mirror of https://github.com/ArduPilot/ardupilot
155 lines
5.1 KiB
C
155 lines
5.1 KiB
C
/*
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LUFA Library
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Copyright (C) Dean Camera, 2010.
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dean [at] fourwalledcubicle [dot] com
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www.fourwalledcubicle.com
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*/
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/*
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Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com)
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Permission to use, copy, modify, distribute, and sell this
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software and its documentation for any purpose is hereby granted
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without fee, provided that the above copyright notice appear in
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all copies and that both that the copyright notice and this
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permission notice and warranty disclaimer appear in supporting
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documentation, and that the name of the author not be used in
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advertising or publicity pertaining to distribution of the
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software without specific, written prior permission.
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The author disclaim all warranties with regard to this
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software, including all implied warranties of merchantability
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and fitness. In no event shall the author be liable for any
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special, indirect or consequential damages or any damages
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whatsoever resulting from loss of use, data or profits, whether
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in an action of contract, negligence or other tortious action,
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arising out of or in connection with the use or performance of
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this software.
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*/
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/** \file
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* \brief TWI peripheral driver for the U7, U6 and U4 USB AVRs.
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*
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* Master mode TWI driver for the AT90USB1287, AT90USB1286, AT90USB647, AT90USB646, ATMEGA16U4 and ATMEGA32U4 AVRs.
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*
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* \note This file should not be included directly. It is automatically included as needed by the TWI driver
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* dispatch header located in LUFA/Drivers/Peripheral/TWI.h.
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*/
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/** \ingroup Group_TWI
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* @defgroup Group_TWI_AVRU4U6U7 Series U4, U6 and U7 Model TWI Driver
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*
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* Master mode TWI driver for the AT90USB1287, AT90USB1286, AT90USB647, AT90USB646, ATMEGA16U4 and ATMEGA32U4 AVRs.
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*
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* \note This file should not be included directly. It is automatically included as needed by the TWI driver
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* dispatch header located in LUFA/Drivers/Peripheral/TWI.h.
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*
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* @{
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*/
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#ifndef __TWI_AVRU4U6U7_H__
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#define __TWI_AVRU4U6U7_H__
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/* Includes: */
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#include "../../../Common/Common.h"
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#include <avr/io.h>
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#include <stdbool.h>
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#include <util/twi.h>
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#include <util/delay.h>
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/* Enable C linkage for C++ Compilers: */
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#if defined(__cplusplus)
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extern "C" {
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#endif
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/* Preprocessor Checks: */
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#if !defined(__INCLUDE_FROM_TWI_H)
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#error Do not include this file directly. Include LUFA/Drivers/Peripheral/TWI.h instead.
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#endif
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/* Public Interface - May be used in end-application: */
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/* Inline Functions: */
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/** Initialises the TWI hardware into master mode, ready for data transmission and reception. This must be
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* before any other TWI operations.
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*/
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static inline void TWI_Init(void) ATTR_ALWAYS_INLINE;
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static inline void TWI_Init(void)
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{
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TWCR |= (1 << TWEN);
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}
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/** Turns off the TWI driver hardware. If this is called, any further TWI operations will require a call to
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* \ref TWI_Init() before the TWI can be used again.
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*/
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static inline void TWI_ShutDown(void) ATTR_ALWAYS_INLINE;
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static inline void TWI_ShutDown(void)
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{
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TWCR &= ~(1 << TWEN);
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}
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/** Sends a TWI STOP onto the TWI bus, terminating communication with the currently addressed device. */
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static inline void TWI_StopTransmission(void) ATTR_ALWAYS_INLINE;
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static inline void TWI_StopTransmission(void)
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{
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TWCR = ((1 << TWINT) | (1 << TWSTO) | (1 << TWEN));
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}
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/** Sends a byte to the currently addressed device on the TWI bus.
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*
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* \param[in] Byte Byte to send to the currently addressed device
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*
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* \return Boolean true if the recipient ACKed the byte, false otherwise
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*/
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static inline bool TWI_SendByte(const uint8_t Byte)
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{
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TWDR = Byte;
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TWCR = ((1 << TWINT) | (1 << TWEN));
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while (!(TWCR & (1 << TWINT)));
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return ((TWSR & TW_STATUS_MASK) == TW_MT_DATA_ACK);
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}
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/** Receives a byte from the currently addressed device on the TWI bus.
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*
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* \param[in] Byte Location where the read byte is to be stored
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* \param[in] LastByte Indicates if the byte should be ACKed if false, NAKed if true
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*
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* \return Boolean true if the byte reception successfully completed, false otherwise
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*/
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static inline bool TWI_ReceiveByte(uint8_t* const Byte,
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const bool LastByte)
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{
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uint8_t TWCRMask = ((1 << TWINT) | (1 << TWEN));
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if (!(LastByte))
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TWCRMask |= (1 << TWEA);
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TWCR = TWCRMask;
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while (!(TWCR & (1 << TWINT)));
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*Byte = TWDR;
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return ((TWSR & TW_STATUS_MASK) == TW_MR_DATA_ACK);
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}
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/* Function Prototypes: */
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/** Begins a master mode TWI bus communication with the given slave device address.
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*
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* \param[in] SlaveAddress Address of the slave TWI device to communicate with
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* \param[in] TimeoutMS Timeout period within which the slave must respond, in milliseconds
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*
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* \return Boolean true if the device is ready for data, false otherwise
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*/
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bool TWI_StartTransmission(const uint8_t SlaveAddress,
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const uint8_t TimeoutMS);
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/* Disable C linkage for C++ Compilers: */
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#if defined(__cplusplus)
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}
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#endif
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#endif
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/** @} */
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