LUFA/Drivers/Peripheral/XMEGA/TWI_XMEGA.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2013.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2013  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaims all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *  \brief TWI Peripheral Driver (XMEGA)
  33  *
  34  *  On-chip TWI driver for the XMEGA Family of AVR microcontrollers.
  35  *
  36  *  \note This file should not be included directly. It is automatically included as needed by the TWI driver
  37  *        dispatch header located in LUFA/Drivers/Peripheral/TWI.h.
  38  */
  39
  40 /** \ingroup Group_TWI
  41  *  \defgroup Group_TWI_XMEGA TWI Peripheral Driver (XMEGA)
  42  *
  43  *  \section Sec_TWI_XMEGA_ModDescription Module Description
  44  *  Master mode TWI driver for the 8-bit AVR microcontrollers which contain a hardware TWI module.
  45  *
  46  *  \note This file should not be included directly. It is automatically included as needed by the TWI driver
  47  *        dispatch header located in LUFA/Drivers/Peripheral/TWI.h.
  48  *
  49  *  \section Sec_TWI_XMEGA_ExampleUsage Example Usage
  50  *  The following snippet is an example of how this module may be used within a typical
  51  *  application.
  52  *
  53  *  <b>Low Level API Example:</b>
  54  *  \code
  55  *      // Initialize the TWI driver before first use at 200KHz
  56  *      TWI_Init(&TWIC, TWI_BAUD_FROM_FREQ(200000));
  57  *
  58  *      // Start a write session to device at device address 0xA0, internal address 0xDC with a 10ms timeout
  59  *      if (TWI_StartTransmission(&TWIC, 0xA0 | TWI_ADDRESS_WRITE, 10) == TWI_ERROR_NoError)
  60  *      {
  61  *          TWI_SendByte(&TWIC, 0xDC);
  62  *
  63  *          TWI_SendByte(&TWIC, 0x01);
  64  *          TWI_SendByte(&TWIC, 0x02);
  65  *          TWI_SendByte(&TWIC, 0x03);
  66  *
  67  *          // Must stop transmission afterwards to release the bus
  68  *          TWI_StopTransmission(&TWIC);
  69  *      }
  70  *
  71  *      // Start a read session to device at address 0xA0, internal address 0xDC with a 10ms timeout
  72  *      if (TWI_StartTransmission(&TWIC, 0xA0 | TWI_ADDRESS_WRITE, 10) == TWI_ERROR_NoError)
  73  *      {
  74  *          TWI_SendByte(&TWIC, 0xDC);
  75  *          TWI_StopTransmission(&TWIC);
  76  *
  77  *          if (TWI_StartTransmission(&TWIC, 0xA0 | TWI_ADDRESS_READ, 10) == TWI_ERROR_NoError)
  78  *          {
  79  *              uint8_t Byte1, Byte2, Byte3;
  80  *
  81  *              // Read three bytes, acknowledge after the third byte is received
  82  *              TWI_ReceiveByte(&TWIC, &Byte1, false);
  83  *              TWI_ReceiveByte(&TWIC, &Byte2, false);
  84  *              TWI_ReceiveByte(&TWIC, &Byte3, true);
  85  *
  86  *              // Must stop transmission afterwards to release the bus
  87  *              TWI_StopTransmission(&TWIC);
  88  *          }
  89  *      }
  90  *  \endcode
  91  *
  92  *  <b>High Level API Example:</b>
  93  *  \code
  94  *      // Initialize the TWI driver before first use at 200KHz
  95  *      TWI_Init(&TWIC, TWI_BAUD_FROM_FREQ(200000));
  96  *
  97  *      // Start a write session to device at device address 0xA0, internal address 0xDC with a 10ms timeout
  98  *      uint8_t InternalWriteAddress = 0xDC;
  99  *      uint8_t WritePacket[3] = {0x01, 0x02, 0x03};
 100  *
 101  *      TWI_WritePacket(&TWIC, 0xA0, 10, &InternalWriteAddress, sizeof(InternalWriteAddress),
 102  *                      &WritePacket, sizeof(WritePacket);
 103  *
 104  *      // Start a read session to device at address 0xA0, internal address 0xDC with a 10ms timeout
 105  *      uint8_t InternalReadAddress = 0xDC;
 106  *      uint8_t ReadPacket[3];
 107  *
 108  *      TWI_ReadPacket(&TWIC, 0xA0, 10, &InternalReadAddress, sizeof(InternalReadAddress),
 109  *                     &ReadPacket, sizeof(ReadPacket);
 110  *  \endcode
 111  *
 112  *  @{
 113  */
 114
 115 #ifndef __TWI_XMEGA_H__
 116 #define __TWI_XMEGA_H__
 117
 118         /* Includes: */
 119                 #include "../../../Common/Common.h"
 120
 121                 #include <stdio.h>
 122
 123         /* Enable C linkage for C++ Compilers: */
 124                 #if defined(__cplusplus)
 125                         extern "C" {
 126                 #endif
 127
 128         /* Preprocessor Checks: */
 129                 #if !defined(__INCLUDE_FROM_TWI_H) && !defined(__INCLUDE_FROM_TWI_C)
 130                         #error Do not include this file directly. Include LUFA/Drivers/Peripheral/TWI.h instead.
