board: sl28: disable recovery watchdog

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>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>

diff --git a/board/kontron/sl28/sl28.c b/board/kontron/sl28/sl28.c
index 9cde48e61eff7cb956eaddbbb72eb43d8ebe8b13..3c48a9141d0a8558103f2a51ac86bd0e90200205 100644 (file)
--- 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 c2cdc5e424110e798db8459569ef6c94c6c673e8..04483e1e573fcbc602b2a86d0301916bc71f24b0 100644 (file)
--- 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
 ------------