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(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, &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}
103EXPORT_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 */
117int 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}
147EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
148
149static 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;
180out:
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
192static 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
208static struct acpi_device *
209usb_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
241static struct acpi_device *
242usb_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
265static struct acpi_device *
266usb_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
290static 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
328static bool usb_acpi_bus_match(struct device *dev)
329{
330	return is_usb_device(dev) || is_usb_port(dev);
331}
332
333static 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
339int usb_acpi_register(void)
340{
341	return register_acpi_bus_type(&usb_acpi_bus);
342}
343
344void usb_acpi_unregister(void)
345{
346	unregister_acpi_bus_type(&usb_acpi_bus);
347}
348