X-Git-Url: http://rtime.felk.cvut.cz/gitweb/linux-lin.git/blobdiff_plain/ea28a0514e25c0de0199f141b083780faaffccbf..399c19f1b3e62f76c7f5baf29a2b5c366d341335:/sllin/sllin.c diff --git a/sllin/sllin.c b/sllin/sllin.c index 7793541..6a4e8bf 100644 --- a/sllin/sllin.c +++ b/sllin/sllin.c @@ -1,11 +1,8 @@ /* * 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 - * Fred N. van Kempen - * sllin.c Author : Oliver Hartkopp + * This file is derived from drivers/net/can/slcan.c + * slcan.c Author: Oliver Hartkopp * * 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 @@ -39,6 +36,8 @@ * */ +#define DEBUG 1 /* Enables pr_debug() printouts */ + #include #include @@ -58,9 +57,12 @@ #include #include #include +#include +#include "linux/lin_bus.h" /* Should be in include/linux/tty.h */ -#define N_SLLIN 25 +#define N_SLLIN 25 +/* -------------------------------- */ static __initdata const char banner[] = KERN_INFO "sllin: serial line LIN interface driver\n"; @@ -68,9 +70,10 @@ static __initdata const char banner[] = MODULE_ALIAS_LDISC(N_SLLIN); MODULE_DESCRIPTION("serial line LIN interface"); MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Oliver Hartkopp "); +MODULE_AUTHOR(""); -#define SLLIN_MAGIC 0x53CA +#define SLLIN_MAGIC 0x53CA +/* #define BREAK_BY_BAUD */ static int maxdev = 10; /* MAX number of SLLIN channels; This can be overridden with @@ -78,8 +81,35 @@ static int maxdev = 10; /* MAX number of SLLIN channels; module_param(maxdev, int, 0); MODULE_PARM_DESC(maxdev, "Maximum number of sllin interfaces"); -/* maximum rx buffer len: extended CAN frame with timestamp */ -#define SLC_MTU (sizeof("T1111222281122334455667788EA5F\r")+1) +/* maximum buffer len to store whole LIN message*/ +#define SLLIN_DATA_MAX 8 +#define SLLIN_BUFF_LEN (1 /*break*/ + 1 /*sync*/ + 1 /*ID*/ + \ + SLLIN_DATA_MAX + 1 /*checksum*/) +#define SLLIN_BUFF_BREAK 0 +#define SLLIN_BUFF_SYNC 1 +#define SLLIN_BUFF_ID 2 +#define SLLIN_BUFF_DATA 3 + +#define SLLIN_SAMPLES_PER_CHAR 10 +#define SLLIN_CHARS_TO_TIMEOUT 12 + +enum slstate { + SLSTATE_IDLE = 0, + SLSTATE_BREAK_SENT, + SLSTATE_ID_SENT, + SLSTATE_RESPONSE_WAIT, /* Wait for response */ + SLSTATE_RESPONSE_WAIT_BUS, /* Wait for response from LIN bus + only (CAN frames from network stack + are not processed in this moment) */ + SLSTATE_RESPONSE_SENT, +}; + +struct sllin_conf_entry { + int dlc; /* Length of data in LIN frame */ + 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; @@ -89,183 +119,130 @@ struct sllin { struct net_device *dev; /* easy for intr handling */ spinlock_t lock; - /* These are pointers to the malloc()ed frame buffers. */ - unsigned char rbuff[SLC_MTU]; /* receiver buffer */ - int rcount; /* received chars counter */ - unsigned char xbuff[SLC_MTU]; /* transmitter buffer */ - unsigned char *xhead; /* pointer to next XMIT byte */ - int xleft; /* bytes left in XMIT queue */ + /* LIN message buffer and actual processed data counts */ + 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 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 */ + char id_to_send; /* there is ID to be sent */ + char data_to_send; /* there are data to be sent */ + char resp_len_known; /* Length of the response is known */ unsigned long flags; /* Flag values/ mode etc */ #define SLF_INUSE 0 /* Channel in use */ #define SLF_ERROR 1 /* Parity, etc. error */ +#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 */ - unsigned char leased; dev_t line; struct task_struct *kwthread; - wait_queue_head_t kwt_wq; + wait_queue_head_t