Make sure we program the baud rate divisor register. Without this,

opening the tty corresponding to a non-console device will hang the
machine.

ok deraadt@

diff --git a/sys/arch/riscv64/dev/sfuart.c b/sys/arch/riscv64/dev/sfuart.c
index 31e649c..eb7bad9 100644 (file)
--- a/sys/arch/riscv64/dev/sfuart.c
+++ b/sys/arch/riscv64/dev/sfuart.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: sfuart.c,v 1.2 2021/06/13 09:19:14 kettenis Exp $     */
+/*     $OpenBSD: sfuart.c,v 1.3 2021/06/20 17:55:37 kettenis Exp $     */
 /*
  * Copyright (c) 2019 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -29,6 +29,7 @@
 
 #include <dev/ofw/fdt.h>
 #include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_clock.h>
 
 #define UART_TXDATA                    0x0000
 #define  UART_TXDATA_FULL              (1U << 31)
@@ -76,6 +77,8 @@ struct sfuart_softc {
        bus_space_tag_t         sc_iot;
        bus_space_handle_t      sc_ioh;
 
+       uint32_t                sc_frequency;
+
        struct soft_intrhand    *sc_si;
        void                    *sc_ih;
 
@@ -157,6 +160,7 @@ sfuart_attach(struct device *parent, struct device *self, void *aux)
                return;
        }
 
+       sc->sc_frequency = clock_get_frequency(faa->fa_node, NULL);
        if (faa->fa_node == stdout_node) {
                /* Locate the major number. */
                for (maj = 0; maj < nchrdev; maj++)
@@ -267,6 +271,7 @@ sfuart_param(struct tty *tp, struct termios *t)
 {
        struct sfuart_softc *sc = sfuart_sc(tp->t_dev);
        int ospeed = t->c_ospeed;
+       uint32_t div;
 
        /* Check requested parameters. */
        if (ospeed < 0 || (t->c_ispeed && t->c_ispeed != t->c_ospeed))
@@ -294,6 +299,11 @@ sfuart_param(struct tty *tp, struct termios *t)
                                return error;
                        }
                }
+
+               div = (sc->sc_frequency + ospeed / 2) / ospeed;
+               if (div < 16 || div > 65536)
+                       return EINVAL;
+               HWRITE4(sc, UART_DIV, div - 1);
        }
 
        tp->t_ispeed = t->c_ispeed;
@@ -365,7 +375,7 @@ sfuartopen(dev_t dev, int flag, int mode, struct proc *p)
                tp->t_lflag = TTYDEF_LFLAG;
                tp->t_ispeed = tp->t_ospeed =
                    sc->sc_conspeed ? sc->sc_conspeed : B115200;
-               
+
                s = spltty();
 
                sfuart_param(tp, &tp->t_termios);
@@ -460,7 +470,7 @@ sfuartread(dev_t dev, struct uio *uio, int flag)
 
        if (tp == NULL)
                return ENODEV;
-       
+
        return (*linesw[tp->t_line].l_read)(tp, uio, flag);
 }
 
@@ -471,7 +481,7 @@ sfuartwrite(dev_t dev, struct uio *uio, int flag)
 
        if (tp == NULL)
                return ENODEV;
-       
+
        return (*linesw[tp->t_line].l_write)(tp, uio, flag);
 }
 
@@ -577,7 +587,7 @@ int
 sfuartcngetc(dev_t dev)
 {
        uint32_t val;
-       
+
        do {
                val = bus_space_read_4(sfuartconsiot, sfuartconsioh, UART_RXDATA);
                if (val & UART_RXDATA_EMPTY)