+const char hex_asc_upper[] = "0123456789ABCDEF";
+
+#define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0F)]
+#define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xF0) >> 4]
+
+static inline void put_hex_byte(char *buf, __u8 byte)
+{
+ buf[0] = hex_asc_upper_hi(byte);
+ buf[1] = hex_asc_upper_lo(byte);
+}
+
+static inline void _put_id(char *buf, int end_offset, canid_t id)
+{
+ /* build 3 (SFF) or 8 (EFF) digit CAN identifier */
+ while (end_offset >= 0) {
+ buf[end_offset--] = hex_asc_upper[id & 0xF];
+ id >>= 4;
+ }
+}
+
+#define put_sff_id(buf, id) _put_id(buf, 2, id)
+#define put_eff_id(buf, id) _put_id(buf, 7, id)
+