+/*****************************************
+ * sllin message helper routines
+ *****************************************/
+
+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;
+}
+
+
+int sllin_send_tx_buff(struct sllin *sl)
+{
+ struct tty_struct *tty = sl->tty;
+ int remains;
+ int res;
+
+ if (sl->lin_state != SLSTATE_BREAK_SENT)
+ remains = sl->tx_lim - sl->tx_cnt;
+ else
+ remains = 1;
+
+
+ res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains);
+ if (res < 0)
+ return -1;
+
+ remains -= res;
+ sl->tx_cnt += res;
+
+ if (remains > 0) {
+ set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+ res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains);
+ if (res < 0) {
+ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+ return -1;
+ }
+
+ remains -= res;
+ sl->tx_cnt += res;
+ }
+
+ printk(KERN_INFO "sllin_send_tx_buff sent %d, remains %d\n",
+ sl->tx_cnt, remains);
+
+ return 0;
+}
+
+int sllin_send_break(struct sllin *sl)
+{
+ struct tty_struct *tty = sl->tty;
+ unsigned long break_baud = sl->lin_baud;
+ int res;
+
+ //break_baud = (break_baud * 8) / 14;
+ break_baud /= 2;
+
+ sltty_change_speed(tty, break_baud);
+
+ sl->rx_expect = SLLIN_BUFF_BREAK + 1;
+
+ sl->lin_state = SLSTATE_BREAK_SENT;
+
+ res = sllin_send_tx_buff(sl);
+ if (res < 0) {
+ sl->lin_state = SLSTATE_IDLE;
+ return res;
+ }
+
+ return 0;
+}
+
+/*****************************************
+ * sllin_kwthread - kernel worker thread
+ *****************************************/
+
+int sllin_kwthread(void *ptr)
+{
+ struct sllin *sl = (struct sllin *)ptr;
+ struct tty_struct *tty = sl->tty;
+ int res;
+
+ printk(KERN_INFO "sllin: sllin_kwthread started.\n");
+
+ clear_bit(SLF_ERROR, &sl->flags);
+
+ sltty_change_speed(tty, sl->lin_baud);
+
+ sllin_setup_msg(sl, 0, 0x33, NULL, 0);
+ sl->id_to_send = 1;
+
+ while (!kthread_should_stop()) {
+
+ if ((sl->lin_state == SLSTATE_IDLE) && sl->lin_master &&
+ sl->id_to_send) {
+ if(sllin_send_break(sl)<0) {
+ /* error processing */
+ }
+
+ }
+
+ wait_event_killable(sl->kwt_wq, kthread_should_stop() ||
+ test_bit(SLF_RXEVENT, &sl->flags) ||
+ test_bit(SLF_TXEVENT, &sl->flags));
+
+ if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) {
+ printk(KERN_INFO "sllin_kthread RXEVENT \n");
+ }
+
+ if (test_and_clear_bit(SLF_TXEVENT, &sl->flags)) {
+ printk(KERN_INFO "sllin_kthread TXEVENT \n");
+ }
+
+ switch (sl->lin_state) {
+ case SLSTATE_BREAK_SENT:
+ if (sl->rx_cnt <= SLLIN_BUFF_BREAK)
+ continue;
+
+ res = sltty_change_speed(tty, sl->lin_baud);
+
+ sllin_send_tx_buff(sl);
+
+ sl->lin_state = SLSTATE_ID_SENT;
+
+ break;
+ case SLSTATE_ID_SENT:
+ sl->id_to_send = 0;
+ sl->lin_state = SLSTATE_IDLE;
+ break;
+ }
+
+
+
+ /* sll_bump(sl); send packet to the network layer */
+
+ /* sl->dev->stats.tx_packets++; send frames statistic */
+ /* netif_wake_queue(sl->dev); allow next Tx packet arrival */
+ }
+
+
+ printk(KERN_INFO "sllin: sllin_kwthread stopped.\n");
+
+ return 0;
+}
+
+