305 lines
13 KiB
C
305 lines
13 KiB
C
/*
|
|
LUFA Library
|
|
Copyright (C) Dean Camera, 2017.
|
|
|
|
dean [at] fourwalledcubicle [dot] com
|
|
www.lufa-lib.org
|
|
*/
|
|
|
|
/*
|
|
Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com)
|
|
|
|
Permission to use, copy, modify, distribute, and sell this
|
|
software and its documentation for any purpose is hereby granted
|
|
without fee, provided that the above copyright notice appear in
|
|
all copies and that both that the copyright notice and this
|
|
permission notice and warranty disclaimer appear in supporting
|
|
documentation, and that the name of the author not be used in
|
|
advertising or publicity pertaining to distribution of the
|
|
software without specific, written prior permission.
|
|
|
|
The author disclaims all warranties with regard to this
|
|
software, including all implied warranties of merchantability
|
|
and fitness. In no event shall the author be liable for any
|
|
special, indirect or consequential damages or any damages
|
|
whatsoever resulting from loss of use, data or profits, whether
|
|
in an action of contract, negligence or other tortious action,
|
|
arising out of or in connection with the use or performance of
|
|
this software.
|
|
*/
|
|
|
|
/** \file
|
|
* \brief TWI Peripheral Driver (AVR8)
|
|
*
|
|
* On-chip TWI driver for the 8-bit AVR microcontrollers.
|
|
*
|
|
* \note This file should not be included directly. It is automatically included as needed by the TWI driver
|
|
* dispatch header located in LUFA/Drivers/Peripheral/TWI.h.
|
|
*/
|
|
|
|
/** \ingroup Group_TWI
|
|
* \defgroup Group_TWI_AVR8 TWI Peripheral Driver (AVR8)
|
|
*
|
|
* \section Sec_TWI_AVR8_ModDescription Module Description
|
|
* Master mode TWI driver for the 8-bit AVR microcontrollers which contain a hardware TWI module.
|
|
*
|
|
* \note This file should not be included directly. It is automatically included as needed by the TWI driver
|
|
* dispatch header located in LUFA/Drivers/Peripheral/TWI.h.
|
|
*
|
|
* \section Sec_TWI_AVR8_ExampleUsage Example Usage
|
|
* The following snippet is an example of how this module may be used within a typical
|
|
* application.
|
|
*
|
|
* <b>Low Level API Example:</b>
|
|
* \code
|
|
* // Initialize the TWI driver before first use at 200KHz
|
|
* TWI_Init(TWI_BIT_PRESCALE_1, TWI_BITLENGTH_FROM_FREQ(1, 200000));
|
|
*
|
|
* // Start a write session to device at device address 0xA0, internal address 0xDC with a 10ms timeout
|
|
* if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_WRITE, 10) == TWI_ERROR_NoError)
|
|
* {
|
|
* TWI_SendByte(0xDC);
|
|
*
|
|
* TWI_SendByte(0x01);
|
|
* TWI_SendByte(0x02);
|
|
* TWI_SendByte(0x03);
|
|
*
|
|
* // Must stop transmission afterwards to release the bus
|
|
* TWI_StopTransmission();
|
|
* }
|
|
*
|
|
* // Start a read session to device at address 0xA0, internal address 0xDC with a 10ms timeout
|
|
* if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_WRITE, 10) == TWI_ERROR_NoError)
|
|
* {
|
|
* TWI_SendByte(0xDC);
|
|
* TWI_StopTransmission();
|
|
*
|
|
* if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_READ, 10) == TWI_ERROR_NoError)
|
|
* {
|
|
* uint8_t Byte1, Byte2, Byte3;
|
|
*
|
|
* // Read three bytes, acknowledge after the third byte is received
|
|
* TWI_ReceiveByte(&Byte1, false);
|
|
* TWI_ReceiveByte(&Byte2, false);
|
|
* TWI_ReceiveByte(&Byte3, true);
|
|
*
|
|
* // Must stop transmission afterwards to release the bus
|
|
* TWI_StopTransmission();
|
|
* }
|
|
* }
|
|
* \endcode
|
|
*
|
|
* <b>High Level API Example:</b>
|
|
* \code
|
|
* // Initialize the TWI driver before first use at 200KHz
|
|
* TWI_Init(TWI_BIT_PRESCALE_1, TWI_BITLENGTH_FROM_FREQ(1, 200000));
|
|
*
|
|
* // Start a write session to device at device address 0xA0, internal address 0xDC with a 10ms timeout
|
|
* uint8_t InternalWriteAddress = 0xDC;
|
|
* uint8_t WritePacket[3] = {0x01, 0x02, 0x03};
|
|
*
|
|
* TWI_WritePacket(0xA0, 10, &InternalWriteAddress, sizeof(InternalWriteAddress),
|
|
* &WritePacket, sizeof(WritePacket);
|
|
*
|
|
* // Start a read session to device at address 0xA0, internal address 0xDC with a 10ms timeout
|
|
* uint8_t InternalReadAddress = 0xDC;
|
|
* uint8_t ReadPacket[3];
|
|
*
|
|
* TWI_ReadPacket(0xA0, 10, &InternalReadAddress, sizeof(InternalReadAddress),
|
|
* &ReadPacket, sizeof(ReadPacket);
|
|
* \endcode
|
|
*
|
|
* @{
|
|
*/
|
|
|
|
#ifndef __TWI_AVR8_H__
|
|
#define __TWI_AVR8_H__
|
|
|
|
/* Includes: */
|
|
#include "../../../Common/Common.h"
|
|
|
|
#include <stdio.h>
|
|
#include <util/twi.h>
|
|
|
|
/* Enable C linkage for C++ Compilers: */
|
|
#if defined(__cplusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
/* Preprocessor Checks: */
|
|
#if !defined(__INCLUDE_FROM_TWI_H) && !defined(__INCLUDE_FROM_TWI_C)
|
|
#error Do not include this file directly. Include LUFA/Drivers/Peripheral/TWI.h instead.
