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 * Idea: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
36 * Copyright: (c) 2011 Czech Technical University in Prague
37 * (c) 2011 Volkswagen Group Research
38 * Authors: Pavel Pisa <pisa@cmp.felk.cvut.cz>
39 * Rostislav Lisovy <lisovy@kormus.cz>
40 * Michal Sojka <sojkam1@fel.cvut.cz>
41 * Funded by: Volkswagen Group Research
44 #define DEBUG 1 /* Enables pr_debug() printouts */
46 #include <linux/module.h>
47 #include <linux/moduleparam.h>
49 #include <linux/uaccess.h>
50 #include <linux/bitops.h>
51 #include <linux/string.h>
52 #include <linux/tty.h>
53 #include <linux/errno.h>
54 #include <linux/netdevice.h>
55 #include <linux/skbuff.h>
56 #include <linux/rtnetlink.h>
57 #include <linux/if_arp.h>
58 #include <linux/if_ether.h>
59 #include <linux/sched.h>
60 #include <linux/delay.h>
61 #include <linux/init.h>
62 #include <linux/can.h>
63 #include <linux/kthread.h>
64 #include <linux/hrtimer.h>
65 #include <linux/version.h>
66 #include "linux/lin_bus.h"
68 /* Should be in include/linux/tty.h */
70 /* -------------------------------- */
72 static __initdata const char banner[] =
73 KERN_INFO "sllin: serial line LIN interface driver\n";
75 MODULE_ALIAS_LDISC(N_SLLIN);
76 MODULE_DESCRIPTION("serial line LIN interface");
77 MODULE_LICENSE("GPL");
78 MODULE_AUTHOR("Pavel Pisa <pisa@cmp.felk.cvut.cz>");
80 #define SLLIN_MAGIC 0x53CA
81 /* #define BREAK_BY_BAUD */
83 static bool master = true;
84 static int baudrate; /* Use LIN_DEFAULT_BAUDRATE when not set */
86 module_param(master, bool, 0);
87 MODULE_PARM_DESC(master, "LIN interface is Master device");
88 module_param(baudrate, int, 0);
89 MODULE_PARM_DESC(baudrate, "Baudrate of LIN interface");
91 static int maxdev = 10; /* MAX number of SLLIN channels;
92 This can be overridden with
93 insmod sllin.ko maxdev=nnn */
94 module_param(maxdev, int, 0);
95 MODULE_PARM_DESC(maxdev, "Maximum number of sllin interfaces");
97 /* maximum buffer len to store whole LIN message*/
98 #define SLLIN_DATA_MAX 8
99 #define SLLIN_BUFF_LEN (1 /*break*/ + 1 /*sync*/ + 1 /*ID*/ + \
100 SLLIN_DATA_MAX + 1 /*checksum*/)
101 #define SLLIN_BUFF_BREAK 0
102 #define SLLIN_BUFF_SYNC 1
103 #define SLLIN_BUFF_ID 2
104 #define SLLIN_BUFF_DATA 3
106 #define SLLIN_SAMPLES_PER_CHAR 10
107 #define SLLIN_CHARS_TO_TIMEOUT 24
113 SLSTATE_RESPONSE_WAIT, /* Wait for response */
114 SLSTATE_RESPONSE_WAIT_BUS, /* Wait for response from LIN bus
115 only (CAN frames from network stack
116 are not processed in this moment) */
118 SLSTATE_RESPONSE_SENT,
121 struct sllin_conf_entry {
122 int dlc; /* Length of data in LIN frame */
123 canid_t frame_fl; /* LIN frame flags. Passed from userspace as
125 u8 data[8]; /* LIN frame data payload */
131 /* Various fields. */
132 struct tty_struct *tty; /* ptr to TTY structure */
133 struct net_device *dev; /* easy for intr handling */
136 /* LIN message buffer and actual processed data counts */
137 unsigned char rx_buff[SLLIN_BUFF_LEN]; /* LIN Rx buffer */
138 unsigned char tx_buff[SLLIN_BUFF_LEN]; /* LIN Tx buffer */
139 int rx_expect; /* expected number of Rx chars */
140 int rx_lim; /* maximum Rx chars for current frame */
141 int rx_cnt; /* message buffer Rx fill level */
142 int tx_lim; /* actual limit of bytes to Tx */
143 int tx_cnt; /* number of already Tx bytes */
144 char lin_master; /* node is a master node */
145 int lin_baud; /* LIN baudrate */
146 int lin_state; /* state */
147 char id_to_send; /* there is ID to be sent */
148 char data_to_send; /* there are data to be sent */
149 char resp_len_known; /* Length of the response is known */
150 char header_received;/* In Slave mode, set when header was already
152 char rx_len_unknown; /* We are not sure how much data will be sent to us --
153 we just guess the length */
155 unsigned long flags; /* Flag values/ mode etc */
156 #define SLF_INUSE 0 /* Channel in use */
157 #define SLF_ERROR 1 /* Parity, etc. error */
158 #define SLF_RXEVENT 2 /* Rx wake event */
159 #define SLF_TXEVENT 3 /* Tx wake event */
160 #define SLF_MSGEVENT 4 /* CAN message to sent */
161 #define SLF_TMOUTEVENT 5 /* Timeout on received data */
162 #define SLF_TXBUFF_RQ 6 /* Req. to send buffer to UART*/
163 #define SLF_TXBUFF_INPR 7 /* Above request in progress */
166 struct task_struct *kwthread;
167 wait_queue_head_t kwt_wq; /* Wait queue used by kwthread */
168 struct hrtimer rx_timer; /* RX timeout timer */
169 ktime_t rx_timer_timeout; /* RX timeout timer value */
170 struct sk_buff *tx_req_skb; /* Socket buffer with CAN frame
171 received from network stack*/
173 /* List with configurations for each of 0 to LIN_ID_MAX LIN IDs */
174 struct sllin_conf_entry linfr_cache[LIN_ID_MAX + 1];
175 spinlock_t linfr_lock; /* frame cache and buffers lock */
178 static struct net_device **sllin_devs;
179 static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf);
180 static void sllin_slave_receive_buf(struct tty_struct *tty,
181 const unsigned char *cp, char *fp, int count);
182 static void sllin_master_receive_buf(struct tty_struct *tty,
183 const unsigned char *cp, char *fp, int count);
186 /* Values of two parity bits in LIN Protected
187 Identifier for each particular LIN ID */
188 const unsigned char sllin_id_parity_table[] = {
189 0x80, 0xc0, 0x40, 0x00, 0xc0, 0x80, 0x00, 0x40,
190 0x00, 0x40, 0xc0, 0x80, 0x40, 0x00, 0x80, 0xc0,
191 0x40, 0x00, 0x80, 0xc0, 0x00, 0x40, 0xc0, 0x80,
192 0xc0, 0x80, 0x00, 0x40, 0x80, 0xc0, 0x40, 0x00,
193 0x00, 0x40, 0xc0, 0x80, 0x40, 0x00, 0x80, 0xc0,
194 0x80, 0xc0, 0x40, 0x00, 0xc0, 0x80, 0x00, 0x40,
195 0xc0, 0x80, 0x00, 0x40, 0x80, 0xc0, 0x40, 0x00,
196 0x40, 0x00, 0x80, 0xc0, 0x00, 0x40, 0xc0, 0x80
200 * sltty_change_speed() -- Change baudrate of Serial device belonging
203 * @tty: Pointer to TTY to change speed for.
