]> rtime.felk.cvut.cz Git - linux-lin.git/blobdiff - sllin/sllin.c
sllin: Time to sleep during sending Break is computed depending on baud rate.
[linux-lin.git] / sllin / sllin.c
index 011743ec5992d2714c6f1577f0424802487b38bb..51b501d5aa759b25961cb78866464f6874658a1a 100644 (file)
@@ -1,11 +1,8 @@
 /*
  * sllin.c - serial line LIN interface driver (using tty line discipline)
  *
- * This file is derived from linux/drivers/net/slip.c
- *
- * slip.c Authors  : Laurence Culhane <loz@holmes.demon.co.uk>
- *                   Fred N. van Kempen <waltje@uwalt.nl.mugnet.org>
- * sllin.c Author  : Oliver Hartkopp <socketcan@hartkopp.net>
+ * This file is derived from drivers/net/can/slcan.c
+ * slcan.c Author: Oliver Hartkopp <socketcan@hartkopp.net>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -58,6 +55,7 @@
 #include <linux/init.h>
 #include <linux/can.h>
 #include <linux/kthread.h>
+#include <linux/hrtimer.h>
 
 /* Should be in include/linux/tty.h */
 #define N_SLLIN         25
@@ -68,9 +66,10 @@ static __initdata const char banner[] =
 MODULE_ALIAS_LDISC(N_SLLIN);
 MODULE_DESCRIPTION("serial line LIN interface");
 MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
+MODULE_AUTHOR("");
 
 #define SLLIN_MAGIC 0x53CA
+// #define BREAK_BY_BAUD
 
 static int maxdev = 10;                /* MAX number of SLLIN channels;
                                   This can be overridden with
@@ -87,14 +86,41 @@ MODULE_PARM_DESC(maxdev, "Maximum number of sllin interfaces");
 #define SLLIN_BUFF_ID   2
 #define SLLIN_BUFF_DATA         3
 
+#define SLLIN_ID_MASK  0x3f
+#define SLLIN_ID_MAX   SLLIN_ID_MASK
+#define SLLIN_STATUS_FLAG SLLIN_EFF_FLAG
+
 enum slstate {
        SLSTATE_IDLE = 0,
        SLSTATE_BREAK_SENT,
        SLSTATE_ID_SENT,
-       SLSTATE_RESPONSE_WAIT,
+       SLSTATE_RESPONSE_WAIT, /* Wait for response */
+       SLSTATE_RESPONSE_WAIT_BUS, /* Wait for response from LIN bus
+                               only (CAN frames from network stack
+                               are not processed in this moment) */
        SLSTATE_RESPONSE_SENT,
 };
 
+struct sllin_conf_entry {
+       int dlc;                /* Length of data in LIN frame */
+#define SLLIN_CANFR_FLAGS_OFFS 6 /* Lower 6 bits in can_id correspond to LIN ID */
+/* Save configuration for particualr LIN ID */
+#define SLLIN_LIN_ID_CONF      (1 <<  SLLIN_CANFR_FLAGS_OFFS)
+/* Publisher of particular LIN response is SLLIN Master */
+#define SLLIN_SRC_MASTER       (1 << (SLLIN_CANFR_FLAGS_OFFS + 1))
+#define SLLIN_SRC_SLAVE                (1 << (SLLIN_CANFR_FLAGS_OFFS + 2))
+#define SLLIN_SLAVE_LOCAL      (1 << (SLLIN_CANFR_FLAGS_OFFS + 3))
+#define SLLIN_SLAVE_REMOTE     (1 << (SLLIN_CANFR_FLAGS_OFFS + 4))
+#define SLLIN_LOC_SLAVE_CACHE  (1 << (SLLIN_CANFR_FLAGS_OFFS + 5))
+
+#define SLLIN_ERR_RX_TIMEOUT    (1 << (SLLIN_CANFR_FLAGS_OFFS + 6))
+#define SLLIN_ERR_CHECKSUM      (1 << (SLLIN_CANFR_FLAGS_OFFS + 7))
+//#define SLLIN_ERR_FRAMING     (1 << (SLLIN_CANFR_FLAGS_OFFS + 8))
+
+       canid_t frame_fl;       /* LIN frame flags. Passed from userspace as canid_t data type */
+       u8 data[8];             /* LIN frame data payload */
+};
+
 struct sllin {
        int                     magic;
 
