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Diffstat (limited to 'arch/sh/kernel/time_64.c')
-rw-r--r-- | arch/sh/kernel/time_64.c | 528 |
1 files changed, 528 insertions, 0 deletions
diff --git a/arch/sh/kernel/time_64.c b/arch/sh/kernel/time_64.c new file mode 100644 index 0000000..4c52fee --- /dev/null +++ b/arch/sh/kernel/time_64.c @@ -0,0 +1,528 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * arch/sh64/kernel/time.c + * + * Copyright (C) 2000, 2001 Paolo Alberelli + * Copyright (C) 2003 - 2007 Paul Mundt + * Copyright (C) 2003 Richard Curnow + * + * Original TMU/RTC code taken from sh version. + * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka + * Some code taken from i386 version. + * Copyright (C) 1991, 1992, 1995 Linus Torvalds + */ +#include <linux/errno.h> +#include <linux/rwsem.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/param.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/time.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/profile.h> +#include <linux/smp.h> +#include <linux/module.h> +#include <linux/bcd.h> +#include <linux/timex.h> +#include <linux/irq.h> +#include <linux/io.h> +#include <linux/platform_device.h> +#include <asm/cpu/registers.h> /* required by inline __asm__ stmt. */ +#include <asm/cpu/irq.h> +#include <asm/addrspace.h> +#include <asm/processor.h> +#include <asm/uaccess.h> +#include <asm/delay.h> + +#define TMU_TOCR_INIT 0x00 +#define TMU0_TCR_INIT 0x0020 +#define TMU_TSTR_INIT 1 +#define TMU_TSTR_OFF 0 + +/* Real Time Clock */ +#define RTC_BLOCK_OFF 0x01040000 +#define RTC_BASE PHYS_PERIPHERAL_BLOCK + RTC_BLOCK_OFF +#define RTC_RCR1_CIE 0x10 /* Carry Interrupt Enable */ +#define RTC_RCR1 (rtc_base + 0x38) + +/* Clock, Power and Reset Controller */ +#define CPRC_BLOCK_OFF 0x01010000 +#define CPRC_BASE PHYS_PERIPHERAL_BLOCK + CPRC_BLOCK_OFF + +#define FRQCR (cprc_base+0x0) +#define WTCSR (cprc_base+0x0018) +#define STBCR (cprc_base+0x0030) + +/* Time Management Unit */ +#define TMU_BLOCK_OFF 0x01020000 +#define TMU_BASE PHYS_PERIPHERAL_BLOCK + TMU_BLOCK_OFF +#define TMU0_BASE tmu_base + 0x8 + (0xc * 0x0) +#define TMU1_BASE tmu_base + 0x8 + (0xc * 0x1) +#define TMU2_BASE tmu_base + 0x8 + (0xc * 0x2) + +#define TMU_TOCR tmu_base+0x0 /* Byte access */ +#define TMU_TSTR tmu_base+0x4 /* Byte access */ + +#define TMU0_TCOR TMU0_BASE+0x0 /* Long access */ +#define TMU0_TCNT TMU0_BASE+0x4 /* Long access */ +#define TMU0_TCR TMU0_BASE+0x8 /* Word access */ + +#define TICK_SIZE (tick_nsec / 1000) + +static unsigned long tmu_base, rtc_base; +unsigned long cprc_base; + +/* Variables to allow interpolation of time of day to resolution better than a + * jiffy. */ + +/* This is effectively protected by xtime_lock */ +static unsigned long ctc_last_interrupt; +static unsigned long long usecs_per_jiffy = 1000000/HZ; /* Approximation */ + +#define CTC_JIFFY_SCALE_SHIFT 40 + +/* 2**CTC_JIFFY_SCALE_SHIFT / ctc_ticks_per_jiffy */ +static unsigned long long scaled_recip_ctc_ticks_per_jiffy; + +/* Estimate number of microseconds that have elapsed since the last timer tick, + by scaling the delta that has occurred in the CTC register. + + WARNING WARNING WARNING : This algorithm relies on the CTC decrementing at + the CPU clock rate. If the CPU sleeps, the CTC stops counting. Bear this + in mind if enabling SLEEP_WORKS in process.c. In that case, this algorithm + probably needs to use TMU.TCNT0 instead. This will work even if the CPU is + sleeping, though will be coarser. + + FIXME : What if usecs_per_tick is moving around too much, e.g. if an adjtime + is running or if the freq or tick arguments of adjtimex are modified after + we have calibrated the scaling factor? This will result in either a jump at + the end of