ARM: split out spi-avr.c from spi.c

This commit is contained in:
Nico Tonnhofer 2016-09-17 21:23:47 +02:00
parent d9a350749d
commit 7223c9dea8
2 changed files with 43 additions and 28 deletions

36
spi-avr.c Normal file
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@ -0,0 +1,36 @@
/** \file
\brief SPI routines, AVR specific part.
*/
#if defined TEACUP_C_INCLUDE && defined __AVR__
/** Initialise SPI subsystem.
Code copied from ATmega164/324/644/1284 data sheet, section 18.2, page 160,
or moved here from mendel.c.
*/
void spi_init() {
// Set SCK (clock) and MOSI line to output, ie. set USART in master mode.
SET_OUTPUT(SCK);
SET_OUTPUT(MOSI);
SET_INPUT(MISO);
// SS must be set as output to disconnect it from the SPI subsystem.
// Too bad if something else tries to use this pin as digital input.
// See ATmega164/324/644/1284 data sheet, section 18.3.2, page 162.
// Not written there: this must apparently be done before setting the SPRC
// register, else future R/W-operations may hang.
SET_OUTPUT(SS);
#ifdef SPI_2X
SPSR = 0x01;
#else
SPSR = 0x00;
#endif
// This sets the whole SPRC register.
spi_speed_100_400();
}
#endif /* defined TEACUP_C_INCLUDE && defined __AVR__ */

35
spi.c
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@ -1,4 +1,3 @@
/** \file
\brief SPI subsystem
@ -11,36 +10,16 @@
happens before reading and writing, data exchange its self is the same for
each device, then.
*/
#include "spi.h"
#ifdef SPI
/** Initialise SPI subsystem.
Code copied from ATmega164/324/644/1284 data sheet, section 18.2, page 160,
or moved here from mendel.c.
*/
void spi_init() {
// Set SCK (clock) and MOSI line to output, ie. set USART in master mode.
SET_OUTPUT(SCK);
SET_OUTPUT(MOSI);
SET_INPUT(MISO);
// SS must be set as output to disconnect it from the SPI subsystem.
// Too bad if something else tries to use this pin as digital input.
// See ATmega164/324/644/1284 data sheet, section 18.3.2, page 162.
// Not written there: this must apparently be done before setting the SPRC
// register, else future R/W-operations may hang.
SET_OUTPUT(SS);
#ifdef SPI_2X
SPSR = 0x01;
#else
SPSR = 0x00;
#endif
// This sets the whole SPRC register.
spi_speed_100_400();
}
#define TEACUP_C_INCLUDE
#include "spi-avr.c"
// Each ARM needs it's own file
// #include "spi-lpc.c"
// #include "spi-stm32.c"
#undef TEACUP_C_INCLUDE
#endif /* SPI */