diff --git a/wiringPi/wiringPiSPI.c b/wiringPi/wiringPiSPI.c index 215a027..020822f 100644 --- a/wiringPi/wiringPiSPI.c +++ b/wiringPi/wiringPiSPI.c @@ -1,7 +1,7 @@ /* * wiringPiSPI.c: * Simplified SPI access routines - * Copyright (c) 2012 Gordon Henderson + * Copyright (c) 2012-2015 Gordon Henderson *********************************************************************** * This file is part of wiringPi: * https://projects.drogon.net/raspberry-pi/wiringpi/ @@ -28,6 +28,7 @@ #include #include #include +#include #include #include "wiringPi.h" @@ -38,11 +39,10 @@ // The SPI bus parameters // Variables as they need to be passed as pointers later on -const static char *spiDev0 = "/dev/spidev0.0" ; -const static char *spiDev1 = "/dev/spidev0.1" ; -const static uint8_t spiMode = 0 ; -const static uint8_t spiBPW = 8 ; -const static uint16_t spiDelay = 0 ; +static const char *spiDev0 = "/dev/spidev0.0" ; +static const char *spiDev1 = "/dev/spidev0.1" ; +static const uint8_t spiBPW = 8 ; +static const uint16_t spiDelay = 0 ; static uint32_t spiSpeeds [2] ; static int spiFds [2] ; @@ -75,6 +75,11 @@ int wiringPiSPIDataRW (int channel, unsigned char *data, int len) channel &= 1 ; +// Mentioned in spidev.h but not used in the original kernel documentation +// test program )-: + + memset (&spi, 0, sizeof (spi)) ; + spi.tx_buf = (unsigned long)data ; spi.rx_buf = (unsigned long)data ; spi.len = len ; @@ -87,16 +92,17 @@ int wiringPiSPIDataRW (int channel, unsigned char *data, int len) /* - * wiringPiSPISetup: - * Open the SPI device, and set it up, etc. + * wiringPiSPISetupMode: + * Open the SPI device, and set it up, with the mode, etc. ********************************************************************************* */ -int wiringPiSPISetup (int channel, int speed) +int wiringPiSPISetupMode (int channel, int speed, int mode) { int fd ; - channel &= 1 ; + mode &= 3 ; // Mode is 0, 1, 2 or 3 + channel &= 1 ; // Channel is 0 or 1 if ((fd = open (channel == 0 ? spiDev0 : spiDev1, O_RDWR)) < 0) return wiringPiFailure (WPI_ALMOST, "Unable to open SPI device: %s\n", strerror (errno)) ; @@ -105,12 +111,10 @@ int wiringPiSPISetup (int channel, int speed) spiFds [channel] = fd ; // Set SPI parameters. -// Why are we reading it afterwriting it? I've no idea, but for now I'm blindly -// copying example code I've seen online... - if (ioctl (fd, SPI_IOC_WR_MODE, &spiMode) < 0) + if (ioctl (fd, SPI_IOC_WR_MODE, &mode) < 0) return wiringPiFailure (WPI_ALMOST, "SPI Mode Change failure: %s\n", strerror (errno)) ; - + if (ioctl (fd, SPI_IOC_WR_BITS_PER_WORD, &spiBPW) < 0) return wiringPiFailure (WPI_ALMOST, "SPI BPW Change failure: %s\n", strerror (errno)) ; @@ -119,3 +123,15 @@ int wiringPiSPISetup (int channel, int speed) return fd ; } + + +/* + * wiringPiSPISetup: + * Open the SPI device, and set it up, etc. in the default MODE 0 + ********************************************************************************* + */ + +int wiringPiSPISetup (int channel, int speed) +{ + return wiringPiSPISetupMode (channel, speed, 0) ; +} diff --git a/wiringPi/wiringPiSPI.h b/wiringPi/wiringPiSPI.h index f53697d..48cb7be 100644 --- a/wiringPi/wiringPiSPI.h +++ b/wiringPi/wiringPiSPI.h @@ -28,6 +28,7 @@ extern "C" { int wiringPiSPIGetFd (int channel) ; int wiringPiSPIDataRW (int channel, unsigned char *data, int len) ; +int wiringPiSPISetupMode (int channel, int speed, int mode) ; int wiringPiSPISetup (int channel, int speed) ; #ifdef __cplusplus