#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
#define SLLIN_BUFF_ID 2
#define SLLIN_BUFF_DATA 3
+#define SLLIN_ID_MASK 0x3f
+
enum slstate {
SLSTATE_IDLE = 0,
SLSTATE_BREAK_SENT,
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 */
};
/* Send one completely decapsulated can_frame to the network layer */
static void sll_bump(struct sllin *sl)
{
-// 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;
+
+ cf.can_id = sl->rx_buff[SLLIN_BUFF_ID] & SLLIN_ID_MASK;
+ cf.can_dlc = sl->rx_cnt - SLLIN_BUFF_DATA;
+ memcpy(&cf.data, sl->rx_buff + SLLIN_BUFF_DATA, cf.can_dlc);
+
+ 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;
}
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;
+ 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;
}
}
#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
*****************************************/
wait_event_killable(sl->kwt_wq, kthread_should_stop() ||
test_bit(SLF_RXEVENT, &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 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;
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",
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;
}
}
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
+ 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_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;
- /* 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;
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 12
+ 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);