/*
* 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
#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
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
#define SLLIN_BUFF_ID 2
#define SLLIN_BUFF_DATA 3
+#define SLLIN_ID_MASK 0x3f
+#define SLLIN_ID_MAX SLLIN_ID_MASK
+
enum slstate {
SLSTATE_IDLE = 0,
SLSTATE_BREAK_SENT,
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))
+ 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;
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 */
+
+ 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;
/* 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);
- /************************************************************************
- * STANDARD SLLIN ENCAPSULATION *
- ************************************************************************/
+ skb = dev_alloc_skb(sizeof(struct can_frame));
+ if (!skb)
+ return;
-/* 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;
-//
-// pr_debug("sllin: %s() invoked\n", __FUNCTION__);
-//
-// /* We do care only about SFF frames */
-// if (cf->can_id & CAN_EFF_FLAG)
-// return;
-//
-// /* 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 / 3);
-// 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;
-// */
-// }
-//
+ 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;
}
/*
/*****************************************
* sllin message helper routines
*****************************************/
+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;
+}
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
*****************************************/
struct sched_param schparam = { .sched_priority = 40 };
int res;
struct can_frame *cf;
+ char *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);
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;
- /* 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;
+ /* 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 = 0;
}
- } else {
- printk(KERN_INFO "%s: NON-RTR CAN frame, ID = %x\n",
- __FUNCTION__, (int)cf->can_id & CAN_SFF_MASK);
+ } 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);
- if (sllin_setup_msg(sl, 0, cf->can_id & CAN_SFF_MASK,
- cf->data, cf->can_dlc) != -1) {
- sl->id_to_send = true;
- }
+ lin_data = cf->data;
+ lin_dlc = tx_bytes = cf->can_dlc;
}
- release_skb:
+ 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_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->rec_skb);
netif_wake_queue(sl->dev);
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);
+ // 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_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;
}
sl = netdev_priv(dev);
-
/* Initialize channel control data */
sl->magic = SLLIN_MAGIC;
sl->dev = dev;
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);
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