@@ -107,14 +133,16 @@ struct sllin {
        unsigned char           rx_buff[SLLIN_BUFF_LEN]; /* LIN Rx buffer */
        unsigned char           tx_buff[SLLIN_BUFF_LEN]; /* LIN Tx buffer */
        int                     rx_expect;      /* expected number of Rx chars */
-       int                     rx_lim;         /* maximum Rx chars for ID  */
+       int                     rx_lim;         /* maximum Rx chars for current frame */
        int                     rx_cnt;         /* message buffer Rx fill level  */
        int                     tx_lim;         /* actual limit of bytes to Tx */
        int                     tx_cnt;         /* number of already Tx bytes */
        char                    lin_master;     /* node is a master node */
        int                     lin_baud;       /* LIN baudrate */
        int                     lin_state;      /* state */
-       int                     id_to_send;     /* there is ID to be sent */
+       char                    id_to_send;     /* there is ID to be sent */
+       char                    data_to_send;   /* there are data to be sent */
+       char                    resp_len_known; /* Length of the response is known */
 
        unsigned long           flags;          /* Flag values/ mode etc     */
 #define SLF_INUSE              0               /* Channel in use            */
@@ -122,11 +150,18 @@ struct sllin {
 #define SLF_RXEVENT            2               /* Rx wake event             */
 #define SLF_TXEVENT            3               /* Tx wake event             */
 #define SLF_MSGEVENT           4               /* CAN message to sent       */
+#define SLF_TMOUTEVENT          5               /* Timeout on received data  */
 
-       unsigned char           leased;
        dev_t                   line;
        struct task_struct      *kwthread;
        wait_queue_head_t       kwt_wq;
+       struct hrtimer          rx_timer;       /* RX timeout timer */
+       ktime_t                 rx_timer_timeout; /* RX timeout timer value */
+       struct sk_buff          *tx_req_skb;    /* Socket buffer with CAN frame received
+                                               from network stack*/
+
+       struct sllin_conf_entry linfr_cache[SLLIN_ID_MAX + 1]; /* List with configurations for
+                                               each of 0 to SLLIN_ID_MAX LIN IDs */
 };
 
 static struct net_device **sllin_devs;
@@ -148,135 +183,59 @@ static int sltty_change_speed(struct tty_struct *tty, unsigned speed)
        int cflag;
 
        mutex_lock(&tty->termios_mutex);
+
        old_termios = *(tty->termios);
        cflag = tty->termios->c_cflag;
+       cflag &= ~(CBAUD | CIBAUD);
+       cflag |= BOTHER;
+       tty->termios->c_cflag = cflag;
+
        tty_encode_baud_rate(tty, speed, speed);
+
        if (tty->ops->set_termios)
                tty->ops->set_termios(tty, &old_termios);
-       //priv->io.speed = speed;
+
        mutex_unlock(&tty->termios_mutex);
 
