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 */
26bool 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(handle: port_handle);
35 else
36 return false;
37}
38EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
39
40#define UUID_USB_CONTROLLER_DSM "ce2ee385-00e6-48cb-9f05-2edb927c4899"
41#define USB_DSM_DISABLE_U1_U2_FOR_PORT 5
42
43/**
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
47 *
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
54 * Arg3: (empty)
55 *
56 * Return 1 if USB3 port is LPM incapable, negative on error, otherwise 0
57 */
58
59int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index)
60{
61 union acpi_object *obj;
62 acpi_handle port_handle;
63 int port1 = index + 1;
64 guid_t guid;
65 int ret;
66
67 ret = guid_parse(UUID_USB_CONTROLLER_DSM, u: &guid);
68 if (ret)
69 return ret;
70
71 port_handle = usb_get_hub_port_acpi_handle(hdev, port1);
72 if (!port_handle) {
73 dev_dbg(&hdev->dev, "port-%d no acpi handle\n", port1);
74 return -ENODEV;
75 }
76
77 if (!acpi_check_dsm(handle: port_handle, guid: &guid, rev: 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);
81 return -ENODEV;
82 }
83
84 obj = acpi_evaluate_dsm_typed(handle: port_handle, guid: &guid, rev: 0,
85 USB_DSM_DISABLE_U1_U2_FOR_PORT, NULL,
86 ACPI_TYPE_INTEGER);
87 if (!obj) {
88 dev_dbg(&hdev->dev, "evaluate port-%d _DSM failed\n", port1);
89 return -EINVAL;
90 }
91
92 if (obj->integer.value == 0x01)
93 ret = 1;
94
95 ACPI_FREE(obj);
96
97 return ret;
98}
99EXPORT_SYMBOL_GPL(usb_acpi_port_lpm_incapable);
100
101/**
102 * usb_acpi_set_power_state - control usb port's power via acpi power
103 * resource
104 * @hdev: USB device belonging to the usb hub
105 * @index: port index based zero
106 * @enable: power state expected to be set
107 *
108 * Notice to use usb_acpi_power_manageable() to check whether the usb port
109 * has acpi power resource before invoking this function.
110 *
111 * Returns 0 on success, else negative errno.
112 */
113int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
114{
115 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
116 struct usb_port *port_dev;
117 acpi_handle port_handle;
118 unsigned char state;
119 int port1 = index + 1;
120 int error = -EINVAL;
121
122 if (!hub)
123 return -ENODEV;
124 port_dev = hub->ports[port1 - 1];
125
126 port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
127 if (!port_handle)
128 return error;
129
130 if (enable)
131 state = ACPI_STATE_D0;
132 else
133 state = ACPI_STATE_D3_COLD;
134
135 error = acpi_bus_set_power(handle: port_handle, state);
136 if (!error)
137 dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
138 else
139 dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
140
141 return error;
142}
143EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
144
145/**
146 * usb_acpi_add_usb4_devlink - add device link to USB4 Host Interface for tunneled USB3 devices
147 *
148 * @udev: Tunneled USB3 device connected to a roothub.
149 *
150 * Adds a device link between a tunneled USB3 device and the USB4 Host Interface
151 * device to ensure correct runtime PM suspend and resume order. This function
152 * should only be called for tunneled USB3 devices.
153 * The USB4 Host Interface this tunneled device depends on is found from the roothub
154 * port ACPI device specific data _DSD entry.
155 *
156 * Return: negative error code on failure, 0 otherwise
157 */
158static int usb_acpi_add_usb4_devlink(struct usb_device *udev)
159{
160 struct device_link *link;
161 struct usb_port *port_dev;
162 struct usb_hub *hub;
163
164 if (!udev->parent || udev->parent->parent)
165 return 0;
166
167 hub = usb_hub_to_struct_hub(hdev: udev->parent);
168 if (!hub)
169 return 0;
170 port_dev = hub->ports[udev->portnum - 1];
171
172 struct fwnode_handle *nhi_fwnode __free(fwnode_handle) =
173 fwnode_find_reference(dev_fwnode(&port_dev->dev), name: "usb4-host-interface", index: 0);
174
175 if (IS_ERR(ptr: nhi_fwnode) || !nhi_fwnode->dev)
176 return 0;
177
178 link = device_link_add(consumer: &port_dev->child->dev, supplier: nhi_fwnode->dev,
179 DL_FLAG_STATELESS |
180 DL_FLAG_RPM_ACTIVE |
181 DL_FLAG_PM_RUNTIME);
182 if (!link) {
183 dev_err(&port_dev->dev, "Failed to created device link from %s to %s\n",
184 dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));
185 return -EINVAL;
186 }
187
188 dev_dbg(&port_dev->dev, "Created device link from %s to %s\n",
189 dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));
190
191 udev->usb4_link = link;
192
193 return 0;
194}
195
196/*
197 * Private to usb-acpi, all the core needs to know is that
198 * port_dev->location is non-zero when it has been set by the firmware.
199 */
200#define USB_ACPI_LOCATION_VALID (1 << 31)
201
202static void
203usb_acpi_get_connect_type(struct usb_port *port_dev, acpi_handle *handle)
204{
205 enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
206 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
207 union acpi_object *upc = NULL;
208 struct acpi_pld_info *pld = NULL;
209 acpi_status status;
210
211 /*
212 * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
213 * is user visible and _UPC indicates whether it is connectable. If
214 * the port was visible and connectable, it could be freely connected
215 * and disconnected with USB devices. If no visible and connectable,
216 * a usb device is directly hard-wired to the port. If no visible and
217 * no connectable, the port would be not used.
