linux-kernel - [PATCH 1/2] platform/x86: portwell-ec: Add suspend/resume support for watchdog

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Message-ID: <885c90f6-3669-4c7b-85fe-c1999121e66f@portwell.com.tw>
Date: Fri, 27 Jun 2025 17:14:43 +0800
From: jesse huang <jesse.huang@...twell.com.tw>
To: hansg@...nel.org, ilpo.jarvinen@...ux.intel.com, jdelvare@...e.com,
 linux@...ck-us.net
Cc: linux-kernel@...r.kernel.org, platform-driver-x86@...r.kernel.org,
 linux-hwmon@...r.kernel.org
Subject: [PATCH 1/2] platform/x86: portwell-ec: Add suspend/resume support for
 watchdog

Portwell EC does not disable the watchdog during suspend. To avoid unwanted
resets, this patch adds suspend and resume callbacks (pwec_suspend() and
pwec_resume()) to the driver.

The watchdog is stopped in pwec_suspend() and restarted in pwec_resume() if
it was active before suspend.

Signed-off-by: Yen-Chi Huang <jesse.huang@...twell.com.tw>
---
 drivers/platform/x86/portwell-ec.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/platform/x86/portwell-ec.c b/drivers/platform/x86/portwell-ec.c
index 8b788822237b..a68522aaa3fa 100644
--- a/drivers/platform/x86/portwell-ec.c
+++ b/drivers/platform/x86/portwell-ec.c
@@ -245,11 +245,29 @@ static int pwec_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static int pwec_suspend(struct platform_device *pdev, pm_message_t message)
+{
+	if (watchdog_active(&ec_wdt_dev))
+		return pwec_wdt_stop(&ec_wdt_dev);
+
+	return 0;
+}
+
+static int pwec_resume(struct platform_device *pdev)
+{
+	if (watchdog_active(&ec_wdt_dev))
+		return pwec_wdt_start(&ec_wdt_dev);
+
+	return 0;
+}
+
 static struct platform_driver pwec_driver = {
 	.driver = {
 		.name = "portwell-ec",
 	},
 	.probe = pwec_probe,
+	.suspend = pm_ptr(pwec_suspend),
+	.resume = pm_ptr(pwec_resume),
 };
 
 static struct platform_device *pwec_dev;
-- 
2.34.1