blob: e2fda26b7b84a46425e5e2ff3a456f5bab921ed0 [file] [log] [blame]
/* Copyright 2012 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* 1-wire interface for Chrome EC */
/*
* Note that 1-wire communication is VERY latency-sensitive. If these
* functions are run at low priority, communication may be garbled. However,
* these functions are also slow enough (~1ms per call) that it's really not
* desirable to put them at high priority. So make sure you check the
* confirmation code from the slave for any communication, and retry a few
* times in case of failure.
*/
#ifndef __CROS_EC_ONEWIRE_H
#define __CROS_EC_ONEWIRE_H
#include "common.h"
/**
* Reset the 1-wire bus.
*
* @return EC_SUCCESS, or non-zero if presence detect fails.
*/
int onewire_reset(void);
/**
* Read a byte from the 1-wire bus.
*
* @return The byte value read.
*/
int onewire_read(void);
/**
* Write a byte to the 1-wire bus.
*
* @param data Byte to write
*/
void onewire_write(int data);
#endif /* __CROS_EC_ONEWIRE_H */