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  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/**
 41 * usb_acpi_set_power_state - control usb port's power via acpi power
 42 * resource
 43 * @hdev: USB device belonging to the usb hub
 44 * @index: port index based zero
 45 * @enable: power state expected to be set
 46 *
 47 * Notice to use usb_acpi_power_manageable() to check whether the usb port
 48 * has acpi power resource before invoking this function.
 49 *
 50 * Returns 0 on success, else negative errno.
 51 */
 52int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
 53{
 54	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
 55	struct usb_port *port_dev;
 56	acpi_handle port_handle;
 57	unsigned char state;
 58	int port1 = index + 1;
 59	int error = -EINVAL;
 60
 61	if (!hub)
 62		return -ENODEV;
 63	port_dev = hub->ports[port1 - 1];
 64
 65	port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
 66	if (!port_handle)
 67		return error;
 68
 69	if (enable)
 70		state = ACPI_STATE_D0;
 71	else
 72		state = ACPI_STATE_D3_COLD;
 73
 74	error = acpi_bus_set_power(port_handle, state);
 75	if (!error)
 76		dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
 77	else
 78		dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
 79
 80	return error;
 81}
 82EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
 83
 84static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
 85		struct acpi_pld_info *pld)
 86{
 87	enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
 88	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 89	union acpi_object *upc = NULL;
 90	acpi_status status;
 91
 92	/*
 93	 * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
 94	 * is user visible and _UPC indicates whether it is connectable. If
 95	 * the port was visible and connectable, it could be freely connected
 96	 * and disconnected with USB devices. If no visible and connectable,
 97	 * a usb device is directly hard-wired to the port. If no visible and
 98	 * no connectable, the port would be not used.
 99	 */
100	status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
101	if (ACPI_FAILURE(status))
102		goto out;
103
104	upc = buffer.pointer;
105	if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
106		goto out;
107
108	if (upc->package.elements[0].integer.value)
109		if (pld->user_visible)
110			connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
111		else
112			connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
113	else if (!pld->user_visible)
114		connect_type = USB_PORT_NOT_USED;
115out:
116	kfree(upc);
117	return connect_type;
118}
119
120
121/*
122 * Private to usb-acpi, all the core needs to know is that
123 * port_dev->location is non-zero when it has been set by the firmware.
124 */
125#define USB_ACPI_LOCATION_VALID (1 << 31)
126
127static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
128					      int raw)
129{
130	struct acpi_device *adev;
131
132	if (!parent)
133		return NULL;
134
135	list_for_each_entry(adev, &parent->children, node) {
136		if (acpi_device_adr(adev) == raw)
137			return adev;
138	}
139
140	return acpi_find_child_device(parent, raw, false);
141}
142
143static struct acpi_device *
144usb_acpi_get_companion_for_port(struct usb_port *port_dev)
145{
146	struct usb_device *udev;
147	struct acpi_device *adev;
148	acpi_handle *parent_handle;
149	int port1;
150
151	/* Get the struct usb_device point of port's hub */
152	udev = to_usb_device(port_dev->dev.parent->parent);
153
154	/*
155	 * The root hub ports' parent is the root hub. The non-root-hub
156	 * ports' parent is the parent hub port which the hub is
157	 * connected to.
158	 */
159	if (!udev->parent) {
160		adev = ACPI_COMPANION(&udev->dev);
161		port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
162						     port_dev->portnum);
163	} else {
164		parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
165							     udev->portnum);
166		if (!parent_handle)
167			return NULL;
168
169		acpi_bus_get_device(parent_handle, &adev);
170		port1 = port_dev->portnum;
171	}
172
173	return usb_acpi_find_port(adev, port1);
174}
175
176static struct acpi_device *
177usb_acpi_find_companion_for_port(struct usb_port *port_dev)
178{
179	struct acpi_device *adev;
180	struct acpi_pld_info *pld;
181	acpi_handle *handle;
182	acpi_status status;
183
184	adev = usb_acpi_get_companion_for_port(port_dev);
185	if (!adev)
186		return NULL;
187
188	handle = adev->handle;
189	status = acpi_get_physical_device_location(handle, &pld);
190	if (ACPI_SUCCESS(status) && pld) {
191		port_dev->location = USB_ACPI_LOCATION_VALID
192			| pld->group_token << 8 | pld->group_position;
193		port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
194		ACPI_FREE(pld);
195	}
196
197	return adev;
198}
199
200static struct acpi_device *
201usb_acpi_find_companion_for_device(struct usb_device *udev)
202{
203	struct acpi_device *adev;
204	struct usb_port *port_dev;
205	struct usb_hub *hub;
206
207	if (!udev->parent) {
208		/* root hub is only child (_ADR=0) under its parent, the HC */
209		adev = ACPI_COMPANION(udev->dev.parent);
210		return acpi_find_child_device(adev, 0, false);
211	}
212
213	hub = usb_hub_to_struct_hub(udev->parent);
214	if (!hub)
215		return NULL;
216
217	/*
218	 * This is an embedded USB device connected to a port and such
219	 * devices share port's ACPI companion.
220	 */
221	port_dev = hub->ports[udev->portnum - 1];
222	return usb_acpi_get_companion_for_port(port_dev);
223}
224
225static struct acpi_device *usb_acpi_find_companion(struct device *dev)
226{
227	/*
228	 * The USB hierarchy like following:
229	 *
230	 * Device (EHC1)
231	 *	Device (HUBN)
232	 *		Device (PR01)
233	 *			Device (PR11)
234	 *			Device (PR12)
235	 *				Device (FN12)
236	 *				Device (FN13)
237	 *			Device (PR13)
238	 *			...
239	 * where HUBN is root hub, and PRNN are USB ports and devices
240	 * connected to them, and FNNN are individualk functions for
241	 * connected composite USB devices. PRNN and FNNN may contain
242	 * _CRS and other methods describing sideband resources for
243	 * the connected device.
244	 *
245	 * On the kernel side both root hub and embedded USB devices are
246	 * represented as instances of usb_device structure, and ports
247	 * are represented as usb_port structures, so the whole process
248	 * is split into 2 parts: finding companions for devices and
249	 * finding companions for ports.
250	 *
251	 * Note that we do not handle individual functions of composite
252	 * devices yet, for that we would need to assign companions to
253	 * devices corresponding to USB interfaces.
254	 */
255	if (is_usb_device(dev))
256		return usb_acpi_find_companion_for_device(to_usb_device(dev));
257	else if (is_usb_port(dev))
258		return usb_acpi_find_companion_for_port(to_usb_port(dev));
259
260	return NULL;
261}
262
263static bool usb_acpi_bus_match(struct device *dev)
264{
265	return is_usb_device(dev) || is_usb_port(dev);
266}
267
268static struct acpi_bus_type usb_acpi_bus = {
269	.name = "USB",
270	.match = usb_acpi_bus_match,
271	.find_companion = usb_acpi_find_companion,
272};
273
274int usb_acpi_register(void)
275{
276	return register_acpi_bus_type(&usb_acpi_bus);
277}
278
279void usb_acpi_unregister(void)
280{
281	unregister_acpi_bus_type(&usb_acpi_bus);
282}