drivers/watchdog/rc32434_wdt.c - kernel/msm - Gitiles

 /*
  *  IDT Interprise 79RC32434 watchdog driver
  *
  *  Copyright (C) 2006, Ondrej Zajicek <santiago@crfreenet.org>
  *  Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
  *
  *  based on
  *  SoftDog 0.05:	A Software Watchdog Device
  *
  *  (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
  *					All Rights Reserved.
  *
  *  This program is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU General Public License
  *  as published by the Free Software Foundation; either version
  *  2 of the License, or (at your option) any later version.
  *
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/miscdevice.h>
 #include <linux/watchdog.h>
 #include <linux/reboot.h>
 #include <linux/smp_lock.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/uaccess.h>

 #include <asm/bootinfo.h>
 #include <asm/time.h>
 #include <asm/mach-rc32434/integ.h>

 #define MAX_TIMEOUT			20
 #define RC32434_WDT_INTERVAL		(15 * HZ)

 #define VERSION "0.2"

 static struct {
 	struct completion stop;
 	int running;
 	struct timer_list timer;
 	int queue;
 	int default_ticks;
 	unsigned long inuse;
 } rc32434_wdt_device;

 static struct integ __iomem *wdt_reg;
 static int ticks = 100 * HZ;

 static int expect_close;
 static int timeout;

 static int nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, int, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");


 static void rc32434_wdt_start(void)
 {
 	u32 val;

 	if (!rc32434_wdt_device.inuse) {
 		writel(0, &wdt_reg->wtcount);

 		val = RC32434_ERR_WRE;
 		writel(readl(&wdt_reg->errcs) | val, &wdt_reg->errcs);

 		val = RC32434_WTC_EN;
 		writel(readl(&wdt_reg->wtc) | val, &wdt_reg->wtc);
 	}
 	rc32434_wdt_device.running++;
 }

 static void rc32434_wdt_stop(void)
 {
 	u32 val;

 	if (rc32434_wdt_device.running) {

 		val = ~RC32434_WTC_EN;
 		writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);

 		val = ~RC32434_ERR_WRE;
 		writel(readl(&wdt_reg->errcs) & val, &wdt_reg->errcs);

 		rc32434_wdt_device.running = 0;
 	}
 }

 static void rc32434_wdt_set(int new_timeout)
 {
 	u32 cmp = new_timeout * HZ;
 	u32 state, val;

 	timeout = new_timeout;
 	/*
 	 * store and disable WTC
 	 */
 	state = (u32)(readl(&wdt_reg->wtc) & RC32434_WTC_EN);
 	val = ~RC32434_WTC_EN;
 	writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);

 	writel(0, &wdt_reg->wtcount);
 	writel(cmp, &wdt_reg->wtcompare);

 	/*
 	 * restore WTC
 	 */

 	writel(readl(&wdt_reg->wtc) | state, &wdt_reg);
 }

 static void rc32434_wdt_reset(void)
 {
 	ticks = rc32434_wdt_device.default_ticks;
 }

 static void rc32434_wdt_update(unsigned long unused)
 {
 	if (rc32434_wdt_device.running)
 		ticks--;

 	writel(0, &wdt_reg->wtcount);

 	if (rc32434_wdt_device.queue && ticks)
 		mod_timer(&rc32434_wdt_device.timer,
 			jiffies + RC32434_WDT_INTERVAL);
 	else
 		complete(&rc32434_wdt_device.stop);
 }

 static int rc32434_wdt_open(struct inode *inode, struct file *file)
 {
 	if (test_and_set_bit(0, &rc32434_wdt_device.inuse))
 		return -EBUSY;

 	if (nowayout)
 		__module_get(THIS_MODULE);

 	return nonseekable_open(inode, file);
 }

 static int rc32434_wdt_release(struct inode *inode, struct file *file)
 {
 	if (expect_close && nowayout == 0) {
 		rc32434_wdt_stop();
 		printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n");
 		module_put(THIS_MODULE);
 	} else
 		printk(KERN_CRIT KBUILD_MODNAME
 			": device closed unexpectedly. WDT will not stop !\n");

 	clear_bit(0, &rc32434_wdt_device.inuse);
 	return 0;
 }

 static ssize_t rc32434_wdt_write(struct file *file, const char *data,
 				size_t len, loff_t *ppos)
 {
 	if (len) {
 		if (!nowayout) {
 			size_t i;

