- Add a uart_rxready() and corresponding device-specific implementations

  that can be used to check whether receive data is ready, i.e. whether
  the subsequent call of uart_poll() should return a char, and unlike
  uart_poll() doesn't actually receive data.
- Remove the device-specific implementations of uart_poll() and implement
  uart_poll() in terms of uart_getc() and the newly added uart_rxready()
  in order to minimize code duplication.
- In sunkbd(4) take advantage of uart_rxready() and use it to implement
  the polled mode part of sunkbd_check() so we don't need to buffer a
  potentially read char in the softc.
- Fix some mis-indentation in sunkbd_read_char().

Discussed with:	marcel

5 files changed, 35 insertions, 35 deletions

diff --git a/sys/dev/uart/uart_cpu.h b/sys/dev/uart/uart_cpu.h
index a3f0dcb..b41ed50 100644
--- a/sys/dev/uart/uart_cpu.h
+++ b/sys/dev/uart/uart_cpu.h
@@ -41,7 +41,7 @@ struct uart_ops {
 	void (*init)(struct uart_bas *, int, int, int, int);
 	void (*term)(struct uart_bas *);
 	void (*putc)(struct uart_bas *, int);
-	int (*poll)(struct uart_bas *);
+	int (*rxready)(struct uart_bas *);
 	int (*getc)(struct uart_bas *, struct mtx *);
 };
 
@@ -137,12 +137,26 @@ uart_putc(struct uart_devinfo *di, int c)
 }
 
 static __inline int
+uart_rxready(struct uart_devinfo *di)
+{
+	int res;
+
+	uart_lock(di->hwmtx);
+	res = di->ops.rxready(&di->bas);
+	uart_unlock(di->hwmtx);
+	return (res);
+}
+
+static __inline int
 uart_poll(struct uart_devinfo *di)
 {
 	int res;
 
 	uart_lock(di->hwmtx);
-	res = di->ops.poll(&di->bas);
+	if (di->ops.rxready(&di->bas))
+		res = di->ops.getc(&di->bas, NULL);
+	else
+		res = -1;
 	uart_unlock(di->hwmtx);
 	return (res);
 }
diff --git a/sys/dev/uart/uart_dev_ns8250.c b/sys/dev/uart/uart_dev_ns8250.c
index ba16b55..4262f8d 100644
--- a/sys/dev/uart/uart_dev_ns8250.c
+++ b/sys/dev/uart/uart_dev_ns8250.c
@@ -217,7 +217,7 @@ static int ns8250_probe(struct uart_bas *bas);
 static void ns8250_init(struct uart_bas *bas, int, int, int, int);
 static void ns8250_term(struct uart_bas *bas);
 static void ns8250_putc(struct uart_bas *bas, int);
-static int ns8250_poll(struct uart_bas *bas);
+static int ns8250_rxready(struct uart_bas *bas);
 static int ns8250_getc(struct uart_bas *bas, struct mtx *);
 
 struct uart_ops uart_ns8250_ops = {
@@ -225,7 +225,7 @@ struct uart_ops uart_ns8250_ops = {
 	.init = ns8250_init,
 	.term = ns8250_term,
 	.putc = ns8250_putc,
-	.poll = ns8250_poll,
+	.rxready = ns8250_rxready,
 	.getc = ns8250_getc,
 };
 
@@ -299,12 +299,10 @@ ns8250_putc(struct uart_bas *bas, int c)
 }
 
 static int
-ns8250_poll(struct uart_bas *bas)
+ns8250_rxready(struct uart_bas *bas)
 {
 
-	if (uart_getreg(bas, REG_LSR) & LSR_RXRDY)
-		return (uart_getreg(bas, REG_DATA));
-	return (-1);
+	return ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) != 0 ? 1 : 0);
 }
 
 static int
diff --git a/sys/dev/uart/uart_dev_sab82532.c b/sys/dev/uart/uart_dev_sab82532.c
index 9ef0bd1..e10ae17 100644
--- a/sys/dev/uart/uart_dev_sab82532.c
+++ b/sys/dev/uart/uart_dev_sab82532.c
@@ -173,7 +173,7 @@ static int sab82532_probe(struct uart_bas *bas);
 static void sab82532_init(struct uart_bas *bas, int, int, int, int);
 static void sab82532_term(struct uart_bas *bas);
 static void sab82532_putc(struct uart_bas *bas, int);
-static int sab82532_poll(struct uart_bas *bas);
+static int sab82532_rxready(struct uart_bas *bas);
 static int sab82532_getc(struct uart_bas *bas, struct mtx *);
 
 struct uart_ops uart_sab82532_ops = {
@@ -181,7 +181,7 @@ struct uart_ops uart_sab82532_ops = {
 	.init = sab82532_init,
 	.term = sab82532_term,
 	.putc = sab82532_putc,
-	.poll = sab82532_poll,
+	.rxready = sab82532_rxready,
 	.getc = sab82532_getc,
 };
 
