2 * sllin.c - serial line LIN interface driver (using tty line discipline)
4 * This file is derived from drivers/net/can/slcan.c
5 * slcan.c Author: Oliver Hartkopp <socketcan@hartkopp.net>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307. You can also get it
20 * at http://www.gnu.org/licenses/gpl.html
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
35 * Send feedback to <socketcan-users@lists.berlios.de>
39 #define DEBUG 1 /* Enables pr_debug() printouts */
41 #include <linux/module.h>
42 #include <linux/moduleparam.h>
44 #include <asm/system.h>
45 #include <linux/uaccess.h>
46 #include <linux/bitops.h>
47 #include <linux/string.h>
48 #include <linux/tty.h>
49 #include <linux/errno.h>
50 #include <linux/netdevice.h>
51 #include <linux/skbuff.h>
52 #include <linux/rtnetlink.h>
53 #include <linux/if_arp.h>
54 #include <linux/if_ether.h>
55 #include <linux/sched.h>
56 #include <linux/delay.h>
57 #include <linux/init.h>
58 #include <linux/can.h>
59 #include <linux/kthread.h>
60 #include <linux/hrtimer.h>
62 /* Should be in include/linux/tty.h */
64 /* -------------------------------- */
66 static __initdata const char banner[] =
67 KERN_INFO "sllin: serial line LIN interface driver\n";
69 MODULE_ALIAS_LDISC(N_SLLIN);
70 MODULE_DESCRIPTION("serial line LIN interface");
71 MODULE_LICENSE("GPL");
74 #define SLLIN_MAGIC 0x53CA
75 /* #define BREAK_BY_BAUD */
77 static int maxdev = 10; /* MAX number of SLLIN channels;
78 This can be overridden with
79 insmod sllin.ko maxdev=nnn */
80 module_param(maxdev, int, 0);
81 MODULE_PARM_DESC(maxdev, "Maximum number of sllin interfaces");
83 /* maximum buffer len to store whole LIN message*/
84 #define SLLIN_DATA_MAX 8
85 #define SLLIN_BUFF_LEN (1 /*break*/ + 1 /*sync*/ + 1 /*ID*/ + \
86 SLLIN_DATA_MAX + 1 /*checksum*/)
87 #define SLLIN_BUFF_BREAK 0
88 #define SLLIN_BUFF_SYNC 1
89 #define SLLIN_BUFF_ID 2
90 #define SLLIN_BUFF_DATA 3
92 #define SLLIN_ID_MASK 0x3f
93 #define SLLIN_ID_MAX SLLIN_ID_MASK
94 #define SLLIN_CTRL_FRAME CAN_EFF_FLAG
96 #define SLLIN_SAMPLES_PER_CHAR 10
97 #define SLLIN_CHARS_TO_TIMEOUT 12
103 SLSTATE_RESPONSE_WAIT, /* Wait for response */
104 SLSTATE_RESPONSE_WAIT_BUS, /* Wait for response from LIN bus
105 only (CAN frames from network stack
106 are not processed in this moment) */
107 SLSTATE_RESPONSE_SENT,
110 struct sllin_conf_entry {
111 int dlc; /* Length of data in LIN frame */
112 #define SLLIN_CANFR_FLAGS_OFFS 6 /* Lower 6 bits in can_id correspond to LIN ID */
113 /* Save configuration for particular LIN ID */
114 #define SLLIN_LIN_ID_CONF (1 << SLLIN_CANFR_FLAGS_OFFS)
115 /* Publisher of particular LIN response is SLLIN Master */
116 #define SLLIN_SRC_MASTER (1 << (SLLIN_CANFR_FLAGS_OFFS + 1))
117 #define SLLIN_SRC_SLAVE (1 << (SLLIN_CANFR_FLAGS_OFFS + 2))
118 #define SLLIN_SLAVE_LOCAL (1 << (SLLIN_CANFR_FLAGS_OFFS + 3))
119 #define SLLIN_SLAVE_REMOTE (1 << (SLLIN_CANFR_FLAGS_OFFS + 4))
120 #define SLLIN_LOC_SLAVE_CACHE (1 << (SLLIN_CANFR_FLAGS_OFFS + 5))
121 #define SLLIN_CHECKSUM_EXTENDED (1 << (SLLIN_CANFR_FLAGS_OFFS + 6))
123 #define SLLIN_ERR_RX_TIMEOUT (1 << (SLLIN_CANFR_FLAGS_OFFS + 7))
124 #define SLLIN_ERR_CHECKSUM (1 << (SLLIN_CANFR_FLAGS_OFFS + 8))
125 //#define SLLIN_ERR_FRAMING (1 << (SLLIN_CANFR_FLAGS_OFFS + 9))
127 canid_t frame_fl; /* LIN frame flags. Passed from userspace as canid_t data type */
128 u8 data[8]; /* LIN frame data payload */
134 /* Various fields. */