204 * @speed: Integer value of new speed. It is possible to
205 * assign non-standard values, i.e. those which
206 * are not defined in termbits.h.
208 static int sltty_change_speed(struct tty_struct *tty, unsigned speed)
210 struct ktermios old_termios, termios;
213 mutex_lock(&tty->termios_mutex);
215 #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 7, 0)
216 old_termios = termios = *(tty->termios);
218 old_termios = termios = tty->termios;
221 cflag = CS8 | CREAD | CLOCAL | HUPCL;
222 cflag &= ~(CBAUD | CIBAUD);
224 termios.c_cflag = cflag;
228 /* Enable interrupt when UART-Break or Framing error received */
229 termios.c_iflag = BRKINT | INPCK;
230 #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 7, 0)
231 *(tty->termios) = termios;
233 tty->termios = termios;
236 tty_encode_baud_rate(tty, speed, speed);
238 if (tty->ops->set_termios)
239 tty->ops->set_termios(tty, &old_termios);
241 mutex_unlock(&tty->termios_mutex);
246 /* Send one can_frame to the network layer */
247 static void sllin_send_canfr(struct sllin *sl, canid_t id, char *data, int len)
255 memcpy(&cf.data, data, cf.can_dlc);
257 skb = dev_alloc_skb(sizeof(struct can_frame));
262 skb->protocol = htons(ETH_P_CAN);
263 skb->pkt_type = PACKET_BROADCAST;
264 skb->ip_summed = CHECKSUM_UNNECESSARY;
265 memcpy(skb_put(skb, sizeof(struct can_frame)),
266 &cf, sizeof(struct can_frame));
269 sl->dev->stats.rx_packets++;
270 sl->dev->stats.rx_bytes += cf.can_dlc;
274 * sll_bump() -- Send data of received LIN frame (existing in sl->rx_buff)
279 static void sll_bump(struct sllin *sl)
281 int len = sl->rx_cnt - SLLIN_BUFF_DATA - 1; /* without checksum */
282 len = (len < 0) ? 0 : len;
284 sllin_send_canfr(sl, sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK,
285 sl->rx_buff + SLLIN_BUFF_DATA, len);
288 static void sll_send_rtr(struct sllin *sl)
290 sllin_send_canfr(sl, (sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK) |
291 CAN_RTR_FLAG, NULL, 0);
295 * Called by the driver when there's room for more data. If we have
296 * more packets to send, we send them here.
298 static void sllin_write_wakeup(struct tty_struct *tty)
302 struct sllin *sl = (struct sllin *) tty->disc_data;
304 /* First make sure we're connected. */
305 if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
308 set_bit(SLF_TXBUFF_RQ, &sl->flags);
310 if (unlikely(test_and_set_bit(SLF_TXBUFF_INPR, &sl->flags)))
311 return; /* ongoing concurrent processing */
313 clear_bit(SLF_TXBUFF_RQ, &sl->flags);
314 smp_mb__after_clear_bit();
316 if (sl->lin_state != SLSTATE_BREAK_SENT)
317 remains = sl->tx_lim - sl->tx_cnt;
319 remains = SLLIN_BUFF_BREAK + 1 - sl->tx_cnt;
322 actual = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt,
323 sl->tx_cnt - sl->tx_lim);
324 sl->tx_cnt += actual;
327 clear_bit(SLF_TXBUFF_INPR, &sl->flags);
328 smp_mb__after_clear_bit();
330 } while (unlikely(test_bit(SLF_TXBUFF_RQ, &sl->flags)));
332 if ((remains > 0) && (actual >= 0)) {
333 netdev_dbg(sl->dev, "sllin_write_wakeup sent %d, remains %d, waiting\n",
334 sl->tx_cnt, sl->tx_lim - sl->tx_cnt);
338 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
339 set_bit(SLF_TXEVENT, &sl->flags);
340 wake_up(&sl->kwt_wq);
342 netdev_dbg(sl->dev, "sllin_write_wakeup sent %d, wakeup\n", sl->tx_cnt);
346 * sll_xmit() -- Send a can_frame to a TTY queue.
348 * @skb: Pointer to Socket buffer to be sent.
349 * @dev: Network device where @skb will be sent.
351 static netdev_tx_t sll_xmit(struct sk_buff *skb, struct net_device *dev)
353 struct sllin *sl = netdev_priv(dev);
354 struct can_frame *cf;
356 if (skb->len != sizeof(struct can_frame))
359 spin_lock(&sl->lock);
360 if (!netif_running(dev)) {
361 netdev_warn(sl->dev, "xmit: iface is down\n");
364 if (sl->tty == NULL) {
365 netdev_warn(sl->dev, "xmit: no tty device connected\n");
369 cf = (struct can_frame *) skb->data;
370 if (cf->can_id & LIN_CTRL_FRAME) {
371 sllin_configure_frame_cache(sl, cf);
372 goto free_out_unlock;
375 netif_stop_queue(sl->dev);
377 sl->tx_req_skb = skb;
378 set_bit(SLF_MSGEVENT, &sl->flags);
379 wake_up(&sl->kwt_wq);
380 spin_unlock(&sl->lock);
385 spin_unlock(&sl->lock);
392 /******************************************
393 * Routines looking at netdevice side.
