Re: PowerPC4xx Watchdog

On Fri, Mar 04, 2005 at 12:21:13AM +0900, Takeharu KATO wrote:

Hi Kumar,

Thank you for your suggestion.
Kumar Gala wrote:

quoted

One thing the code needs is a general name cleanup.  Its just confusing 
to me for e500 to have 4xx references.

How about the use of booke instead of 4xx?

Yes, please. :)

I seem to use ``booke'' for common name for them like 
arch/ppc/kernel/head_booke.h in the kernel source.

Strictly speaking, PowerPC4xx series may not be called booke.
But I think that it is more preferable than current name.

440 is strictly Book E, 405 is a hybrid that pulled borrowed
from Green book and Book E.

-Matt

Matt and Kurmar:

I performed name-cleanup in the driver.

Moreover, I tested this driver with PowerPC405GPr(Sycamore)
in addition to PowerPC440GP(ebony)/MPC8555(MPC8555-CDS).

This driver consist of two patches as follows:

1) Architecture specific part(booke_wdt-arch.patch)
This is the architecture specific part of the driver.
It contains WDT exception handlers
and kernel command line processing
routines.

2) Device driver part(booke_wdt-drv.patch)
This is the core of this WDT
driver.

At first, I post the architecture specific part with this mail.

Please apply.

Regards,

Signed-off-by: Takeharu KATO <redacted>

--- linux-2.6.11/arch/ppc/kernel/head_44x.S	2005-03-04 17:12:42.944450424 +0900
+++ linux-2.6.11-booke-wdt/arch/ppc/kernel/head_44x.S	2005-03-04 13:21:31.000000000 +0900

@@ -444,8 +444,12 @@ interrupt_base:
 	EXCEPTION(0x1010, FixedIntervalTimer, UnknownException, EXC_XFER_EE)

 	/* Watchdog Timer Interrupt */
-	/* TODO: Add watchdog support */
+#if defined(CONFIG_BOOKE_WDT)
+	CRITICAL_EXCEPTION(0x1020, WatchdogTimer, booke_wdt_exception)
+#else
 	CRITICAL_EXCEPTION(0x1020, WatchdogTimer, UnknownException)
+#endif  /*  CONFIG_BOOKE_WDT  */
+	

 	/* Data TLB Error Interrupt */
 	START_EXCEPTION(DataTLBError)
--- linux-2.6.11/arch/ppc/kernel/head_4xx.S	2005-03-04 17:16:48.089182760 +0900
+++ linux-2.6.11-booke-wdt/arch/ppc/kernel/head_4xx.S	2005-03-04 13:21:31.000000000 +0900

@@ -469,27 +469,23 @@ label:

 /* 0x1000 - Programmable Interval Timer (PIT) Exception */
 	START_EXCEPTION(0x1000, Decrementer)
-	NORMAL_EXCEPTION_PROLOG
-	lis	r0,TSR_PIS@h
-	mtspr	SPRN_TSR,r0		/* Clear the PIT exception */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	EXC_XFER_LITE(0x1000, timer_interrupt)
-
+	b	DecrementerHandler
 #if 0
 /* NOTE:
- * FIT and WDT handlers are not implemented yet.
+ * FIT handler are not implemented yet.
  */

 /* 0x1010 - Fixed Interval Timer (FIT) Exception
 */
 	STND_EXCEPTION(0x1010,	FITException,		UnknownException)

-/* 0x1020 - Watchdog Timer (WDT) Exception
-*/
-
-	CRITICAL_EXCEPTION(0x1020, WDTException, UnknownException)
 #endif

+  /* 0x1020 - Watchdog Timer (WDT) Exception
+  */
+	START_EXCEPTION(0x1020, WDTException)
+	b	WatchDogHandler
+
 /* 0x1100 - Data TLB Miss Exception
  * As the name implies, translation is not in the MMU, so search the
  * page tables and fix it.  The only purpose of this function is to

@@ -771,6 +767,14 @@ label:
 		(MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
 		NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)

+
+DecrementerHandler:
+	NORMAL_EXCEPTION_PROLOG
+	lis	r0,TSR_PIS@h
+	mtspr	SPRN_TSR,r0		/* Clear the PIT exception */
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	EXC_XFER_LITE(0x1000, timer_interrupt)
+
 /*
  * The other Data TLB exceptions bail out to this point
  * if they can't resolve the lightweight TLB fault.

@@ -844,6 +848,19 @@ finish_tlb_load:
 	rfi			/* Should sync shadow TLBs */
 	b	.		/* prevent prefetch past rfi */

+/*
+ * WatchDog Exception
+ */
+WatchDogHandler:
+	CRITICAL_EXCEPTION_PROLOG;
+	addi	r3,r1,STACK_FRAME_OVERHEAD;
+#if defined(CONFIG_BOOKE_WDT)
+	EXC_XFER_TEMPLATE(booke_wdt_exception, 0x1022, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)),NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)
+
+#else
+	EXC_XFER_TEMPLATE(UnknownException, 0x1022, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)),NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)
+#endif  /*  CONFIG_BOOKE_WDT  */
+
 /* extern void giveup_fpu(struct task_struct *prev)
  *
  * The PowerPC 4xx family of processors do not have an FPU, so this just
--- linux-2.6.11/arch/ppc/kernel/head_e500.S	2005-03-04 17:15:36.641044528 +0900
+++ linux-2.6.11-booke-wdt/arch/ppc/kernel/head_e500.S	2005-03-04 13:21:31.000000000 +0900

@@ -494,8 +494,11 @@ interrupt_base:
 	EXCEPTION(0x3100, FixedIntervalTimer, UnknownException, EXC_XFER_EE)

 	/* Watchdog Timer Interrupt */
-	/* TODO: Add watchdog support */
+#if defined(CONFIG_BOOKE_WDT)
+	CRITICAL_EXCEPTION(0x3200, WatchdogTimer, booke_wdt_exception)
+#else
 	CRITICAL_EXCEPTION(0x3200, WatchdogTimer, UnknownException)
+#endif  /*  CONFIG_BOOKE_WDT  */

 	/* Data TLB Error Interrupt */
 	START_EXCEPTION(DataTLBError)
--- linux-2.6.11/arch/ppc/platforms/85xx/mpc8540_ads.c	2005-03-04 17:13:11.927044400 +0900
+++ linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/mpc8540_ads.c	2005-03-04 13:21:31.000000000 +0900

@@ -54,6 +54,7 @@

 #include <syslib/ppc85xx_setup.h>

+
 /* ************************************************************************
  *
  * Setup the architecture

@@ -187,6 +188,14 @@ platform_init(unsigned long r3, unsigned
 		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
 	}

+#ifdef CONFIG_BOOKE_WDT
+     {
+       extern void booke_wdt_setup_options(char *cmd_line);
+
+       booke_wdt_setup_options(cmd_line);
+     }
+#endif  /*  CONFIG_BOOKE_WDT  */
+
 	identify_ppc_sys_by_id(mfspr(SVR));

 	/* setup the PowerPC module struct */
--- linux-2.6.11/arch/ppc/platforms/85xx/mpc8560_ads.c	2005-03-04 17:17:54.566076736 +0900
+++ linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/mpc8560_ads.c	2005-03-04 13:21:31.000000000 +0900

@@ -197,6 +197,14 @@ platform_init(unsigned long r3, unsigned
 		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
 	}

+#ifdef CONFIG_BOOKE_WDT
+     {
+       extern void booke_wdt_setup_options(char *cmd_line);
+
+       booke_wdt_setup_options(cmd_line);
+     }
+#endif  /*  CONFIG_BOOKE_WDT  */
+
 	identify_ppc_sys_by_id(mfspr(SVR));

 	/* setup the PowerPC module struct */
--- linux-2.6.11/arch/ppc/platforms/85xx/mpc85xx_cds_common.c	2005-03-04 17:16:27.056380232 +0900
+++ linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/mpc85xx_cds_common.c	2005-03-04 13:21:31.000000000 +0900

@@ -437,6 +437,14 @@ platform_init(unsigned long r3, unsigned
                 strcpy(cmd_line, (char *) (r6 + KERNELBASE));
         }

+#ifdef CONFIG_BOOKE_WDT
+     {
+       extern void booke_wdt_setup_options(char *cmd_line);
+
+       booke_wdt_setup_options(cmd_line);
+     }
+#endif  /*  CONFIG_BOOKE_WDT  */
+
 	identify_ppc_sys_by_id(mfspr(SVR));

         /* setup the PowerPC module struct */
--- linux-2.6.11/arch/ppc/platforms/85xx/sbc8560.c	2005-03-04 17:17:22.985877656 +0900
+++ linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/sbc8560.c	2005-03-04 13:21:31.000000000 +0900

@@ -198,6 +198,14 @@ platform_init(unsigned long r3, unsigned
 		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
 	}

+#ifdef CONFIG_BOOKE_WDT
+     {
+       extern void booke_wdt_setup_options(char *cmd_line);
+
+       booke_wdt_setup_options(cmd_line);
+     }
+#endif  /*  CONFIG_BOOKE_WDT  */
+
 	identify_ppc_sys_by_id(mfspr(SVR));

 	/* setup the PowerPC module struct */
--- linux-2.6.11/arch/ppc/platforms/85xx/stx_gp3.c	2005-03-04 17:14:12.883777568 +0900
+++ linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/stx_gp3.c	2005-03-04 13:21:31.000000000 +0900

@@ -68,6 +68,7 @@ unsigned long isa_mem_base = 0;
 unsigned long pci_dram_offset = 0;
 #endif

+
 /* Internal interrupts are all Level Sensitive, and Positive Polarity */
 static u8 gp3_openpic_initsenses[] __initdata = {
 	(IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE),	/* Internal  0: L2 Cache */

@@ -357,6 +358,14 @@ platform_init(unsigned long r3, unsigned
 		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
 	}

+#ifdef CONFIG_BOOKE_WDT
+     {
+       extern void booke_wdt_setup_options(char *cmd_line);
+
+       booke_wdt_setup_options(cmd_line);
+     }
+#endif  /*  CONFIG_BOOKE_WDT  */
+
 	identify_ppc_sys_by_id(mfspr(SVR));

 	/* setup the PowerPC module struct */
--- linux-2.6.11/arch/ppc/syslib/ppc4xx_setup.c	2005-03-04 17:10:56.867576560 +0900
+++ linux-2.6.11-booke-wdt/arch/ppc/syslib/ppc4xx_setup.c	2005-03-04 13:21:31.000000000 +0900

@@ -48,10 +48,6 @@
 extern void abort(void);
 extern void ppc4xx_find_bridges(void);

-extern void ppc4xx_wdt_heartbeat(void);
-extern int wdt_enable;
-extern unsigned long wdt_period;
-
 /* Global Variables */
 bd_t __res;

@@ -257,22 +253,14 @@ ppc4xx_init(unsigned long r3, unsigned l
 		*(char *) (r7 + KERNELBASE) = 0;
 		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
 	}
-#if defined(CONFIG_PPC405_WDT)
-/* Look for wdt= option on command line */
-	if (strstr(cmd_line, "wdt=")) {
-		int valid_wdt = 0;
-		char *p, *q;
-		for (q = cmd_line; (p = strstr(q, "wdt=")) != 0;) {
-			q = p + 4;
-			if (p > cmd_line && p[-1] != ' ')
-				continue;
-			wdt_period = simple_strtoul(q, &q, 0);
-			valid_wdt = 1;
-			++q;
-		}
-		wdt_enable = valid_wdt;
-	}
-#endif
+
+#ifdef CONFIG_BOOKE_WDT
+     {
+       extern void booke_wdt_setup_options(char *cmd_line);
+
+       booke_wdt_setup_options(cmd_line);
+     }
+#endif  /*  CONFIG_BOOKE_WDT  */

 	/* Initialize machine-dependent vectors */

@@ -319,3 +307,5 @@ void platform_machine_check(struct pt_re
 #endif

 }
+
+

Matt and Kurmar:

I post the device driver part with this mail.

