Release 4.7 drivers/watchdog/at91rm9200_wdt.c

Directory: drivers/watchdog
/*
 * Watchdog driver for Atmel AT91RM9200 (Thunder)
 *
 *  Copyright (C) 2003 SAN People (Pty) Ltd
 *
 * 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.
 */


#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>


#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="
				__MODULE_STRING(WDT_DEFAULT_TIME) ")");

#ifdef CONFIG_WATCHDOG_NOWAYOUT
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
#endif



static unsigned long at91wdt_busy;

/* ......................................................................... */



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;
}

Contributors
Person Tokens Prop Commits CommitProp
alexandre belloni alexandre belloni 55 100.00% 1 100.00%
Total 55 100.00% 1 100.00%


static struct notifier_block at91rm9200_restart_nb = {
	.notifier_call = at91rm9200_restart,
	.priority = 192,
};

/*
 * Disable the watchdog.
 */


static inline void at91_wdt_stop(void)
{
	regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN);
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 14 77.78% 1 33.33%
alexandre belloni alexandre belloni 3 16.67% 1 33.33%
alan cox alan cox 1 5.56% 1 33.33%
Total 18 100.00% 3 100.00%

/*
 * Enable and reset the watchdog.
 */


static inline void at91_wdt_start(void)
{
	regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
				(((65536 * wdt_time) >> 8) & AT91_ST_WDV));
	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 36 83.72% 1 33.33%
alexandre belloni alexandre belloni 6 13.95% 1 33.33%
alan cox alan cox 1 2.33% 1 33.33%
Total 43 100.00% 3 100.00%

/*
 * Reload the watchdog timer.  (ie, pat the watchdog)
 */


static inline void at91_wdt_reload(void)
{
	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 14 77.78% 1 33.33%
alexandre belloni alexandre belloni 3 16.67% 1 33.33%
alan cox alan cox 1 5.56% 1 33.33%
Total 18 100.00% 3 100.00%

/* ......................................................................... */

/*
 * Watchdog device is opened, and watchdog starts running.
 */


static int at91_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &at91wdt_busy))
		return -EBUSY;

	at91_wdt_start();
	return nonseekable_open(inode, file);
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 41 100.00% 1 100.00%
Total 41 100.00% 1 100.00%

/*
 * Close the watchdog device.
 * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also
 *  disabled.
 */


static int at91_wdt_close(struct inode *inode, struct file *file)
{
	/* Disable the watchdog when file is closed */
	if (!nowayout)
		at91_wdt_stop();

	clear_bit(0, &at91wdt_busy);
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 35 97.22% 1 50.00%
alan cox alan cox 1 2.78% 1 50.00%
Total 36 100.00% 2 100.00%

/*
 * Change the watchdog time interval.
 */


static int at91_wdt_settimeout(int new_time)
{
	/*
         * All counting occurs at SLOW_CLOCK / 128 = 256 Hz
         *
         * Since WDV is a 16-bit counter, the maximum period is
         * 65536 / 256 = 256 seconds.
         */
	if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
		return -EINVAL;

	/* Set new watchdog time. It will be used when
           at91_wdt_start() is called. */
	wdt_time = new_time;
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 35 97.22% 2 66.67%
alan cox alan cox 1 2.78% 1 33.33%
Total 36 100.00% 3 100.00%


static const struct watchdog_info at91_wdt_info = {
	.identity	= "at91 watchdog",
	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
};

/*
 * Handle commands from user-space.
 */


static long at91_wdt_ioctl(struct file *file,
					unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int new_value;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &at91_wdt_info,
				sizeof(at91_wdt_info)) ? -EFAULT : 0;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);
	case WDIOC_SETOPTIONS:
		if (get_user(new_value, p))
			return -EFAULT;
		if (new_value & WDIOS_DISABLECARD)
			at91_wdt_stop();
		if (new_value & WDIOS_ENABLECARD)
			at91_wdt_start();
		return 0;
	case WDIOC_KEEPALIVE:
		at91_wdt_reload();	/* pat the watchdog */
		return 0;
	case WDIOC_SETTIMEOUT:
		if (get_user(new_value, p))
			return -EFAULT;
		if (at91_wdt_settimeout(new_value))
			return -EINVAL;
		/* Enable new time value */
		at91_wdt_start();
		/* Return current value */
		return put_user(wdt_time, p);
	case WDIOC_GETTIMEOUT:
		return put_user(wdt_time, p);
	default:
		return -ENOTTY;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 124 66.67% 1 20.00%
wim van sebroeck wim van sebroeck 59 31.72% 1 20.00%
alan cox alan cox 1 0.54% 1 20.00%
adrian bunk adrian bunk 1 0.54% 1 20.00%
samuel tardieu samuel tardieu 1 0.54% 1 20.00%
Total 186 100.00% 5 100.00%

