Commit 70c14ff0 authored by Dan Williams's avatar Dan Williams Committed by Russell King
Browse files

[ARM] 4495/1: iop: combined watchdog timer driver for iop3xx and iop13xx 



In order for this driver to be shared across the iop architectures the
iop3xx and iop13xx header files are modified to present a common interface
for the iop_wdt driver.

Details:
* iop13xx supports disabling the timer while iop3xx does not.  This requires
  a few 'compatibility' definitions in include/asm-arm/hardware/iop3xx.h to
  preclude adding #ifdef CONFIG_ARCH_IOP13XX blocks to the driver code.
* The heartbeat interval is derived from the internal bus clock rate, so this
  this patch also exports the tick rate to the iop_wdt driver.

Cc: Curt Bruns <curt.e.bruns@intel.com>
Cc: Peter Milne <peter.milne@d-tacq.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Acked-by: default avatarWim Van Sebroeck <wim@iguana.be>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 7dea1b20

arch/arm/plat-iop/time.c

+8 −0
Original line number Diff line number Diff line
@@ -78,6 +78,13 @@ static struct irqaction iop_timer_irq = { 
	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,

};



static unsigned long iop_tick_rate;

unsigned long get_iop_tick_rate(void)

{

	return iop_tick_rate;

}

EXPORT_SYMBOL(get_iop_tick_rate);



void __init iop_init_time(unsigned long tick_rate)

{

	u32 timer_ctl;
@@ -85,6 +92,7 @@ void __init iop_init_time(unsigned long tick_rate) 
	ticks_per_jiffy = (tick_rate + HZ/2) / HZ;

	ticks_per_usec = tick_rate / 1000000;

	next_jiffy_time = 0xffffffff;

	iop_tick_rate = tick_rate;



	timer_ctl = IOP_TMR_EN | IOP_TMR_PRIVILEGED |

			IOP_TMR_RELOAD | IOP_TMR_RATIO_1_1;

drivers/char/watchdog/Kconfig

+16 −0
Original line number Diff line number Diff line
@@ -187,6 +187,22 @@ config PNX4008_WATCHDOG 


	  Say N if you are unsure.



config IOP_WATCHDOG

	tristate "IOP Watchdog"

	depends on WATCHDOG && PLAT_IOP

	select WATCHDOG_NOWAYOUT if (ARCH_IOP32X || ARCH_IOP33X)

	help

	  Say Y here if to include support for the watchdog timer

	  in the Intel IOP3XX & IOP13XX I/O Processors.  This driver can

	  be built as a module by choosing M. The module will

	  be called iop_wdt.



	  Note: The IOP13XX watchdog does an Internal Bus Reset which will

	  affect both cores and the peripherals of the IOP.  The ATU-X

	  and/or ATUe configuration registers will remain intact, but if

	  operating as an Root Complex and/or Central Resource, the PCI-X

	  and/or PCIe busses will also be reset.  THIS IS A VERY BIG HAMMER.



# AVR32 Architecture



config AT32AP700X_WDT

drivers/char/watchdog/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o 
obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o

obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o

obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o

obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o



# AVR32 Architecture

obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o

drivers/char/watchdog/iop_wdt.c

0 → 100644
+262 −0
Original line number Diff line number Diff line 
/*

 * drivers/char/watchdog/iop_wdt.c

 *

 * WDT driver for Intel I/O Processors

 * Copyright (C) 2005, Intel Corporation.

 *

 * Based on ixp4xx driver, Copyright 2004 (c) MontaVista, Software, Inc.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope 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.