@@ -303,12 +303,10 @@ sab82532_putc(struct uart_bas *bas, int c)
 }
 
 static int
-sab82532_poll(struct uart_bas *bas)
+sab82532_rxready(struct uart_bas *bas)
 {
 
-	if (uart_getreg(bas, SAB_STAR) & SAB_STAR_RFNE)
-		return (sab82532_getc(bas, NULL));
-	return (-1);
+	return ((uart_getreg(bas, SAB_STAR) & SAB_STAR_RFNE) != 0 ? 1 : 0);
 }
 
 static int
diff --git a/sys/dev/uart/uart_dev_z8530.c b/sys/dev/uart/uart_dev_z8530.c
index 04ebc69..8509718 100644
--- a/sys/dev/uart/uart_dev_z8530.c
+++ b/sys/dev/uart/uart_dev_z8530.c
@@ -192,7 +192,7 @@ static int z8530_probe(struct uart_bas *bas);
 static void z8530_init(struct uart_bas *bas, int, int, int, int);
 static void z8530_term(struct uart_bas *bas);
 static void z8530_putc(struct uart_bas *bas, int);
-static int z8530_poll(struct uart_bas *bas);
+static int z8530_rxready(struct uart_bas *bas);
 static int z8530_getc(struct uart_bas *bas, struct mtx *);
 
 struct uart_ops uart_z8530_ops = {
@@ -200,7 +200,7 @@ struct uart_ops uart_z8530_ops = {
 	.init = z8530_init,
 	.term = z8530_term,
 	.putc = z8530_putc,
-	.poll = z8530_poll,
+	.rxready = z8530_rxready,
 	.getc = z8530_getc,
 };
 
@@ -235,12 +235,10 @@ z8530_putc(struct uart_bas *bas, int c)
 }
 
 static int
-z8530_poll(struct uart_bas *bas)
+z8530_rxready(struct uart_bas *bas)
 {
 
-	if (!(uart_getreg(bas, REG_CTRL) & BES_RXA))
-		return (-1);
-	return (uart_getreg(bas, REG_DATA));
+	return ((uart_getreg(bas, REG_CTRL) & BES_RXA) != 0 ? 1 : 0);
 }
 
 static int
diff --git a/sys/dev/uart/uart_kbd_sun.c b/sys/dev/uart/uart_kbd_sun.c
index 201761d..7395f9d 100644
--- a/sys/dev/uart/uart_kbd_sun.c
+++ b/sys/dev/uart/uart_kbd_sun.c
@@ -72,8 +72,6 @@ struct sunkbd_softc {
 	struct uart_softc	*sc_uart;
 	struct uart_devinfo	*sc_sysdev;
 
-	int			sc_checked_key;
-
 	struct callout		sc_repeat_callout;
 	int			sc_repeat_key;
 
@@ -403,7 +401,7 @@ sunkbd_check(keyboard_t *kbd)
 		return (TRUE);
 
 	if (sc->sc_polling != 0 && sc->sc_sysdev != NULL &&
-	    (sc->sc_checked_key = uart_poll(sc->sc_sysdev)) != -1)
+	    uart_rxready(sc->sc_sysdev))
 		return (TRUE);
 
 	return (FALSE);
@@ -441,12 +439,6 @@ sunkbd_read_char(keyboard_t *kbd, int wait)
 		goto process_code;
 	}
 
-	if (sc->sc_checked_key != -1) {
-		suncode = sc->sc_checked_key;
-		sc->sc_checked_key = -1;
-		goto process_code;
-	}
-
 	for (;;) {
  next_code:
 		if (!(sc->sc_flags & KPCOMPOSE) && (sc->sc_composed_char > 0)) {
@@ -472,7 +464,6 @@ sunkbd_read_char(keyboard_t *kbd, int wait)
 		case SKBD_RSP_IDLE:
 			break;
 		default:
-
  process_code:
 			++kbd->kb_count;
 			key = SKBD_KEY_CHAR(suncode);
@@ -565,10 +556,12 @@ sunkbd_read_char(keyboard_t *kbd, int wait)
 			if (key == 0x13) {	/* left alt (KP compose key) */
 #endif
 				if (release != 0) {
-				    if (sc->sc_flags & KPCOMPOSE) {
-					sc->sc_flags &= ~KPCOMPOSE;
-					if (sc->sc_composed_char > UCHAR_MAX)
-						sc->sc_composed_char = 0;
+					if (sc->sc_flags & KPCOMPOSE) {
+						sc->sc_flags &= ~KPCOMPOSE;
+						if (sc->sc_composed_char >
+						    UCHAR_MAX)
+							sc->sc_composed_char =
+							    0;
 					}
 				} else {
 					if (!(sc->sc_flags & KPCOMPOSE)) {
@@ -768,7 +761,6 @@ sunkbd_clear_state(keyboard_t *kbd)
 	struct sunkbd_softc *sc;
 
 	sc = (struct sunkbd_softc *)kbd;
-	sc->sc_checked_key = -1;
 	sc->sc_repeat_key = -1;
 	sc->sc_accents = 0;
 	sc->sc_composed_char = 0;