 131                 #endif
 132
 133         /* Public Interface - May be used in end-application: */
 134                 /* Macros: */
 135                         /** TWI slave device address mask for a read session. Mask with a slave device base address to obtain
 136                          *  the correct TWI bus address for the slave device when reading data from it.
 137                          */
 138                         #define TWI_ADDRESS_READ         0x01
 139
 140                         /** TWI slave device address mask for a write session. Mask with a slave device base address to obtain
 141                          *  the correct TWI bus address for the slave device when writing data to it.
 142                          */
 143                         #define TWI_ADDRESS_WRITE        0x00
 144
 145                         /** Mask to retrieve the base address for a TWI device, which can then be ORed with \ref TWI_ADDRESS_READ
 146                          *  or \ref TWI_ADDRESS_WRITE to obtain the device's read and write address respectively.
 147                          */
 148                         #define TWI_DEVICE_ADDRESS_MASK  0xFE
 149
 150                         /** Calculates the length of each bit on the TWI bus for a given target frequency. This may be used with
 151                          *  the \ref TWI_Init() function to convert a bus frequency to a number of clocks for the \c BitLength
 152                          *  parameter.
 153                          *
 154                          *  \param[in] Frequency  Desired TWI bus frequency in Hz.
 155                          *
 156                          *  \return Bit length in clocks for the given TWI bus frequency at the given prescaler value.
 157                          */
 158                         #define TWI_BAUD_FROM_FREQ(Frequency) ((F_CPU / (2 * Frequency)) - 5)
 159
 160                 /* Enums: */
 161                         /** Enum for the possible return codes of the TWI transfer start routine and other dependant TWI functions. */
 162                         enum TWI_ErrorCodes_t
 163                         {
 164                                 TWI_ERROR_NoError              = 0, /**< Indicates that the command completed successfully. */
 165                                 TWI_ERROR_BusFault             = 1, /**< A TWI bus fault occurred while attempting to capture the bus. */
 166                                 TWI_ERROR_BusCaptureTimeout    = 2, /**< A timeout occurred whilst waiting for the bus to be ready. */
 167                                 TWI_ERROR_SlaveResponseTimeout = 3, /**< No ACK received at the nominated slave address within the timeout period. */
 168                                 TWI_ERROR_SlaveNotReady        = 4, /**< Slave NAKed the TWI bus START condition. */
 169                                 TWI_ERROR_SlaveNAK             = 5, /**< Slave NAKed whilst attempting to send data to the device. */
 170                         };
 171
 172                 /* Inline Functions: */
 173                         /** Initializes the TWI hardware into master mode, ready for data transmission and reception. This must be
 174                          *  before any other TWI operations.
 175                          *
 176                          *  The generated SCL frequency will be according to the formula <pre>F_CPU / (2 * (5 + (BAUD)))</pre>.
 177                          *
 178                          *  \attention The value of the \c BitLength parameter should not be set below 10 or invalid bus conditions may
 179                          *             occur, as indicated in the XMEGA microcontroller datasheet.
 180                          *
 181        *  \param[in] twi        The TWI Peripheral to use
 182                          *  \param[in] Baud       Value of the BAUD register of the TWI Master.
 183                          */
 184                         static inline void TWI_Init(TWI_t *twi, const uint8_t Baud) ATTR_ALWAYS_INLINE;
 185                         static inline void TWI_Init(TWI_t *twi, const uint8_t Baud)
 186                         {
 187         twi->BAUD = Baud;
 188         twi->CTRLA |= TWI_MASTER_ENABLE_bm;
 189                         }
 190
 191                         /** Turns off the TWI driver hardware. If this is called, any further TWI operations will require a call to
 192                          *  \ref TWI_Init() before the TWI can be used again.
 193        *
 194        *  \param[in] twi        The TWI Peripheral to use
 195                          */
 196                         static inline void TWI_Disable(TWI_t *twi) ATTR_ALWAYS_INLINE;
 197                         static inline void TWI_Disable(TWI_t *twi)
 198                         {
 199         twi->CTRLA &= ~TWI_MASTER_ENABLE_bm;
 200                         }
 201
 202                         /** Sends a TWI STOP onto the TWI bus, terminating communication with the currently addressed device.
