From: =?UTF-8?q?Martin=20Hundeb=C3=B8ll?= <martin@geanix.com>
Date: Mon, 21 Oct 2019 10:08:38 +0200
Subject: rtc: pcf2127: handle boot-enabled watchdog feature
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Git-commit: 62409933b8d5afc9f09878608f3a38cf1b5467c2
Patch-mainline: v5.5-rc1
References: bsc#1185233

Linux should handle when the pcf2127 watchdog feature is enabled by the
bootloader. This is done by checking the watchdog timer value during
init, and set the WDOG_HW_RUNNING flag if the value differs from zero.

Signed-off-by: Martin Hundebøll <martin@geanix.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191021080838.2789-1-martin@geanix.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
---
 drivers/rtc/rtc-pcf2127.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 02b069caffd5..ba5baaca47be 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -417,6 +417,7 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
 			const char *name, bool has_nvmem)
 {
 	struct pcf2127 *pcf2127;
+	u32 wdd_timeout;
 	int ret = 0;
 
 	dev_dbg(dev, "%s\n", __func__);
@@ -459,7 +460,6 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
 	/*
 	 * Watchdog timer enabled and reset pin /RST activated when timed out.
 	 * Select 1Hz clock source for watchdog timer.
-	 * Timer is not started until WD_VAL is loaded with a valid value.
 	 * Note: Countdown timer disabled and not available.
 	 */
 	ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_WD_CTL,
@@ -475,6 +475,14 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
 		return ret;
 	}
 
+	/* Test if watchdog timer is started by bootloader */
+	ret = regmap_read(pcf2127->regmap, PCF2127_REG_WD_VAL, &wdd_timeout);
+	if (ret)
+		return ret;
+
+	if (wdd_timeout)
+		set_bit(WDOG_HW_RUNNING, &pcf2127->wdd.status);
+
 #ifdef CONFIG_WATCHDOG
 	ret = devm_watchdog_register_device(dev, &pcf2127->wdd);
 	if (ret)
-- 
2.26.2