blob: 0a43a7db750f6dc445ea4fedc771722dd07a02e3 (
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
|
/*
* 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/device.h>
#include <linux/usb/otg.h>
static struct otg_transceiver *xceiv;
/**
* otg_get_transceiver - find the (single) OTG transceiver
*
* Returns the transceiver driver, after getting a refcount to it; or
* null if there is no such transceiver. The caller is responsible for
* calling otg_put_transceiver() to release that count.
*
* For use by USB host and peripheral drivers.
*/
struct otg_transceiver *otg_get_transceiver(void)
{
if (xceiv)
get_device(xceiv->dev);
return xceiv;
}
EXPORT_SYMBOL(otg_get_transceiver);
/**
* otg_put_transceiver - release the (single) OTG transceiver
* @x: the transceiver returned by otg_get_transceiver()
*
* Releases a refcount the caller received from otg_get_transceiver().
*
* For use by USB host and peripheral drivers.
*/
void otg_put_transceiver(struct otg_transceiver *x)
{
if (x)
put_device(x->dev);
}
EXPORT_SYMBOL(otg_put_transceiver);
/**
* otg_set_transceiver - declare the (single) OTG transceiver
* @x: the USB OTG transceiver to be used; or NULL
*
* This call is exclusively for use by transceiver drivers, which
* coordinate the activities of drivers for host and peripheral
* controllers, and in some cases for VBUS current regulation.
*/
int otg_set_transceiver(struct otg_transceiver *x)
{
if (xceiv && x)
return -EBUSY;
xceiv = x;
return 0;
}
EXPORT_SYMBOL(otg_set_transceiver);
|
