-/*
+/*
* sllin.c - serial line LIN interface driver (using tty line discipline)
*
* This file is derived from drivers/net/can/slcan.c
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
- * Send feedback to <socketcan-users@lists.berlios.de>
- *
+ * Idea: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
+ * Copyright: (c) 2011 Czech Technical University in Prague
+ * (c) 2011 Volkswagen Group Research
+ * Authors: Pavel Pisa <pisa@cmp.felk.cvut.cz>
+ * Rostislav Lisovy <lisovy@kormus.cz>
+ * Michal Sojka <sojkam1@fel.cvut.cz>
+ * Funded by: Volkswagen Group Research
*/
#define DEBUG 1 /* Enables pr_debug() printouts */
MODULE_ALIAS_LDISC(N_SLLIN);
MODULE_DESCRIPTION("serial line LIN interface");
MODULE_LICENSE("GPL");
-MODULE_AUTHOR("");
+MODULE_AUTHOR("Pavel Pisa <pisa@cmp.felk.cvut.cz>");
#define SLLIN_MAGIC 0x53CA
/* #define BREAK_BY_BAUD */
+static int master = true;
+static int baudrate = 0; /* Use LIN_DEFAULT_BAUDRATE when not set */
+
+module_param(master, bool, 0);
+MODULE_PARM_DESC(master, "LIN interface is Master device");
+module_param(baudrate, int, 0);
+MODULE_PARM_DESC(baudrate, "Baudrate of LIN interface");
+
static int maxdev = 10; /* MAX number of SLLIN channels;
This can be overridden with
insmod sllin.ko maxdev=nnn */
#define SLLIN_BUFF_DATA 3
#define SLLIN_SAMPLES_PER_CHAR 10
-#define SLLIN_CHARS_TO_TIMEOUT 12
+#define SLLIN_CHARS_TO_TIMEOUT 24
enum slstate {
SLSTATE_IDLE = 0,
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 */
+ canid_t frame_fl; /* LIN frame flags. Passed from userspace as
+ canid_t data type */
u8 data[8]; /* LIN frame data payload */
};
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 */
+ char header_received;/* In Slave mode, set when header was already
+ received */
unsigned long flags; /* Flag values/ mode etc */
#define SLF_INUSE 0 /* Channel in use */
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*/
+ struct sk_buff *tx_req_skb; /* Socket buffer with CAN frame
+ received from network stack*/
- struct sllin_conf_entry linfr_cache[LIN_ID_MAX + 1]; /* List with configurations for
- each of 0 to LIN_ID_MAX LIN IDs */
+ /* 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;
};
/**
- * sltty_change_speed() -- Change baudrate of Serial device belonging to particular @tty
+ * 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
+ * @speed: Integer value of new speed. It is possible to
* assign non-standard values, i.e. those which
* are not defined in termbits.h.
*/
mutex_lock(&tty->termios_mutex);
old_termios = *(tty->termios);
- cflag = tty->termios->c_cflag;
+
+ cflag = CS8 | CREAD | CLOCAL | HUPCL;
cflag &= ~(CBAUD | CIBAUD);
cflag |= BOTHER;
tty->termios->c_cflag = cflag;
+ tty->termios->c_oflag = 0;
+ tty->termios->c_lflag = 0;
+
+ /* Enable interrupt when UART-Break or Framing error received */
+ tty->termios->c_iflag = BRKINT | INPCK;
tty_encode_baud_rate(tty, speed, speed);
return 0;
}
-
/* Send one can_frame to the network layer */
static void sllin_send_canfr(struct sllin *sl, canid_t id, char *data, int len)
{
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
+ * sll_bump() -- Send data of received LIN frame (existing in sl->rx_buff)
+ * as CAN frame
*
* @sl:
*/
sl->rx_cnt - SLLIN_BUFF_DATA - 1); /* without checksum */
}
+static void sll_send_rtr(struct sllin *sl)
+{
+ sllin_send_canfr(sl, (sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK) |
+ CAN_RTR_FLAG, NULL, 0);
+}
+
/*
* Called by the driver when there's room for more data. If we have
* more packets to send, we send them here.