kwt_wq; /* Wait queue used by kwthread */ + struct hrtimer rx_timer; /* RX timeout timer */ + ktime_t rx_timer_timeout; /* RX timeout timer value */ + struct sk_buff *tx_req_skb; /* Socket buffer with CAN frame + received from network stack*/ + + /* List with configurations for each of 0 to LIN_ID_MAX LIN IDs */ + struct sllin_conf_entry linfr_cache[LIN_ID_MAX + 1]; }; static struct net_device **sllin_devs; +static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf); + + +/* Values of two parity bits in LIN Protected + Identifier for each particular LIN ID */ +const unsigned char sllin_id_parity_table[] = { + 0x80, 0xc0, 0x40, 0x00, 0xc0, 0x80, 0x00, 0x40, + 0x00, 0x40, 0xc0, 0x80, 0x40, 0x00, 0x80, 0xc0, + 0x40, 0x00, 0x80, 0xc0, 0x00, 0x40, 0xc0, 0x80, + 0xc0, 0x80, 0x00, 0x40, 0x80, 0xc0, 0x40, 0x00, + 0x00, 0x40, 0xc0, 0x80, 0x40, 0x00, 0x80, 0xc0, + 0x80, 0xc0, 0x40, 0x00, 0xc0, 0x80, 0x00, 0x40, + 0xc0, 0x80, 0x00, 0x40, 0x80, 0xc0, 0x40, 0x00, + 0x40, 0x00, 0x80, 0xc0, 0x00, 0x40, 0xc0, 0x80 +}; - +/** + * sltty_change_speed() -- Change baudrate of Serial device belonging + * to particular @tty + * + * @tty: Pointer to TTY to change speed for. + * @speed: Integer value of new speed. It is possible to + * assign non-standard values, i.e. those which + * are not defined in termbits.h. + */ static int sltty_change_speed(struct tty_struct *tty, unsigned speed) { struct ktermios old_termios; int cflag; mutex_lock(&tty->termios_mutex); + old_termios = *(tty->termios); cflag = tty->termios->c_cflag; + cflag &= ~(CBAUD | CIBAUD); + cflag |= BOTHER; + tty->termios->c_cflag = cflag; + tty_encode_baud_rate(tty, speed, speed); + if (tty->ops->set_termios) tty->ops->set_termios(tty, &old_termios); - //priv->io.speed = speed; + mutex_unlock(&tty->termios_mutex); return 0; } -/* 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; -} - -/* parse tty input stream */ -static void sllin_unesc(struct sllin *sl, unsigned char s) +/* Send one can_frame to the network layer */ +static void sllin_send_canfr(struct sllin *sl, canid_t id, char *data, int len) { + struct sk_buff *skb; + struct can_frame cf; - if ((s == '\r') || (s == '\a')) { /* CR or BEL ends the pdu */ - if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && - (sl->rcount > 4)) { - sll_bump(sl); - } - sl->rcount = 0; - } else { - if (!test_bit(SLF_ERROR, &sl->flags)) { - if (sl->rcount < SLC_MTU) { - sl->rbuff[sl->rcount++] = s; - return; - } else { - sl->dev->stats.rx_over_errors++; - set_bit(SLF_ERROR, &sl->flags); - } - } + cf.can_id = id; + cf.can_dlc = len; + if (cf.can_dlc > 0) { + memcpy(&cf.data, data, cf.can_dlc); } -} - /************************************************************************ - * STANDARD SLLIN ENCAPSULATION * - ************************************************************************/ - -/* 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) + skb = dev_alloc_skb(sizeof(struct can_frame)); + if (!skb) 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 */ + 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); - sltty_change_speed(tty, 1200); - tty->ops->write(tty, &lframe[0], 1); - sltty_change_speed(tty, 2400); - 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; - */ - } + sl->dev->stats.rx_packets++; + sl->dev->stats.rx_bytes += cf.can_dlc; +} +/** + * sll_bump() -- Send data of received LIN frame (existing in sl->rx_buff) + * as CAN frame + * + * @sl: + */ +static void sll_bump(struct sllin *sl) +{ + sllin_send_canfr(sl, sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK, + sl->rx_buff + SLLIN_BUFF_DATA, + sl->rx_cnt - SLLIN_BUFF_DATA - 1); /* without checksum */ } /* @@ -275,50 +252,79 @@ static void sll_encaps(struct sllin *sl, struct can_frame *cf) static void sllin_write_wakeup(struct tty_struct *tty) { int actual; + int remains; 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->xleft <= 0) { - /* Now serial buffer is almost free & we can start - * transmission of another packet */ - sl->dev->stats.tx_packets++; - clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); - netif_wake_queue(sl->dev); - return; + if (sl->lin_state != SLSTATE_BREAK_SENT) + remains = sl->tx_lim - sl->tx_cnt; + else + remains = SLLIN_BUFF_BREAK + 1 - sl->tx_cnt; + + if (remains > 0) { + actual = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, + sl->tx_cnt - sl->tx_lim); + sl->tx_cnt += actual; + + if (sl->tx_cnt < sl->tx_lim) { + pr_debug("sllin: sllin_write_wakeup sent %d, " + "remains %d, waiting\n", + sl->tx_cnt, sl->tx_lim - sl->tx_cnt); + return; + } } - actual = tty->ops->write(tty, sl->xhead, sl->xleft); - sl->xleft -= actual; - sl->xhead += actual; + clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + set_bit(SLF_TXEVENT, &sl->flags); + wake_up(&sl->kwt_wq); + + pr_debug("sllin: sllin_write_wakeup sent %d, wakeup\n", sl->tx_cnt); } -/* Send a can_frame to a TTY queue. */ +/** + * sll_xmit() -- Send a can_frame to a TTY queue. + * + * @skb: Pointer to Socket buffer to be sent. + * @dev: Network device where @skb will be sent. + */ static netdev_tx_t sll_xmit(struct sk_buff *skb, struct net_device *dev) { struct sllin *sl = netdev_priv(dev); + struct can_frame *cf; 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_unlock; } if (sl->tty == NULL) { - spin_unlock(&sl->lock); - goto out; + goto err_out_unlock; + } + + cf = (struct can_frame *) skb->data; + if (cf->can_id & LIN_CTRL_FRAME) { + sllin_configure_frame_cache(sl, cf); + goto free_out_unlock; } netif_stop_queue(sl->dev); - sll_encaps(sl, (struct can_frame *) skb->data); /* encaps & send */ + + sl->tx_req_skb = skb; + set_bit(SLF_MSGEVENT, &sl->flags); + wake_up(&sl->kwt_wq); spin_unlock(&sl->lock); + return NETDEV_TX_OK; -out: +free_out_unlock: +err_out_unlock: + spin_unlock(&sl->lock); +err_out: kfree_skb(skb); return NETDEV_TX_OK; } @@ -339,8 +345,8 @@ static int sll_close(struct net_device *dev) clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); } netif_stop_queue(dev); - sl->rcount = 0; - sl->xleft = 0; + sl->rx_expect = 0; + sl->tx_lim = 0; spin_unlock_bh(&sl->lock); return 0; @@ -396,20 +402,13 @@ static void sll_setup(struct net_device *dev) Routines looking at TTY side. ******************************************/ -/* - * Handle the 'receiver data ready' interrupt. - * This function is called by the 'tty_io' module in the kernel when - * a block of SLLIN data has been received, which can now be decapsulated - * and sent on to some IP layer for further processing. This will not - * be re-entered while running but other ldisc functions may be called - * in parallel - */ - static void sllin_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) { struct sllin *sl = (struct sllin *) tty->disc_data; + pr_debug("sllin: sllin_receive_buf invoked\n"); + if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev)) return; @@ -418,11 +417,303 @@ static void sllin_receive_buf(struct tty_struct *tty, if (fp && *fp++) { if (!test_and_set_bit(SLF_ERROR, &sl->flags)) sl->dev->stats.rx_errors++; + pr_debug("sllin: sllin_receive_buf