Commit fb64c244 authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Paul Mackerras
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[PATCH] ppc32: m8xx watchdog update 



This updates m8xx_wdt as follows:

1) Remove now obsolete fpos check in the write() function. The driver is
currently non functional due to this bug.

2) Use in/out macros for register access.

3) Allows m8xx_wdt to use a kernel timer instead of the builtin RTC/PIT
for keep-alive trigger (which is responsible for servicing the watchdog
until an userspace application takes over). For instance Cyclades PRxK
boards (MPC 855T based) have a non-functional internal RTC/PIT unit.
Behaviour for boards with RTC/PIT is unchaged.

4) The last change required moving the RTCSC register setting code
to a weak function which can be overriden by board specific files.
Otherwise the timer init code trashes the register making it impossible
for m8xx_wdt to detect the situation.

Signed-off-by: default avatarMarcelo Tosatti <marcelo.tosatti@cyclades.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 623703f6

arch/ppc/syslib/m8xx_setup.c

+11 −4
Original line number Diff line number Diff line
@@ -135,6 +135,16 @@ static struct irqaction tbint_irqaction = { 
	.name = "tbint",

};



/* per-board overridable init_internal_rtc() function. */

void __init __attribute__ ((weak))

init_internal_rtc(void)

{

	/* Disable the RTC one second and alarm interrupts. */

	out_be16(&((immap_t *)IMAP_ADDR)->im_sit.sit_rtcsc, in_be16(&((immap_t *)IMAP_ADDR)->im_sit.sit_rtcsc) & ~(RTCSC_SIE | RTCSC_ALE));

	/* Enable the RTC */

	out_be16(&((immap_t *)IMAP_ADDR)->im_sit.sit_rtcsc, in_be16(&((immap_t *)IMAP_ADDR)->im_sit.sit_rtcsc) | (RTCSC_RTF | RTCSC_RTE));

}



/* The decrementer counts at the system (internal) clock frequency divided by

 * sixteen, or external oscillator divided by four.  We force the processor

 * to use system clock divided by sixteen.
@@ -183,10 +193,7 @@ void __init m8xx_calibrate_decr(void) 
	out_be32(&((immap_t *)IMAP_ADDR)->im_sitk.sitk_rtcsck, KAPWR_KEY);

	out_be32(&((immap_t *)IMAP_ADDR)->im_sitk.sitk_tbk, KAPWR_KEY);



	/* Disable the RTC one second and alarm interrupts. */

	out_be16(&((immap_t *)IMAP_ADDR)->im_sit.sit_rtcsc, in_be16(&((immap_t *)IMAP_ADDR)->im_sit.sit_rtcsc) & ~(RTCSC_SIE | RTCSC_ALE));

	/* Enable the RTC */

	out_be16(&((immap_t *)IMAP_ADDR)->im_sit.sit_rtcsc, in_be16(&((immap_t *)IMAP_ADDR)->im_sit.sit_rtcsc) | (RTCSC_RTF | RTCSC_RTE));

	init_internal_rtc();



	/* Enabling the decrementer also enables the timebase interrupts

	 * (or from the other point of view, to get decrementer interrupts

arch/ppc/syslib/m8xx_wdt.c

+67 −25
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <syslib/m8xx_wdt.h>



static int wdt_timeout;

int m8xx_has_internal_rtc = 0;



static irqreturn_t m8xx_wdt_interrupt(int, void *, struct pt_regs *);

static struct irqaction m8xx_wdt_irqaction = {
@@ -45,35 +46,15 @@ static irqreturn_t m8xx_wdt_interrupt(int irq, void *dev, struct pt_regs *regs) 
	return IRQ_HANDLED;

}



void __init m8xx_wdt_handler_install(bd_t * binfo)

#define SYPCR_SWP 0x1

#define SYPCR_SWE 0x4





void __init m8xx_wdt_install_irq(volatile immap_t *imap, bd_t *binfo)

{

	volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;

	u32 pitc;

	u32 sypcr;

	u32 pitrtclk;



	sypcr = in_be32(&imap->im_siu_conf.sc_sypcr);



	if (!(sypcr & 0x04)) {

		printk(KERN_NOTICE "m8xx_wdt: wdt disabled (SYPCR: 0x%08X)\n",

		       sypcr);

		return;

	}



	m8xx_wdt_reset();



	printk(KERN_NOTICE

	       "m8xx_wdt: active wdt found (SWTC: 0x%04X, SWP: 0x%01X)\n",

	       (sypcr >> 16), sypcr & 0x01);



	wdt_timeout = (sypcr >> 16) & 0xFFFF;



	if (!wdt_timeout)

		wdt_timeout = 0xFFFF;



	if (sypcr & 0x01)

		wdt_timeout *= 2048;



