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			411 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			411 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| --- /dev/null
 | |
| +++ b/drivers/watchdog/gemini_wdt.c
 | |
| @@ -0,0 +1,378 @@
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| +/*
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| + *  Watchdog driver for Cortina Systems Gemini SoC
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| + *
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| + *  Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
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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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| +#include <linux/kernel.h>
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| +#include <linux/init.h>
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| +#include <linux/module.h>
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| +#include <linux/io.h>
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| +#include <linux/fs.h>
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| +#include <linux/uaccess.h>
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| +#include <linux/miscdevice.h>
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| +#include <linux/platform_device.h>
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| +#include <linux/watchdog.h>
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| +#include <linux/slab.h>
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| +
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| +#define GEMINI_WDCOUNTER	0x0
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| +#define GEMINI_WDLOAD		0x4
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| +#define GEMINI_WDRESTART	0x8
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| +
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| +#define WDRESTART_MAGIC		0x5AB9
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| +
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| +#define GEMINI_WDCR		0xC
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| +
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| +#define WDCR_CLOCK_5MHZ		(1 << 4)
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| +#define WDCR_SYS_RST		(1 << 1)
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| +#define WDCR_ENABLE		(1 << 0)
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| +
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| +#define WDT_CLOCK		5000000		/* 5 MHz */
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| +#define WDT_DEFAULT_TIMEOUT	13
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| +#define WDT_MAX_TIMEOUT		(0xFFFFFFFF / WDT_CLOCK)
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| +
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| +/* status bits */
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| +#define WDT_ACTIVE		0
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| +#define WDT_OK_TO_CLOSE		1
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| +
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| +static unsigned int timeout = WDT_DEFAULT_TIMEOUT;
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| +static int nowayout = WATCHDOG_NOWAYOUT;
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| +
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| +static DEFINE_SPINLOCK(gemini_wdt_lock);
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| +
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| +static struct platform_device *gemini_wdt_dev;
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| +
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| +struct gemini_wdt_struct {
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| +	struct resource		*res;
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| +	struct device		*dev;
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| +	void __iomem		*base;
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| +	unsigned long		status;
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| +};
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| +
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| +static struct watchdog_info gemini_wdt_info = {
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| +	.identity	= "Gemini watchdog",
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| +	.options	= WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
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| +			  WDIOF_SETTIMEOUT,
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| +};
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| +
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| +/* Disable the watchdog. */
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| +static void gemini_wdt_stop(struct gemini_wdt_struct *gemini_wdt)
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| +{
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| +	spin_lock(&gemini_wdt_lock);
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| +
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| +	__raw_writel(0, gemini_wdt->base + GEMINI_WDCR);
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| +
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| +	clear_bit(WDT_ACTIVE, &gemini_wdt->status);
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| +
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| +	spin_unlock(&gemini_wdt_lock);
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| +}
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| +
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| +/* Service the watchdog */
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| +static void gemini_wdt_service(struct gemini_wdt_struct *gemini_wdt)
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| +{
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| +	__raw_writel(WDRESTART_MAGIC, gemini_wdt->base + GEMINI_WDRESTART);
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| +}
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| +
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| +/* Enable and reset the watchdog. */
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| +static void gemini_wdt_start(struct gemini_wdt_struct *gemini_wdt)
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| +{
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| +	spin_lock(&gemini_wdt_lock);
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| +
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| +	__raw_writel(timeout * WDT_CLOCK, gemini_wdt->base + GEMINI_WDLOAD);
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| +
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| +	gemini_wdt_service(gemini_wdt);
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| +
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| +	/* set clock before enabling */
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| +	__raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST,
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| +			gemini_wdt->base + GEMINI_WDCR);
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| +
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| +	__raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST | WDCR_ENABLE,
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| +			gemini_wdt->base + GEMINI_WDCR);
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| +
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| +	set_bit(WDT_ACTIVE, &gemini_wdt->status);
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| +
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| +	spin_unlock(&gemini_wdt_lock);
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| +}
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| +
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| +/* Watchdog device is opened, and watchdog starts running. */
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| +static int gemini_wdt_open(struct inode *inode, struct file *file)
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| +{
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| +	struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(gemini_wdt_dev);
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| +
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| +	if (test_bit(WDT_ACTIVE, &gemini_wdt->status))
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| +		return -EBUSY;
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| +
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| +	file->private_data = gemini_wdt;
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| +
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| +	gemini_wdt_start(gemini_wdt);
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| +
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| +	return nonseekable_open(inode, file);
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| +}
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| +
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| +/* Close the watchdog device. */
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| +static int gemini_wdt_close(struct inode *inode, struct file *file)
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| +{
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| +	struct gemini_wdt_struct *gemini_wdt = file->private_data;
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| +
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| +	/* Disable the watchdog if possible */
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| +	if (test_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status))
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| +		gemini_wdt_stop(gemini_wdt);
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| +	else
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| +		dev_warn(gemini_wdt->dev, "Device closed unexpectedly - timer will not stop\n");
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| +
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| +	return 0;
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| +}
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| +
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| +/* Handle commands from user-space. */
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| +static long gemini_wdt_ioctl(struct file *file, unsigned int cmd,
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| +			     unsigned long arg)
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| +{
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| +	struct gemini_wdt_struct *gemini_wdt = file->private_data;