a tick period, or a wrap backwards at the start of the next one, + if the application is reading the time of day often enough. I think we + ought to do better than this. For this reason, usecs_per_jiffy is left + separated out in the calculation below. This allows some future hook into + the adjtime-related stuff in kernel/timer.c to remove this hazard. + +*/ + +static unsigned long usecs_since_tick(void) +{ + unsigned long long current_ctc; + long ctc_ticks_since_interrupt; + unsigned long long ull_ctc_ticks_since_interrupt; + unsigned long result; + + unsigned long long mul1_out; + unsigned long long mul1_out_high; + unsigned long long mul2_out_low, mul2_out_high; + + /* Read CTC register */ + asm ("getcon cr62, %0" : "=r" (current_ctc)); + /* Note, the CTC counts down on each CPU clock, not up. + Note(2), use long type to get correct wraparound arithmetic when + the counter crosses zero. */ + ctc_ticks_since_interrupt = (long) ctc_last_interrupt - (long) current_ctc; + ull_ctc_ticks_since_interrupt = (unsigned long long) ctc_ticks_since_interrupt; + + /* Inline assembly to do 32x32x32->64 multiplier */ + asm volatile ("mulu.l %1, %2, %0" : + "=r" (mul1_out) : + "r" (ull_ctc_ticks_since_interrupt), "r" (usecs_per_jiffy)); + + mul1_out_high = mul1_out >> 32; + + asm volatile ("mulu.l %1, %2, %0" : + "=r" (mul2_out_low) : + "r" (mul1_out), "r" (scaled_recip_ctc_ticks_per_jiffy)); + +#if 1 + asm volatile ("mulu.l %1, %2, %0" : + "=r" (mul2_out_high) : + "r" (mul1_out_high), "r" (scaled_recip_ctc_ticks_per_jiffy)); +#endif + + result = (unsigned long) (((mul2_out_high << 32) + mul2_out_low) >> CTC_JIFFY_SCALE_SHIFT); + + return result; +} + +void do_gettimeofday(struct timeval *tv) +{ + unsigned long flags; + unsigned long seq; + unsigned long usec, sec; + + do { + seq = read_seqbegin_irqsave(&xtime_lock, flags); + usec = usecs_since_tick(); + sec = xtime.tv_sec; + usec += xtime.tv_nsec / 1000; + } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); + + while (usec >= 1000000) { + usec -= 1000000; + sec++; + } + + tv->tv_sec = sec; + tv->tv_usec = usec; +} + +int do_settimeofday(struct timespec *tv) +{ + time_t wtm_sec, sec = tv->tv_sec; + long wtm_nsec, nsec = tv->tv_nsec; + + if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) + return -EINVAL; + + write_seqlock_irq(&xtime_lock); + /* + * This is revolting. We need to set "xtime" correctly. However, the + * value in this location is the value at the most recent update of + * wall time. Discover what correction gettimeofday() would have + * made, and then undo it! + */ + nsec -= 1000 * usecs_since_tick(); + + wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); + wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); + + set_normalized_timespec(&xtime, sec, nsec); + set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); + + ntp_clear(); + write_sequnlock_irq(&xtime_lock); + clock_was_set(); + + return 0; +} +EXPORT_SYMBOL(do_settimeofday); + +/* Dummy RTC ops */ +static void null_rtc_get_time(struct timespec *tv) +{ + tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0); + tv->tv_nsec = 0; +} + +static int null_rtc_set_time(const time_t secs) +{ + return 0; +} + +void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time; +int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time; + +/* last time the RTC clock got updated */ +static long last_rtc_update; + +/* + * timer_interrupt() needs to keep up the real-time clock, + * as well as call the "do_timer()" routine every clocktick + */ +static inline void do_timer_interrupt(void) +{ + unsigned long long current_ctc; + asm ("getcon cr62, %0" : "=r" (current_ctc)); + ctc_last_interrupt = (unsigned long) current_ctc; + + do_timer(1); +#ifndef