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 */
usb_acpi_power_manageable(struct usb_device * hdev,int index)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 #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
usb_acpi_port_lpm_incapable(struct usb_device * hdev,int index)59 int 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, &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(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);
81 return -ENODEV;
82 }
83
84 obj = acpi_evaluate_dsm_typed(port_handle, &guid, 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 }
99 EXPORT_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 */
usb_acpi_set_power_state(struct usb_device * hdev,int index,bool enable)113 int 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(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 }
143 EXPORT_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 */
usb_acpi_add_usb4_devlink(struct usb_device * udev)158 static int usb_acpi_add_usb4_devlink(struct usb_device *udev)
159 {
160 const 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(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), "usb4-host-interface", 0);
174
175 if (IS_ERR(nhi_fwnode) || !nhi_fwnode->dev)
176 return 0;
177
178 link = device_link_add(&port_dev->child->dev, 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 return 0;
192 }
193
194 /*
195 * Private to usb-acpi, all the core needs to know is that
196 * port_dev->location is non-zero when it has been set by the firmware.
197 */
198 #define USB_ACPI_LOCATION_VALID (1 << 31)
199
200 static void
usb_acpi_get_connect_type(struct usb_port * port_dev,acpi_handle * handle)201 usb_acpi_get_connect_type(struct usb_port *port_dev, acpi_handle *handle)
202 {
203 enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
204 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
205 union acpi_object *upc = NULL;
206 struct acpi_pld_info *pld = NULL;
207 acpi_status status;
208
209 /*
210 * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
211 * is user visible and _UPC indicates whether it is connectable. If
212 * the port was visible and connectable, it could be freely connected
213 * and disconnected with USB devices. If no visible and connectable,
214 * a usb device is directly hard-wired to the port. If no visible and
215 * no connectable, the port would be not used.
216 */
217
218 if (acpi_get_physical_device_location(handle, &pld) && pld)
219 port_dev->location = USB_ACPI_LOCATION_VALID |
220 pld->group_token << 8 | pld->group_position;
221
222 status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
223 if (ACPI_FAILURE(status))
224 goto out;
225
226 upc = buffer.pointer;
227 if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
228 goto out;
229
230 /* UPC states port is connectable */
231 if (upc->package.elements[0].integer.value)
232 if (!pld)
233 ; /* keep connect_type as unknown */
234 else if (pld->user_visible)
235 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
236 else
237 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
238 else
239 connect_type = USB_PORT_NOT_USED;
240 out:
241 port_dev->connect_type = connect_type;
242 kfree(upc);
243 ACPI_FREE(pld);
244 }
245
246 static struct acpi_device *
usb_acpi_get_companion_for_port(struct usb_port * port_dev)247 usb_acpi_get_companion_for_port(struct usb_port *port_dev)
248 {
249 struct usb_device *udev;
250 struct acpi_device *adev;
251 acpi_handle *parent_handle;
252 int port1;
253
254 /* Get the struct usb_device point of port's hub */
255 udev = to_usb_device(port_dev->dev.parent->parent);
256
257 /*
258 * The root hub ports' parent is the root hub. The non-root-hub
259 * ports' parent is the parent hub port which the hub is
260 * connected to.
261 */
262 if (!udev->parent) {
263 adev = ACPI_COMPANION(&udev->dev);
264 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
265 port_dev->portnum);
266 } else {
267 parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
268 udev->portnum);
269 if (!parent_handle)
270 return NULL;
271
272 adev = acpi_fetch_acpi_dev(parent_handle);
273 port1 = port_dev->portnum;
274 }
275
276 return acpi_find_child_by_adr(adev, port1);
277 }
278
279 static struct acpi_device *
usb_acpi_find_companion_for_port(struct usb_port * port_dev)280 usb_acpi_find_companion_for_port(struct usb_port *port_dev)
281 {
282 struct acpi_device *adev;
283
284 adev = usb_acpi_get_companion_for_port(port_dev);
285 if (!adev)
286 return NULL;
287
288 usb_acpi_get_connect_type(port_dev, adev->handle);
289
290 return adev;
291 }
292
293 static struct acpi_device *
usb_acpi_find_companion_for_device(struct usb_device * udev)294 usb_acpi_find_companion_for_device(struct usb_device *udev)
295 {
296 struct acpi_device *adev;
297 struct usb_port *port_dev;
298 struct usb_hub *hub;
299
300 if (!udev->parent) {
301 /*
302 * root hub is only child (_ADR=0) under its parent, the HC.
303 * sysdev pointer is the HC as seen from firmware.
304 */
305 adev = ACPI_COMPANION(udev->bus->sysdev);
306 return acpi_find_child_device(adev, 0, false);
307 }
308
309 hub = usb_hub_to_struct_hub(udev->parent);
310 if (!hub)
311 return NULL;
312
313
314 /* Tunneled USB3 devices depend on USB4 Host Interface, set device link to it */
315 if (udev->speed >= USB_SPEED_SUPER &&
316 udev->tunnel_mode != USB_LINK_NATIVE)
317 usb_acpi_add_usb4_devlink(udev);
318
319 /*
320 * This is an embedded USB device connected to a port and such
321 * devices share port's ACPI companion.
322 */
323 port_dev = hub->ports[udev->portnum - 1];
324 return usb_acpi_get_companion_for_port(port_dev);
325 }
326
usb_acpi_find_companion(struct device * dev)327 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
328 {
329 /*
330 * The USB hierarchy like following:
331 *
332 * Device (EHC1)
333 * Device (HUBN)
334 * Device (PR01)
335 * Device (PR11)
336 * Device (PR12)
337 * Device (FN12)
338 * Device (FN13)
339 * Device (PR13)
340 * ...
341 * where HUBN is root hub, and PRNN are USB ports and devices
342 * connected to them, and FNNN are individualk functions for
343 * connected composite USB devices. PRNN and FNNN may contain
344 * _CRS and other methods describing sideband resources for
345 * the connected device.
346 *
347 * On the kernel side both root hub and embedded USB devices are
348 * represented as instances of usb_device structure, and ports
349 * are represented as usb_port structures, so the whole process
350 * is split into 2 parts: finding companions for devices and
351 * finding companions for ports.
352 *
353 * Note that we do not handle individual functions of composite
354 * devices yet, for that we would need to assign companions to
355 * devices corresponding to USB interfaces.
356 */
357 if (is_usb_device(dev))
358 return usb_acpi_find_companion_for_device(to_usb_device(dev));
359 else if (is_usb_port(dev))
360 return usb_acpi_find_companion_for_port(to_usb_port(dev));
361
362 return NULL;
363 }
364
usb_acpi_bus_match(struct device * dev)365 static bool usb_acpi_bus_match(struct device *dev)
366 {
367 return is_usb_device(dev) || is_usb_port(dev);
368 }
369
370 static struct acpi_bus_type usb_acpi_bus = {
371 .name = "USB",
372 .match = usb_acpi_bus_match,
373 .find_companion = usb_acpi_find_companion,
374 };
375
usb_acpi_register(void)376 int usb_acpi_register(void)
377 {
378 return register_acpi_bus_type(&usb_acpi_bus);
379 }
380
usb_acpi_unregister(void)381 void usb_acpi_unregister(void)
382 {
383 unregister_acpi_bus_type(&usb_acpi_bus);
384 }
385