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authorJosh Blum <josh@joshknows.com>2010-11-05 12:32:09 -0700
committerJosh Blum <josh@joshknows.com>2010-11-05 12:32:09 -0700
commitc473cc56fafcb47d6ba1f16e8c9fb89ff6c57bca (patch)
tree4760fc8fd3f409831dda97b81b65b379abfd61fc /firmware/fx2/common/i2c.c
parent7a7e704fa3d79036da1f33013e761eb747b725f0 (diff)
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usrp1: pulled in cmake build system for usrp1 firmware
Diffstat (limited to 'firmware/fx2/common/i2c.c')
-rw-r--r--firmware/fx2/common/i2c.c123
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;
+}