Updates to the build process

[wiringPi.git] / wiringPi / wiringPiSPI.c

diff --git a/wiringPi/wiringPiSPI.c b/wiringPi/wiringPiSPI.c
index f2e30003ed1c28306b1c204f996f1d82c88a469d..453df31d434e2054c7ebc85a73a6a4d111c84671 100644 (file)
--- 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/
@@ -25,20 +25,23 @@
 
 #include <stdint.h>
 #include <fcntl.h>
+#include <errno.h>
+#include <string.h>
 #include <sys/ioctl.h>
 #include <linux/spi/spidev.h>
 
+#include "wiringPi.h"
+
 #include "wiringPiSPI.h"
 
 
 // The SPI bus parameters
 //     Variables as they need to be passed as pointers later on
 
-static char       *spiDev0 = "/dev/spidev0.0" ;
-static char       *spiDev1 = "/dev/spidev0.1" ;
-static uint8_t     spiMode   = 0 ;
-static uint8_t     spiBPW    = 8 ;
-static uint16_t    spiDelay  = 0;
+const static char       *spiDev0  = "/dev/spidev0.0" ;
+const static char       *spiDev1  = "/dev/spidev0.1" ;
+const static uint8_t     spiBPW   = 8 ;
+const static uint16_t    spiDelay = 0 ;
 
 static uint32_t    spiSpeeds [2] ;
 static int         spiFds [2] ;
@@ -52,7 +55,7 @@ static int         spiFds [2] ;
 
 int wiringPiSPIGetFd (int channel)
 {
-  return spiFds [channel &1] ;
+  return spiFds [channel & 1] ;
 }
 
 
@@ -71,6 +74,11 @@ 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 ;
@@ -83,35 +91,46 @@ 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 -1 ;
+    return wiringPiFailure (WPI_ALMOST, "Unable to open SPI device: %s\n", strerror (errno)) ;
 
   spiSpeeds [channel] = 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) return -1 ;
-  if (ioctl (fd, SPI_IOC_RD_MODE, &spiMode)         < 0) return -1 ;
 
-  if (ioctl (fd, SPI_IOC_WR_BITS_PER_WORD, &spiBPW) < 0) return -1 ;
-  if (ioctl (fd, SPI_IOC_RD_BITS_PER_WORD, &spiBPW) < 0) return -1 ;
+  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)) ;
 
-  if (ioctl (fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed)   < 0) return -1 ;
-  if (ioctl (fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed)   < 0) return -1 ;
+  if (ioctl (fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed)   < 0)
+    return wiringPiFailure (WPI_ALMOST, "SPI Speed Change failure: %s\n", strerror (errno)) ;
 
   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) ;
+}