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 *usb_acpi_find_companion(struct device *dev) 143 { 144 struct usb_device *udev; 145 struct acpi_device *adev; 146 acpi_handle *parent_handle; 147 148 /* 149 * In the ACPI DSDT table, only usb root hub and usb ports are 150 * acpi device nodes. The hierarchy like following. 151 * Device (EHC1) 152 * Device (HUBN) 153 * Device (PR01) 154 * Device (PR11) 155 * Device (PR12) 156 * Device (PR13) 157 * ... 158 * So all binding process is divided into two parts. binding 159 * root hub and usb ports. 160 */ 161 if (is_usb_device(dev)) { 162 udev = to_usb_device(dev); 163 if (udev->parent) 164 return NULL; 165 166 /* root hub is only child (_ADR=0) under its parent, the HC */ 167 adev = ACPI_COMPANION(dev->parent); 168 return acpi_find_child_device(adev, 0, false); 169 } else if (is_usb_port(dev)) { 170 struct usb_port *port_dev = to_usb_port(dev); 171 int port1 = port_dev->portnum; 172 struct acpi_pld_info *pld; 173 acpi_handle *handle; 174 acpi_status status; 175 176 /* Get the struct usb_device point of port's hub */ 177 udev = to_usb_device(dev->parent->parent); 178 179 /* 180 * The root hub ports' parent is the root hub. The non-root-hub 181 * ports' parent is the parent hub port which the hub is 182 * connected to. 183 */ 184 if (!udev->parent) { 185 struct usb_hcd *hcd = bus_to_hcd(udev->bus); 186 int raw; 187 188 raw = usb_hcd_find_raw_port_number(hcd, port1); 189 190 adev = usb_acpi_find_port(ACPI_COMPANION(&udev->dev), 191 raw); 192 193 if (!adev) 194 return NULL; 195 } else { 196 parent_handle = 197 usb_get_hub_port_acpi_handle(udev->parent, 198 udev->portnum); 199 if (!parent_handle) 200 return NULL; 201 202 acpi_bus_get_device(parent_handle, &adev); 203 204 adev = usb_acpi_find_port(adev, port1); 205 206 if (!adev) 207 return NULL; 208 } 209 handle = adev->handle; 210 status = acpi_get_physical_device_location(handle, &pld); 211 if (ACPI_FAILURE(status) || !pld) 212 return adev; 213 214 port_dev->location = USB_ACPI_LOCATION_VALID 215 | pld->group_token << 8 | pld->group_position; 216 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld); 217 ACPI_FREE(pld); 218 219 return adev; 220 } 221 222 return NULL; 223 } 224 225 static bool usb_acpi_bus_match(struct device *dev) 226 { 227 return is_usb_device(dev) || is_usb_port(dev); 228 } 229 230 static struct acpi_bus_type usb_acpi_bus = { 231 .name = "USB", 232 .match = usb_acpi_bus_match, 233 .find_companion = usb_acpi_find_companion, 234 }; 235 236 int usb_acpi_register(void) 237 { 238 return register_acpi_bus_type(&usb_acpi_bus); 239 } 240 241 void usb_acpi_unregister(void) 242 { 243 unregister_acpi_bus_type(&usb_acpi_bus); 244 } 245