Revert previous commit. It breaks the serial console on my rpi4.

2 files changed, 21 insertions, 83 deletions

diff --git a/sys/dev/ic/pluart.c b/sys/dev/ic/pluart.c
index 31da89eaef1..8a2b512eaeb 100644
--- a/sys/dev/ic/pluart.c
+++ b/sys/dev/ic/pluart.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pluart.c,v 1.8 2022/03/11 06:45:22 anton Exp $	*/
+/*	$OpenBSD: pluart.c,v 1.9 2022/03/13 21:17:52 kettenis Exp $	*/
 /*
  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
  * Copyright (c) 2005 Dale Rahn <drahn@dalerahn.com>
@@ -99,13 +99,6 @@
 #define UART_CR_CTSE		(1 << 14)	/* CTS hardware flow control enable */
 #define UART_CR_RTSE		(1 << 15)	/* RTS hardware flow control enable */
 #define UART_IFLS		0x34		/* Interrupt FIFO level select register */
-#define UART_IFLS_RX_SHIFT	3		/* RX level in bits [5:3] */
-#define UART_IFLS_TX_SHIFT	0		/* TX level in bits [2:0] */
-#define UART_IFLS_1_8		0		/* FIFO 1/8 full */
-#define UART_IFLS_1_4		1		/* FIFO 1/4 full */
-#define UART_IFLS_1_2		2		/* FIFO 1/2 full */
-#define UART_IFLS_3_4		3		/* FIFO 3/4 full */
-#define UART_IFLS_7_8		4		/* FIFO 7/8 full */
 #define UART_IMSC		0x38		/* Interrupt mask set/clear register */
 #define UART_IMSC_RIMIM		(1 << 0)
 #define UART_IMSC_CTSMIM	(1 << 1)
@@ -122,16 +115,8 @@
 #define UART_MIS		0x40		/* Masked interrupt status register */
 #define UART_ICR		0x44		/* Interrupt clear register */
 #define UART_DMACR		0x48		/* DMA control register */
-#define UART_PID0		0xfe0		/* Peripheral identification register 0 */
-#define UART_PID1		0xfe4		/* Peripheral identification register 1 */
-#define UART_PID2		0xfe8		/* Peripheral identification register 2 */
-#define UART_PID2_REV(x)	(((x) & 0xf0) >> 4)
-#define UART_PID3		0xfec		/* Peripheral identification register 3 */
 #define UART_SPACE		0x100
 
-#define UART_FIFO_SIZE		16
-#define UART_FIFO_SIZE_R3	32
-
 void pluartcnprobe(struct consdev *cp);
 void pluartcninit(struct consdev *cp);
 int pluartcngetc(dev_t dev);
@@ -165,31 +150,7 @@ struct cdevsw pluartdev =
 void
 pluart_attach_common(struct pluart_softc *sc, int console)
 {
-	int fifolen, maj;
-	int lcr;
-
-	if ((sc->sc_hwflags & COM_HW_SBSA) == 0) {
-		int rev;
-
-		rev = UART_PID2_REV(bus_space_read_4(sc->sc_iot, sc->sc_ioh,
-		    UART_PID2));
-		if (rev < 3)
-			fifolen = UART_FIFO_SIZE;
-		else
-			fifolen = UART_FIFO_SIZE_R3;
-		printf(": rev %d, %d byte fifo\n", rev, fifolen);
-	} else {
-		/*
-		 * The SBSA UART is PL011 r1p5 compliant which implies revision
-		 * 3 with a 32 byte FIFO. However, we cannot expect to configure
-		 * RX/TX interrupt levels using the UARTIFLS register making it
-		 * impossible to make assumptions about the number of available
-		 * bytes in the FIFO. Therefore disable FIFO support for such
-		 * devices.
-		 */
-		fifolen = 0;
-		printf("\n");
-	}
+	int maj;
 
 	if (console) {
 		/* Locate the major number. */
@@ -198,7 +159,7 @@ pluart_attach_common(struct pluart_softc *sc, int console)
 				break;
 		cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
 
-		printf("%s: console\n", sc->sc_dev.dv_xname);
+		printf(": console");
 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
 	}
 
@@ -210,20 +171,13 @@ pluart_attach_common(struct pluart_softc *sc, int console)
 		panic("%s: can't establish soft interrupt.",
 		    sc->sc_dev.dv_xname);
 