135 struct tty_struct *tty; /* ptr to TTY structure */
136 struct net_device *dev; /* easy for intr handling */
139 /* LIN message buffer and actual processed data counts */
140 unsigned char rx_buff[SLLIN_BUFF_LEN]; /* LIN Rx buffer */
141 unsigned char tx_buff[SLLIN_BUFF_LEN]; /* LIN Tx buffer */
142 int rx_expect; /* expected number of Rx chars */
143 int rx_lim; /* maximum Rx chars for current frame */
144 int rx_cnt; /* message buffer Rx fill level */
145 int tx_lim; /* actual limit of bytes to Tx */
146 int tx_cnt; /* number of already Tx bytes */
147 char lin_master; /* node is a master node */
148 int lin_baud; /* LIN baudrate */
149 int lin_state; /* state */
150 char id_to_send; /* there is ID to be sent */
151 char data_to_send; /* there are data to be sent */
152 char resp_len_known; /* Length of the response is known */
154 unsigned long flags; /* Flag values/ mode etc */
155 #define SLF_INUSE 0 /* Channel in use */
156 #define SLF_ERROR 1 /* Parity, etc. error */
157 #define SLF_RXEVENT 2 /* Rx wake event */
158 #define SLF_TXEVENT 3 /* Tx wake event */
159 #define SLF_MSGEVENT 4 /* CAN message to sent */
160 #define SLF_TMOUTEVENT 5 /* Timeout on received data */
163 struct task_struct *kwthread;
164 wait_queue_head_t kwt_wq;
165 struct hrtimer rx_timer; /* RX timeout timer */
166 ktime_t rx_timer_timeout; /* RX timeout timer value */
167 struct sk_buff *tx_req_skb; /* Socket buffer with CAN frame received
170 struct sllin_conf_entry linfr_cache[SLLIN_ID_MAX + 1]; /* List with configurations for
171 each of 0 to SLLIN_ID_MAX LIN IDs */
174 static struct net_device **sllin_devs;
175 static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf);
178 const unsigned char sllin_id_parity_table[] = {
179 0x80,0xc0,0x40,0x00,0xc0,0x80,0x00,0x40,
180 0x00,0x40,0xc0,0x80,0x40,0x00,0x80,0xc0,
181 0x40,0x00,0x80,0xc0,0x00,0x40,0xc0,0x80,
182 0xc0,0x80,0x00,0x40,0x80,0xc0,0x40,0x00,
183 0x00,0x40,0xc0,0x80,0x40,0x00,0x80,0xc0,
184 0x80,0xc0,0x40,0x00,0xc0,0x80,0x00,0x40,
185 0xc0,0x80,0x00,0x40,0x80,0xc0,0x40,0x00,
186 0x40,0x00,0x80,0xc0,0x00,0x40,0xc0,0x80
189 static int sltty_change_speed(struct tty_struct *tty, unsigned speed)
191 struct ktermios old_termios;
194 mutex_lock(&tty->termios_mutex);
196 old_termios = *(tty->termios);
197 cflag = tty->termios->c_cflag;
198 cflag &= ~(CBAUD | CIBAUD);
200 tty->termios->c_cflag = cflag;
202 tty_encode_baud_rate(tty, speed, speed);
204 if (tty->ops->set_termios)
205 tty->ops->set_termios(tty, &old_termios);
207 mutex_unlock(&tty->termios_mutex);
213 /* Send one can_frame to the network layer */
214 static void sllin_send_canfr(struct sllin *sl, canid_t id, char *data, int len)
221 if (cf.can_dlc > 0) {
222 memcpy(&cf.data, data, cf.can_dlc);
225 skb = dev_alloc_skb(sizeof(struct can_frame));
230 skb->protocol = htons(ETH_P_CAN);
231 skb->pkt_type = PACKET_BROADCAST;
232 skb->ip_summed = CHECKSUM_UNNECESSARY;
233 memcpy(skb_put(skb, sizeof(struct can_frame)),
234 &cf, sizeof(struct can_frame));
237 sl->dev->stats.rx_packets++;
238 sl->dev->stats.rx_bytes += cf.can_dlc;
243 static void sll_bump(struct sllin *sl)
245 sllin_send_canfr(sl, sl->rx_buff[SLLIN_BUFF_ID] & SLLIN_ID_MASK,
246 sl->rx_buff + SLLIN_BUFF_DATA,
247 sl->rx_cnt - SLLIN_BUFF_DATA - 1); /* without checksum */
251 * Called by the driver when there's room for more data. If we have
252 * more packets to send, we send them here.
