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_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}
 99EXPORT_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 */
113int 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}
143EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
144
145static 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;
176out:
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
188static struct acpi_device *
189usb_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
221static struct acpi_device *
222usb_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
245static struct acpi_device *
246usb_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
273static 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
311static bool usb_acpi_bus_match(struct device *dev)
312{
313	return is_usb_device(dev) || is_usb_port(dev);
314}
315
316static 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
322int usb_acpi_register(void)
323{
324	return register_acpi_bus_type(&usb_acpi_bus);
325}
326
327void usb_acpi_unregister(void)
328{
329	unregister_acpi_bus_type(&usb_acpi_bus);
330}