Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0b36086b authored by Jordan Crouse's avatar Jordan Crouse Committed by Wim Van Sebroeck
Browse files

[WATCHDOG] Add a watchdog driver based on the CS5535/CS5536 MFGPT timers 



Add a watchdog timer based on the MFGPT timers in the CS5535/CS5536
companion chips to the AMD Geode GX and LX processors.  Only caveat
is that the BIOS must provide at least a one free timer, and most
do not.

Signed-off-by: default avatarJordan Crouse <jordan.crouse@amd.com>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 7f7f894c

drivers/watchdog/Kconfig

+13 −0
Original line number Original line Diff line number Diff line
@@ -295,6 +295,19 @@ config ALIM7101_WDT 




	  Most people will say N.

	  Most people will say N.





config GEODE_WDT

	tristate "AMD Geode CS5535/CS5536 Watchdog"

	depends on MGEODE_LX

	help

	  This driver enables a watchdog capability built into the

	  CS5535/CS5536 companion chips for the AMD Geode GX and LX

	  processors.  This watchdog watches your kernel to make sure

	  it doesn't freeze, and if it does, it reboots your computer after

	  a certain amount of time.



	  You can compile this driver directly into the kernel, or use

	  it as a module.  The module will be called geodewdt.



config SC520_WDT

config SC520_WDT

	tristate "AMD Elan SC520 processor Watchdog"

	tristate "AMD Elan SC520 processor Watchdog"

	depends on X86

	depends on X86

drivers/watchdog/Makefile

+1 −0
Original line number Original line Diff line number Diff line
@@ -59,6 +59,7 @@ obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o 
obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o

obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o

obj-$(CONFIG_ALIM1535_WDT) += alim1535_wdt.o

obj-$(CONFIG_ALIM1535_WDT) += alim1535_wdt.o

obj-$(CONFIG_ALIM7101_WDT) += alim7101_wdt.o

obj-$(CONFIG_ALIM7101_WDT) += alim7101_wdt.o

obj-$(CONFIG_GEODE_WDT) += geodewdt.o

obj-$(CONFIG_SC520_WDT) += sc520_wdt.o

obj-$(CONFIG_SC520_WDT) += sc520_wdt.o

obj-$(CONFIG_EUROTECH_WDT) += eurotechwdt.o

obj-$(CONFIG_EUROTECH_WDT) += eurotechwdt.o

obj-$(CONFIG_IB700_WDT) += ib700wdt.o

obj-$(CONFIG_IB700_WDT) += ib700wdt.o

drivers/watchdog/geodewdt.c

0 → 100644
+309 −0
Original line number Original line Diff line number Diff line 
/* Watchdog timer for the Geode GX/LX with the CS5535/CS5536 companion chip

 *

 * Copyright (C) 2006-2007, Advanced Micro Devices, Inc.

 *

 * 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/moduleparam.h>

#include <linux/types.h>

#include <linux/miscdevice.h>

#include <linux/watchdog.h>

#include <linux/fs.h>

#include <linux/platform_device.h>

#include <linux/reboot.h>



#include <asm/uaccess.h>

#include <asm/geode.h>



#define GEODEWDT_HZ 500

#define GEODEWDT_SCALE 6

#define GEODEWDT_MAX_SECONDS 131



#define WDT_FLAGS_OPEN 1

#define WDT_FLAGS_ORPHAN 2



#define DRV_NAME "geodewdt"

#define WATCHDOG_NAME "Geode GX/LX WDT"

#define WATCHDOG_TIMEOUT 60



static int timeout = WATCHDOG_TIMEOUT;

module_param(timeout, int, 0);

MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=131, default=" __MODULE_STRING(WATCHDOG_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 struct platform_device *geodewdt_platform_device;

static unsigned long wdt_flags;

static int wdt_timer;

static int safe_close;



static void geodewdt_ping(void)

{

	/* Stop the counter */

	geode_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);



	/* Reset the counter */

	geode_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);



	/* Enable the counter */

	geode_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);

}



static void geodewdt_disable(void)

{

	geode_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);

	geode_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);

}



static int geodewdt_set_heartbeat(int val)

{

	if (val < 1 || val > GEODEWDT_MAX_SECONDS)

		return -EINVAL;



	geode_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);

	geode_mfgpt_write(wdt_timer, MFGPT_REG_CMP2, val * GEODEWDT_HZ);

	geode_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);

	geode_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);



	timeout = val;

	return 0;

}



static int

geodewdt_open(struct inode *inode, struct file *file)

{

        if (test_and_set_bit(WDT_FLAGS_OPEN, &wdt_flags))

                return -EBUSY;



        if (!test_and_clear_bit(WDT_FLAGS_ORPHAN, &wdt_flags))

                __module_get(THIS_MODULE);



	geodewdt_ping();

        return nonseekable_open(inode, file);

}



static int

geodewdt_release(struct inode *inode, struct file *file)

{

	if (safe_close) {

		geodewdt_disable();

		module_put(THIS_MODULE);

