linux/arch/mips/sgi-ip27/ip27-timer.c
Ralf Baechle 725d7b36c3 [MIPS] IP27: Fix slice logic to work for arbitrary number of slices.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-29 19:35:35 +00:00

305 lines
7.2 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/clockchips.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>
#define TICK_SIZE (tick_nsec / 1000)
#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
/* 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>
unsigned long read_persistent_clock(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 int rt_next_event(unsigned long delta, struct clock_event_device *evt)
{
unsigned int cpu = smp_processor_id();
int slice putoslice(cpu);
unsigned long cnt;
cnt = LOCAL_HUB_L(PI_RT_COUNT);
cnt += delta;
LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
}
static void rt_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
switch (mode) {
case CLOCK_EVT_MODE_ONESHOT:
/* The only mode supported */
break;
case CLOCK_EVT_MODE_PERIODIC:
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
/* Nothing to do */
break;
}
}
unsigned int rt_timer_irq;
static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
{
struct clock_event_device *cd = dev_id;
unsigned int cpu = smp_processor_id();
int slice = cputoslice(cpu);
/*
* Ack
*/
LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, cnt);
cd->event_handler(cd);
return IRQ_HANDLED;
}
struct irqaction hub_rt_irqaction = {
.handler = hub_rt_counter_handler,
.flags = IRQF_DISABLED | IRQF_PERCPU,
.name = "hub-rt",
};
/*
* 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)
static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
static DEFINE_PER_CPU(char [11], hub_rt_name);
static void __cpuinit hub_rt_clock_event_init(void)
{
unsigned int cpu = smp_processor_id();
struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
unsigned char *name = per_cpu(hub_rt_name, cpu);
int irq = rt_timer_irq;
sprintf(name, "hub-rt %d", cpu);
cd->name = "HUB-RT",
cd->features = CLOCK_EVT_FEAT_ONESHOT,
clockevent_set_clock(cd, CYCLES_PER_SEC);
cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd);
cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
cd->rating = 200,
cd->irq = irq,
cd->cpumask = cpumask_of_cpu(cpu),
cd->rating = 300,
cd->set_next_event = rt_next_event,
cd->set_mode = rt_set_mode,
clockevents_register_device(cd);
}
static void __init hub_rt_clock_event_global_init(void)
{
unsigned int irq;
do {
smp_wmb();
irq = rt_timer_irq;
if (irq)
break;
irq = allocate_irqno();
if (irq < 0)
panic("Allocation of irq number for timer failed");
} while (xchg(&rt_timer_irq, irq));
set_irq_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
setup_irq(irq, &hub_rt_irqaction);
}
static cycle_t hub_rt_read(void)
{
return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
}
struct clocksource hub_rt_clocksource = {
.name = "HUB-RT",
.rating = 200,
.read = hub_rt_read,
.mask = CLOCKSOURCE_MASK(52),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static void __init hub_rt_clocksource_init(void)
{
struct clocksource *cs = &hub_rt_clocksource;
clocksource_set_clock(cs, CYCLES_PER_SEC);
clocksource_register(cs);
}
void __init plat_time_init(void)
{
hub_rt_clocksource_init();
hub_rt_clock_event_global_init();
}
void __cpuinit 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);
hub_rt_clock_event_init();
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) {
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);
LOCAL_HUB_S(PI_RT_COUNT, 0);
LOCAL_HUB_S(PI_RT_PEND_A, 0);
LOCAL_HUB_S(PI_RT_PEND_B, 0);
}
}