1 files changed, 123 insertions, 0 deletions
diff --git a/firmware/fx2/common/i2c.c b/firmware/fx2/common/i2c.c
new file mode 100644
index 000000000..0f238b5cf
--- /dev/null
+++ b/firmware/fx2/common/i2c.c
@@ -0,0 +1,123 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2003 Free Software Foundation, Inc.
+ * 
+ * This file is part of GNU Radio
+ * 
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ * 
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "i2c.h"
+#include "fx2regs.h"
+#include <string.h>
+
+
+// issue a stop bus cycle and wait for completion
+
+
+// returns non-zero if successful, else 0
+unsigned char
+i2c_read (unsigned char addr, xdata unsigned char *buf, unsigned char len)
+{
+  volatile unsigned char	junk;
+  
+  if (len == 0)			// reading zero bytes always works
+    return 1;
+  
+  while (I2CS & bmSTOP)		// wait for stop to clear
+    ;
+
+  I2CS = bmSTART;
+  I2DAT = (addr << 1) | 1;	// write address and direction (1's the read bit)
+
+  while ((I2CS & bmDONE) == 0)
+    ;
+
+  if ((I2CS & bmBERR) || (I2CS & bmACK) == 0)	// no device answered...
+    goto fail;
+
+  if (len == 1)
+    I2CS |= bmLASTRD;		
+
+  junk = I2DAT;			// trigger the first read cycle
+
+  while (--len != 0){
+    while ((I2CS & bmDONE) == 0)
+      ;
+
+    if (I2CS & bmBERR)
+      goto fail;
+
+    if (len == 1)
+      I2CS |= bmLASTRD;
+    
+    *buf++ = I2DAT;		// get data, trigger another read
+  }
+
+  // wait for final byte
+  
+  while ((I2CS & bmDONE) == 0)
+    ;
+  
+  if (I2CS & bmBERR)
+    goto fail;
+
+  I2CS |= bmSTOP;
+  *buf = I2DAT;
+
+  return 1;
+
+ fail:
+  I2CS |= bmSTOP;
+  return 0;
+}
+
+
+
+// returns non-zero if successful, else 0
+unsigned char
+i2c_write (unsigned char addr, xdata const unsigned char *buf, unsigned char len)
+{
+  while (I2CS & bmSTOP)		// wait for stop to clear
+    ;
+
+  I2CS = bmSTART;
+  I2DAT = (addr << 1) | 0;	// write address and direction (0's the write bit)
+
+  while ((I2CS & bmDONE) == 0)
+    ;
+
+  if ((I2CS & bmBERR) || (I2CS & bmACK) == 0)	// no device answered...
+    goto fail;
+
+  while (len > 0){
+    I2DAT = *buf++;
+    len--;
+
+    while ((I2CS & bmDONE) == 0)
+      ;
+
+    if ((I2CS & bmBERR) || (I2CS & bmACK) == 0)	// no device answered...
+      goto fail;
+  }
+
+  I2CS |= bmSTOP;
+  return 1;
+
+ fail:
+  I2CS |= bmSTOP;
+  return 0;
+}