X-Git-Url: http://rtime.felk.cvut.cz/gitweb/linux-lin.git/blobdiff_plain/8f3d98d43055efc074ba98ac692052386ad7e3cb..474bb86f80d53844e699fcab0fa7360900bfa025:/sllin/sllin.c diff --git a/sllin/sllin.c b/sllin/sllin.c index d223e19..03d6137 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 @@ -57,6 +54,11 @@ #include #include #include +#include +#include + +/* Should be in include/linux/tty.h */ +#define N_SLLIN 25 static __initdata const char banner[] = KERN_INFO "sllin: serial line LIN interface driver\n"; @@ -64,9 +66,10 @@ 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 BREAK_BY_BAUD static int maxdev = 10; /* MAX number of SLLIN channels; This can be overridden with @@ -74,8 +77,53 @@ 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_ID_MASK 0x3f +#define SLLIN_ID_MAX SLLIN_ID_MASK +#define SLLIN_CTRL_FRAME CAN_EFF_FLAG + +#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 */ +#define SLLIN_CANFR_FLAGS_OFFS 6 /* Lower 6 bits in can_id correspond to LIN ID */ +/* Save configuration for particular LIN ID */ +#define SLLIN_LIN_ID_CONF (1 << SLLIN_CANFR_FLAGS_OFFS) +/* Publisher of particular LIN response is SLLIN Master */ +#define SLLIN_SRC_MASTER (1 << (SLLIN_CANFR_FLAGS_OFFS + 1)) +#define SLLIN_SRC_SLAVE (1 << (SLLIN_CANFR_FLAGS_OFFS + 2)) +#define SLLIN_SLAVE_LOCAL (1 << (SLLIN_CANFR_FLAGS_OFFS + 3)) +#define SLLIN_SLAVE_REMOTE (1 << (SLLIN_CANFR_FLAGS_OFFS + 4)) +#define SLLIN_LOC_SLAVE_CACHE (1 << (SLLIN_CANFR_FLAGS_OFFS + 5)) +#define SLLIN_CHECKSUM_EXTENDED (1 << (SLLIN_CANFR_FLAGS_OFFS + 6)) + +#define SLLIN_ERR_RX_TIMEOUT (1 << (SLLIN_CANFR_FLAGS_OFFS + 7)) +#define SLLIN_ERR_CHECKSUM (1 << (SLLIN_CANFR_FLAGS_OFFS + 8)) +//#define SLLIN_ERR_FRAMING (1 << (SLLIN_CANFR_FLAGS_OFFS + 9)) + + 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; @@ -85,128 +133,92 @@ 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; - pid_t pid; + struct task_struct *kwthread; + wait_queue_head_t kwt_wq; + struct hrtimer rx_timer; /* RX timeout timer */ + ktime_t rx_timer_timeout; /* RX timeout timer value */ + struct sk_buff *tx_req_skb; /* Socket buffer with CAN frame received + from network stack*/ + + struct sllin_conf_entry linfr_cache[SLLIN_ID_MAX + 1]; /* List with configurations for + each of 0 to SLLIN_ID_MAX LIN IDs */ }; static struct net_device **sllin_devs; +static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf); + + +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 +}; - /************************************************************************ - * SLLIN ENCAPSULATION FORMAT * - ************************************************************************/ - -/* - * A CAN frame has a can_id (11 bit standard frame format OR 29 bit extended - * frame format) a data length code (can_dlc) which can be from 0 to 8 - * and up to data bytes as payload. - * Additionally a CAN frame may become a remote transmission frame if the - * RTR-bit is set. This causes another ECU to send a CAN frame with the - * given can_id. - * - * The SLLIN ASCII representation of these different frame types is: - * * - * - * Extended frames (29 bit) are defined by capital characters in the type. - * RTR frames are defined as 'r' types - normal frames have 't' type: - * t => 11 bit data frame - * r => 11 bit RTR frame - * T => 29 bit data frame - * R => 29 bit RTR frame - * - * The is 3 (standard) or 8 (extended) bytes in ASCII Hex (base64). - * The is a one byte ASCII number ('0' - '8') - * The section has at much ASCII Hex bytes as defined by the - * - * Examples: - * - * t1230 : can_id 0x123, can_dlc 0, no data - * t4563112233 : can_id 0x456, can_dlc 3, data 0x11 0x22 0x33 - * T12ABCDEF2AA55 : extended can_id 0x12ABCDEF, can_dlc 2, data 0xAA 0x55 - * r1230 : can_id 0x123, can_dlc 0, no data, remote transmission request - * - */ +static int sltty_change_speed(struct tty_struct *tty, unsigned speed) +{ + struct ktermios old_termios; + int cflag; - /************************************************************************ - * STANDARD SLLIN DECAPSULATION * - ************************************************************************/ + mutex_lock(&tty->termios_mutex); -static int asc2nibble(char c) -{ + old_termios = *(tty->termios); + cflag = tty->termios->c_cflag; + cflag &= ~(CBAUD | CIBAUD); + cflag |= BOTHER; + tty->termios->c_cflag = cflag; - if ((c >= '0') && (c <= '9')) - return c - '0'; + tty_encode_baud_rate(tty, speed, speed); - if ((c >= 'A') && (c <= 'F')) - return c - 'A' + 10; + if (tty->ops->set_termios) + tty->ops->set_termios(tty, &old_termios); - if ((c >= 'a') && (c <= 'f')) - return c - 'a' + 10; + mutex_unlock(&tty->termios_mutex); - return 16; /* error */ + return 0; } -/* Send one completely decapsulated can_frame to the network layer */ -static void sll_bump(struct sllin *sl) + +/* 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; - 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; + cf.can_id = id; + cf.can_dlc = len; + if (cf.can_dlc > 0) { + memcpy(&cf.data, data, cf.can_dlc); } - skb = dev_alloc_skb(sizeof(struct can_frame)); if (!skb) return; @@ -221,73 +233,15 @@ static void sll_bump(struct sllin *sl) 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) -{ - 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); - } - } - } } - /************************************************************************ - * STANDARD SLLIN ENCAPSULATION * - ************************************************************************/ - -/* Encapsulate one can_frame and stuff into a TTY queue. */ -static void sll_encaps(struct sllin *sl, struct can_frame *cf) +static void sll_bump(struct sllin *sl) { - int actual, idx, i; - char cmd; - - if (cf->can_id & CAN_RTR_FLAG) - cmd = 'R'; /* becomes 'r' in standard frame format */ - else - cmd = 'T'; /* becomes 't' in standard frame format */ - - if (cf->can_id & CAN_EFF_FLAG) - sprintf(sl->xbuff, "%c%08X%d", cmd, - cf->can_id & CAN_EFF_MASK, cf->can_dlc); - else - sprintf(sl->xbuff, "%c%03X%d", cmd | 0x20, - cf->can_id & CAN_SFF_MASK, cf->can_dlc); - - idx = strlen(sl->xbuff); - - for (i = 0; i < cf->can_dlc; i++) - sprintf(&sl->xbuff[idx + 2*i], "%02X", cf->data[i]); - - strcat(sl->xbuff, "\r"); /* add terminating character */ - - /* 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; + sllin_send_canfr(sl, sl->rx_buff[SLLIN_BUFF_ID] & SLLIN_ID_MASK, + sl->rx_buff + SLLIN_BUFF_DATA, + sl->rx_cnt - SLLIN_BUFF_DATA - 1); /* without checksum */ } /* @@ -297,50 +251,72 @@ 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) { + printk(KERN_INFO "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); + + printk(KERN_INFO "sllin_write_wakeup sent %d, wakeup\n", sl->tx_cnt); } /* Send a can_frame to a TTY queue. */ 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 & SLLIN_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; } @@ -361,8 +337,8 @@ 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; @@ -373,6 +349,8 @@ static int sll_open(struct net_device *dev) { struct sllin *sl = netdev_priv(dev); + pr_debug("sllin: %s() invoked\n", __FUNCTION__); + if (sl->tty == NULL) return -ENODEV; @@ -430,6 +408,8 @@ static void sllin_receive_buf(struct tty_struct *tty, { struct sllin *sl = (struct sllin *) tty->disc_data; + printk(KERN_INFO "sllin_receive_buf invoked\n"); + if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev)) return; @@ -438,13 +418,503 @@ 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++; + printk(KERN_INFO "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 + printk(KERN_INFO "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); + printk(KERN_INFO "sllin_receive_buf count %d, wakeup\n", sl->rx_cnt); + } else { + printk(KERN_INFO "sllin_receive_buf count %d, waiting\n", sl->rx_cnt); } } +/***************************************** + * sllin message helper routines + *****************************************/ +void sllin_report_error(struct sllin *sl, int err) +{ + sllin_send_canfr(sl, 0 | CAN_EFF_FLAG | + (err & ~SLLIN_ID_MASK), NULL, 0); +} + +static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf) +{ + struct sllin_conf_entry *sce; + if (!(cf->can_id & SLLIN_LIN_ID_CONF)) + return -1; + + sce = &sl->linfr_cache[cf->can_id & SLLIN_ID_MASK]; + printk(KERN_INFO "Setting frame cache with EFF CAN frame. " + "LIN ID = %d\n", cf->can_id & SLLIN_ID_MASK); + + sce->dlc = cf->can_dlc; + if (sce->dlc > SLLIN_DATA_MAX) + sce->dlc = SLLIN_DATA_MAX; + + sce->frame_fl = (cf->can_id & ~SLLIN_ID_MASK) & CAN_EFF_MASK; + memcpy(sce->data, cf->data, cf->can_dlc); + + return 0; +} + +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 > SLLIN_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; + } + + printk(KERN_INFO "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; + + printk(KERN_INFO "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, SLLIN_ERR_RX_TIMEOUT); + set_bit(SLF_TMOUTEVENT, &sl->flags); + wake_up(&sl->kwt_wq); + + return HRTIMER_NORESTART; +} + +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] & SLLIN_ID_MASK; + scf = &sl->linfr_cache[actual_id]; + lin_dlc = scf->dlc; + ext_chcks_fl = scf->frame_fl & SLLIN_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; +} + +/***************************************** + * sllin_kwthread - kernel worker thread + *****************************************/ + +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"); + sched_setscheduler(current, SCHED_FIFO, &schparam); + + clear_bit(SLF_ERROR, &sl->flags); + sltty_change_speed(tty, sl->lin_baud); + + while (!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)) { + printk(KERN_INFO "sllin_kthread RXEVENT \n"); + } + + if (test_and_clear_bit(SLF_TXEVENT, &sl->flags)) { + printk(KERN_INFO "sllin_kthread TXEVENT \n"); + } + + if (test_and_clear_bit(SLF_TMOUTEVENT, &sl->flags)) { + printk(KERN_INFO "sllin_kthread TMOUTEVENT \n"); + sl->rx_cnt = 0; + sl->rx_expect = 0; + sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN; + sl->tx_cnt = 0; + sl->tx_lim = 0; + sl->id_to_send = false; + sl->data_to_send = false; + + sl->lin_state = SLSTATE_IDLE; + } + + 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); + printk(KERN_INFO "%s: RTR SFF CAN frame, ID = %x\n", + __FUNCTION__, cf->can_id & SLLIN_ID_MASK); + + /* Is there Slave response in linfr_cache to be sent? */ + if ((sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].frame_fl & + SLLIN_LOC_SLAVE_CACHE) + && (sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].dlc > 0)) { + + printk(KERN_INFO "Sending LIN response from linfr_cache\n"); + lin_data = sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].data; + lin_dlc = sl->linfr_cache[cf->can_id & SLLIN_ID_MASK].dlc; + 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 & SLLIN_ID_MASK].dlc; + } + spin_unlock(&sl->lock); + } else { /* SFF NON-RTR CAN frame -> LIN header + LIN