpi device nodes. The hierarchy like following. 138 * Device (EHC1) 139 * Device (HUBN) 140 * Device (PR01) 141 * Device (PR11) 142 * Device (PR12) 143 * Device (PR13) 144 * ... 145 * So all binding process is divided into two parts. binding 146 * root hub and usb ports. 147 */ 148 if (is_usb_device(dev)) { 149 udev = to_usb_device(dev); 150 if (udev->parent) { 151 enum usb_port_connect_type type; 152 153 /* 154 * According usb port's connect type to set usb device's 155 * removability. 156 */ 157 type = usb_get_hub_port_connect_type(udev->parent, 158 udev->portnum); 159 switch (type) { 160 case USB_PORT_CONNECT_TYPE_HOT_PLUG: 161 udev->removable = USB_DEVICE_REMOVABLE; 162 break; 163 case USB_PORT_CONNECT_TYPE_HARD_WIRED: 164 udev->removable = USB_DEVICE_FIXED; 165 break; 166 default: 167 udev->removable = USB_DEVICE_REMOVABLE_UNKNOWN; 168 break; 169 } 170 171 return NULL; 172 } 173 174 /* root hub's parent is the usb hcd. */ 175 return acpi_find_child_device(ACPI_COMPANION(dev->parent), 176 udev->portnum, false); 177 } else if (is_usb_port(dev)) { 178 struct acpi_device *adev = NULL; 179 180 sscanf(dev_name(dev), "port%d", &port_num); 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_port_num; 192 193 raw_port_num = usb_hcd_find_raw_port_number(hcd, 194 port_num); 195 adev = acpi_find_child_device(ACPI_COMPANION(&udev->dev), 196 raw_port_num, false); 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 adev = acpi_find_child_device(adev, port_num, false); 208 if (!adev) 209 return NULL; 210 } 211 usb_acpi_check_port_connect_type(udev, adev->handle, port_num); 212 return adev; 213 } 214 215 return NULL; 216 } 217 218 static bool usb_acpi_bus_match(struct device *dev) 219 { 220 return is_usb_device(dev) || is_usb_port(dev); 221 } 222 223 static struct acpi_bus_type usb_acpi_bus = { 224 .name = "USB", 225 .match = usb_acpi_bus_match, 226 .find_companion = usb_acpi_find_companion, 227 }; 228 229 int usb_acpi_register(void) 230 { 231 return register_acpi_bus_type(&usb_acpi_bus); 232 } 233 234 void usb_acpi_unregister(void) 235 { 236 unregister_acpi_bus_type(&usb_acpi_bus); 237 } 238