361 lines
		
	
	
		
			9.8 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			361 lines
		
	
	
		
			9.8 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
This generic GPIO watchdog is used on Huawei E970 (brcm47xx)
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Signed-off-by: Mathias Adam <m.adam--openwrt@adamis.de>
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--- a/drivers/watchdog/Kconfig
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+++ b/drivers/watchdog/Kconfig
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@@ -1216,6 +1216,15 @@ config WDT_MTX1
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 	  Hardware driver for the MTX-1 boards. This is a watchdog timer that
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 	  will reboot the machine after a 100 seconds timer expired.
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+config GPIO_WDT
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+	tristate "GPIO Hardware Watchdog"
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+ 	help
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+	  Hardware driver for GPIO-controlled watchdogs. GPIO pin and
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+	  toggle interval settings are platform-specific. The driver
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+	  will stop toggling the GPIO (i.e. machine reboots) after a
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+	  100 second timer expired and no process has written to
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+	  /dev/watchdog during that time.
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+
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 config PNX833X_WDT
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 	tristate "PNX833x Hardware Watchdog"
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 	depends on SOC_PNX8335
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--- a/drivers/watchdog/Makefile
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+++ b/drivers/watchdog/Makefile
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@@ -140,6 +140,7 @@ obj-$(CONFIG_RC32434_WDT) += rc32434_wdt
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 obj-$(CONFIG_INDYDOG) += indydog.o
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 obj-$(CONFIG_JZ4740_WDT) += jz4740_wdt.o
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 obj-$(CONFIG_WDT_MTX1) += mtx-1_wdt.o
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+obj-$(CONFIG_GPIO_WDT) += old_gpio_wdt.o
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 obj-$(CONFIG_PNX833X_WDT) += pnx833x_wdt.o
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 obj-$(CONFIG_SIBYTE_WDOG) += sb_wdog.o
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 obj-$(CONFIG_AR7_WDT) += ar7_wdt.o
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--- /dev/null
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+++ b/drivers/watchdog/old_gpio_wdt.c
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@@ -0,0 +1,301 @@
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+/*
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+ *      Driver for GPIO-controlled Hardware Watchdogs.
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+ *
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+ *      Copyright (C) 2013 Mathias Adam <m.adam--linux@adamis.de>
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+ *
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+ *      Replaces mtx1_wdt (driver for the MTX-1 Watchdog):
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+ *
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+ *      (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
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+ *                              All Rights Reserved.
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+ *                              http://www.4g-systems.biz
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+ *
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+ *      (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
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+ *
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+ *      This program is free software; you can redistribute it and/or
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+ *      modify it under the terms of the GNU General Public License
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+ *      as published by the Free Software Foundation; either version
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+ *      2 of the License, or (at your option) any later version.
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+ *
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+ *      Neither Michael Stickel nor 4G Systems admit liability nor provide
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+ *      warranty for any of this software. This material is provided
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+ *      "AS-IS" and at no charge.
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+ *
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+ *      (c) Copyright 2005    4G Systems <info@4g-systems.biz>
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+ *
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+ *      Release 0.01.
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+ *      Author: Michael Stickel  michael.stickel@4g-systems.biz
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+ *
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+ *      Release 0.02.
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+ *      Author: Florian Fainelli florian@openwrt.org
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+ *              use the Linux watchdog/timer APIs
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+ *
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+ *      Release 0.03.
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+ *      Author: Mathias Adam <m.adam--linux@adamis.de>
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+ *              make it a generic gpio watchdog driver
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+ *
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+ *      The Watchdog is configured to reset the MTX-1
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+ *      if it is not triggered for 100 seconds.
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+ *      It should not be triggered more often than 1.6 seconds.
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+ *
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+ *      A timer triggers the watchdog every 5 seconds, until
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+ *      it is opened for the first time. After the first open
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+ *      it MUST be triggered every 2..95 seconds.
