7b1f62076b
Currently, whenever CONFIG_ARCH_USES_GETTIMEOFFSET is enabled, each arch core provides a single implementation of arch_gettimeoffset(). In many cases, different sub-architectures, different machines, or different timer providers exist, and so the arch ends up implementing arch_gettimeoffset() as a call-through-pointer anyway. Examples are ARM, Cris, M68K, and it's arguable that the remaining architectures, M32R and Blackfin, should be doing this anyway. Modify arch_gettimeoffset so that it itself is a function pointer, which the arch initializes. This will allow later changes to move the initialization of this function into individual machine support or timer drivers. This is particularly useful for code in drivers/clocksource which should rely on an arch-independant mechanism to register their implementation of arch_gettimeoffset(). This patch also converts the Cris architecture to set arch_gettimeoffset directly to the final implementation in time_init(), because Cris already had separate time_init() functions per sub-architecture. M68K and ARM are converted to set arch_gettimeoffset to the final implementation in later patches, because they already have function pointers in place for this purpose. Cc: Russell King <linux@arm.linux.org.uk> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Stephen Warren <swarren@nvidia.com>
199 lines
4.9 KiB
C
199 lines
4.9 KiB
C
/*
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* linux/arch/m32r/kernel/time.c
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*
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* Copyright (c) 2001, 2002 Hiroyuki Kondo, Hirokazu Takata,
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* Hitoshi Yamamoto
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* Taken from i386 version.
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* Copyright (C) 1991, 1992, 1995 Linus Torvalds
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* Copyright (C) 1996, 1997, 1998 Ralf Baechle
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*
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* This file contains the time handling details for PC-style clocks as
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* found in some MIPS systems.
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*
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* Some code taken from sh version.
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* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
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* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
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*/
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#undef DEBUG_TIMER
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/param.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/profile.h>
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#include <asm/io.h>
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#include <asm/m32r.h>
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#include <asm/hw_irq.h>
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#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
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/* this needs a better home */
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DEFINE_SPINLOCK(rtc_lock);
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#ifdef CONFIG_RTC_DRV_CMOS_MODULE
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EXPORT_SYMBOL(rtc_lock);
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#endif
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#endif /* pc-style 'CMOS' RTC support */
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#ifdef CONFIG_SMP
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extern void smp_local_timer_interrupt(void);
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#endif
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#define TICK_SIZE (tick_nsec / 1000)
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/*
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* Change this if you have some constant time drift
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*/
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/* This is for machines which generate the exact clock. */
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#define USECS_PER_JIFFY (1000000/HZ)
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static unsigned long latch;
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static u32 m32r_gettimeoffset(void)
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{
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unsigned long elapsed_time = 0; /* [us] */
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#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
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|| defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
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|| defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104)
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#ifndef CONFIG_SMP
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unsigned long count;
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/* timer count may underflow right here */
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count = inl(M32R_MFT2CUT_PORTL);
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if (inl(M32R_ICU_CR18_PORTL) & 0x00000100) /* underflow check */
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count = 0;
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count = (latch - count) * TICK_SIZE;
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elapsed_time = DIV_ROUND_CLOSEST(count, latch);
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/* NOTE: LATCH is equal to the "interval" value (= reload count). */
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#else /* CONFIG_SMP */
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unsigned long count;
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static unsigned long p_jiffies = -1;
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static unsigned long p_count = 0;
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/* timer count may underflow right here */
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count = inl(M32R_MFT2CUT_PORTL);
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if (jiffies == p_jiffies && count > p_count)
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count = 0;
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p_jiffies = jiffies;
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p_count = count;
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count = (latch - count) * TICK_SIZE;
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elapsed_time = DIV_ROUND_CLOSEST(count, latch);
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/* NOTE: LATCH is equal to the "interval" value (= reload count). */
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#endif /* CONFIG_SMP */
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#elif defined(CONFIG_CHIP_M32310)
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#warning do_gettimeoffse not implemented
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#else
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#error no chip configuration
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#endif
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return elapsed_time * 1000;
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}
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/*
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* timer_interrupt() needs to keep up the real-time clock,
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* as well as call the "xtime_update()" routine every clocktick
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*/
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static irqreturn_t timer_interrupt(int irq, void *dev_id)
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{
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#ifndef CONFIG_SMP
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profile_tick(CPU_PROFILING);
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#endif
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xtime_update(1);
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#ifndef CONFIG_SMP
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update_process_times(user_mode(get_irq_regs()));
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#endif
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/* As we return to user mode fire off the other CPU schedulers..
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this is basically because we don't yet share IRQ's around.
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This message is rigged to be safe on the 386 - basically it's
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a hack, so don't look closely for now.. */
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#ifdef CONFIG_SMP
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smp_local_timer_interrupt();
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smp_send_timer();
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#endif
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return IRQ_HANDLED;
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}
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static struct irqaction irq0 = {
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.handler = timer_interrupt,
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.flags = IRQF_DISABLED,
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.name = "MFT2",
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};
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void read_persistent_clock(struct timespec *ts)
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{
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unsigned int epoch, year, mon, day, hour, min, sec;
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sec = min = hour = day = mon = year = 0;
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epoch = 0;
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year = 23;
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mon = 4;
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day = 17;
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/* Attempt to guess the epoch. This is the same heuristic as in rtc.c
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so no stupid things will happen to timekeeping. Who knows, maybe
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Ultrix also uses 1952 as epoch ... */
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if (year > 10 && year < 44)
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epoch = 1980;
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else if (year < 96)
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epoch = 1952;
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year += epoch;
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ts->tv_sec = mktime(year, mon, day, hour, min, sec);
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ts->tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
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}
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void __init time_init(void)
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{
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arch_gettimeoffset = m32r_gettimeoffset;
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#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
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|| defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
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|| defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104)
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/* M32102 MFT setup */
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setup_irq(M32R_IRQ_MFT2, &irq0);
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{
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unsigned long bus_clock;
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unsigned short divide;
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bus_clock = boot_cpu_data.bus_clock;
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divide = boot_cpu_data.timer_divide;
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latch = DIV_ROUND_CLOSEST(bus_clock/divide, HZ);
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printk("Timer start : latch = %ld\n", latch);
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outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \
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|M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL);
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outl(latch, M32R_MFT2RLD_PORTL);
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outl(latch, M32R_MFT2CUT_PORTL);
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outl(0, M32R_MFT2CMPRLD_PORTL);
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outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL);
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}
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#elif defined(CONFIG_CHIP_M32310)
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#warning time_init not implemented
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#else
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#error no chip configuration
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#endif
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}
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