Add CRC16 support

5 files changed, 229 insertions, 6 deletions

diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index d822b36a5..470f72fe6 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -5113,4 +5113,6 @@
 	  (2013-7-4).
 	* arch/arm/src/sam34/sam3u_gpio.c:  sam_configgpio() must protect
 	  against re-entrancy (2013-7-5).
+	* libc/misc/lib_crc16.c and include/crc16.h:  Add CRC16 support
+	  (2013-7-7).
 
diff --git a/nuttx/include/crc16.h b/nuttx/include/crc16.h
new file mode 100644
index 000000000..eee38567a
--- /dev/null
+++ b/nuttx/include/crc16.h
@@ -0,0 +1,83 @@
+/****************************************************************************
+ * include/crc16.h
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_CRC16_H
+#define __INCLUDE_CRC16_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <sys/types.h>
+#include <stdint.h>
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: crc16part
+ *
+ * Description:
+ *   Continue CRC calculation on a part of the buffer.
+ *
+ ****************************************************************************/
+
+uint16_t crc16part(FAR const uint8_t *src, size_t len, uint16_t crc16val);
+
+/****************************************************************************
+ * Name: crc16
+ *
+ * Description:
+ *   Return a 16-bit CRC of the contents of the 'src' buffer, length 'len'
+ *
+ ****************************************************************************/
+
+uint16_t crc16(FAR const uint8_t *src, size_t len);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __INCLUDE_CRC16_H */
diff --git a/nuttx/include/crc32.h b/nuttx/include/crc32.h
index 1dd6fff13..1a6c97da0 100644
--- a/nuttx/include/crc32.h
+++ b/nuttx/include/crc32.h
@@ -1,5 +1,5 @@
 /****************************************************************************
- * include/crc.h
+ * include/crc32.h
  *
  *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
@@ -49,7 +49,8 @@
 
 #ifdef __cplusplus
 #define EXTERN extern "C"
-extern "C" {
+extern "C"
+{
 #else
 #define EXTERN extern
 #endif
@@ -62,8 +63,7 @@ extern "C" {
  *
  ****************************************************************************/
 
-EXTERN uint32_t crc32part(FAR const uint8_t *src, size_t len,
-                          uint32_t crc32val);
+uint32_t crc32part(FAR const uint8_t *src, size_t len, uint32_t crc32val);
 
 /****************************************************************************
  * Name: crc32
@@ -73,7 +73,7 @@ EXTERN uint32_t crc32part(FAR const uint8_t *src, size_t len,
  *
  ****************************************************************************/
 
-EXTERN uint32_t crc32(FAR const uint8_t *src, size_t len);
+uint32_t crc32(FAR const uint8_t *src, size_t len);
 
 #undef EXTERN
 #ifdef __cplusplus
diff --git a/nuttx/libc/misc/Make.defs b/nuttx/libc/misc/Make.defs
index 02b3b2679..20b1dc1d0 100644
--- a/nuttx/libc/misc/Make.defs
+++ b/nuttx/libc/misc/Make.defs
@@ -60,7 +60,7 @@ endif
 # Add the miscellaneous C files to the build
 
 CSRCS += lib_match.c
-CSRCS += lib_crc32.c
+CSRCS += lib_crc32.c lib_crc16.c
 CSRCS += lib_dbg.c lib_dumpbuffer.c
 
