Added missing inclusion of linux/types.h

[socketcan-devel.git] / 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 f8ead84eab8e93edd530951d430a95087a1e7181..e1dfac0579b2bf2c3be30cb01d321e69ca17ac3e 100644 (file)
--- 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 {
@@ -77,20 +78,35 @@ struct cgw_csum_xor {
        __s8 from_idx;
        __s8 to_idx;
        __s8 result_idx;
-       __u8 prefix_value;
-} __attribute__ ((packed));
+       __u8 init_xor_val;
+} __attribute__((packed));
 
 struct cgw_csum_crc8 {
        __s8 from_idx;
        __s8 to_idx;
        __s8 result_idx;
+       __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
  *
@@ -110,14 +126,41 @@ struct cgw_csum_crc8 {
  * <u8> affected CAN frame elements
  *
  * CGW_CS_XOR (length 4 bytes):
- * Set a simple XOR checksum starting with the initial prefix-value into
+ * Set a simple XOR checksum starting with an initial value into
  * data[result-idx] using data[start-idx] .. data[end-idx]
  *
- * CGW_CS_CRC8 (length 259 bytes):
- * Set a CRC8 value into data[result-idx] using a given 256 byte CRC8 table and
- * a defined input data[start-idx] .. data[end-idx]
+ * 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 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.
+ *
+ * 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: The attribute data is a linear buffer. Beware of sending structs!
+ * Remark: In general the attribute data is a linear buffer.
+ *         Beware of sending unpacked or aligned structs!
  */
 
 #endif