[PATCH 1/2] driver/aspeed-wdt: fix pretimeout for counting down logic

[Heyi Guo <guoheyi@linux.alibaba.com>]

Aspeed watchdog uses counting down logic, so the value set to register
should be the value of subtracting pretimeout from total timeout.

Fixes: 9ec0b7e06835 ("watchdog: aspeed: Enable pre-timeout interrupt")

Signed-off-by: Heyi Guo <guoheyi@linux.alibaba.com>

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Andrew Jeffery <andrew@codeconstruct.com.au>
Cc: Eddie James <eajames@linux.ibm.com>
---
 drivers/watchdog/aspeed_wdt.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index b4773a6aaf8c..520d8aba12a5 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -187,6 +187,13 @@ static int aspeed_wdt_set_pretimeout(struct watchdog_device *wdd,
 	u32 actual = pretimeout * WDT_RATE_1MHZ;
 	u32 s = wdt->cfg->irq_shift;
 	u32 m = wdt->cfg->irq_mask;
+	u32 reload = readl(wdt->base + WDT_RELOAD_VALUE);
+
+	if (actual >= reload)
+		return -EINVAL;
+
+	/* watchdog timer is counting down */
+	actual = reload - actual;
 
 	wdd->pretimeout = pretimeout;
 	wdt->ctrl &= ~m;
-- 
2.43.0