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From:   Fengquan Chen <Fengquan.Chen@mediatek.com>
To:     Wim Van Sebroeck <wim@linux-watchdog.org>,
        Guenter Roeck <linux@roeck-us.net>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        <linux-watchdog@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
CC:     <fengquan.chen@mediatek.com>, <tinghan.shen@mediatek.com>,
        <randy.wu@mediatek.com>, <rex-bc.chen@mediatek.com>,
        <christine.zhu@mediatek.com>, <joe.yang@mediatek.com>,
        <zhishuang.zhang@mediatek.com>
Subject: [PATCH] watchdog: mtk: add disable_wdt_extrst support
Date:   Thu, 2 Sep 2021 16:04:41 +0800
Message-ID: <1630569881-6032-2-git-send-email-Fengquan.Chen@mediatek.com>
In-Reply-To: <1630569881-6032-1-git-send-email-Fengquan.Chen@mediatek.com>
References: <1630569881-6032-1-git-send-email-Fengquan.Chen@mediatek.com>
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From: "fengquan.chen" <fengquan.chen@mediatek.com>

In some cases, we may need watchdog just to trigger an
internal soc reset without sending any output signal.

Provide a disable_wdt_extrst parameter for configuration.
We can disable or enable it just by configuring dts.

igned-off-by: Fengquan Chen <fengquan.chen@mediatek.com>
---
 drivers/watchdog/mtk_wdt.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index 97ca993..4824c07 100644
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -63,6 +63,7 @@ struct mtk_wdt_dev {
 	void __iomem *wdt_base;
 	spinlock_t lock; /* protects WDT_SWSYSRST reg */
 	struct reset_controller_dev rcdev;
+	bool disable_wdt_extrst;
 };
 
 struct mtk_wdt_data {
@@ -240,6 +241,8 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
 
 	reg = ioread32(wdt_base + WDT_MODE);
 	reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
+	if (mtk_wdt->disable_wdt_extrst)
+		reg &= ~WDT_MODE_EXRST_EN;
 	reg |= (WDT_MODE_EN | WDT_MODE_KEY);
 	iowrite32(reg, wdt_base + WDT_MODE);
 
@@ -309,6 +312,10 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 		if (err)
 			return err;
 	}
+
+	mtk_wdt->disable_wdt_extrst =
+		of_property_read_bool(dev->of_node, "disable_extrst");
+
 	return 0;
 }
 
-- 
1.8.1.1.dirty