/*
 * Pat the watchdog whenever device is written to.
 */


static ssize_t at91_wdt_write(struct file *file, const char *data,
						size_t len, loff_t *ppos)
{
	at91_wdt_reload();		/* pat the watchdog */
	return len;
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%

/* ......................................................................... */


static const struct file_operations at91wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.unlocked_ioctl	= at91_wdt_ioctl,
	.open		= at91_wdt_open,
	.release	= at91_wdt_close,
	.write		= at91_wdt_write,
};


static struct miscdevice at91wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &at91wdt_fops,
};



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;
}

Contributors
Person Tokens Prop Commits CommitProp
alexandre belloni alexandre belloni 75 52.82% 2 28.57%
andrew victor andrew victor 63 44.37% 3 42.86%
bjorn andersson bjorn andersson 3 2.11% 1 14.29%
joe perches joe perches 1 0.70% 1 14.29%
Total 142 100.00% 7 100.00%



static int at91wdt_remove(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	int res;

	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;
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 31 53.45% 3 75.00%
alexandre belloni alexandre belloni 27 46.55% 1 25.00%
Total 58 100.00% 4 100.00%



static void at91wdt_shutdown(struct platform_device *pdev)
{
	at91_wdt_stop();
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%

#ifdef CONFIG_PM



static int at91wdt_suspend(struct platform_device *pdev, pm_message_t message)
{
	at91_wdt_stop();
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 20 100.00% 1 100.00%
Total 20 100.00% 1 100.00%



static int at91wdt_resume(struct platform_device *pdev)
{
	if (at91wdt_busy)
		at91_wdt_start();
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 21 100.00% 1 100.00%
Total 21 100.00% 1 100.00%

#else

#define at91wdt_suspend NULL

#define at91wdt_resume	NULL
#endif


static const struct of_device_id at91_wdt_dt_ids[] = {
	{ .compatible = "atmel,at91rm9200-wdt" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, at91_wdt_dt_ids);


static struct platform_driver at91wdt_driver = {
	.probe		= at91wdt_probe,
	.remove		= at91wdt_remove,
	.shutdown	= at91wdt_shutdown,
	.suspend	= at91wdt_suspend,
	.resume		= at91wdt_resume,
	.driver		= {
		.name	= "atmel_st_watchdog",
		.of_match_table = at91_wdt_dt_ids,
        },
};



static int __init at91_wdt_init(void)
{
	/* Check that the heartbeat value is within range;
           if not reset to the default */
	if (at91_wdt_settimeout(wdt_time)) {
		at91_wdt_settimeout(WDT_DEFAULT_TIME);
		pr_info("wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
			wdt_time);
	}

	return platform_driver_register(&at91wdt_driver);
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 36 94.74% 2 50.00%
joe perches joe perches 1 2.63% 1 25.00%
alan cox alan cox 1 2.63% 1 25.00%
Total 38 100.00% 4 100.00%



static void __exit at91_wdt_exit(void)
{
	platform_driver_unregister(&at91wdt_driver);
}

Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 15 100.00% 2 100.00%
Total 15 100.00% 2 100.00%


module_init(at91_wdt_init);

module_exit(at91_wdt_exit);

MODULE_AUTHOR("Andrew Victor");
MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:atmel_st_watchdog");
Overall Contributors
Person Tokens Prop Commits CommitProp
andrew victor andrew victor 808 70.44% 5 25.00%
alexandre belloni alexandre belloni 209 18.22% 2 10.00%
wim van sebroeck wim van sebroeck 62 5.41% 3 15.00%
joachim eastwood joachim eastwood 34 2.96% 1 5.00%
alan cox alan cox 9 0.78% 1 5.00%
joe perches joe perches 9 0.78% 1 5.00%
kay sievers kay sievers 4 0.35% 1 5.00%
jiri slaby jiri slaby 3 0.26% 1 5.00%
bjorn andersson bjorn andersson 3 0.26% 1 5.00%
jean-christophe plagniol-villard jean-christophe plagniol-villard 3 0.26% 1 5.00%
arjan van de ven arjan van de ven 1 0.09% 1 5.00%
adrian bunk adrian bunk 1 0.09% 1 5.00%
samuel tardieu samuel tardieu 1 0.09% 1 5.00%
Total 1147 100.00% 20 100.00%
  Directory: drivers/watchdog

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
	Person	Tokens	Prop	Commits	CommitProp
alexandre belloni	alexandre belloni	55	100.00%	1	100.00%
	Total	55	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.7 drivers/watchdog/at91rm9200_wdt.c

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Overall Contributors