This is the last part of this driver.

Please apply.

Regards,

Signed-off-by: Takeharu KATO <redacted>

--- linux-2.6.11/drivers/char/watchdog/Kconfig	2005-03-04 17:14:57.687966296 +0900
+++ linux-2.6.11-booke-wdt/drivers/char/watchdog/Kconfig	2005-03-04 13:21:32.000000000 +0900

@@ -346,6 +346,13 @@ config 8xx_WDT
 	tristate "MPC8xx Watchdog Timer"
 	depends on WATCHDOG && 8xx

+config BOOKE_WDT
+    bool "Book E(PowerPC 4xx/e500) Watchdog Timer"
+    depends on WATCHDOG && ( 4xx || E500 )
+    ---help---
+      This is the driver for the watchdog timers on
+      PowerPC 4xx and PowerPC e500.
+
 # MIPS Architecture

 config INDYDOG
--- linux-2.6.11/drivers/char/watchdog/Makefile	2005-03-04 17:15:30.582965496 +0900
+++ linux-2.6.11-booke-wdt/drivers/char/watchdog/Makefile	2005-03-04 13:21:32.000000000 +0900

@@ -39,3 +39,4 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.
 obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
 obj-$(CONFIG_IXP2000_WATCHDOG) += ixp2000_wdt.o
 obj-$(CONFIG_8xx_WDT) += mpc8xx_wdt.o
+obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o
--- linux-2.6.11/drivers/char/watchdog/booke_wdt.c	1970-01-01 09:00:00.000000000 +0900
+++ linux-2.6.11-booke-wdt/drivers/char/watchdog/booke_wdt.c	2005-03-04 16:38:58.000000000 +0900

