From 96ec6983dba0bd694d09b819ec8ebf67d06bb966 Mon Sep 17 00:00:00 2001
From: anjiahao <anjiahao@xiaomi.com>
Date: Mon, 26 Dec 2022 19:28:34 +0800
Subject: [PATCH] watchdog:use 'V' to stop watchdog

Signed-off-by: anjiahao <anjiahao@xiaomi.com>
---
 drivers/timers/Kconfig    |  6 ++++++
 drivers/timers/watchdog.c | 43 ++++++++++++++++++++++++++++++++++++++-
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/drivers/timers/Kconfig b/drivers/timers/Kconfig
index d5416f49693..b0a86dd0bf5 100644
--- a/drivers/timers/Kconfig
+++ b/drivers/timers/Kconfig
@@ -354,6 +354,12 @@ config WATCHDOG_DEVPATH
 		Please, check how your specific chip or board uses this symbol.
 		FYI: It's NOT used by the Auto-monitor feature.
 
+config CONFIG_WATCHDOG_MAGIC_V
+	bool "Watchdog Device Magic num"
+	default Y
+	---help---
+		The watchdog can be stopped by writing 'V' to the watchdog's device node
+
 menuconfig WATCHDOG_AUTOMONITOR
 	bool "Auto-monitor"
 	---help---
diff --git a/drivers/timers/watchdog.c b/drivers/timers/watchdog.c
index 989ca1ec78e..cea342583a1 100644
--- a/drivers/timers/watchdog.c
+++ b/drivers/timers/watchdog.c
@@ -436,7 +436,48 @@ static ssize_t wdog_read(FAR struct file *filep, FAR char *buffer,
 static ssize_t wdog_write(FAR struct file *filep, FAR const char *buffer,
                           size_t buflen)
 {
-  return 0;
+#ifdef CONFIG_WATCHDOG_MAGIC_V
+  FAR struct inode                *inode = filep->f_inode;
+  FAR struct watchdog_upperhalf_s *upper;
+  FAR struct watchdog_lowerhalf_s *lower;
+  int err = 0;
+  int i;
+
+  upper = inode->i_private;
+  DEBUGASSERT(upper != NULL);
+  lower = upper->lower;
+  DEBUGASSERT(lower != NULL);
+
+  nxmutex_lock(&upper->lock);
+
+  for (i = 0; i < buflen; i++)
+    {
+      if (buffer[i] == 'V')
+        {
+#ifdef CONFIG_WATCHDOG_AUTOMONITOR
+          watchdog_automonitor_stop(upper);
+#else
+          err = lower->ops->stop(lower);
+#endif
+          break;
+        }
+    }
+
+  if (i == buflen)
+    {
+      err = lower->ops->keepalive(lower);
+    }
+
+  nxmutex_unlock(&upper->lock);
+
+  if (err < 0)
+    {
+      return err;
+    }
+
+#endif
+
+  return buflen;
 }
 
 /****************************************************************************