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 *
193usb_acpi_get_companion_for_port(struct usb_port *port_dev)
194{
195	struct usb_device *udev;
196	struct acpi_device *adev;
197	acpi_handle *parent_handle;
198	int port1;
199
200	/* Get the struct usb_device point of port's hub */
201	udev = to_usb_device(port_dev->dev.parent->parent);
202
203	/*
204	 * The root hub ports' parent is the root hub. The non-root-hub
205	 * ports' parent is the parent hub port which the hub is
206	 * connected to.
207	 */
208	if (!udev->parent) {
209		adev = ACPI_COMPANION(&udev->dev);
210		port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
211						     port_dev->portnum);
212	} else {
213		parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
214							     udev->portnum);
215		if (!parent_handle)
216			return NULL;
217
218		adev = acpi_fetch_acpi_dev(parent_handle);
219		port1 = port_dev->portnum;
220	}
221
222	return acpi_find_child_by_adr(adev, port1);
223}
224
225static struct acpi_device *
226usb_acpi_find_companion_for_port(struct usb_port *port_dev)
227{
228	struct acpi_device *adev;
229	struct acpi_pld_info *pld;
230	acpi_handle *handle;
231	acpi_status status;
232
233	adev = usb_acpi_get_companion_for_port(port_dev);
234	if (!adev)
235		return NULL;
236
237	handle = adev->handle;
238	status = acpi_get_physical_device_location(handle, &pld);
239	if (ACPI_SUCCESS(status) && pld) {
240		port_dev->location = USB_ACPI_LOCATION_VALID
241			| pld->group_token << 8 | pld->group_position;
242		port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
243		ACPI_FREE(pld);
244	}
245
246	return adev;
247}
248
249static struct acpi_device *
250usb_acpi_find_companion_for_device(struct usb_device *udev)
251{
252	struct acpi_device *adev;
253	struct usb_port *port_dev;
254	struct usb_hub *hub;
255
256	if (!udev->parent) {
257		/*
258		 * root hub is only child (_ADR=0) under its parent, the HC.
259		 * sysdev pointer is the HC as seen from firmware.
260		 */
261		adev = ACPI_COMPANION(udev->bus->sysdev);
262		return acpi_find_child_device(adev, 0, false);
263	}
264
265	hub = usb_hub_to_struct_hub(udev->parent);
266	if (!hub)
267		return NULL;
268
269	/*
270	 * This is an embedded USB device connected to a port and such
271	 * devices share port's ACPI companion.
272	 */
273	port_dev = hub->ports[udev->portnum - 1];
274	return usb_acpi_get_companion_for_port(port_dev);
275}
276
277static struct acpi_device *usb_acpi_find_companion(struct device *dev)
278{
279	/*
280	 * The USB hierarchy like following:
281	 *
282	 * Device (EHC1)
283	 *	Device (HUBN)
284	 *		Device (PR01)
285	 *			Device (PR11)
286	 *			Device (PR12)
287	 *				Device (FN12)
288	 *				Device (FN13)
289	 *			Device (PR13)
290	 *			...
291	 * where HUBN is root hub, and PRNN are USB ports and devices
292	 * connected to them, and FNNN are individualk functions for
293	 * connected composite USB devices. PRNN and FNNN may contain
294	 * _CRS and other methods describing sideband resources for
295	 * the connected device.
296	 *
297	 * On the kernel side both root hub and embedded USB devices are
298	 * represented as instances of usb_device structure, and ports
299	 * are represented as usb_port structures, so the whole process
300	 * is split into 2 parts: finding companions for devices and
301	 * finding companions for ports.
302	 *
303	 * Note that we do not handle individual functions of composite
304	 * devices yet, for that we would need to assign companions to
305	 * devices corresponding to USB interfaces.
306	 */
307	if (is_usb_device(dev))
308		return usb_acpi_find_companion_for_device(to_usb_device(dev));
309	else if (is_usb_port(dev))
310		return usb_acpi_find_companion_for_port(to_usb_port(dev));
311
312	return NULL;
313}
314
315static bool usb_acpi_bus_match(struct device *dev)
316{
317	return is_usb_device(dev) || is_usb_port(dev);
318}
319
320static struct acpi_bus_type usb_acpi_bus = {
321	.name = "USB",
322	.match = usb_acpi_bus_match,
323	.find_companion = usb_acpi_find_companion,
324};
325
326int usb_acpi_register(void)
327{
328	return register_acpi_bus_type(&usb_acpi_bus);
329}
330
331void usb_acpi_unregister(void)
332{
333	unregister_acpi_bus_type(&usb_acpi_bus);
334}