#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
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 */
unsigned long flags; /* Flag values/ mode etc */
#define SLF_INUSE 0 /* Channel in use */
#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 */
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 *rec_skb; /* Socket buffer with received CAN frame */
};
static struct net_device **sllin_devs;
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;
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;
}
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--) {
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;
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;
}
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);
}
#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);
+
+ set_bit(SLF_TMOUTEVENT, &sl->flags);
+ wake_up(&sl->kwt_wq);
+
+ return HRTIMER_NORESTART;
+}
+
+
/*****************************************
* sllin_kwthread - kernel worker thread
*****************************************/
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);
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) {
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) && test_bit(SLF_MSGEVENT, &sl->flags)));
if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) {
printk(KERN_INFO "sllin_kthread RXEVENT \n");
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->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;
+ sl->data_to_send = false;
+ }
+ } 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;
+ sl->data_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
break;
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 {
+ 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 (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);
+ // check checksum in sl->rx_buff
+ // send CAN non-RTR frame with data
+ sl->id_to_send = false;
+ sl->lin_state = SLSTATE_IDLE;
+ break;
+
+ case SLSTATE_RESPONSE_SENT:
+ slstate_response_sent:
+ if (sl->rx_cnt < sl->tx_lim)
+ continue;
+
+ 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;
/* 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;
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->rx_lim = 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 = 19200;
- sl->lin_master = 1;
sl->lin_state = SLSTATE_IDLE;
+#define SAMPLES_PER_CHAR 10
+#define CHARS_TO_TIMEOUT 6
+ 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(
+ (1000000000 / sl->lin_baud) *
+ SAMPLES_PER_CHAR * CHARS_TO_TIMEOUT);
+
set_bit(SLF_INUSE, &sl->flags);
init_waitqueue_head(&sl->kwt_wq);
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