254 static void sllin_write_wakeup(struct tty_struct *tty)
258 struct sllin *sl = (struct sllin *) tty->disc_data;
260 /* First make sure we're connected. */
261 if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
264 if (sl->lin_state != SLSTATE_BREAK_SENT)
265 remains = sl->tx_lim - sl->tx_cnt;
267 remains = SLLIN_BUFF_BREAK + 1 - sl->tx_cnt;
270 actual = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, sl->tx_cnt - sl->tx_lim);
271 sl->tx_cnt += actual;
273 if (sl->tx_cnt < sl->tx_lim) {
274 pr_debug("sllin: sllin_write_wakeup sent %d, remains %d, waiting\n",
275 sl->tx_cnt, sl->tx_lim - sl->tx_cnt);
280 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
281 set_bit(SLF_TXEVENT, &sl->flags);
282 wake_up(&sl->kwt_wq);
284 pr_debug("sllin: sllin_write_wakeup sent %d, wakeup\n", sl->tx_cnt);
287 /* Send a can_frame to a TTY queue. */
288 static netdev_tx_t sll_xmit(struct sk_buff *skb, struct net_device *dev)
290 struct sllin *sl = netdev_priv(dev);
291 struct can_frame *cf;
293 if (skb->len != sizeof(struct can_frame))
296 spin_lock(&sl->lock);
297 if (!netif_running(dev)) {
298 printk(KERN_WARNING "%s: xmit: iface is down\n", dev->name);
301 if (sl->tty == NULL) {
305 cf = (struct can_frame *) skb->data;
306 if (cf->can_id & SLLIN_CTRL_FRAME) {
307 sllin_configure_frame_cache(sl, cf);
308 goto free_out_unlock;
311 netif_stop_queue(sl->dev);
313 sl->tx_req_skb = skb;
314 set_bit(SLF_MSGEVENT, &sl->flags);
315 wake_up(&sl->kwt_wq);
316 spin_unlock(&sl->lock);
321 spin_unlock(&sl->lock);
328 /******************************************
329 * Routines looking at netdevice side.
330 ******************************************/
332 /* Netdevice UP -> DOWN routine */
333 static int sll_close(struct net_device *dev)
335 struct sllin *sl = netdev_priv(dev);
337 spin_lock_bh(&sl->lock);
339 /* TTY discipline is running. */
340 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
342 netif_stop_queue(dev);
345 spin_unlock_bh(&sl->lock);
350 /* Netdevice DOWN -> UP routine */
351 static int sll_open(struct net_device *dev)
353 struct sllin *sl = netdev_priv(dev);
355 pr_debug("sllin: %s() invoked\n", __FUNCTION__);
360 sl->flags &= (1 << SLF_INUSE);
361 netif_start_queue(dev);
365 /* Hook the destructor so we can free sllin devs at the right point in time */
366 static void sll_free_netdev(struct net_device *dev)
368 int i = dev->base_addr;
370 sllin_devs[i] = NULL;
373 static const struct net_device_ops sll_netdev_ops = {
374 .ndo_open = sll_open,
375 .ndo_stop = sll_close,
376 .ndo_start_xmit = sll_xmit,
379 static void sll_setup(struct net_device *dev)
381 dev->netdev_ops = &sll_netdev_ops;
382 dev->destructor = sll_free_netdev;
384 dev->hard_header_len = 0;
386 dev->tx_queue_len = 10;
388 dev->mtu = sizeof(struct can_frame);
389 dev->type = ARPHRD_CAN;
391 /* New-style flags. */
392 dev->flags = IFF_NOARP;
393 dev->features = NETIF_F_NO_CSUM;
396 /******************************************
397 Routines looking at TTY side.
398 ******************************************/
401 * Handle the 'receiver data ready' interrupt.