@@ -0,0 +1,664 @@
+/*
+ *    Copyright (c) 2005 Fujitsu Limited
+ *
+ *    Module name: booke_wdt.c
+ *    Author:      Takeharu KATO<kato.takeharu@jp.fujitsu.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.
+ *
+ *    Neither Takeharu KATO nor Fujitsu Ltd. admit liability nor provide
+ *    warranty for any of this software.
+ *
+ *    Description:
+ *     Watchdog driver for PowerPC Book E (PowerPC 4xx series processors and
+ *     PowerPC e500 series processors).
+ *     Derived from drivers/char/watchdog/wdt.c by Alan cox
+ *              and  drivers/char/watchdog/ppc405_wdt.c by Armin Kuster.
+ *     PPC4xx WDT operation is driverd from Appendix of
+ *     PowerPC Embedded Processors Application Note
+ *      ``PowerPC 40x Watch Dog Timer'' published from IBM.
+ *     This driver is written according to ``PowerPC e500 Core Complex
+ *     Reference Manual'' for e500 part.
+ */
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/capability.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <asm/reg.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include "booke_wdt.h"
+
+/* micro seconds per one milli-second(used to calculatewatchdog
+ * counter to be set). */
+#define US_PER_MS 1000
+/*  Calculate watchdog count   */
+#define calculate_wdt_count(t) ((((unsigned long)(t))*HZ)/1000)
+
+int wdt_enable=0;             /* WDT start on boot  */
+int wdt_period=WDT_TIMO;       /* Time out in ms */
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+/*
+ * Global variables
+ */
+static int wdt_count = 0;            /* WDT intrrupt counter to be reloaded */
+static volatile int wdt_heartbeat_count = 0;  /* WDT intrrupt counter(compatible mode)*/
+static unsigned long driver_state; /* Driver status (see: booke_wdt.h) */
+/*
+ *  Identifier for this watchdog
+ */
+static struct watchdog_info ident = {
+  .options=WDIOF_SETTIMEOUT|WDIOF_KEEPALIVEPING|WDIOF_MAGICCLOSE,
+  .firmware_version =    0, /*  This is filled with PVR in initialization. */
+  .identity =        "Book E(PPC 4xx/e500) WDT",
+};
+
+/*
+ *  PowerPC Linux common exception handler
+ */
+extern void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr);
+/*  Panic notifier  */
+extern struct notifier_block *panic_notifier_list;
+/*
+ *  External linkage functions
+ */
+void booke_wdt_heartbeat(void);
+void booke_wdt_setup_options(char *cmd_line);
+void booke_wdt_exception(struct pt_regs *regs);
+/*
+ * Internal linkage functions
+ */
+static __inline__ void __booke_wdt_setup_val(int period,int reset);
+static __inline__ void __booke_wdt_enable(void);
+static __inline__ void __booke_wdt_disable(void);
+static __inline__ int  __booke_wdt_is_enabled(void);
+static __inline__ void __booke_wdt_clear_int_stat(void);
+static __inline__ void __booke_wdt_set_timeout(int t);
+static __inline__ void booke_wdt_init_device(void);
+static __inline__ int  booke_wdt_is_enabled(void);
+static __inline__ int  booke_wdt_start(void);
+static __inline__ int  booke_wdt_stop(void);
+static __inline__ int  booke_wdt_ping(void);
+static __inline__ int  booke_wdt_set_timeout(int t);
+static __inline__ int  booke_wdt_get_status(int *status);
+static ssize_t booke_wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos);
+static int booke_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,unsigned long arg);
+static int booke_wdt_open(struct inode *inode, struct file *file);
+static int booke_wdt_release(struct inode *inode, struct file *file);
+static int booke_wdt_notify_sys(struct notifier_block *this, unsigned long code,void *unused);
+static int __init booke_wdt_init(void);
+static void __exit booke_wdt_exit(void);
+
+/*
+ *    Watchdog operations on PPC4xx/e500 MPU
+ */
+
+/**
+ *      __booke_wdt_setup_val
+ *      Enable Watchdog, sets up passed in values for TCR[WP],
+ *      TCR[WRC]
+ *
+ *    @period:    Input Watchdog Period - TCR[WP]
+ *                      0 = 217 clocks
+ *                      1 = 221 clocks
+ *                      2 = 225 clocks
+ *                      3 = 229 clocks
+ *      @reset:         Watchdog reset control - TCR[WRC]
+ *                      0 = No reset
+ *                      1 = PPC Core reset only
+ *                      2 = PPC Chip reset
+ *                      3 = System reset
+ *     Note: The meaning of period number is differ PPC440GP from PPC440GX.
+ */
+#if defined(CONFIG_4xx)
+static __inline__ void
+__booke_wdt_setup_val(int period,int reset)
+{
+  unsigned long val;
+
+  /*  Set up TCR  */
+  val=((period)<<WDT_TCR_WP_SHIFT|(reset)<<WDT_TCR_WRC_SHIFT)|mfspr(SPRN_TCR);
+  /*  Disable WDT  */
+  val &= ~(WDT_TCR_WDT_ENABLE);
+
+  mtspr(SPRN_TCR,val);
+}
+#else
+/*  e500  */
+static __inline__ void
+__booke_wdt_setup_val(int period,int reset)
+{
+  unsigned long val;
+  /*  Set up TCR  */
+
+  val=(((period)&(WDT_TCR_WP_BITMSK)) << WDT_TCR_WP_SHIFT|
+       ( ( (period) >> 2 )&(WDT_TCR_WPEXT_BITMSK)) << WDT_TCR_WPEXT_SHIFT|
+       (reset)<<WDT_TCR_WRC_SHIFT)|mfspr(SPRN_TCR);
+  /*  Disable WDT  */
+  val &= ~(WDT_TCR_WDT_ENABLE);
+
+  mtspr(SPRN_TCR,val);
+}
+#endif  /*  CONFIG_E500 */
+/**
+ *      __booke_wdt_enable
+ *      Enable Watchdog
+ */
+static __inline__ void
+__booke_wdt_enable(void)
+{
+  mtspr(SPRN_TCR,(mfspr(SPRN_TCR)|WDT_TCR_WDT_ENABLE));
+}
+/**
+ *      __booke_wdt_disable
+ *      Disable Watchdog
+ */
+static __inline__ void
+__booke_wdt_disable(void)
+{
+  mtspr(SPRN_TCR,(mfspr(SPRN_TCR)&(~(WDT_TCR_WDT_ENABLE))));
+}
+/**
+ *      __booke_wdt_is_enabled
+ *      Check whether Watchdog is enabled.
+ */
+static __inline__ int
+__booke_wdt_is_enabled(void)
+{
+  return (mfspr(SPRN_TCR) & WDT_TCR_WDT_ENABLE);
+}
+/**
+ *      __booke_wdt_clear_init_stat
+ *      Clear interrupt status of watchdog to ping it.
+ */
+static __inline__ void
+__booke_wdt_clear_int_stat(void)
+{
+  mtspr(SPRN_TSR, (TSR_ENW|TSR_WIS));
+}
+/**
+ *    __booke_wdt_set_timeout:
+ *    @t:    the new time out value that needs to be set.
+ *
+ *    Set a new time out value for the watchdog device.
+ *
+ */
+static __inline__ void
+__booke_wdt_set_timeout(int t)
+{
+  wdt_count=calculate_wdt_count(t);
+  return;
+}
+
+/*
+ * Driver specific functions
+ */
+
+/**
+ *   booke_wdt_setup_options
+ *   @cmd_line : a pointer to kernel command line.
+ *
+ */
+void
+booke_wdt_setup_options(char *cmd_line)
+{
+/*
+ * Look for wdt= option on command line
+ */
+  if (strstr(cmd_line, "wdt=")) {
+    int valid_wdt = 0;
+    char *p, *q;
+
+    for (q = cmd_line; (p = strstr(q, "wdt=")) != 0;) {
+      q = p + 4;
+      if (p > cmd_line && p[-1] != ' ')
+    continue;
+      wdt_period = simple_strtoul(q, &q, 0);
+      valid_wdt = 1;
+      ++q;
+    }
+    wdt_enable = valid_wdt;
+  }
+  return;
+}
+/**
+ *    booke_wdt_heartbeat:
+ *      Ping routine called from kernel.
+ */
+void
+booke_wdt_heartbeat(void)
+{
+  /* Disable watchdog */
+  __booke_wdt_disable();
+
+  /* Write a watchdog value */
+  __booke_wdt_clear_int_stat();
+
+  if (!wdt_enable)
+    goto out;
+
+  if  (wdt_heartbeat_count > 0)
+    wdt_heartbeat_count--;
+  else
+    panic(booke_mkmsg("Initiating system reboot.\n"));
+
+  /* Enable watchdog */
+  __booke_wdt_enable();
+ out:
+  /*  Reset count  */
+  ppc_md.heartbeat_count = 0;
+}
+/**
+ *    booke_wdt_exception:
+ *      WatchDog Exception handler for PPC4xx/e500.
+ *      @regs : A registers information.
+ */
+void
+booke_wdt_exception(struct pt_regs *regs)
+{
+  wdt_enable=0;
+  __booke_wdt_disable();
+  printk("WDT Exception at PC: %lx, MSR: %lx, vector=%lx    %s\n",
+	 regs->nip, regs->msr, regs->trap, print_tainted());
+  panic(booke_mkmsg("Initiating system reboot.\n"));
+}
+/*
+ *    Driver Logic functions
+ */
+static __inline__ int
+booke_wdt_is_enabled(void)
+{
+  return  __booke_wdt_is_enabled();
+}
+/**
+ *    booke_wdt_start:
+ *
+ *    Start the watchdog driver.
+ */
+static __inline__ int
+booke_wdt_start(void)
+{
+  __booke_wdt_enable();
+  return 0;
+}
+
+/**
+ *    booke_wdt_stop:
+ *
+ *    Stop the watchdog driver.
+ */
+static __inline__ int
+booke_wdt_stop (void)
+{
+  __booke_wdt_disable();
+  return 0;
+}
+/**
+ *    booke_wdt_ping:
+ *
+ *    Reload counter one with the watchdog heartbeat. We don't bother reloading
+ *    the cascade counter.
+ */
+static __inline__ int
+booke_wdt_ping(void)
+{
+  /* Disable watchdog */
+  __booke_wdt_disable();
+  /* Write a watchdog value */
+  __booke_wdt_clear_int_stat();
+  /*  Reset count  */
+  wdt_heartbeat_count=wdt_count;
+  /* Enable watchdog */
+  __booke_wdt_enable();
+
+  return 0;
+}
+/**
+ *    booke_wdt_set_timeout:
+ *    @t:        the new timeout value that needs to be set.
+ *
+ *    Set a new time out value for the watchdog device.
+ *      If the heartbeat value is incorrect we keep the old value
+ *      and return -EINVAL. If successfull we return 0.
+ */
+static __inline__ int
+booke_wdt_set_timeout(int t)
+{
+  if ((t < WDT_HEARTBEAT_MIN) || (t > WDT_HEARTBEAT_MAX))
+    return -EINVAL;
+
+  wdt_period = t;
+  __booke_wdt_set_timeout(t);
+  wdt_heartbeat_count=wdt_count;
+  booke_wdt_dbg("The WDT counter set %d.\n",wdt_count);
+
+  return 0;
+}
+
+/**
+ *    booke_wdt_get_status:
+ *    @status: the new status.
+ *
+ *    Return the enable/disable card status.
+ */
+static __inline__ int
+booke_wdt_get_status(int *status)
+{
+  if (wdt_enable)
+      *status = WDIOS_ENABLECARD;
+  else
+      *status = WDIOS_DISABLECARD;
+
+  return 0;
+}
+/*
+ *    Kernel Interfaces
+ */
+/**
+ *    booke_wdt_init_device:
+ *
+ *      Initilize PowerPC 4xx/e500 family Watch Dog facility.
+ */
+static void
+booke_wdt_init_device(void)
+{
+        /* Hardware WDT provided by the processor.
+     * So, we set firmware version as processor version number.
+     */
+    ident.firmware_version=mfspr(PVR);
+    __booke_wdt_setup_val(WDT_WP,WDT_RESET_NONE);
+}
+/**
+ *    booke_wdt_write:
+ *    @file: file handle to the watchdog
+ *    @buf: buffer to write (unused as data does not matter here
+ *    @count: count of bytes
+ *    @ppos: pointer to the position to write. No seeks allowed
+ *
+ *    A write to a watchdog device is defined as a keepalive signal. Any
+ *    write of data will do, as we we don't define content meaning expept
+ *      'V' character. It is performed as a sign to set stop-on-close mode.
+ */
+
+static ssize_t
+booke_wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
+{
+  size_t i;
+
+    if (!nowayout) {
+      /* In case it was set long ago */
+      clear_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state);
+
+      for (i = 0; i < count; i++) {
+    char c;
+
+    if (get_user(c, buf + i))
+      return -EFAULT;
+
+    if (c == 'V') {
+      set_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state);
+    }
+      }
+    }
+    booke_wdt_ping();
+
+  return count;
+}
+
+/**
+ *    booke_wdt_ioctl:
+ *    @inode: inode of the device
+ *    @file: file handle to the device
+ *    @cmd: watchdog command
+ *    @arg: argument pointer
+ *
+ */
+static int
+booke_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+    unsigned long arg)
+{
+    int new_timeout;
+    int status;
+
+    if (!capable(CAP_SYS_ADMIN))
+        return -EPERM;  /*  It may be too strict manner.  */
+    switch(cmd)
+    {
+    default:
+        return -ENOIOCTLCMD;
+    case WDIOC_GETSUPPORT:
+        if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(struct watchdog_info)))
+            return -EFAULT;
+        else
+            break;
+    case WDIOC_GETSTATUS:
+        booke_wdt_get_status(&status);
+        return put_user(status,(int *)arg);
+    case WDIOC_KEEPALIVE:
+        booke_wdt_ping();
+        break;
+    case WDIOC_SETTIMEOUT:
+        if (get_user(new_timeout, (int *)arg))
+            return -EFAULT;
+        if (booke_wdt_set_timeout(new_timeout))
+            return -EINVAL;
+        booke_wdt_ping();
+        break;
+    case WDIOC_GETTIMEOUT:
+        return put_user(wdt_period, (int *)arg);
+    case WDIOC_SETOPTIONS:
+        if (get_user(status, (int *)arg))
+            return -EFAULT;
+        /*  Return -EINVAL when the driver can not figure out
+         *  what it should do. Unknown cases are just ignored.
+         */
+        if ( (status & (WDIOS_DISABLECARD|WDIOS_ENABLECARD))
+             == (WDIOS_DISABLECARD|WDIOS_ENABLECARD) )
+            return -EINVAL;
+        if (status & WDIOS_DISABLECARD) {
+            wdt_enable = 0;
+            booke_wdt_stop();
+            booke_wdt_info("Watchdog timer is disabled\n");
+        }
+        if (status & WDIOS_ENABLECARD) {
+            wdt_enable = 1;
+            booke_wdt_start();
+            booke_wdt_info("Watchdog timer is enabled\n");
+        }
+        break;
+    }
+    return 0;
+}
+/**
+ *    booke_wdt_open:
+ *    @inode: inode of device
+ *    @file: file handle to device
+ *
+ *    The watchdog device has been opened. The watchdog device is single
+ *    open and start the WDT timer.
+ */
+static int
+booke_wdt_open(struct inode *inode, struct file *file)
+{
+    if (!capable(CAP_SYS_ADMIN))
+        return -EPERM;
+
+    if (test_and_set_bit(WDT_STATE_OPEN, &driver_state))
+        return -EBUSY;
+    /*
+     * Activate
+     */
+    booke_wdt_start();
+    wdt_enable=1;
+
+    if (nowayout)
+      set_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state);
+
+    return 0;
+}
+
+/**
+ *    booke_wdt_release:
+ *    @inode: inode to board
+ *    @file: file handle to board
+ *
+ */
+static int
+booke_wdt_release(struct inode *inode, struct file *file)
+{
+  if (test_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state)) {
+      booke_wdt_note("WDT device is stopped.\n");
+    booke_wdt_stop();
+    wdt_enable=0;
+  } else {
+    if ( (booke_wdt_is_enabled()) && (!nowayout) ) {
+      booke_wdt_note("WDT device may be closed unexpectedly.  WDT will not stop!\n");
+      booke_wdt_ping();
+    }
+  }
+  clear_bit(WDT_STATE_OPEN, &driver_state);
+
+  return 0;
+}
+/**
+ *    notify_sys:
+ *    @this: our notifier block
+ *    @code: the event being reported
+ *    @unused: unused
+ *    Note: This function assume that the panic notifier is called with CODE=0
+ *          (see panic function in kernel/panic.c).
+ */
+static int
+booke_wdt_notify_sys(struct notifier_block *this, unsigned long code,
+    void *unused)
+{
+
+    if (code != SYS_POWER_OFF)   /* Turn the card off */
+      booke_wdt_stop();
+
+    return NOTIFY_DONE;
+}
+
+static struct file_operations booke_wdt_fops = {
+    .owner        = THIS_MODULE,
+    .llseek        = no_llseek,
+    .write        = booke_wdt_write,
+    .ioctl        = booke_wdt_ioctl,
+    .open        = booke_wdt_open,
+    .release    = booke_wdt_release,
+};
+
+static struct miscdevice booke_wdt_miscdev = {
+    .minor    = WATCHDOG_MINOR,
+    .name    = "watchdog",
+    .fops    = &booke_wdt_fops,
+};
+
+/*
+ *    The WDT card needs to know about shutdowns in order to
+ *    turn WDT off.
+ */
+
+static struct notifier_block booke_wdt_notifier = {
+    .notifier_call = booke_wdt_notify_sys,
+};
+
+/**
+ *    cleanup_module:
+ *
+ *    If your watchdog is set to continue ticking on close and you unload
+ *    it, well it keeps ticking.  You just have to load a new
+ *    module in 60 seconds or reboot.
+ *      This behavior(more over the comments as above) is borrowed from
+ *      Alan cox's driver.
+ */
+
+static void __exit
+booke_wdt_exit(void)
+{
+    misc_deregister(&booke_wdt_miscdev);
+    unregister_reboot_notifier(&booke_wdt_notifier);
+    notifier_chain_unregister(&panic_notifier_list,&booke_wdt_notifier);
+}
+
+/**
+ *     booke_wdt_init:
+ *
+ *    Set up the WDT relevant timer facility.
+ */
+
+static int __init
+booke_wdt_init(void)
+{
+    int ret;
+    unsigned long flags;
+
+    ret = register_reboot_notifier(&booke_wdt_notifier);
+    if(ret) {
+      booke_wdt_err("Cannot register reboot notifier (err=%d)\n", ret);
+      return ret;
+    }
+
+    /* Register panic notifier  */
+    ret = notifier_chain_register(&panic_notifier_list,&booke_wdt_notifier);
+    if(ret) {
+      booke_wdt_err("Cannot register panic notifier (err=%d)\n", ret);
+      unregister_reboot_notifier(&booke_wdt_notifier);
+      return ret;
+    }
+
+    ret = 0;
+    booke_wdt_init_device();
+    /* Check that the heartbeat value is within it's range ; if not reset to the default */
+    if (booke_wdt_set_timeout(wdt_period)) {
+      if (wdt_period)
+        booke_wdt_info("The heartbeat value must be %d < wdt_period < %d, using %d\n",WDT_HEARTBEAT_MIN,WDT_HEARTBEAT_MAX,WDT_TIMO);
+      booke_wdt_set_timeout(WDT_TIMO);
+    }
+
+    local_irq_save(flags); /* Prevent timer interrupt */
+    ppc_md.heartbeat_count = 0;
+    ppc_md.heartbeat=booke_wdt_heartbeat;
+    local_irq_restore(flags);
+
+    booke_wdt_info("Book E(PPC 4xx/e500) Watchdog Driver. period=%d ms (nowayout=%d)\n",wdt_period, nowayout);
+
+    ret = misc_register(&booke_wdt_miscdev);
+    if (ret) {
+      booke_wdt_err("Cannot register miscdev on minor=%d (err=%d)\n",
+            WATCHDOG_MINOR, ret);
+        goto outmisc;
+    }
+
+    if (wdt_enable) {
+      booke_wdt_info("WDT start on boot.\n");
+      booke_wdt_start();
+    }
+out:
+    return ret;
+outmisc:
+    unregister_reboot_notifier(&booke_wdt_notifier);
+    local_irq_save(flags);
+    ppc_md.heartbeat=NULL;
+    ppc_md.heartbeat_count = 0;
+    local_irq_restore(flags);
+    goto out;
+}
+
+device_initcall(booke_wdt_init);
--- linux-2.6.11/drivers/char/watchdog/booke_wdt.h	1970-01-01 09:00:00.000000000 +0900
+++ linux-2.6.11-booke-wdt/drivers/char/watchdog/booke_wdt.h	2005-03-04 16:38:58.000000000 +0900

