[PATCH 08/10] board: sl28: disable recovery watchdog

Michael Walle
2021-11-15T22:47:32Z

This board has an internal watchdog which supervises the board startup.
Although, the initial state of the watchdog is configurable, it is
enabled by default. In board_late_init(), which means almost everything
worked as expected, disable the watchdog.

Signed-off-by: Michael Walle <michael@walle.cc>
---
board/kontron/sl28/sl28.c | 29 +++++++++++++++++++++++++++++
doc/board/kontron/sl28.rst | 12 ++++++------
2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/board/kontron/sl28/sl28.c b/board/kontron/sl28/sl28.c
index e5c9f90c7a..9572502499 100644
--- a/board/kontron/sl28/sl28.c
+++ b/board/kontron/sl28/sl28.c
@@ -15,6 +15,7 @@
#include <asm/arch/soc.h>
#include <fsl_immap.h>
#include <netdev.h>
+#include <wdt.h>

#include <sl28cpld.h>
#include <fdtdec.h>
@@ -73,6 +74,34 @@ int checkboard(void)
return 0;
}

+static void stop_recovery_watchdog(void)
+{
+ struct udevice *dev;
+ int ret;
+
+ ret = uclass_get_device_by_driver(UCLASS_WDT,
+ DM_DRIVER_GET(sl28cpld_wdt), &dev);
+ if (!ret)
+ wdt_stop(dev);
+}
+
+int fsl_board_late_init(void)
+{
+ /*
+ * Usually, the after a board reset, the watchdog is enabled by
+ * default. This is to supervise the bootloader boot-up. Therefore,
+ * to prevent a watchdog reset if we don't actively kick it, we have
+ * to disable it.
+ *
+ * If the watchdog isn't enabled at reset (which is a configuration
+ * option) disabling it doesn't hurt either.
+ */
+ if (!CONFIG_IS_ENABLED(WATCHDOG_AUTOSTART))
+ stop_recovery_watchdog();
+
+ return 0;
+}
+
void detail_board_ddr_info(void)
{
print_ddr_info(0);
diff --git a/doc/board/kontron/sl28.rst b/doc/board/kontron/sl28.rst
index c2cdc5e424..04483e1e57 100644
--- a/doc/board/kontron/sl28.rst
+++ b/doc/board/kontron/sl28.rst
@@ -23,17 +23,17 @@ Copy u-boot.rom to a TFTP server.
Install the bootloader on the board
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

-Please note, this bootloader doesn't support the builtin watchdog (yet),
-therefore you have to disable it, see below. Otherwise you'll end up in
-the failsafe bootloader on every reset::
+To install the bootloader binary use the following command::

> tftp path/to/u-boot.rom
> sf probe 0
> sf update $fileaddr 0x210000 $filesize

-The board is fully failsafe, you can't break anything. But because you've
-disabled the builtin watchdog you might have to manually enter failsafe
-mode by asserting the ``FORCE_RECOV#`` line during board reset.
+The board is fully failsafe, you can't break anything. If builtin watchdog
+is enabled, you'll automatically end up in the failsafe bootloader if
+something goes wrong. If the watchdog is disabled, you have to manually
+enter failsafe mode by asserting the ``FORCE_RECOV#`` line during board
+reset.

Update image
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--
2.30.2