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(port_handle, &guid, 0,
85 USB_DSM_DISABLE_U1_U2_FOR_PORT, NULL);
86
87 if (!obj)
88 return -ENODEV;
89
90 if (obj->type != ACPI_TYPE_INTEGER) {
91 dev_dbg(&hdev->dev, "evaluate port-%d _DSM failed\n", port1);
92 ACPI_FREE(obj);
93 return -EINVAL;
94 }
95
96 if (obj->integer.value == 0x01)
97 ret = 1;
98
99 ACPI_FREE(obj);
100
101 return ret;
102 }
103 EXPORT_SYMBOL_GPL(usb_acpi_port_lpm_incapable);
104
105 /**
106 * usb_acpi_set_power_state - control usb port's power via acpi power
107 * resource
108 * @hdev: USB device belonging to the usb hub
109 * @index: port index based zero
110 * @enable: power state expected to be set
111 *
112 * Notice to use usb_acpi_power_manageable() to check whether the usb port
113 * has acpi power resource before invoking this function.
114 *
115 * Returns 0 on success, else negative errno.
116 */
usb_acpi_set_power_state(struct usb_device * hdev,int index,bool enable)117 int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
118 {
119 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
120 struct usb_port *port_dev;
121 acpi_handle port_handle;
122 unsigned char state;
123 int port1 = index + 1;
124 int error = -EINVAL;
125
126 if (!hub)
127 return -ENODEV;
128 port_dev = hub->ports[port1 - 1];
129
130 port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
131 if (!port_handle)
132 return error;
133
134 if (enable)
135 state = ACPI_STATE_D0;
136 else
137 state = ACPI_STATE_D3_COLD;
138
139 error = acpi_bus_set_power(port_handle, state);
140 if (!error)
141 dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
142 else
143 dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
144
145 return error;
146 }
147 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
148
usb_acpi_get_connect_type(acpi_handle handle,struct acpi_pld_info * pld)149 static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
150 struct acpi_pld_info *pld)
151 {
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;
155 acpi_status status;
156
157 /*
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.
164 */
165 status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
166 if (ACPI_FAILURE(status))
167 goto out;
168
169 upc = buffer.pointer;
170 if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
171 goto out;
172
173 if (upc->package.elements[0].integer.value)
174 if (pld->user_visible)
175 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
176 else
177 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
178 else if (!pld->user_visible)
179 connect_type = USB_PORT_NOT_USED;
180 out:
181 kfree(upc);
182 return connect_type;
183 }
184
185
186 /*
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.
189 */
190 #define USB_ACPI_LOCATION_VALID (1 << 31)
191
usb_acpi_find_port(struct acpi_device * parent,int raw)192 static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
193 int raw)
194 {
195 struct acpi_device *adev;
196
197 if (!parent)
198 return NULL;
199
200 list_for_each_entry(adev, &parent->children, node) {
201 if (acpi_device_adr(adev) == raw)
202 return adev;
203 }
204
205 return acpi_find_child_device(parent, raw, false);
206 }
207
208 static struct acpi_device *
usb_acpi_get_companion_for_port(struct usb_port * port_dev)209 usb_acpi_get_companion_for_port(struct usb_port *port_dev)
210 {
211 struct usb_device *udev;
212 struct acpi_device *adev;
213 acpi_handle *parent_handle;
214 int port1;
215
216 /* Get the struct usb_device point of port's hub */
217 udev = to_usb_device(port_dev->dev.parent->parent);
218
219 /*
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
222 * connected to.
223 */
224 if (!udev->parent) {
225 adev = ACPI_COMPANION(&udev->dev);
226 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
227 port_dev->portnum);
228 } else {
229 parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
230 udev->portnum);
231 if (!parent_handle)
232 return NULL;
233
234 acpi_bus_get_device(parent_handle, &adev);
235 port1 = port_dev->portnum;
236 }
237
238 return usb_acpi_find_port(adev, port1);
239 }
240
241 static struct acpi_device *
usb_acpi_find_companion_for_port(struct usb_port * port_dev)242 usb_acpi_find_companion_for_port(struct usb_port *port_dev)
243 {
244 struct acpi_device *adev;
245 struct acpi_pld_info *pld;
246 acpi_handle *handle;
247 acpi_status status;
248
249 adev = usb_acpi_get_companion_for_port(port_dev);
250 if (!adev)
251 return NULL;
252
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);
259 ACPI_FREE(pld);
260 }
261
262 return adev;
263 }
264
265 static struct acpi_device *
usb_acpi_find_companion_for_device(struct usb_device * udev)266 usb_acpi_find_companion_for_device(struct usb_device *udev)
267 {
268 struct acpi_device *adev;
269 struct usb_port *port_dev;
270 struct usb_hub *hub;
271
272 if (!udev->parent) {
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);
276 }
277
278 hub = usb_hub_to_struct_hub(udev->parent);
279 if (!hub)
280 return NULL;
281
282 /*
283 * This is an embedded USB device connected to a port and such
284 * devices share port's ACPI companion.
285 */
286 port_dev = hub->ports[udev->portnum - 1];
287 return usb_acpi_get_companion_for_port(port_dev);
288 }
289
usb_acpi_find_companion(struct device * dev)290 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
291 {
292 /*
293 * The USB hierarchy like following:
294 *
295 * Device (EHC1)
296 * Device (HUBN)
297 * Device (PR01)
298 * Device (PR11)
299 * Device (PR12)
300 * Device (FN12)
301 * Device (FN13)
302 * Device (PR13)
303 * ...
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.
309 *
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.
315 *
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.
319 */
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));
324
325 return NULL;
326 }
327
usb_acpi_bus_match(struct device * dev)328 static bool usb_acpi_bus_match(struct device *dev)
329 {
330 return is_usb_device(dev) || is_usb_port(dev);
331 }
332
333 static struct acpi_bus_type usb_acpi_bus = {
334 .name = "USB",
335 .match = usb_acpi_bus_match,
336 .find_companion = usb_acpi_find_companion,
337 };
338
usb_acpi_register(void)339 int usb_acpi_register(void)
340 {
341 return register_acpi_bus_type(&usb_acpi_bus);
342 }
343
usb_acpi_unregister(void)344 void usb_acpi_unregister(void)
345 {
346 unregister_acpi_bus_type(&usb_acpi_bus);
347 }
348