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
usb_acpi_get_connect_type(acpi_handle handle,struct acpi_pld_info * pld)145 static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
146 struct acpi_pld_info *pld)
147 {
148 enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
149 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
150 union acpi_object *upc = NULL;
151 acpi_status status;
152
153 /*
154 * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
155 * is user visible and _UPC indicates whether it is connectable. If
156 * the port was visible and connectable, it could be freely connected
157 * and disconnected with USB devices. If no visible and connectable,
158 * a usb device is directly hard-wired to the port. If no visible and
159 * no connectable, the port would be not used.
160 */
161 status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
162 if (ACPI_FAILURE(status))
163 goto out;
164
165 upc = buffer.pointer;
166 if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
167 goto out;
168
169 if (upc->package.elements[0].integer.value)
170 if (pld->user_visible)
171 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
172 else
173 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
174 else if (!pld->user_visible)
175 connect_type = USB_PORT_NOT_USED;
176 out:
177 kfree(upc);
178 return connect_type;
179 }
180
181
182 /*
183 * Private to usb-acpi, all the core needs to know is that
184 * port_dev->location is non-zero when it has been set by the firmware.
185 */
186 #define USB_ACPI_LOCATION_VALID (1 << 31)
187
188 static struct acpi_device *
usb_acpi_get_companion_for_port(struct usb_port * port_dev)189 usb_acpi_get_companion_for_port(struct usb_port *port_dev)
190 {
191 struct usb_device *udev;
192 struct acpi_device *adev;
193 acpi_handle *parent_handle;
194 int port1;
195
196 /* Get the struct usb_device point of port's hub */
197 udev = to_usb_device(port_dev->dev.parent->parent);
198
199 /*
200 * The root hub ports' parent is the root hub. The non-root-hub
201 * ports' parent is the parent hub port which the hub is
202 * connected to.
203 */
204 if (!udev->parent) {
205 adev = ACPI_COMPANION(&udev->dev);
206 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
207 port_dev->portnum);
208 } else {
209 parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
210 udev->portnum);
211 if (!parent_handle)
212 return NULL;
213
214 adev = acpi_fetch_acpi_dev(parent_handle);
215 port1 = port_dev->portnum;
216 }
217
218 return acpi_find_child_by_adr(adev, port1);
219 }
220
221 static struct acpi_device *
usb_acpi_find_companion_for_port(struct usb_port * port_dev)222 usb_acpi_find_companion_for_port(struct usb_port *port_dev)
223 {
224 struct acpi_device *adev;
225 struct acpi_pld_info *pld;
226 acpi_handle *handle;
227 acpi_status status;
228
229 adev = usb_acpi_get_companion_for_port(port_dev);
230 if (!adev)
231 return NULL;
232
233 handle = adev->handle;
234 status = acpi_get_physical_device_location(handle, &pld);
235 if (ACPI_SUCCESS(status) && pld) {
236 port_dev->location = USB_ACPI_LOCATION_VALID
237 | pld->group_token << 8 | pld->group_position;
238 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
239 ACPI_FREE(pld);
240 }
241
242 return adev;
243 }
244
245 static struct acpi_device *
usb_acpi_find_companion_for_device(struct usb_device * udev)246 usb_acpi_find_companion_for_device(struct usb_device *udev)
247 {
248 struct acpi_device *adev;
249 struct usb_port *port_dev;
250 struct usb_hub *hub;
251
252 if (!udev->parent) {
253 /*
254 * root hub is only child (_ADR=0) under its parent, the HC.
255 * sysdev pointer is the HC as seen from firmware.
256 */
257 adev = ACPI_COMPANION(udev->bus->sysdev);
258 return acpi_find_child_device(adev, 0, false);
259 }
260
261 hub = usb_hub_to_struct_hub(udev->parent);
262 if (!hub)
263 return NULL;
264
265 /*
266 * This is an embedded USB device connected to a port and such
267 * devices share port's ACPI companion.
268 */
269 port_dev = hub->ports[udev->portnum - 1];
270 return usb_acpi_get_companion_for_port(port_dev);
271 }
272
usb_acpi_find_companion(struct device * dev)273 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
274 {
275 /*
276 * The USB hierarchy like following:
277 *
278 * Device (EHC1)
279 * Device (HUBN)
280 * Device (PR01)
281 * Device (PR11)
282 * Device (PR12)
283 * Device (FN12)
284 * Device (FN13)
285 * Device (PR13)
286 * ...
287 * where HUBN is root hub, and PRNN are USB ports and devices
288 * connected to them, and FNNN are individualk functions for
289 * connected composite USB devices. PRNN and FNNN may contain
290 * _CRS and other methods describing sideband resources for
291 * the connected device.
292 *
293 * On the kernel side both root hub and embedded USB devices are
294 * represented as instances of usb_device structure, and ports
295 * are represented as usb_port structures, so the whole process
296 * is split into 2 parts: finding companions for devices and
297 * finding companions for ports.
298 *
299 * Note that we do not handle individual functions of composite
300 * devices yet, for that we would need to assign companions to
301 * devices corresponding to USB interfaces.
302 */
303 if (is_usb_device(dev))
304 return usb_acpi_find_companion_for_device(to_usb_device(dev));
305 else if (is_usb_port(dev))
306 return usb_acpi_find_companion_for_port(to_usb_port(dev));
307
308 return NULL;
309 }
310
usb_acpi_bus_match(struct device * dev)311 static bool usb_acpi_bus_match(struct device *dev)
312 {
313 return is_usb_device(dev) || is_usb_port(dev);
314 }
315
316 static struct acpi_bus_type usb_acpi_bus = {
317 .name = "USB",
318 .match = usb_acpi_bus_match,
319 .find_companion = usb_acpi_find_companion,
320 };
321
usb_acpi_register(void)322 int usb_acpi_register(void)
323 {
324 return register_acpi_bus_type(&usb_acpi_bus);
325 }
326
usb_acpi_unregister(void)327 void usb_acpi_unregister(void)
328 {
329 unregister_acpi_bus_type(&usb_acpi_bus);
330 }
331