linux/arch/mips/sgi-ip27/ip27-timer.c

277 lines
6.9 KiB
C

/*
* Copytight (C) 1999, 2000, 05, 06 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 */
#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
static unsigned int rt_timer_irq;
void ip27_rt_timer_interrupt(void)
{
int cpu = smp_processor_id();
int cpuA = cputoslice(cpu) == 0;
unsigned int irq = rt_timer_irq;
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(1);
update_process_times(user_mode(get_irq_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 (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_mips_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();
}
/* 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 enable_rt_irq(unsigned int irq)
{
}
static void disable_rt_irq(unsigned int irq)
{
}
static struct irq_chip rt_irq_type = {
.name = "SN HUB RT timer",
.ack = disable_rt_irq,
.mask = disable_rt_irq,
.mask_ack = disable_rt_irq,
.unmask = enable_rt_irq,
.eoi = enable_rt_irq,
};
static struct irqaction rt_irqaction = {
.handler = (irq_handler_t) ip27_rt_timer_interrupt,
.flags = IRQF_DISABLED,
.mask = CPU_MASK_NONE,
.name = "timer"
};
void __init plat_timer_setup(struct irqaction *irq)
{
int irqno = allocate_irqno();
if (irqno < 0)
panic("Can't allocate interrupt number for timer interrupt");
set_irq_chip_and_handler(irqno, &rt_irq_type, handle_percpu_irq);
/* over-write the handler, we use our own way */
irq->handler = no_action;
/* setup irqaction */
irq_desc[irqno].status |= IRQ_PER_CPU;
rt_timer_irq = irqno;
/*
* Only needed to get /proc/interrupt to display timer irq stats
*/
setup_irq(irqno, &rt_irqaction);
}
static cycle_t ip27_hpt_read(void)
{
return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
}
void __init ip27_time_init(void)
{
clocksource_mips.read = ip27_hpt_read;
mips_hpt_frequency = CYCLES_PER_SEC;
xtime.tv_sec = get_m48t35_time();
xtime.tv_nsec = 0;
}
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);
}
}