        return 0;
 }
 
 
-/* Send one completely decapsulated can_frame to the network layer */
-static void sll_bump(struct sllin *sl)
+/* Send one can_frame to the network layer */
+static void sllin_send_canfr(struct sllin *sl, canid_t id, char *data, int len)
 {
-//     struct sk_buff *skb;
-//     struct can_frame cf;
-//     int i, dlc_pos, tmp;
-//     unsigned long ultmp;
-//     char cmd = sl->rbuff[0];
-//
-//     if ((cmd != 't') && (cmd != 'T') && (cmd != 'r') && (cmd != 'R'))
-//             return;
-//
-//     if (cmd & 0x20) /* tiny chars 'r' 't' => standard frame format */
-//             dlc_pos = 4; /* dlc position tiiid */
-//     else
-//             dlc_pos = 9; /* dlc position Tiiiiiiiid */
-//
-//     if (!((sl->rbuff[dlc_pos] >= '0') && (sl->rbuff[dlc_pos] < '9')))
-//             return;
-//
-//     cf.can_dlc = sl->rbuff[dlc_pos] - '0'; /* get can_dlc from ASCII val */
-//
-//     sl->rbuff[dlc_pos] = 0; /* terminate can_id string */
-//
-//     if (strict_strtoul(sl->rbuff+1, 16, &ultmp))
-//             return;
-//
-//     cf.can_id = ultmp;
-//
-//     if (!(cmd & 0x20)) /* NO tiny chars => extended frame format */
-//             cf.can_id |= CAN_EFF_FLAG;
-//
-//     if ((cmd | 0x20) == 'r') /* RTR frame */
-//             cf.can_id |= CAN_RTR_FLAG;
-//
-//     *(u64 *) (&cf.data) = 0; /* clear payload */
-//
-//     for (i = 0, dlc_pos++; i < cf.can_dlc; i++) {
-//
-//             tmp = asc2nibble(sl->rbuff[dlc_pos++]);
-//             if (tmp > 0x0F)
-//                     return;
-//             cf.data[i] = (tmp << 4);
-//             tmp = asc2nibble(sl->rbuff[dlc_pos++]);
-//             if (tmp > 0x0F)
-//                     return;
-//             cf.data[i] |= tmp;
-//     }
-//
-//
-//     skb = dev_alloc_skb(sizeof(struct can_frame));
-//     if (!skb)
-//             return;
-//
-//     skb->dev = sl->dev;
-//     skb->protocol = htons(ETH_P_CAN);
-//     skb->pkt_type = PACKET_BROADCAST;
-//     skb->ip_summed = CHECKSUM_UNNECESSARY;
-//     memcpy(skb_put(skb, sizeof(struct can_frame)),
-//            &cf, sizeof(struct can_frame));
-//     netif_rx(skb);
-//
-//     sl->dev->stats.rx_packets++;
-//     sl->dev->stats.rx_bytes += cf.can_dlc;
-}
-
+       struct sk_buff *skb;
+       struct can_frame cf;
 
- /************************************************************************
-  *                    STANDARD SLLIN ENCAPSULATION                     *
-  ************************************************************************/
+       cf.can_id = id;
+       cf.can_dlc = len;
+       if (cf.can_dlc > 0) {
+               memcpy(&cf.data, data, cf.can_dlc);
+       }
 
-/* Convert particular CAN frame into LIN frame and send it to TTY queue. */
-static void sll_encaps(struct sllin *sl, struct can_frame *cf)
-{
-       int actual, idx, i;
-       char lframe[16] = {0x00, 0x55}; /* Fake break, Sync byte */
-       struct tty_struct *tty = sl->tty;
+       skb = dev_alloc_skb(sizeof(struct can_frame));
+       if (!skb)
+               return;
 
-       pr_debug("sllin: %s() invoked\n", __FUNCTION__);
+       skb->dev = sl->dev;
+       skb->protocol = htons(ETH_P_CAN);
+       skb->pkt_type = PACKET_BROADCAST;
+       skb->ip_summed = CHECKSUM_UNNECESSARY;
+       memcpy(skb_put(skb, sizeof(struct can_frame)),
+              &cf, sizeof(struct can_frame));
+       netif_rx(skb);
 
-       /* We do care only about SFF frames */
-       if (cf->can_id & CAN_EFF_FLAG)
-               return;
+       sl->dev->stats.rx_packets++;
+       sl->dev->stats.rx_bytes += cf.can_dlc;
 
-       /* Send only header */
-       if (cf->can_id & CAN_RTR_FLAG) {
-               pr_debug("sllin: %s() RTR CAN frame\n", __FUNCTION__);
-               lframe[2] = (u8)cf->can_id; /* Get one byte LIN ID */
 
