summaryrefslogtreecommitdiffstats
path: root/drivers/usb/otg/otg.c
blob: 88d62b16f63273a712c42302337050f7c04ffded (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
227
228
229
230
231
232
233
234
235
236
/*
 * otg.c -- USB OTG utility code
 *
 * Copyright (C) 2004 Texas Instruments
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/slab.h>

#include <linux/usb/otg.h>

static LIST_HEAD(phy_list);
static DEFINE_SPINLOCK(phy_lock);

static struct usb_phy *__usb_find_phy(struct list_head *list,
	enum usb_phy_type type)
{
	struct usb_phy  *phy = NULL;

	list_for_each_entry(phy, list, head) {
		if (phy->type != type)
			continue;

		return phy;
	}

	return ERR_PTR(-ENODEV);
}

static void devm_usb_phy_release(struct device *dev, void *res)
{
	struct usb_phy *phy = *(struct usb_phy **)res;

	usb_put_phy(phy);
}

static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
{
	return res == match_data;
}

/**
 * devm_usb_get_phy - find the USB PHY
 * @dev - device that requests this phy
 * @type - the type of the phy the controller requires
 *
 * Gets the phy using usb_get_phy(), and associates a device with it using
 * devres. On driver detach, release function is invoked on the devres data,
 * then, devres data is freed.
 *
 * For use by USB host and peripheral drivers.
 */
struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type)
{
	struct usb_phy **ptr, *phy;

	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return NULL;

	phy = usb_get_phy(type);
	if (!IS_ERR(phy)) {
		*ptr = phy;
		devres_add(dev, ptr);
	} else
		devres_free(ptr);

	return phy;
}
EXPORT_SYMBOL(devm_usb_get_phy);

/**
 * usb_get_phy - find the USB PHY
 * @type - the type of the phy the controller requires
 *
 * Returns the phy driver, after getting a refcount to it; or
 * -ENODEV if there is no such phy.  The caller is responsible for
 * calling usb_put_phy() to release that count.
 *
 * For use by USB host and peripheral drivers.
 */
struct usb_phy *usb_get_phy(enum usb_phy_type type)
{
	struct usb_phy	*phy = NULL;
	unsigned long	flags;

	spin_lock_irqsave(&phy_lock, flags);

	phy = __usb_find_phy(&phy_list, type);
	if (IS_ERR(phy)) {
		pr_err("unable to find transceiver of type %s\n",
			usb_phy_type_string(type));
		return phy;
	}

	get_device(phy->dev);

	spin_unlock_irqrestore(&phy_lock, flags);

	return phy;
}
EXPORT_SYMBOL(usb_get_phy);

/**
 * devm_usb_put_phy - release the USB PHY
 * @dev - device that wants to release this phy
 * @phy - the phy returned by devm_usb_get_phy()
 *
 * destroys the devres associated with this phy and invokes usb_put_phy
 * to release the phy.
 *
 * For use by USB host and peripheral drivers.
 */
void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
{
	int r;

	r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
}
EXPORT_SYMBOL(devm_usb_put_phy);

/**
 * usb_put_phy - release the USB PHY
 * @x: the phy returned by usb_get_phy()
 *
 * Releases a refcount the caller received from usb_get_phy().
 *
 * For use by USB host and peripheral drivers.
 */
void usb_put_phy(struct usb_phy *x)
{
	if (x)
		put_device(x->dev);
}
EXPORT_SYMBOL(usb_put_phy);

/**
 * usb_add_phy - declare the USB PHY
 * @x: the USB phy to be used; or NULL
 * @type - the type of this PHY
 *
 * This call is exclusively for use by phy drivers, which
 * coordinate the activities of drivers for host and peripheral
 * controllers, and in some cases for VBUS current regulation.
 */
int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
{
	int		ret = 0;
	unsigned long	flags;
	struct usb_phy	*phy;

	if (x && x->type != USB_PHY_TYPE_UNDEFINED) {
		dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
		return -EINVAL;
	}

	spin_lock_irqsave(&phy_lock, flags);

	list_for_each_entry(phy, &phy_list, head) {
		if (phy->type == type) {
			ret = -EBUSY;
			dev_err(x->dev, "transceiver type %s already exists\n",
						usb_phy_type_string(type));
			goto out;
		}
	}

	x->type = type;
	list_add_tail(&x->head, &phy_list);

out:
	spin_unlock_irqrestore(&phy_lock, flags);
	return ret;
}
EXPORT_SYMBOL(usb_add_phy);

/**
 * usb_remove_phy - remove the OTG PHY
 * @x: the USB OTG PHY to be removed;
 *
 * This reverts the effects of usb_add_phy
 */
void usb_remove_phy(struct usb_phy *x)
{
	unsigned long	flags;

	spin_lock_irqsave(&phy_lock, flags);
	if (x)
		list_del(&x->head);
	spin_unlock_irqrestore(&phy_lock, flags);
}
EXPORT_SYMBOL(usb_remove_phy);

const char *otg_state_string(enum usb_otg_state state)
{
	switch (state) {
	case OTG_STATE_A_IDLE:
		return "a_idle";
	case OTG_STATE_A_WAIT_VRISE:
		return "a_wait_vrise";
	case OTG_STATE_A_WAIT_BCON:
		return "a_wait_bcon";
	case OTG_STATE_A_HOST:
		return "a_host";
	case OTG_STATE_A_SUSPEND:
		return "a_suspend";
	case OTG_STATE_A_PERIPHERAL:
		return "a_peripheral";
	case OTG_STATE_A_WAIT_VFALL:
		return "a_wait_vfall";
	case OTG_STATE_A_VBUS_ERR:
		return "a_vbus_err";
	case OTG_STATE_B_IDLE:
		return "b_idle";
	case OTG_STATE_B_SRP_INIT:
		return "b_srp_init";
	case OTG_STATE_B_PERIPHERAL:
		return "b_peripheral";
	case OTG_STATE_B_WAIT_ACON:
		return "b_wait_acon";
	case OTG_STATE_B_HOST:
		return "b_host";
	default:
		return "UNDEFINED";
	}
}
EXPORT_SYMBOL(otg_state_string);