394 ******************************************/
396 /* Netdevice UP -> DOWN routine */
397 static int sll_close(struct net_device *dev)
399 struct sllin *sl = netdev_priv(dev);
401 spin_lock_bh(&sl->lock);
403 /* TTY discipline is running. */
404 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
406 netif_stop_queue(dev);
409 spin_unlock_bh(&sl->lock);
414 /* Netdevice DOWN -> UP routine */
415 static int sll_open(struct net_device *dev)
417 struct sllin *sl = netdev_priv(dev);
419 netdev_dbg(sl->dev, "%s() invoked\n", __func__);
424 sl->flags &= (1 << SLF_INUSE);
425 netif_start_queue(dev);
429 /* Hook the destructor so we can free sllin devs at the right point in time */
430 static void sll_free_netdev(struct net_device *dev)
432 int i = dev->base_addr;
434 sllin_devs[i] = NULL;
437 static const struct net_device_ops sll_netdev_ops = {
438 .ndo_open = sll_open,
439 .ndo_stop = sll_close,
440 .ndo_start_xmit = sll_xmit,
443 static void sll_setup(struct net_device *dev)
445 dev->netdev_ops = &sll_netdev_ops;
446 dev->destructor = sll_free_netdev;
448 dev->hard_header_len = 0;
450 dev->tx_queue_len = 10;
452 dev->mtu = sizeof(struct can_frame);
453 dev->type = ARPHRD_CAN;
455 /* New-style flags. */
456 dev->flags = IFF_NOARP;
457 dev->features = NETIF_F_HW_CSUM; /* NETIF_F_NO_CSUM;*/
460 /******************************************
461 Routines looking at TTY side.
462 ******************************************/
463 static void sllin_master_receive_buf(struct tty_struct *tty,
464 const unsigned char *cp, char *fp, int count)
466 struct sllin *sl = (struct sllin *) tty->disc_data;
468 /* Read the characters out of the buffer */
471 netdev_dbg(sl->dev, "sllin_master_receive_buf char 0x%02x ignored "
472 "due marker 0x%02x, flags 0x%lx\n",
473 *cp, *(fp-1), sl->flags);
475 /* i.e. Real error -- not Break */
476 if (sl->rx_cnt > SLLIN_BUFF_BREAK) {
477 set_bit(SLF_ERROR, &sl->flags);
478 wake_up(&sl->kwt_wq);
483 #ifndef BREAK_BY_BAUD
484 /* We didn't receive Break character -- fake it! */
485 if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
486 netdev_dbg(sl->dev, "LIN_RX[%d]: 0x00\n", sl->rx_cnt);
487 sl->rx_buff[sl->rx_cnt++] = 0x00;
489 #endif /* BREAK_BY_BAUD */
491 if (sl->rx_cnt < SLLIN_BUFF_LEN) {
492 netdev_dbg(sl->dev, "LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
493 sl->rx_buff[sl->rx_cnt++] = *cp++;
498 if (sl->rx_cnt >= sl->rx_expect) {
499 set_bit(SLF_RXEVENT, &sl->flags);
500 wake_up(&sl->kwt_wq);
501 netdev_dbg(sl->dev, "sllin_receive_buf count %d, wakeup\n", sl->rx_cnt);
503 netdev_dbg(sl->dev, "sllin_receive_buf count %d, waiting\n", sl->rx_cnt);
508 /*****************************************
509 * sllin message helper routines
510 *****************************************/
512 * sllin_report_error() -- Report an error by sending CAN frame
513 * with particular error flag set in can_id
516 * @err: Error flag to be sent.
518 static void sllin_report_error(struct sllin *sl, int err)
520 unsigned char *lin_buff;
524 case LIN_ERR_CHECKSUM:
525 sl->dev->stats.rx_crc_errors++;
528 case LIN_ERR_RX_TIMEOUT:
529 sl->dev->stats.rx_errors++;
532 case LIN_ERR_FRAMING:
533 sl->dev->stats.rx_frame_errors++;
537 lin_buff = (sl->lin_master) ? sl->tx_buff : sl->rx_buff;
538 lin_id = lin_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
539 sllin_send_canfr(sl, lin_id | CAN_EFF_FLAG |
540 (err & ~LIN_ID_MASK), NULL, 0);
544 * sllin_configure_frame_cache() -- Configure particular entry in linfr_cache
547 * @cf: Pointer to CAN frame sent to this driver
548 * holding configuration information
550 static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf)
553 struct sllin_conf_entry *sce;
555 if (!(cf->can_id & LIN_CTRL_FRAME))
558 sce = &sl->linfr_cache[cf->can_id & LIN_ID_MASK];
559 netdev_dbg(sl->dev, "Setting frame cache with EFF CAN frame. LIN ID = %d\n",
560 cf->can_id & LIN_ID_MASK);
562 spin_lock_irqsave(&sl->linfr_lock, flags);
564 sce->dlc = cf->can_dlc;
565 if (sce->dlc > SLLIN_DATA_MAX)
566 sce->dlc = SLLIN_DATA_MAX;
568 sce->frame_fl = (cf->can_id & ~LIN_ID_MASK) & CAN_EFF_MASK;
569 memcpy(sce->data, cf->data, cf->can_dlc);
571 spin_unlock_irqrestore(&sl->linfr_lock, flags);
577 * sllin_checksum() -- Count checksum for particular data
579 * @data: Pointer to the buffer containing whole LIN
580 * frame (i.e. including break and sync bytes).
581 * @length: Length of the buffer.
582 * @enhanced_fl: Flag determining whether Enhanced or Classic
583 * checksum should be counted.