response */ + printk(KERN_INFO "%s: NON-RTR SFF CAN frame, ID = %x\n", + __FUNCTION__, (int)cf->can_id & SLLIN_ID_MASK); + + 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 & SLLIN_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); + 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: + 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] & SLLIN_ID_MASK)) { + if (sllin_setup_msg(sl, SLLIN_STPMSG_RESPONLY, + cf->can_id & SLLIN_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; + } + } + + case SLSTATE_RESPONSE_WAIT_BUS: + if (sl->rx_cnt < sl->rx_expect) + continue; + + hrtimer_cancel(&sl->rx_timer); + printk(KERN_INFO "sllin: response received ID %d len %d\n", + sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1); + + if (sllin_rx_validate(sl) == -1) { + printk("sllin: RX validation failed.\n"); + sllin_report_error(sl, SLLIN_ERR_CHECKSUM); + //FIXME tx_stat.err++ + } else { + // send CAN non-RTR frame with data + printk(KERN_INFO "sllin: sending NON-RTR CAN" + "frame with LIN payload."); + sll_bump(sl); //send packet to the network layer + } + + sl->id_to_send = false; + sl->lin_state = SLSTATE_IDLE; + break; + + case SLSTATE_RESPONSE_SENT: + slstate_response_sent: + if (sl->rx_cnt < sl->tx_lim) + continue; + + sll_bump(sl); //send packet to the network layer + printk(KERN_INFO "sllin: response sent ID %d len %d\n", + sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1); + + sl->id_to_send = false; + sl->lin_state = SLSTATE_IDLE; + break; + } + + + + + /* sl->dev->stats.tx_packets++; send frames statistic */ + /* netif_wake_queue(sl->dev); allow next Tx packet arrival */ + } + + hrtimer_cancel(&sl->rx_timer); + printk(KERN_INFO "sllin: sllin_kwthread stopped.\n"); + + return 0; +} + + /************************************ * sllin_open helper routines. ************************************/ @@ -462,7 +932,7 @@ 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); @@ -510,7 +980,6 @@ static struct sllin *sll_alloc(dev_t line) } sl = netdev_priv(dev); - /* Initialize channel control data */ sl->magic = SLLIN_MAGIC; sl->dev = dev; @@ -534,6 +1003,7 @@ static int sllin_open(struct tty_struct *tty) { struct sllin *sl; int err; + pr_debug("sllin: %s() invoked\n", __FUNCTION__); if (!capable(CAP_NET_ADMIN)) return -EPERM; @@ -566,27 +1036,53 @@ static int sllin_open(struct tty_struct *tty) sl->tty = tty; tty->disc_data = sl; sl->line = tty_devnum(tty); - sl->pid = current->pid; 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); + init_waitqueue_head(&sl->kwt_wq); + sl->kwthread = kthread_run(sllin_kwthread, sl, "sllin"); + if (sl->kwthread == NULL) + goto err_free_chan; + err = register_netdevice(sl->dev); if (err) - goto err_free_chan; + goto err_free_chan_and_thread; } /* 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; +err_free_chan_and_thread: + kthread_stop(sl->kwthread); + sl->kwthread = NULL; + err_free_chan: sl->tty = NULL; tty->disc_data = NULL; @@ -615,10 +1111,11 @@ static void sllin_close(struct tty_struct *tty) if (!sl || sl->magic != SLLIN_MAGIC || sl->tty != tty) return; + kthread_stop(sl->kwthread); + sl->kwthread = NULL; + tty->disc_data = NULL; sl->tty = NULL; - if (!sl->leased) - sl->line = 0; /* Flush network side */ unregister_netdev(sl->dev); @@ -691,6 +1188,13 @@ static int __init sllin_init(void) printk(KERN_ERR "sllin: can't register line discipline\n"); kfree(sllin_devs); } + +#ifdef BREAK_BY_BAUD + printk(KERN_INFO "sllin: Break is generated by baud-rate change."); +#else + printk(KERN_INFO "sllin: Break is generated manually with tiny sleep."); +#endif + return status; }