 203        *
 204        *  \param[in] twi        The TWI Peripheral to use
 205        */
 206                         static inline void TWI_StopTransmission(TWI_t *twi) ATTR_ALWAYS_INLINE;
 207                         static inline void TWI_StopTransmission(TWI_t *twi)
 208                         {
 209         twi->CTRLC = TWI_MASTER_CMD_STOP_gc;
 210                         }
 211
 212                 /* Function Prototypes: */
 213                         /** Begins a master mode TWI bus communication with the given slave device address.
 214                          *
 215        *  \param[in] twi                 The TWI Peripheral to use
 216                          *  \param[in] SlaveAddress  Address of the slave TWI device to communicate with.
 217                          *  \param[in] TimeoutMS     Timeout period within which the slave must respond, in milliseconds.
 218                          *
 219                          *  \return A value from the \ref TWI_ErrorCodes_t enum.
 220                          */
 221                         uint8_t TWI_StartTransmission(TWI_t *twi,
 222                                     const uint8_t SlaveAddress,
 223                                                       const uint8_t TimeoutMS);
 224
 225                         /** Sends a byte to the currently addressed device on the TWI bus.
 226                          *
 227        *  \param[in] twi                 The TWI Peripheral to use
 228                          *  \param[in] Byte  Byte to send to the currently addressed device
 229                          *
 230                          *  \return Boolean \c true if the recipient ACKed the byte, \c false otherwise
 231                          */
 232                         bool TWI_SendByte(TWI_t *twi, const uint8_t Byte);
 233
 234                         /** Receives a byte from the currently addressed device on the TWI bus.
 235                          *
 236        *  \param[in] twi                 The TWI Peripheral to use
 237                          *  \param[in] Byte      Location where the read byte is to be stored.
 238                          *  \param[in] LastByte  Indicates if the byte should be ACKed if false, NAKed if true.
 239                          *
 240                          *  \return Boolean \c true if the byte reception successfully completed, \c false otherwise.
 241                          */
 242                         bool TWI_ReceiveByte(TWI_t *twi, uint8_t* const Byte,
 243                                              const bool LastByte) ATTR_NON_NULL_PTR_ARG(1);
 244
 245                         /** High level function to perform a complete packet transfer over the TWI bus to the specified
 246                          *  device.
 247                          *
 248        *  \param[in] twi                 The TWI Peripheral to use
 249                          *  \param[in] SlaveAddress        Base address of the TWI slave device to communicate with.
 250                          *  \param[in] TimeoutMS           Timeout for bus capture and slave START ACK, in milliseconds.
 251                          *  \param[in] InternalAddress     Pointer to a location where the internal slave read start address is stored.
 252                          *  \param[in] InternalAddressLen  Size of the internal device address, in bytes.
 253                          *  \param[in] Buffer              Pointer to a buffer where the read packet data is to be stored.
 254                          *  \param[in] Length              Size of the packet to read, in bytes.
 255                          *
 256                          *  \return A value from the \ref TWI_ErrorCodes_t enum.
 257                          */
 258                         uint8_t TWI_ReadPacket(TWI_t *twi,
 259                              const uint8_t SlaveAddress,
 260                                                const uint8_t TimeoutMS,
 261                                                const uint8_t* InternalAddress,
 262                                                uint8_t InternalAddressLen,
 263                                                uint8_t* Buffer,
 264                                                uint8_t Length) ATTR_NON_NULL_PTR_ARG(3);
 265
 266                         /** High level function to perform a complete packet transfer over the TWI bus from the specified
 267                          *  device.
 268                          *
 269        *  \param[in] twi                 The TWI Peripheral to use
 270                          *  \param[in] SlaveAddress        Base address of the TWI slave device to communicate with
 271                          *  \param[in] TimeoutMS           Timeout for bus capture and slave START ACK, in milliseconds
 272                          *  \param[in] InternalAddress     Pointer to a location where the internal slave write start address is stored
 273                          *  \param[in] InternalAddressLen  Size of the internal device address, in bytes
 274                          *  \param[in] Buffer              Pointer to a buffer where the packet data to send is stored
 275                          *  \param[in] Length              Size of the packet to send, in bytes
 276                          *
 277                          *  \return A value from the \ref TWI_ErrorCodes_t enum.
 278                          */
 279                         uint8_t TWI_WritePacket(TWI_t *twi,
 280                               const uint8_t SlaveAddress,
 281                                                 const uint8_t TimeoutMS,
 282                                                 const uint8_t* InternalAddress,
 283                                                 uint8_t InternalAddressLen,
 284                                                 const uint8_t* Buffer,
 285                                                 uint8_t Length) ATTR_NON_NULL_PTR_ARG(3);
 286
 287         /* Disable C linkage for C++ Compilers: */
 288                 #if defined(__cplusplus)
 289                         }
 290                 #endif
 291
 292 #endif
 293
 294 /** @} */
 295