From 477daab60643cc5c7efcd5b1e1ea02d193135246 Mon Sep 17 00:00:00 2001 From: Xingyu Chen Date: Sun, 29 Sep 2019 18:53:49 +0800 Subject: [PATCH] watchdog: meson: Fix the wrong value of left time [ Upstream commit 2c77734642d52448aca673e889b39f981110828b ] The left time value is wrong when we get it by sysfs. The left time value should be equal to preset timeout value minus elapsed time value. According to the Meson-GXB/GXL datasheets which can be found at [0], the timeout value is saved to BIT[0-15] of the WATCHDOG_TCNT, and elapsed time value is saved to BIT[16-31] of the WATCHDOG_TCNT. [0]: http://linux-meson.com Fixes: 683fa50f0e18 ("watchdog: Add Meson GXBB Watchdog Driver") Signed-off-by: Xingyu Chen Acked-by: Neil Armstrong Reviewed-by: Kevin Hilman Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin --- drivers/watchdog/meson_gxbb_wdt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c index 69a5a57f1446..61297a6ab43a 100644 --- a/drivers/watchdog/meson_gxbb_wdt.c +++ b/drivers/watchdog/meson_gxbb_wdt.c @@ -137,8 +137,8 @@ static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev) reg = readl(data->reg_base + GXBB_WDT_TCNT_REG); - return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT) - - (reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000; + return ((reg & GXBB_WDT_TCNT_SETUP_MASK) - + (reg >> GXBB_WDT_TCNT_CNT_SHIFT)) / 1000; } static const struct watchdog_ops meson_gxbb_wdt_ops = {