1 // SPDX-License-Identifier: GPL-2.0
5 * Copyright 2012 Red Hat <mjg@redhat.com>
7 #include <linux/module.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>
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
24 * Return true if the port has acpi power resource and false if no.
26 bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
28 acpi_handle port_handle;
29 int port1 = index + 1;
31 port_handle = usb_get_hub_port_acpi_handle(hdev,
34 return acpi_bus_power_manageable(port_handle);
38 EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
40 #define UUID_USB_CONTROLLER_DSM "ce2ee385-00e6-48cb-9f05-2edb927c4899"
41 #define USB_DSM_DISABLE_U1_U2_FOR_PORT 5
44 * usb_acpi_port_lpm_incapable - check if lpm should be disabled for a port.
45 * @hdev: USB device belonging to the usb hub
46 * @index: zero based port index
48 * Some USB3 ports may not support USB3 link power management U1/U2 states
49 * due to different retimer setup. ACPI provides _DSM method which returns 0x01
50 * if U1 and U2 states should be disabled. Evaluate _DSM with:
51 * Arg0: UUID = ce2ee385-00e6-48cb-9f05-2edb927c4899
52 * Arg1: Revision ID = 0
53 * Arg2: Function Index = 5
56 * Return 1 if USB3 port is LPM incapable, negative on error, otherwise 0
59 int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index)
61 union acpi_object *obj;
62 acpi_handle port_handle;
63 int port1 = index + 1;
67 ret = guid_parse(UUID_USB_CONTROLLER_DSM, &guid);
71 port_handle = usb_get_hub_port_acpi_handle(hdev, port1);
73 dev_dbg(&hdev->dev, "port-%d no acpi handle\n", port1);
77 if (!acpi_check_dsm(port_handle, &guid, 0,
78 BIT(USB_DSM_DISABLE_U1_U2_FOR_PORT))) {
79 dev_dbg(&hdev->dev, "port-%d no _DSM function %d\n",
80 port1, USB_DSM_DISABLE_U1_U2_FOR_PORT);
84 obj = acpi_evaluate_dsm(port_handle, &guid, 0,
85 USB_DSM_DISABLE_U1_U2_FOR_PORT, NULL);
90 if (obj->type != ACPI_TYPE_INTEGER) {
91 dev_dbg(&hdev->dev, "evaluate port-%d _DSM failed\n", port1);
96 if (obj->integer.value == 0x01)
103 EXPORT_SYMBOL_GPL(usb_acpi_port_lpm_incapable);
106 * usb_acpi_set_power_state - control usb port's power via acpi power
108 * @hdev: USB device belonging to the usb hub
109 * @index: port index based zero
110 * @enable: power state expected to be set
112 * Notice to use usb_acpi_power_manageable() to check whether the usb port
113 * has acpi power resource before invoking this function.
115 * Returns 0 on success, else negative errno.
117 int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
119 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
120 struct usb_port *port_dev;
121 acpi_handle port_handle;
123 int port1 = index + 1;
128 port_dev = hub->ports[port1 - 1];
130 port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
135 state = ACPI_STATE_D0;
137 state = ACPI_STATE_D3_COLD;
139 error = acpi_bus_set_power(port_handle, state);
141 dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
143 dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
147 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
149 static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
150 struct acpi_pld_info *pld)
152 enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
153 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
154 union acpi_object *upc = NULL;
158 * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
159 * is user visible and _UPC indicates whether it is connectable. If
160 * the port was visible and connectable, it could be freely connected
161 * and disconnected with USB devices. If no visible and connectable,
162 * a usb device is directly hard-wired to the port. If no visible and
163 * no connectable, the port would be not used.
165 status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
166 if (ACPI_FAILURE(status))
169 upc = buffer.pointer;
170 if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
173 if (upc->package.elements[0].integer.value)
174 if (pld->user_visible)
175 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
177 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
178 else if (!pld->user_visible)
179 connect_type = USB_PORT_NOT_USED;
187 * Private to usb-acpi, all the core needs to know is that
188 * port_dev->location is non-zero when it has been set by the firmware.
190 #define USB_ACPI_LOCATION_VALID (1 << 31)
192 static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
195 struct acpi_device *adev;
200 list_for_each_entry(adev, &parent->children, node) {
201 if (acpi_device_adr(adev) == raw)
205 return acpi_find_child_device(parent, raw, false);
208 static struct acpi_device *
209 usb_acpi_get_companion_for_port(struct usb_port *port_dev)
211 struct usb_device *udev;
212 struct acpi_device *adev;
213 acpi_handle *parent_handle;
216 /* Get the struct usb_device point of port's hub */
217 udev = to_usb_device(port_dev->dev.parent->parent);
220 * The root hub ports' parent is the root hub. The non-root-hub
221 * ports' parent is the parent hub port which the hub is
225 adev = ACPI_COMPANION(&udev->dev);
226 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
229 parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
234 acpi_bus_get_device(parent_handle, &adev);
235 port1 = port_dev->portnum;
238 return usb_acpi_find_port(adev, port1);
241 static struct acpi_device *
242 usb_acpi_find_companion_for_port(struct usb_port *port_dev)
244 struct acpi_device *adev;
245 struct acpi_pld_info *pld;
249 adev = usb_acpi_get_companion_for_port(port_dev);
253 handle = adev->handle;
254 status = acpi_get_physical_device_location(handle, &pld);
255 if (ACPI_SUCCESS(status) && pld) {
256 port_dev->location = USB_ACPI_LOCATION_VALID
257 | pld->group_token << 8 | pld->group_position;
258 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
265 static struct acpi_device *
266 usb_acpi_find_companion_for_device(struct usb_device *udev)
268 struct acpi_device *adev;
269 struct usb_port *port_dev;
273 /* root hub is only child (_ADR=0) under its parent, the HC */
274 adev = ACPI_COMPANION(udev->dev.parent);
275 return acpi_find_child_device(adev, 0, false);
278 hub = usb_hub_to_struct_hub(udev->parent);
283 * This is an embedded USB device connected to a port and such
284 * devices share port's ACPI companion.
286 port_dev = hub->ports[udev->portnum - 1];
287 return usb_acpi_get_companion_for_port(port_dev);
290 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
293 * The USB hierarchy like following:
304 * where HUBN is root hub, and PRNN are USB ports and devices
305 * connected to them, and FNNN are individualk functions for
306 * connected composite USB devices. PRNN and FNNN may contain
307 * _CRS and other methods describing sideband resources for
308 * the connected device.
310 * On the kernel side both root hub and embedded USB devices are
311 * represented as instances of usb_device structure, and ports
312 * are represented as usb_port structures, so the whole process
313 * is split into 2 parts: finding companions for devices and
314 * finding companions for ports.
316 * Note that we do not handle individual functions of composite
317 * devices yet, for that we would need to assign companions to
318 * devices corresponding to USB interfaces.
320 if (is_usb_device(dev))
321 return usb_acpi_find_companion_for_device(to_usb_device(dev));
322 else if (is_usb_port(dev))
323 return usb_acpi_find_companion_for_port(to_usb_port(dev));
328 static bool usb_acpi_bus_match(struct device *dev)
330 return is_usb_device(dev) || is_usb_port(dev);
333 static struct acpi_bus_type usb_acpi_bus = {
335 .match = usb_acpi_bus_match,
336 .find_companion = usb_acpi_find_companion,
339 int usb_acpi_register(void)
341 return register_acpi_bus_type(&usb_acpi_bus);
344 void usb_acpi_unregister(void)
346 unregister_acpi_bus_type(&usb_acpi_bus);