585 static inline unsigned sllin_checksum(unsigned char *data, int length, int enhanced_fl)
595 for (; i < length; i++) {
604 #define SLLIN_STPMSG_RESPONLY (1) /* Message will be LIN Response only */
605 #define SLLIN_STPMSG_CHCKSUM_CLS (1 << 1)
606 #define SLLIN_STPMSG_CHCKSUM_ENH (1 << 2)
608 static int sllin_setup_msg(struct sllin *sl, int mode, int id,
609 unsigned char *data, int len)
611 if (id > LIN_ID_MASK)
614 if (!(mode & SLLIN_STPMSG_RESPONLY)) {
618 sl->rx_lim = SLLIN_BUFF_LEN;
621 sl->tx_buff[SLLIN_BUFF_BREAK] = 0;
622 sl->tx_buff[SLLIN_BUFF_SYNC] = 0x55;
623 sl->tx_buff[SLLIN_BUFF_ID] = id | sllin_id_parity_table[id];
624 sl->tx_lim = SLLIN_BUFF_DATA;
626 if ((data != NULL) && len) {
628 memcpy(sl->tx_buff + SLLIN_BUFF_DATA, data, len);
629 sl->tx_buff[sl->tx_lim] = sllin_checksum(sl->tx_buff,
630 sl->tx_lim, mode & SLLIN_STPMSG_CHCKSUM_ENH);
634 sl->rx_lim = SLLIN_BUFF_DATA + len + 1;
639 static void sllin_reset_buffs(struct sllin *sl)
643 sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
646 sl->id_to_send = false;
647 sl->data_to_send = false;
651 * sllin_rx_validate() -- Validate received frame, i,e. check checksum
655 static int sllin_rx_validate(struct sllin *sl)
661 unsigned char rec_chcksm = sl->rx_buff[sl->rx_cnt - 1];
662 struct sllin_conf_entry *sce;
664 actual_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
665 sce = &sl->linfr_cache[actual_id];
667 spin_lock_irqsave(&sl->linfr_lock, flags);
669 ext_chcks_fl = sce->frame_fl & LIN_CHECKSUM_EXTENDED;
670 spin_unlock_irqrestore(&sl->linfr_lock, flags);
672 if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1, ext_chcks_fl) !=
675 /* Type of checksum is configured for particular frame */
679 if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1,
680 !ext_chcks_fl) != rec_chcksm) {
689 static void sllin_slave_finish_rx_msg(struct sllin *sl)
691 if (sllin_rx_validate(sl) == -1) {
692 netdev_dbg(sl->dev, "sllin: RX validation failed.\n");
693 sllin_report_error(sl, LIN_ERR_CHECKSUM);
695 /* Send CAN non-RTR frame with data */
696 netdev_dbg(sl->dev, "sllin: sending NON-RTR CAN frame with LIN payload.");
697 sll_bump(sl); /* send packet to the network layer */
699 /* Prepare for reception of new header */
701 sl->rx_expect = SLLIN_BUFF_ID + 1;
702 sl->rx_len_unknown = false; /* We do know exact length of the header */
703 sl->header_received = false;
706 static void sllin_slave_receive_buf(struct tty_struct *tty,
707 const unsigned char *cp, char *fp, int count)
709 struct sllin *sl = (struct sllin *) tty->disc_data;
711 struct sllin_conf_entry *sce;
714 /* Read the characters out of the buffer */
718 * If we don't know the length of the current message
719 * we received the break of the next message.
720 * Evaluate the previous one before continuing
722 if (sl->rx_len_unknown == true)
724 hrtimer_cancel(&sl->rx_timer);
725 sllin_slave_finish_rx_msg(sl);
727 set_bit(SLF_RXEVENT, &sl->flags);
728 wake_up(&sl->kwt_wq);
731 netdev_dbg(sl->dev, "sllin_slave_receive_buf char 0x%02x ignored "
732 "due marker 0x%02x, flags 0x%lx\n",
733 *cp, *(fp-1), sl->flags);
737 sl->rx_expect = SLLIN_BUFF_ID + 1;
738 sl->rx_len_unknown = false; /* We do know exact length of the header */
739 sl->header_received = false;
742 if (sl->rx_cnt < SLLIN_BUFF_LEN) {
743 netdev_dbg(sl->dev, "LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
745 /* We did not receive break (0x00) character */
746 if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
747 sl->rx_buff[sl->rx_cnt++] = 0x00;
750 if (sl->rx_cnt == SLLIN_BUFF_SYNC) {
751 /* 'Duplicated' break character -- ignore */
757 /* Wrong sync character */
762 sl->rx_buff[sl->rx_cnt++] = *cp++;
765 /* Header received */
766 if ((sl->header_received == false) && (sl->rx_cnt >= (SLLIN_BUFF_ID + 1))) {
769 lin_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
770 sce = &sl->linfr_cache[lin_id];
772 spin_lock_irqsave(&sl->linfr_lock, flags);
774 sl->lin_state = SLSTATE_ID_RECEIVED;
775 /* Is the length of data set in frame cache? */
777 sl->rx_expect += sce->dlc + 1; /* + checksum */
778 sl->rx_len_unknown = false;
779 wake_up(&sl->kwt_wq);
781 sl->rx_expect += SLLIN_DATA_MAX + 1; /* + checksum */
782 sl->rx_len_unknown = true;
784 spin_unlock_irqrestore(&sl->linfr_lock, flags);
786 sl->header_received = true;
788 hrtimer_start(&sl->rx_timer,
789 ktime_add(ktime_get(), sl->rx_timer_timeout),
795 /* Response received */