-	if (fifolen > 0) {
-		bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IFLS,
-		    (UART_IFLS_3_4 << UART_IFLS_RX_SHIFT) |
-		    (UART_IFLS_1_4 << UART_IFLS_TX_SHIFT));
-	}
-	sc->sc_imsc = UART_IMSC_RXIM | UART_IMSC_RTIM | UART_IMSC_TXIM;
-	bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IMSC, sc->sc_imsc);
+	bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IMSC, (UART_IMSC_RXIM | UART_IMSC_TXIM));
 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_ICR, 0x7ff);
-	lcr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, UART_LCR_H);
-	if (fifolen > 0)
-		lcr |= UART_LCR_H_FEN;
-	else
-		lcr &= ~UART_LCR_H_FEN;
-	bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_LCR_H, lcr);
+	bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_LCR_H,
+	    bus_space_read_4(sc->sc_iot, sc->sc_ioh, UART_LCR_H) &
+	    ~UART_LCR_H_FEN);
+
+	printf("\n");
 }
 
 int
@@ -243,26 +197,19 @@ pluart_intr(void *arg)
 	if (sc->sc_tty == NULL)
 		return 0;
 
-	if (!ISSET(is, UART_IMSC_RXIM) && !ISSET(is, UART_IMSC_RTIM) &&
-	    !ISSET(is, UART_IMSC_TXIM))
+	if (!ISSET(is, UART_IMSC_RXIM) && !ISSET(is, UART_IMSC_TXIM))
 		return 0;
 
-	if (ISSET(is, UART_IMSC_TXIM)) {
-		/* Disable transmit interrupt. */
-		bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IMSC,
-		    sc->sc_imsc & ~UART_IMSC_TXIM);
-
-		if (ISSET(tp->t_state, TS_BUSY)) {
-			CLR(tp->t_state, TS_BUSY | TS_FLUSH);
-			if (sc->sc_halt > 0)
-				wakeup(&tp->t_outq);
-			(*linesw[tp->t_line].l_start)(tp);
-		}
+	if (ISSET(is, UART_IMSC_TXIM) && ISSET(tp->t_state, TS_BUSY)) {
+		CLR(tp->t_state, TS_BUSY | TS_FLUSH);
+		if (sc->sc_halt > 0)
+			wakeup(&tp->t_outq);
+		(*linesw[tp->t_line].l_start)(tp);
 	}
 
 	p = sc->sc_ibufp;
 
-	while (!ISSET(bus_space_read_4(iot, ioh, UART_FR), UART_FR_RXFE)) {
+	while (ISSET(bus_space_read_4(iot, ioh, UART_FR), UART_FR_RXFF)) {
 		c = bus_space_read_2(iot, ioh, UART_DR);
 		if (c & UART_DR_BE) {
 #ifdef DDB
@@ -378,6 +325,7 @@ pluart_start(struct tty *tp)
 	struct pluart_softc *sc = pluart_cd.cd_devs[DEVUNIT(tp->t_dev)];
 	bus_space_tag_t iot = sc->sc_iot;
 	bus_space_handle_t ioh = sc->sc_ioh;
+	u_int16_t fr;
 	int s;
 
 	s = spltty();
@@ -388,19 +336,11 @@ pluart_start(struct tty *tp)
 		goto out;
 	SET(tp->t_state, TS_BUSY);
 
-	/* Enable transmit interrupt. */
-	bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IMSC, sc->sc_imsc);
-
-	while (tp->t_outq.c_cc > 0) {
-		uint16_t fr;
-
-		fr = bus_space_read_4(iot, ioh, UART_FR);
-		if (ISSET(fr, UART_FR_TXFF))
-			break;
-
+	fr = bus_space_read_4(iot, ioh, UART_FR);
+	while (tp->t_outq.c_cc != 0 && ISSET(fr, UART_FR_TXFE)) {
 		bus_space_write_4(iot, ioh, UART_DR, getc(&tp->t_outq));
+		fr = bus_space_read_4(iot, ioh, UART_FR);
 	}
-
 out:
 	splx(s);
 }
diff --git a/sys/dev/ic/pluartvar.h b/sys/dev/ic/pluartvar.h
index 847cf9401c7..6fff43b249f 100644
--- a/sys/dev/ic/pluartvar.h
+++ b/sys/dev/ic/pluartvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pluartvar.h,v 1.2 2022/03/11 06:45:22 anton Exp $	*/
+/*	$OpenBSD: pluartvar.h,v 1.3 2022/03/13 21:17:52 kettenis Exp $	*/
 /*
  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
  * Copyright (c) 2005 Dale Rahn <drahn@dalerahn.com>
@@ -38,7 +38,6 @@ struct pluart_softc {
 #define COM_HW_FIFO     0x02
 #define COM_HW_SIR      0x20
 #define COM_HW_CONSOLE  0x40
-#define COM_HW_SBSA	0x80
 	u_int8_t	sc_swflags;
 #define COM_SW_SOFTCAR  0x01
 #define COM_SW_CLOCAL   0x02
@@ -46,7 +45,6 @@ struct pluart_softc {
 #define COM_SW_MDMBUF   0x08
 #define COM_SW_PPS      0x10
 	int		sc_fifolen;
-	int		sc_imsc;
 
 	u_int8_t	sc_initialize;
 	u_int8_t	sc_cua;