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);
+ 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",
+ pr_debug("sllin: sllin_write_wakeup sent %d, "
+ "remains %d, waiting\n",
sl->tx_cnt, sl->tx_lim - sl->tx_cnt);
return;
}
const unsigned char *cp, char *fp, int count)
{
struct sllin *sl = (struct sllin *) tty->disc_data;
-
- pr_debug("sllin: sllin_receive_buf invoked\n");
+ pr_debug("sllin: sllin_receive_buf invoked, count = %u\n", count);
if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
return;
/* Read the characters out of the buffer */
while (count--) {
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;
+
+ if (sl->lin_master == true) { /* Report error */
+ set_bit(SLF_ERROR, &sl->flags);
+ wake_up(&sl->kwt_wq);
+ return;
+ } else { /* Received Break */
+ sl->rx_cnt = 0;
+ sl->rx_expect = SLLIN_BUFF_ID + 1;
+ sl->header_received = false;
+ return;
+ }
}
if (sl->rx_cnt < SLLIN_BUFF_LEN) {
#ifndef BREAK_BY_BAUD
- /* We didn't receive Break character */
+ /* We didn't receive Break character -- fake it! */
if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
+ pr_debug("sllin: LIN_RX[%d]: 0x00\n", sl->rx_cnt);
sl->rx_buff[sl->rx_cnt++] = 0x00;
}
#endif
}
}
- 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);
+ if (sl->lin_master == true) {
+ if (sl->rx_cnt >= sl->rx_expect) { /* Probably whole frame was received */
+ 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);
+ }
+ } else { /* LIN slave */
+ int lin_id;
+ struct sllin_conf_entry *sce;
+
+ pr_debug("sllin: rx_cnt = %u; header_received = %u\n",
+ sl->rx_cnt, sl->header_received);
+
+ /* Whole header was received */
+ if ((sl->rx_cnt >= (SLLIN_BUFF_ID + 1)) &&
+ (sl->header_received == false))
+ {
+ lin_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
+ sce = &sl->linfr_cache[lin_id];
+
+ /* Is the length of data set in frame cache? */
+ if (sce->frame_fl & LIN_LOC_SLAVE_CACHE)
+ sl->rx_expect += sce->dlc;
+ else
+ sl->rx_expect += 2; /* 1 data byte + checksum */
+
+ sl->header_received = true;
+ sll_send_rtr(sl);
+ }
+
+ /* Probably whole frame was received */
+ if ((sl->rx_cnt >= sl->rx_expect) && (sl->rx_cnt > SLLIN_BUFF_DATA)) {
+ sll_bump(sl);
+ pr_debug("sllin: Received LIN header & LIN response. "
+ "rx_cnt = %u, rx_expect = %u\n", sl->rx_cnt,
+ sl->rx_expect);
+
+ /* Prepare for reception of new header */
+ sl->rx_cnt = 0;
+ sl->rx_expect = SLLIN_BUFF_ID + 1;
+ sl->header_received = false;
+ }
}
}
* sllin message helper routines
*****************************************/
/**
- * sllin_report_error() -- Report an error by sending CAN frame \
+ * sllin_report_error() -- Report an error by sending CAN frame
* with particular error flag set in can_id
*
* @sl:
*/
void sllin_report_error(struct sllin *sl, int err)
{
- sllin_send_canfr(sl, 0 | CAN_EFF_FLAG |
+ switch (err) {
+ case LIN_ERR_CHECKSUM:
+ sl->dev->stats.rx_crc_errors++;
+ break;
+
+ case LIN_ERR_RX_TIMEOUT:
+ sl->dev->stats.rx_errors++;
+ break;
+
+ case LIN_ERR_FRAMING:
+ sl->dev->stats.rx_frame_errors++;
+ break;
+ }
+
+ sllin_send_canfr(sl, 0 | CAN_EFF_FLAG |
(err & ~LIN_ID_MASK), NULL, 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.