402 * This function is called by the 'tty_io' module in the kernel when
403 * a block of SLLIN data has been received, which can now be decapsulated
404 * and sent on to some IP layer for further processing. This will not
405 * be re-entered while running but other ldisc functions may be called
409 static void sllin_receive_buf(struct tty_struct *tty,
410 const unsigned char *cp, char *fp, int count)
412 struct sllin *sl = (struct sllin *) tty->disc_data;
414 pr_debug("sllin: sllin_receive_buf invoked\n");
416 if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
419 /* Read the characters out of the buffer */
422 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
423 sl->dev->stats.rx_errors++;
424 pr_debug("sllin: sllin_receive_buf char 0x%02x ignored "
425 "due marker 0x%02x, flags 0x%lx\n",
426 *cp, *(fp-1), sl->flags);
431 if (sl->rx_cnt < SLLIN_BUFF_LEN) {
432 #ifndef BREAK_BY_BAUD
433 /* We didn't receive Break character */
434 if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
435 sl->rx_buff[sl->rx_cnt++] = 0x00;
438 pr_debug("sllin: LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
439 sl->rx_buff[sl->rx_cnt++] = *cp++;
443 if (sl->rx_cnt >= sl->rx_expect) {
444 set_bit(SLF_RXEVENT, &sl->flags);
445 wake_up(&sl->kwt_wq);
446 pr_debug("sllin: sllin_receive_buf count %d, wakeup\n", sl->rx_cnt);
448 pr_debug("sllin: sllin_receive_buf count %d, waiting\n", sl->rx_cnt);
452 /*****************************************
453 * sllin message helper routines
454 *****************************************/
455 void sllin_report_error(struct sllin *sl, int err)
457 sllin_send_canfr(sl, 0 | CAN_EFF_FLAG |
458 (err & ~SLLIN_ID_MASK), NULL, 0);
461 static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf)
463 struct sllin_conf_entry *sce;
464 if (!(cf->can_id & SLLIN_LIN_ID_CONF))
467 sce = &sl->linfr_cache[cf->can_id & SLLIN_ID_MASK];
468 pr_debug("sllin: Setting frame cache with EFF CAN frame. "
469 "LIN ID = %d\n", cf->can_id & SLLIN_ID_MASK);
471 sce->dlc = cf->can_dlc;
472 if (sce->dlc > SLLIN_DATA_MAX)
473 sce->dlc = SLLIN_DATA_MAX;
475 sce->frame_fl = (cf->can_id & ~SLLIN_ID_MASK) & CAN_EFF_MASK;
476 memcpy(sce->data, cf->data, cf->can_dlc);
481 static inline unsigned sllin_checksum(unsigned char *data, int length, int enhanced_fl)
492 for (; i < length; i++) {
501 #define SLLIN_STPMSG_RESPONLY (1) /* Message will be LIN Response only */
502 #define SLLIN_STPMSG_CHCKSUM_CLS (1 << 1)
503 #define SLLIN_STPMSG_CHCKSUM_ENH (1 << 2)
505 int sllin_setup_msg(struct sllin *sl, int mode, int id,
506 unsigned char *data, int len)
508 if (id > SLLIN_ID_MASK)
511 if (!(mode & SLLIN_STPMSG_RESPONLY)) {
515 sl->rx_lim = SLLIN_BUFF_LEN;
518 sl->tx_buff[SLLIN_BUFF_BREAK] = 0;
519 sl->tx_buff[SLLIN_BUFF_SYNC] = 0x55;
520 sl->tx_buff[SLLIN_BUFF_ID] = id | sllin_id_parity_table[id];
521 sl->tx_lim = SLLIN_BUFF_DATA;
523 if ((data != NULL) && len) {
525 memcpy(sl->tx_buff + SLLIN_BUFF_DATA, data, len);
526 sl->tx_buff[sl->tx_lim++] = sllin_checksum(sl->tx_buff,
527 sl->tx_lim, mode & SLLIN_STPMSG_CHCKSUM_ENH);
530 sl->rx_lim = SLLIN_BUFF_DATA + len + 1;
536 int sllin_send_tx_buff(struct sllin *sl)
538 struct tty_struct *tty = sl->tty;
543 if (sl->lin_state != SLSTATE_BREAK_SENT)
544 remains = sl->tx_lim - sl->tx_cnt;
548 remains = sl->tx_lim - sl->tx_cnt;
551 res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains);
559 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
560 res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains);
562 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
570 pr_debug("sllin: sllin_send_tx_buff sent %d, remains %d\n",
571 sl->tx_cnt, remains);
577 int sllin_send_break(struct sllin *sl)
579 struct tty_struct *tty = sl->tty;
580 unsigned long break_baud;
583 break_baud = ((sl->lin_baud * 2) / 3);