 *

 *	Curt E Bruns <curt.e.bruns@intel.com>

 *	Peter Milne <peter.milne@d-tacq.com>

 *	Dan Williams <dan.j.williams@intel.com>

 */



#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/fs.h>

#include <linux/init.h>

#include <linux/device.h>

#include <linux/miscdevice.h>

#include <linux/watchdog.h>

#include <linux/uaccess.h>

#include <asm/hardware.h>



static int nowayout = WATCHDOG_NOWAYOUT;

static unsigned long wdt_status;

static unsigned long boot_status;



#define WDT_IN_USE		0

#define WDT_OK_TO_CLOSE		1

#define WDT_ENABLED		2



static unsigned long iop_watchdog_timeout(void)

{

	return (0xffffffffUL / get_iop_tick_rate());

}



/**

 * wdt_supports_disable - determine if we are accessing a iop13xx watchdog

 * or iop3xx by whether it has a disable command

 */

static int wdt_supports_disable(void)

{

	int can_disable;



	if (IOP_WDTCR_EN_ARM != IOP_WDTCR_DIS_ARM)

		can_disable = 1;

	else

		can_disable = 0;



	return can_disable;

}



static void wdt_enable(void)

{

	/* Arm and enable the Timer to starting counting down from 0xFFFF.FFFF

	 * Takes approx. 10.7s to timeout

	 */

	write_wdtcr(IOP_WDTCR_EN_ARM);

	write_wdtcr(IOP_WDTCR_EN);

}



/* returns 0 if the timer was successfully disabled */

static int wdt_disable(void)

{

	/* Stop Counting */

	if (wdt_supports_disable()) {

		write_wdtcr(IOP_WDTCR_DIS_ARM);

		write_wdtcr(IOP_WDTCR_DIS);

		clear_bit(WDT_ENABLED, &wdt_status);

		printk(KERN_INFO "WATCHDOG: Disabled\n");

		return 0;

	} else

		return 1;

}



static int iop_wdt_open(struct inode *inode, struct file *file)

{

	if (test_and_set_bit(WDT_IN_USE, &wdt_status))

		return -EBUSY;



	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);



	wdt_enable();



	set_bit(WDT_ENABLED, &wdt_status);



	return nonseekable_open(inode, file);

}



static ssize_t

iop_wdt_write(struct file *file, const char *data, size_t len,

		  loff_t *ppos)

{

	if (len) {

		if (!nowayout) {

			size_t i;



			clear_bit(WDT_OK_TO_CLOSE, &wdt_status);



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

				char c;



				if (get_user(c, data + i))

					return -EFAULT;

				if (c == 'V')

					set_bit(WDT_OK_TO_CLOSE, &wdt_status);

			}

		}

		wdt_enable();

	}



	return len;

}



static struct watchdog_info ident = {

	.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,

	.identity = "iop watchdog",

};



static int

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

		  unsigned long arg)

{

	int options;

	int ret = -ENOTTY;



	switch (cmd) {

	case WDIOC_GETSUPPORT:

		if (copy_to_user

		    ((struct watchdog_info *)arg, &ident, sizeof ident))

			ret = -EFAULT;

		else

			ret = 0;

		break;



	case WDIOC_GETSTATUS:

		ret = put_user(0, (int *)arg);

		break;



	case WDIOC_GETBOOTSTATUS:

		ret = put_user(boot_status, (int *)arg);

		break;



	case WDIOC_GETTIMEOUT:

		ret = put_user(iop_watchdog_timeout(), (int *)arg);

		break;



	case WDIOC_KEEPALIVE:

		wdt_enable();

		ret = 0;

		break;



	case WDIOC_SETOPTIONS:

		if (get_user(options, (int *)arg))

			return -EFAULT;



		if (options & WDIOS_DISABLECARD) {

			if (!nowayout) {

				if (wdt_disable() == 0) {

					set_bit(WDT_OK_TO_CLOSE, &wdt_status);

					ret = 0;

				} else

					ret = -ENXIO;

			} else

				ret = 0;

		}



		if (options & WDIOS_ENABLECARD) {

			wdt_enable();

			ret = 0;

		}

		break;

	}



	return ret;

}



static int iop_wdt_release(struct inode *inode, struct file *file)

{

	int state = 1;

	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))

		if (test_bit(WDT_ENABLED, &wdt_status))

			state = wdt_disable();



	/* if the timer is not disbaled reload and notify that we are still

	 * going down

	 */

	if (state != 0) {

		wdt_enable();

		printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "

		       "reset in %lu seconds\n", iop_watchdog_timeout());

	}



	clear_bit(WDT_IN_USE, &wdt_status);

	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);



	return 0;

}



static const struct file_operations iop_wdt_fops = {

	.owner = THIS_MODULE,

	.llseek = no_llseek,

	.write = iop_wdt_write,

	.ioctl = iop_wdt_ioctl,

	.open = iop_wdt_open,

	.release = iop_wdt_release,

};



static struct miscdevice iop_wdt_miscdev = {

	.minor = WATCHDOG_MINOR,

	.name = "watchdog",

	.fops = &iop_wdt_fops,

};



static int __init iop_wdt_init(void)

{

	int ret;



	ret = misc_register(&iop_wdt_miscdev);

	if (ret == 0)

		printk("iop watchdog timer: timeout %lu sec\n",

		       iop_watchdog_timeout());



	/* check if the reset was caused by the watchdog timer */

	boot_status = (read_rcsr() & IOP_RCSR_WDT) ? WDIOF_CARDRESET : 0;



	/* Configure Watchdog Timeout to cause an Internal Bus (IB) Reset

	 * NOTE: An IB Reset will Reset both cores in the IOP342

	 */

	write_wdtsr(IOP13XX_WDTCR_IB_RESET);



	return ret;

}



static void __exit iop_wdt_exit(void)

{

	misc_deregister(&iop_wdt_miscdev);

}



module_init(iop_wdt_init);

module_exit(iop_wdt_exit);



module_param(nowayout, int, 0);

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



MODULE_AUTHOR("Curt E Bruns <curt.e.bruns@intel.com>");

MODULE_DESCRIPTION("iop watchdog timer driver");

MODULE_LICENSE("GPL");

MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

include/asm-arm/arch-iop13xx/iop13xx.h

+43 −0
Original line number Diff line number Diff line
@@ -19,6 +19,39 @@ static inline int iop13xx_cpu_id(void) 
	return id;

}



/* WDTCR CP6 R7 Page 9 */

static inline u32 read_wdtcr(void)

{

	u32 val;

	asm volatile("mrc p6, 0, %0, c7, c9, 0":"=r" (val));

	return val;

}

static inline void write_wdtcr(u32 val)

{

	asm volatile("mcr p6, 0, %0, c7, c9, 0"::"r" (val));

}



/* WDTSR CP6 R8 Page 9 */

static inline u32 read_wdtsr(void)

{

	u32 val;

	asm volatile("mrc p6, 0, %0, c8, c9, 0":"=r" (val));

	return val;

}

static inline void write_wdtsr(u32 val)

{

	asm volatile("mcr p6, 0, %0, c8, c9, 0"::"r" (val));

}



/* RCSR - Reset Cause Status Register  */

static inline u32 read_rcsr(void)

{

	u32 val;

	asm volatile("mrc p6, 0, %0, c0, c1, 0":"=r" (val));

	return val;

}



extern unsigned long get_iop_tick_rate(void);

#endif



/*
@@ -480,4 +513,14 @@ static inline int iop13xx_cpu_id(void) 
#define IOP13XX_PBI_LR1       		IOP13XX_PBI_OFFSET(0x14)



#define IOP13XX_PROCESSOR_FREQ		IOP13XX_REG_ADDR32(0x2180)



/* Watchdog timer definitions */

#define IOP_WDTCR_EN_ARM  	0x1e1e1e1e

#define IOP_WDTCR_EN      	0xe1e1e1e1

#define IOP_WDTCR_DIS_ARM 	0x1f1f1f1f

#define IOP_WDTCR_DIS     	0xf1f1f1f1

#define IOP_RCSR_WDT		(1 << 5) /* reset caused by watchdog timer */

#define IOP13XX_WDTSR_WRITE_EN	(1 << 31) /* used to speed up reset requests */

#define IOP13XX_WDTCR_IB_RESET	(1 << 0)



#endif /* _IOP13XX_HW_H_ */

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