[PATCH 2/4] watchdog: introduce a u-boot,autostart property

[Rasmus Villemoes]

This is a companion to u-boot,noautostart. If one has a single
watchdog device that one does want to have auto-started, but several
others that one doesn't, the only way currently is to set the
CONFIG_WATCHDOG_AUTOSTART and then use the opt-out for the majority.

The main motivation for this is to add an autostarted watchdog device
to the sandbox (to test a fix) without having to set AUTOSTART in
sandbox_defconfig and add the noautostart property to the existing
devices. But it's also nice for symmetry, and the logic in
init_watchdog_dev() becomes simpler to read because we avoid all the
negations.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
---
 doc/device-tree-bindings/watchdog/common.txt |  9 +++++----
 drivers/watchdog/wdt-uclass.c                | 15 +++++++++------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/doc/device-tree-bindings/watchdog/common.txt b/doc/device-tree-bindings/watchdog/common.txt
index 9db6dd6146..d041fea234 100644
--- a/doc/device-tree-bindings/watchdog/common.txt
+++ b/doc/device-tree-bindings/watchdog/common.txt
@@ -6,7 +6,8 @@ Optional properties:
                 be used instead.
 - hw_margin_ms : Period used to reset the watchdog in ms
                  If this period is not defined, the default value is 1000.
-- u-boot,noautostart : Specify that this watchdog should not autostart
-                       When the config option WATCHDOG_AUTOSTART is set, all enabled
-                       watchdogs are started. This property allows specifying that this
-                       watchdog should NOT be started.
+- u-boot,noautostart :
+- u-boot,autostart : These (mutually exclusive) boolean properties can be used to control
+                     whether the watchdog is automatically started when probed. If neither
+                     are present, the behaviour is determined by the config option
+                     WATCHDOG_AUTOSTART.
diff --git a/drivers/watchdog/wdt-uclass.c b/drivers/watchdog/wdt-uclass.c
index dbf556467d..5b3ceaf641 100644
--- a/drivers/watchdog/wdt-uclass.c
+++ b/drivers/watchdog/wdt-uclass.c
@@ -36,8 +36,8 @@ struct wdt_priv {
 	ulong next_reset;
 	/* Whether watchdog_start() has been called on the device. */
 	bool running;
-	/* No autostart */
-	bool noautostart;
+	/* autostart */
+	bool autostart;
 };
 
 static void init_watchdog_dev(struct udevice *dev)
@@ -54,7 +54,7 @@ static void init_watchdog_dev(struct udevice *dev)
 			       dev->name);
 	}
 
-	if (!IS_ENABLED(CONFIG_WATCHDOG_AUTOSTART) || priv->noautostart) {
+	if (!priv->autostart) {
 		printf("WDT:   Not starting %s\n", dev->name);
 		return;
 	}
@@ -258,19 +258,22 @@ static int wdt_pre_probe(struct udevice *dev)
 	 * indicated by a hw_margin_ms property.
 	 */
 	ulong reset_period = 1000;
-	bool noautostart = false;
+	bool autostart = IS_ENABLED(CONFIG_WATCHDOG_AUTOSTART);
 	struct wdt_priv *priv;
 
 	if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) {
 		timeout = dev_read_u32_default(dev, "timeout-sec", timeout);
 		reset_period = dev_read_u32_default(dev, "hw_margin_ms",
 						    4 * reset_period) / 4;
-		noautostart = dev_read_bool(dev, "u-boot,noautostart");
+		if (dev_read_bool(dev, "u-boot,noautostart"))
+			autostart = false;
+		else if (dev_read_bool(dev, "u-boot,autostart"))
+			autostart = true;
 	}
 	priv = dev_get_uclass_priv(dev);
 	priv->timeout = timeout;
 	priv->reset_period = reset_period;
-	priv->noautostart = noautostart;
+	priv->autostart = autostart;
 	/*
 	 * Pretend this device was last reset "long" ago so the first
 	 * watchdog_reset will actually call its ->reset method.
-- 
2.37.2