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Commit 825d3748 authored by Thomas Koeller's avatar Thomas Koeller Committed by Wim Van Sebroeck
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[WATCHDOG] MIPS RM9000 on-chip watchdog device 



This is a driver for the on-chip watchdog device found on some
MIPS RM9000 processors.

Signed-off-by: default avatarThomas Koeller <thomas.koeller@baslerweb.com>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent e033351d

drivers/char/watchdog/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -575,6 +575,16 @@ config INDYDOG 
	  timer expired and no process has written to /dev/watchdog during

	  that time.



config WDT_RM9K_GPI

	tristate "RM9000/GPI hardware watchdog"

	depends on WATCHDOG && CPU_RM9000

	help

	  Watchdog implementation using the GPI hardware found on

	  PMC-Sierra RM9xxx CPUs.



	  To compile this driver as a module, choose M here: the

	  module will be called rm9k_wdt.



# S390 Architecture



config ZVM_WATCHDOG

drivers/char/watchdog/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o 


# MIPS Architecture

obj-$(CONFIG_INDYDOG) += indydog.o

obj-$(CONFIG_WDT_RM9K_GPI) += rm9k_wdt.o



# S390 Architecture

drivers/char/watchdog/rm9k_wdt.c

0 → 100644
+431 −0
Original line number Diff line number Diff line 
/*

 *  Watchdog implementation for GPI h/w found on PMC-Sierra RM9xxx

 *  chips.

 *

 *  Copyright (C) 2004 by Basler Vision Technologies AG

 *  Author: Thomas Koeller <thomas.koeller@baslerweb.com>

 *

 *  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.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */



#include <linux/platform_device.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/interrupt.h>

#include <linux/fs.h>

#include <linux/reboot.h>

#include <linux/miscdevice.h>

#include <linux/watchdog.h>

#include <asm/io.h>

#include <asm/atomic.h>

#include <asm/processor.h>

#include <asm/uaccess.h>

#include <asm/system.h>

#include <asm/rm9k-ocd.h>



#include <rm9k_wdt.h>





#define CLOCK                  125000000

#define MAX_TIMEOUT_SECONDS    32

#define CPCCR                  0x0080

#define CPGIG1SR               0x0044

#define CPGIG1ER               0x0054







/* Function prototypes */

static int __init wdt_gpi_probe(struct device *);

static int __exit wdt_gpi_remove(struct device *);

static void wdt_gpi_set_timeout(unsigned int);

static int wdt_gpi_open(struct inode *, struct file *);

static int wdt_gpi_release(struct inode *, struct file *);

static ssize_t wdt_gpi_write(struct file *, const char __user *, size_t, loff_t *);

static long wdt_gpi_ioctl(struct file *, unsigned int, unsigned long);

static const struct resource *wdt_gpi_get_resource(struct platform_device *, const char *, unsigned int);

static int wdt_gpi_notify(struct notifier_block *, unsigned long, void *);

static irqreturn_t wdt_gpi_irqhdl(int, void *, struct pt_regs *);









static const char wdt_gpi_name[] = "wdt_gpi";

static atomic_t opencnt;

static int expect_close;

static int locked = 0;







/* These are set from device resources */

static void __iomem * wd_regs;

static unsigned int wd_irq, wd_ctr;







/* Module arguments */

static int timeout = MAX_TIMEOUT_SECONDS;

module_param(timeout, int, 0444);

static unsigned long resetaddr = 0xbffdc200;

module_param(resetaddr, ulong, 0444);

static unsigned long flagaddr = 0xbffdc104;

module_param(flagaddr, ulong, 0444);

static int powercycle = 0;

module_param(powercycle, bool, 0444);



static int nowayout = WATCHDOG_NOWAYOUT;

module_param(nowayout, bool, 0444);







static struct file_operations fops = {

	.owner		= THIS_MODULE,

	.open		= wdt_gpi_open,

	.release	= wdt_gpi_release,

	.write		= wdt_gpi_write,

	.unlocked_ioctl	= wdt_gpi_ioctl,

};



static struct miscdevice miscdev = {

	.minor		= WATCHDOG_MINOR,

	.name		= wdt_gpi_name,

	.fops		= &fops,

};



static struct device_driver wdt_gpi_driver = {

	.name		= (char *) wdt_gpi_name,

	.bus		= &platform_bus_type,

	.owner		= THIS_MODULE,

	.probe		= wdt_gpi_probe,

	.remove		= __exit_p(wdt_gpi_remove),

	.shutdown	= NULL,

	.suspend	= NULL,

	.resume		= NULL,

};



static struct notifier_block wdt_gpi_shutdown = {

	.notifier_call	= wdt_gpi_notify,

};







static const struct resource *

wdt_gpi_get_resource(struct platform_device *pdv, const char *name,

		      unsigned int type)