584 sltty_change_speed(tty, break_baud);
586 tty->ops->flush_buffer(tty);
587 sl->rx_cnt = SLLIN_BUFF_BREAK;
589 sl->rx_expect = SLLIN_BUFF_BREAK + 1;
590 sl->lin_state = SLSTATE_BREAK_SENT;
592 res = sllin_send_tx_buff(sl);
594 sl->lin_state = SLSTATE_IDLE;
600 #else /* BREAK_BY_BAUD */
602 int sllin_send_break(struct sllin *sl)
604 struct tty_struct *tty = sl->tty;
606 unsigned long break_baud;
607 unsigned long usleep_range_min;
608 unsigned long usleep_range_max;
610 break_baud = ((sl->lin_baud * 2) / 3);
611 sl->rx_cnt = SLLIN_BUFF_BREAK;
612 sl->rx_expect = SLLIN_BUFF_BREAK + 1;
613 sl->lin_state = SLSTATE_BREAK_SENT;
615 /* Do the break ourselves; Inspired by
616 http://lxr.linux.no/#linux+v3.1.2/drivers/tty/tty_io.c#L2452 */
617 retval = tty->ops->break_ctl(tty, -1);
622 usleep_range_min = (1000000l * SLLIN_SAMPLES_PER_CHAR) / break_baud;
623 usleep_range_max = usleep_range_min + 50;
624 usleep_range(usleep_range_min, usleep_range_max);
626 retval = tty->ops->break_ctl(tty, 0);
627 usleep_range_min = (1000000l * 1 /* 1 bit */) / break_baud;
628 usleep_range_max = usleep_range_min + 30;
629 usleep_range(usleep_range_min, usleep_range_max);
631 tty->ops->flush_buffer(tty);
633 sl->tx_cnt = SLLIN_BUFF_SYNC;
635 pr_debug("sllin: Break sent.\n");
636 set_bit(SLF_RXEVENT, &sl->flags);
637 wake_up(&sl->kwt_wq);
641 #endif /* BREAK_BY_BAUD */
644 static enum hrtimer_restart sllin_rx_timeout_handler(struct hrtimer *hrtimer)
646 struct sllin *sl = container_of(hrtimer, struct sllin, rx_timer);
648 sllin_report_error(sl, SLLIN_ERR_RX_TIMEOUT);
649 set_bit(SLF_TMOUTEVENT, &sl->flags);
650 wake_up(&sl->kwt_wq);
652 return HRTIMER_NORESTART;
655 static int sllin_rx_validate(struct sllin *sl)
660 unsigned char rec_chcksm = sl->rx_buff[sl->rx_cnt - 1];
661 struct sllin_conf_entry *scf;
663 actual_id = sl->rx_buff[SLLIN_BUFF_ID] & SLLIN_ID_MASK;
664 scf = &sl->linfr_cache[actual_id];
666 ext_chcks_fl = scf->frame_fl & SLLIN_CHECKSUM_EXTENDED;
668 if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1, ext_chcks_fl) !=
671 /* Type of checksum is configured for particular frame */
675 if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1,
676 !ext_chcks_fl) != rec_chcksm) {
685 /*****************************************
686 * sllin_kwthread - kernel worker thread
687 *****************************************/
689 int sllin_kwthread(void *ptr)
691 struct sllin *sl = (struct sllin *)ptr;
692 struct tty_struct *tty = sl->tty;
693 struct sched_param schparam = { .sched_priority = 40 };
694 int tx_bytes = 0; /* Used for Network statistics */
697 pr_debug("sllin: sllin_kwthread started.\n");
698 sched_setscheduler(current, SCHED_FIFO, &schparam);
700 clear_bit(SLF_ERROR, &sl->flags);
701 sltty_change_speed(tty, sl->lin_baud);
703 while (!kthread_should_stop()) {
704 struct can_frame *cf;
707 u8 lin_data_buff[SLLIN_DATA_MAX];
710 if ((sl->lin_state == SLSTATE_IDLE) && sl->lin_master &&
712 if(sllin_send_break(sl) < 0) {
713 /* error processing */
717 wait_event_killable(sl->kwt_wq, kthread_should_stop() ||
718 test_bit(SLF_RXEVENT, &sl->flags) ||
719 test_bit(SLF_TXEVENT, &sl->flags) ||
720 test_bit(SLF_TMOUTEVENT, &sl->flags) ||
721 (((sl->lin_state == SLSTATE_IDLE) ||
722 (sl->lin_state == SLSTATE_RESPONSE_WAIT))
723 && test_bit(SLF_MSGEVENT, &sl->flags)));
725 if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) {
726 pr_debug("sllin: sllin_kthread RXEVENT \n");
729 if (test_and_clear_bit(SLF_TXEVENT, &sl->flags)) {
730 pr_debug("sllin: sllin_kthread TXEVENT \n");
733 if (test_and_clear_bit(SLF_TMOUTEVENT, &sl->flags)) {
734 pr_debug("sllin: sllin_kthread TMOUTEVENT \n");
737 sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
740 sl->id_to_send = false;
741 sl->data_to_send = false;
743 sl->lin_state = SLSTATE_IDLE;