-               sltty_change_speed(tty, sl->lin_baud / 2);
-               tty->ops->write(tty, &lframe[0], 1);
-               sltty_change_speed(tty, sl->lin_baud);
-               tty->ops->write(tty, &lframe[1], 1);
-               tty->ops->write(tty, &lframe[2], 1);
-       } else {
-               pr_debug("sllin: %s() non-RTR CAN frame\n", __FUNCTION__);
-               /*      idx = strlen(sl->xbuff);
-
-                       for (i = 0; i < cf->can_dlc; i++)
-                       sprintf(&sl->xbuff[idx + 2*i], "%02X", cf->data[i]);
-
-                * Order of next two lines is *very* important.
-                * When we are sending a little amount of data,
-                * the transfer may be completed inside the ops->write()
-                * routine, because it's running with interrupts enabled.
-                * In this case we *never* got WRITE_WAKEUP event,
-                * if we did not request it before write operation.
-                *       14 Oct 1994  Dmitry Gorodchanin.
-
-                set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
-                actual = sl->tty->ops->write(sl->tty, sl->xbuff, strlen(sl->xbuff));
-                sl->xleft = strlen(sl->xbuff) - actual;
-                sl->xhead = sl->xbuff + actual;
-                sl->dev->stats.tx_bytes += cf->can_dlc;
-                */
-       }
+}
 
+static void sll_bump(struct sllin *sl)
+{
+       sllin_send_canfr(sl, sl->rx_buff[SLLIN_BUFF_ID] & SLLIN_ID_MASK,
+               sl->rx_buff + SLLIN_BUFF_DATA,
+               sl->rx_cnt - SLLIN_BUFF_DATA);
 }
 
 /*
@@ -322,24 +281,28 @@ 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->tx_req_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;
 }
@@ -441,16 +404,26 @@ static void sllin_receive_buf(struct tty_struct *tty,
                if (fp && *fp++) {
                        if (!test_and_set_bit(SLF_ERROR, &sl->flags))
                                sl->dev->stats.rx_errors++;
+                       printk(KERN_INFO "sllin_receive_buf char 0x%02x ignored "
+                               "due marker 0x%02x, flags 0x%lx\n",
+                               *cp, *(fp-1), sl->flags);
                        cp++;
                        continue;
                }
 
-               if (sl->rx_cnt < SLLIN_BUFF_LEN)  {
+               if (sl->rx_cnt < SLLIN_BUFF_LEN) {
+#ifndef BREAK_BY_BAUD
+                       /* We didn't receive Break character */
+                       if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
+                               sl->rx_buff[sl->rx_cnt++] = 0x00;
+                       }
+#endif
+                       printk(KERN_INFO "LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
                        sl->rx_buff[sl->rx_cnt++] = *cp++;
                }
        }
 
-       if(sl->rx_cnt >= sl->rx_expect) {
+       if (sl->rx_cnt >= sl->rx_expect) {
                set_bit(SLF_RXEVENT, &sl->flags);
                wake_up(&sl->kwt_wq);
                printk(KERN_INFO "sllin_receive_buf count %d, wakeup\n", sl->rx_cnt);
@@ -462,16 +435,45 @@ static void sllin_receive_buf(struct tty_struct *tty,
 /*****************************************
  *  sllin message helper routines
  *****************************************/
+void sllin_report_error(struct sllin *sl, int err)
+{
+       sllin_send_canfr(sl, 0 | CAN_EFF_FLAG | 
+               (err & ~SLLIN_ID_MASK), NULL, 0);
+}
+
+int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf)
+{
+       struct sllin_conf_entry *sce;
+       if (!(cf->can_id & SLLIN_LIN_ID_CONF))
+               return -1;
+
+       sce = &sl->linfr_cache[cf->can_id & SLLIN_ID_MASK];
+       printk(KERN_INFO "Setting frame cache with EFF CAN frame. "
+               "LIN ID = %d\n", cf->can_id & SLLIN_ID_MASK);
+
+       sce->dlc = (cf->can_dlc > 8) ? 8 : cf->can_dlc;
+       sce->frame_fl = (cf->can_id & ~SLLIN_ID_MASK) & CAN_EFF_MASK;
+       memcpy(sce->data, cf->data, cf->can_dlc);
+
+       return 0;
+}
+
+#define SLLIN_STPMSG_RESPONLY  (1) /* Message will be LIN Response only */
+#define SLLIN_STPMSG_CHCKSUMV1 (1 << 1)
+#define SLLIN_STPMSG_CHCKSUMV2 (1 << 2)
 
 int sllin_setup_msg(struct sllin *sl, int mode, int id,
                unsigned char *data, int len)
 {
-       if (id > 0x3f)
+       if (id > SLLIN_ID_MASK)
                return -1;
 