} else {
i = SLLIN_BUFF_DATA;
}
-
+
for (; i < length; i++) {
csum += data[i];
if (csum > 255)
return 0;
}
+static void sllin_reset_buffs(struct sllin *sl)
+{
+ 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;
+}
int sllin_send_tx_buff(struct sllin *sl)
{
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
return -1;
}
-
+
remains -= res;
sl->tx_cnt += res;
}
sl->rx_expect = SLLIN_BUFF_BREAK + 1;
sl->lin_state = SLSTATE_BREAK_SENT;
- /* Do the break ourselves; Inspired by
+ /* 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);
+ /* 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);
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;
int ext_chcks_fl;
int lin_dlc;
unsigned char rec_chcksm = sl->rx_buff[sl->rx_cnt - 1];
- struct sllin_conf_entry *scf;
+ struct sllin_conf_entry *scf;
- actual_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
+ 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) !=
+ if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1, ext_chcks_fl) !=
rec_chcksm) {
/* Type of checksum is configured for particular frame */
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_ERROR, &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");
+ pr_debug("sllin: sllin_kthread RXEVENT\n");
+ }
+
+ if (test_and_clear_bit(SLF_ERROR, &sl->flags)) {
+ unsigned long usleep_range_min;
+ unsigned long usleep_range_max;
+ hrtimer_cancel(&sl->rx_timer);
+ pr_debug("sllin: sllin_kthread ERROR\n");
+
+ if (sl->lin_state != SLSTATE_IDLE)
+ sllin_report_error(sl, LIN_ERR_FRAMING);
+
+ usleep_range_min = (1000000l * SLLIN_SAMPLES_PER_CHAR * 10) /
+ sl->lin_baud;
+ usleep_range_max = usleep_range_min + 50;
+ usleep_range(usleep_range_min, usleep_range_max);
+ sllin_reset_buffs(sl);
+ sl->lin_state = SLSTATE_IDLE;
}
if (test_and_clear_bit(SLF_TXEVENT, &sl->flags)) {
- pr_debug("sllin: sllin_kthread TXEVENT \n");
+ 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;
-
+ pr_debug("sllin: sllin_kthread TMOUTEVENT\n");
+ sllin_reset_buffs(sl);
+
sl->lin_state = SLSTATE_IDLE;
}
cf = (struct can_frame *)sl->tx_req_skb->data;
- /* SFF RTR CAN frame -> LIN header */
+ /* 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)
+ 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;
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:
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_WAIT;
/* If we don't receive anything, timer will "unblock" us */
- hrtimer_start(&sl->rx_timer,
+ hrtimer_start(&sl->rx_timer,
ktime_add(ktime_get(), sl->rx_timer_timeout),
HRTIMER_MODE_ABS);
goto slstate_response_wait;
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,
+ hrtimer_cancel(&sl->rx_timer);
+ pr_debug("sllin: received LIN response in a CAN frame.\n");
+ if (sllin_setup_msg(sl, SLLIN_STPMSG_RESPONLY,
cf->can_id & LIN_ID_MASK,
cf->data, cf->can_dlc) != -1) {
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);
}
}
+ /* 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);
- //FIXME tx_stat.err++
} else {
- // send CAN non-RTR frame with data
+ /* 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
+ 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
+
+ hrtimer_cancel(&sl->rx_timer);
+ 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->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);
if (!test_bit(SLF_INUSE, &sl->flags)) {
/* Perform the low-level SLLIN initialization. */
- sl->lin_master = true;
+ sl->lin_master = master;
+#ifdef DEBUG
+ if (master)
+ pr_debug("sllin: Configured as MASTER\n");
+ else
+ pr_debug("sllin: Configured as SLAVE\n");
+#endif
- 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;
+ sllin_reset_buffs(sl);
- sl->lin_baud = 19200;
+ sl->lin_baud = (baudrate == 0) ? LIN_DEFAULT_BAUDRATE : baudrate;
+ pr_debug("sllin: Baudrate set to %u\n", sl->lin_baud);
sl->lin_state = SLSTATE_IDLE;
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);
-
+ (1000000000l / sl->lin_baud) *
+ SLLIN_SAMPLES_PER_CHAR * SLLIN_CHARS_TO_TIMEOUT);
+
set_bit(SLF_INUSE, &sl->flags);
init_waitqueue_head(&sl->kwt_wq);
/* Done. We have linked the TTY line to a channel. */
rtnl_unlock();
- tty->receive_room = SLLIN_BUFF_LEN * 40; /* 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;
projects / linux-lin.git / blobdiff