char 0x%02x ignored " + "due marker 0x%02x, flags 0x%lx\n", + *cp, *(fp-1), sl->flags); cp++; continue; } - sllin_unesc(sl, *cp++); + + if (sl->rx_cnt < SLLIN_BUFF_LEN) { +#ifndef BREAK_BY_BAUD + /* We didn't receive Break character */ + if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) { + sl->rx_buff[sl->rx_cnt++] = 0x00; + } +#endif + pr_debug("sllin: LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp); + sl->rx_buff[sl->rx_cnt++] = *cp++; + } + } + + if (sl->rx_cnt >= sl->rx_expect) { + set_bit(SLF_RXEVENT, &sl->flags); + wake_up(&sl->kwt_wq); + pr_debug("sllin: sllin_receive_buf count %d, wakeup\n", sl->rx_cnt); + } else { + pr_debug("sllin: sllin_receive_buf count %d, waiting\n", sl->rx_cnt); + } +} + +/***************************************** + * sllin message helper routines + *****************************************/ +/** + * sllin_report_error() -- Report an error by sending CAN frame + * with particular error flag set in can_id + * + * @sl: + * @err: Error flag to be sent. + */ +void sllin_report_error(struct sllin *sl, int err) +{ + switch (err) { + case LIN_ERR_CHECKSUM: + sl->dev->stats.rx_crc_errors++; + break; + + case LIN_ERR_RX_TIMEOUT: + sl->dev->stats.rx_errors++; + break; + } + + sllin_send_canfr(sl, 0 | CAN_EFF_FLAG | + (err & ~LIN_ID_MASK), NULL, 0); +} + +/** + * sllin_configure_frame_cache() -- Configure particular entry in linfr_cache + * + * @sl: + * @cf: Pointer to CAN frame sent to this driver + * holding configuration information + */ +static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf) +{ + struct sllin_conf_entry *sce; + if (!(cf->can_id & LIN_ID_CONF)) + return -1; + + sce = &sl->linfr_cache[cf->can_id & LIN_ID_MASK]; + pr_debug("sllin: Setting frame cache with EFF CAN frame. " + "LIN ID = %d\n", cf->can_id & LIN_ID_MASK); + + sce->dlc = cf->can_dlc; + if (sce->dlc > SLLIN_DATA_MAX) + sce->dlc = SLLIN_DATA_MAX; + + sce->frame_fl = (cf->can_id & ~LIN_ID_MASK) & CAN_EFF_MASK; + memcpy(sce->data, cf->data, cf->can_dlc); + + return 0; +} + +/** + * sllin_checksum() -- Count checksum for particular data + * + * @data: Pointer to the buffer containing whole LIN + * frame (i.e. including break and sync bytes). + * @length: Length of the buffer. + * @enhanced_fl: Flag determining whether Enhanced or Classic + * checksum should be counted. + */ +static inline unsigned sllin_checksum(unsigned char *data, int length, int enhanced_fl) +{ + unsigned csum = 0; + int i; + + if (enhanced_fl) { + i = SLLIN_BUFF_ID; + } else { + i = SLLIN_BUFF_DATA; + } + + for (; i < length; i++) { + csum += data[i]; + if (csum > 255) + csum -= 255; + } + + return ~csum & 0xff; +} + +#define SLLIN_STPMSG_RESPONLY (1) /* Message will be LIN Response only */ +#define SLLIN_STPMSG_CHCKSUM_CLS (1 << 1) +#define SLLIN_STPMSG_CHCKSUM_ENH (1 << 2) + +int sllin_setup_msg(struct sllin *sl, int mode, int id, + unsigned char *data, int len) +{ + if (id > LIN_ID_MASK) + return -1; + + if (!(mode & SLLIN_STPMSG_RESPONLY)) { + 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[SLLIN_BUFF_ID] = id | sllin_id_parity_table[id]; + sl->tx_lim = SLLIN_BUFF_DATA; + + if ((data != NULL) && len) { + sl->tx_lim += len; + memcpy(sl->tx_buff + SLLIN_BUFF_DATA, data, len); + sl->tx_buff[sl->tx_lim++] = sllin_checksum(sl->tx_buff, + sl->tx_lim, mode & SLLIN_STPMSG_CHCKSUM_ENH); + } + if (len != 0) + sl->rx_lim = SLLIN_BUFF_DATA + len + 1; + + return 0; +} + + +int sllin_send_tx_buff(struct sllin *sl) +{ + struct tty_struct *tty = sl->tty; + int remains; + int