-       sl->rx_cnt = 0;
-       sl->tx_cnt = 0;
-       sl->rx_expect = 0;
+       if (!(mode & SLLIN_STPMSG_RESPONLY)) {
+               sl->rx_cnt = 0;
+               sl->tx_cnt = 0;
+               sl->rx_expect = 0;
+               sl->rx_lim = SLLIN_BUFF_LEN;
+       }
 
        sl->tx_buff[SLLIN_BUFF_BREAK] = 0;
        sl->tx_buff[SLLIN_BUFF_SYNC]  = 0x55;
@@ -480,7 +482,7 @@ int sllin_setup_msg(struct sllin *sl, int mode, int id,
 
        if ((data != NULL) && len) {
                int i;
-               unsigned csum  = 0;
+               unsigned csum = 0;
 
                sl->tx_lim += len;
                memcpy(sl->tx_buff + SLLIN_BUFF_DATA, data, len);
@@ -494,7 +496,7 @@ int sllin_setup_msg(struct sllin *sl, int mode, int id,
                sl->tx_buff[sl->tx_lim++] = csum;
        }
        if (len != 0)
-               sl->rx_lim += len + 1;
+               sl->rx_lim = SLLIN_BUFF_DATA + len + 1;
 
        return 0;
 }
@@ -506,11 +508,14 @@ int sllin_send_tx_buff(struct sllin *sl)
        int remains;
        int res;
 
+#ifdef BREAK_BY_BAUD
        if (sl->lin_state != SLSTATE_BREAK_SENT)
                remains = sl->tx_lim - sl->tx_cnt;
        else
                remains = 1;
-
+#else
+       remains = sl->tx_lim - sl->tx_cnt;
+#endif
 
        res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains);
        if (res < 0)
@@ -537,19 +542,20 @@ int sllin_send_tx_buff(struct sllin *sl)
        return 0;
 }
 
+#ifdef BREAK_BY_BAUD
 int sllin_send_break(struct sllin *sl)
 {
        struct tty_struct *tty = sl->tty;
-       unsigned long break_baud = sl->lin_baud;
+       unsigned long break_baud;
        int res;
 
-       //break_baud = (break_baud * 8) / 14;
-       break_baud /= 2;
-
+       break_baud = ((sl->lin_baud * 2) / 3);
        sltty_change_speed(tty, break_baud);
 
-       sl->rx_expect = SLLIN_BUFF_BREAK + 1;
+       tty->ops->flush_buffer(tty);
+       sl->rx_cnt = SLLIN_BUFF_BREAK;
 
+       sl->rx_expect = SLLIN_BUFF_BREAK + 1;
        sl->lin_state = SLSTATE_BREAK_SENT;
 
        res = sllin_send_tx_buff(sl);
@@ -560,6 +566,62 @@ int sllin_send_break(struct sllin *sl)
 
