Commit fbdb5f86 authored by Jesper Nilsson's avatar Jesper Nilsson
Browse files

CRIS v32: Update and improve kernel/time.c 

- Shorten include paths to machine dependent header files.
- Register name for first timer is now regi_timer0.
- Remove raw_printk hack, use oops_in_progress instead.
- Add handling of CPU frequency scaling for CRIS.
- Remove regs parameter to timer_interrupt, get them from get_irq_regs instead.
- Whitespace and formatting changes.
parent bd1c8c54

arch/cris/arch-v32/kernel/time.c

+139 −98
Original line number Diff line number Diff line 
/* $Id: time.c,v 1.19 2005/04/29 05:40:09 starvik Exp $

 *

/*

 *  linux/arch/cris/arch-v32/kernel/time.c

 *

 *  Copyright (C) 2003 Axis Communications AB

 *  Copyright (C) 2003-2007 Axis Communications AB

 *

 */
@@ -14,26 +13,32 @@ 
#include <linux/sched.h>

#include <linux/init.h>

#include <linux/threads.h>

#include <linux/cpufreq.h>

#include <asm/types.h>

#include <asm/signal.h>

#include <asm/io.h>

#include <asm/delay.h>

#include <asm/rtc.h>

#include <asm/irq.h>



#include <asm/arch/hwregs/reg_map.h>

#include <asm/arch/hwregs/reg_rdwr.h>

#include <asm/arch/hwregs/timer_defs.h>

#include <asm/arch/hwregs/intr_vect_defs.h>

#include <asm/irq_regs.h>



#include <hwregs/reg_map.h>

#include <hwregs/reg_rdwr.h>

#include <hwregs/timer_defs.h>

#include <hwregs/intr_vect_defs.h>

#ifdef CONFIG_CRIS_MACH_ARTPEC3

#include <hwregs/clkgen_defs.h>

#endif



/* Watchdog defines */

#define ETRAX_WD_KEY_MASK	0x7F /* key is 7 bit */

#define ETRAX_WD_HZ		763 /* watchdog counts at 763 Hz */

#define ETRAX_WD_CNT      ((2*ETRAX_WD_HZ)/HZ + 1) /* Number of 763 counts before watchdog bites */

/* Number of 763 counts before watchdog bites */

#define ETRAX_WD_CNT		((2*ETRAX_WD_HZ)/HZ + 1)



unsigned long timer_regs[NR_CPUS] =

{

  regi_timer,

	regi_timer0,

#ifdef CONFIG_SMP

	regi_timer2

#endif
@@ -44,12 +49,22 @@ extern int set_rtc_mmss(unsigned long nowtime); 
extern int setup_irq(int, struct irqaction *);

extern int have_rtc;



#ifdef CONFIG_CPU_FREQ

static int

cris_time_freq_notifier(struct notifier_block *nb, unsigned long val,

			void *data);



static struct notifier_block cris_time_freq_notifier_block = {

	.notifier_call = cris_time_freq_notifier,

};

#endif



unsigned long get_ns_in_jiffie(void)

{

	reg_timer_r_tmr0_data data;

	unsigned long ns;



	data = REG_RD(timer, regi_timer, r_tmr0_data);

	data = REG_RD(timer, regi_timer0, r_tmr0_data);

	ns = (TIMER0_DIV - data) * 10;

	return ns;

}
@@ -59,31 +74,27 @@ unsigned long do_slow_gettimeoffset(void) 
	unsigned long count;

	unsigned long usec_count = 0;



	static unsigned long count_p = TIMER0_DIV;/* for the first call after boot */

	/* For the first call after boot */

	static unsigned long count_p = TIMER0_DIV;

	static unsigned long jiffies_p = 0;



	/*

	 * cache volatile jiffies temporarily; we have IRQs turned off.

	 */

	/* Cache volatile jiffies temporarily; we have IRQs turned off. */

	unsigned long jiffies_t;



	/* The timer interrupt comes from Etrax timer 0. In order to get

	 * better precision, we check the current value. It might have

	 * underflowed already though.