@@ -0,0 +1,125 @@
+/*
+ *
+ *    Copyright (c) 2004 Fujitsu Limited
+ *
+ *    Module name: booke_wdt.h
+ *    Author:      Takeharu KATO<kato.takeharu@jp.fujitsu.com>
+ *    Description:
+ *      Header file for PowerPC Book E(PPC 4xx/e500) watchdog driver.
+ *
+ *    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.
+ *
+ *    Neither Takeharu KATO nor Fujitsu Ltd. admit liability nor provide
+ *    warranty for any of this software.
+ *
+ */
+#ifndef _DRIVERS_CHAR_WATCHDOG_BOOKE_WDT_H
+#define _DRIVERS_CHAR_WATCHDOG_BOOKE_WDT_H
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/watchdog.h>
+
+/*
+ *  Driver state flags(bit position)
+ */
+#define WDT_STATE_OPEN                  0   /* driver is opend  */
+#define WDT_STATE_STOP_ON_CLOSE         1   /* Stop with close is expected */
+/*
+ * Configurations
+ */
+#define WDT_TIMO           60000    /* Default timeout = 60000 ms(1min) */
+#define WDT_HEARTBEAT_MIN  100          /* Minimum timeout = 100 ms */
+#define WDT_HEARTBEAT_MAX  600000       /* Maximum timeout = 600000ms(1hour) */
+#ifdef __KERNEL__
+//#define BOOKE_WDT_DEBUG                     /*  Debug switch */
+/*
+ *  Reset type
+ */
+#define WDT_RESET_NONE     0
+#define WDT_RESET_CORE     1
+#define WDT_RESET_CHIP     2
+#define WDT_RESET_SYS      3
+/*
+ *   Bit positions in  TCR register on PPC4xx/e500 series.
+ */
+#define WDT_TCR_WP_BIT     1   /*  WP  bit in TCR (bit[0..1])   */
+#define WDT_TCR_WRC_BIT    3   /*  WRC bit in TCR (bit[2..3])   */
+#define WDT_TCR_WIE_BIT    4   /*  WIE bit in TCR (bit[4])      */
+/*
+ *  TCR[WP] relevant definitions
+ */
+#define WDT_TCR_WP_SHIFT       (31 - WDT_TCR_WP_BIT)
+#define WDT_TCR_WRC_SHIFT      (31 - WDT_TCR_WRC_BIT)
+#define WDT_TCR_WIE_SHIFT      (31 - WDT_TCR_WIE_BIT)
+#define WDT_TCR_WDT_ENABLE     (1<<WDT_TCR_WIE_SHIFT)
+/*  MASK value to obatain TCR[WP]  */
+#define WDT_TCR_WP_MASK        (3<<(WDT_TCR_WP_SHIFT))
+
+/*  Watchdog timer periods can be set on PPC 4xx cpus. */
+#if defined(CONFIG_4xx)
+/*
+ *  For PowerPC 4xx
+ */
+#define WDT_WP0               0
+#define WDT_WP1               1
+#define WDT_WP2               2
+#define WDT_WP3               3
+#else
+#if defined(CONFIG_E500)
+/*
+ *  For e500 CPU
+ *  Actually, e500 can arbitrary periods can be set,
+ *  But this driver uses fix period value as same as PPC440
+ *  on purpose for simplicity.
+ *  Following values split into WP and WP_EXT parts in booke_wdt.c.
+ */
+#define WDT_WP0               21
+#define WDT_WP1               25
+#define WDT_WP2               29
+#define WDT_WP3               33
+#define WDT_TCR_WP_BITMSK     0x3  /*  2bit length  */
+#define WDT_TCR_WPEXT_BITMSK  0xf  /*  4bit length  */
+#define WDT_TCR_WPEXT_SHIFT  17
+#else
+#error "Book E WDT detects invalid configuration(Unknown CPU)"
+#endif  /*  CONFIG_E500  */
+#endif  /*  CONFIG_4xx   */
+/*
+ *  WP relevant values used in our driver.
+ *  Note:WDT period must be more than HZ(Timer ticks)
+ */
+#define WDT_WP                 WDT_WP3
+
+/*
+ *  IOCTL commands for comaptiblity for old driver
+ */
+#define WDIOC_GETPERIOD         WDIOC_GETTIMEOUT
+#define WDIOC_SETPERIOD         WDIOC_SETTIMEOUT
+
+/*
+ *  output messages
+ */
+#define __BOOKE_WDT_MSG "BookE-WDT : "
+#define booke_mkmsg(str) __BOOKE_WDT_MSG str
+#define booke_wdt_info(fmt,arg...) \
+    printk(KERN_INFO __BOOKE_WDT_MSG fmt,##arg)
+#define booke_wdt_note(fmt,arg...) \
+    printk(KERN_NOTICE __BOOKE_WDT_MSG fmt,##arg)
+#define booke_wdt_err(fmt,arg...) \
+    printk(KERN_ALERT __BOOKE_WDT_MSG fmt,##arg)
+#define booke_wdt_crit(fmt,arg...) \
+    printk(KERN_ALERT __BOOKE_WDT_MSG fmt,##arg)
+#if defined(BOOKE_WDT_DEBUG)
+#define booke_wdt_dbg(fmt,arg...) \
+    printk(KERN_ALERT __BOOKE_WDT_MSG fmt,##arg)
+#else
+#define booke_wdt_dbg(fmt,arg...) \
+        do{}while(0)
+#endif  /*  WDT_DEBUG  */
+
+#endif  /* __KERNEL__  */
+#endif  /*  _DRIVERS_CHAR_WATCHDOG_BOOKE_WDT_H  */

Out of interest how did you test this?  If I find some time I will test =20=

it on an e500 system, just havent given much thought on how to test the =20=

watchdog though.

- kumar

On Mar 4, 2005, at 3:38 AM, Takeharu KATO wrote:

2005-03-04 =20

13:21:31.000000000 +0900
 @@ -444,8 +444,12 @@ interrupt_base:
=A0 =A0=A0=A0=A0=A0 EXCEPTION(0x1010, FixedIntervalTimer, =

UnknownException, =20

EXC_XFER_EE)

=A0 =A0=A0=A0=A0=A0 /* Watchdog Timer Interrupt */
 -=A0=A0=A0=A0=A0=A0 /* TODO: Add watchdog support */
 +#if defined(CONFIG_BOOKE_WDT)
+=A0=A0=A0=A0=A0=A0 CRITICAL_EXCEPTION(0x1020, WatchdogTimer, =

booke_wdt_exception)

+#else
 =A0 =A0=A0=A0=A0=A0 CRITICAL_EXCEPTION(0x1020, WatchdogTimer, =

UnknownException)

2005-03-04 =20

13:21:31.000000000 +0900
 @@ -469,27 +469,23 @@ label:

=A0 /* 0x1000 - Programmable Interval Timer (PIT) Exception */
 =A0 =A0=A0=A0=A0=A0 START_EXCEPTION(0x1000, Decrementer)
 -=A0=A0=A0=A0=A0=A0 NORMAL_EXCEPTION_PROLOG
-=A0=A0=A0=A0=A0=A0 lis=A0=A0=A0=A0 r0,TSR_PIS@h
-=A0=A0=A0=A0=A0=A0 mtspr=A0=A0 SPRN_TSR,r0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=

=A0 /* Clear the PIT exception */

 -=A0=A0=A0=A0=A0=A0 addi=A0=A0=A0 r3,r1,STACK_FRAME_OVERHEAD
-=A0=A0=A0=A0=A0=A0 EXC_XFER_LITE(0x1000, timer_interrupt)
-
 +=A0=A0=A0=A0=A0=A0 b=A0=A0=A0=A0=A0=A0 DecrementerHandler
=A0 #if 0
 =A0 /* NOTE:
 - * FIT and WDT handlers are not implemented yet.
 + * FIT handler are not implemented yet.
 =A0=A0 */

=A0 /* 0x1010 - Fixed Interval Timer (FIT) Exception
 =A0 */
 =A0 =A0=A0=A0=A0=A0 STND_EXCEPTION(0x1010,=A0 FITException,=A0=A0 =

=A0=A0=A0=A0=A0=A0=A0 =20

UnknownException)

-/* 0x1020 - Watchdog Timer (WDT) Exception
 -*/
 -
 -=A0=A0=A0=A0=A0=A0 CRITICAL_EXCEPTION(0x1020, WDTException, =

UnknownException)

=A0 #endif

+=A0 /* 0x1020 - Watchdog Timer (WDT) Exception
 +=A0 */
 +=A0=A0=A0=A0=A0=A0 START_EXCEPTION(0x1020, WDTException)
+=A0=A0=A0=A0=A0=A0 b=A0=A0=A0=A0=A0=A0 WatchDogHandler
+
 =A0 /* 0x1100 - Data TLB Miss Exception
 =A0=A0 * As the name implies, translation is not in the MMU, so =

search the

 =A0=A0 * page tables and fix it.=A0 The only purpose of this function =

is to

 @@ -771,6 +767,14 @@ label:
 =A0 =A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 (MSR_KERNEL & =

~(MSR_ME|MSR_DE|MSR_CE)), \

 =A0 =A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 NOCOPY, =

crit_transfer_to_handler, ret_from_crit_exc)

=A0 /* Clear the PIT exception */

 +=A0=A0=A0=A0=A0=A0 addi=A0=A0=A0 r3,r1,STACK_FRAME_OVERHEAD
+=A0=A0=A0=A0=A0=A0 EXC_XFER_LITE(0x1000, timer_interrupt)
+
 =A0 /*
 =A0=A0 * The other Data TLB exceptions bail out to this point
 =A0=A0 * if they can't resolve the lightweight TLB fault.
 @@ -844,6 +848,19 @@ finish_tlb_load:
=A0 =A0=A0=A0=A0=A0 rfi=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=

=A0=A0 /* Should sync shadow TLBs */

 =A0 =A0=A0=A0=A0=A0 b=A0=A0=A0=A0=A0=A0 .=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=

=A0=A0=A0 /* prevent prefetch past rfi */

(MSR_KERNEL & =20

~(MSR_ME|MSR_DE|MSR_CE)),NOCOPY,
 crit_transfer_to_handler, ret_from_crit_exc)
+
 +#else
 +=A0=A0=A0=A0=A0=A0 EXC_XFER_TEMPLATE(UnknownException, 0x1022, =