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| +
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| +	int value;
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| +
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| +	switch (cmd) {
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| +	case WDIOC_KEEPALIVE:
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| +		gemini_wdt_service(gemini_wdt);
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| +		return 0;
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| +
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| +	case WDIOC_GETSUPPORT:
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| +		return copy_to_user((struct watchdog_info *)arg, &gemini_wdt_info,
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| +			sizeof(gemini_wdt_info)) ? -EFAULT : 0;
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| +
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| +	case WDIOC_SETTIMEOUT:
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| +		if (get_user(value, (int *)arg))
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| +			return -EFAULT;
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| +
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| +		if ((value < 1) || (value > WDT_MAX_TIMEOUT))
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| +			return -EINVAL;
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| +
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| +		timeout = value;
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| +
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| +		/* restart wdt to use new timeout */
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| +		gemini_wdt_stop(gemini_wdt);
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| +		gemini_wdt_start(gemini_wdt);
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| +
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| +		/* Fall through */
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| +	case WDIOC_GETTIMEOUT:
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| +		return put_user(timeout, (int *)arg);
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| +
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| +	case WDIOC_GETTIMELEFT:
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| +		value = __raw_readl(gemini_wdt->base + GEMINI_WDCOUNTER);
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| +		return put_user(value / WDT_CLOCK, (int *)arg);
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| +
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| +	default:
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| +		return -ENOTTY;
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| +	}
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| +}
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| +
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| +/* Refresh the watchdog whenever device is written to. */
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| +static ssize_t gemini_wdt_write(struct file *file, const char *data,
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| +						size_t len, loff_t *ppos)
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| +{
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| +	struct gemini_wdt_struct *gemini_wdt = file->private_data;
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| +
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| +	if (len) {
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| +		if (!nowayout) {
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| +			size_t i;
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| +
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| +			clear_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status);
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| +			for (i = 0; i != len; i++) {
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| +				char c;
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| +
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| +				if (get_user(c, data + i))
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| +					return -EFAULT;
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| +				if (c == 'V')
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| +					set_bit(WDT_OK_TO_CLOSE,
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| +						&gemini_wdt->status);
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| +			}
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| +		}
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| +		gemini_wdt_service(gemini_wdt);
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| +	}
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| +
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| +	return len;
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| +}
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| +
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| +static const struct file_operations gemini_wdt_fops = {
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| +	.owner		= THIS_MODULE,
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| +	.llseek		= no_llseek,
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| +	.unlocked_ioctl = gemini_wdt_ioctl,
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| +	.open		= gemini_wdt_open,
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| +	.release	= gemini_wdt_close,
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| +	.write		= gemini_wdt_write,
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| +};
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| +
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| +static struct miscdevice gemini_wdt_miscdev = {
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| +	.minor		= WATCHDOG_MINOR,
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| +	.name		= "watchdog",
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| +	.fops		= &gemini_wdt_fops,
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| +};
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| +
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| +static void gemini_wdt_shutdown(struct platform_device *pdev)
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| +{
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| +	struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
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| +
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| +	gemini_wdt_stop(gemini_wdt);
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| +}
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| +
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| +static int gemini_wdt_probe(struct platform_device *pdev)
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| +{
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| +	int ret;
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| +	int res_size;
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| +	struct resource *res;
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| +	void __iomem *base;
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| +	struct gemini_wdt_struct *gemini_wdt;
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| +	unsigned int reg;
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| +
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| +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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| +	if (!res) {
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| +		dev_err(&pdev->dev, "can't get device resources\n");
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| +		return -ENODEV;
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| +	}
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| +
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| +	res_size = resource_size(res);
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| +	if (!request_mem_region(res->start, res_size, res->name)) {
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| +		dev_err(&pdev->dev, "can't allocate %d bytes at %d address\n",
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| +			res_size, res->start);
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| +		return -ENOMEM;
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| +	}
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| +
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| +	base = ioremap(res->start, res_size);
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| +	if (!base) {
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| +		dev_err(&pdev->dev, "ioremap failed\n");
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| +		ret = -EIO;
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| +		goto fail0;
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| +	}
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| +
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| +	gemini_wdt = kzalloc(sizeof(struct gemini_wdt_struct), GFP_KERNEL);
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| +	if (!gemini_wdt) {
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| +		dev_err(&pdev->dev, "can't allocate interface\n");
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| +		ret = -ENOMEM;
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| +		goto fail1;
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| +	}
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| +
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| +	/* Setup gemini_wdt driver structure */
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| +	gemini_wdt->base = base;
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| +	gemini_wdt->res = res;
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| +
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| +	/* Set up platform driver data */
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| +	platform_set_drvdata(pdev, gemini_wdt);
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| +	gemini_wdt_dev = pdev;
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| +
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| +	if (gemini_wdt_miscdev.parent) {
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| +		ret = -EBUSY;
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| +		goto fail2;
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| +	}
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| +
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| +	gemini_wdt_miscdev.parent = &pdev->dev;
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| +
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| +	reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
