M7350/kernel/drivers/usb/otg/otg.c

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2024-09-09 08:52:07 +00:00
/*
* 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/device.h>
#include <linux/usb/otg.h>
static struct usb_phy *phy;
/**
* usb_get_transceiver - find the (single) USB 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 usb_put_transceiver() to release that count.
*
* For use by USB host and peripheral drivers.
*/
struct usb_phy *usb_get_transceiver(void)
{
if (phy)
get_device(phy->dev);
return phy;
}
EXPORT_SYMBOL(usb_get_transceiver);
/**
* usb_put_transceiver - release the (single) USB transceiver
* @x: the transceiver returned by usb_get_transceiver()
*
* Releases a refcount the caller received from usb_get_transceiver().
*
* For use by USB host and peripheral drivers.
*/
void usb_put_transceiver(struct usb_phy *x)
{
if (x)
put_device(x->dev);
}
EXPORT_SYMBOL(usb_put_transceiver);
/**
* usb_set_transceiver - declare the (single) USB transceiver
* @x: the USB 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 usb_set_transceiver(struct usb_phy *x)
{
if (phy && x)
return -EBUSY;
phy = x;
return 0;
}
EXPORT_SYMBOL(usb_set_transceiver);
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);
int otg_send_event(enum usb_otg_event event)
{
struct usb_phy *phy = usb_get_transceiver();
int ret = -ENOTSUPP;
if (phy && phy->otg && phy->otg->send_event)
ret = phy->otg->send_event(phy->otg, event);
if (phy)
usb_put_transceiver(phy);
return ret;
}
EXPORT_SYMBOL(otg_send_event);