(MSR_KERNEL & =20

~(MSR_ME|MSR_DE|MSR_CE)),NOCOPY,
 crit_transfer_to_handler, ret_from_crit_exc)
+#endif=A0 /*=A0 CONFIG_BOOKE_WDT=A0 */
 +
 =A0 /* extern void giveup_fpu(struct task_struct *prev)
 =A0=A0 *
 =A0=A0 * The PowerPC 4xx family of processors do not have an FPU, so =

this =20

just
 --- linux-2.6.11/arch/ppc/kernel/head_e500.S=A0=A0=A0 2005-03-04 =20
17:15:36.641044528 +0900
 +++ linux-2.6.11-booke-wdt/arch/ppc/kernel/head_e500.S=A0 2005-03-04 =20=

13:21:31.000000000 +0900
 @@ -494,8 +494,11 @@ interrupt_base:
=A0 =A0=A0=A0=A0=A0 EXCEPTION(0x3100, FixedIntervalTimer, =

UnknownException, =20

EXC_XFER_EE)

=A0 =A0=A0=A0=A0=A0 /* Watchdog Timer Interrupt */
 -=A0=A0=A0=A0=A0=A0 /* TODO: Add watchdog support */
 +#if defined(CONFIG_BOOKE_WDT)
+=A0=A0=A0=A0=A0=A0 CRITICAL_EXCEPTION(0x3200, WatchdogTimer, =

booke_wdt_exception)

+#else
 =A0 =A0=A0=A0=A0=A0 CRITICAL_EXCEPTION(0x3200, WatchdogTimer, =

UnknownException)

17:13:11.927044400 +0900
 +++ =20
linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/mpc8540_ads.c=A0=A0=A0=A0=

=A0=A0=A0 =20

2005-03-04 13:21:31.000000000 +0900
 @@ -54,6 +54,7 @@

=A0 #include <syslib/ppc85xx_setup.h>

+
 =A0 /* =20
=

***********************************************************************=20=

*
=A0=A0 *
 =A0=A0 * Setup the architecture
 @@ -187,6 +188,14 @@ platform_init(unsigned long r3, unsigned
 =A0 =A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 strcpy(cmd_line, (char *) =

(r6 + KERNELBASE));

=A0 =A0=A0=A0=A0=A0 }

+#ifdef CONFIG_BOOKE_WDT
+=A0=A0=A0=A0 {
 +=A0=A0=A0=A0=A0=A0 extern void booke_wdt_setup_options(char =

*cmd_line);

 +
 +=A0=A0=A0=A0=A0=A0 booke_wdt_setup_options(cmd_line);
+=A0=A0=A0=A0 }
 +#endif=A0 /*=A0 CONFIG_BOOKE_WDT=A0 */
 +
 =A0 =A0=A0=A0=A0=A0 identify_ppc_sys_by_id(mfspr(SVR));

=A0 =A0=A0=A0=A0=A0 /* setup the PowerPC module struct */
 --- linux-2.6.11/arch/ppc/platforms/85xx/mpc8560_ads.c=A0 2005-03-04 =20=

17:17:54.566076736 +0900
 +++ =20
linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/mpc8560_ads.c=A0=A0=A0=A0=

=A0=A0=A0 =20

2005-03-04 13:21:31.000000000 +0900
 @@ -197,6 +197,14 @@ platform_init(unsigned long r3, unsigned
 =A0 =A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 strcpy(cmd_line, (char *) =

(r6 + KERNELBASE));

=A0 =A0=A0=A0=A0=A0 }

+#ifdef CONFIG_BOOKE_WDT
+=A0=A0=A0=A0 {
 +=A0=A0=A0=A0=A0=A0 extern void booke_wdt_setup_options(char =

*cmd_line);

 +
 +=A0=A0=A0=A0=A0=A0 booke_wdt_setup_options(cmd_line);
+=A0=A0=A0=A0 }
 +#endif=A0 /*=A0 CONFIG_BOOKE_WDT=A0 */
 +
 =A0 =A0=A0=A0=A0=A0 identify_ppc_sys_by_id(mfspr(SVR));

=A0 =A0=A0=A0=A0=A0 /* setup the PowerPC module struct */
 --- linux-2.6.11/arch/ppc/platforms/85xx/mpc85xx_cds_common.c=A0=A0 =20=

2005-03-04 17:16:27.056380232 +0900
 +++ =20
linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/mpc85xx_cds_common.c =20=

2005-03-04
13:21:31.000000000 +0900
 @@ -437,6 +437,14 @@ platform_init(unsigned long r3, unsigned
 =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 strcpy(cmd_line, =

(char *) (r6 + KERNELBASE));

=A0=A0=A0=A0=A0=A0=A0=A0=A0 }

+#ifdef CONFIG_BOOKE_WDT
+=A0=A0=A0=A0 {
 +=A0=A0=A0=A0=A0=A0 extern void booke_wdt_setup_options(char =

*cmd_line);

 +
 +=A0=A0=A0=A0=A0=A0 booke_wdt_setup_options(cmd_line);
+=A0=A0=A0=A0 }
 +#endif=A0 /*=A0 CONFIG_BOOKE_WDT=A0 */
 +
 =A0 =A0=A0=A0=A0=A0 identify_ppc_sys_by_id(mfspr(SVR));

=A0=A0=A0=A0=A0=A0=A0=A0=A0 /* setup the PowerPC module struct */
 --- linux-2.6.11/arch/ppc/platforms/85xx/sbc8560.c=A0=A0=A0=A0=A0 =

2005-03-04 =20

17:17:22.985877656 +0900
 +++ linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/sbc8560.c=A0=A0=A0 =

=20

2005-03-04 13:21:31.000000000 +0900
 @@ -198,6 +198,14 @@ platform_init(unsigned long r3, unsigned
 =A0 =A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 strcpy(cmd_line, (char *) =

(r6 + KERNELBASE));

=A0 =A0=A0=A0=A0=A0 }

+#ifdef CONFIG_BOOKE_WDT
+=A0=A0=A0=A0 {
 +=A0=A0=A0=A0=A0=A0 extern void booke_wdt_setup_options(char =

*cmd_line);

 +
 +=A0=A0=A0=A0=A0=A0 booke_wdt_setup_options(cmd_line);
+=A0=A0=A0=A0 }
 +#endif=A0 /*=A0 CONFIG_BOOKE_WDT=A0 */
 +
 =A0 =A0=A0=A0=A0=A0 identify_ppc_sys_by_id(mfspr(SVR));

=A0 =A0=A0=A0=A0=A0 /* setup the PowerPC module struct */
 --- linux-2.6.11/arch/ppc/platforms/85xx/stx_gp3.c=A0=A0=A0=A0=A0 =

2005-03-04 =20

17:14:12.883777568 +0900
 +++ linux-2.6.11-booke-wdt/arch/ppc/platforms/85xx/stx_gp3.c=A0=A0=A0 =

=20

2005-03-04 13:21:31.000000000 +0900
 @@ -68,6 +68,7 @@ unsigned long isa_mem_base =3D 0;
 =A0 unsigned long pci_dram_offset =3D 0;
 =A0 #endif

+
 =A0 /* Internal interrupts are all Level Sensitive, and Positive =20
Polarity */
 =A0 static u8 gp3_openpic_initsenses[] __initdata =3D {
 =A0 =A0=A0=A0=A0=A0 (IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE),=A0=A0=A0=

=A0=A0 /* Internal=A0 =20

0: L2 Cache */
 @@ -357,6 +358,14 @@ platform_init(unsigned long r3, unsigned
 =A0 =A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 strcpy(cmd_line, (char *) =

(r6 + KERNELBASE));

=A0 =A0=A0=A0=A0=A0 }

+#ifdef CONFIG_BOOKE_WDT
+=A0=A0=A0=A0 {
 +=A0=A0=A0=A0=A0=A0 extern void booke_wdt_setup_options(char =

*cmd_line);

 +
 +=A0=A0=A0=A0=A0=A0 booke_wdt_setup_options(cmd_line);
+=A0=A0=A0=A0 }
 +#endif=A0 /*=A0 CONFIG_BOOKE_WDT=A0 */
 +
 =A0 =A0=A0=A0=A0=A0 identify_ppc_sys_by_id(mfspr(SVR));

=A0 =A0=A0=A0=A0=A0 /* setup the PowerPC module struct */
 --- linux-2.6.11/arch/ppc/syslib/ppc4xx_setup.c 2005-03-04 =20
17:10:56.867576560 +0900
 +++ linux-2.6.11-booke-wdt/arch/ppc/syslib/ppc4xx_setup.c=A0=A0=A0=A0=A0=

=A0 =20

=3D 0;

 =A0 =A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 strcpy(cmd_line, (char *) =

(r6 + KERNELBASE));

=A0 =A0=A0=A0=A0=A0 }
 -#if defined(CONFIG_PPC405_WDT)
-/* Look for wdt=3D option on command line */
 -=A0=A0=A0=A0=A0=A0 if (strstr(cmd_line, "wdt=3D")) {
 -=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 int valid_wdt =3D 0;
 -=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 char *p, *q;
 -=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 for (q =3D cmd_line; (p =3D =

strstr(q, "wdt=3D")) !=3D 0;) {

-=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 q =3D =

p + 4;

 -=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 if (p =
cmd_line && p[-1] !=3D ' ')
 -=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =

=A0=A0=A0=A0=A0=A0=A0 continue;

-=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =

wdt_period =3D simple_strtoul(q, &q, 0);

 -=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =

valid_wdt =3D 1;

*cmd_line);

Matt,

Do you think this really needs a config option?  Should it not be =20
sufficient that if you enable watchdog you get this functionality on =20
4xx/e500?

- kumar

On Mar 4, 2005, at 3:38 AM, Takeharu KATO wrote:

=A0=A0 =20

2005-03-04 13:21:32.000000000 +0900
 @@ -346,6 +346,13 @@ config 8xx_WDT
 =A0 =A0=A0=A0=A0=A0 tristate "MPC8xx Watchdog Timer"
 =A0 =A0=A0=A0=A0=A0 depends on WATCHDOG && 8xx

+config BOOKE_WDT
 +=A0=A0=A0 bool "Book E(PowerPC 4xx/e500) Watchdog Timer"
 +=A0=A0=A0 depends on WATCHDOG && ( 4xx || E500 )
 +=A0=A0=A0 ---help---
 +=A0=A0=A0=A0=A0 This is the driver for the watchdog timers on
 +=A0=A0=A0=A0=A0 PowerPC 4xx and PowerPC e500.
 +
 =A0 # MIPS Architecture

=A0 config INDYDOG
 --- linux-2.6.11/drivers/char/watchdog/Makefile 2005-03-04 =20
17:15:30.582965496 +0900
 +++ linux-2.6.11-booke-wdt/drivers/char/watchdog/Makefile=A0=A0=A0=A0=A0=

=A0 =20

2005-03-04 13:21:32.000000000 +0900
 @@ -39,3 +39,4 @@ obj-$(CONFIG_USBPCWATCHDOG) +=3D pcwd_usb.
 =A0 obj-$(CONFIG_IXP4XX_WATCHDOG) +=3D ixp4xx_wdt.o
 =A0 obj-$(CONFIG_IXP2000_WATCHDOG) +=3D ixp2000_wdt.o
=A0 obj-$(CONFIG_8xx_WDT) +=3D mpc8xx_wdt.o
 +obj-$(CONFIG_BOOKE_WDT) +=3D booke_wdt.o
 --- linux-2.6.11/drivers/char/watchdog/booke_wdt.c=A0=A0=A0=A0=A0 =