	 */



	count = REG_RD(timer, regi_timer, r_tmr0_data);

	 * underflowed already though. */

	count = REG_RD(timer, regi_timer0, r_tmr0_data);

	jiffies_t = jiffies;



	/*

	 * avoiding timer inconsistencies (they are rare, but they happen)...

	 * there are one problem that must be avoided here:

	/* Avoiding timer inconsistencies (they are rare, but they happen)

	 * There is one problem that must be avoided here:

	 *	1. the timer counter underflows

	 */

	if( jiffies_t == jiffies_p ) {

		if( count > count_p ) {

			/* Timer wrapped, use new count and prescale

			 * increase the time corresponding to one jiffie

			/* Timer wrapped, use new count and prescale.

			 * Increase the time corresponding to one jiffy.

			 */

			usec_count = 1000000/HZ;

		}
@@ -106,17 +117,15 @@ unsigned long do_slow_gettimeoffset(void) 
 */

/* This gives us 1.3 ms to do something useful when the NMI comes */



/* right now, starting the watchdog is the same as resetting it */

/* Right now, starting the watchdog is the same as resetting it */

#define start_watchdog reset_watchdog



#if defined(CONFIG_ETRAX_WATCHDOG)

static short int watchdog_key = 42;  /* arbitrary 7 bit number */

#endif



/* number of pages to consider "out of memory". it is normal that the memory

 * is used though, so put this really low.

 */



/* Number of pages to consider "out of memory". It is normal that the memory

 * is used though, so set this really low. */

#define WATCHDOG_MIN_FREE_PAGES 8



void
@@ -125,14 +134,15 @@ reset_watchdog(void) 
#if defined(CONFIG_ETRAX_WATCHDOG)

	reg_timer_rw_wd_ctrl wd_ctrl = { 0 };



	/* only keep watchdog happy as long as we have memory left! */

	/* Only keep watchdog happy as long as we have memory left! */

	if(nr_free_pages() > WATCHDOG_MIN_FREE_PAGES) {

		/* reset the watchdog with the inverse of the old key */

		watchdog_key ^= ETRAX_WD_KEY_MASK; /* invert key, which is 7 bits */

		/* Reset the watchdog with the inverse of the old key */

		/* Invert key, which is 7 bits */

		watchdog_key ^= ETRAX_WD_KEY_MASK;

		wd_ctrl.cnt = ETRAX_WD_CNT;

		wd_ctrl.cmd = regk_timer_start;

		wd_ctrl.key = watchdog_key;

		REG_WR(timer, regi_timer, rw_wd_ctrl, wd_ctrl);

		REG_WR(timer, regi_timer0, rw_wd_ctrl, wd_ctrl);

	}

#endif

}
@@ -148,7 +158,7 @@ stop_watchdog(void) 
	wd_ctrl.cnt = ETRAX_WD_CNT;

	wd_ctrl.cmd = regk_timer_stop;

	wd_ctrl.key = watchdog_key;

	REG_WR(timer, regi_timer, rw_wd_ctrl, wd_ctrl);

	REG_WR(timer, regi_timer0, rw_wd_ctrl, wd_ctrl);

#endif

}
@@ -160,17 +170,28 @@ handle_watchdog_bite(struct pt_regs* regs) 
#if defined(CONFIG_ETRAX_WATCHDOG)

	extern int cause_of_death;



	raw_printk("Watchdog bite\n");

	oops_in_progress = 1;

	printk(KERN_WARNING "Watchdog bite\n");



	/* Check if forced restart or unexpected watchdog */

	if (cause_of_death == 0xbedead) {

#ifdef CONFIG_CRIS_MACH_ARTPEC3

		/* There is a bug in Artpec-3 (voodoo TR 78) that requires

		 * us to go to lower frequency for the reset to be reliable

		 */

		reg_clkgen_rw_clk_ctrl ctrl =

			REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);

		ctrl.pll = 0;

