[U-Boot] [PATCH 07/13 v3] arm: at91: Enable watchdog support

[Stefan Roese <sr@denx.de>]

This patch enables and starts the watchdog on the AT91 platform if
configured. The WD timeout value is read in the AT91 WD device driver
from the DT, using the "timeout-sec" DT property. If not provided in
the DT, the default value of 2 seconds is used.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Andreas Bießmann <andreas@biessmann.org>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
---
v3:
- Move WDT struct and macros into arch header so that it can be used
  by the arch code to start the driver (timeout value)
- This change now enables the use of the "timeout-sec" DT property
  to specifiy a board specific WD timeout value

v2:
- Remove #ifdef to enable compilation also in SPL version

 arch/arm/mach-at91/clock.c                 | 48 ++++++++++++++++++++++
 arch/arm/mach-at91/include/mach/at91_wdt.h | 10 +++++
 drivers/watchdog/at91sam9_wdt.c            | 10 -----
 3 files changed, 58 insertions(+), 10 deletions(-)

diff --git a/arch/arm/mach-at91/clock.c b/arch/arm/mach-at91/clock.c
index 64cbc3d1ed..1d3df2c09d 100644
--- a/arch/arm/mach-at91/clock.c
+++ b/arch/arm/mach-at91/clock.c
@@ -5,12 +5,17 @@
  */
 
 #include <common.h>
+#include <dm.h>
+#include <wdt.h>
 #include <asm/io.h>
 #include <asm/arch/hardware.h>
 #include <asm/arch/at91_pmc.h>
+#include <asm/arch/at91_wdt.h>
 
 #define EN_UPLL_TIMEOUT		500
 
+static struct udevice *watchdog_dev __attribute__((section(".data"))) = NULL;
+
 void at91_periph_clk_enable(int id)
 {
 	struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
@@ -118,3 +123,46 @@ 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_early_init_r(void)
+{
+	struct at91_wdt_priv *priv;
+
+	/* 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;
+		}
+	}
+
+	priv = dev_get_priv(watchdog_dev);
+	if (!priv) {
+		printf("Watchdog: priv not available!\n");
+		return 0;
+	}
+
+	wdt_start(watchdog_dev, priv->timeout * 1000, 0);
+	printf("Watchdog: Started\n");
+
+	return 0;
+}
diff --git a/arch/arm/mach-at91/include/mach/at91_wdt.h b/arch/arm/mach-at91/include/mach/at91_wdt.h
index cd2272367b..c977b090c8 100644
--- a/arch/arm/mach-at91/include/mach/at91_wdt.h
+++ b/arch/arm/mach-at91/include/mach/at91_wdt.h
@@ -43,4 +43,14 @@ typedef struct at91_wdt {
 #define AT91_WDT_MR_WDDBGHLT		0x10000000
 #define AT91_WDT_MR_WDIDLEHLT		0x20000000
 
+/* Hardware timeout in seconds */
+#define WDT_MAX_TIMEOUT		16
+#define WDT_DEFAULT_TIMEOUT	2
+
+struct at91_wdt_priv {
+	void __iomem *regs;
+	u32 regval;
+	u32 timeout;
+};
+
 #endif
diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
index 1c71778bdc..793425c8d2 100644
--- a/drivers/watchdog/at91sam9_wdt.c
+++ b/drivers/watchdog/at91sam9_wdt.c
@@ -31,16 +31,6 @@ DECLARE_GLOBAL_DATA_PTR;
  */
 #define WDT_SEC2TICKS(s)	(((s) << 8) - 1)
 
-/* Hardware timeout in seconds */
-#define WDT_MAX_TIMEOUT		16
-#define WDT_DEFAULT_TIMEOUT	2
-
-struct at91_wdt_priv {
-	void __iomem *regs;
-	u32 regval;
-	u32 timeout;
-};
-
 /*
  * Set the watchdog time interval in 1/256Hz (write-once)
  * Counter is 12 bit.
-- 
2.21.0