LUFA/Drivers/Peripheral/AVR32/SPI.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  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  *
  33  *  SPI driver for the 32-bit AVRs.
  34  *
  35  *  \note This file should not be included directly. It is automatically included as needed by the SPI driver
  36  *        dispatch header located in LUFA/Drivers/Peripheral/SPI.h.
  37  */
  38
  39 /** \ingroup Group_SPI
  40  *  @defgroup Group_SPI_AVR32 32-Bit AVR SPI Driver
  41  *
  42  *  SPI driver for the 32-bit AVRs.
  43  *
  44  *  \note This file should not be included directly. It is automatically included as needed by the ADC driver
  45  *        dispatch header located in LUFA/Drivers/Peripheral/SPI.h.
  46  *
  47  *  @{
  48  */
  49
  50 #ifndef __SPI_AVR32_H__
  51 #define __SPI_AVR32_H__
  52
  53         /* Includes: */
  54                 #include <avr32/io.h>
  55                 #include <stdbool.h>
  56
  57         /* Preprocessor Checks: */
  58                 #if !defined(__INCLUDE_FROM_SPI_H)
  59                         #error Do not include this file directly. Include LUFA/Drivers/Peripheral/SPI.h instead.
  60                 #endif
  61
  62         /* Enable C linkage for C++ Compilers: */
  63                 #if defined(__cplusplus)
  64                         extern "C" {
  65                 #endif
  66
  67         /* Public Interface - May be used in end-application: */
  68                 /* Macros: */
  69                         /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 1. */
  70                         #define SPI_SPEED_FCPU_DIV_1           0
  71
  72                         /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 32. */
  73                         #define SPI_SPEED_FCPU_DIV_32          AVR32_SPI_MR_FDIV_MASK
  74
  75                         /** SPI mode mask for SPI_Init(). Indicates that the SPI interface should be initialized into slave mode. */
  76                         #define SPI_MODE_SLAVE                 0
  77
  78                         /** SPI mode mask for SPI_Init(). Indicates that the SPI interface should be initialized into master mode. */
  79                         #define SPI_MODE_MASTER                AVR32_SPI_MR_MSTR_MASK
  80
  81                 /* Inline Functions: */
  82                         /** Initialises the SPI subsystem, ready for transfers. Must be called before calling any other
  83                          *  SPI routines.
  84                          *
  85                          *  \note The individual AVR32 chip select control registers are left at their defaults; it is up to the user
  86                          *        to configure these seperately once the SPI module has been initialized.
  87                          *
  88                          *  \note The physical GPIO pins for the AVR32's SPI are not altered; it is up to the user to
  89                          *        configure these seperately to connect the SPI module to the desired GPIO pins via the
  90                          *        GPIO MUX registers.
  91                          *
  92                          *  \param[in] SPIOptions  SPI Options, a mask consisting of one of each of the SPI_SPEED_*
  93                          *                         and SPI_MODE_* masks
  94                          */
  95                         static inline void SPI_Init(const uintN_t SPIOptions)
  96                         {
  97                                 AVR32_SPI.cr = (AVR32_SPI_CR_SPIEN_MASK | AVR32_SPI_CR_SWRST_MASK);
  98                                 AVR32_SPI.mr = SPIOptions;
  99                         }
 100
 101                         /** Turns off the SPI driver, disabling and returning used hardware to their default configuration. */
 102                         static inline void SPI_ShutDown(void)
 103                         {
 104                                 AVR32_SPI.cr = AVR32_SPI_CR_SPIDIS_MASK;
 105                         }
 106
 107                         /** Sends and receives a transfer through the SPI interface, blocking until the transfer is complete.
 108                          *  The width of the data that is transferred is dependant on the settings of the currently selected
 109                          *  peripheral.
 110                          *
 111                          *  \param[in] Data  Data to send through the SPI interface
 112                          *
 113                          *  \return Response data from the attached SPI device
 114                          */
 115                         static inline uint16_t SPI_Transfer(const uint16_t Data) ATTR_ALWAYS_INLINE;
 116                         static inline uint16_t SPI_Transfer(const uint16_t Data)
 117                         {
 118                                 AVR32_SPI.TDR.td = Data;
 119                                 while (!(AVR32_SPI.SR.tdre));
 120                                 return AVR32_SPI.rdr;
 121                         }
 122
 123                         /** Sends a transfer through the SPI interface, blocking until the transfer is complete. The response
 124                          *  data sent to from the attached SPI device is ignored. The width of the data that is transferred is
 125                          *  dependant on the settings of the currently selected peripheral.
 126                          *
 127                          *  \param[in] Data  Data to send through the SPI interface
 128                          */
 129                         static inline void SPI_Send(const uint16_t Data) ATTR_ALWAYS_INLINE;
 130                         static inline void SPI_Send(const uint16_t Data)
 131                         {
 132                                 AVR32_SPI.TDR.td = Data;
 133                                 while (!(AVR32_SPI.SR.tdre));
 134                         }
 135
 136                         /** Sends a dummy transfer through the SPI interface, blocking until the transfer is complete. The response
 137                          *  data from the attached SPI device is returned. The width of the data that is transferred is dependant on
 138                          *  the settings of the currently selected peripheral.
 139                          *
 140                          *  \return The response data from the attached SPI device
 141                          */
 142                         static inline uint16_t SPI_Receive(void) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT;
 143                         static inline uint16_t SPI_Receive(void)
 144                         {
 145                                 AVR32_SPI.TDR.td = 0x0000;
 146                                 while (!(AVR32_SPI.SR.tdre));
 147                                 return AVR32_SPI.RDR.rd;
 148                         }
 149
 150         /* Disable C linkage for C++ Compilers: */
 151                 #if defined(__cplusplus)
 152                         }
 153                 #endif
 154
 155 #endif
 156
 157 /** @} */