746 switch (sl->lin_state) {
748 if (!test_bit(SLF_MSGEVENT, &sl->flags))
751 cf = (struct can_frame *)sl->tx_req_skb->data;
753 /* SFF RTR CAN frame -> LIN header */
754 if (cf->can_id & CAN_RTR_FLAG) {
755 spin_lock(&sl->lock);
756 pr_debug("sllin: %s: RTR SFF CAN frame, ID = %x\n",
757 __FUNCTION__, cf->can_id & SLLIN_ID_MASK);
759 /* Is there Slave response in linfr_cache to be sent? */
760 if ((sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].frame_fl &
761 SLLIN_LOC_SLAVE_CACHE)
762 && (sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].dlc > 0)) {
764 pr_debug("sllin: Sending LIN response from linfr_cache\n");
765 lin_data = sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].data;
766 lin_dlc = sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].dlc;
767 if (lin_dlc > SLLIN_DATA_MAX)
768 lin_dlc = SLLIN_DATA_MAX;
769 memcpy(lin_data_buff, lin_data, lin_dlc);
770 lin_data = lin_data_buff;
773 lin_dlc = sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].dlc;
775 spin_unlock(&sl->lock);
776 } else { /* SFF NON-RTR CAN frame -> LIN header + LIN response */
777 pr_debug("sllin: %s: NON-RTR SFF CAN frame, ID = %x\n",
778 __FUNCTION__, (int)cf->can_id & SLLIN_ID_MASK);
781 lin_dlc = cf->can_dlc;
782 if (lin_dlc > SLLIN_DATA_MAX)
783 lin_dlc = SLLIN_DATA_MAX;
787 if (sllin_setup_msg(sl, 0, cf->can_id & SLLIN_ID_MASK,
788 lin_data, lin_dlc) != -1) {
790 sl->id_to_send = true;
791 sl->data_to_send = (lin_data != NULL) ? true : false;
792 sl->resp_len_known = (lin_dlc > 0) ? true : false;
793 sl->dev->stats.tx_packets++;
794 sl->dev->stats.tx_bytes += tx_bytes;
797 clear_bit(SLF_MSGEVENT, &sl->flags);
798 kfree_skb(sl->tx_req_skb);
799 netif_wake_queue(sl->dev);
802 case SLSTATE_BREAK_SENT:
804 if (sl->rx_cnt <= SLLIN_BUFF_BREAK)
807 res = sltty_change_speed(tty, sl->lin_baud);
810 sl->lin_state = SLSTATE_ID_SENT;
811 sllin_send_tx_buff(sl);
814 case SLSTATE_ID_SENT:
815 sl->id_to_send = false;
816 if (sl->data_to_send) {
817 sllin_send_tx_buff(sl);
818 sl->lin_state = SLSTATE_RESPONSE_SENT;
819 sl->rx_expect = sl->tx_lim;
820 goto slstate_response_sent;
822 if (sl->resp_len_known) {
823 sl->rx_expect = sl->rx_lim;
825 sl->rx_expect = SLLIN_BUFF_DATA + 2;
827 sl->lin_state = SLSTATE_RESPONSE_WAIT;
828 /* If we don't receive anything, timer will "unblock" us */
829 hrtimer_start(&sl->rx_timer,
830 ktime_add(ktime_get(), sl->rx_timer_timeout),
832 goto slstate_response_wait;
836 case SLSTATE_RESPONSE_WAIT:
837 slstate_response_wait:
838 if (test_bit(SLF_MSGEVENT, &sl->flags)) {
839 unsigned char *lin_buff;
840 cf = (struct can_frame *)sl->tx_req_skb->data;
842 lin_buff = (sl->lin_master) ? sl->tx_buff : sl->rx_buff;
843 if (cf->can_id == (lin_buff[SLLIN_BUFF_ID] & SLLIN_ID_MASK)) {
844 if (sllin_setup_msg(sl, SLLIN_STPMSG_RESPONLY,
845 cf->can_id & SLLIN_ID_MASK,
846 cf->data, cf->can_dlc) != -1) {
848 sl->rx_expect = sl->tx_lim;
849 sl->data_to_send = true;
850 sl->dev->stats.tx_packets++;
851 sl->dev->stats.tx_bytes += tx_bytes;
853 if (!sl->lin_master) {
854 sl->tx_cnt = SLLIN_BUFF_DATA;
857 sllin_send_tx_buff(sl);
858 clear_bit(SLF_MSGEVENT, &sl->flags);
859 kfree_skb(sl->tx_req_skb);
860 netif_wake_queue(sl->dev);
862 sl->lin_state = SLSTATE_RESPONSE_SENT;
863 goto slstate_response_sent;
866 sl->lin_state = SLSTATE_RESPONSE_WAIT_BUS;
870 case SLSTATE_RESPONSE_WAIT_BUS:
871 if (sl->rx_cnt < sl->rx_expect)
874 hrtimer_cancel(&sl->rx_timer);
875 pr_debug("sllin: response received ID %d len %d\n",
876 sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
878 if (sllin_rx_validate(sl) == -1) {
879 pr_debug("sllin: RX validation failed.\n");
880 sllin_report_error(sl, SLLIN_ERR_CHECKSUM);
881 //FIXME tx_stat.err++
883 // send CAN non-RTR frame with data
884 pr_debug("sllin: sending NON-RTR CAN"
885 "frame with LIN payload.");