 			/* In case it was set long ago */
 			expect_close = 0;

 			for (i = 0; i != len; i++) {
 				char c;
 				if (get_user(c, data + i))
 					return -EFAULT;
 				if (c == 'V')
 					expect_close = 1;
 			}
 		}
 		rc32434_wdt_update(0);
 		return len;
 	}
 	return 0;
 }

 static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
 				unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	int new_timeout;
 	unsigned int value;
 	static struct watchdog_info ident = {
 		.options =		WDIOF_SETTIMEOUT |
 					WDIOF_KEEPALIVEPING |
 					WDIOF_MAGICCLOSE,
 		.identity =		"RC32434_WDT Watchdog",
 	};
 	switch (cmd) {
 	case WDIOC_KEEPALIVE:
 		rc32434_wdt_reset();
 		break;
 	case WDIOC_GETSTATUS:
 	case WDIOC_GETBOOTSTATUS:
 		value = readl(&wdt_reg->wtcount);
 		if (copy_to_user(argp, &value, sizeof(int)))
 			return -EFAULT;
 		break;
 	case WDIOC_GETSUPPORT:
 		if (copy_to_user(argp, &ident, sizeof(ident)))
 			return -EFAULT;
 		break;
 	case WDIOC_SETOPTIONS:
 		if (copy_from_user(&value, argp, sizeof(int)))
 			return -EFAULT;
 		switch (value) {
 		case WDIOS_ENABLECARD:
 			rc32434_wdt_start();
 			break;
 		case WDIOS_DISABLECARD:
 			rc32434_wdt_stop();
 		default:
 			return -EINVAL;
 		}
 		break;
 	case WDIOC_SETTIMEOUT:
 		if (copy_from_user(&new_timeout, argp, sizeof(int)))
 			return -EFAULT;
 		if (new_timeout < 1)
 			return -EINVAL;
 		if (new_timeout > MAX_TIMEOUT)
 			return -EINVAL;
 		rc32434_wdt_set(new_timeout);
 	case WDIOC_GETTIMEOUT:
 		return copy_to_user(argp, &timeout, sizeof(int));
 	default:
 		return -ENOTTY;
 	}

 	return 0;
 }

 static struct file_operations rc32434_wdt_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.write		= rc32434_wdt_write,
 	.unlocked_ioctl	= rc32434_wdt_ioctl,
 	.open		= rc32434_wdt_open,
 	.release	= rc32434_wdt_release,
 };

 static struct miscdevice rc32434_wdt_miscdev = {
 	.minor	= WATCHDOG_MINOR,
 	.name	= "watchdog",
 	.fops	= &rc32434_wdt_fops,
 };

 static char banner[] = KERN_INFO KBUILD_MODNAME
 		": Watchdog Timer version " VERSION ", timer margin: %d sec\n";

 static int rc32434_wdt_probe(struct platform_device *pdev)
 {
 	int ret;
 	struct resource *r;

 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb500_wdt_res");
 	if (!r) {
 		printk(KERN_ERR KBUILD_MODNAME
 			"failed to retrieve resources\n");
 		return -ENODEV;
 	}

 	wdt_reg = ioremap_nocache(r->start, r->end - r->start);
 	if (!wdt_reg) {
 		printk(KERN_ERR KBUILD_MODNAME
 			"failed to remap I/O resources\n");
 		return -ENXIO;
 	}

 	ret = misc_register(&rc32434_wdt_miscdev);

 	if (ret < 0) {
 		printk(KERN_ERR KBUILD_MODNAME
 			"failed to register watchdog device\n");
 		goto unmap;
 	}

 	init_completion(&rc32434_wdt_device.stop);
 	rc32434_wdt_device.queue = 0;

 	clear_bit(0, &rc32434_wdt_device.inuse);

 	setup_timer(&rc32434_wdt_device.timer, rc32434_wdt_update, 0L);

 	rc32434_wdt_device.default_ticks = ticks;

 	rc32434_wdt_start();

 	printk(banner, timeout);

 	return 0;

 unmap:
 	iounmap(wdt_reg);
 	return ret;
 }

 static int rc32434_wdt_remove(struct platform_device *pdev)
 {
 	if (rc32434_wdt_device.queue) {
 		rc32434_wdt_device.queue = 0;
 		wait_for_completion(&rc32434_wdt_device.stop);
 	}
 	misc_deregister(&rc32434_wdt_miscdev);

 	iounmap(wdt_reg);

 	return 0;
 }

 static struct platform_driver rc32434_wdt = {
 	.probe	= rc32434_wdt_probe,
 	.remove = rc32434_wdt_remove,
 	.driver = {
 		.name = "rc32434_wdt",
 	}
 };

 static int __init rc32434_wdt_init(void)
 {
 	return platform_driver_register(&rc32434_wdt);
 }

 static void __exit rc32434_wdt_exit(void)
 {
 	platform_driver_unregister(&rc32434_wdt);
 }

 module_init(rc32434_wdt_init);
 module_exit(rc32434_wdt_exit);

 MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>,"
 		"Florian Fainelli <florian@openwrt.org>");
 MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	/*
	* IDT Interprise 79RC32434 watchdog driver
	*
	* Copyright (C) 2006, Ondrej Zajicek <santiago@crfreenet.org>
	* Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
	*
	* based on
	* SoftDog 0.05: A Software Watchdog Device
	*
	* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
	* All Rights Reserved.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/fs.h>
	#include <linux/mm.h>
	#include <linux/miscdevice.h>
	#include <linux/watchdog.h>
	#include <linux/reboot.h>
	#include <linux/smp_lock.h>
	#include <linux/init.h>
	#include <linux/platform_device.h>
	#include <linux/uaccess.h>

	#include <asm/bootinfo.h>
	#include <asm/time.h>
	#include <asm/mach-rc32434/integ.h>

	#define MAX_TIMEOUT 20
	#define RC32434_WDT_INTERVAL (15 * HZ)

	#define VERSION "0.2"

	static struct {
	struct completion stop;
	int running;
	struct timer_list timer;
	int queue;
	int default_ticks;
	unsigned long inuse;
	} rc32434_wdt_device;

	static struct integ __iomem *wdt_reg;
	static int ticks = 100 * HZ;

	static int expect_close;
	static int timeout;

	static int nowayout = WATCHDOG_NOWAYOUT;
	module_param(nowayout, int, 0);
	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");


	static void rc32434_wdt_start(void)
	{
	u32 val;

	if (!rc32434_wdt_device.inuse) {
	writel(0, &wdt_reg->wtcount);

	val = RC32434_ERR_WRE;
	writel(readl(&wdt_reg->errcs) \| val, &wdt_reg->errcs);

	val = RC32434_WTC_EN;
	writel(readl(&wdt_reg->wtc) \| val, &wdt_reg->wtc);
	}
	rc32434_wdt_device.running++;
	}

	static void rc32434_wdt_stop(void)
	{
	u32 val;

	if (rc32434_wdt_device.running) {

	val = ~RC32434_WTC_EN;
	writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);

	val = ~RC32434_ERR_WRE;
	writel(readl(&wdt_reg->errcs) & val, &wdt_reg->errcs);

	rc32434_wdt_device.running = 0;
	}
	}

	static void rc32434_wdt_set(int new_timeout)
	{
	u32 cmp = new_timeout * HZ;
	u32 state, val;

	timeout = new_timeout;
	/*
	* store and disable WTC
	*/
	state = (u32)(readl(&wdt_reg->wtc) & RC32434_WTC_EN);
	val = ~RC32434_WTC_EN;
	writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);

	writel(0, &wdt_reg->wtcount);
	writel(cmp, &wdt_reg->wtcompare);

	/*
	* restore WTC
	*/

	writel(readl(&wdt_reg->wtc) \| state, &wdt_reg);
	}

	static void rc32434_wdt_reset(void)
	{
	ticks = rc32434_wdt_device.default_ticks;
	}

	static void rc32434_wdt_update(unsigned long unused)
	{
	if (rc32434_wdt_device.running)
	ticks--;

	writel(0, &wdt_reg->wtcount);

	if (rc32434_wdt_device.queue && ticks)
	mod_timer(&rc32434_wdt_device.timer,
	jiffies + RC32434_WDT_INTERVAL);
	else
	complete(&rc32434_wdt_device.stop);
	}

	static int rc32434_wdt_open(struct inode inode, struct file file)
	{
	if (test_and_set_bit(0, &rc32434_wdt_device.inuse))
	return -EBUSY;

	if (nowayout)
	__module_get(THIS_MODULE);

	return nonseekable_open(inode, file);
	}

	static int rc32434_wdt_release(struct inode inode, struct file file)
	{
	if (expect_close && nowayout == 0) {
	rc32434_wdt_stop();
	printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n");
	module_put(THIS_MODULE);
	} else
	printk(KERN_CRIT KBUILD_MODNAME
	": device closed unexpectedly. WDT will not stop !\n");

	clear_bit(0, &rc32434_wdt_device.inuse);
	return 0;
	}

	static ssize_t rc32434_wdt_write(struct file file, const char data,
	size_t len, loff_t *ppos)
	{
	if (len) {
	if (!nowayout) {
	size_t i;

