--- zzzz-none-000/linux-3.10.107/drivers/watchdog/at91rm9200_wdt.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/watchdog/at91rm9200_wdt.c	2021-02-04 17:41:59.000000000 +0000
@@ -12,27 +12,32 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/bitops.h>
+#include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-st.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
 #include <linux/uaccess.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
-#include <mach/at91_st.h>
 
 #define WDT_DEFAULT_TIME	5	/* seconds */
 #define WDT_MAX_TIME		256	/* seconds */
 
 static int wdt_time = WDT_DEFAULT_TIME;
 static bool nowayout = WATCHDOG_NOWAYOUT;
+static struct regmap *regmap_st;
 
 module_param(wdt_time, int, 0);
 MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
@@ -50,12 +55,33 @@
 
 /* ......................................................................... */
 
+static int at91rm9200_restart(struct notifier_block *this,
+					unsigned long mode, void *cmd)
+{
+	/*
+	 * Perform a hardware reset with the use of the Watchdog timer.
+	 */
+	regmap_write(regmap_st, AT91_ST_WDMR,
+		     AT91_ST_RSTEN | AT91_ST_EXTEN | 1);
+	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
+
+	mdelay(2000);
+
+	pr_emerg("Unable to restart system\n");
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block at91rm9200_restart_nb = {
+	.notifier_call = at91rm9200_restart,
+	.priority = 192,
+};
+
 /*
  * Disable the watchdog.
  */
 static inline void at91_wdt_stop(void)
 {
-	at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN);
+	regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN);
 }
 
 /*
@@ -63,9 +89,9 @@
  */
 static inline void at91_wdt_start(void)
 {
-	at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
+	regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
 				(((65536 * wdt_time) >> 8) & AT91_ST_WDV));
-	at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
+	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
 }
 
 /*
@@ -73,7 +99,7 @@
  */
 static inline void at91_wdt_reload(void)
 {
-	at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
+	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
 }
 
 /* ......................................................................... */
@@ -203,16 +229,32 @@
 
 static int at91wdt_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
+	struct device *parent;
 	int res;
 
 	if (at91wdt_miscdev.parent)
 		return -EBUSY;
 	at91wdt_miscdev.parent = &pdev->dev;
 
+	parent = dev->parent;
+	if (!parent) {
+		dev_err(dev, "no parent\n");
+		return -ENODEV;
+	}
+
+	regmap_st = syscon_node_to_regmap(parent->of_node);
+	if (IS_ERR(regmap_st))
+		return -ENODEV;
+
 	res = misc_register(&at91wdt_miscdev);
 	if (res)
 		return res;
 
+	res = register_restart_handler(&at91rm9200_restart_nb);
+	if (res)
+		dev_warn(dev, "failed to register restart handler\n");
+
 	pr_info("AT91 Watchdog Timer enabled (%d seconds%s)\n",
 		wdt_time, nowayout ? ", nowayout" : "");
 	return 0;
@@ -220,11 +262,15 @@
 
 static int at91wdt_remove(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	int res;
 
-	res = misc_deregister(&at91wdt_miscdev);
-	if (!res)
-		at91wdt_miscdev.parent = NULL;
+	res = unregister_restart_handler(&at91rm9200_restart_nb);
+	if (res)
+		dev_warn(dev, "failed to unregister restart handler\n");
+
+	misc_deregister(&at91wdt_miscdev);
+	at91wdt_miscdev.parent = NULL;
 
 	return res;
 }
@@ -267,9 +313,8 @@
 	.suspend	= at91wdt_suspend,
 	.resume		= at91wdt_resume,
 	.driver		= {
-		.name	= "at91_wdt",
-		.owner	= THIS_MODULE,
-		.of_match_table = of_match_ptr(at91_wdt_dt_ids),
+		.name	= "atmel_st_watchdog",
+		.of_match_table = at91_wdt_dt_ids,
 	},
 };
 
@@ -297,5 +342,4 @@
 MODULE_AUTHOR("Andrew Victor");
 MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
-MODULE_ALIAS("platform:at91_wdt");
+MODULE_ALIAS("platform:atmel_st_watchdog");