watchdog: Implement generic watchdog_reset() version

This patch tries to implement a generic watchdog_reset() function that
can be used by all boards that want to service the watchdog device in
U-Boot. This watchdog servicing is enabled via CONFIG_WATCHDOG.

Without this approach, new boards or platforms needed to implement a
board specific version of this functionality, mostly copy'ing the same
code over and over again into their board or platforms code base.

With this new generic function, the scattered other functions are now
removed to be replaced by the generic one. The new version also enables
the configuration of the watchdog timeout via the DT "timeout-sec"
property (if enabled via CONFIG_OF_CONTROL).

This patch also adds a new flag to the GD flags, to flag that the
watchdog is ready to use and adds the pointer to the watchdog device
to the GD. This enables us to remove the global "watchdog_dev"
variable, which was prone to cause problems because of its potentially
very early use in watchdog_reset(), even before the BSS is cleared.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Tom Rini <trini@konsulko.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Marek Behún" <marek.behun@nic.cz>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Maxim Sloyko <maxims@google.com>
Cc: Erik van Luijk <evanluijk@interact.nl>
Cc: Ryder Lee <ryder.lee@mediatek.com>
Cc: Weijie Gao <weijie.gao@mediatek.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: "Álvaro Fernández Rojas" <noltari@gmail.com>
Cc: Philippe Reynes <philippe.reynes@softathome.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com> (on zcu100)

2 files changed, 0 insertions, 65 deletions

diff --git a/board/CZ.NIC/turris_mox/turris_mox.c b/board/CZ.NIC/turris_mox/turris_mox.c
index 96cb9c7e5c6..8a4872343b6 100644
--- a/board/CZ.NIC/turris_mox/turris_mox.c
+++ b/board/CZ.NIC/turris_mox/turris_mox.c
@@ -119,41 +119,11 @@ int board_fix_fdt(void *blob)
 }
 #endif
 
-#ifdef CONFIG_WDT_ARMADA_37XX
-static struct udevice *watchdog_dev __attribute__((section(".data"))) = NULL;
-
-void watchdog_reset(void)
-{
-	static ulong next_reset;
-	ulong now;
-
-	if (!watchdog_dev)
-		return;
-
-	now = timer_get_us();
-
-	/* Do not reset the watchdog too often */
-	if (now > next_reset) {
-		wdt_reset(watchdog_dev);
-		next_reset = now + 100000;
-	}
-}
-#endif
-
 int board_init(void)
 {
 	/* address of boot parameters */
 	gd->bd->bi_boot_params = CONFIG_SYS_SDRAM_BASE + 0x100;
 
-#ifdef CONFIG_WDT_ARMADA_37XX
-	if (uclass_get_device(UCLASS_WDT, 0, &watchdog_dev)) {
-		printf("Cannot find Armada 3720 watchdog!\n");
-	} else {
-		printf("Enabling Armada 3720 watchdog (3 minutes timeout).\n");
-		wdt_start(watchdog_dev, 180000, 0);
-	}
-#endif
-
 	return 0;
 }
 
diff --git a/board/CZ.NIC/turris_omnia/turris_omnia.c b/board/CZ.NIC/turris_omnia/turris_omnia.c
index 0287f232834..4c08f810a24 100644
--- a/board/CZ.NIC/turris_omnia/turris_omnia.c
+++ b/board/CZ.NIC/turris_omnia/turris_omnia.c
@@ -364,25 +364,12 @@ static bool disable_mcu_watchdog(void)
 }
 #endif
 
-#if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_WDT_ORION)
-static struct udevice *watchdog_dev __attribute__((section(".data"))) = NULL;
-#endif
-
 int board_init(void)
 {
 	/* adress of boot parameters */
 	gd->bd->bi_boot_params = mvebu_sdram_bar(0) + 0x100;
 
 #ifndef CONFIG_SPL_BUILD
-# ifdef CONFIG_WDT_ORION
-	if (uclass_get_device(UCLASS_WDT, 0, &watchdog_dev)) {
-		puts("Cannot find Armada 385 watchdog!\n");
-	} else {
-		puts("Enabling Armada 385 watchdog.\n");
-		wdt_start(watchdog_dev, 120000, 0);
-	}
-# endif
-
 	if (disable_mcu_watchdog())
 		puts("Disabled MCU startup watchdog.\n");
 
@@ -392,28 +379,6 @@ int board_init(void)
 	return 0;
 }
 
-#ifdef CONFIG_WATCHDOG
-/* Called by macro WATCHDOG_RESET */
-void watchdog_reset(void)
-{
-# if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_WDT_ORION)
-	static ulong next_reset = 0;
-	ulong now;
-
-	if (!watchdog_dev)
-		return;
-
-	now = timer_get_us();
-
-	/* Do not reset the watchdog too often */
-	if (now > next_reset) {
-		wdt_reset(watchdog_dev);
-		next_reset = now + 1000;
-	}
-# endif
-}
-#endif
-
 int board_late_init(void)
 {
 #ifndef CONFIG_SPL_BUILD