LUFA/Drivers/Peripheral/XMEGA/SPI_XMEGA.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2012.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2012  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 disclaim 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 SPI Peripheral Driver (XMEGA)
  33  *
  34  *  On-chip SPI driver for the XMEGA microcontrollers.
  35  *
  36  *  \note This file should not be included directly. It is automatically included as needed by the SPI driver
  37  *        dispatch header located in LUFA/Drivers/Peripheral/SPI.h.
  38  */
  39
  40 /** \ingroup Group_SPI
  41  *  \defgroup Group_SPI_XMEGA SPI Peripheral Driver (XMEGA)
  42  *
  43  *  \section Sec_ModDescription Module Description
  44  *  Driver for the hardware SPI port(s) available on XMEGA AVR microcontroller models. This
  45  *  module provides an easy to use driver for the setup and transfer of data over the AVR's
  46  *  SPI ports.
  47  *
  48  *  \note This file should not be included directly. It is automatically included as needed by the SPI driver
  49  *        dispatch header located in LUFA/Drivers/Peripheral/SPI.h.
  50  *
  51  *  \code
  52  *      // Initialize the SPI driver before first use
  53  *      SPI_Init(&SPIC,
  54  *               SPI_SPEED_FCPU_DIV_2 | SPI_ORDER_MSB_FIRST | SPI_SCK_LEAD_FALLING |
  55  *               SPI_SAMPLE_TRAILING | SPI_MODE_MASTER);
  56  *
  57  *      // Send several bytes, ignoring the returned data
  58  *      SPI_SendByte(&SPIC, 0x01);
  59  *      SPI_SendByte(&SPIC, 0x02);
  60  *      SPI_SendByte(&SPIC, 0x03);
  61  *
  62  *      // Receive several bytes, sending a dummy 0x00 byte each time
  63  *      uint8_t Byte1 = SPI_ReceiveByte(&SPIC);
  64  *      uint8_t Byte2 = SPI_ReceiveByte(&SPIC);
  65  *      uint8_t Byte3 = SPI_ReceiveByte(&SPIC);
  66  *
  67  *      // Send a byte, and store the received byte from the same transaction
  68  *      uint8_t ResponseByte = SPI_TransferByte(&SPIC, 0xDC);
  69  *  \endcode
  70  *
  71  *  @{
  72  */
  73
  74 #ifndef __SPI_XMEGA_H__
  75 #define __SPI_XMEGA_H__
  76
  77         /* Includes: */
  78                 #include "../../../Common/Common.h"
  79
  80         /* Enable C linkage for C++ Compilers: */
  81                 #if defined(__cplusplus)
  82                         extern "C" {
  83                 #endif
  84
  85         /* Preprocessor Checks: */
  86                 #if !defined(__INCLUDE_FROM_SPI_H)
  87                         #error Do not include this file directly. Include LUFA/Drivers/Peripheral/SPI.h instead.
  88                 #endif
  89
  90         /* Private Interface - For use in library only: */
  91         #if !defined(__DOXYGEN__)
  92                 /* Macros: */
  93                         #define SPI_USE_DOUBLESPEED            SPI_CLK2X_bm
  94         #endif
  95
  96         /* Public Interface - May be used in end-application: */
  97                 /* Macros: */
  98                         /** \name SPI Prescaler Configuration Masks */
  99                         //@{
 100                         /** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 2. */
 101                         #define SPI_SPEED_FCPU_DIV_2           SPI_USE_DOUBLESPEED
 102
 103                         /** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 4. */
 104                         #define SPI_SPEED_FCPU_DIV_4           0
 105
 106                         /** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 8. */
 107                         #define SPI_SPEED_FCPU_DIV_8           (SPI_USE_DOUBLESPEED | (1 << SPI_PRESCALER_gp))
 108
 109                         /** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 16. */
 110                         #define SPI_SPEED_FCPU_DIV_16          (1 << SPI_PRESCALER_gp)
 111
 112                         /** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 32. */
 113                         #define SPI_SPEED_FCPU_DIV_32          (SPI_USE_DOUBLESPEED | (2 << SPI_PRESCALER_gp))
 114
 115                         /** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 64. */
 116                         #define SPI_SPEED_FCPU_DIV_64          (2 << SPI_PRESCALER_gp)
 117
 118                         /** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 128. */
 119                         #define SPI_SPEED_FCPU_DIV_128         (3 << SPI_PRESCALER_gp)
 120                         //@}
 121
 122                         /** \name SPI SCK Polarity Configuration Masks */
 123                         //@{
 124                         /** SPI clock polarity mask for \ref SPI_Init(). Indicates that the SCK should lead on the rising edge. */
 125                         #define SPI_SCK_LEAD_RISING            0
 126
 127                         /** SPI clock polarity mask for \ref SPI_Init(). Indicates that the SCK should lead on the falling edge. */
 128                         #define SPI_SCK_LEAD_FALLING           SPI_MODE1_bm
 129                         //@}
 130
 131                         /** \name SPI Sample Edge Configuration Masks */
 132                         //@{
 133                         /** SPI data sample mode mask for \ref SPI_Init(). Indicates that the data should sampled on the leading edge. */
 134                         #define SPI_SAMPLE_LEADING             0
 135
 136                         /** SPI data sample mode mask for \ref SPI_Init(). Indicates that the data should be sampled on the trailing edge. */
 137                         #define SPI_SAMPLE_TRAILING            SPI_MODE0_bm
 138                         //@}
 139
 140                         /** \name SPI Data Ordering Configuration Masks */
 141                         //@{
 142                         /** SPI data order mask for \ref SPI_Init(). Indicates that data should be shifted out MSB first. */
 143                         #define SPI_ORDER_MSB_FIRST            0
 144
 145                         /** SPI data order mask for \ref SPI_Init(). Indicates that data should be shifted out LSB first. */
 146                         #define SPI_ORDER_LSB_FIRST            SPI_DORD_bm
 147                         //@}
 148
 149                         /** \name SPI Mode Configuration Masks */
 150                         //@{
 151                         /** SPI mode mask for \ref SPI_Init(). Indicates that the SPI interface should be initialized into slave mode. */
 152                         #define SPI_MODE_SLAVE                 0
 153
 154                         /** SPI mode mask for \ref SPI_Init(). Indicates that the SPI interface should be initialized into master mode. */
 155                         #define SPI_MODE_MASTER                SPI_MASTER_bm
 156                         //@}
 157
 158                 /* Inline Functions: */
 159                         /** Initializes the SPI subsystem, ready for transfers. Must be called before calling any other
 160                          *  SPI routines.