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+ */
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+
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+#include <linux/module.h>
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+#include <linux/moduleparam.h>
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+#include <linux/types.h>
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+#include <linux/errno.h>
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+#include <linux/miscdevice.h>
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+#include <linux/fs.h>
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+#include <linux/init.h>
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+#include <linux/ioport.h>
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+#include <linux/timer.h>
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+#include <linux/completion.h>
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+#include <linux/jiffies.h>
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+#include <linux/watchdog.h>
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+#include <linux/platform_device.h>
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+#include <linux/io.h>
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+#include <linux/uaccess.h>
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+#include <linux/gpio.h>
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+#include <linux/old_gpio_wdt.h>
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+
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+static int ticks = 100 * HZ;
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+
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+static struct {
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+	struct completion stop;
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+	spinlock_t lock;
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+	int running;
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+	struct timer_list timer;
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+	int queue;
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+	int default_ticks;
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+	unsigned long inuse;
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+	unsigned gpio;
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+	unsigned int gstate;
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+	int interval;
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+	int first_interval;
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+} gpio_wdt_device;
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+
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+static void gpio_wdt_trigger(unsigned long unused)
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+{
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+	spin_lock(&gpio_wdt_device.lock);
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+	if (gpio_wdt_device.running && ticks > 0)
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+		ticks -= gpio_wdt_device.interval;
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+
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+	/* toggle wdt gpio */
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+	gpio_wdt_device.gstate = !gpio_wdt_device.gstate;
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+	gpio_set_value(gpio_wdt_device.gpio, gpio_wdt_device.gstate);
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+
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+	if (gpio_wdt_device.queue && ticks > 0)
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+		mod_timer(&gpio_wdt_device.timer, jiffies + gpio_wdt_device.interval);
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+	else
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+		complete(&gpio_wdt_device.stop);
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+	spin_unlock(&gpio_wdt_device.lock);
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+}
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+
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+static void gpio_wdt_reset(void)
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+{
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+	ticks = gpio_wdt_device.default_ticks;
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+}
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+
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+
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+static void gpio_wdt_start(void)
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+{
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+	unsigned long flags;
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+
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+	spin_lock_irqsave(&gpio_wdt_device.lock, flags);
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+	if (!gpio_wdt_device.queue) {
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+		gpio_wdt_device.queue = 1;
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+		gpio_wdt_device.gstate = 1;
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+		gpio_set_value(gpio_wdt_device.gpio, 1);
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+		mod_timer(&gpio_wdt_device.timer, jiffies + gpio_wdt_device.first_interval);
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+	}
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+	gpio_wdt_device.running++;
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+	spin_unlock_irqrestore(&gpio_wdt_device.lock, flags);
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+}
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+
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+static int gpio_wdt_stop(void)
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+{
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+	unsigned long flags;
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+
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+	spin_lock_irqsave(&gpio_wdt_device.lock, flags);
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+	if (gpio_wdt_device.queue) {
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+		gpio_wdt_device.queue = 0;
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+		gpio_wdt_device.gstate = 0;
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+		gpio_set_value(gpio_wdt_device.gpio, 0);
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+	}
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+	ticks = gpio_wdt_device.default_ticks;
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+	spin_unlock_irqrestore(&gpio_wdt_device.lock, flags);
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+	return 0;
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+}
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+
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+/* Filesystem functions */
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+
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+static int gpio_wdt_open(struct inode *inode, struct file *file)
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+{
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+	if (test_and_set_bit(0, &gpio_wdt_device.inuse))
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+		return -EBUSY;
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+	return nonseekable_open(inode, file);
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+}
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+
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+
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+static int gpio_wdt_release(struct inode *inode, struct file *file)
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+{
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+	clear_bit(0, &gpio_wdt_device.inuse);
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+	return 0;
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+}
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+
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+static long gpio_wdt_ioctl(struct file *file, unsigned int cmd,
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+							unsigned long arg)
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+{
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+	void __user *argp = (void __user *)arg;
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+	int __user *p = (int __user *)argp;
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+	unsigned int value;
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+	static const struct watchdog_info ident = {
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+		.options = WDIOF_CARDRESET,
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+		.identity = "GPIO WDT",
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+	};
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+
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+	switch (cmd) {
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+	case WDIOC_GETSUPPORT:
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+		if (copy_to_user(argp, &ident, sizeof(ident)))
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+			return -EFAULT;
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+		break;
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+	case WDIOC_GETSTATUS:
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+	case WDIOC_GETBOOTSTATUS:
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+		put_user(0, p);
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+		break;
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+	case WDIOC_SETOPTIONS:
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+		if (get_user(value, p))
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+			return -EFAULT;
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+		if (value & WDIOS_ENABLECARD)
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+			gpio_wdt_start();
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+		else if (value & WDIOS_DISABLECARD)
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+			gpio_wdt_stop();
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+		else
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+			return -EINVAL;
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+		return 0;
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+	case WDIOC_KEEPALIVE:
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+		gpio_wdt_reset();
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+		break;
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+	default:
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+		return -ENOTTY;
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+	}
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+	return 0;
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+}
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+
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+
