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 chip selection mode for direct peripheral-to-CS pin connections. */
  76                         #define SPI_CS_4BITDECODER             AVR32_SPI_MR_PSDEC_MASK
  77
  78                         /** SPI chip selection mode for peripheral CS pin connections through a 4-bit decoder. */
  79                         #define SPI_CS_DIRECT                  0
  80
  81                         /** SPI mode mask for SPI_Init(). Indicates that the SPI interface should be initialized into slave mode. */
  82                         #define SPI_MODE_SLAVE                 0
  83
  84                         /** SPI mode mask for SPI_Init(). Indicates that the SPI interface should be initialized into master mode. */
  85                         #define SPI_MODE_MASTER                AVR32_SPI_MR_MSTR_MASK
  86
  87                 /* Inline Functions: */
  88                         /** Initialises the SPI subsystem, ready for transfers. Must be called before calling any other
  89                          *  SPI routines.
  90                          *
  91                          *  \note The individual AVR32 chip select control registers are left at their defaults; it is up to the user
  92                          *        to configure these seperately once the SPI module has been initialized.
  93                          *
  94                          *  \note The physical GPIO pins for the AVR32's SPI are not altered; it is up to the user to
  95                          *        configure these seperately to connect the SPI module to the desired GPIO pins via the
  96                          *        GPIO MUX registers.
  97                          *
  98                          *  \param[in] SPIOptions  SPI Options, a mask consisting of one of each of the SPI_SPEED_*,
  99                          *                         SPI_CS_* and SPI_MODE_* masks
 100                          */
 101                         static inline void SPI_Init(const uintN_t SPIOptions)
 102                         {
 103                                 AVR32_PM.pbamask = (1 << 5);
 104
 105                                 AVR32_SPI.CR.swrst = true;
 106                                 AVR32_SPI.CR.spien = true;
 107                                 AVR32_SPI.mr = SPIOptions;
 108                         }
 109
 110                         /** Turns off the SPI driver, disabling and returning used hardware to their default configuration. */
 111                         static inline void SPI_ShutDown(void)
 112                         {
 113                                 AVR32_SPI.cr = AVR32_SPI_CR_SPIDIS_MASK;
 114
 115                                 AVR32_PM.pbamask &= ~(1 << 5);
 116                         }
 117
 118                         /** Sends and receives a transfer through the SPI interface, blocking until the transfer is complete.
 119                          *  The width of the data that is transferred is dependant on the settings of the currently selected
 120                          *  peripheral.
 121                          *
 122                          *  \param[in] Data  Data to send through the SPI interface
 123                          *
 124                          *  \return Response data from the attached SPI device
 125                          */
 126                         static inline uint16_t SPI_Transfer(const uint16_t Data) ATTR_ALWAYS_INLINE;
 127                         static inline uint16_t SPI_Transfer(const uint16_t Data)
 128                         {
 129                                 while (!(AVR32_SPI.SR.tdre));
 130                                 AVR32_SPI.TDR.td = Data;
 131
 132                                 while ((AVR32_SPI.sr & (AVR32_SPI_SR_RDRF_MASK | AVR32_SPI_SR_TXEMPTY_MASK)) !=
 133                                                        (AVR32_SPI_SR_RDRF_MASK | AVR32_SPI_SR_TXEMPTY_MASK));
 134                                 return AVR32_SPI.RDR.rd;
 135                         }
 136
 137                         /** Sends a transfer through the SPI interface, blocking until the transfer is complete. The response
 138                          *  data sent to from the attached SPI device is ignored. The width of the data that is transferred is
 139                          *  dependant on the settings of the currently selected peripheral.
 140                          *
 141                          *  \param[in] Data  Data to send through the SPI interface
 142                          */
 143                         static inline void SPI_Send(const uint16_t Data) ATTR_ALWAYS_INLINE;
 144                         static inline void SPI_Send(const uint16_t Data)
 145                         {
 146                                 while (!(AVR32_SPI.SR.tdre));
 147                                 AVR32_SPI.TDR.td = Data;
 148                         }
 149
 150                         /** Sends a dummy transfer through the SPI interface, blocking until the transfer is complete. The response
 151                          *  data from the attached SPI device is returned. The width of the data that is transferred is dependant on
 152                          *  the settings of the currently selected peripheral.
 153                          *
 154                          *  \return The response data from the attached SPI device
 155                          */
 156                         static inline uint16_t SPI_Receive(void) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT;
 157                         static inline uint16_t SPI_Receive(void)
 158                         {
 159                                 while (!(AVR32_SPI.SR.tdre));
 160                                 AVR32_SPI.TDR.td = 0x0000;
 161
 162                                 while ((AVR32_SPI.sr & (AVR32_SPI_SR_RDRF_MASK | AVR32_SPI_SR_TXEMPTY_MASK)) !=
 163                                                        (AVR32_SPI_SR_RDRF_MASK | AVR32_SPI_SR_TXEMPTY_MASK));
 164                                 return AVR32_SPI.RDR.rd;
 165                         }
 166
 167         /* Disable C linkage for C++ Compilers: */
 168                 #if defined(__cplusplus)
 169                         }
 170                 #endif
 171
 172 #endif
 173
 174 /** @} */