796 if ((sl->header_received == true) &&
797 ((sl->rx_cnt >= sl->rx_expect))) {
799 hrtimer_cancel(&sl->rx_timer);
800 netdev_dbg(sl->dev, "Received LIN header & LIN response. "
801 "rx_cnt = %u, rx_expect = %u\n", sl->rx_cnt,
803 sllin_slave_finish_rx_msg(sl);
805 set_bit(SLF_RXEVENT, &sl->flags);
806 wake_up(&sl->kwt_wq);
811 static void sllin_receive_buf(struct tty_struct *tty,
812 const unsigned char *cp, char *fp, int count)
814 struct sllin *sl = (struct sllin *) tty->disc_data;
815 netdev_dbg(sl->dev, "sllin_receive_buf invoked, count = %u\n", count);
817 if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
821 sllin_master_receive_buf(tty, cp, fp, count);
823 sllin_slave_receive_buf(tty, cp, fp, count);
827 static int sllin_send_tx_buff(struct sllin *sl)
829 struct tty_struct *tty = sl->tty;
833 set_bit(SLF_TXBUFF_RQ, &sl->flags);
835 if (unlikely(test_and_set_bit(SLF_TXBUFF_INPR, &sl->flags)))
836 return 0; /* ongoing concurrent processing */
838 clear_bit(SLF_TXBUFF_RQ, &sl->flags);
839 smp_mb__after_clear_bit();
842 if (sl->lin_state != SLSTATE_BREAK_SENT)
843 remains = sl->tx_lim - sl->tx_cnt;
847 remains = sl->tx_lim - sl->tx_cnt;
850 res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains);
858 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
859 res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains);
861 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
869 netdev_dbg(sl->dev, "sllin_send_tx_buff sent %d, remains %d\n",
870 sl->tx_cnt, remains);
872 clear_bit(SLF_TXBUFF_INPR, &sl->flags);
873 smp_mb__after_clear_bit();
875 } while (unlikely(test_bit(SLF_TXBUFF_RQ, &sl->flags)));
880 clear_bit(SLF_TXBUFF_INPR, &sl->flags);
886 static int sllin_send_break(struct sllin *sl)
888 struct tty_struct *tty = sl->tty;
889 unsigned long break_baud;
892 break_baud = ((sl->lin_baud * 2) / 3);
893 sltty_change_speed(tty, break_baud);
895 tty->ops->flush_buffer(tty);
896 sl->rx_cnt = SLLIN_BUFF_BREAK;
898 sl->rx_expect = SLLIN_BUFF_BREAK + 1;
899 sl->lin_state = SLSTATE_BREAK_SENT;
901 res = sllin_send_tx_buff(sl);
903 sl->lin_state = SLSTATE_IDLE;
909 #else /* BREAK_BY_BAUD */
911 static int sllin_send_break(struct sllin *sl)
913 struct tty_struct *tty = sl->tty;
915 unsigned long break_baud;
916 unsigned long usleep_range_min;
917 unsigned long usleep_range_max;
919 break_baud = ((sl->lin_baud * 2) / 3);
920 sl->rx_cnt = SLLIN_BUFF_BREAK;
921 sl->rx_expect = SLLIN_BUFF_BREAK + 1;
922 sl->lin_state = SLSTATE_BREAK_SENT;
924 /* Do the break ourselves; Inspired by
925 http://lxr.linux.no/#linux+v3.1.2/drivers/tty/tty_io.c#L2452 */
926 retval = tty->ops->break_ctl(tty, -1);
931 usleep_range_min = (1000000l * SLLIN_SAMPLES_PER_CHAR) / break_baud;
932 usleep_range_max = usleep_range_min + 50;
933 usleep_range(usleep_range_min, usleep_range_max);
935 retval = tty->ops->break_ctl(tty, 0);
936 usleep_range_min = (1000000l * 1 /* 1 bit */) / break_baud;
937 usleep_range_max = usleep_range_min + 30;
938 usleep_range(usleep_range_min, usleep_range_max);
940 tty->ops->flush_buffer(tty);
942 sl->tx_cnt = SLLIN_BUFF_SYNC;
944 netdev_dbg(sl->dev, "Break sent.\n");
945 set_bit(SLF_RXEVENT, &sl->flags);
946 wake_up(&sl->kwt_wq);
950 #endif /* BREAK_BY_BAUD */
953 static enum hrtimer_restart sllin_rx_timeout_handler(struct hrtimer *hrtimer)
955 struct sllin *sl = container_of(hrtimer, struct sllin, rx_timer);
958 * Signal timeout when:
959 * master: We did not receive as much characters as expected
960 * slave: * we did not receive any data bytes at all
961 * * we know the length and didn't receive enough
963 if ((sl->lin_master) ||
964 (sl->rx_cnt <= SLLIN_BUFF_DATA) ||
965 ((!sl->rx_len_unknown) &&
966 (sl->rx_cnt < sl->rx_expect))) {
967 sllin_report_error(sl, LIN_ERR_RX_TIMEOUT);
968 set_bit(SLF_TMOUTEVENT, &sl->flags);
970 sllin_slave_finish_rx_msg(sl);
971 set_bit(SLF_RXEVENT, &sl->flags);
973 wake_up(&sl->kwt_wq);
975 return HRTIMER_NORESTART;
978 /*****************************************
979 * sllin_kwthread - kernel worker thread
980 *****************************************/
982 static int sllin_kwthread(void *ptr)
984 struct sllin *sl = (struct sllin *)ptr;
985 struct tty_struct *tty = sl->tty;
986 struct sched_param schparam = { .sched_priority = 40 };
987 int tx_bytes = 0; /* Used for Network statistics */
990 struct sllin_conf_entry *sce;
992 netdev_dbg(sl->dev, "sllin_kwthread started.\n");
993 sched_setscheduler(current, SCHED_FIFO, &schparam);