1970-01-01 =20

09:00:00.000000000 +0900
 +++ linux-2.6.11-booke-wdt/drivers/char/watchdog/booke_wdt.c=A0=A0=A0 =

=20

2005-03-04 16:38:58.000000000 +0900
 @@ -0,0 +1,664 @@
 +/*
 + *=A0=A0=A0 Copyright (c) 2005 Fujitsu Limited
 + *
 + *=A0=A0=A0 Module name: booke_wdt.c
 + *=A0=A0=A0 Author:=A0=A0=A0=A0=A0 Takeharu =

KATO[off-list ref]

+ *
 + *=A0=A0=A0 This program is free software; you can redistribute it =

and/or

 + *=A0=A0=A0 modify it under the terms of the GNU General Public =

License

+ *=A0=A0=A0 as published by the Free Software Foundation; either =

version 2

 + *=A0=A0=A0 of the License, or (at your option) any later version.
 + *
 + *=A0=A0=A0 Neither Takeharu KATO nor Fujitsu Ltd. admit liability =

nor =20

provide
 + *=A0=A0=A0 warranty for any of this software.
 + *
 + *=A0=A0=A0 Description:
 + *=A0=A0=A0=A0 Watchdog driver for PowerPC Book E (PowerPC 4xx =

series =20

processors and
 + *=A0=A0=A0=A0 PowerPC e500 series processors).
 + *=A0=A0=A0=A0 Derived from drivers/char/watchdog/wdt.c by Alan cox
 + *=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 and=A0 =

drivers/char/watchdog/ppc405_wdt.c by Armin =20

Kuster.
 + *=A0=A0=A0=A0 PPC4xx WDT operation is driverd from Appendix of
 + *=A0=A0=A0=A0 PowerPC Embedded Processors Application Note
 + *=A0=A0=A0=A0=A0 ``PowerPC 40x Watch Dog Timer'' published from =

IBM.

 + *=A0=A0=A0=A0 This driver is written according to ``PowerPC e500 =

Core =20

Complex
 + *=A0=A0=A0=A0 Reference Manual'' for e500 part.
 + */
 +#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
 +#include <linux/reboot.h>
+#include <linux/init.h>
 +#include <linux/capability.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <asm/reg.h>
 +#include <asm/uaccess.h>
+#include <asm/system.h>
+#include "booke_wdt.h"
+
 +/* micro seconds per one milli-second(used to calculatewatchdog
+ * counter to be set). */
 +#define US_PER_MS 1000
 +/*=A0 Calculate watchdog count=A0=A0 */
 +#define calculate_wdt_count(t) ((((unsigned long)(t))*HZ)/1000)
+
 +int wdt_enable=3D0;=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 /* WDT start =

on boot=A0 */

intrrupt counter to be =20

reloaded */
 +static volatile int wdt_heartbeat_count =3D 0;=A0 /* WDT intrrupt =20=

counter(compatible mode)*/
 +static unsigned long driver_state; /* Driver status (see: =20
booke_wdt.h) */
 +/*
 + *=A0 Identifier for this watchdog
 + */
 +static struct watchdog_info ident =3D {
 +=A0 .options=3DWDIOF_SETTIMEOUT|WDIOF_KEEPALIVEPING|WDIOF_MAGICCLOSE,
+=A0 .firmware_version =3D=A0=A0=A0 0, /*=A0 This is filled with PVR =

in =20

initialization. */
 +=A0 .identity =3D=A0=A0=A0=A0=A0=A0=A0 "Book E(PPC 4xx/e500) WDT",
 +};
 +
 +/*
 + *=A0 PowerPC Linux common exception handler
 + */
 +extern void _exception(int signr, struct pt_regs *regs, int code, =20=

unsigned long addr);
 +/*=A0 Panic notifier=A0 */
 +extern struct notifier_block *panic_notifier_list;
+/*
 + *=A0 External linkage functions
 + */
 +void booke_wdt_heartbeat(void);
+void booke_wdt_setup_options(char *cmd_line);
 +void booke_wdt_exception(struct pt_regs *regs);
+/*
 + * Internal linkage functions
 + */
 +static __inline__ void __booke_wdt_setup_val(int period,int reset);
 +static __inline__ void __booke_wdt_enable(void);
+static __inline__ void __booke_wdt_disable(void);
+static __inline__ int=A0 __booke_wdt_is_enabled(void);
+static __inline__ void __booke_wdt_clear_int_stat(void);
+static __inline__ void __booke_wdt_set_timeout(int t);
 +static __inline__ void booke_wdt_init_device(void);
+static __inline__ int=A0 booke_wdt_is_enabled(void);
+static __inline__ int=A0 booke_wdt_start(void);
+static __inline__ int=A0 booke_wdt_stop(void);
+static __inline__ int=A0 booke_wdt_ping(void);
+static __inline__ int=A0 booke_wdt_set_timeout(int t);
 +static __inline__ int=A0 booke_wdt_get_status(int *status);
 +static ssize_t booke_wdt_write(struct file *file, const char *buf, =20=

size_t count, loff_t *ppos);
 +static int booke_wdt_ioctl(struct inode *inode, struct file *file, =20=

unsigned int cmd,unsigned long arg);
 +static int booke_wdt_open(struct inode *inode, struct file *file);
+static int booke_wdt_release(struct inode *inode, struct file *file);
+static int booke_wdt_notify_sys(struct notifier_block *this, unsigned =

=20

long code,void *unused);
 +static int __init booke_wdt_init(void);
+static void __exit booke_wdt_exit(void);
+
 +/*
 + *=A0=A0=A0 Watchdog operations on PPC4xx/e500 MPU
 + */
 +
 +/**
 + *=A0=A0=A0=A0=A0 __booke_wdt_setup_val
+ *=A0=A0=A0=A0=A0 Enable Watchdog, sets up passed in values for =

TCR[WP],

 + *=A0=A0=A0=A0=A0 TCR[WRC]
 + *
 + *=A0=A0=A0 @period:=A0=A0=A0 Input Watchdog Period - TCR[WP]
 + *=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 0 =

=3D 217 clocks

+ *=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 1 =3D=

221 clocks

+ *=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 2 =3D=

225 clocks

+ *=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 3 =3D=

229 clocks

+ *=A0=A0=A0=A0=A0 @reset:=A0=A0=A0=A0=A0=A0=A0=A0 Watchdog reset =

control - TCR[WRC]

 + *=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 0 =

=3D No reset

 + *=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 1 =

=3D PPC Core reset only

 + *=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 2 =

=3D PPC Chip reset

 + *=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 3 =

=3D System reset

 + *=A0=A0=A0=A0 Note: The meaning of period number is differ PPC440GP =

from =20

PPC440GX.
 + */
 +#if defined(CONFIG_4xx)
+static __inline__ void
+__booke_wdt_setup_val(int period,int reset)
 +{
 +=A0 unsigned long val;
 +
 +=A0 /*=A0 Set up TCR=A0 */
 +=A0 =20
=

val=3D((period)<<WDT_TCR_WP_SHIFT|(reset)<<WDT_TCR_WRC_SHIFT)|mfspr(SPRN_=20=

TCR);
+=A0 /*=A0 Disable WDT=A0 */
 +=A0 val &=3D ~(WDT_TCR_WDT_ENABLE);
+
 +=A0 mtspr(SPRN_TCR,val);
+}
 +#else
 +/*=A0 e500=A0 */
 +static __inline__ void
+__booke_wdt_setup_val(int period,int reset)
 +{
 +=A0 unsigned long val;
 +=A0 /*=A0 Set up TCR=A0 */
 +
 +=A0 val=3D(((period)&(WDT_TCR_WP_BITMSK)) << WDT_TCR_WP_SHIFT|
+=A0=A0=A0=A0=A0=A0 ( ( (period) >> 2 )&(WDT_TCR_WPEXT_BITMSK)) << =20
WDT_TCR_WPEXT_SHIFT|
+=A0=A0=A0=A0=A0=A0 (reset)<<WDT_TCR_WRC_SHIFT)|mfspr(SPRN_TCR);
+=A0 /*=A0 Disable WDT=A0 */
 +=A0 val &=3D ~(WDT_TCR_WDT_ENABLE);
+
 +=A0 mtspr(SPRN_TCR,val);
+}
 +#endif=A0 /*=A0 CONFIG_E500 */
 +/**
 + *=A0=A0=A0=A0=A0 __booke_wdt_enable
+ *=A0=A0=A0=A0=A0 Enable Watchdog
 + */
 +static __inline__ void
+__booke_wdt_enable(void)
+{
 +=A0 mtspr(SPRN_TCR,(mfspr(SPRN_TCR)|WDT_TCR_WDT_ENABLE));
+}
 +/**
 + *=A0=A0=A0=A0=A0 __booke_wdt_disable
+ *=A0=A0=A0=A0=A0 Disable Watchdog
 + */
 +static __inline__ void
+__booke_wdt_disable(void)
+{
 +=A0 mtspr(SPRN_TCR,(mfspr(SPRN_TCR)&(~(WDT_TCR_WDT_ENABLE))));
+}
 +/**
 + *=A0=A0=A0=A0=A0 __booke_wdt_is_enabled
+ *=A0=A0=A0=A0=A0 Check whether Watchdog is enabled.
 + */
 +static __inline__ int
 +__booke_wdt_is_enabled(void)
+{
 +=A0 return (mfspr(SPRN_TCR) & WDT_TCR_WDT_ENABLE);
+}
 +/**
 + *=A0=A0=A0=A0=A0 __booke_wdt_clear_init_stat
+ *=A0=A0=A0=A0=A0 Clear interrupt status of watchdog to ping it.
 + */
 +static __inline__ void
+__booke_wdt_clear_int_stat(void)
+{
 +=A0 mtspr(SPRN_TSR, (TSR_ENW|TSR_WIS));
+}
 +/**
 + *=A0=A0=A0 __booke_wdt_set_timeout:
+ *=A0=A0=A0 @t:=A0=A0=A0 the new time out value that needs to be set.
 + *
 + *=A0=A0=A0 Set a new time out value for the watchdog device.
 + *
 + */
 +static __inline__ void
+__booke_wdt_set_timeout(int t)
 +{
 +=A0 wdt_count=3Dcalculate_wdt_count(t);
+=A0 return;
 +}
 +
 +/*
 + * Driver specific functions
 + */
 +
 +/**
 + *=A0=A0 booke_wdt_setup_options
+ *=A0=A0 @cmd_line : a pointer to kernel command line.
+ *
 + */
 +void
 +booke_wdt_setup_options(char *cmd_line)
 +{
 +/*
 + * Look for wdt=3D option on command line
 + */
 +=A0 if (strstr(cmd_line, "wdt=3D")) {
 +=A0=A0=A0 int valid_wdt =3D 0;
 +=A0=A0=A0 char *p, *q;
+
 +=A0=A0=A0 for (q =3D cmd_line; (p =3D strstr(q, "wdt=3D")) !=3D 0;) =

{

%s\n",

 +=A0=A0=A0=A0=A0=A0=A0 regs->nip, regs->msr, regs->trap, =

print_tainted());

=20

bother reloading
 + *=A0=A0=A0 the cascade counter.
 + */
 +static __inline__ int
 +booke_wdt_ping(void)
+{
 +=A0 /* Disable watchdog */
 +=A0 __booke_wdt_disable();
+=A0 /* Write a watchdog value */
 +=A0 __booke_wdt_clear_int_stat();
+=A0 /*=A0 Reset count=A0 */
 +=A0 wdt_heartbeat_count=3Dwdt_count;
+=A0 /* Enable watchdog */
 +=A0 __booke_wdt_enable();
+
 +=A0 return 0;
 +}
 +/**
 + *=A0=A0=A0 booke_wdt_set_timeout:
+ *=A0=A0=A0 @t:=A0=A0=A0=A0=A0=A0=A0 the new timeout value that needs =

to be set.

