/* Should be in include/linux/tty.h */
#define N_SLLIN 25
+#define N_SLLIN_SLAVE 26
/* -------------------------------- */
#ifdef SLLIN_LED_TRIGGER
static bool master = true;
static int baudrate; /* Use LIN_DEFAULT_BAUDRATE when not set */
+#ifndef BREAK_BY_BAUD
+static bool break_by_baud = false;
+#else /*BREAK_BY_BAUD*/
+static bool break_by_baud = true;
+#endif /*BREAK_BY_BAUD*/
module_param(master, bool, 0444);
MODULE_PARM_DESC(master, "LIN interface is Master device");
module_param(baudrate, int, 0444);
MODULE_PARM_DESC(baudrate, "Baudrate of LIN interface");
+module_param(break_by_baud, bool, 0444);
+MODULE_PARM_DESC(break_by_baud, "Break is sent by temporal baudrate switching");
static int maxdev = 10; /* MAX number of SLLIN channels;
This can be overridden with
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 */
+ bool lin_break_by_baud; /* send break character by baudrate switching */
int lin_baud; /* LIN baudrate */
int lin_state; /* state */
char id_to_send; /* there is ID to be sent */
}
}
-#ifndef BREAK_BY_BAUD
- /* We didn't receive Break character -- fake it! */
- if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
- netdev_dbg(sl->dev, "LIN_RX[%d]: 0x00\n", sl->rx_cnt);
- sl->rx_buff[sl->rx_cnt++] = 0x00;
+ if (!sl->lin_break_by_baud ) {
+ /* We didn't receive Break character -- fake it! */
+ if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
+ netdev_dbg(sl->dev, "LIN_RX[%d]: 0x00\n",
+ sl->rx_cnt);
+ sl->rx_buff[sl->rx_cnt++] = 0x00;
+ }
}
-#endif /* BREAK_BY_BAUD */
if (sl->rx_cnt < SLLIN_BUFF_LEN) {
netdev_dbg(sl->dev, "LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
smp_mb__after_atomic();
#endif
-#ifdef BREAK_BY_BAUD
- if (sl->lin_state != SLSTATE_BREAK_SENT)
+ if (sl->lin_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;
- 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)
}
-#ifdef BREAK_BY_BAUD
-static int sllin_send_break(struct sllin *sl)
+static int sllin_send_break_by_baud(struct sllin *sl)
{
struct tty_struct *tty = sl->tty;
unsigned long break_baud;
break_baud = ((sl->lin_baud * 2) / 3);
sltty_change_speed(tty, break_baud);
- if (tty != NULL && tty->ops != NULL && tty->ops->flush_buffer != NULL) {
+ if (tty->ops->flush_buffer != NULL) {
tty->ops->flush_buffer(tty);
} else {
netdev_dbg(sl->dev, "flush_buffer is not implemented.\n");
return 0;
}
-#else /* BREAK_BY_BAUD */
-static int sllin_send_break(struct sllin *sl)
+static int sllin_send_break_by_usleep(struct sllin *sl)
{
struct tty_struct *tty = sl->tty;
int retval;
return 0;
}
-#endif /* BREAK_BY_BAUD */
+static int sllin_send_break(struct sllin *sl)
+{
+ if (sl->lin_break_by_baud)
+ return sllin_send_break_by_baud(sl);
+ else
+ return sllin_send_break_by_usleep(sl);
+}
static enum hrtimer_restart sllin_rx_timeout_handler(struct hrtimer *hrtimer)
{
break;
case SLSTATE_BREAK_SENT:
-#ifdef BREAK_BY_BAUD
- if (sl->rx_cnt <= SLLIN_BUFF_BREAK)
- continue;
+ if (sl->lin_break_by_baud) {
+ if (sl->rx_cnt <= SLLIN_BUFF_BREAK)
+ continue;
- res = sltty_change_speed(tty, sl->lin_baud);
-#endif
+ sltty_change_speed(tty, sl->lin_baud);
+ }
sl->lin_state = SLSTATE_ID_SENT;
sllin_send_tx_buff(sl);
* Called in process context serialized from other ldisc calls.