995 clear_bit(SLF_ERROR, &sl->flags);
996 sltty_change_speed(tty, sl->lin_baud);
998 while (!kthread_should_stop()) {
999 struct can_frame *cf;
1002 u8 lin_data_buff[SLLIN_DATA_MAX];
1005 if ((sl->lin_state == SLSTATE_IDLE) && sl->lin_master &&
1007 if (sllin_send_break(sl) < 0) {
1008 /* error processing */
1012 wait_event_killable(sl->kwt_wq, kthread_should_stop() ||
1013 test_bit(SLF_RXEVENT, &sl->flags) ||
1014 test_bit(SLF_TXEVENT, &sl->flags) ||
1015 test_bit(SLF_TMOUTEVENT, &sl->flags) ||
1016 test_bit(SLF_ERROR, &sl->flags) ||
1017 (sl->lin_state == SLSTATE_ID_RECEIVED) ||
1018 (((sl->lin_state == SLSTATE_IDLE) ||
1019 (sl->lin_state == SLSTATE_RESPONSE_WAIT))
1020 && test_bit(SLF_MSGEVENT, &sl->flags)));
1022 if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) {
1023 netdev_dbg(sl->dev, "sllin_kthread RXEVENT\n");
1026 if (test_and_clear_bit(SLF_ERROR, &sl->flags)) {
1027 unsigned long usleep_range_min;
1028 unsigned long usleep_range_max;
1029 hrtimer_cancel(&sl->rx_timer);
1030 netdev_dbg(sl->dev, "sllin_kthread ERROR\n");
1032 if (sl->lin_state != SLSTATE_IDLE)
1033 sllin_report_error(sl, LIN_ERR_FRAMING);
1035 usleep_range_min = (1000000l * SLLIN_SAMPLES_PER_CHAR * 10) /
1037 usleep_range_max = usleep_range_min + 50;
1038 usleep_range(usleep_range_min, usleep_range_max);
1039 sllin_reset_buffs(sl);
1040 sl->lin_state = SLSTATE_IDLE;
1043 if (test_and_clear_bit(SLF_TXEVENT, &sl->flags)) {
1044 netdev_dbg(sl->dev, "sllin_kthread TXEVENT\n");
1047 if (test_and_clear_bit(SLF_TMOUTEVENT, &sl->flags)) {
1048 netdev_dbg(sl->dev, "sllin_kthread TMOUTEVENT\n");
1049 sllin_reset_buffs(sl);
1051 sl->lin_state = SLSTATE_IDLE;
1054 switch (sl->lin_state) {
1056 if (!test_bit(SLF_MSGEVENT, &sl->flags))
1059 cf = (struct can_frame *)sl->tx_req_skb->data;
1061 /* SFF RTR CAN frame -> LIN header */
1062 if (cf->can_id & CAN_RTR_FLAG) {
1063 struct sllin_conf_entry *sce;
1065 netdev_dbg(sl->dev, "%s: RTR SFF CAN frame, ID = %x\n",
1066 __func__, cf->can_id & LIN_ID_MASK);
1068 sce = &sl->linfr_cache[cf->can_id & LIN_ID_MASK];
1069 spin_lock_irqsave(&sl->linfr_lock, flags);
1071 /* Is there Slave response in linfr_cache to be sent? */
1072 if ((sce->frame_fl & LIN_CACHE_RESPONSE)
1073 && (sce->dlc > 0)) {
1075 netdev_dbg(sl->dev, "Sending LIN response from linfr_cache\n");
1077 lin_data = sce->data;
1079 if (lin_dlc > SLLIN_DATA_MAX)
1080 lin_dlc = SLLIN_DATA_MAX;
1081 memcpy(lin_data_buff, lin_data, lin_dlc);
1082 lin_data = lin_data_buff;
1087 spin_unlock_irqrestore(&sl->linfr_lock, flags);
1089 } else { /* SFF NON-RTR CAN frame -> LIN header + LIN response */
1090 netdev_dbg(sl->dev, "%s: NON-RTR SFF CAN frame, ID = %x\n",
1091 __func__, (int)cf->can_id & LIN_ID_MASK);
1093 lin_data = cf->data;
1094 lin_dlc = cf->can_dlc;
1095 if (lin_dlc > SLLIN_DATA_MAX)
1096 lin_dlc = SLLIN_DATA_MAX;
1100 if (sllin_setup_msg(sl, 0, cf->can_id & LIN_ID_MASK,
1101 lin_data, lin_dlc) != -1) {
1103 sl->id_to_send = true;
1104 sl->data_to_send = (lin_data != NULL) ? true : false;
1105 sl->resp_len_known = (lin_dlc > 0) ? true : false;
1106 sl->dev->stats.tx_packets++;
1107 sl->dev->stats.tx_bytes += tx_bytes;
1110 clear_bit(SLF_MSGEVENT, &sl->flags);
1111 kfree_skb(sl->tx_req_skb);
1112 netif_wake_queue(sl->dev);
1113 hrtimer_start(&sl->rx_timer,
1114 ktime_add(ktime_get(), sl->rx_timer_timeout),
1118 case SLSTATE_BREAK_SENT:
1119 #ifdef BREAK_BY_BAUD
1120 if (sl->rx_cnt <= SLLIN_BUFF_BREAK)
1123 res = sltty_change_speed(tty, sl->lin_baud);
1126 sl->lin_state = SLSTATE_ID_SENT;
1127 sllin_send_tx_buff(sl);
1130 case SLSTATE_ID_SENT:
1131 hrtimer_cancel(&sl->rx_timer);
1132 sl->id_to_send = false;
1133 if (sl->data_to_send) {
1134 sllin_send_tx_buff(sl);
1135 sl->lin_state = SLSTATE_RESPONSE_SENT;
1136 sl->rx_expect = sl->tx_lim;
1137 goto slstate_response_sent;
1139 if (sl->resp_len_known) {
1140 sl->rx_expect = sl->rx_lim;
1142 sl->rx_expect = SLLIN_BUFF_DATA + 2;
1144 sl->lin_state = SLSTATE_RESPONSE_WAIT;
1145 /* If we don't receive anything, timer will "unblock" us */
1146 hrtimer_start(&sl->rx_timer,
1147 ktime_add(ktime_get(), sl->rx_timer_timeout),
1149 goto slstate_response_wait;
1153 case SLSTATE_RESPONSE_WAIT:
1154 slstate_response_wait:
1155 if (test_bit(SLF_MSGEVENT, &sl->flags)) {
1156 unsigned char *lin_buff;
1157 cf = (struct can_frame *)sl->tx_req_skb->data;
1159 lin_buff = (sl->lin_master) ? sl->tx_buff : sl->rx_buff;