886 sll_bump(sl); //send packet to the network layer
889 sl->id_to_send = false;
890 sl->lin_state = SLSTATE_IDLE;
893 case SLSTATE_RESPONSE_SENT:
894 slstate_response_sent:
895 if (sl->rx_cnt < sl->tx_lim)
898 sll_bump(sl); //send packet to the network layer
899 pr_debug("sllin: response sent ID %d len %d\n",
900 sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
902 sl->id_to_send = false;
903 sl->lin_state = SLSTATE_IDLE;
910 /* sl->dev->stats.tx_packets++; send frames statistic */
911 /* netif_wake_queue(sl->dev); allow next Tx packet arrival */
914 hrtimer_cancel(&sl->rx_timer);
915 pr_debug("sllin: sllin_kwthread stopped.\n");
921 /************************************
922 * sllin_open helper routines.
923 ************************************/
925 /* Collect hanged up channels */
926 static void sll_sync(void)
929 struct net_device *dev;
932 for (i = 0; i < maxdev; i++) {
937 sl = netdev_priv(dev);
940 if (dev->flags & IFF_UP)
945 /* Find a free SLLIN channel, and link in this `tty' line. */
946 static struct sllin *sll_alloc(dev_t line)
949 struct net_device *dev = NULL;
952 if (sllin_devs == NULL)
953 return NULL; /* Master array missing ! */
955 for (i = 0; i < maxdev; i++) {
962 /* Sorry, too many, all slots in use */
967 sl = netdev_priv(dev);
968 if (test_bit(SLF_INUSE, &sl->flags)) {
969 unregister_netdevice(dev);
971 sllin_devs[i] = NULL;
977 sprintf(name, "sllin%d", i);
979 dev = alloc_netdev(sizeof(*sl), name, sll_setup);
985 sl = netdev_priv(dev);
986 /* Initialize channel control data */
987 sl->magic = SLLIN_MAGIC;
989 spin_lock_init(&sl->lock);
996 * Open the high-level part of the SLLIN channel.
997 * This function is called by the TTY module when the
998 * SLLIN line discipline is called for. Because we are
999 * sure the tty line exists, we only have to link it to
1000 * a free SLLIN channel...
1002 * Called in process context serialized from other ldisc calls.
1005 static int sllin_open(struct tty_struct *tty)
1009 pr_debug("sllin: %s() invoked\n", __FUNCTION__);
1011 if (!capable(CAP_NET_ADMIN))
1014 if (tty->ops->write == NULL)
1017 /* RTnetlink lock is misused here to serialize concurrent
1018 opens of sllin channels. There are better ways, but it is
1023 /* Collect hanged up channels. */
1026 sl = tty->disc_data;
1029 /* First make sure we're not already connected. */
1030 if (sl && sl->magic == SLLIN_MAGIC)
1033 /* OK. Find a free SLLIN channel to use. */
1035 sl = sll_alloc(tty_devnum(tty));
1040 tty->disc_data = sl;
1041 sl->line = tty_devnum(tty);
1043 if (!test_bit(SLF_INUSE, &sl->flags)) {
1044 /* Perform the low-level SLLIN initialization. */
1045 sl->lin_master = true;
1049 sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
1052 sl->id_to_send = false;
1053 sl->data_to_send = false;
1055 sl->lin_baud = 19200;
1057 sl->lin_state = SLSTATE_IDLE;
1059 hrtimer_init(&sl->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1060 sl->rx_timer.function = sllin_rx_timeout_handler;
1061 /* timeval_to_ktime(msg_head->ival1); */
1062 sl->rx_timer_timeout = ns_to_ktime(
1063 (1000000000l / sl->lin_baud) *
1064 SLLIN_SAMPLES_PER_CHAR * SLLIN_CHARS_TO_TIMEOUT);
1066 set_bit(SLF_INUSE, &sl->flags);
1068 init_waitqueue_head(&sl->kwt_wq);
1069 sl->kwthread = kthread_run(sllin_kwthread, sl, "sllin");
1070 if (sl->kwthread == NULL)
1073 err = register_netdevice(sl->dev);
1075 goto err_free_chan_and_thread;
1078 /* Done. We have linked the TTY line to a channel. */
1080 tty->receive_room = SLLIN_BUFF_LEN * 40; /* We don't flow control */
1082 /* TTY layer expects 0 on success */
1085 err_free_chan_and_thread:
1086 kthread_stop(sl->kwthread);
1087 sl->kwthread = NULL;
1091 tty->disc_data = NULL;
1092 clear_bit(SLF_INUSE, &sl->flags);
1097 /* Count references from TTY module */
1102 * Close down a SLLIN channel.