res; + +#ifdef BREAK_BY_BAUD + if (sl->lin_state != SLSTATE_BREAK_SENT) + remains = sl->tx_lim - sl->tx_cnt; + else + remains = 1; +#else + remains = sl->tx_lim - sl->tx_cnt; +#endif + + res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains); + if (res < 0) + return -1; + + remains -= res; + sl->tx_cnt += res; + + if (remains > 0) { + set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + res = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, remains); + if (res < 0) { + clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + return -1; + } + + remains -= res; + sl->tx_cnt += res; + } + + pr_debug("sllin: sllin_send_tx_buff sent %d, remains %d\n", + sl->tx_cnt, remains); + + return 0; +} + +#ifdef BREAK_BY_BAUD +int sllin_send_break(struct sllin *sl) +{ + struct tty_struct *tty = sl->tty; + unsigned long break_baud; + int res; + + break_baud = ((sl->lin_baud * 2) / 3); + sltty_change_speed(tty, break_baud); + + tty->ops->flush_buffer(tty); + sl->rx_cnt = SLLIN_BUFF_BREAK; + + sl->rx_expect = SLLIN_BUFF_BREAK + 1; + sl->lin_state = SLSTATE_BREAK_SENT; + + res = sllin_send_tx_buff(sl); + if (res < 0) { + sl->lin_state = SLSTATE_IDLE; + return res; + } + + return 0; +} +#else /* BREAK_BY_BAUD */ + +int sllin_send_break(struct sllin *sl) +{ + struct tty_struct *tty = sl->tty; + int retval; + unsigned long break_baud; + unsigned long usleep_range_min; + unsigned long usleep_range_max; + + break_baud = ((sl->lin_baud * 2) / 3); + sl->rx_cnt = SLLIN_BUFF_BREAK; + sl->rx_expect = SLLIN_BUFF_BREAK + 1; + sl->lin_state = SLSTATE_BREAK_SENT; + + /* Do the break ourselves; Inspired by + http://lxr.linux.no/#linux+v3.1.2/drivers/tty/tty_io.c#L2452 */ + retval = tty->ops->break_ctl(tty, -1); + if (retval) + return retval; + + /* udelay(712); */ + usleep_range_min = (1000000l * SLLIN_SAMPLES_PER_CHAR) / break_baud; + usleep_range_max = usleep_range_min + 50; + usleep_range(usleep_range_min, usleep_range_max); + + retval = tty->ops->break_ctl(tty, 0); + usleep_range_min = (1000000l * 1 /* 1 bit */) / break_baud; + usleep_range_max = usleep_range_min + 30; + usleep_range(usleep_range_min, usleep_range_max); + + tty->ops->flush_buffer(tty); + + sl->tx_cnt = SLLIN_BUFF_SYNC; + + pr_debug("sllin: Break sent.\n"); + set_bit(SLF_RXEVENT, &sl->flags); + wake_up(&sl->kwt_wq); + + 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); + + sllin_report_error(sl, LIN_ERR_RX_TIMEOUT); + set_bit(SLF_TMOUTEVENT, &sl->flags); + wake_up(&sl->kwt_wq); + + return HRTIMER_NORESTART; +} + +/** + * sllin_rx_validate() -- Validate received frame, i,e. check checksum + * + * @sl: + */ +static int sllin_rx_validate(struct sllin *sl) +{ + int actual_id; + int ext_chcks_fl; + int lin_dlc; + unsigned char rec_chcksm = sl->rx_buff[sl->rx_cnt - 1]; + struct sllin_conf_entry *scf; + + actual_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK; + scf = &sl->linfr_cache[actual_id]; + lin_dlc = scf->dlc; + ext_chcks_fl = scf->frame_fl & LIN_CHECKSUM_EXTENDED; + + if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1, ext_chcks_fl) != + rec_chcksm) { + + /* Type of checksum is configured for particular frame */ + if (lin_dlc > 0) { + return -1; + } else { + if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1, + !ext_chcks_fl) != rec_chcksm) { + return -1; + } + } } + + return 0; } /***************************************** @@ -432,16 +723,228 @@ static void sllin_receive_buf(struct tty_struct *tty, int sllin_kwthread(void *ptr) { struct sllin *sl = (struct sllin *)ptr; + struct tty_struct *tty = sl->tty; + struct sched_param schparam = { .sched_priority = 40 }; + int tx_bytes = 0; /* Used for Network statistics */ - printk(KERN_INFO "sllin: sllin_kwthread started.