Ejemplo n.º 1
0
/*
 * Slightly higher-level routines aware of buffering and flow control.
 */
static inline int
aju_writable(struct altera_jtag_uart_softc *sc)
{

	return ((aju_control_read(sc) &
	    ALTERA_JTAG_UART_CONTROL_WSPACE) != 0);
}
Ejemplo n.º 2
0
static void
aju_ac_callout(void *arg)
{
	struct altera_jtag_uart_softc *sc = arg;
	struct tty *tp = sc->ajus_ttyp;
	uint32_t v;

	tty_lock(tp);
	AJU_LOCK(sc);
	v = aju_control_read(sc);
	if (v & ALTERA_JTAG_UART_CONTROL_AC) {
		v &= ~ALTERA_JTAG_UART_CONTROL_AC;
		aju_control_write(sc, v);
		if (*sc->ajus_jtag_presentp == 0) {
			*sc->ajus_jtag_missedp = 0;
			*sc->ajus_jtag_presentp = 1;
			aju_handle_output(sc, tp);
		}
	} else if (*sc->ajus_jtag_presentp != 0) {
		(*sc->ajus_jtag_missedp)++;
		if (*sc->ajus_jtag_missedp >= AJU_JTAG_MAXMISS) {
			*sc->ajus_jtag_presentp = 0;
			aju_handle_output(sc, tp);
		}
	}
	callout_reset(&sc->ajus_ac_callout, AJU_AC_POLLINTERVAL,
	    aju_ac_callout, sc);
	AJU_UNLOCK(sc);
	tty_unlock(tp);
}
Ejemplo n.º 3
0
/*
 * Send output to the UART until either there's none left to send, or we run
 * out of room and need to await an interrupt so that we can start sending
 * again.
 *
 * XXXRW: It would be nice to query WSPACE at the beginning and write to the
 * FIFO in bugger chunks.
 */
static void
aju_handle_output(struct altera_jtag_uart_softc *sc, struct tty *tp)
{
	uint32_t v;
	uint8_t ch;

	tty_lock_assert(tp, MA_OWNED);
	AJU_LOCK_ASSERT(sc);

	AJU_UNLOCK(sc);
	while (ttydisc_getc_poll(tp) != 0) {
		AJU_LOCK(sc);
		v = aju_control_read(sc);
		if ((v & ALTERA_JTAG_UART_CONTROL_WSPACE) != 0) {
			AJU_UNLOCK(sc);
			if (ttydisc_getc(tp, &ch, sizeof(ch)) != sizeof(ch))
				panic("%s: ttydisc_getc", __func__);
			AJU_LOCK(sc);

			/*
			 * XXXRW: There is a slight race here in which we test
			 * for writability, drop the lock, get the character
			 * from the tty layer, re-acquire the lock, and then
			 * write.  It's possible for other code --
			 * specifically, the low-level console -- to have
			 * written in the mean time, which might mean that
			 * there is no longer space.  The BERI memory bus will
			 * cause this write to block, wedging the processor
			 * until space is available -- which could be a while
			 * if JTAG is not attached!
			 *
			 * The 'easy' fix is to drop the character if WSPACE
			 * has become unset.  Not sure what the 'hard' fix is.
			 */
			aju_data_write(sc, ch);
		} else {
			/*
			 * If JTAG is not present, then we will drop this
			 * character instead of perhaps scheduling an
			 * interrupt to let us know when there is buffer
			 * space.  Otherwise we might get a write interrupt
			 * later even though we aren't interested in sending
			 * anymore.  Loop to drain TTY-layer buffer.
			 */
			if (*sc->ajus_jtag_presentp == 0) {
				if (ttydisc_getc(tp, &ch, sizeof(ch)) !=
				    sizeof(ch))
					panic("%s: ttydisc_getc 2", __func__);
				AJU_UNLOCK(sc);
				continue;
			}
			if (sc->ajus_irq_res != NULL)
				aju_intr_writable_enable(sc);
			return;
		}
		AJU_UNLOCK(sc);
	}
	AJU_LOCK(sc);
	aju_intr_writable_disable(sc);
}
Ejemplo n.º 4
0
static void
aju_intr_disable(struct altera_jtag_uart_softc *sc)
{
	uint32_t v;

	AJU_LOCK_ASSERT(sc);

	v = aju_control_read(sc);
	v &= ~(ALTERA_JTAG_UART_CONTROL_RE | ALTERA_JTAG_UART_CONTROL_WE);
	aju_control_write(sc, v);
}
Ejemplo n.º 5
0
static void
aju_intr_writable_disable(struct altera_jtag_uart_softc *sc)
{
	uint32_t v;

