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Diffstat (limited to 'lib/lufa/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h')
| -rw-r--r-- | lib/lufa/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/lib/lufa/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h b/lib/lufa/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h new file mode 100644 index 0000000000..a8b845a5d7 --- /dev/null +++ b/lib/lufa/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h @@ -0,0 +1,305 @@ +/* + 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 + +/** @} */ + |