        return 0;
 }
+#else /* BREAK_BY_BAUD */
+
+int sllin_send_break(struct sllin *sl)
+{
+       struct tty_struct *tty = sl->tty;
+       unsigned long flags;    
+       int retval;
+       unsigned long break_baud;
+       unsigned long usleep_range_min;
+       unsigned long usleep_range_max;
+
+       break_baud = ((sl->lin_baud * 2) / 3);
+       sl->rx_cnt = SLLIN_BUFF_BREAK;
+       sl->rx_expect = SLLIN_BUFF_BREAK + 1;
+       sl->lin_state = SLSTATE_BREAK_SENT;
+
+       /* Do the break ourselves; Inspired by 
+          http://lxr.linux.no/#linux+v3.1.2/drivers/tty/tty_io.c#L2452 */
+       retval = tty->ops->break_ctl(tty, -1);
+       if (retval)
+               return retval;
+
+       //udelay(712);
+       usleep_range_min = (1000000l * SLLIN_SAMPLES_PER_CHAR) / break_baud;
+       usleep_range_max = usleep_range_min + 50;
+       usleep_range(usleep_range_min, usleep_range_max);
+
+       retval = tty->ops->break_ctl(tty, 0);
+       usleep_range_min = (1000000l * 1 /* 1 bit */) / break_baud;
+       usleep_range_max = usleep_range_min + 30;
+       usleep_range(usleep_range_min, usleep_range_max);
+       
+       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);
+
+       return 0;
+}
+#endif /* BREAK_BY_BAUD */
+
+
+static enum hrtimer_restart sllin_rx_timeout_handler(struct hrtimer *hrtimer)
+{
+       struct sllin *sl = container_of(hrtimer, struct sllin, rx_timer);
+
+       sllin_report_error(sl, SLLIN_ERR_RX_TIMEOUT);
+       set_bit(SLF_TMOUTEVENT, &sl->flags);
+       wake_up(&sl->kwt_wq);
+
+       return HRTIMER_NORESTART;
+}
+
 
 /*****************************************
  *  sllin_kwthread - kernel worker thread
@@ -569,30 +631,35 @@ int sllin_kwthread(void *ptr)
 {
        struct sllin *sl = (struct sllin *)ptr;
        struct tty_struct *tty = sl->tty;
+       struct sched_param schparam = { .sched_priority = 40 };
        int res;
+       struct can_frame *cf;
+       u8 *lin_data;
+       int lin_dlc;
+       int tx_bytes = 0; /* Used for Network statistics */
+
 
        printk(KERN_INFO "sllin: sllin_kwthread started.\n");
+       sched_setscheduler(current, SCHED_FIFO, &schparam);
 
        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) {
+                       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));
+                       test_bit(SLF_TXEVENT, &sl->flags) ||
+                       test_bit(SLF_TMOUTEVENT, &sl->flags) ||
+                       (((sl->lin_state == SLSTATE_IDLE) || 
+                               (sl->lin_state == SLSTATE_RESPONSE_WAIT)) 
+                               && test_bit(SLF_MSGEVENT, &sl->flags)));
 
                if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) {
                        printk(KERN_INFO "sllin_kthread RXEVENT \n");
@@ -602,33 +669,183 @@ int sllin_kwthread(void *ptr)
                        printk(KERN_INFO "sllin_kthread TXEVENT \n");
                }
 
+               if (test_and_clear_bit(SLF_TMOUTEVENT, &sl->flags)) {
+                       printk(KERN_INFO "sllin_kthread TMOUTEVENT \n");
+                       sl->rx_cnt = 0;
+                       sl->rx_expect = 0;
+                       sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
+                       sl->tx_cnt = 0;
+                       sl->tx_lim = 0;
+                       sl->id_to_send = false;
+                       sl->data_to_send = false;
+                       
+                       sl->lin_state = SLSTATE_IDLE;
+               }
+
+               if ((sl->lin_state == SLSTATE_IDLE) && test_bit(SLF_MSGEVENT, &sl->flags)) {
+                       cf = (struct can_frame *)sl->tx_req_skb->data;
+
+                       /* EFF CAN frame -> "Configuration" frame */
+                       if (cf->can_id & CAN_EFF_FLAG) {
+                               sllin_configure_frame_cache(sl, cf);
+                               goto free_skb;
+                       } /* SFF RTR CAN frame -> LIN header */ 
+                       else if (cf->can_id & CAN_RTR_FLAG) {
+                               printk(KERN_INFO "%s: RTR SFF CAN frame, ID = %x\n",
+                                       __FUNCTION__, cf->can_id & SLLIN_ID_MASK);
+
+                               /* Is there Slave response in linfr_cache to be sent? */
+                               if ((sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].frame_fl & 
+                                       SLLIN_LOC_SLAVE_CACHE) 
+                                       && (sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].dlc > 0)) {
+                                       
+                                       printk(KERN_INFO "Sending LIN response from linfr_cache\n");
+                                       lin_data = &sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].data;
+                                       lin_dlc = sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].dlc;
+                               } else {
+                                       lin_data = NULL;
+                                       lin_dlc = sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].dlc;
+                               }
+                       } else { /* SFF NON-RTR CAN frame -> LIN header + LIN response */
+                               printk(KERN_INFO "%s: NON-RTR SFF CAN frame, ID = %x\n",
+                                       __FUNCTION__, (int)cf->can_id & SLLIN_ID_MASK);
+
+                               lin_data = cf->data;
+                               lin_dlc = tx_bytes = cf->can_dlc;
+                       }
+
+                       if (sllin_setup_msg(sl, 0, cf->can_id & SLLIN_ID_MASK,
+                               lin_data, lin_dlc) != -1) {
+
+                               sl->id_to_send = true;
+                               sl->data_to_send = (lin_data != NULL) ? true : false;
+                               sl->resp_len_known = (lin_dlc > 0) ? true : false;
+                               sl->dev->stats.tx_packets++;
+                               sl->dev->stats.tx_bytes += tx_bytes;
+                       }
+
+               free_skb:
+                       clear_bit(SLF_MSGEVENT, &sl->flags);
+                       kfree_skb(sl->tx_req_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;
 