 161                          *
 162                          *  \param[in,out] SPI         Pointer to the base of the SPI peripheral within the device.
 163                          *  \param[in]     SPIOptions  SPI Options, a mask consisting of one of each of the \c SPI_SPEED_*,
 164                          *                             \c SPI_SCK_*, \c SPI_SAMPLE_*, \c SPI_ORDER_* and \c SPI_MODE_* masks.
 165                          */
 166                         static inline void SPI_Init(SPI_t* const SPI,
 167                                                     const uint8_t SPIOptions)
 168                         {
 169                                 SPI->CTRL = (SPIOptions | SPI_ENABLE_bm);
 170                         }
 171
 172                         /** Turns off the SPI driver, disabling and returning used hardware to their default configuration.
 173                          *
 174                          *  \param[in,out] SPI   Pointer to the base of the SPI peripheral within the device.
 175                          */
 176                         static inline void SPI_Disable(SPI_t* const SPI)
 177                         {
 178                                 SPI->CTRL &= ~SPI_ENABLE_bm;
 179                         }
 180
 181                         /** Retrieves the currently selected SPI mode, once the SPI interface has been configured.
 182                          *
 183                          *  \param[in,out] SPI  Pointer to the base of the SPI peripheral within the device.
 184                          *
 185                          *  \return \ref SPI_MODE_MASTER if the interface is currently in SPI Master mode, \ref SPI_MODE_SLAVE otherwise
 186                          */
 187                         static inline uint8_t SPI_GetCurrentMode(SPI_t* const SPI) ATTR_ALWAYS_INLINE;
 188                         static inline uint8_t SPI_GetCurrentMode(SPI_t* const SPI)
 189                         {
 190                                 return (SPI->CTRL & SPI_MASTER_bm);
 191                         }
 192
 193                         /** Sends and receives a byte through the SPI interface, blocking until the transfer is complete.
 194                          *
 195                          *  \param[in,out] SPI   Pointer to the base of the SPI peripheral within the device.
 196                          *  \param[in]     Byte  Byte to send through the SPI interface.
 197                          *
 198                          *  \return Response byte from the attached SPI device.
 199                          */
 200                         static inline uint8_t SPI_TransferByte(SPI_t* const SPI,
 201                                                                const uint8_t Byte) ATTR_ALWAYS_INLINE;
 202                         static inline uint8_t SPI_TransferByte(SPI_t* const SPI,
 203                                                                const uint8_t Byte)
 204                         {
 205                                 SPI->DATA = Byte;
 206                                 while (!(SPI->STATUS & SPI_IF_bm));
 207                                 return SPI->DATA;
 208                         }
 209
 210                         /** Sends a byte through the SPI interface, blocking until the transfer is complete. The response
 211                          *  byte sent to from the attached SPI device is ignored.
 212                          *
 213                          *  \param[in,out] SPI   Pointer to the base of the SPI peripheral within the device.
 214                          *  \param[in]     Byte  Byte to send through the SPI interface.
 215                          */
 216                         static inline void SPI_SendByte(SPI_t* const SPI,
 217                                                         const uint8_t Byte) ATTR_ALWAYS_INLINE;
 218                         static inline void SPI_SendByte(SPI_t* const SPI,
 219                                                         const uint8_t Byte)
 220                         {
 221                                 SPI->DATA = Byte;
 222                                 while (!(SPI->STATUS & SPI_IF_bm));
 223                         }
 224
 225                         /** Sends a dummy byte through the SPI interface, blocking until the transfer is complete. The response
 226                          *  byte from the attached SPI device is returned.
 227                          *
 228                          *  \param[in,out] SPI  Pointer to the base of the SPI peripheral within the device.
 229                          *
 230                          *  \return The response byte from the attached SPI device.
 231                          */
 232                         static inline uint8_t SPI_ReceiveByte(SPI_t* const SPI) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT;
 233                         static inline uint8_t SPI_ReceiveByte(SPI_t* const SPI)
 234                         {
 235                                 SPI->DATA = 0;
 236                                 while (!(SPI->STATUS & SPI_IF_bm));
 237                                 return SPI->DATA;
 238                         }
 239
 240         /* Disable C linkage for C++ Compilers: */
 241                 #if defined(__cplusplus)
 242                         }
 243                 #endif
 244
 245 #endif
 246
 247 /** @} */
 248