Userspace LIN master: Provide state encapsulation to test kernel code.

[linux-lin.git] / misc / tty_lin_master / lin_common.c

diff --git a/misc/tty_lin_master/lin_common.c b/misc/tty_lin_master/lin_common.c
new file mode 100644 (file)
index 0000000..6fffafc
--- /dev/null
+++ b/misc/tty_lin_master/lin_common.c
@@ -0,0 +1,51 @@
+#include <string.h>
+#include "lin_common.h"
+
+const unsigned char sllin_id_parity_table[64] = {
+        0x80,0xc0,0x40,0x00,0xc0,0x80,0x00,0x40,
+        0x00,0x40,0xc0,0x80,0x40,0x00,0x80,0xc0,
+        0x40,0x00,0x80,0xc0,0x00,0x40,0xc0,0x80,
+        0xc0,0x80,0x00,0x40,0x80,0xc0,0x40,0x00,
+        0x00,0x40,0xc0,0x80,0x40,0x00,0x80,0xc0,
+        0x80,0xc0,0x40,0x00,0xc0,0x80,0x00,0x40,
+        0xc0,0x80,0x00,0x40,0x80,0xc0,0x40,0x00,
+        0x40,0x00,0x80,0xc0,0x00,0x40,0xc0,0x80
+};
+
+
+int sllin_setup_msg(struct sllin *sl, int mode, int id,
+               unsigned char *data, int len)
+{
+       if (id > 0x3f)
+               return -1;
+
+       sl->rx_cnt = 0;
+       sl->tx_cnt = 0;
+       sl->rx_expect = 0;
+
+       sl->tx_buff[SLLIN_BUFF_BREAK] = 0;
+       sl->tx_buff[SLLIN_BUFF_SYNC]  = 0x55;
+       sl->tx_buff[SLLIN_BUFF_ID]    = id | sllin_id_parity_table[id];
+       sl->tx_lim = SLLIN_BUFF_DATA;
+
+       if ((data != NULL) && len) {
+               int i;
+               unsigned csum  = 0;
+
+               sl->tx_lim += len;
+               memcpy(sl->tx_buff + SLLIN_BUFF_DATA, data, len);
+               /* compute data parity there */
+               for (i = SLLIN_BUFF_DATA; i < sl->tx_lim; i++) {
+                       csum += sl->tx_buff[i];
+                       if (csum > 255)
+                               csum -= 255;
+               }
+
+               sl->tx_buff[sl->tx_lim++] = csum;
+       }
+       if (len != 0)
+               sl->rx_lim += len + 1;
+
+       return 0;
+}
+