1103 * This means flushing out any pending queues, and then returning. This
1104 * call is serialized against other ldisc functions.
1106 * We also use this method for a hangup event.
1109 static void sllin_close(struct tty_struct *tty)
1111 struct sllin *sl = (struct sllin *) tty->disc_data;
1113 /* First make sure we're connected. */
1114 if (!sl || sl->magic != SLLIN_MAGIC || sl->tty != tty)
1117 kthread_stop(sl->kwthread);
1118 sl->kwthread = NULL;
1120 tty->disc_data = NULL;
1123 /* Flush network side */
1124 unregister_netdev(sl->dev);
1125 /* This will complete via sl_free_netdev */
1128 static int sllin_hangup(struct tty_struct *tty)
1134 /* Perform I/O control on an active SLLIN channel. */
1135 static int sllin_ioctl(struct tty_struct *tty, struct file *file,
1136 unsigned int cmd, unsigned long arg)
1138 struct sllin *sl = (struct sllin *) tty->disc_data;
1141 /* First make sure we're connected. */
1142 if (!sl || sl->magic != SLLIN_MAGIC)
1147 tmp = strlen(sl->dev->name) + 1;
1148 if (copy_to_user((void __user *)arg, sl->dev->name, tmp))
1156 return tty_mode_ioctl(tty, file, cmd, arg);
1160 static struct tty_ldisc_ops sll_ldisc = {
1161 .owner = THIS_MODULE,
1162 .magic = TTY_LDISC_MAGIC,
1165 .close = sllin_close,
1166 .hangup = sllin_hangup,
1167 .ioctl = sllin_ioctl,
1168 .receive_buf = sllin_receive_buf,
1169 .write_wakeup = sllin_write_wakeup,
1172 static int __init sllin_init(void)
1177 maxdev = 4; /* Sanity */
1180 pr_debug("sllin: %d dynamic interface channels.\n", maxdev);
1182 sllin_devs = kzalloc(sizeof(struct net_device *)*maxdev, GFP_KERNEL);
1184 printk(KERN_ERR "sllin: can't allocate sllin device array!\n");
1188 /* Fill in our line protocol discipline, and register it */
1189 status = tty_register_ldisc(N_SLLIN, &sll_ldisc);
1191 printk(KERN_ERR "sllin: can't register line discipline\n");
1195 #ifdef BREAK_BY_BAUD
1196 pr_debug("sllin: Break is generated by baud-rate change.");
1198 pr_debug("sllin: Break is generated manually with tiny sleep.");
1204 static void __exit sllin_exit(void)
1207 struct net_device *dev;
1209 unsigned long timeout = jiffies + HZ;
1212 if (sllin_devs == NULL)
1215 /* First of all: check for active disciplines and hangup them.
1219 msleep_interruptible(100);
1222 for (i = 0; i < maxdev; i++) {
1223 dev = sllin_devs[i];
1226 sl = netdev_priv(dev);
1227 spin_lock_bh(&sl->lock);
1230 tty_hangup(sl->tty);
1232 spin_unlock_bh(&sl->lock);
1234 } while (busy && time_before(jiffies, timeout));
1236 /* FIXME: hangup is async so we should wait when doing this second
1239 for (i = 0; i < maxdev; i++) {
1240 dev = sllin_devs[i];
1243 sllin_devs[i] = NULL;
1245 sl = netdev_priv(dev);
1247 printk(KERN_ERR "%s: tty discipline still running\n",
1249 /* Intentionally leak the control block. */
1250 dev->destructor = NULL;
1253 unregister_netdev(dev);
1259 i = tty_unregister_ldisc(N_SLLIN);
1261 printk(KERN_ERR "sllin: can't unregister ldisc (err %d)\n", i);
1264 module_init(sllin_init);
1265 module_exit(sllin_exit);