linux/arch/mips/kernel/time.c
Paul Burton 7d630e83fc MIPS: Remove plat_timer_setup()
The plat_timer_setup() function is entirely unused - nothing calls it,
and no platforms provide it. Perhaps our dummy implementation was once
useful as an aid in forward porting platforms, but its time has long
since passed so let's remove the dead code.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17175/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-29 15:21:55 +02:00

122 lines
2.8 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 -ENODEV;
}
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;
EXPORT_SYMBOL_GPL(mips_hpt_frequency);
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();
}