sllin: LIN frame is sent (to TTY) after receiving CAN frame (from network subsystem).

RTR CAN frame received     -> LIN header sent
NON-RTR CAN frame received -> LIN header + LIN response sent

diff --git a/sllin/sllin.c b/sllin/sllin.c
index bd6f3cd6c2ae7fe185257dae122d2f30707e4941..636e89ac848aadbca4ecc4fbed6e3f6e94ae4262 100644 (file)
--- a/sllin/sllin.c
+++ b/sllin/sllin.c
@@ -127,6 +127,8 @@ struct sllin {
        dev_t                   line;
        struct task_struct      *kwthread;
        wait_queue_head_t       kwt_wq;
+
+       struct sk_buff          *rec_skb;       /* Socket buffer with received CAN frame */
 };
 
 static struct net_device **sllin_devs;
@@ -296,8 +298,8 @@ static void sllin_write_wakeup(struct tty_struct *tty)
        struct sllin *sl = (struct sllin *) tty->disc_data;
 
        /* First make sure we're connected. */
-       //if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
-       //      return;
+       if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
+               return;
 
        if (sl->lin_state != SLSTATE_BREAK_SENT)
                remains = sl->tx_lim - sl->tx_cnt;
@@ -328,24 +330,28 @@ static netdev_tx_t sll_xmit(struct sk_buff *skb, struct net_device *dev)
        struct sllin *sl = netdev_priv(dev);
 
        if (skb->len != sizeof(struct can_frame))
-               goto out;
+               goto err_out;
 
        spin_lock(&sl->lock);
        if (!netif_running(dev))  {
                spin_unlock(&sl->lock);
                printk(KERN_WARNING "%s: xmit: iface is down\n", dev->name);
-               goto out;
+               goto err_out;
        }
        if (sl->tty == NULL) {
                spin_unlock(&sl->lock);
-               goto out;
+               goto err_out;
        }
 
        netif_stop_queue(sl->dev);
-       sll_encaps(sl, (struct can_frame *) skb->data); /* encaps & send */
+
+       sl->rec_skb = skb;
+       set_bit(SLF_MSGEVENT, &sl->flags);
+       wake_up(&sl->kwt_wq);
        spin_unlock(&sl->lock);
+       return NETDEV_TX_OK;
 
-out:
+err_out:
        kfree_skb(skb);
        return NETDEV_TX_OK;
 }
@@ -439,8 +445,8 @@ static void sllin_receive_buf(struct tty_struct *tty,
 
        printk(KERN_INFO "sllin_receive_buf invoked\n");
 
-       //if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
-       //      return;
+       if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
+               return;
 
        /* Read the characters out of the buffer */
        while (count--) {
@@ -608,6 +614,8 @@ int sllin_send_break(struct sllin *sl)
        tty->ops->flush_buffer(tty);
 
        sl->tx_cnt = SLLIN_BUFF_SYNC;
+
+       printk(KERN_INFO "sllin: Break sent.\n");
        set_bit(SLF_RXEVENT, &sl->flags);
        wake_up(&sl->kwt_wq);
 
@@ -625,7 +633,7 @@ int sllin_kwthread(void *ptr)
        struct tty_struct *tty = sl->tty;
        struct sched_param schparam = { .sched_priority = 40 };
        int res;
-       unsigned char buff[8] = {0x2, 0x3, 0x4, 0x5};
+       struct can_frame *cf;
 
        printk(KERN_INFO "sllin: sllin_kwthread started.\n");
        sched_setscheduler(current, SCHED_FIFO, &schparam);
@@ -633,10 +641,6 @@ int sllin_kwthread(void *ptr)
        clear_bit(SLF_ERROR, &sl->flags);
        sltty_change_speed(tty, sl->lin_baud);
 
-       //sllin_setup_msg(sl, 0, 0x01, NULL, 0);
-       sllin_setup_msg(sl, 0, 0x02, buff, 4);
-       sl->id_to_send = true;
-
        while (!kthread_should_stop()) {
                if ((sl->lin_state == SLSTATE_IDLE) && sl->lin_master &&
                        sl->id_to_send) {
@@ -647,7 +651,8 @@ int sllin_kwthread(void *ptr)
 
                wait_event_killable(sl->kwt_wq, kthread_should_stop() ||
                        test_bit(SLF_RXEVENT, &sl->flags) ||
-                       test_bit(SLF_TXEVENT, &sl->flags));
+                       test_bit(SLF_TXEVENT, &sl->flags) ||
+                       ((sl->lin_state == SLSTATE_IDLE) && test_bit(SLF_MSGEVENT, &sl->flags)));
 
                if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) {
                        printk(KERN_INFO "sllin_kthread RXEVENT \n");
@@ -657,11 +662,42 @@ int sllin_kwthread(void *ptr)
                        printk(KERN_INFO "sllin_kthread TXEVENT \n");
                }
 
+               if ((sl->lin_state == SLSTATE_IDLE) && test_bit(SLF_MSGEVENT, &sl->flags)) {
+                       cf = (struct can_frame *)sl->rec_skb->data;
+
+                       /* We do care only about SFF frames */
+                       if (cf->can_id & CAN_EFF_FLAG)
+                               goto release_skb;
+
+                       if (cf->can_id & CAN_RTR_FLAG) {
+                               printk(KERN_INFO "%s: RTR CAN frame, ID = %x\n",
+                                       __FUNCTION__, cf->can_id & CAN_SFF_MASK);
+                               if (sllin_setup_msg(sl, 0, 
+                                       cf->can_id & CAN_SFF_MASK, NULL, 0) != -1) {
+                                       sl->id_to_send = true;
+                               }
+                       } else {
+                               printk(KERN_INFO "%s: NON-RTR CAN frame, ID = %x\n",
+                                       __FUNCTION__, (int)cf->can_id & CAN_SFF_MASK);
+
+                               if (sllin_setup_msg(sl, 0, cf->can_id & CAN_SFF_MASK, 
+                                       cf->data, cf->can_dlc) != -1) {
+                                       sl->id_to_send = true;
+                               }
+                       }
+
+               release_skb:
+                       clear_bit(SLF_MSGEVENT, &sl->flags);
+                       kfree_skb(sl->rec_skb);
+                       netif_wake_queue(sl->dev);
+               }
+
                switch (sl->lin_state) {
                        case SLSTATE_BREAK_SENT:
+#ifdef BREAK_BY_BAUD
                                if (sl->rx_cnt <= SLLIN_BUFF_BREAK)
                                        continue;
-#ifdef BREAK_BY_BAUD
+
                                res = sltty_change_speed(tty, sl->lin_baud);
 #endif