		REG_WR(clkgen, regi_clkgen, rw_clk_ctrl, ctrl);

#endif

		while(1);

	}



	/* Unexpected watchdog, stop the watchdog and dump registers*/

	/* Unexpected watchdog, stop the watchdog and dump registers. */

	stop_watchdog();

	raw_printk("Oops: bitten by watchdog\n");

	printk(KERN_WARNING "Oops: bitten by watchdog\n");

	show_registers(regs);

	oops_in_progress = 0;

#ifndef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY

	reset_watchdog();

#endif
@@ -178,21 +199,19 @@ handle_watchdog_bite(struct pt_regs* regs) 
#endif

}



/* last time the cmos clock got updated */

/* Last time the cmos clock got updated. */

static long last_rtc_update = 0;



/*

 * timer_interrupt() needs to keep up the real-time clock,

 * as well as call the "do_timer()" routine every clocktick

 * as well as call the "do_timer()" routine every clocktick.

 */



//static unsigned short myjiff; /* used by our debug routine print_timestamp */



extern void cris_do_profile(struct pt_regs *regs);



static inline irqreturn_t

timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)

timer_interrupt(int irq, void *dev_id)

{

	struct pt_regs *regs = get_irq_regs();

	int cpu = smp_processor_id();

	reg_timer_r_masked_intr masked_intr;

	reg_timer_rw_ack_intr ack_intr = { 0 };
@@ -202,11 +221,11 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) 
	if (!masked_intr.tmr0)

		return IRQ_NONE;



	/* acknowledge the timer irq */

	/* Acknowledge the timer irq. */

	ack_intr.tmr0 = 1;

	REG_WR(timer, timer_regs[cpu], rw_ack_intr, ack_intr);



	/* reset watchdog otherwise it resets us! */

	/* Reset watchdog otherwise it resets us! */

	reset_watchdog();



        /* Update statistics. */
@@ -218,7 +237,7 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) 
	if (cpu != 0)

		return IRQ_HANDLED;



	/* call the real timer interrupt handler */

	/* Call the real timer interrupt handler */

	do_timer(1);



	/*
@@ -236,17 +255,17 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) 
		if (set_rtc_mmss(xtime.tv_sec) == 0)

			last_rtc_update = xtime.tv_sec;

		else

			last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */

			/* Do it again in 60 s */

			last_rtc_update = xtime.tv_sec - 600;

	}

        return IRQ_HANDLED;

}



/* timer is IRQF_SHARED so drivers can add stuff to the timer irq chain

 * it needs to be IRQF_DISABLED to make the jiffies update work properly

/* Timer is IRQF_SHARED so drivers can add stuff to the timer irq chain.

 * It needs to be IRQF_DISABLED to make the jiffies update work properly.

 */



static struct irqaction irq_timer = {

	.mask = timer_interrupt,

	.handler = timer_interrupt,

	.flags = IRQF_SHARED | IRQF_DISABLED,

	.mask = CPU_MASK_NONE,

	.name = "timer"
@@ -260,7 +279,7 @@ cris_timer_init(void) 
	reg_timer_rw_tmr0_div tmr0_div = TIMER0_DIV;

	reg_timer_rw_intr_mask timer_intr_mask;



	/* Setup the etrax timers

	/* Setup the etrax timers.

	 * Base frequency is 100MHz, divider 1000000 -> 100 HZ

	 * We use timer0, so timer1 is free.

	 * The trig timer is used by the fasttimer API if enabled.
@@ -273,7 +292,7 @@ cris_timer_init(void) 
	tmr0_ctrl.op = regk_timer_run;

	REG_WR(timer, timer_regs[cpu], rw_tmr0_ctrl, tmr0_ctrl); /* Start */



       	/* enable the timer irq */

	/* Enable the timer irq. */

	timer_intr_mask = REG_RD(timer, timer_regs[cpu], rw_intr_mask);

	timer_intr_mask.tmr0 = 1;

	REG_WR(timer, timer_regs[cpu], rw_intr_mask, timer_intr_mask);
@@ -284,7 +303,7 @@ time_init(void) 
{

	reg_intr_vect_rw_mask intr_mask;



	/* probe for the RTC and read it if it exists

	/* Probe for the RTC and read it if it exists.