                                res = sltty_change_speed(tty, sl->lin_baud);
+#endif
 
+                               sl->lin_state = SLSTATE_ID_SENT;
                                sllin_send_tx_buff(sl);
+                               break;
 
-                               sl->lin_state = SLSTATE_ID_SENT;
+                       case SLSTATE_ID_SENT:
+                               sl->id_to_send = false;
+                               if (sl->data_to_send) {
+                                       sllin_send_tx_buff(sl);
+                                       sl->lin_state = SLSTATE_RESPONSE_SENT;
+                                       sl->rx_expect = sl->tx_lim;
+                                       goto slstate_response_sent;
+                               } else {
+                                       if (sl->resp_len_known) {
+                                               sl->rx_expect = sl->rx_lim;
+                                       } else {
+                                               sl->rx_expect = SLLIN_BUFF_DATA + 2;
+                                       }
+                                       sl->lin_state = SLSTATE_RESPONSE_WAIT;
+                                       /* If we don't receive anything, timer will "unblock" us */
+                                       hrtimer_start(&sl->rx_timer, 
+                                               ktime_add(ktime_get(), sl->rx_timer_timeout),
+                                               HRTIMER_MODE_ABS);
+                                       goto slstate_response_wait;
+                               }
+                               break;
 
+                       case SLSTATE_RESPONSE_WAIT:
+                       slstate_response_wait:
+                               if (test_bit(SLF_MSGEVENT, &sl->flags)) {
+                                       cf = (struct can_frame *)sl->tx_req_skb->data;
+
+                                       /* EFF CAN frame -> "Configuration" frame */
+                                       if (cf->can_id & CAN_EFF_FLAG) {
+                                               sllin_configure_frame_cache(sl, cf);
+
+                                               clear_bit(SLF_MSGEVENT, &sl->flags);
+                                               kfree_skb(sl->tx_req_skb);
+                                               netif_wake_queue(sl->dev);
+                                       } else {
+                                               unsigned char *lin_buff;
+                                               lin_buff = (sl->lin_master) ? sl->tx_buff : sl->rx_buff;
+                                               if (cf->can_id == lin_buff[SLLIN_BUFF_ID] & SLLIN_ID_MASK) {
+                                                       if (sllin_setup_msg(sl, SLLIN_STPMSG_RESPONLY, 
+                                                               cf->can_id & SLLIN_ID_MASK,
+                                                               cf->data, cf->can_dlc) != -1) {
+
+                                                               sl->rx_expect = sl->tx_lim;
+                                                               sl->data_to_send = true;
+                                                               sl->dev->stats.tx_packets++;
+                                                               sl->dev->stats.tx_bytes += tx_bytes;
+
+                                                               if (!sl->lin_master) {
+                                                                       sl->tx_cnt = SLLIN_BUFF_DATA;
+                                                               }
+                                                               
+                                                               sllin_send_tx_buff(sl);
+                                                               clear_bit(SLF_MSGEVENT, &sl->flags);
+                                                               kfree_skb(sl->tx_req_skb);
+                                                               netif_wake_queue(sl->dev);
+
+                                                               sl->lin_state = SLSTATE_RESPONSE_SENT;
+                                                               goto slstate_response_sent;