	/* In case it was set long ago */
	expect_close = 0;

	for (i = 0; i != len; i++) {
	char c;
	if (get_user(c, data + i))
	return -EFAULT;
	if (c == 'V')
	expect_close = 1;
	}
	}
	rc32434_wdt_update(0);
	return len;
	}
	return 0;
	}

	static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	void __user argp = (void __user )arg;
	int new_timeout;
	unsigned int value;
	static struct watchdog_info ident = {
	.options = WDIOF_SETTIMEOUT \|
	WDIOF_KEEPALIVEPING \|
	WDIOF_MAGICCLOSE,
	.identity = "RC32434_WDT Watchdog",
	};
	switch (cmd) {
	case WDIOC_KEEPALIVE:
	rc32434_wdt_reset();
	break;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
	value = readl(&wdt_reg->wtcount);
	if (copy_to_user(argp, &value, sizeof(int)))
	return -EFAULT;
	break;
	case WDIOC_GETSUPPORT:
	if (copy_to_user(argp, &ident, sizeof(ident)))
	return -EFAULT;
	break;
	case WDIOC_SETOPTIONS:
	if (copy_from_user(&value, argp, sizeof(int)))
	return -EFAULT;
	switch (value) {
	case WDIOS_ENABLECARD:
	rc32434_wdt_start();
	break;
	case WDIOS_DISABLECARD:
	rc32434_wdt_stop();
	default:
	return -EINVAL;
	}
	break;
	case WDIOC_SETTIMEOUT:
	if (copy_from_user(&new_timeout, argp, sizeof(int)))
	return -EFAULT;
	if (new_timeout < 1)
	return -EINVAL;
	if (new_timeout > MAX_TIMEOUT)
	return -EINVAL;
	rc32434_wdt_set(new_timeout);
	case WDIOC_GETTIMEOUT:
	return copy_to_user(argp, &timeout, sizeof(int));
	default:
	return -ENOTTY;
	}

	return 0;
	}

	static struct file_operations rc32434_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = rc32434_wdt_write,
	.unlocked_ioctl = rc32434_wdt_ioctl,
	.open = rc32434_wdt_open,
	.release = rc32434_wdt_release,
	};

	static struct miscdevice rc32434_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &rc32434_wdt_fops,
	};

	static char banner[] = KERN_INFO KBUILD_MODNAME
	": Watchdog Timer version " VERSION ", timer margin: %d sec\n";

	static int rc32434_wdt_probe(struct platform_device *pdev)
	{
	int ret;
	struct resource *r;

	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb500_wdt_res");
	if (!r) {
	printk(KERN_ERR KBUILD_MODNAME
	"failed to retrieve resources\n");
	return -ENODEV;
	}

	wdt_reg = ioremap_nocache(r->start, r->end - r->start);
	if (!wdt_reg) {
	printk(KERN_ERR KBUILD_MODNAME
	"failed to remap I/O resources\n");
	return -ENXIO;
	}

	ret = misc_register(&rc32434_wdt_miscdev);

	if (ret < 0) {
	printk(KERN_ERR KBUILD_MODNAME
	"failed to register watchdog device\n");
	goto unmap;
	}

	init_completion(&rc32434_wdt_device.stop);
	rc32434_wdt_device.queue = 0;

	clear_bit(0, &rc32434_wdt_device.inuse);

	setup_timer(&rc32434_wdt_device.timer, rc32434_wdt_update, 0L);

	rc32434_wdt_device.default_ticks = ticks;

	rc32434_wdt_start();

	printk(banner, timeout);

	return 0;

	unmap:
	iounmap(wdt_reg);
	return ret;
	}

	static int rc32434_wdt_remove(struct platform_device *pdev)
	{
	if (rc32434_wdt_device.queue) {
	rc32434_wdt_device.queue = 0;
	wait_for_completion(&rc32434_wdt_device.stop);
	}
	misc_deregister(&rc32434_wdt_miscdev);

	iounmap(wdt_reg);

	return 0;
	}

	static struct platform_driver rc32434_wdt = {
	.probe = rc32434_wdt_probe,
	.remove = rc32434_wdt_remove,
	.driver = {
	.name = "rc32434_wdt",
	}
	};

	static int __init rc32434_wdt_init(void)
	{
	return platform_driver_register(&rc32434_wdt);
	}

	static void __exit rc32434_wdt_exit(void)
	{
	platform_driver_unregister(&rc32434_wdt);
	}

	module_init(rc32434_wdt_init);
	module_exit(rc32434_wdt_exit);

	MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>,"
	"Florian Fainelli <florian@openwrt.org>");
	MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);