|
|
#endif
|
|
|
|
#if !(defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
|
|
defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
|
|
defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
|
|
#error The TWI peripheral driver is not currently available for your selected microcontroller model.
|
|
#endif
|
|
|
|
/* Public Interface - May be used in end-application: */
|
|
/* Macros: */
|
|
/** TWI slave device address mask for a read session. Mask with a slave device base address to obtain
|
|
* the correct TWI bus address for the slave device when reading data from it.
|
|
*/
|
|
#define TWI_ADDRESS_READ 0x01
|
|
|
|
/** TWI slave device address mask for a write session. Mask with a slave device base address to obtain
|
|
* the correct TWI bus address for the slave device when writing data to it.
|
|
*/
|
|
#define TWI_ADDRESS_WRITE 0x00
|
|
|
|
/** Mask to retrieve the base address for a TWI device, which can then be ORed with \ref TWI_ADDRESS_READ
|
|
* or \ref TWI_ADDRESS_WRITE to obtain the device's read and write address respectively.
|
|
*/
|
|
#define TWI_DEVICE_ADDRESS_MASK 0xFE
|
|
|
|
/** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 1. */
|
|
#define TWI_BIT_PRESCALE_1 ((0 << TWPS1) | (0 << TWPS0))
|
|
|
|
/** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 4. */
|
|
#define TWI_BIT_PRESCALE_4 ((0 << TWPS1) | (1 << TWPS0))
|
|
|
|
/** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 16. */
|
|
#define TWI_BIT_PRESCALE_16 ((1 << TWPS1) | (0 << TWPS0))
|
|
|
|
/** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 64. */
|
|
#define TWI_BIT_PRESCALE_64 ((1 << TWPS1) | (1 << TWPS0))
|
|
|
|
/** Calculates the length of each bit on the TWI bus for a given target frequency. This may be used with
|
|
* the \ref TWI_Init() function to convert a bus frequency to a number of clocks for the \c BitLength
|
|
* parameter.
|
|
*
|
|
* \param[in] Prescale Prescaler set on the TWI bus.
|
|
* \param[in] Frequency Desired TWI bus frequency in Hz.
|
|
*
|
|
* \return Bit length in clocks for the given TWI bus frequency at the given prescaler value.
|
|
*/
|
|
#define TWI_BITLENGTH_FROM_FREQ(Prescale, Frequency) ((((F_CPU / (Prescale)) / (Frequency)) - 16) / 2)
|
|
|
|
/* Enums: */
|
|
/** Enum for the possible return codes of the TWI transfer start routine and other dependant TWI functions. */
|
|
enum TWI_ErrorCodes_t
|
|
{
|
|
TWI_ERROR_NoError = 0, /**< Indicates that the command completed successfully. */
|
|
TWI_ERROR_BusFault = 1, /**< A TWI bus fault occurred while attempting to capture the bus. */
|
|
TWI_ERROR_BusCaptureTimeout = 2, /**< A timeout occurred whilst waiting for the bus to be ready. */
|
|
TWI_ERROR_SlaveResponseTimeout = 3, /**< No ACK received at the nominated slave address within the timeout period. */
|
|
TWI_ERROR_SlaveNotReady = 4, /**< Slave NAKed the TWI bus START condition. */
|
|
TWI_ERROR_SlaveNAK = 5, /**< Slave NAKed whilst attempting to send data to the device. */
|
|
};
|
|
|
|
/* Inline Functions: */
|
|
/** Initializes the TWI hardware into master mode, ready for data transmission and reception. This must be
|
|
* before any other TWI operations.
|
|
*
|
|
* The generated SCL frequency will be according to the formula <pre>F_CPU / (16 + 2 * BitLength + 4 ^ Prescale)</pre>.
|
|
*
|
|
* \attention The value of the \c BitLength parameter should not be set below 10 or invalid bus conditions may
|
|
* occur, as indicated in the AVR8 microcontroller datasheet.
|
|
*
|
|
* \param[in] Prescale Prescaler to use when determining the bus frequency, a \c TWI_BIT_PRESCALE_* value.
|
|
* \param[in] BitLength Length of the bits sent on the bus.
