Support CAN XL payload length and DLC definitions according to ISO 11898-1.

Author: Apaisal

examples/csp_server.c

@@ -13,25 +13,71 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
-#include <linux/can.h>
 #include <linux/can/raw.h>
 
 #include <csp/csp.h>
 #include <csp/drivers/usart.h>
 #include <csp/drivers/can_socketcan.h>
 #include <csp/interfaces/csp_if_zmqhub.h>
 
+#ifndef CANXL_XLF
+/*
+ * CAN XL payload length and DLC definitions according to ISO 11898-1
+ * CAN XL DLC ranges from 0 .. 2047 => data length from 1 .. 2048 byte
+ */
+#define CANXL_MIN_DLC 0
+#define CANXL_MAX_DLC 2047
+#define CANXL_MAX_DLC_MASK 0x07FF
+#define CANXL_MIN_DLEN 1
+#define CANXL_MAX_DLEN 2048
+
 /* valid bits in CAN ID for frame formats */
 #define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
 #define CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */
 #define CAN_ERR_MASK 0x1FFFFFFFU /* omit EFF, RTR, ERR flags */
 #define CANXL_PRIO_MASK CAN_SFF_MASK /* 11 bit priority mask */
 
+/*
+ * defined bits for canxl_frame.flags
+ *
+ * The canxl_frame.flags element contains two bits CANXL_XLF and CANXL_SEC
+ * and shares the relative position of the struct can[fd]_frame.len element.
+ * The CANXL_XLF bit ALWAYS needs to be set to indicate a valid CAN XL frame.
+ * As a side effect setting this bit intentionally breaks the length checks
+ * for Classical CAN and CAN FD frames.
+ *
+ * Undefined bits in canxl_frame.flags are reserved and shall be set to zero.
+ */
+#define CANXL_XLF 0x80 /* mandatory CAN XL frame flag (must always be set!) */
+#define CANXL_SEC 0x01 /* Simple Extended Content (security/segmentation) */
+
 /* the 8-bit VCID is optionally placed in the canxl_frame.prio element */
 #define CANXL_VCID_OFFSET 16 /* bit offset of VCID in prio element */
 #define CANXL_VCID_VAL_MASK 0xFFUL /* VCID is an 8-bit value */
 #define CANXL_VCID_MASK (CANXL_VCID_VAL_MASK << CANXL_VCID_OFFSET)
 
+/**
+ * struct canxl_frame - CAN with e'X'tended frame 'L'ength frame structure
+ * @prio:  11 bit arbitration priority with zero'ed CAN_*_FLAG flags / VCID
+ * @flags: additional flags for CAN XL
+ * @sdt:   SDU (service data unit) type
+ * @len:   frame payload length in byte (CANXL_MIN_DLEN .. CANXL_MAX_DLEN)
+ * @af:    acceptance field
+ * @data:  CAN XL frame payload (CANXL_MIN_DLEN .. CANXL_MAX_DLEN byte)
+ *
+ * @prio shares the same position as @can_id from struct can[fd]_frame.
+ */
+
+struct canxl_frame {
+	canid_t prio;  /* 11 bit priority for arbitration / 8 bit VCID */
+	__u8    flags; /* additional flags for CAN XL */
+	__u8    sdt;   /* SDU (service data unit) type */
+	__u16   len;   /* frame payload length in byte */
+	__u32   af;    /* acceptance field */
+	__u8    data[CANXL_MAX_DLEN];
+};
+#endif
+
 /* CAN CC/FD/XL frame union */
 typedef union {
 	struct can_frame cc;