*/
-static int sllin_open(struct tty_struct *tty)
+static int sllin_open_common(struct tty_struct *tty, bool setup_master)
{
struct sllin *sl;
int err;
if (!test_bit(SLF_INUSE, &sl->flags)) {
/* Perform the low-level SLLIN initialization. */
- sl->lin_master = master;
- if (master)
+ sl->lin_master = setup_master;
+ if (sl->lin_master)
pr_debug("sllin: Configured as MASTER\n");
else
pr_debug("sllin: Configured as SLAVE\n");
sl->lin_baud = (baudrate == 0) ? LIN_DEFAULT_BAUDRATE : baudrate;
pr_debug("sllin: Baudrate set to %u\n", sl->lin_baud);
+ sl->lin_break_by_baud = break_by_baud;
+
+ if (tty->ops->break_ctl == NULL && !sl->lin_break_by_baud) {
+ sl->lin_break_by_baud = true;
+ pr_notice ("sllin: break_ctl, switching to break_by_baud\n");
+ }
+
sl->lin_state = SLSTATE_IDLE;
hrtimer_init(&sl->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
return err;
}
+/*
+ * Open the high-level part of the SLLIN channel.
+ * This function is called by the TTY module when the
+ * SLLIN line discipline is called for. Because we are
+ * sure the tty line exists, we only have to link it to
+ * a free SLLIN channel...
+ *
+ * Called in process context serialized from other ldisc calls.
+ *
+ * This call variant preserves original functionality where
+ * slave/master can be selected by module parameter.
+ * Default is the master.
+ */
+
+static int sllin_open(struct tty_struct *tty)
+{
+ return sllin_open_common(tty, master);
+}
+
+/*
+ * Open the high-level part of the SLLIN channel.
+ * This function is called by the TTY module when the
+ * SLLIN line discipline is called for. Because we are
+ * sure the tty line exists, we only have to link it to
+ * a free SLLIN channel...
+ *
+ * Called in process context serialized from other ldisc calls.
+ *
+ * This call variant enforces slave/LIN device functionality.
+ */
+
+static int sllin_open_slave(struct tty_struct *tty)
+{
+ return sllin_open_common(tty, false);
+}
+
+
/*
* Close down a SLLIN channel.
* This means flushing out any pending queues, and then returning. This
.write_wakeup = sllin_write_wakeup,
};
+static struct tty_ldisc_ops sll_slave_ldisc = {
+ .owner = THIS_MODULE,
+ .magic = TTY_LDISC_MAGIC,
+ .name = "sllin-slave",
+ .open = sllin_open_slave,
+ .close = sllin_close,
+ .hangup = sllin_hangup,
+ .ioctl = sllin_ioctl,
+ .receive_buf = sllin_receive_buf,
+ .write_wakeup = sllin_write_wakeup,
+};
+
static int __init sllin_init(void)
{
int status;
if (status) {
pr_err("sllin: can't register line discipline\n");
kfree(sllin_devs);
+ } else {
+ status = tty_register_ldisc(N_SLLIN_SLAVE, &sll_slave_ldisc);
+ if (status) {
+ tty_unregister_ldisc(N_SLLIN);
+ pr_err("sllin: can't register slave 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
+
+ if (break_by_baud)
+ pr_debug("sllin: Break is generated by baud-rate change.");
+ else
+ pr_debug("sllin: Break is generated manually with tiny sleep.");
return status;
}
if (i)
pr_err("sllin: can't unregister ldisc (err %d)\n", i);
+ i = tty_unregister_ldisc(N_SLLIN_SLAVE);
+ if (i)
+ pr_err("sllin: can't unregister slave ldisc (err %d)\n", i);
+
+
#ifdef SLLIN_LED_TRIGGER
unregister_netdevice_notifier(&sllin_netdev_notifier);
#endif