[RESEND PATCH] watchdog: sbsa_gwdt: add force_enable module parameter

[Zexin Wang]

The sbsa_gwdt driver only manages and registers the watchdog timer if it
was already enabled by a previous boot stage (such as firmware). If the
watchdog was left disabled prior to entering the kernel, the driver
will not actively enable it during the probe phase.

Introduce a new module parameter 'force_enable' to allow overriding this
behavior. When 'force_enable' is set, the driver will forcibly start
the watchdog and register it as running during the probe phase, even if
it was disabled in the previous boot stage.

Signed-off-by: Zexin Wang <ot_zexin.wang@xxxxxxxxxxxx>
---
 drivers/watchdog/sbsa_gwdt.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c
index e04d42cc7774..4b49e1aeef84 100644
--- a/drivers/watchdog/sbsa_gwdt.c
+++ b/drivers/watchdog/sbsa_gwdt.c
@@ -122,6 +122,11 @@ MODULE_PARM_DESC(nowayout,
 		 "Watchdog cannot be stopped once started (default="
 		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
+static bool force_enable;
+module_param(force_enable, bool, 0);
+MODULE_PARM_DESC(force_enable,
+		 "Force enable watchdog on probe (default=0)");
+
 /*
  * Arm Base System Architecture 1.0 introduces watchdog v1 which
  * increases the length watchdog offset register to 48 bits.
@@ -296,6 +301,7 @@ static int sbsa_gwdt_probe(struct platform_device *pdev)
 	struct sbsa_gwdt *gwdt;
 	int ret, irq;
 	u32 status;
+	bool force_action;
 
 	gwdt = devm_kzalloc(dev, sizeof(*gwdt), GFP_KERNEL);
 	if (!gwdt)
@@ -386,14 +392,27 @@ static int sbsa_gwdt_probe(struct platform_device *pdev)
 	 */
 	sbsa_gwdt_set_timeout(wdd, wdd->timeout);
 
+	force_action = force_enable && !(status & SBSA_GWDT_WCS_EN);
+	if (force_action) {
+		sbsa_gwdt_start(wdd);
+		set_bit(WDOG_HW_RUNNING, &wdd->status);
+		dev_info(dev, "Watchdog force enabled.\n");
+	}
+
 	watchdog_stop_on_reboot(wdd);
 	ret = devm_watchdog_register_device(dev, wdd);
-	if (ret)
+	if (ret) {
+		dev_err(dev, "Failed to register watchdog: %d\n", ret);
+		if (force_action) {
+			clear_bit(WDOG_HW_RUNNING, &wdd->status);
+			sbsa_gwdt_stop(wdd);
+		}
 		return ret;
+	}
 
 	dev_info(dev, "Initialized with %ds timeout @ %u Hz, action=%d.%s\n",
 		 wdd->timeout, gwdt->clk, action,
-		 status & SBSA_GWDT_WCS_EN ? " [enabled]" : "");
+		 watchdog_hw_running(wdd) ? " [enabled]" : "");
 
 	return 0;
 }
-- 
2.45.2