--- /dev/null
+/*
+ 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
+
+/** @} */
+
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