{

	char buf[80];

	if (snprintf(buf, sizeof buf, "%s_0", name) >= sizeof buf)

		return NULL;

	return platform_get_resource_byname(pdv, type, buf);

}







/* No hotplugging on the platform bus - use __init */

static int __init wdt_gpi_probe(struct device *dev)

{

	int res;

	struct platform_device * const pdv = to_platform_device(dev);

	const struct resource

		* const rr = wdt_gpi_get_resource(pdv, WDT_RESOURCE_REGS,

						  IORESOURCE_MEM),

		* const ri = wdt_gpi_get_resource(pdv, WDT_RESOURCE_IRQ,

						  IORESOURCE_IRQ),

		* const rc = wdt_gpi_get_resource(pdv, WDT_RESOURCE_COUNTER,

						  0);



	if (unlikely(!rr || !ri || !rc))

		return -ENXIO;



	wd_regs = ioremap_nocache(rr->start, rr->end + 1 - rr->start);

	if (unlikely(!wd_regs))

		return -ENOMEM;

	wd_irq = ri->start;

	wd_ctr = rc->start;

	res = misc_register(&miscdev);

	if (res)

		iounmap(wd_regs);

	else

		register_reboot_notifier(&wdt_gpi_shutdown);

	return res;

}







static int __exit wdt_gpi_remove(struct device *dev)

{

	int res;



	unregister_reboot_notifier(&wdt_gpi_shutdown);

	res = misc_deregister(&miscdev);

	iounmap(wd_regs);

	wd_regs = NULL;

	return res;

}





static void wdt_gpi_set_timeout(unsigned int to)

{

	u32 reg;

	const u32 wdval = (to * CLOCK) & ~0x0000000f;



	lock_titan_regs();

	reg = titan_readl(CPCCR) & ~(0xf << (wd_ctr * 4));

	titan_writel(reg, CPCCR);

	wmb();

	__raw_writel(wdval, wd_regs + 0x0000);

	wmb();

	titan_writel(reg | (0x2 << (wd_ctr * 4)), CPCCR);

	wmb();

	titan_writel(reg | (0x5 << (wd_ctr * 4)), CPCCR);

	iob();

	unlock_titan_regs();

}







static int wdt_gpi_open(struct inode *i, struct file *f)

{

	int res;

	u32 reg;



	if (unlikely(0 > atomic_dec_if_positive(&opencnt)))

		return -EBUSY;



	expect_close = 0;

	if (locked) {

		module_put(THIS_MODULE);

		free_irq(wd_irq, &miscdev);

		locked = 0;

	}



	res = request_irq(wd_irq, wdt_gpi_irqhdl, SA_SHIRQ | SA_INTERRUPT,

			  wdt_gpi_name, &miscdev);

	if (unlikely(res))

		return res;



	wdt_gpi_set_timeout(timeout);



	lock_titan_regs();

	reg = titan_readl(CPGIG1ER);

	titan_writel(reg | (0x100 << wd_ctr), CPGIG1ER);

	iob();

	unlock_titan_regs();



	printk(KERN_INFO "%s: watchdog started, timeout = %u seconds\n",

		wdt_gpi_name, timeout);

	return 0;

}







static int wdt_gpi_release(struct inode *i, struct file *f)

{

	if (nowayout) {

		printk(KERN_NOTICE "%s: no way out - watchdog left running\n",

			wdt_gpi_name);

		__module_get(THIS_MODULE);

		locked = 1;

	} else {

		if (expect_close) {

			u32 reg;



			lock_titan_regs();

			reg = titan_readl(CPCCR) & ~(0xf << (wd_ctr * 4));

			titan_writel(reg, CPCCR);

			reg = titan_readl(CPGIG1ER);

			titan_writel(reg & ~(0x100 << wd_ctr), CPGIG1ER);

			iob();

			unlock_titan_regs();

			free_irq(wd_irq, &miscdev);

			printk(KERN_INFO "%s: watchdog stopped\n", wdt_gpi_name);

		} else {

			printk(KERN_NOTICE "%s: unexpected close() -"

				" watchdog left running\n",

				wdt_gpi_name);

			wdt_gpi_set_timeout(timeout);

			__module_get(THIS_MODULE);

			locked = 1;

		}

	}



	atomic_inc(&opencnt);

	return 0;

}







static ssize_t

wdt_gpi_write(struct file *f, const char __user *d, size_t s, loff_t *o)