|
|
*/
|
|
static inline void TWI_Init(const uint8_t Prescale,
|
|
const uint8_t BitLength) ATTR_ALWAYS_INLINE;
|
|
static inline void TWI_Init(const uint8_t Prescale,
|
|
const uint8_t BitLength)
|
|
{
|
|
TWCR |= (1 << TWEN);
|
|
TWSR = Prescale;
|
|
TWBR = BitLength;
|
|
}
|
|
|
|
/** Turns off the TWI driver hardware. If this is called, any further TWI operations will require a call to
|
|
* \ref TWI_Init() before the TWI can be used again.
|
|
*/
|
|
static inline void TWI_Disable(void) ATTR_ALWAYS_INLINE;
|
|
static inline void TWI_Disable(void)
|
|
{
|
|
TWCR &= ~(1 << TWEN);
|
|
}
|
|
|
|
/** Sends a TWI STOP onto the TWI bus, terminating communication with the currently addressed device. */
|
|
static inline void TWI_StopTransmission(void) ATTR_ALWAYS_INLINE;
|
|
static inline void TWI_StopTransmission(void)
|
|
{
|
|
TWCR = ((1 << TWINT) | (1 << TWSTO) | (1 << TWEN));
|
|
}
|
|
|
|
/* Function Prototypes: */
|
|
/** Begins a master mode TWI bus communication with the given slave device address.
|
|
*
|
|
* \param[in] SlaveAddress Address of the slave TWI device to communicate with.
|
|
* \param[in] TimeoutMS Timeout period within which the slave must respond, in milliseconds.
|
|
*
|
|
* \return A value from the \ref TWI_ErrorCodes_t enum.
|
|
*/
|
|
uint8_t TWI_StartTransmission(const uint8_t SlaveAddress,
|
|
const uint8_t TimeoutMS);
|
|
|
|
/** Sends a byte to the currently addressed device on the TWI bus.
|
|
*
|
|
* \param[in] Byte Byte to send to the currently addressed device
|
|
*
|
|
* \return Boolean \c true if the recipient ACKed the byte, \c false otherwise
|
|
*/
|
|
bool TWI_SendByte(const uint8_t Byte);
|
|
|
|
/** Receives a byte from the currently addressed device on the TWI bus.
|
|
*
|
|
* \param[in] Byte Location where the read byte is to be stored.
|
|
* \param[in] LastByte Indicates if the byte should be ACKed if false, NAKed if true.
|
|
*
|
|
* \return Boolean \c true if the byte reception successfully completed, \c false otherwise.
|
|
*/
|
|
bool TWI_ReceiveByte(uint8_t* const Byte,
|
|
const bool LastByte) ATTR_NON_NULL_PTR_ARG(1);
|
|
|
|
/** High level function to perform a complete packet transfer over the TWI bus to the specified
|
|
* device.
|
|
*
|
|
* \param[in] SlaveAddress Base address of the TWI slave device to communicate with.
|
|
* \param[in] TimeoutMS Timeout for bus capture and slave START ACK, in milliseconds.
|
|
* \param[in] InternalAddress Pointer to a location where the internal slave read start address is stored.
|
|
* \param[in] InternalAddressLen Size of the internal device address, in bytes.
|
|
* \param[in] Buffer Pointer to a buffer where the read packet data is to be stored.
|
|
* \param[in] Length Size of the packet to read, in bytes.
|
|
*
|
|
* \return A value from the \ref TWI_ErrorCodes_t enum.
|
|
*/
|
|
uint8_t TWI_ReadPacket(const uint8_t SlaveAddress,
|
|
const uint8_t TimeoutMS,
|
|
const uint8_t* InternalAddress,
|
|
uint8_t InternalAddressLen,
|
|
uint8_t* Buffer,
|
|
uint16_t Length) ATTR_NON_NULL_PTR_ARG(3);
|
|
|
|
/** High level function to perform a complete packet transfer over the TWI bus from the specified
|
|
* device.
|
|
*
|
|
* \param[in] SlaveAddress Base address of the TWI slave device to communicate with
|
|
* \param[in] TimeoutMS Timeout for bus capture and slave START ACK, in milliseconds
|
|
* \param[in] InternalAddress Pointer to a location where the internal slave write start address is stored
|
|
* \param[in] InternalAddressLen Size of the internal device address, in bytes
|
|
* \param[in] Buffer Pointer to a buffer where the packet data to send is stored
|
|
* \param[in] Length Size of the packet to send, in bytes
|
|
*
|
|
* \return A value from the \ref TWI_ErrorCodes_t enum.
|
|
*/
|
|
uint8_t TWI_WritePacket(const uint8_t SlaveAddress,
|
|
const uint8_t TimeoutMS,
|
|
const uint8_t* InternalAddress,
|
|
uint8_t InternalAddressLen,
|
|
const uint8_t* Buffer,
|
|
uint16_t Length) ATTR_NON_NULL_PTR_ARG(3);
|
|
|
|
/* Disable C linkage for C++ Compilers: */
|
|
#if defined(__cplusplus)
|
|
}
|
|
#endif
|
|
|
|
#endif
|
|
|
|
/** @} */
|
|
|