	AJU_LOCK_ASSERT(sc);

	atomic_add_int(&aju_intr_writable_disabled, 1);
	v = aju_control_read(sc);
	v &= ~ALTERA_JTAG_UART_CONTROL_WE;
	aju_control_write(sc, v);
}
Ejemplo n.º 6
0
static void
aju_intr(void *arg)
{
	struct altera_jtag_uart_softc *sc = arg;
	struct tty *tp = sc->ajus_ttyp;
	uint32_t v;

	tty_lock(tp);
	AJU_LOCK(sc);
	v = aju_control_read(sc);
	if (v & ALTERA_JTAG_UART_CONTROL_RI)
		aju_handle_input(sc, tp);
	if (v & ALTERA_JTAG_UART_CONTROL_WI)
		aju_handle_output(sc, tp);
	AJU_UNLOCK(sc);
	tty_unlock(tp);
}
Ejemplo n.º 7
0
/*
 * Send output to the UART until either there's none left to send, or we run
 * out of room and need to await an interrupt so that we can start sending
 * again.
 *
 * XXXRW: It would be nice to query WSPACE at the beginning and write to the
 * FIFO in bugger chunks.
 */
static void
aju_handle_output(struct altera_jtag_uart_softc *sc, struct tty *tp)
{
	uint32_t v;
	uint8_t ch;

	tty_lock_assert(tp, MA_OWNED);
	AJU_LOCK_ASSERT(sc);

	AJU_UNLOCK(sc);
	while (ttydisc_getc_poll(tp) != 0) {
		AJU_LOCK(sc);
		v = aju_control_read(sc);
		if ((v & ALTERA_JTAG_UART_CONTROL_WSPACE) != 0) {
			AJU_UNLOCK(sc);
			if (ttydisc_getc(tp, &ch, sizeof(ch)) != sizeof(ch))
				panic("%s: ttydisc_getc", __func__);
			AJU_LOCK(sc);
			aju_data_write(sc, ch);
		} else {
			/*
			 * If JTAG is not present, then we will drop this
			 * character instead of perhaps scheduling an
			 * interrupt to let us know when there is buffer
			 * space.  Otherwise we might get a write interrupt
			 * later even though we aren't interested in sending
			 * anymore.  Loop to drain TTY-layer buffer.
			 */
			if (*sc->ajus_jtag_presentp == 0) {
				if (ttydisc_getc(tp, &ch, sizeof(ch)) !=
				    sizeof(ch))
					panic("%s: ttydisc_getc 2", __func__);
				AJU_UNLOCK(sc);
				continue;
			}
			if (sc->ajus_irq_res != NULL)
				aju_intr_writable_enable(sc);
			return;
		}
		AJU_UNLOCK(sc);
	}
	AJU_LOCK(sc);
	aju_intr_writable_disable(sc);
}
Ejemplo n.º 8
0
static void
aju_ac_callout(void *arg)
{
	struct altera_jtag_uart_softc *sc = arg;
	struct tty *tp = sc->ajus_ttyp;
	uint32_t v;

	tty_lock(tp);
	AJU_LOCK(sc);
	v = aju_control_read(sc);
	if (v & ALTERA_JTAG_UART_CONTROL_AC) {
		v &= ~ALTERA_JTAG_UART_CONTROL_AC;
		aju_control_write(sc, v);
		if (*sc->ajus_jtag_presentp == 0) {
			*sc->ajus_jtag_presentp = 1;
			atomic_add_int(&aju_jtag_appeared, 1);
			aju_handle_output(sc, tp);
		}

		/* Any hit eliminates all recent misses. */
		*sc->ajus_jtag_missedp = 0;
	} else if (*sc->ajus_jtag_presentp != 0) {
		/*
		 * If we've exceeded our tolerance for misses, mark JTAG as
		 * disconnected and drain output.  Otherwise, bump the miss
		 * counter.
		 */
		if (*sc->ajus_jtag_missedp > AJU_JTAG_MAXMISS) {
			*sc->ajus_jtag_presentp = 0;
			atomic_add_int(&aju_jtag_vanished, 1);
			aju_handle_output(sc, tp);
		} else
			(*sc->ajus_jtag_missedp)++;
	}
	callout_reset(&sc->ajus_ac_callout, AJU_AC_POLLINTERVAL,
	    aju_ac_callout, sc);
	AJU_UNLOCK(sc);
	tty_unlock(tp);
}