diff options
Diffstat (limited to 'arch/mips/sgi-ip27/ip27-timer.c')
| -rw-r--r-- | arch/mips/sgi-ip27/ip27-timer.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c new file mode 100644 index 00000000000..8c1b96fffa7 --- /dev/null +++ b/arch/mips/sgi-ip27/ip27-timer.c @@ -0,0 +1,243 @@ +/* + * Copytight (C) 1999, 2000, 05 Ralf Baechle (ralf@linux-mips.org) + * Copytight (C) 1999, 2000 Silicon Graphics, Inc. + */ +#include <linux/bcd.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/kernel_stat.h> +#include <linux/param.h> +#include <linux/time.h> +#include <linux/timex.h> +#include <linux/mm.h> + +#include <asm/time.h> +#include <asm/pgtable.h> +#include <asm/sgialib.h> +#include <asm/sn/ioc3.h> +#include <asm/m48t35.h> +#include <asm/sn/klconfig.h> +#include <asm/sn/arch.h> +#include <asm/sn/addrs.h> +#include <asm/sn/sn_private.h> +#include <asm/sn/sn0/ip27.h> +#include <asm/sn/sn0/hub.h> + +/* + * This is a hack; we really need to figure these values out dynamically + * + * Since 800 ns works very well with various HUB frequencies, such as + * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. + * + * Ralf: which clock rate is used to feed the counter? + */ +#define NSEC_PER_CYCLE 800 +#define CYCLES_PER_SEC (NSEC_PER_SEC/NSEC_PER_CYCLE) +#define CYCLES_PER_JIFFY (CYCLES_PER_SEC/HZ) + +#define TICK_SIZE (tick_nsec / 1000) + +static unsigned long ct_cur[NR_CPUS]; /* What counter should be at next timer irq */ +static long last_rtc_update; /* Last time the rtc clock got updated */ + +extern volatile unsigned long wall_jiffies; + +#if 0 +static int set_rtc_mmss(unsigned long nowtime) +{ + int retval = 0; + int real_seconds, real_minutes, cmos_minutes; + struct m48t35_rtc *rtc; + nasid_t nid; + + nid = get_nasid(); + rtc = (struct m48t35_rtc *)(KL_CONFIG_CH_CONS_INFO(nid)->memory_base + + IOC3_BYTEBUS_DEV0); + + rtc->control |= M48T35_RTC_READ; + cmos_minutes = BCD2BIN(rtc->min); + rtc->control &= ~M48T35_RTC_READ; + + /* + * Since we're only adjusting minutes and seconds, don't interfere with + * hour overflow. This avoids messing with unknown time zones but + * requires your RTC not to be off by more than 15 minutes + */ + real_seconds = nowtime % 60; + real_minutes = nowtime / 60; + if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1) + real_minutes += 30; /* correct for half hour time zone */ + real_minutes %= 60; + + if (abs(real_minutes - cmos_minutes) < 30) { + real_seconds = BIN2BCD(real_seconds); + real_minutes = BIN2BCD(real_minutes); + rtc->control |= M48T35_RTC_SET; + rtc->sec = real_seconds; + rtc->min = real_minutes; + rtc->control &= ~M48T35_RTC_SET; + } else { + printk(KERN_WARNING + "set_rtc_mmss: can't update from %d to %d\n", + cmos_minutes, real_minutes); + retval = -1; + } + + return retval; +} +#endif + +void ip27_rt_timer_interrupt(struct pt_regs *regs) +{ + int cpu = smp_processor_id(); + int cpuA = cputoslice(cpu) == 0; + int irq = 9; /* XXX Assign number */ + + irq_enter(); + write_seqlock(&xtime_lock); + +again: + LOCAL_HUB_S(cpuA ? PI_RT_PEND_A : PI_RT_PEND_B, 0); /* Ack */ + ct_cur[cpu] += CYCLES_PER_JIFFY; + LOCAL_HUB_S(cpuA ? PI_RT_COMPARE_A : PI_RT_COMPARE_B, ct_cur[cpu]); + + if (LOCAL_HUB_L(PI_RT_COUNT) >= ct_cur[cpu]) + goto