CONFIG_SMP + update_process_times(user_mode(get_irq_regs())); +#endif + if (current->pid) + profile_tick(CPU_PROFILING); + +#ifdef CONFIG_HEARTBEAT + if (sh_mv.mv_heartbeat != NULL) + sh_mv.mv_heartbeat(); +#endif + + /* + * If we have an externally synchronized Linux clock, then update + * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be + * called as close as possible to 500 ms before the new second starts. + */ + if (ntp_synced() && + xtime.tv_sec > last_rtc_update + 660 && + (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && + (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) { + if (rtc_sh_set_time(xtime.tv_sec) == 0) + last_rtc_update = xtime.tv_sec; + else + /* do it again in 60 s */ + last_rtc_update = xtime.tv_sec - 600; + } +} + +/* + * This is the same as the above, except we _also_ save the current + * Time Stamp Counter value at the time of the timer interrupt, so that + * we later on can estimate the time of day more exactly. + */ +static irqreturn_t timer_interrupt(int irq, void *dev_id) +{ + unsigned long timer_status; + + /* Clear UNF bit */ + timer_status = ctrl_inw(TMU0_TCR); + timer_status &= ~0x100; + ctrl_outw(timer_status, TMU0_TCR); + + /* + * Here we are in the timer irq handler. We just have irqs locally + * disabled but we don't know if the timer_bh is running on the other + * CPU. We need to avoid to SMP race with it. NOTE: we don' t need + * the irq version of write_lock because as just said we have irq + * locally disabled. -arca + */ + write_lock(&xtime_lock); + do_timer_interrupt(); + write_unlock(&xtime_lock); + + return IRQ_HANDLED; +} + + +static __init unsigned int get_cpu_hz(void) +{ + unsigned int count; + unsigned long __dummy; + unsigned long ctc_val_init, ctc_val; + + /* + ** Regardless the toolchain, force the compiler to use the + ** arbitrary register r3 as a clock tick counter. + ** NOTE: r3 must be in accordance with sh64_rtc_interrupt() + */ + register unsigned long long __rtc_irq_flag __asm__ ("r3"); + + local_irq_enable(); + do {} while (ctrl_inb(rtc_base) != 0); + ctrl_outb(RTC_RCR1_CIE, RTC_RCR1); /* Enable carry interrupt */ + + /* + * r3 is arbitrary. CDC does not support "=z". + */ + ctc_val_init = 0xffffffff; + ctc_val = ctc_val_init; + + asm volatile("gettr tr0, %1\n\t" + "putcon %0, " __CTC "\n\t" + "and %2, r63, %2\n\t" + "pta $+4, tr0\n\t" + "beq/l %2, r63, tr0\n\t" + "ptabs %1, tr0\n\t" + "getcon " __CTC ", %0\n\t" + : "=r"(ctc_val), "=r" (__dummy), "=r" (__rtc_irq_flag) + : "0" (0)); + local_irq_disable(); + /* + * SH-3: + * CPU clock = 4 stages * loop + * tst rm,rm if id ex + * bt/s 1b if id ex + * add #1,rd if id ex + * (if) pipe line stole + * tst rm,rm if id ex + * .... + * + * + * SH-4: + * CPU clock = 6 stages * loop + * I don't know why. + * .... + * + * SH-5: + * Use CTC register to count. This approach returns the right value + * even if the I-cache is disabled (e.g. whilst debugging.) + * + */ + + count = ctc_val_init - ctc_val; /* CTC counts down */ + +#if defined (CONFIG_SH_SIMULATOR) + /* + * Let's pretend we are a 5MHz SH-5 to avoid a too + * little timer interval. Also to keep delay + * calibration within a reasonable time. + */ + return 5000000; +#else + /* + * This really is count by the number of clock cycles + * by the ratio between a complete R64CNT + * wrap-around (128) and CUI interrupt being raised (64). + */ + return count*2; +#endif +} + +static irqreturn_t sh64_rtc_interrupt(int irq, void *dev_id) +{ + struct pt_regs *regs = get_irq_regs(); + + ctrl_outb(0, RTC_RCR1); /* Disable Carry Interrupts */ + regs->regs[3] = 1; /* Using r3 */ + + return IRQ_HANDLED; +} + +static struct irqaction irq0 = { + .handler = timer_interrupt, + .flags = IRQF_DISABLED, + .mask = CPU_MASK_NONE, + .name = "timer", +}; +static struct irqaction irq1 = { + .handler = sh64_rtc_interrupt, + .flags = IRQF_DISABLED, + .mask = CPU_MASK_NONE, + .name = "rtc", +}; + +void __init time_init(void) +{ + unsigned int cpu_clock, master_clock, bus_clock, module_clock; + unsigned long interval; + unsigned long frqcr, ifc, pfc; + static int ifc_table[] = { 2, 4, 6, 8, 10, 12, 16, 24 }; +#define bfc_table ifc_table /* Same */ +#define pfc_table ifc_table /* Same */ + + tmu_base = onchip_remap(TMU_BASE, 1024, "TMU"); + if (!tmu_base) { + panic("Unable to remap TMU\n"); + } + + rtc_base = onchip_remap(RTC_BASE, 1024, "RTC"); + if (!rtc_base) { + panic("Unable to remap RTC\n"); + } + + cprc_base = onchip_remap(CPRC_BASE, 1024, "CPRC"); + if (!cprc_base) { + panic("Unable to remap CPRC\n"); + } + + rtc_sh_get_time(&xtime); + + setup_irq(TIMER_IRQ, &irq0); + setup_irq(RTC_IRQ, &irq1); + + /* Check how fast it is.. */ + cpu_clock = get_cpu_hz(); + + /* Note careful order of operations to maintain reasonable precision and avoid overflow. */ + scaled_recip_ctc_ticks_per_jiffy = ((1ULL << CTC_JIFFY_SCALE_SHIFT) / (unsigned long long)(cpu_clock / HZ)); + + free_irq(RTC_IRQ, NULL); + + printk("CPU clock: %d.%02dMHz\n", + (cpu_clock / 1000000), (cpu_clock % 1000000)/10000); + { + unsigned short bfc; + frqcr = ctrl_inl(FRQCR); + ifc = ifc_table[(frqcr>> 6) & 0x0007]; + bfc = bfc_table[(frqcr>> 3) & 0x0007]; + pfc = pfc_table[(frqcr>> 12) & 0x0007]; + master_clock = cpu_clock * ifc; + bus_clock = master_clock/bfc; + } + + printk("Bus clock: %d.%02dMHz\n", + (bus_clock/1000000), (bus_clock % 1000000)/10000); + module_clock = master_clock/pfc; + printk("Module clock: %d.%02dMHz\n", + (module_clock/1000000), (module_clock % 1000000)/10000); + interval = (module_clock/(HZ*4)); + + printk("Interval = %ld\n", interval); + + current_cpu_data.cpu_clock = cpu_clock; + current_cpu_data.master_clock = master_clock; + current_cpu_data.bus_clock = bus_clock; + current_cpu_data.module_clock = module_clock; + + /* Start TMU0 */ + ctrl_outb(TMU_TSTR_OFF, TMU_TSTR); + ctrl_outb(TMU_TOCR_INIT, TMU_TOCR); + ctrl_outw(TMU0_TCR_INIT, TMU0_TCR); + ctrl_outl(interval, TMU0_TCOR); + ctrl_outl(interval, TMU0_TCNT); + ctrl_outb(TMU_TSTR_INIT, TMU_TSTR); +} + +void enter_deep_standby(void) +{ + /* Disable watchdog timer */ + ctrl_outl(0xa5000000, WTCSR); + /* Configure deep standby on sleep */ + ctrl_outl(0x03, STBCR); + +#ifdef CONFIG_SH_ALPHANUMERIC + { + extern void mach_alphanum(int position, unsigned char value); + extern void mach_alphanum_brightness(int setting); + char halted[] = "Halted. "; + int i; + mach_alphanum_brightness(6); /* dimmest setting above off */ + for (i=0; i<8; i++) { + mach_alphanum(i, halted[i]); + } + asm __volatile__ ("synco"); + } +#endif + + asm __volatile__ ("sleep"); + asm __volatile__ ("synci"); + asm __volatile__ ("nop"); + asm __volatile__ ("nop"); + asm __volatile__ ("nop"); + asm __volatile__ ("nop"); + panic("Unexpected wakeup!\n"); +} + +static struct resource rtc_resources[] = { + [0] = { + /* RTC base, filled in by rtc_init */ + .flags = IORESOURCE_IO, + }, + [1] = { + /* Period IRQ */ + .start = IRQ_PRI, + .flags = IORESOURCE_IRQ, + }, + [2] = { + /* Carry IRQ */ + .start = IRQ_CUI, + .flags = IORESOURCE_IRQ, + }, + [3] = { + /* Alarm IRQ */ + .start = IRQ_ATI, + .flags = IORESOURCE_IRQ, + }, +}; + +static struct platform_device rtc_device = { + .name = "sh-rtc", + .id = -1, + .num_resources = ARRAY_SIZE(rtc_resources), + .resource = rtc_resources, +}; + +static int __init rtc_init(void) +{ + rtc_resources[0].start = rtc_base; + rtc_resources[0].end = rtc_resources[0].start + 0x58 - 1; + + return platform_device_register(&rtc_device); +} +device_initcall(rtc_init); |