	 * Before the RTC can be probed the loops_per_usec variable needs

	 * to be initialized to make usleep work. A better value for

	 * loops_per_usec is calculated by the kernel later once the
@@ -293,47 +312,45 @@ time_init(void) 
	loops_per_usec = 50;



	if(RTC_INIT() < 0) {

		/* no RTC, start at 1980 */

		/* No RTC, start at 1980 */

		xtime.tv_sec = 0;

		xtime.tv_nsec = 0;

		have_rtc = 0;

	} else {

		/* get the current time */

		/* Get the current time */

		have_rtc = 1;

		update_xtime_from_cmos();

	}



	/*

	 * Initialize wall_to_monotonic such that adding it to xtime will yield zero, the

	 * tv_nsec field must be normalized (i.e., 0 <= nsec < NSEC_PER_SEC).

	 * Initialize wall_to_monotonic such that adding it to

	 * xtime will yield zero, the tv_nsec field must be normalized

	 * (i.e., 0 <= nsec < NSEC_PER_SEC).

	 */

	set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec);



	/* Start CPU local timer */

	/* Start CPU local timer. */

	cris_timer_init();



	/* enable the timer irq in global config */

	intr_mask = REG_RD(intr_vect, regi_irq, rw_mask);

	intr_mask.timer = 1;

	REG_WR(intr_vect, regi_irq, rw_mask, intr_mask);



	/* now actually register the timer irq handler that calls timer_interrupt() */

	/* Enable the timer irq in global config. */

	intr_mask = REG_RD_VECT(intr_vect, regi_irq, rw_mask, 1);

	intr_mask.timer0 = 1;

	REG_WR_VECT(intr_vect, regi_irq, rw_mask, 1, intr_mask);



	setup_irq(TIMER_INTR_VECT, &irq_timer);

	/* Now actually register the timer irq handler that calls

	 * timer_interrupt(). */

	setup_irq(TIMER0_INTR_VECT, &irq_timer);



	/* enable watchdog if we should use one */

	/* Enable watchdog if we should use one. */



#if defined(CONFIG_ETRAX_WATCHDOG)

	printk("Enabling watchdog...\n");

	printk(KERN_INFO "Enabling watchdog...\n");

	start_watchdog();



	/* If we use the hardware watchdog, we want to trap it as an NMI

	   and dump registers before it resets us.  For this to happen, we

	   must set the "m" NMI enable flag (which once set, is unset only

	   when an NMI is taken).



	   The same goes for the external NMI, but that doesn't have any

	   driver or infrastructure support yet.  */

	 * and dump registers before it resets us.  For this to happen, we

	 * must set the "m" NMI enable flag (which once set, is unset only

	 * when an NMI is taken). */

	{

		unsigned long flags;

		local_save_flags(flags);
@@ -341,4 +358,28 @@ time_init(void) 
		local_irq_restore(flags);

	}

#endif



#ifdef CONFIG_CPU_FREQ

	cpufreq_register_notifier(&cris_time_freq_notifier_block,

		CPUFREQ_TRANSITION_NOTIFIER);

#endif

}



#ifdef CONFIG_CPU_FREQ

static int

cris_time_freq_notifier(struct notifier_block *nb, unsigned long val,

			void *data)

{

	struct cpufreq_freqs *freqs = data;

	if (val == CPUFREQ_POSTCHANGE) {

		reg_timer_r_tmr0_data data;

		reg_timer_rw_tmr0_div div = (freqs->new * 500) / HZ;

		do {

			data = REG_RD(timer, timer_regs[freqs->cpu],

				r_tmr0_data);

		} while (data > 20);

		REG_WR(timer, timer_regs[freqs->cpu], rw_tmr0_div, div);

	}

	return 0;

}

#endif

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