 + *
 + *=A0=A0=A0 Set a new time out value for the watchdog device.
 + *=A0=A0=A0=A0=A0 If the heartbeat value is incorrect we keep the =

old value

facility.

number.

here

 + *=A0=A0=A0 @count: count of bytes
 + *=A0=A0=A0 @ppos: pointer to the position to write. No seeks =

allowed

 + *
 + *=A0=A0=A0 A write to a watchdog device is defined as a keepalive =

signal. =20

Any
 + *=A0=A0=A0 write of data will do, as we we don't define content =

meaning =20

expept
 + *=A0=A0=A0=A0=A0 'V' character. It is performed as a sign to set =20=

stop-on-close mode.
 + */
 +
 +static ssize_t
 +booke_wdt_write(struct file *file, const char *buf, size_t count, =20=

loff_t *ppos)
 +{
 +=A0 size_t i;
 +
 +=A0=A0=A0 if (!nowayout) {
 +=A0=A0=A0=A0=A0 /* In case it was set long ago */
 +=A0=A0=A0=A0=A0 clear_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state);
+
 +=A0=A0=A0=A0=A0 for (i =3D 0; i < count; i++) {
+=A0=A0=A0 char c;
 +
 +=A0=A0=A0 if (get_user(c, buf + i))
 +=A0=A0=A0=A0=A0 return -EFAULT;
 +
 +=A0=A0=A0 if (c =3D=3D 'V') {
 +=A0=A0=A0=A0=A0 set_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state);
+=A0=A0=A0 }
 +=A0=A0=A0=A0=A0 }
 +=A0=A0=A0 }
 +=A0=A0=A0 booke_wdt_ping();
+
 +=A0 return count;
 +}
 +
 +/**
 + *=A0=A0=A0 booke_wdt_ioctl:
+ *=A0=A0=A0 @inode: inode of the device
 + *=A0=A0=A0 @file: file handle to the device
 + *=A0=A0=A0 @cmd: watchdog command
 + *=A0=A0=A0 @arg: argument pointer
 + *
 + */
 +static int
 +booke_wdt_ioctl(struct inode *inode, struct file *file, unsigned int =

=20

cmd,
 +=A0=A0=A0 unsigned long arg)
 +{
 +=A0=A0=A0 int new_timeout;
 +=A0=A0=A0 int status;
 +
 +=A0=A0=A0 if (!capable(CAP_SYS_ADMIN))
+=A0=A0=A0=A0=A0=A0=A0 return -EPERM;=A0 /*=A0 It may be too strict =

manner.=A0 */

&ident, =20

sizeof(struct watchdog_info)))
+=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 return -EFAULT;
 +=A0=A0=A0=A0=A0=A0=A0 else
 +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 break;
 +=A0=A0=A0 case WDIOC_GETSTATUS:
+=A0=A0=A0=A0=A0=A0=A0 booke_wdt_get_status(&status);
+=A0=A0=A0=A0=A0=A0=A0 return put_user(status,(int *)arg);
 +=A0=A0=A0 case WDIOC_KEEPALIVE:
+=A0=A0=A0=A0=A0=A0=A0 booke_wdt_ping();
+=A0=A0=A0=A0=A0=A0=A0 break;
 +=A0=A0=A0 case WDIOC_SETTIMEOUT:
+=A0=A0=A0=A0=A0=A0=A0 if (get_user(new_timeout, (int *)arg))
 +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 return -EFAULT;
 +=A0=A0=A0=A0=A0=A0=A0 if (booke_wdt_set_timeout(new_timeout))
+=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 return -EINVAL;
 +=A0=A0=A0=A0=A0=A0=A0 booke_wdt_ping();
+=A0=A0=A0=A0=A0=A0=A0 break;
 +=A0=A0=A0 case WDIOC_GETTIMEOUT:
+=A0=A0=A0=A0=A0=A0=A0 return put_user(wdt_period, (int *)arg);
 +=A0=A0=A0 case WDIOC_SETOPTIONS:
+=A0=A0=A0=A0=A0=A0=A0 if (get_user(status, (int *)arg))
 +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 return -EFAULT;
 +=A0=A0=A0=A0=A0=A0=A0 /*=A0 Return -EINVAL when the driver can not =

figure out

 +=A0=A0=A0=A0=A0=A0=A0=A0 *=A0 what it should do. Unknown cases are =

just ignored.

 +=A0=A0=A0=A0=A0=A0=A0=A0 */
 +=A0=A0=A0=A0=A0=A0=A0 if ( (status & =

(WDIOS_DISABLECARD|WDIOS_ENABLECARD))

+=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =3D=3D =

(WDIOS_DISABLECARD|WDIOS_ENABLECARD) )

disabled\n");

enabled\n");

is =20

single
+ *=A0=A0=A0 open and start the WDT timer.
 + */
 +static int
 +booke_wdt_open(struct inode *inode, struct file *file)
 +{
 +=A0=A0=A0 if (!capable(CAP_SYS_ADMIN))
+=A0=A0=A0=A0=A0=A0=A0 return -EPERM;
 +
 +=A0=A0=A0 if (test_and_set_bit(WDT_STATE_OPEN, &driver_state))
+=A0=A0=A0=A0=A0=A0=A0 return -EBUSY;
 +=A0=A0=A0 /*
 +=A0=A0=A0=A0 * Activate
 +=A0=A0=A0=A0 */
 +=A0=A0=A0 booke_wdt_start();
+=A0=A0=A0 wdt_enable=3D1;
+
 +=A0=A0=A0 if (nowayout)
 +=A0=A0=A0=A0=A0 set_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state);
+
 +=A0=A0=A0 return 0;
 +}
 +
 +/**
 + *=A0=A0=A0 booke_wdt_release:
+ *=A0=A0=A0 @inode: inode to board
+ *=A0=A0=A0 @file: file handle to board
 + *
 + */
 +static int
 +booke_wdt_release(struct inode *inode, struct file *file)
 +{
 +=A0 if (test_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state)) {
 +=A0=A0=A0=A0=A0 booke_wdt_note("WDT device is stopped.\n");
 +=A0=A0=A0 booke_wdt_stop();
+=A0=A0=A0 wdt_enable=3D0;
+=A0 } else {
 +=A0=A0=A0 if ( (booke_wdt_is_enabled()) && (!nowayout) ) {
 +=A0=A0=A0=A0=A0 booke_wdt_note("WDT device may be closed =

unexpectedly.=A0 WDT =20

will not stop!\n");
 +=A0=A0=A0=A0=A0 booke_wdt_ping();
+=A0=A0=A0 }
 +=A0 }
 +=A0 clear_bit(WDT_STATE_OPEN, &driver_state);
+
 +=A0 return 0;
 +}
 +/**
 + *=A0=A0=A0 notify_sys:
 + *=A0=A0=A0 @this: our notifier block
 + *=A0=A0=A0 @code: the event being reported
+ *=A0=A0=A0 @unused: unused
 + *=A0=A0=A0 Note: This function assume that the panic notifier is =

called =20

with CODE=3D0
 + *=A0=A0=A0=A0=A0=A0=A0=A0=A0 (see panic function in =

kernel/panic.c).

code,

you =20

unload
 + *=A0=A0=A0 it, well it keeps ticking.=A0 You just have to load a =

new

 + *=A0=A0=A0 module in 60 seconds or reboot.
 + *=A0=A0=A0=A0=A0 This behavior(more over the comments as above) is =

borrowed =20

from
 + *=A0=A0=A0=A0=A0 Alan cox's driver.
 + */
 +
 +static void __exit
 +booke_wdt_exit(void)
+{
 +=A0=A0=A0 misc_deregister(&booke_wdt_miscdev);
+=A0=A0=A0 unregister_reboot_notifier(&booke_wdt_notifier);
+=A0=A0=A0 =20
notifier_chain_unregister(&panic_notifier_list,&booke_wdt_notifier);
+}
 +
 +/**
 + *=A0=A0=A0=A0 booke_wdt_init:
+ *
 + *=A0=A0=A0 Set up the WDT relevant timer facility.
 + */
 +
 +static int __init
 +booke_wdt_init(void)
+{
 +=A0=A0=A0 int ret;
 +=A0=A0=A0 unsigned long flags;
 +
 +=A0=A0=A0 ret =3D register_reboot_notifier(&booke_wdt_notifier);
+=A0=A0=A0 if(ret) {
 +=A0=A0=A0=A0=A0 booke_wdt_err("Cannot register reboot notifier =

(err=3D%d)\n", =20

ret);
 +=A0=A0=A0=A0=A0 return ret;
+=A0=A0=A0 }
 +
 +=A0=A0=A0 /* Register panic notifier=A0 */
 +=A0=A0=A0 ret =3D =20
notifier_chain_register(&panic_notifier_list,&booke_wdt_notifier);
+=A0=A0=A0 if(ret) {
 +=A0=A0=A0=A0=A0 booke_wdt_err("Cannot register panic notifier =

(err=3D%d)\n", =20

ret);
 +=A0=A0=A0=A0=A0 unregister_reboot_notifier(&booke_wdt_notifier);
+=A0=A0=A0=A0=A0 return ret;
+=A0=A0=A0 }
 +
 +=A0=A0=A0 ret =3D 0;
 +=A0=A0=A0 booke_wdt_init_device();
+=A0=A0=A0 /* Check that the heartbeat value is within it's range ; if =

not =20

reset to the default */
 +=A0=A0=A0 if (booke_wdt_set_timeout(wdt_period)) {
 +=A0=A0=A0=A0=A0 if (wdt_period)
 +=A0=A0=A0=A0=A0=A0=A0 booke_wdt_info("The heartbeat value must be %d =

< wdt_period =20

< %d, using
%d\n",WDT_HEARTBEAT_MIN,WDT_HEARTBEAT_MAX,WDT_TIMO);
+=A0=A0=A0=A0=A0 booke_wdt_set_timeout(WDT_TIMO);
+=A0=A0=A0 }
 +
 +=A0=A0=A0 local_irq_save(flags); /* Prevent timer interrupt */
 +=A0=A0=A0 ppc_md.heartbeat_count =3D 0;
 +=A0=A0=A0 ppc_md.heartbeat=3Dbooke_wdt_heartbeat;
+=A0=A0=A0 local_irq_restore(flags);
+
 +=A0=A0=A0 booke_wdt_info("Book E(PPC 4xx/e500) Watchdog Driver. =

period=3D%d =20

ms (nowayout=3D%d)\n",wdt_period,
 nowayout);
 +
 +=A0=A0=A0 ret =3D misc_register(&booke_wdt_miscdev);
+=A0=A0=A0 if (ret) {
 +=A0=A0=A0=A0=A0 booke_wdt_err("Cannot register miscdev on minor=3D%d =

(err=3D%d)\n",

1970-01-01 =20

09:00:00.000000000 +0900
 +++ linux-2.6.11-booke-wdt/drivers/char/watchdog/booke_wdt.h=A0=A0=A0 =

=20

2005-03-04 16:38:58.000000000 +0900
 @@ -0,0 +1,125 @@
 +/*
 + *
 + *=A0=A0=A0 Copyright (c) 2004 Fujitsu Limited
 + *
 + *=A0=A0=A0 Module name: booke_wdt.h
 + *=A0=A0=A0 Author:=A0=A0=A0=A0=A0 Takeharu =

KATO[off-list ref]

+ *=A0=A0=A0 Description:
 + *=A0=A0=A0=A0=A0 Header file for PowerPC Book E(PPC 4xx/e500) =

watchdog driver.