	/*

	 * Fire trigger if half of the wdt ticked down 

	 */
@@ -98,6 +79,67 @@ void __init m8xx_wdt_handler_install(bd_t * binfo) 
	printk(KERN_NOTICE

	       "m8xx_wdt: keep-alive trigger installed (PITC: 0x%04X)\n", pitc);



}



static void m8xx_wdt_timer_func(unsigned long data);



static struct timer_list m8xx_wdt_timer =

	TIMER_INITIALIZER(m8xx_wdt_timer_func, 0, 0);



void m8xx_wdt_stop_timer(void)

{

	del_timer(&m8xx_wdt_timer);

}



void m8xx_wdt_install_timer(void)

{

	m8xx_wdt_timer.expires = jiffies + (HZ/2);

	add_timer(&m8xx_wdt_timer);

}



static void m8xx_wdt_timer_func(unsigned long data)

{

	m8xx_wdt_reset();

	m8xx_wdt_install_timer();

}



void __init m8xx_wdt_handler_install(bd_t * binfo)

{

	volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;

	u32 sypcr;



	sypcr = in_be32(&imap->im_siu_conf.sc_sypcr);



	if (!(sypcr & SYPCR_SWE)) {

		printk(KERN_NOTICE "m8xx_wdt: wdt disabled (SYPCR: 0x%08X)\n",

		       sypcr);

		return;

	}



	m8xx_wdt_reset();



	printk(KERN_NOTICE

	       "m8xx_wdt: active wdt found (SWTC: 0x%04X, SWP: 0x%01X)\n",

	       (sypcr >> 16), sypcr & SYPCR_SWP);



	wdt_timeout = (sypcr >> 16) & 0xFFFF;



	if (!wdt_timeout)

		wdt_timeout = 0xFFFF;



	if (sypcr & SYPCR_SWP)

		wdt_timeout *= 2048;



	m8xx_has_internal_rtc = in_be16(&imap->im_sit.sit_rtcsc) & RTCSC_RTE;



	/* if the internal RTC is off use a kernel timer */

	if (!m8xx_has_internal_rtc) {

		if (wdt_timeout < (binfo->bi_intfreq/HZ))

			printk(KERN_ERR "m8xx_wdt: timeout too short for ktimer!\n");

		m8xx_wdt_install_timer();

	} else

		m8xx_wdt_install_irq(imap, binfo);



	wdt_timeout /= binfo->bi_intfreq;

}

arch/ppc/syslib/m8xx_wdt.h

+4 −0
Original line number Diff line number Diff line
@@ -9,8 +9,12 @@ 
#ifndef _PPC_SYSLIB_M8XX_WDT_H

#define _PPC_SYSLIB_M8XX_WDT_H



extern int m8xx_has_internal_rtc;



extern void m8xx_wdt_handler_install(bd_t * binfo);

extern int m8xx_wdt_get_timeout(void);

extern void m8xx_wdt_reset(void);

extern void m8xx_wdt_install_timer(void);

extern void m8xx_wdt_stop_timer(void);



#endif				/* _PPC_SYSLIB_M8XX_WDT_H */

drivers/char/watchdog/mpc8xx_wdt.c

+8 −5
Original line number Diff line number Diff line
@@ -27,7 +27,10 @@ static void mpc8xx_wdt_handler_disable(void) 
{

	volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;



	imap->im_sit.sit_piscr &= ~(PISCR_PIE | PISCR_PTE);

	if (!m8xx_has_internal_rtc)

		m8xx_wdt_stop_timer();

	else

		out_be32(imap->im_sit.sit_piscr, in_be32(&imap->im_sit.sit_piscr) & ~(PISCR_PIE | PISCR_PTE));



	printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler deactivated\n");

}
@@ -36,7 +39,10 @@ static void mpc8xx_wdt_handler_enable(void) 
{

	volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;



	imap->im_sit.sit_piscr |= PISCR_PIE | PISCR_PTE;

	if (!m8xx_has_internal_rtc)

		m8xx_wdt_install_timer();

	else

		out_be32(&imap->im_sit.sit_piscr, in_be32(&imap->im_sit.sit_piscr) | PISCR_PIE | PISCR_PTE);



	printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler activated\n");

}
@@ -68,9 +74,6 @@ static int mpc8xx_wdt_release(struct inode *inode, struct file *file) 
static ssize_t mpc8xx_wdt_write(struct file *file, const char *data, size_t len,

				loff_t * ppos)

{

	if (ppos != &file->f_pos)

		return -ESPIPE;



	if (len)

		m8xx_wdt_reset();

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