[U-Boot] [PATCH 06/12 v2] arm: at91: Enable watchdog support

[Stefan Roese]

This patch enables and starts the watchdog on the AT91 platform if
configured. Currently the WD timeout is configured to 16 seconds,
which is the longest value for this timer.

Signed-off-by: Stefan Roese <sr at denx.de>
Cc: Heiko Schocher <hs at denx.de>
Cc: Andreas Bießmann <andreas at biessmann.org>
Cc: Eugen Hristev <eugen.hristev at microchip.com>
---
v2:
- Remove #ifdef to enable compilation also in SPL version

 arch/arm/mach-at91/clock.c | 39 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/arch/arm/mach-at91/clock.c b/arch/arm/mach-at91/clock.c
index 64cbc3d1ed..e3513f3473 100644
--- a/arch/arm/mach-at91/clock.c
+++ b/arch/arm/mach-at91/clock.c
@@ -5,12 +5,16 @@
  */
 
 #include <common.h>
+#include <dm.h>
+#include <wdt.h>
 #include <asm/io.h>
 #include <asm/arch/hardware.h>
 #include <asm/arch/at91_pmc.h>
 
 #define EN_UPLL_TIMEOUT		500
 
+static struct udevice *watchdog_dev;
+
 void at91_periph_clk_enable(int id)
 {
 	struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
@@ -118,3 +122,38 @@ void at91_pllicpr_init(u32 icpr)
 
 	writel(icpr, &pmc->pllicpr);
 }
+
+/* Called by macro WATCHDOG_RESET */
+void watchdog_reset(void)
+{
+	static ulong next_reset;
+	ulong now;
+
+	if (!watchdog_dev)
+		return;
+
+	now = get_timer(0);
+
+	/* Do not reset the watchdog too often */
+	if (now > next_reset) {
+		next_reset = now + 1000;	/* reset every 1000ms */
+		wdt_reset(watchdog_dev);
+	}
+}
+
+int arch_misc_init(void)
+{
+	/* Init watchdog */
+	if (uclass_get_device_by_seq(UCLASS_WDT, 0, &watchdog_dev)) {
+		debug("Watchdog: Not found by seq!\n");
+		if (uclass_get_device(UCLASS_WDT, 0, &watchdog_dev)) {
+			puts("Watchdog: Not found!\n");
+			return 0;
+		}
+	}
+
+	wdt_start(watchdog_dev, 16000, 0);	/* 16 seconds is max */
+	printf("Watchdog: Started\n");
+
+	return 0;
+}
-- 
2.21.0