summaryrefslogtreecommitdiffstats
path: root/drivers/usb/core/usb-acpi.c
blob: 0ef7d42d8abe85e77f7fdac7778b7e1220e41c49 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
/*
 * USB-ACPI glue code
 *
 * Copyright 2012 Red Hat <mjg@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation, version 2.
 *
 */
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/pci.h>
#include <acpi/acpi_bus.h>

#include "usb.h"

/**
 * usb_acpi_power_manageable - check whether usb port has
 * acpi power resource.
 * @hdev: USB device belonging to the usb hub
 * @index: port index based zero
 *
 * Return true if the port has acpi power resource and false if no.
 */
bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
{
	acpi_handle port_handle;
	int port1 = index + 1;

	port_handle = usb_get_hub_port_acpi_handle(hdev,
		port1);
	if (port_handle)
		return acpi_bus_power_manageable(port_handle);
	else
		return false;
}
EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);

/**
 * usb_acpi_set_power_state - control usb port's power via acpi power
 * resource
 * @hdev: USB device belonging to the usb hub
 * @index: port index based zero
 * @enable: power state expected to be set
 *
 * Notice to use usb_acpi_power_manageable() to check whether the usb port
 * has acpi power resource before invoking this function.
 *
 * Returns 0 on success, else negative errno.
 */
int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
{
	acpi_handle port_handle;
	unsigned char state;
	int port1 = index + 1;
	int error = -EINVAL;

	port_handle = (acpi_handle)usb_get_hub_port_acpi_handle(hdev,
		port1);
	if (!port_handle)
		return error;

	if (enable)
		state = ACPI_STATE_D0;
	else
		state = ACPI_STATE_D3_COLD;

	error = acpi_bus_set_power(port_handle, state);
	if (!error)
		dev_dbg(&hdev->dev, "The power of hub port %d was set to %d\n",
			port1, enable);
	else
		dev_dbg(&hdev->dev, "The power of hub port failed to be set\n");

	return error;
}
EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);

static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
	acpi_handle handle, int port1)
{
	acpi_status status;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *upc;
	struct acpi_pld pld;
	int ret = 0;

	/*
	 * Accoding to ACPI Spec 9.13. PLD indicates whether usb port is
	 * user visible and _UPC indicates whether it is connectable. If
	 * the port was visible and connectable, it could be freely connected
	 * and disconnected with USB devices. If no visible and connectable,
	 * a usb device is directly hard-wired to the port. If no visible and
	 * no connectable, the port would be not used.
	 */
	status = acpi_get_physical_device_location(handle, &pld);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
	upc = buffer.pointer;
	if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
		|| upc->package.count != 4) {
		ret = -EINVAL;
		goto out;
	}

	if (upc->package.elements[0].integer.value)
		if (pld.user_visible)
			usb_set_hub_port_connect_type(hdev, port1,
				USB_PORT_CONNECT_TYPE_HOT_PLUG);
		else
			usb_set_hub_port_connect_type(hdev, port1,
				USB_PORT_CONNECT_TYPE_HARD_WIRED);
	else if (!pld.user_visible)
		usb_set_hub_port_connect_type(hdev, port1, USB_PORT_NOT_USED);

out:
	kfree(upc);
	return ret;
}

static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
{
	struct usb_device *udev;
	acpi_handle *parent_handle;
	int port_num;

	/*
	 * In the ACPI DSDT table, only usb root hub and usb ports are
	 * acpi device nodes. The hierarchy like following.
	 * Device (EHC1)
	 *	Device (HUBN)
	 *		Device (PR01)
	 *			Device (PR11)
	 *			Device (PR12)
	 *			Device (PR13)
	 *			...
	 * So all binding process is divided into two parts. binding
	 * root hub and usb ports.
	 */
	if (is_usb_device(dev)) {
		udev = to_usb_device(dev);
		if (udev->parent) {
			enum usb_port_connect_type type;

			/*
			 * According usb port's connect type to set usb device's
			 * removability.
			 */
			type = usb_get_hub_port_connect_type(udev->parent,
				udev->portnum);
			switch (type) {
			case USB_PORT_CONNECT_TYPE_HOT_PLUG:
				udev->removable = USB_DEVICE_REMOVABLE;
				break;
			case USB_PORT_CONNECT_TYPE_HARD_WIRED:
				udev->removable = USB_DEVICE_FIXED;
				break;
			default:
				udev->removable = USB_DEVICE_REMOVABLE_UNKNOWN;
				break;
			}

			return -ENODEV;
		}

		/* root hub's parent is the usb hcd. */
		parent_handle = DEVICE_ACPI_HANDLE(dev->parent);
		*handle = acpi_get_child(parent_handle, udev->portnum);
		if (!*handle)
			return -ENODEV;
		return 0;
	} else if (is_usb_port(dev)) {
		sscanf(dev_name(dev), "port%d", &port_num);
		/* Get the struct usb_device point of port's hub */
		udev = to_usb_device(dev->parent->parent);

		/*
		 * The root hub ports' parent is the root hub. The non-root-hub
		 * ports' parent is the parent hub port which the hub is
		 * connected to.
		 */
		if (!udev->parent) {
			*handle = acpi_get_child(DEVICE_ACPI_HANDLE(&udev->dev),
				port_num);
			if (!*handle)
				return -ENODEV;
		} else {
			parent_handle =
				usb_get_hub_port_acpi_handle(udev->parent,
				udev->portnum);
			if (!parent_handle)
				return -ENODEV;

			*handle = acpi_get_child(parent_handle,	port_num);
			if (!*handle)
				return -ENODEV;
		}
		usb_acpi_check_port_connect_type(udev, *handle, port_num);
	} else
		return -ENODEV;

	return 0;
}

static struct acpi_bus_type usb_acpi_bus = {
	.bus = &usb_bus_type,
	.find_bridge = usb_acpi_find_device,
	.find_device = usb_acpi_find_device,
};

int usb_acpi_register(void)
{
	return register_acpi_bus_type(&usb_acpi_bus);
}

void usb_acpi_unregister(void)
{
	unregister_acpi_bus_type(&usb_acpi_bus);
}