 # Keyboard driver encoder/decoder
diff --git a/nuttx/libc/misc/lib_crc16.c b/nuttx/libc/misc/lib_crc16.c
new file mode 100644
index 000000000..065c586ee
--- /dev/null
+++ b/nuttx/libc/misc/lib_crc16.c
@@ -0,0 +1,138 @@
+/************************************************************************************************
+ * libc/misc/lib_crc16.c
+ *
+ * This file is a part of NuttX:
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * References:
+ *
+ *   crc16_tab calculated by Mark G. Mendel, Network Systems Corporation.
+ *   crc16part() logic derived from article Copyright (C) 1986 Stephen Satchell.
+ *
+ * "Programmers may incorporate any or all code into their programs,
+ *  giving proper credit within the source. Publication of the
+ *  source routines is permitted so long as proper credit is given
+ *  to Stephen Satchell, Satchell Evaluations and Chuck Forsberg,
+ *  Omen Technology."
+ *
+ * Re-released under the Modified BSD license which, I believe, is consistent with the
+ * original authors' intent:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************************************************/
+
+/************************************************************************************************
+ * Included Files
+ ************************************************************************************************/
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <crc16.h>
+
+/************************************************************************************************
+ * Private Data
+ ************************************************************************************************/
+
+/* crc16_tab calculated by Mark G. Mendel, Network Systems Corporation */
+
+static uint16_t crc16_tab[256] =
+{
+  0x0000,  0x1021,  0x2042,  0x3063,  0x4084,  0x50a5,  0x60c6,  0x70e7,
+  0x8108,  0x9129,  0xa14a,  0xb16b,  0xc18c,  0xd1ad,  0xe1ce,  0xf1ef,
+  0x1231,  0x0210,  0x3273,  0x2252,  0x52b5,  0x4294,  0x72f7,  0x62d6,
+  0x9339,  0x8318,  0xb37b,  0xa35a,  0xd3bd,  0xc39c,  0xf3ff,  0xe3de,
+  0x2462,  0x3443,  0x0420,  0x1401,  0x64e6,  0x74c7,  0x44a4,  0x5485,
+  0xa56a,  0xb54b,  0x8528,  0x9509,  0xe5ee,  0xf5cf,  0xc5ac,  0xd58d,
+  0x3653,  0x2672,  0x1611,  0x0630,  0x76d7,  0x66f6,  0x5695,  0x46b4,
+  0xb75b,  0xa77a,  0x9719,  0x8738,  0xf7df,  0xe7fe,  0xd79d,  0xc7bc,
+  0x48c4,  0x58e5,  0x6886,  0x78a7,  0x0840,  0x1861,  0x2802,  0x3823,
+  0xc9cc,  0xd9ed,  0xe98e,  0xf9af,  0x8948,  0x9969,  0xa90a,  0xb92b,
+  0x5af5,  0x4ad4,  0x7ab7,  0x6a96,  0x1a71,  0x0a50,  0x3a33,  0x2a12,
+  0xdbfd,  0xcbdc,  0xfbbf,  0xeb9e,  0x9b79,  0x8b58,  0xbb3b,  0xab1a,
+  0x6ca6,  0x7c87,  0x4ce4,  0x5cc5,  0x2c22,  0x3c03,  0x0c60,  0x1c41,
+  0xedae,  0xfd8f,  0xcdec,  0xddcd,  0xad2a,  0xbd0b,  0x8d68,  0x9d49,
+  0x7e97,  0x6eb6,  0x5ed5,  0x4ef4,  0x3e13,  0x2e32,  0x1e51,  0x0e70,
+  0xff9f,  0xefbe,  0xdfdd,  0xcffc,  0xbf1b,  0xaf3a,  0x9f59,  0x8f78,
+  0x9188,  0x81a9,  0xb1ca,  0xa1eb,  0xd10c,  0xc12d,  0xf14e,  0xe16f,
+  0x1080,  0x00a1,  0x30c2,  0x20e3,  0x5004,  0x4025,  0x7046,  0x6067,
+  0x83b9,  0x9398,  0xa3fb,  0xb3da,  0xc33d,  0xd31c,  0xe37f,  0xf35e,
+  0x02b1,  0x1290,  0x22f3,  0x32d2,  0x4235,  0x5214,  0x6277,  0x7256,
+  0xb5ea,  0xa5cb,  0x95a8,  0x8589,  0xf56e,  0xe54f,  0xd52c,  0xc50d,
+  0x34e2,  0x24c3,  0x14a0,  0x0481,  0x7466,  0x6447,  0x5424,  0x4405,
+  0xa7db,  0xb7fa,  0x8799,  0x97b8,  0xe75f,  0xf77e,  0xc71d,  0xd73c,
+  0x26d3,  0x36f2,  0x0691,  0x16b0,  0x6657,  0x7676,  0x4615,  0x5634,
+  0xd94c,  0xc96d,  0xf90e,  0xe92f,  0x99c8,  0x89e9,  0xb98a,  0xa9ab,
+  0x5844,  0x4865,  0x7806,  0x6827,  0x18c0,  0x08e1,  0x3882,  0x28a3,
+  0xcb7d,  0xdb5c,  0xeb3f,  0xfb1e,  0x8bf9,  0x9bd8,  0xabbb,  0xbb9a,
+  0x4a75,  0x5a54,  0x6a37,  0x7a16,  0x0af1,  0x1ad0,  0x2ab3,  0x3a92,
+  0xfd2e,  0xed0f,  0xdd6c,  0xcd4d,  0xbdaa,  0xad8b,  0x9de8,  0x8dc9,
+  0x7c26,  0x6c07,  0x5c64,  0x4c45,  0x3ca2,  0x2c83,  0x1ce0,  0x0cc1,
+  0xef1f,  0xff3e,  0xcf5d,  0xdf7c,  0xaf9b,  0xbfba,  0x8fd9,  0x9ff8,
+  0x6e17,  0x7e36,  0x4e55,  0x5e74,  0x2e93,  0x3eb2,  0x0ed1,  0x1ef0
+};
+
+#define updcrc(cp, crc) ( crc16_tab[((crc >> 8) & 255)] ^ (crc << 8) ^ cp)
+
+/************************************************************************************************
+ * Public Functions
+ ************************************************************************************************/
+/************************************************************************************************
+ * Name: crc16part
+ *
+ * Description:
+ *   Continue CRC calculation on a part of the buffer.
+ *
+ ************************************************************************************************/
+
+uint16_t crc16part(FAR const uint8_t *src, size_t len, uint16_t crc16val)
+{
+  size_t i;
+
+  for (i = 0;  i < len;  i++)
+    {
+      crc16val = crc16_tab[((crc16val >> 8) & 255)] ^ (crc16val << 8) ^ src[i];
+    }
+
+  return crc16val;
+}
+
+/************************************************************************************************
+ * Name: crc16
+ *
+ * Description:
+ *   Return a 16-bit CRC of the contents of the 'src' buffer, length 'len'
+ *
+ ************************************************************************************************/
+
+uint16_t crc16(FAR const uint8_t *src, size_t len)
+{
+  return crc16part(src, len, 0);
+}