1160 if (cf->can_id == (lin_buff[SLLIN_BUFF_ID] & LIN_ID_MASK)) {
1161 hrtimer_cancel(&sl->rx_timer);
1162 netdev_dbg(sl->dev, "received LIN response in a CAN frame.\n");
1163 if (sllin_setup_msg(sl, SLLIN_STPMSG_RESPONLY,
1164 cf->can_id & LIN_ID_MASK,
1165 cf->data, cf->can_dlc) != -1) {
1167 sl->rx_expect = sl->tx_lim;
1168 sl->data_to_send = true;
1169 sl->dev->stats.tx_packets++;
1170 sl->dev->stats.tx_bytes += tx_bytes;
1172 if (!sl->lin_master) {
1173 sl->tx_cnt = SLLIN_BUFF_DATA;
1176 sllin_send_tx_buff(sl);
1177 clear_bit(SLF_MSGEVENT, &sl->flags);
1178 kfree_skb(sl->tx_req_skb);
1179 netif_wake_queue(sl->dev);
1181 sl->lin_state = SLSTATE_RESPONSE_SENT;
1182 goto slstate_response_sent;
1185 sl->lin_state = SLSTATE_RESPONSE_WAIT_BUS;
1189 /* Be aware, no BREAK here */
1190 case SLSTATE_RESPONSE_WAIT_BUS:
1191 if (sl->rx_cnt < sl->rx_expect)
1194 hrtimer_cancel(&sl->rx_timer);
1195 netdev_dbg(sl->dev, "response received ID %d len %d\n",
1196 sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
1198 if (sllin_rx_validate(sl) == -1) {
1199 netdev_dbg(sl->dev, "RX validation failed.\n");
1200 sllin_report_error(sl, LIN_ERR_CHECKSUM);
1202 /* Send CAN non-RTR frame with data */
1203 netdev_dbg(sl->dev, "sending NON-RTR CAN frame with LIN payload.");
1204 sll_bump(sl); /* send packet to the network layer */
1207 sl->id_to_send = false;
1208 sl->lin_state = SLSTATE_IDLE;
1211 case SLSTATE_ID_RECEIVED:
1212 lin_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
1213 sce = &sl->linfr_cache[lin_id];
1214 spin_lock_irqsave(&sl->linfr_lock, flags);
1216 if ((sce->frame_fl & LIN_CACHE_RESPONSE)
1217 && (sce->dlc > 0)) {
1220 netdev_dbg(sl->dev, "Sending LIN response from linfr_cache\n");
1222 lin_data = sce->data;
1224 if (lin_dlc > SLLIN_DATA_MAX)
1225 lin_dlc = SLLIN_DATA_MAX;
1226 memcpy(lin_data_buff, lin_data, lin_dlc);
1227 lin_data = lin_data_buff;
1230 mode = SLLIN_STPMSG_RESPONLY;
1231 if (sce->frame_fl & LIN_CHECKSUM_EXTENDED)
1232 mode |= SLLIN_STPMSG_CHCKSUM_ENH;
1234 if (sllin_setup_msg(sl, mode, lin_id & LIN_ID_MASK,
1235 lin_data, lin_dlc) != -1) {
1237 sl->rx_expect = sl->tx_lim;
1238 sl->data_to_send = true;
1239 sl->dev->stats.tx_packets++;
1240 sl->dev->stats.tx_bytes += tx_bytes;
1241 sl->resp_len_known = true;
1243 if (!sl->lin_master) {
1244 sl->tx_cnt = SLLIN_BUFF_DATA;
1246 sllin_send_tx_buff(sl);
1249 hrtimer_start(&sl->rx_timer,
1250 ktime_add(ktime_get(), sl->rx_timer_timeout),
1253 spin_unlock_irqrestore(&sl->linfr_lock, flags);
1254 sl->lin_state = SLSTATE_IDLE;
1257 case SLSTATE_RESPONSE_SENT:
1258 slstate_response_sent:
1259 if (sl->rx_cnt < sl->tx_lim)
1262 hrtimer_cancel(&sl->rx_timer);
1263 sll_bump(sl); /* send packet to the network layer */
1264 netdev_dbg(sl->dev, "response sent ID %d len %d\n",
1265 sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
1267 sl->id_to_send = false;
1268 sl->lin_state = SLSTATE_IDLE;
1273 hrtimer_cancel(&sl->rx_timer);
1274 netdev_dbg(sl->dev, "sllin_kwthread stopped.\n");
1280 /************************************
1281 * sllin_open helper routines.
1282 ************************************/
1284 /* Collect hanged up channels */
1285 static void sll_sync(void)
1288 struct net_device *dev;
1291 for (i = 0; i < maxdev; i++) {
1292 dev = sllin_devs[i];
1296 sl = netdev_priv(dev);
1299 if (dev->flags & IFF_UP)
1304 /* Find a free SLLIN channel, and link in this `tty' line. */
1305 static struct sllin *sll_alloc(dev_t line)
1308 struct net_device *dev = NULL;
1311 if (sllin_devs == NULL)
1312 return NULL; /* Master array missing ! */
1314 for (i = 0; i < maxdev; i++) {
1315 dev = sllin_devs[i];
1321 /* Sorry, too many, all slots in use */
1326 sl = netdev_priv(dev);
1327 if (test_bit(SLF_INUSE, &sl->flags)) {
1328 unregister_netdevice(dev);
1330 sllin_devs[i] = NULL;
1335 char name[IFNAMSIZ];
1336 sprintf(name, "sllin%d", i);
1338 dev = alloc_netdev(sizeof(*sl), name, sll_setup);
1344 sl = netdev_priv(dev);
1345 /* Initialize channel control data */
1346 sl->magic = SLLIN_MAGIC;
1348 spin_lock_init(&sl->lock);
1349 spin_lock_init(&sl->linfr_lock);
1350 sllin_devs[i] = dev;
1356 * Open the high-level part of the SLLIN channel.
1357 * This function is called by the TTY module when the
1358 * SLLIN line discipline is called for. Because we are
1359 * sure the tty line exists, we only have to link it to
1360 * a free SLLIN channel...
1362 * Called in process context serialized from other ldisc calls.
