include/spi.h

   1 /*
   2  * (C) Copyright 2009,2014 Leo C. <erbl259-lmu@yahoo.de>
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #ifndef SPI_H_
   8 #define SPI_H_
   9
  10 #define SPI_PORT        PORTB           /* SPI Connection port */
  11 #define SPI_DDR         DDRB            /* SPI Direction port */
  12 #define SPI_SS          0
  13 #define SPI_SCK         1
  14 #define SPI_MOSI        2
  15 #define SPI_MISO        3
  16
  17
  18 /* SPI macros */
  19
  20 #define SPI_SET_SPEED_F_2               do {SPCR = (1<<SPE) | (1<<MSTR) | (0<<SPR1) | (0<<SPR0); SPSR = (1<<SPI2X); } while(0)
  21 #define SPI_SET_SPEED_F_4               do {SPCR = (1<<SPE) | (1<<MSTR) | (0<<SPR1) | (0<<SPR0); SPSR = (0<<SPI2X); } while(0)
  22 #define SPI_SET_SPEED_F_8               do {SPCR = (1<<SPE) | (1<<MSTR) | (0<<SPR1) | (1<<SPR0); SPSR = (1<<SPI2X); } while(0)
  23 #define SPI_SET_SPEED_F_16              do {SPCR = (1<<SPE) | (1<<MSTR) | (0<<SPR1) | (1<<SPR0); SPSR = (0<<SPI2X); } while(0)
  24 #define SPI_SET_SPEED_F_32              do {SPCR = (1<<SPE) | (1<<MSTR) | (1<<SPR1) | (0<<SPR0); SPSR = (1<<SPI2X); } while(0)
  25 #define SPI_SET_SPEED_F_64              do {SPCR = (1<<SPE) | (1<<MSTR) | (1<<SPR1) | (0<<SPR0); SPSR = (0<<SPI2X); } while(0)
  26 #define SPI_SET_SPEED_F_128             do {SPCR = (1<<SPE) | (1<<MSTR) | (1<<SPR1) | (1<<SPR0); SPSR = (0<<SPI2X); } while(0)
  27
  28 /** switch to fast SPI Clock */
  29 #define SPISetFastClock()               SPI_SET_SPEED_F_2
  30 #define SPISetSlowClock()               SPI_SET_SPEED_F_8
  31 #define SPISetMMCInitClock()    SPI_SET_SPEED_F_64
  32
  33 #define SPI_OFF()                               do { SPCR = 0; } while(0)
  34
  35 static inline __attribute__((always_inline)) void spi_wait() {
  36         loop_until_bit_is_set(SPSR,SPIF);
  37 }
  38
  39 static inline __attribute__((always_inline)) void spi_write(uint8_t a) {
  40         SPDR = a;
  41 }
  42
  43 static inline void spi_xmit(uint8_t a){
  44         spi_write(a);
  45         spi_wait();
  46 }
  47
  48 static inline uint8_t spi_rcvr(void) {
  49         SPDR = 0xFF;
  50         spi_wait();
  51         return SPDR;
  52 }
  53
  54 #endif /* SPI_H_ */