[PATCH v1] watchdog: meson: keep running if already active

[Philippe Boos]

If the watchdog is already running (e.g.: started by bootloader) then
the kernel driver should keep the watchdog active but the amlogic driver
turns it off.

Let the driver fix the clock rate then restart the watchdog if it was
previously active.

Reviewed-by: Jerome Brunet <jbrunet at baylibre.com>
Signed-off-by: Philippe Boos <pboos at baylibre.com>
---
 drivers/watchdog/meson_gxbb_wdt.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index 5a9ca10fbcfa..8c2c6f7f3bb5 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -146,6 +146,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct meson_gxbb_wdt *data;
 	int ret;
+	u32 regval;
 
 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
@@ -177,6 +178,8 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 	data->wdt_dev.timeout = DEFAULT_TIMEOUT;
 	watchdog_set_drvdata(&data->wdt_dev, data);
 
+	regval = readl(data->reg_base + GXBB_WDT_CTRL_REG);
+
 	/* Setup with 1ms timebase */
 	writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
 		GXBB_WDT_CTRL_EE_RESET |
@@ -186,6 +189,13 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 
 	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
 
+	if ((regval & GXBB_WDT_CTRL_EN) != 0) {
+		ret = meson_gxbb_wdt_start(&data->wdt_dev);
+		if (ret)
+			return ret;
+		set_bit(WDOG_HW_RUNNING, &data->wdt_dev.status);
+	}
+
 	watchdog_stop_on_reboot(&data->wdt_dev);
 	return devm_watchdog_register_device(dev, &data->wdt_dev);
 }
-- 
2.20.1