{

	char val;



	wdt_gpi_set_timeout(timeout);

	expect_close = (s > 0) && !get_user(val, d) && (val == 'V');

	return s ? 1 : 0;

}







static long

wdt_gpi_ioctl(struct file *f, unsigned int cmd, unsigned long arg)

{

	long res = -ENOTTY;

	const long size = _IOC_SIZE(cmd);

	int stat;

	static struct watchdog_info wdinfo = {

		.identity               = "RM9xxx/GPI watchdog",

		.firmware_version       = 0,

		.options                = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING

	};



	if (unlikely(_IOC_TYPE(cmd) != WATCHDOG_IOCTL_BASE))

		return -ENOTTY;



	if ((_IOC_DIR(cmd) & _IOC_READ)

	    && !access_ok(VERIFY_WRITE, arg, size))

		return -EFAULT;



	if ((_IOC_DIR(cmd) & _IOC_WRITE)

	    && !access_ok(VERIFY_READ, arg, size))

		return -EFAULT;



	expect_close = 0;



	switch (cmd) {

	case WDIOC_GETSUPPORT:

		wdinfo.options = nowayout ?

			WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING :

			WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE;

		res = __copy_to_user((void __user *)arg, &wdinfo, size) ?

			-EFAULT : size;

		break;



	case WDIOC_GETSTATUS:

		break;



	case WDIOC_GETBOOTSTATUS:

		stat = (*(volatile char *) flagaddr & 0x01)

			? WDIOF_CARDRESET : 0;

		res = __copy_to_user((void __user *)arg, &stat, size) ?

			-EFAULT : size;

		break;



	case WDIOC_SETOPTIONS:

		break;



	case WDIOC_KEEPALIVE:

		wdt_gpi_set_timeout(timeout);

		res = size;

		break;



	case WDIOC_SETTIMEOUT:

		{

			int val;

			if (unlikely(__copy_from_user(&val, (const void __user *) arg,

					size))) {

				res = -EFAULT;

				break;

			}



			if (val > 32)

				val = 32;

			timeout = val;

			wdt_gpi_set_timeout(val);

			res = size;

			printk("%s: timeout set to %u seconds\n",

				wdt_gpi_name, timeout);

		}

		break;



	case WDIOC_GETTIMEOUT:

		res = __copy_to_user((void __user *) arg, &timeout, size) ?

			-EFAULT : size;

		break;

	}



	return res;

}









static irqreturn_t wdt_gpi_irqhdl(int irq, void *ctxt, struct pt_regs *regs)

{

	if (!unlikely(__raw_readl(wd_regs + 0x0008) & 0x1))

		return IRQ_NONE;

	__raw_writel(0x1, wd_regs + 0x0008);





	printk(KERN_WARNING "%s: watchdog expired - resetting system\n",

		wdt_gpi_name);



	*(volatile char *) flagaddr |= 0x01;

	*(volatile char *) resetaddr = powercycle ? 0x01 : 0x2;

	iob();

	while (1)

		cpu_relax();

}







static int

wdt_gpi_notify(struct notifier_block *this, unsigned long code, void *unused)

{

	if(code == SYS_DOWN || code == SYS_HALT) {

		u32 reg;



		lock_titan_regs();

		reg = titan_readl(CPCCR) & ~(0xf << (wd_ctr * 4));

		titan_writel(reg, CPCCR);

		reg = titan_readl(CPGIG1ER);

		titan_writel(reg & ~(0x100 << wd_ctr), CPGIG1ER);

		iob();

		unlock_titan_regs();

	}

	return NOTIFY_DONE;

}







static int __init wdt_gpi_init_module(void)

{

	atomic_set(&opencnt, 1);

	if (timeout > MAX_TIMEOUT_SECONDS)

		timeout = MAX_TIMEOUT_SECONDS;

	return driver_register(&wdt_gpi_driver);

}







static void __exit wdt_gpi_cleanup_module(void)

{

	driver_unregister(&wdt_gpi_driver);

}



module_init(wdt_gpi_init_module);

module_exit(wdt_gpi_cleanup_module);







MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");

MODULE_DESCRIPTION("Basler eXcite watchdog driver for gpi devices");

MODULE_VERSION("0.1");

MODULE_LICENSE("GPL");

MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");

MODULE_PARM_DESC(resetaddr, "Address to write to to force a reset");

MODULE_PARM_DESC(flagaddr, "Address to write to boot flags to");

MODULE_PARM_DESC(nowayout, "Watchdog cannot be disabled once started");

MODULE_PARM_DESC(powercycle, "Cycle power if watchdog expires");