X-Git-Url: http://rtime.felk.cvut.cz/gitweb/socketcan-devel.git/blobdiff_plain/cdab1762e9579c00c17880d68f450c4462ff3800..c214d1a46a37635c06c68756baa383b3ac5996ca:/kernel/2.6/include/socketcan/can/gw.h

diff --git a/kernel/2.6/include/socketcan/can/gw.h b/kernel/2.6/include/socketcan/can/gw.h
index 2cf3fb7..e1dfac0 100644
--- a/kernel/2.6/include/socketcan/can/gw.h
+++ b/kernel/2.6/include/socketcan/can/gw.h
@@ -1,12 +1,12 @@
 /*
  * socketcan/can/gw.h
  *
- * Definitions for CAN frame Gateway/Router/Bridge 
+ * Definitions for CAN frame Gateway/Router/Bridge
  *
  * $Id$
  *
  * Author: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
- * Copyright (c) 2002-2010 Volkswagen Group Electronic Research
+ * Copyright (c) 2011 Volkswagen Group Electronic Research
  * All rights reserved.
  *
  * Send feedback to <socketcan-users@lists.berlios.de>
@@ -16,6 +16,7 @@
 #ifndef CAN_GW_H
 #define CAN_GW_H
 
+#include <linux/types.h>
 #include <socketcan/can.h>
 
 struct rtcanmsg {
@@ -78,7 +79,7 @@ struct cgw_csum_xor {
 	__s8 to_idx;
 	__s8 result_idx;
 	__u8 init_xor_val;
-} __attribute__ ((packed));
+} __attribute__((packed));
 
 struct cgw_csum_crc8 {
 	__s8 from_idx;
@@ -87,12 +88,25 @@ struct cgw_csum_crc8 {
 	__u8 init_crc_val;
 	__u8 final_xor_val;
 	__u8 crctab[256];
-} __attribute__ ((packed));
+	__u8 profile;
+	__u8 profile_data[20];
+} __attribute__((packed));
 
 /* length of checksum operation parameters. idx = index in CAN frame data[] */
 #define CGW_CS_XOR_LEN  sizeof(struct cgw_csum_xor)
 #define CGW_CS_CRC8_LEN  sizeof(struct cgw_csum_crc8)
 
+/* CRC8 profiles (compute CRC for additional data elements - see below) */
+enum {
+	CGW_CRC8PRF_UNSPEC,
+	CGW_CRC8PRF_1U8,	/* compute one additional u8 value */
+	CGW_CRC8PRF_16U8,	/* u8 value table indexed by data[1] & 0xF */
+	CGW_CRC8PRF_SFFID_XOR,	/* (can_id & 0xFF) ^ (can_id >> 8 & 0xFF) */
+	__CGW_CRC8PRF_MAX
+};
+
+#define CGW_CRC8PRF_MAX (__CGW_CRC8PRF_MAX - 1)
+
 /*
  * CAN rtnetlink attribute contents in detail
  *
@@ -118,13 +132,13 @@ struct cgw_csum_crc8 {
  * The XOR checksum is calculated like this:
  *
  * xor = init_xor_val
- * 
+ *
  * for (i = from_idx .. to_idx)
  *      xor ^= can_frame.data[i]
  *
  * can_frame.data[ result_idx ] = xor
  *
- * CGW_CS_CRC8 (length 261 bytes):
+ * CGW_CS_CRC8 (length 282 bytes):
  * Set a CRC8 value into data[result-idx] using a given 256 byte CRC8 table,
  * a given initial value and a defined input data[start-idx] .. data[end-idx].
  * Finally the result value is XOR'ed with the final_xor_val.
@@ -132,12 +146,19 @@ struct cgw_csum_crc8 {
  * The CRC8 checksum is calculated like this:
  *
  * crc = init_crc_val
- * 
+ *
  * for (i = from_idx .. to_idx)
  *      crc = crctab[ crc ^ can_frame.data[i] ]
  *
  * can_frame.data[ result_idx ] = crc ^ final_xor_val
  *
+ * The calculated CRC may contain additional source data elements that can be
+ * defined in the handling of 'checksum profiles' e.g. shown in AUTOSAR specs
+ * like http://www.autosar.org/download/R4.0/AUTOSAR_SWS_E2ELibrary.pdf
+ * E.g. the profile_data[] may contain additional u8 values (called DATA_IDs)
+ * that are used depending on counter values inside the CAN frame data[].
+ * So far only three profiles have been implemented for illustration.
+ *
  * Remark: In general the attribute data is a linear buffer.
  *         Beware of sending unpacked or aligned structs!
  */