watchdog: orion: Remove unneeded atomic access

The RSTOUT register on the Armada 370 SoC variant is a dedicated register
(not shared across orthogonal subsystems) and so it's not needed to write
it atomically.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Tested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/orion_wdt.c

@@ -145,6 +145,7 @@ static int orion_wdt_ping(struct watchdog_device *wdt_dev)
 static int armada370_start(struct watchdog_device *wdt_dev)
 {
 	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+	u32 reg;
 
 	/* Set watchdog duration */
 	writel(dev->clk_rate * wdt_dev->timeout,
@@ -157,8 +158,10 @@ static int armada370_start(struct watchdog_device *wdt_dev)
 	atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
 						dev->data->wdt_enable_bit);
 
-	atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
-				      dev->data->rstout_enable_bit);
+	/* Enable reset on watchdog */
+	reg = readl(dev->rstout);
+	reg |= dev->data->rstout_enable_bit;
+	writel(reg, dev->rstout);
 	return 0;
 }