218 */
219
220 if (acpi_get_physical_device_location(handle, pld: &pld) && pld)
221 port_dev->location = USB_ACPI_LOCATION_VALID |
222 pld->group_token << 8 | pld->group_position;
223
224 status = acpi_evaluate_object(object: handle, pathname: "_UPC", NULL, return_object_buffer: &buffer);
225 if (ACPI_FAILURE(status))
226 goto out;
227
228 upc = buffer.pointer;
229 if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
230 goto out;
231
232 /* UPC states port is connectable */
233 if (upc->package.elements[0].integer.value)
234 if (!pld)
235 ; /* keep connect_type as unknown */
236 else if (pld->user_visible)
237 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
238 else
239 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
240 else
241 connect_type = USB_PORT_NOT_USED;
242out:
243 port_dev->connect_type = connect_type;
244 kfree(objp: upc);
245 ACPI_FREE(pld);
246}
247
248static struct acpi_device *
249usb_acpi_get_companion_for_port(struct usb_port *port_dev)
250{
251 struct usb_device *udev;
252 struct acpi_device *adev;
253 acpi_handle *parent_handle;
254 int port1;
255
256 /* Get the struct usb_device point of port's hub */
257 udev = to_usb_device(port_dev->dev.parent->parent);
258
259 /*
260 * The root hub ports' parent is the root hub. The non-root-hub
261 * ports' parent is the parent hub port which the hub is
262 * connected to.
263 */
264 if (!udev->parent) {
265 adev = ACPI_COMPANION(&udev->dev);
266 port1 = usb_hcd_find_raw_port_number(hcd: bus_to_hcd(bus: udev->bus),
267 port1: port_dev->portnum);
268 } else {
269 parent_handle = usb_get_hub_port_acpi_handle(hdev: udev->parent,
270 port1: udev->portnum);
271 if (!parent_handle)
272 return NULL;
273
274 adev = acpi_fetch_acpi_dev(handle: parent_handle);
275 port1 = port_dev->portnum;
276 }
277
278 return acpi_find_child_by_adr(adev, adr: port1);
279}
280
281static struct acpi_device *
282usb_acpi_find_companion_for_port(struct usb_port *port_dev)
283{
284 struct acpi_device *adev;
285
286 adev = usb_acpi_get_companion_for_port(port_dev);
287 if (!adev)
288 return NULL;
289
290 usb_acpi_get_connect_type(port_dev, handle: adev->handle);
291
292 return adev;
293}
294
295static struct acpi_device *
296usb_acpi_find_companion_for_device(struct usb_device *udev)
297{
298 struct acpi_device *adev;
299 struct usb_port *port_dev;
300 struct usb_hub *hub;
301
302 if (!udev->parent) {
303 /*
304 * root hub is only child (_ADR=0) under its parent, the HC.
305 * sysdev pointer is the HC as seen from firmware.
306 */
307 adev = ACPI_COMPANION(udev->bus->sysdev);
308 return acpi_find_child_device(parent: adev, address: 0, check_children: false);
309 }
310
311 hub = usb_hub_to_struct_hub(hdev: udev->parent);
312 if (!hub)
313 return NULL;
314
315
316 /* Tunneled USB3 devices depend on USB4 Host Interface, set device link to it */
317 if (udev->speed >= USB_SPEED_SUPER &&
318 udev->tunnel_mode != USB_LINK_NATIVE)
319 usb_acpi_add_usb4_devlink(udev);
320
321 /*
322 * This is an embedded USB device connected to a port and such
323 * devices share port's ACPI companion.
324 */
325 port_dev = hub->ports[udev->portnum - 1];
326 return usb_acpi_get_companion_for_port(port_dev);
327}
328
329static struct acpi_device *usb_acpi_find_companion(struct device *dev)
330{
331 /*
332 * The USB hierarchy like following:
333 *
334 * Device (EHC1)
335 * Device (HUBN)
336 * Device (PR01)
337 * Device (PR11)
338 * Device (PR12)
339 * Device (FN12)
340 * Device (FN13)
341 * Device (PR13)
342 * ...
343 * where HUBN is root hub, and PRNN are USB ports and devices
344 * connected to them, and FNNN are individualk functions for
345 * connected composite USB devices. PRNN and FNNN may contain
346 * _CRS and other methods describing sideband resources for
347 * the connected device.
348 *
349 * On the kernel side both root hub and embedded USB devices are
350 * represented as instances of usb_device structure, and ports
351 * are represented as usb_port structures, so the whole process
352 * is split into 2 parts: finding companions for devices and
353 * finding companions for ports.
354 *
355 * Note that we do not handle individual functions of composite
356 * devices yet, for that we would need to assign companions to
357 * devices corresponding to USB interfaces.
358 */
359 if (is_usb_device(dev))
360 return usb_acpi_find_companion_for_device(to_usb_device(dev));
361 else if (is_usb_port(dev))
362 return usb_acpi_find_companion_for_port(to_usb_port(dev));
363
364 return NULL;
365}
366
367static bool usb_acpi_bus_match(struct device *dev)
368{
369 return is_usb_device(dev) || is_usb_port(dev);
370}
371
372static struct acpi_bus_type usb_acpi_bus = {
373 .name = "USB",
374 .match = usb_acpi_bus_match,
375 .find_companion = usb_acpi_find_companion,
376};
377
378int usb_acpi_register(void)
379{
380 return register_acpi_bus_type(&usb_acpi_bus);
381}
382
383void usb_acpi_unregister(void)
384{
385 unregister_acpi_bus_type(&usb_acpi_bus);
386}
387