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Diffstat (limited to 'arch/mips/kernel/time.c')
-rw-r--r-- | arch/mips/kernel/time.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c new file mode 100644 index 00000000..99d73b72 --- /dev/null +++ b/arch/mips/kernel/time.c @@ -0,0 +1,126 @@ +/* + * 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/div64.h> +#include <asm/smtc_ipi.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(); + + if (!mips_clockevent_init() || !cpu_has_mfc0_count_bug()) + init_mips_clocksource(); +} |