[src/trunk]: src/sys/dev/fdt Deactivate the watchdog timer during attach.

[aymeric <aymeric%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/390d93d608b1
branches:  trunk
changeset: 445424:390d93d608b1
user:      aymeric <aymeric%NetBSD.org@localhost>
date:      Sun Oct 28 15:06:10 2018 +0000

description:
Deactivate the watchdog timer during attach.

Recent u-boot starts up the watchdog timer, and we don't detect this so
e.g. my DE0 nanosoc reboots after about 20 seconds. Applying a reset to
the watchdog circuit is the only way to stop it according to the
documentation.

diffstat:

 sys/dev/fdt/dwcwdt_fdt.c |  8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diffs (29 lines):

diff -r a9e9e85a9ef1 -r 390d93d608b1 sys/dev/fdt/dwcwdt_fdt.c
--- a/sys/dev/fdt/dwcwdt_fdt.c  Sun Oct 28 15:00:19 2018 +0000
+++ b/sys/dev/fdt/dwcwdt_fdt.c  Sun Oct 28 15:06:10 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: dwcwdt_fdt.c,v 1.2 2018/10/14 18:28:55 aymeric Exp $ */
+/* $NetBSD: dwcwdt_fdt.c,v 1.3 2018/10/28 15:06:10 aymeric Exp $ */
 
 /*-
  * Copyright (c) 2018 Jared McNeill <jmcneill%invisible.ca@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: dwcwdt_fdt.c,v 1.2 2018/10/14 18:28:55 aymeric Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dwcwdt_fdt.c,v 1.3 2018/10/28 15:06:10 aymeric Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -191,6 +191,10 @@
                return;
        }
        rst = fdtbus_reset_get_index(phandle, 0);
+       if (rst && fdtbus_reset_assert(rst) != 0) {
+               aprint_error(": couldn't assert reset\n");
+               return;
+       }
        if (rst && fdtbus_reset_deassert(rst) != 0) {
                aprint_error(": couldn't de-assert reset\n");
                return;