again; + + kstat_this_cpu.irqs[irq]++; /* kstat only for bootcpu? */ + + if (cpu == 0) + do_timer(regs); + + update_process_times(user_mode(regs)); + + /* + * 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 when a second starts. + */ + if ((time_status & STA_UNSYNC) == 0 && + 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_set_time(xtime.tv_sec) == 0) { + last_rtc_update = xtime.tv_sec; + } else { + last_rtc_update = xtime.tv_sec - 600; + /* do it again in 60 s */ + } + } + + write_sequnlock(&xtime_lock); + irq_exit(); +} + +unsigned long ip27_do_gettimeoffset(void) +{ + unsigned long ct_cur1; + ct_cur1 = REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT) + CYCLES_PER_JIFFY; + return (ct_cur1 - ct_cur[0]) * NSEC_PER_CYCLE / 1000; +} + +/* Includes for ioc3_init(). */ +#include <asm/sn/types.h> +#include <asm/sn/sn0/addrs.h> +#include <asm/sn/sn0/hubni.h> +#include <asm/sn/sn0/hubio.h> +#include <asm/pci/bridge.h> + +static __init unsigned long get_m48t35_time(void) +{ + unsigned int year, month, date, hour, min, sec; + struct m48t35_rtc *rtc; + nasid_t nid; + + nid = get_nasid(); + rtc = (struct m48t35_rtc *)(KL_CONFIG_CH_CONS_INFO(nid)->memory_base + + IOC3_BYTEBUS_DEV0); + + rtc->control |= M48T35_RTC_READ; + sec = rtc->sec; + min = rtc->min; + hour = rtc->hour; + date = rtc->date; + month = rtc->month; + year = rtc->year; + rtc->control &= ~M48T35_RTC_READ; + + sec = BCD2BIN(sec); + min = BCD2BIN(min); + hour = BCD2BIN(hour); + date = BCD2BIN(date); + month = BCD2BIN(month); + year = BCD2BIN(year); + + year += 1970; + + return mktime(year, month, date, hour, min, sec); +} + +static void ip27_timer_setup(struct irqaction *irq) +{ + /* over-write the handler, we use our own way */ + irq->handler = no_action; + + /* setup irqaction */ +// setup_irq(IP27_TIMER_IRQ, irq); /* XXX Can't do this yet. */ +} + +void __init ip27_time_init(void) +{ + xtime.tv_sec = get_m48t35_time(); + xtime.tv_nsec = 0; + + do_gettimeoffset = ip27_do_gettimeoffset; + + board_timer_setup = ip27_timer_setup; +} + +void __init cpu_time_init(void) +{ + lboard_t *board; + klcpu_t *cpu; + int cpuid; + + /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */ + board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27); + if (!board) + panic("Can't find board info for myself."); + + cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX; + cpu = (klcpu_t *) KLCF_COMP(board, cpuid); + if (!cpu) + panic("No information about myself?"); + + printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed); + + set_c0_status(SRB_TIMOCLK); +} + +void __init hub_rtc_init(cnodeid_t cnode) +{ + /* + * We only need to initialize the current node. + * If this is not the current node then it is a cpuless + * node and timeouts will not happen there. + */ + if (get_compact_nodeid() == cnode) { + int cpu = smp_processor_id(); + LOCAL_HUB_S(PI_RT_EN_A, 1); + LOCAL_HUB_S(PI_RT_EN_B, 1); + LOCAL_HUB_S(PI_PROF_EN_A, 0); + LOCAL_HUB_S(PI_PROF_EN_B, 0); + ct_cur[cpu] = CYCLES_PER_JIFFY; + LOCAL_HUB_S(PI_RT_COMPARE_A, ct_cur[cpu]); + LOCAL_HUB_S(PI_RT_COUNT, 0); + LOCAL_HUB_S(PI_RT_PEND_A, 0); + LOCAL_HUB_S(PI_RT_COMPARE_B, ct_cur[cpu]); + LOCAL_HUB_S(PI_RT_COUNT, 0); + LOCAL_HUB_S(PI_RT_PEND_B, 0); + } +} |