[PATCH] watchdog: bcm2835_wdt: Fix WDIOC_SETTIMEOUT handling

[Stefan Wahren]

Users report about the unexpected behavior for setting timeouts above
15 sec on Raspberry Pi. According to watchdog-api.rst the ioctl
WDIOC_SETTIMEOUT shouldn't fail because of hardware limitations.
But looking at the code shows that max_timeout based on the
register value PM_WDOG_TIME_SET, which is the maximum.

Since 664a39236e71 ("watchdog: Introduce hardware maximum heartbeat
in watchdog core") the watchdog core is able to handle this problem.

This fix has been tested with watchdog-test from selftests.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217374
Fixes: 664a39236e71 ("watchdog: Introduce hardware maximum heartbeat in watchdog core")
Signed-off-by: Stefan Wahren <wahrenst at gmx.net>
---
 drivers/watchdog/bcm2835_wdt.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c
index 7a855289ff5e..bb001c5d7f17 100644
--- a/drivers/watchdog/bcm2835_wdt.c
+++ b/drivers/watchdog/bcm2835_wdt.c
@@ -42,6 +42,7 @@

 #define SECS_TO_WDOG_TICKS(x) ((x) << 16)
 #define WDOG_TICKS_TO_SECS(x) ((x) >> 16)
+#define WDOG_TICKS_TO_MSECS(x) ((x) * 1000 >> 16)

 struct bcm2835_wdt {
 	void __iomem		*base;
@@ -140,7 +141,7 @@ static struct watchdog_device bcm2835_wdt_wdd = {
 	.info =		&bcm2835_wdt_info,
 	.ops =		&bcm2835_wdt_ops,
 	.min_timeout =	1,
-	.max_timeout =	WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
+	.max_hw_heartbeat_ms =	WDOG_TICKS_TO_MSECS(PM_WDOG_TIME_SET),
 	.timeout =	WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
 };

--
2.34.1