b633648c5a
Nobody is maintaining SMTC anymore and there also seems to be no userbase. Which is a pity - the SMTC technology primarily developed by Kevin D. Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT ASE's power and elegance. Based on Markos Chandras <Markos.Chandras@imgtec.com> patch https://patchwork.linux-mips.org/patch/6719/ which while very similar did no longer apply cleanly when I tried to merge it plus some additional post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to merge once upon a time. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
134 lines
3.3 KiB
C
134 lines
3.3 KiB
C
/*
|
|
* Copyright 2001 MontaVista Software Inc.
|
|
* Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
|
|
* Copyright (c) 2003, 2004 Maciej W. Rozycki
|
|
*
|
|
* Common time service routines for MIPS machines.
|
|
*
|
|
* 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.
|
|
*/
|
|
#include <linux/bug.h>
|
|
#include <linux/clockchips.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/param.h>
|
|
#include <linux/time.h>
|
|
#include <linux/timex.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/export.h>
|
|
|
|
#include <asm/cpu-features.h>
|
|
#include <asm/cpu-type.h>
|
|
#include <asm/div64.h>
|
|
#include <asm/time.h>
|
|
|
|
/*
|
|
* forward reference
|
|
*/
|
|
DEFINE_SPINLOCK(rtc_lock);
|
|
EXPORT_SYMBOL(rtc_lock);
|
|
|
|
int __weak rtc_mips_set_time(unsigned long sec)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int __weak rtc_mips_set_mmss(unsigned long nowtime)
|
|
{
|
|
return rtc_mips_set_time(nowtime);
|
|
}
|
|
|
|
int update_persistent_clock(struct timespec now)
|
|
{
|
|
return rtc_mips_set_mmss(now.tv_sec);
|
|
}
|
|
|
|
static int null_perf_irq(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int (*perf_irq)(void) = null_perf_irq;
|
|
|
|
EXPORT_SYMBOL(perf_irq);
|
|
|
|
/*
|
|
* time_init() - it does the following things.
|
|
*
|
|
* 1) plat_time_init() -
|
|
* a) (optional) set up RTC routines,
|
|
* b) (optional) calibrate and set the mips_hpt_frequency
|
|
* (only needed if you intended to use cpu counter as timer interrupt
|
|
* source)
|
|
* 2) calculate a couple of cached variables for later usage
|
|
*/
|
|
|
|
unsigned int mips_hpt_frequency;
|
|
|
|
/*
|
|
* This function exists in order to cause an error due to a duplicate
|
|
* definition if platform code should have its own implementation. The hook
|
|
* to use instead is plat_time_init. plat_time_init does not receive the
|
|
* irqaction pointer argument anymore. This is because any function which
|
|
* initializes an interrupt timer now takes care of its own request_irq rsp.
|
|
* setup_irq calls and each clock_event_device should use its own
|
|
* struct irqrequest.
|
|
*/
|
|
void __init plat_timer_setup(void)
|
|
{
|
|
BUG();
|
|
}
|
|
|
|
static __init int cpu_has_mfc0_count_bug(void)
|
|
{
|
|
switch (current_cpu_type()) {
|
|
case CPU_R4000PC:
|
|
case CPU_R4000SC:
|
|
case CPU_R4000MC:
|
|
/*
|
|
* V3.0 is documented as suffering from the mfc0 from count bug.
|
|
* Afaik this is the last version of the R4000. Later versions
|
|
* were marketed as R4400.
|
|
*/
|
|
return 1;
|
|
|
|
case CPU_R4400PC:
|
|
case CPU_R4400SC:
|
|
case CPU_R4400MC:
|
|
/*
|
|
* The published errata for the R4400 up to 3.0 say the CPU
|
|
* has the mfc0 from count bug.
|
|
*/
|
|
if ((current_cpu_data.processor_id & 0xff) <= 0x30)
|
|
return 1;
|
|
|
|
/*
|
|
* we assume newer revisions are ok
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void __init time_init(void)
|
|
{
|
|
plat_time_init();
|
|
|
|
/*
|
|
* The use of the R4k timer as a clock event takes precedence;
|
|
* if reading the Count register might interfere with the timer
|
|
* interrupt, then we don't use the timer as a clock source.
|
|
* We may still use the timer as a clock source though if the
|
|
* timer interrupt isn't reliable; the interference doesn't
|
|
* matter then, because we don't use the interrupt.
|
|
*/
|
|
if (mips_clockevent_init() != 0 || !cpu_has_mfc0_count_bug())
|
|
init_mips_clocksource();
|
|
}
|