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+static ssize_t gpio_wdt_write(struct file *file, const char *buf,
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+						size_t count, loff_t *ppos)
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+{
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+	if (!count)
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+		return -EIO;
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+	gpio_wdt_reset();
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+	return count;
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+}
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+
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+static const struct file_operations gpio_wdt_fops = {
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+	.owner		= THIS_MODULE,
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+	.llseek		= no_llseek,
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+	.unlocked_ioctl	= gpio_wdt_ioctl,
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+	.open		= gpio_wdt_open,
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+	.write		= gpio_wdt_write,
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+	.release	= gpio_wdt_release,
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+};
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+
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+
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+static struct miscdevice gpio_wdt_misc = {
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+	.minor	= WATCHDOG_MINOR,
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+	.name	= "watchdog",
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+	.fops	= &gpio_wdt_fops,
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+};
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+
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+
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+static int gpio_wdt_probe(struct platform_device *pdev)
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+{
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+	int ret;
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+	struct gpio_wdt_platform_data *gpio_wdt_data = pdev->dev.platform_data;
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+
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+	gpio_wdt_device.gpio = gpio_wdt_data->gpio;
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+	gpio_wdt_device.interval = gpio_wdt_data->interval;
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+	gpio_wdt_device.first_interval = gpio_wdt_data->first_interval;
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+	if (gpio_wdt_device.first_interval <= 0) {
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+		gpio_wdt_device.first_interval = gpio_wdt_device.interval;
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+	}
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+
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+	ret = gpio_request(gpio_wdt_device.gpio, "gpio-wdt");
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+	if (ret < 0) {
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+		dev_err(&pdev->dev, "failed to request gpio");
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+		return ret;
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+	}
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+
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+	spin_lock_init(&gpio_wdt_device.lock);
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+	init_completion(&gpio_wdt_device.stop);
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+	gpio_wdt_device.queue = 0;
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+	clear_bit(0, &gpio_wdt_device.inuse);
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+	setup_timer(&gpio_wdt_device.timer, gpio_wdt_trigger, 0L);
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+	gpio_wdt_device.default_ticks = ticks;
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+
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+	gpio_wdt_start();
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+	dev_info(&pdev->dev, "GPIO Hardware Watchdog driver (gpio=%i interval=%i/%i)\n",
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+		gpio_wdt_data->gpio, gpio_wdt_data->first_interval, gpio_wdt_data->interval);
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+	return 0;
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+}
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+
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+static int gpio_wdt_remove(struct platform_device *pdev)
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+{
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+	/* FIXME: do we need to lock this test ? */
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+	if (gpio_wdt_device.queue) {
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+		gpio_wdt_device.queue = 0;
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+		wait_for_completion(&gpio_wdt_device.stop);
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+	}
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+
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+	gpio_free(gpio_wdt_device.gpio);
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+	misc_deregister(&gpio_wdt_misc);
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+	return 0;
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+}
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+
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+static struct platform_driver gpio_wdt_driver = {
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+	.probe = gpio_wdt_probe,
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+	.remove = gpio_wdt_remove,
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+	.driver.name = "gpio-wdt",
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+	.driver.owner = THIS_MODULE,
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+};
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+
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+static int __init gpio_wdt_init(void)
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+{
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+	return platform_driver_register(&gpio_wdt_driver);
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+}
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+arch_initcall(gpio_wdt_init);
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+
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+/*
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+ * We do wdt initialization in two steps: arch_initcall probes the wdt
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+ * very early to start pinging the watchdog (misc devices are not yet
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+ * available), and later module_init() just registers the misc device.
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+ */
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+static int gpio_wdt_init_late(void)
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+{
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+	int ret;
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+
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+	ret = misc_register(&gpio_wdt_misc);
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+	if (ret < 0) {
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+		pr_err("GPIO_WDT: failed to register misc device\n");
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+		return ret;
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+	}
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+	return 0;
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+}
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+#ifndef MODULE
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+module_init(gpio_wdt_init_late);
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+#endif
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+
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+static void __exit gpio_wdt_exit(void)
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+{
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+	platform_driver_unregister(&gpio_wdt_driver);
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+}
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+module_exit(gpio_wdt_exit);
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+
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+MODULE_AUTHOR("Michael Stickel, Florian Fainelli, Mathias Adam");
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+MODULE_DESCRIPTION("Driver for GPIO hardware watchdogs");
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+MODULE_LICENSE("GPL");
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+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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+MODULE_ALIAS("platform:gpio-wdt");
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--- /dev/null
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+++ b/include/linux/old_gpio_wdt.h
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@@ -0,0 +1,21 @@
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+/*
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+ *  Definitions for the GPIO watchdog driver
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+ *
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+ *  Copyright (C) 2013 Mathias Adam <m.adam--linux@adamis.de>
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+ *
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+ *  This program is free software; you can redistribute it and/or modify
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+ *  it under the terms of the GNU General Public License version 2 as
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+ *  published by the Free Software Foundation.
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+ *
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+ */
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+
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+#ifndef _GPIO_WDT_H_
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+#define _GPIO_WDT_H_
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+
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+struct gpio_wdt_platform_data {
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+	int	gpio;		/* GPIO line number */
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+	int	interval;	/* watchdog reset interval in system ticks */
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+	int	first_interval;	/* first wd reset interval in system ticks */
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+};
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+
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+#endif /* _GPIO_WDT_H_ */
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