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| +	if (reg & WDCR_ENABLE) {
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| +		/* Watchdog was enabled by the bootloader, disable it. */
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| +		reg &= ~(WDCR_ENABLE);
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| +		__raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
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| +	}
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| +
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| +	ret = misc_register(&gemini_wdt_miscdev);
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| +	if (ret)
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| +		goto fail2;
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| +
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| +	return 0;
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| +
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| +fail2:
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| +	platform_set_drvdata(pdev, NULL);
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| +	kfree(gemini_wdt);
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| +fail1:
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| +	iounmap(base);
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| +fail0:
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| +	release_mem_region(res->start, res_size);
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| +
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| +	return ret;
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| +}
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| +
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| +static int gemini_wdt_remove(struct platform_device *pdev)
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| +{
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| +	struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
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| +
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| +	platform_set_drvdata(pdev, NULL);
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| +	misc_deregister(&gemini_wdt_miscdev);
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| +	gemini_wdt_dev = NULL;
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| +	iounmap(gemini_wdt->base);
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| +	release_mem_region(gemini_wdt->res->start, resource_size(gemini_wdt->res));
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| +
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| +	kfree(gemini_wdt);
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| +
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| +	return 0;
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| +}
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| +
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| +#ifdef CONFIG_PM
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| +static int gemini_wdt_suspend(struct platform_device *pdev, pm_message_t message)
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| +{
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| +	struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
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| +	unsigned int reg;
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| +
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| +	reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
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| +	reg &= ~(WDCR_WDENABLE);
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| +	__raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
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| +
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| +	return 0;
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| +}
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| +
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| +static int gemini_wdt_resume(struct platform_device *pdev)
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| +{
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| +	struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
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| +	unsigned int reg;
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| +
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| +	if (gemini_wdt->status) {
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| +		reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
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| +		reg |= WDCR_WDENABLE;
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| +		__raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
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| +	}
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| +
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| +	return 0;
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| +}
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| +#else
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| +#define gemini_wdt_suspend	NULL
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| +#define gemini_wdt_resume	NULL
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| +#endif
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| +
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| +static struct platform_driver gemini_wdt_driver = {
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| +	.probe		= gemini_wdt_probe,
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| +	.remove		= gemini_wdt_remove,
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| +	.shutdown	= gemini_wdt_shutdown,
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| +	.suspend	= gemini_wdt_suspend,
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| +	.resume		= gemini_wdt_resume,
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| +	.driver		= {
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| +		.name	= "gemini-wdt",
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| +		.owner	= THIS_MODULE,
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| +	},
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| +};
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| +
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| +static int __init gemini_wdt_init(void)
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| +{
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| +	return platform_driver_probe(&gemini_wdt_driver, gemini_wdt_probe);
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| +}
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| +
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| +static void __exit gemini_wdt_exit(void)
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| +{
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| +	platform_driver_unregister(&gemini_wdt_driver);
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| +}
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| +
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| +module_init(gemini_wdt_init);
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| +module_exit(gemini_wdt_exit);
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| +
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| +module_param(timeout, uint, 0);
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| +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
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| +
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| +module_param(nowayout, int, 0);
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| +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
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| +
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| +MODULE_AUTHOR("Paulius Zaleckas");
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| +MODULE_DESCRIPTION("Watchdog driver for Gemini");
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| +MODULE_LICENSE("GPL");
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| +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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| +MODULE_ALIAS("platform:gemini-wdt");
 | |
| --- a/drivers/watchdog/Kconfig
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| +++ b/drivers/watchdog/Kconfig
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| @@ -199,6 +199,16 @@ config 977_WATCHDOG
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|  
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|  	  Not sure? It's safe to say N.
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|  
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| +config GEMINI_WATCHDOG
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| +	tristate "Gemini watchdog"
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| +	depends on ARCH_GEMINI
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| +	help
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| +	  Say Y here if to include support for the watchdog timer
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| +	  embedded in the Cortina Systems Gemini family of devices.
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| +
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| +	  To compile this driver as a module, choose M here: the
 | |
| +	  module will be called gemini_wdt.
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| +
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|  config IXP4XX_WATCHDOG
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|  	tristate "IXP4xx Watchdog"
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|  	depends on ARCH_IXP4XX
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| --- a/drivers/watchdog/Makefile
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| +++ b/drivers/watchdog/Makefile
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| @@ -37,6 +37,7 @@ obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.
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|  obj-$(CONFIG_TWL4030_WATCHDOG) += twl4030_wdt.o
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|  obj-$(CONFIG_21285_WATCHDOG) += wdt285.o
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|  obj-$(CONFIG_977_WATCHDOG) += wdt977.o
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| +obj-$(CONFIG_GEMINI_WATCHDOG) += gemini_wdt.o
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|  obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
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|  obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o
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|  obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o
 |