1365 static int sllin_open(struct tty_struct *tty)
1370 pr_debug("sllin: %s() invoked\n", __func__);
1372 if (!capable(CAP_NET_ADMIN))
1375 if (tty->ops->write == NULL)
1378 /* RTnetlink lock is misused here to serialize concurrent
1379 opens of sllin channels. There are better ways, but it is
1384 /* Collect hanged up channels. */
1387 sl = tty->disc_data;
1390 /* First make sure we're not already connected. */
1391 if (sl && sl->magic == SLLIN_MAGIC)
1394 /* OK. Find a free SLLIN channel to use. */
1396 sl = sll_alloc(tty_devnum(tty));
1401 tty->disc_data = sl;
1402 sl->line = tty_devnum(tty);
1404 if (!test_bit(SLF_INUSE, &sl->flags)) {
1405 /* Perform the low-level SLLIN initialization. */
1406 sl->lin_master = master;
1408 pr_debug("sllin: Configured as MASTER\n");
1410 pr_debug("sllin: Configured as SLAVE\n");
1412 sllin_reset_buffs(sl);
1414 sl->lin_baud = (baudrate == 0) ? LIN_DEFAULT_BAUDRATE : baudrate;
1415 pr_debug("sllin: Baudrate set to %u\n", sl->lin_baud);
1417 sl->lin_state = SLSTATE_IDLE;
1419 hrtimer_init(&sl->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1420 sl->rx_timer.function = sllin_rx_timeout_handler;
1421 /* timeval_to_ktime(msg_head->ival1); */
1422 sl->rx_timer_timeout = ns_to_ktime(
1423 (1000000000l / sl->lin_baud) *
1424 SLLIN_SAMPLES_PER_CHAR * SLLIN_CHARS_TO_TIMEOUT);
1426 set_bit(SLF_INUSE, &sl->flags);
1428 init_waitqueue_head(&sl->kwt_wq);
1429 sl->kwthread = kthread_run(sllin_kwthread, sl, "sllin");
1430 if (sl->kwthread == NULL)
1433 err = register_netdevice(sl->dev);
1435 goto err_free_chan_and_thread;
1438 /* Done. We have linked the TTY line to a channel. */
1440 tty->receive_room = SLLIN_BUFF_LEN * 40; /* We don't flow control */
1442 /* TTY layer expects 0 on success */
1445 err_free_chan_and_thread:
1446 kthread_stop(sl->kwthread);
1447 sl->kwthread = NULL;
1451 tty->disc_data = NULL;
1452 clear_bit(SLF_INUSE, &sl->flags);
1457 /* Count references from TTY module */
1462 * Close down a SLLIN channel.
1463 * This means flushing out any pending queues, and then returning. This
1464 * call is serialized against other ldisc functions.
1466 * We also use this method for a hangup event.
1469 static void sllin_close(struct tty_struct *tty)
1471 struct sllin *sl = (struct sllin *) tty->disc_data;
1473 /* First make sure we're connected. */
1474 if (!sl || sl->magic != SLLIN_MAGIC || sl->tty != tty)
1477 kthread_stop(sl->kwthread);
1478 sl->kwthread = NULL;
1480 tty->disc_data = NULL;
1483 /* Flush network side */
1484 unregister_netdev(sl->dev);
1485 /* This will complete via sl_free_netdev */
1488 static int sllin_hangup(struct tty_struct *tty)
1494 /* Perform I/O control on an active SLLIN channel. */
1495 static int sllin_ioctl(struct tty_struct *tty, struct file *file,
1496 unsigned int cmd, unsigned long arg)
1498 struct sllin *sl = (struct sllin *) tty->disc_data;
1501 /* First make sure we're connected. */
1502 if (!sl || sl->magic != SLLIN_MAGIC)
1507 tmp = strlen(sl->dev->name) + 1;
1508 if (copy_to_user((void __user *)arg, sl->dev->name, tmp))
1516 return tty_mode_ioctl(tty, file, cmd, arg);
1520 static struct tty_ldisc_ops sll_ldisc = {
1521 .owner = THIS_MODULE,
1522 .magic = TTY_LDISC_MAGIC,
1525 .close = sllin_close,
1526 .hangup = sllin_hangup,
1527 .ioctl = sllin_ioctl,
1528 .receive_buf = sllin_receive_buf,
1529 .write_wakeup = sllin_write_wakeup,
1532 static int __init sllin_init(void)
1537 maxdev = 4; /* Sanity */
1540 pr_debug("sllin: %d dynamic interface channels.\n", maxdev);
1542 sllin_devs = kzalloc(sizeof(struct net_device *)*maxdev, GFP_KERNEL);
1544 pr_err("sllin: can't allocate sllin device array!\n");
1548 /* Fill in our line protocol discipline, and register it */
1549 status = tty_register_ldisc(N_SLLIN, &sll_ldisc);
1551 pr_err("sllin: can't register line discipline\n");
1555 #ifdef BREAK_BY_BAUD
1556 pr_debug("sllin: Break is generated by baud-rate change.");
1558 pr_debug("sllin: Break is generated manually with tiny sleep.");
1564 static void __exit sllin_exit(void)
1567 struct net_device *dev;
1569 unsigned long timeout = jiffies + HZ;
1572 if (sllin_devs == NULL)
1575 /* First of all: check for active disciplines and hangup them.
1579 msleep_interruptible(100);
1582 for (i = 0; i < maxdev; i++) {
1583 dev = sllin_devs[i];
1586 sl = netdev_priv(dev);
1587 spin_lock_bh(&sl->lock);
1590 tty_hangup(sl->tty);
1592 spin_unlock_bh(&sl->lock);
1594 } while (busy && time_before(jiffies, timeout));
1596 /* FIXME: hangup is async so we should wait when doing this second
1599 for (i = 0; i < maxdev; i++) {
1600 dev = sllin_devs[i];
1603 sllin_devs[i] = NULL;
1605 sl = netdev_priv(dev);
1607 netdev_dbg(sl->dev, "tty discipline still running\n");
1608 /* Intentionally leak the control block. */
1609 dev->destructor = NULL;
1612 unregister_netdev(dev);
1618 i = tty_unregister_ldisc(N_SLLIN);
1620 pr_err("sllin: can't unregister ldisc (err %d)\n", i);
1623 module_init(sllin_init);
1624 module_exit(sllin_exit);