\n"); + + pr_debug("sllin: sllin_kwthread started.\n"); + sched_setscheduler(current, SCHED_FIFO, &schparam); + + clear_bit(SLF_ERROR, &sl->flags); + sltty_change_speed(tty, sl->lin_baud); while (!kthread_should_stop()) { - - wait_event_killable(sl->kwt_wq, kthread_should_stop()); + struct can_frame *cf; + u8 *lin_data; + int lin_dlc; + u8 lin_data_buff[SLLIN_DATA_MAX]; + + + if ((sl->lin_state == SLSTATE_IDLE) && sl->lin_master && + sl->id_to_send) { + if(sllin_send_break(sl) < 0) { + /* error processing */ + } + } + + 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) || + (sl->lin_state == SLSTATE_RESPONSE_WAIT)) + && test_bit(SLF_MSGEVENT, &sl->flags))); + + if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) { + pr_debug("sllin: sllin_kthread RXEVENT\n"); + } + + if (test_and_clear_bit(SLF_TXEVENT, &sl->flags)) { + pr_debug("sllin: sllin_kthread TXEVENT\n"); + } + if (test_and_clear_bit(SLF_TMOUTEVENT, &sl->flags)) { + pr_debug("sllin: 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; + } + + switch (sl->lin_state) { + case SLSTATE_IDLE: + if (!test_bit(SLF_MSGEVENT, &sl->flags)) + break; + + cf = (struct can_frame *)sl->tx_req_skb->data; + + /* SFF RTR CAN frame -> LIN header */ + if (cf->can_id & CAN_RTR_FLAG) { + spin_lock(&sl->lock); + pr_debug("sllin: %s: RTR SFF CAN frame, ID = %x\n", + __FUNCTION__, cf->can_id & LIN_ID_MASK); + + /* Is there Slave response in linfr_cache to be sent? */ + if ((sl->linfr_cache[cf->can_id & LIN_ID_MASK].frame_fl & + LIN_LOC_SLAVE_CACHE) + && (sl->linfr_cache[cf->can_id & LIN_ID_MASK].dlc > 0)) { + + pr_debug("sllin: Sending LIN response from linfr_cache\n"); + lin_data = sl->linfr_cache[cf->can_id & LIN_ID_MASK].data; + lin_dlc = sl->linfr_cache[cf->can_id & LIN_ID_MASK].dlc; + if (lin_dlc > SLLIN_DATA_MAX) + lin_dlc = SLLIN_DATA_MAX; + memcpy(lin_data_buff, lin_data, lin_dlc); + lin_data = lin_data_buff; + } else { + lin_data = NULL; + lin_dlc = sl->linfr_cache[cf->can_id & LIN_ID_MASK].dlc; + } + spin_unlock(&sl->lock); + } else { /* SFF NON-RTR CAN frame -> LIN header + LIN response */ + pr_debug("sllin: %s: NON-RTR SFF CAN frame, ID = %x\n", + __FUNCTION__, (int)cf->can_id & LIN_ID_MASK); + + lin_data = cf->data; + lin_dlc = cf->can_dlc; + if (lin_dlc > SLLIN_DATA_MAX) + lin_dlc = SLLIN_DATA_MAX; + tx_bytes = lin_dlc; + } + + if (sllin_setup_msg(sl, 0, cf->can_id & LIN_ID_MASK, + lin_data, lin_dlc) != -1) { + + sl->id_to_send = true; + sl->data_to_send = (lin_data != NULL) ? true : false; + sl->resp_len_known = (lin_dlc > 0) ? true : false; + sl->dev->stats.tx_packets++; + sl->dev->stats.tx_bytes += tx_bytes; + } + + clear_bit(SLF_MSGEVENT, &sl->flags); + kfree_skb(sl->tx_req_skb); + netif_wake_queue(sl->dev); + hrtimer_start(&sl->rx_timer, + ktime_add(ktime_get(), sl->rx_timer_timeout), + HRTIMER_MODE_ABS); + break; + + case SLSTATE_BREAK_SENT: +#ifdef BREAK_BY_BAUD + if (sl->rx_cnt <= SLLIN_BUFF_BREAK) + continue; + + res = sltty_change_speed(tty, sl->lin_baud); +#endif + + sl->lin_state = SLSTATE_ID_SENT; + sllin_send_tx_buff(sl); + break; + + case SLSTATE_ID_SENT: + hrtimer_cancel(&sl->rx_timer); + 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 { + if (sl->resp_len_known) { + sl->rx_expect = sl->rx_lim; + } 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 (test_bit(SLF_MSGEVENT, &sl->flags)) { + unsigned char *lin_buff; + cf = (struct can_frame *)sl->tx_req_skb->data; + + lin_buff = (sl->lin_master) ? sl->tx_buff : sl->rx_buff; + if (cf->can_id == (lin_buff[SLLIN_BUFF_ID] & LIN_ID_MASK)) { + if (sllin_setup_msg(sl, SLLIN_STPMSG_RESPONLY, + cf->can_id & LIN_ID_MASK, + cf->data, cf->can_dlc) != -1) { + + sl->rx_expect = sl->tx_lim; + sl->data_to_send = true; + sl->dev->stats.tx_packets++; + sl->dev->stats.tx_bytes += tx_bytes; + + if (!sl->lin_master) { + sl->tx_cnt = SLLIN_BUFF_DATA; + } + + sllin_send_tx_buff(sl); + clear_bit(SLF_MSGEVENT, &sl->flags); + kfree_skb(sl->tx_req_skb); + netif_wake_queue(sl->dev); + + sl->lin_state = SLSTATE_RESPONSE_SENT; + goto slstate_response_sent; + } + } else { + sl->lin_state = SLSTATE_RESPONSE_WAIT_BUS; + } + } + + /* Be aware, no BREAK here */ + case SLSTATE_RESPONSE_WAIT_BUS: + if (sl->rx_cnt < sl->rx_expect) + continue; + + hrtimer_cancel(&sl->rx_timer); + pr_debug("sllin: response received ID %d len %d\n", + sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1); + + if (sllin_rx_validate(sl) == -1) { + pr_debug("sllin: RX validation failed.\n"); + sllin_report_error(sl, LIN_ERR_CHECKSUM); + } else { + /* Send CAN non-RTR frame with data */ + pr_debug("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 */ + pr_debug("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; + } } - printk(KERN_INFO "sllin: sllin_kwthread stopped.\n"); + hrtimer_cancel(&sl->rx_timer); + pr_debug("sllin: sllin_kwthread stopped.\n"); return 0; } @@ -464,7 +967,7 @@ static void sll_sync(void) break; sl = netdev_priv(dev); - if (sl->tty || sl->leased) + if (sl->tty) continue; if (dev->flags & IFF_UP) dev_close(dev); @@ -512,7 +1015,6 @@ static struct sllin *sll_alloc(dev_t line) } sl = netdev_priv(dev); - /* Initialize channel control data */ sl->magic = SLLIN_MAGIC; sl->dev = dev; @@ -572,8 +1074,26 @@ static int sllin_open(struct tty_struct *tty) if (!test_bit(SLF_INUSE, &sl->flags)) { /* Perform the low-level SLLIN initialization. */ - sl->rcount = 0; - sl->xleft = 0; + sl->lin_master = true; + + 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_baud = 19200; + + sl->lin_state = SLSTATE_IDLE; + + 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( + (1000000000l / sl->lin_baud) * + SLLIN_SAMPLES_PER_CHAR * SLLIN_CHARS_TO_TIMEOUT); set_bit(SLF_INUSE, &sl->flags); @@ -589,7 +1109,7 @@ static int sllin_open(struct tty_struct *tty) /* Done. We have linked the TTY line to a channel. */ rtnl_unlock(); - tty->receive_room = 65536; /* We don't flow control */ + tty->receive_room = SLLIN_BUFF_LEN * 40; /* We don't flow control */ /* TTY layer expects 0 on success */ return 0; @@ -631,8 +1151,6 @@ static void sllin_close(struct tty_struct *tty) tty->disc_data = NULL; sl->tty = NULL; - if (!sl->leased) - sl->line = 0; /* Flush network side */ unregister_netdev(sl->dev); @@ -691,7 +1209,7 @@ static int __init sllin_init(void) maxdev = 4; /* Sanity */ printk(banner); - printk(KERN_INFO "sllin: %d dynamic interface channels.\n", maxdev); + pr_debug("sllin: %d dynamic interface channels.\n", maxdev); sllin_devs = kzalloc(sizeof(struct net_device *)*maxdev, GFP_KERNEL); if (!sllin_devs) { @@ -705,6 +1223,13 @@ static int __init sllin_init(void) printk(KERN_ERR "sllin: can't register line discipline\n"); kfree(sllin_devs); } + +#ifdef BREAK_BY_BAUD + pr_debug("sllin: Break is generated by baud-rate change."); +#else + pr_debug("sllin: Break is generated manually with tiny sleep."); +#endif + return status; }