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 port_dev = hub->ports[udev->portnum - 1];
169
170 struct fwnode_handle *nhi_fwnode __free(fwnode_handle) =
171 fwnode_find_reference(dev_fwnode(&port_dev->dev), "usb4-host-interface", 0);
172
173 if (IS_ERR(nhi_fwnode) || !nhi_fwnode->dev)
174 return 0;
175
176 link = device_link_add(&port_dev->child->dev, nhi_fwnode->dev,
177 DL_FLAG_STATELESS |
178 DL_FLAG_RPM_ACTIVE |
179 DL_FLAG_PM_RUNTIME);
180 if (!link) {
181 dev_err(&port_dev->dev, "Failed to created device link from %s to %s\n",
182 dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));
183 return -EINVAL;
184 }
185
186 dev_dbg(&port_dev->dev, "Created device link from %s to %s\n",
187 dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));
188
189 return 0;
190 }
191
192 /*
193 * Private to usb-acpi, all the core needs to know is that
194 * port_dev->location is non-zero when it has been set by the firmware.
195 */
196 #define USB_ACPI_LOCATION_VALID (1 << 31)
197
198 static void
usb_acpi_get_connect_type(struct usb_port * port_dev,acpi_handle * handle)199 usb_acpi_get_connect_type(struct usb_port *port_dev, acpi_handle *handle)
200 {
201 enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
202 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
203 union acpi_object *upc = NULL;
204 struct acpi_pld_info *pld = NULL;
205 acpi_status status;
206
207 /*
208 * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
209 * is user visible and _UPC indicates whether it is connectable. If
210 * the port was visible and connectable, it could be freely connected
211 * and disconnected with USB devices. If no visible and connectable,
212 * a usb device is directly hard-wired to the port. If no visible and
213 * no connectable, the port would be not used.
214 */
215
216 status = acpi_get_physical_device_location(handle, &pld);
217 if (ACPI_SUCCESS(status) && pld)
218 port_dev->location = USB_ACPI_LOCATION_VALID |
219 pld->group_token << 8 | pld->group_position;
220
221 status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
222 if (ACPI_FAILURE(status))
223 goto out;
224
225 upc = buffer.pointer;
226 if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
227 goto out;
228
229 /* UPC states port is connectable */
230 if (upc->package.elements[0].integer.value)
231 if (!pld)
232 ; /* keep connect_type as unknown */
233 else if (pld->user_visible)
234 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
235 else
236 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
237 else
238 connect_type = USB_PORT_NOT_USED;
239 out:
240 port_dev->connect_type = connect_type;
241 kfree(upc);
242 ACPI_FREE(pld);
243 }
244
245 static struct acpi_device *
usb_acpi_get_companion_for_port(struct usb_port * port_dev)246 usb_acpi_get_companion_for_port(struct usb_port *port_dev)
247 {
248 struct usb_device *udev;
249 struct acpi_device *adev;
250 acpi_handle *parent_handle;
251 int port1;
252
253 /* Get the struct usb_device point of port's hub */
254 udev = to_usb_device(port_dev->dev.parent->parent);
255
256 /*
257 * The root hub ports' parent is the root hub. The non-root-hub
258 * ports' parent is the parent hub port which the hub is
259 * connected to.
260 */
261 if (!udev->parent) {
262 adev = ACPI_COMPANION(&udev->dev);
263 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
264 port_dev->portnum);
265 } else {
266 parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
267 udev->portnum);
268 if (!parent_handle)
269 return NULL;
270
271 adev = acpi_fetch_acpi_dev(parent_handle);
272 port1 = port_dev->portnum;
273 }
274
275 return acpi_find_child_by_adr(adev, port1);
276 }
277
278 static struct acpi_device *
usb_acpi_find_companion_for_port(struct usb_port * port_dev)279 usb_acpi_find_companion_for_port(struct usb_port *port_dev)
280 {
281 struct acpi_device *adev;
282
283 adev = usb_acpi_get_companion_for_port(port_dev);
284 if (!adev)
285 return NULL;
286
287 usb_acpi_get_connect_type(port_dev, adev->handle);
288
289 return adev;
290 }
291
292 static struct acpi_device *
usb_acpi_find_companion_for_device(struct usb_device * udev)293 usb_acpi_find_companion_for_device(struct usb_device *udev)
294 {
295 struct acpi_device *adev;
296 struct usb_port *port_dev;
297 struct usb_hub *hub;
298
299 if (!udev->parent) {
300 /*
301 * root hub is only child (_ADR=0) under its parent, the HC.
302 * sysdev pointer is the HC as seen from firmware.
303 */
304 adev = ACPI_COMPANION(udev->bus->sysdev);
305 return acpi_find_child_device(adev, 0, false);
306 }
307
308 hub = usb_hub_to_struct_hub(udev->parent);
309 if (!hub)
310 return NULL;
311
312
313 /* Tunneled USB3 devices depend on USB4 Host Interface, set device link to it */
314 if (udev->speed >= USB_SPEED_SUPER &&
315 udev->tunnel_mode != USB_LINK_NATIVE)
316 usb_acpi_add_usb4_devlink(udev);
317
318 /*
319 * This is an embedded USB device connected to a port and such
320 * devices share port's ACPI companion.
321 */
322 port_dev = hub->ports[udev->portnum - 1];
323 return usb_acpi_get_companion_for_port(port_dev);
324 }
325
usb_acpi_find_companion(struct device * dev)326 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
327 {
328 /*
329 * The USB hierarchy like following:
330 *
331 * Device (EHC1)
332 * Device (HUBN)
333 * Device (PR01)
334 * Device (PR11)
335 * Device (PR12)
336 * Device (FN12)
337 * Device (FN13)
338 * Device (PR13)
339 * ...
340 * where HUBN is root hub, and PRNN are USB ports and devices
341 * connected to them, and FNNN are individualk functions for
342 * connected composite USB devices. PRNN and FNNN may contain
343 * _CRS and other methods describing sideband resources for
344 * the connected device.
345 *
346 * On the kernel side both root hub and embedded USB devices are
347 * represented as instances of usb_device structure, and ports
348 * are represented as usb_port structures, so the whole process
349 * is split into 2 parts: finding companions for devices and
350 * finding companions for ports.
351 *
352 * Note that we do not handle individual functions of composite
353 * devices yet, for that we would need to assign companions to
354 * devices corresponding to USB interfaces.
355 */
356 if (is_usb_device(dev))
357 return usb_acpi_find_companion_for_device(to_usb_device(dev));
358 else if (is_usb_port(dev))
359 return usb_acpi_find_companion_for_port(to_usb_port(dev));
360
361 return NULL;
362 }
363
usb_acpi_bus_match(struct device * dev)364 static bool usb_acpi_bus_match(struct device *dev)
365 {
366 return is_usb_device(dev) || is_usb_port(dev);
367 }
368
369 static struct acpi_bus_type usb_acpi_bus = {
370 .name = "USB",
371 .match = usb_acpi_bus_match,
372 .find_companion = usb_acpi_find_companion,
373 };
374
usb_acpi_register(void)375 int usb_acpi_register(void)
376 {
377 return register_acpi_bus_type(&usb_acpi_bus);
378 }
379
usb_acpi_unregister(void)380 void usb_acpi_unregister(void)
381 {
382 unregister_acpi_bus_type(&usb_acpi_bus);
383 }
384