/* * 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);