	}

	else {

		printk(KERN_CRIT "Unexpected close - watchdog is not stopping.\n");

		geodewdt_ping();



		set_bit(WDT_FLAGS_ORPHAN, &wdt_flags);

	}



	clear_bit(WDT_FLAGS_OPEN, &wdt_flags);

	safe_close = 0;

	return 0;

}



static ssize_t

geodewdt_write(struct file *file, const char __user *data, size_t len,

	       loff_t *ppos)

{

        if(len) {

		if (!nowayout) {

			size_t i;

			safe_close = 0;



			for (i = 0; i != len; i++) {

				char c;



				if (get_user(c, data + i))

					return -EFAULT;



				if (c == 'V')

					safe_close = 1;

			}

		}



		geodewdt_ping();

	}

	return len;

}



static int

geodewdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,

	       unsigned long arg)

{

	void __user *argp = (void __user *)arg;

	int __user *p = argp;

	int interval;



	static struct watchdog_info ident = {

		.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING

		| WDIOF_MAGICCLOSE,

		.firmware_version =     1,

		.identity =             WATCHDOG_NAME,

        };



	switch(cmd) {

	case WDIOC_GETSUPPORT:

		return copy_to_user(argp, &ident,

				    sizeof(ident)) ? -EFAULT : 0;

		break;



	case WDIOC_GETSTATUS:

	case WDIOC_GETBOOTSTATUS:

		return put_user(0, p);



	case WDIOC_KEEPALIVE:

		geodewdt_ping();

		return 0;



	case WDIOC_SETTIMEOUT:

		if (get_user(interval, p))

			return -EFAULT;



		if (geodewdt_set_heartbeat(interval))

			return -EINVAL;



/* Fall through */



	case WDIOC_GETTIMEOUT:

		return put_user(timeout, p);



	case WDIOC_SETOPTIONS:

	{

		int options, ret = -EINVAL;



		if (get_user(options, p))

			return -EFAULT;



		if (options & WDIOS_DISABLECARD) {

			geodewdt_disable();

			ret = 0;

		}



		if (options & WDIOS_ENABLECARD) {

			geodewdt_ping();

			ret = 0;

		}



		return ret;

	}

	default:

		return -ENOTTY;

	}



	return 0;

}



static const struct file_operations geodewdt_fops = {

        .owner          = THIS_MODULE,

        .llseek         = no_llseek,

        .write          = geodewdt_write,

        .ioctl          = geodewdt_ioctl,

        .open           = geodewdt_open,

        .release        = geodewdt_release,

};



static struct miscdevice geodewdt_miscdev = {

	.minor = WATCHDOG_MINOR,

	.name = "watchdog",

	.fops = &geodewdt_fops

};



static int __devinit

geodewdt_probe(struct platform_device *dev)

{

	int ret, timer;



	timer = geode_mfgpt_alloc_timer(MFGPT_TIMER_ANY,

					MFGPT_DOMAIN_WORKING, THIS_MODULE);



	if (timer == -1) {

		printk(KERN_ERR "geodewdt:  No timers were available\n");

		return -ENODEV;

	}



	wdt_timer = timer;



	/* Set up the timer */



	geode_mfgpt_write(wdt_timer, MFGPT_REG_SETUP,

			  GEODEWDT_SCALE | (3 << 8));



	/* Set up comparator 2 to reset when the event fires */

	geode_mfgpt_toggle_event(wdt_timer, MFGPT_CMP2, MFGPT_EVENT_RESET, 1);



	/* Set up the initial timeout */



	geode_mfgpt_write(wdt_timer, MFGPT_REG_CMP2,

		timeout * GEODEWDT_HZ);



	ret = misc_register(&geodewdt_miscdev);



	return ret;

}



static int __devexit

geodewdt_remove(struct platform_device *dev)

{

	misc_deregister(&geodewdt_miscdev);

	return 0;

}



static void

geodewdt_shutdown(struct platform_device *dev)

{

	geodewdt_disable();

}



static struct platform_driver geodewdt_driver = {

	.probe		= geodewdt_probe,

	.remove		= __devexit_p(geodewdt_remove),

	.shutdown	= geodewdt_shutdown,

	.driver		= {

		.owner	= THIS_MODULE,

		.name	= DRV_NAME,

	},

};



static int __init

geodewdt_init(void)

{

	int ret;



	ret = platform_driver_register(&geodewdt_driver);

	if (ret)

		return ret;



	geodewdt_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0);

	if (IS_ERR(geodewdt_platform_device)) {

		ret = PTR_ERR(geodewdt_platform_device);

		goto err;

	}



	return 0;

err:

	platform_driver_unregister(&geodewdt_driver);

	return ret;

}



static void __exit

geodewdt_exit(void)

{

	platform_device_unregister(geodewdt_platform_device);

	platform_driver_unregister(&geodewdt_driver);

}



module_init(geodewdt_init);

module_exit(geodewdt_exit);



MODULE_AUTHOR("Advanced Micro Devices, Inc");

MODULE_DESCRIPTION("Geode GX/LX Watchdog Driver");

MODULE_LICENSE("GPL");

MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);