 + *
 + *=A0=A0=A0 This program is free software; you can redistribute it =

and/or

 + *=A0=A0=A0 modify it under the terms of the GNU General Public =

License

+ *=A0=A0=A0 as published by the Free Software Foundation; either =

version 2

 + *=A0=A0=A0 of the License, or (at your option) any later version.
 + *
 + *=A0=A0=A0 Neither Takeharu KATO nor Fujitsu Ltd. admit liability =

nor =20

provide
 + *=A0=A0=A0 warranty for any of this software.
 + *
 + */
 +#ifndef _DRIVERS_CHAR_WATCHDOG_BOOKE_WDT_H
+#define _DRIVERS_CHAR_WATCHDOG_BOOKE_WDT_H
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/watchdog.h>
+
 +/*
 + *=A0 Driver state flags(bit position)
 + */
 +#define WDT_STATE_OPEN=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=

=A0 0=A0=A0 /* driver is opend=A0 */

 +#define WDT_STATE_STOP_ON_CLOSE=A0=A0=A0=A0=A0=A0=A0=A0 1=A0=A0 /* =

Stop with close is =20

expected */
 +/*
 + * Configurations
+ */
 +#define WDT_TIMO=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 60000=A0=A0=A0 /* =

Default timeout =3D 60000 =20

ms(1min) */
 +#define WDT_HEARTBEAT_MIN=A0 100=A0=A0=A0=A0=A0=A0=A0=A0=A0 /* =

Minimum timeout =3D 100 ms =20

*/
 +#define WDT_HEARTBEAT_MAX=A0 600000=A0=A0=A0=A0=A0=A0 /* Maximum =

timeout =3D =20

600000ms(1hour) */
 +#ifdef __KERNEL__
 +//#define BOOKE_WDT_DEBUG=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=

=A0=A0=A0=A0=A0 /*=A0 Debug switch */

(bit[0..1])=A0=A0 */

 +#define WDT_TCR_WRC_BIT=A0=A0=A0 3=A0=A0 /*=A0 WRC bit in TCR =

(bit[2..3])=A0=A0 */

 +#define WDT_TCR_WIE_BIT=A0=A0=A0 4=A0=A0 /*=A0 WIE bit in TCR =

(bit[4])=A0=A0=A0=A0=A0 */

booke_wdt.c.

WDT_WP3

 +
 +/*
 + *=A0 IOCTL commands for comaptiblity for old driver
 + */
 +#define WDIOC_GETPERIOD=A0=A0=A0=A0=A0=A0=A0=A0 WDIOC_GETTIMEOUT
+#define WDIOC_SETPERIOD=A0=A0=A0=A0=A0=A0=A0=A0 WDIOC_SETTIMEOUT
+
 +/*
 + *=A0 output messages
 + */
 +#define __BOOKE_WDT_MSG "BookE-WDT : "
 +#define booke_mkmsg(str) __BOOKE_WDT_MSG str
 +#define booke_wdt_info(fmt,arg...) \
 +=A0=A0=A0 printk(KERN_INFO __BOOKE_WDT_MSG fmt,##arg)
 +#define booke_wdt_note(fmt,arg...) \
 +=A0=A0=A0 printk(KERN_NOTICE __BOOKE_WDT_MSG fmt,##arg)
 +#define booke_wdt_err(fmt,arg...) \
 +=A0=A0=A0 printk(KERN_ALERT __BOOKE_WDT_MSG fmt,##arg)
 +#define booke_wdt_crit(fmt,arg...) \
 +=A0=A0=A0 printk(KERN_ALERT __BOOKE_WDT_MSG fmt,##arg)
 +#if defined(BOOKE_WDT_DEBUG)
+#define booke_wdt_dbg(fmt,arg...) \
 +=A0=A0=A0 printk(KERN_ALERT __BOOKE_WDT_MSG fmt,##arg)
 +#else
 +#define booke_wdt_dbg(fmt,arg...) \
 +=A0=A0=A0=A0=A0=A0=A0 do{}while(0)
 +#endif=A0 /*=A0 WDT_DEBUG=A0 */
 +
 +#endif=A0 /* __KERNEL__=A0 */
 +#endif=A0 /*=A0 _DRIVERS_CHAR_WATCHDOG_BOOKE_WDT_H=A0 */

=20=

On Fri, 2005-03-04 at 18:38 +0900, Takeharu KATO wrote:

Hi Takeharu,

Some comments below.  Looks good overall.

This is slightly wrong.  Not all 4xx processors are BOOKE.  403 and 405
aren't to be specific.  But it's not really that big of a deal I guess.

Couldn't you just use the #ifdef in the release function and not
"disable" the watchdog?  It would save a global variable at least.

If you order these in the right way, you don't need to declare them in
advance.

These two functions are somewhat misleading.  On 4xx the timer is
essentially always enabled.  The bit you are setting and clearing here
is just to enable the exception after the expiration of the 2nd WP.  The
reason I bring this up is because if you ever set TCR[WRC] to something
non-zero and this bit is off, the processor will just be reset after 3
watchdog periods.  In other words, if TCR[WRC] is ever non-zero there is
no such thing as disabling the timer.  You will always need to do the
ping to keep the processor from resetting.

This is effectively "stop getting the interrupt" on 4xx for the reasons
I said above.

Since you're using WDT_RESET_NONE, I think what you have here should
work.  

Most of this is in include/asm-ppc/reg_booke.h.  Could you use that
instead of redefining most of it?

In include/linux/device.h there are dev_printk and dev_dbg macros that
do pretty much the same thing.  Could you use those instead?

Overall I think you have a good heartbeat style driver.  Just watch out
if you ever add an ioctl to set the reset type to something other than
none ;).

josh

Dear Josh:

Thank you for your thorough review.

Josh Boyer wrote:

This is slightly wrong.  Not all 4xx processors are BOOKE.  403 and 405
aren't to be specific.  But it's not really that big of a deal I guess.

I know this.
As you said, I regard this with minor thing.

quoted

+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif

Couldn't you just use the #ifdef in the release function and not
"disable" the watchdog?  It would save a global variable at least.

At first, I examined to remove the release file operation
to eliminate this global variable.
On second thought, I decided to use this global variable as drivers/char/watchdog/wdt.c.
I think that the release file operation is necessary to control
so as not to open the device more than twice.
This behavior is commonly used in other watch dog drivers,
doesn't it?

quoted

+static int __init booke_wdt_init(void);
+static void __exit booke_wdt_exit(void);

If you order these in the right way, you don't need to declare them in
advance.

Ok, I'll remove them.

quoted

+/**
+ *      __booke_wdt_enable
+ *      Enable Watchdog
+ */
+static __inline__ void
+__booke_wdt_enable(void)
+{
+  mtspr(SPRN_TCR,(mfspr(SPRN_TCR)|WDT_TCR_WDT_ENABLE));
+}
+/**
+ *      __booke_wdt_disable
+ *      Disable Watchdog
+ */
+static __inline__ void
+__booke_wdt_disable(void)
+{
+  mtspr(SPRN_TCR,(mfspr(SPRN_TCR)&(~(WDT_TCR_WDT_ENABLE))));
+}

These two functions are somewhat misleading.  On 4xx the timer is
essentially always enabled.  The bit you are setting and clearing here
is just to enable the exception after the expiration of the 2nd WP.  The
reason I bring this up is because if you ever set TCR[WRC] to something
non-zero and this bit is off, the processor will just be reset after 3
watchdog periods.  In other words, if TCR[WRC] is ever non-zero there is
no such thing as disabling the timer.  You will always need to do the
ping to keep the processor from resetting.

 I agree that function names like XXX_wdt_enable(or disable) are not
reflected on precise meaning.

But in this driver, we set TCR[WRC] as zero.It is needed to detect and logging WDT timeout with software before MPU reset. I want to leave the way to find where the system hang up.
IMHO, this is the reason to use WDT in the system.
So, I will not support non-zero TCR[WRC].

From the above-mentioned viewpoint, making WDT exception enabled (or disabled) means start/stop WDT itself in this driver.
This is the reason to adopt these names.

Please note that the system will panic before the CPU attempt to reset CPU when we use this driver.

Please let me hear it if there are some opinions.

Since you're using WDT_RESET_NONE, I think what you have here should
work. 

Yes, however, it is implemented on purpose.

quoted

+/*
+ *  WP relevant values used in our driver.
+ *  Note:WDT period must be more than HZ(Timer ticks)
+ */
+#define WDT_WP                 WDT_WP3

Most of this is in include/asm-ppc/reg_booke.h.  Could you use that
instead of redefining most of it?

To tell the truth, this matter has been examined, but I forgot this.
Thank you for making it recall(^^

In include/linux/device.h there are dev_printk and dev_dbg macros that
do pretty much the same thing.  Could you use those instead?

I did not know such thing.
I'll try to use them.

Regards,

-- 
Takeharu KATO

Hi, Josh:

Takeharu KATO wrote:

quoted

Most of this is in include/asm-ppc/reg_booke.h.  Could you use that
instead of redefining most of it?

To tell the truth, this matter has been examined, but I forgot this.
Thank you for making it recall(^^

I performed minor fixes which you pointed out.
But I leaves WDT_WP[0123] on purpose.
The interpretation of this value is different between PPC4xx and e500.
To unite them, I leaves this.

quoted

In include/linux/device.h there are dev_printk and dev_dbg macros that
do pretty much the same thing.  Could you use those instead?

I did not know such thing.
I'll try to use them.

On second thought, I found that it is not so good idea.
If I change this according to what you said, it is not
easy to find which driver outputs messages when we can
use multiple WDT in a system.

Macros in include/linux/device.h will use name member in miscdevice struct as driver's name, and this is commonly named as "watchdog".

FYI, I show the difference with the patch submitted last time.


Regards,I'll test this driver today, just in case, before I post the revised edition of this driver.

Regards,

-- 
Takeharu KATO

On Mon, 2005-03-07 at 04:15 +0900, Takeharu KATO wrote:

Hi, Josh:

Takeharu KATO wrote:

quoted

quoted

To tell the truth, this matter has been examined, but I forgot this.
Thank you for making it recall(^^

I performed minor fixes which you pointed out.
But I leaves WDT_WP[0123] on purpose.
The interpretation of this value is different between PPC4xx and e500.
To unite them, I leaves this.

Ok, that makes sense.

quoted

quoted

In include/linux/device.h there are dev_printk and dev_dbg macros that
do pretty much the same thing.  Could you use those instead?

I did not know such thing.
I'll try to use them.

On second thought, I found that it is not so good idea.
If I change this according to what you said, it is not
easy to find which driver outputs messages when we can
use multiple WDT in a system.

Macros in include/linux/device.h will use name member in miscdevice 
struct as driver's name, and this is commonly named as "watchdog".

Ok, that's fine too.  No complaints here.