usb-acpi.c

  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
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 */
158static int usb_acpi_add_usb4_devlink(struct usb_device *udev)
159{
160	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	if (!hub)
169		return 0;
170	port_dev = hub->ports[udev->portnum - 1];
171
172	struct fwnode_handle *nhi_fwnode __free(fwnode_handle) =
173		fwnode_find_reference(dev_fwnode(&port_dev->dev), "usb4-host-interface", 0);
174
175	if (IS_ERR(nhi_fwnode) || !nhi_fwnode->dev)
176		return 0;
177
178	link = device_link_add(&port_dev->child->dev, nhi_fwnode->dev,
179			       DL_FLAG_STATELESS |
180			       DL_FLAG_RPM_ACTIVE |
181			       DL_FLAG_PM_RUNTIME);
182	if (!link) {
183		dev_err(&port_dev->dev, "Failed to created device link from %s to %s\n",
184			dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));
185		return -EINVAL;
186	}
187
188	dev_dbg(&port_dev->dev, "Created device link from %s to %s\n",
189		dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));
190
191	udev->usb4_link = link;
192
193	return 0;
194}
195
196/*
197 * Private to usb-acpi, all the core needs to know is that
198 * port_dev->location is non-zero when it has been set by the firmware.
199 */
200#define USB_ACPI_LOCATION_VALID (1 << 31)
201
202static void
203usb_acpi_get_connect_type(struct usb_port *port_dev, acpi_handle *handle)
204{
205	enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
206	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
207	union acpi_object *upc = NULL;
208	struct acpi_pld_info *pld = NULL;
209	acpi_status status;
210
211	/*
212	 * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
213	 * is user visible and _UPC indicates whether it is connectable. If
214	 * the port was visible and connectable, it could be freely connected
215	 * and disconnected with USB devices. If no visible and connectable,
216	 * a usb device is directly hard-wired to the port. If no visible and
217	 * no connectable, the port would be not used.
218	 */
219
220	if (acpi_get_physical_device_location(handle, &pld) && pld)
221		port_dev->location = USB_ACPI_LOCATION_VALID |
222			pld->group_token << 8 | pld->group_position;
223
224	status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
225	if (ACPI_FAILURE(status))
226		goto out;
227
228	upc = buffer.pointer;
229	if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
230		goto out;
231
232	/* UPC states port is connectable */
233	if (upc->package.elements[0].integer.value)
234		if (!pld)
235			; /* keep connect_type as unknown */
236		else if (pld->user_visible)
237			connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
238		else
239			connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
240	else
241		connect_type = USB_PORT_NOT_USED;
242out:
243	port_dev->connect_type = connect_type;
244	kfree(upc);
245	ACPI_FREE(pld);
246}
247
248static struct acpi_device *
249usb_acpi_get_companion_for_port(struct usb_port *port_dev)
250{
251	struct usb_device *udev;
252	struct acpi_device *adev;
253	acpi_handle *parent_handle;
254	int port1;
255
256	/* Get the struct usb_device point of port's hub */
257	udev = to_usb_device(port_dev->dev.parent->parent);
258
259	/*
260	 * The root hub ports' parent is the root hub. The non-root-hub
261	 * ports' parent is the parent hub port which the hub is
262	 * connected to.
263	 */
264	if (!udev->parent) {
265		adev = ACPI_COMPANION(&udev->dev);
266		port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
267						     port_dev->portnum);
268	} else {
269		parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
270							     udev->portnum);
271		if (!parent_handle)
272			return NULL;
273
274		adev = acpi_fetch_acpi_dev(parent_handle);
275		port1 = port_dev->portnum;
276	}
277
278	return acpi_find_child_by_adr(adev, port1);
279}
280
281static struct acpi_device *
282usb_acpi_find_companion_for_port(struct usb_port *port_dev)
283{
284	struct acpi_device *adev;
285
286	adev = usb_acpi_get_companion_for_port(port_dev);
287	if (!adev)
288		return NULL;
289
290	usb_acpi_get_connect_type(port_dev, adev->handle);
291
292	return adev;
293}
294
295static struct acpi_device *
296usb_acpi_find_companion_for_device(struct usb_device *udev)
297{
298	struct acpi_device *adev;
299	struct usb_port *port_dev;
300	struct usb_hub *hub;
301
302	if (!udev->parent) {
303		/*
304		 * root hub is only child (_ADR=0) under its parent, the HC.
305		 * sysdev pointer is the HC as seen from firmware.
306		 */
307		adev = ACPI_COMPANION(udev->bus->sysdev);
308		return acpi_find_child_device(adev, 0, false);
309	}
310
311	hub = usb_hub_to_struct_hub(udev->parent);
312	if (!hub)
313		return NULL;
314
315
316	/* Tunneled USB3 devices depend on USB4 Host Interface, set device link to it */
317	if (udev->speed >= USB_SPEED_SUPER &&
318	    udev->tunnel_mode != USB_LINK_NATIVE)
319		usb_acpi_add_usb4_devlink(udev);
320
321	/*
322	 * This is an embedded USB device connected to a port and such
323	 * devices share port's ACPI companion.
324	 */
325	port_dev = hub->ports[udev->portnum - 1];
326	return usb_acpi_get_companion_for_port(port_dev);
327}
328
329static struct acpi_device *usb_acpi_find_companion(struct device *dev)
330{
331	/*
332	 * The USB hierarchy like following:
333	 *
334	 * Device (EHC1)
335	 *	Device (HUBN)
336	 *		Device (PR01)
337	 *			Device (PR11)
338	 *			Device (PR12)
339	 *				Device (FN12)
340	 *				Device (FN13)
341	 *			Device (PR13)
342	 *			...
343	 * where HUBN is root hub, and PRNN are USB ports and devices
344	 * connected to them, and FNNN are individualk functions for
345	 * connected composite USB devices. PRNN and FNNN may contain
346	 * _CRS and other methods describing sideband resources for
347	 * the connected device.
348	 *
349	 * On the kernel side both root hub and embedded USB devices are
350	 * represented as instances of usb_device structure, and ports
351	 * are represented as usb_port structures, so the whole process
352	 * is split into 2 parts: finding companions for devices and
353	 * finding companions for ports.
354	 *
355	 * Note that we do not handle individual functions of composite
356	 * devices yet, for that we would need to assign companions to
357	 * devices corresponding to USB interfaces.
358	 */
359	if (is_usb_device(dev))
360		return usb_acpi_find_companion_for_device(to_usb_device(dev));
361	else if (is_usb_port(dev))
362		return usb_acpi_find_companion_for_port(to_usb_port(dev));
363
364	return NULL;
365}
366
367static bool usb_acpi_bus_match(struct device *dev)
368{
369	return is_usb_device(dev) || is_usb_port(dev);
370}
371
372static struct acpi_bus_type usb_acpi_bus = {
373	.name = "USB",
374	.match = usb_acpi_bus_match,
375	.find_companion = usb_acpi_find_companion,
376};
377
378int usb_acpi_register(void)
379{
380	return register_acpi_bus_type(&usb_acpi_bus);
381}
382
383void usb_acpi_unregister(void)
384{
385	unregister_acpi_bus_type(&usb_acpi_bus);
386}