+                                                       }
+                                               } else {
+                                                       sl->lin_state = SLSTATE_RESPONSE_WAIT_BUS;
+                                               }
+                                       }
+                               }
+
+                       case SLSTATE_RESPONSE_WAIT_BUS:
+                               if (sl->rx_cnt < sl->rx_expect)
+                                       continue;
+                       
+                               hrtimer_cancel(&sl->rx_timer);
+                               printk(KERN_INFO "sllin: response received ID %d len %d\n",
+                                       sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
+                               // FIXME: check checksum in sl->rx_buff
+
+                               // send CAN non-RTR frame with data
+                               printk(KERN_INFO "sllin: sending NON-RTR CAN frame with LIN payload.");
+                               sll_bump(sl); //send packet to the network layer
+                               sl->id_to_send = false;
+                               sl->lin_state = SLSTATE_IDLE;
                                break;
-                       case SLSTATE_ID_SENT:
-                               sl->id_to_send = 0;
+                       
+                       case SLSTATE_RESPONSE_SENT:
+                       slstate_response_sent:
+                               if (sl->rx_cnt < sl->tx_lim)
+                                       continue;
+                               
+                               sll_bump(sl); //send packet to the network layer
+                               printk(KERN_INFO "sllin: response sent ID %d len %d\n",
+                                       sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
+
+                               sl->id_to_send = false;
                                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 */
        }
 
-
+       hrtimer_cancel(&sl->rx_timer);
        printk(KERN_INFO "sllin: sllin_kwthread stopped.\n");
 
        return 0;
@@ -652,7 +869,7 @@ static void sll_sync(void)
                        break;
 
                sl = netdev_priv(dev);
-               if (sl->tty || sl->leased)
+               if (sl->tty)
                        continue;
                if (dev->flags & IFF_UP)
                        dev_close(dev);
@@ -700,7 +917,6 @@ static struct sllin *sll_alloc(dev_t line)
        }
 
        sl = netdev_priv(dev);
-
        /* Initialize channel control data */
        sl->magic = SLLIN_MAGIC;
        sl->dev = dev;
@@ -760,16 +976,27 @@ static int sllin_open(struct tty_struct *tty)
 
        if (!test_bit(SLF_INUSE, &sl->flags)) {
                /* Perform the low-level SLLIN initialization. */
-               sl->rx_cnt    = 0;
+               sl->lin_master = true;
+
+               sl->rx_cnt = 0;
                sl->rx_expect = 0;
-               sl->tx_cnt    = 0;
-               sl->tx_lim    = 0;
+               sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
+               sl->tx_cnt = 0;
+               sl->tx_lim = 0;
+               sl->id_to_send = false;
+               sl->data_to_send = false;
 
-               sl->lin_baud  = 2400;
+               sl->lin_baud  = 19200;
 
-               sl->lin_master = 1;
                sl->lin_state = SLSTATE_IDLE;
 
+               hrtimer_init(&sl->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+               sl->rx_timer.function = sllin_rx_timeout_handler;
+               /* timeval_to_ktime(msg_head->ival1); */
+               sl->rx_timer_timeout = ns_to_ktime(
+                       (1000000000l / sl->lin_baud) * 
+                       SLLIN_SAMPLES_PER_CHAR * SLLIN_CHARS_TO_TIMEOUT); 
                set_bit(SLF_INUSE, &sl->flags);
 
                init_waitqueue_head(&sl->kwt_wq);
@@ -826,8 +1053,6 @@ static void sllin_close(struct tty_struct *tty)
 
        tty->disc_data = NULL;
        sl->tty = NULL;
-       if (!sl->leased)
-               sl->line = 0;
 
        /* Flush network side */
        unregister_netdev(sl->dev);