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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2017 Ian Lepore <ian@freebsd.org>
*
* Development sponsored by Microsemi, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* Helper code to recover a hung i2c bus by bit-banging a recovery sequence.
*/
#ifndef _IICBUS_IIC_RECOVER_BUS_H_
#define _IICBUS_IIC_RECOVER_BUS_H_
struct iicrb_pin_access {
void *ctx;
int (*getsda)(void *ctx);
void (*setsda)(void *ctx, int value);
int (*getscl)(void *ctx);
void (*setscl)(void *ctx, int value);
};
/*
* Drive the bus-recovery logic by manipulating the line states using the
* caller-provided functions. This does not block or sleep or acquire any locks
* (unless the provided pin access functions do so). It uses DELAY() to pace
* bits on the bus.
*
* Returns 0 if the bus is functioning properly or IIC_EBUSERR if the recovery
* attempt failed and some slave device is still driving the bus.
*/
int iic_recover_bus(struct iicrb_pin_access *pins);
#endif
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