linux/arch/arm/mach-ns9xxx/time.c

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/*
* arch/arm/mach-ns9xxx/time.c
*
* Copyright (C) 2006 by Digi International Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/stringify.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <asm/arch-ns9xxx/regs-sys.h>
#include <asm/arch-ns9xxx/clock.h>
#include <asm/arch-ns9xxx/irqs.h>
#include <asm/arch/system.h>
#include "generic.h"
#define TIMER_CLOCKSOURCE 0
#define TIMER_CLOCKEVENT 1
static u32 latch;
static cycle_t ns9xxx_clocksource_read(void)
{
return SYS_TR(TIMER_CLOCKSOURCE);
}
static struct clocksource ns9xxx_clocksource = {
.name = "ns9xxx-timer" __stringify(TIMER_CLOCKSOURCE),
.rating = 300,
.read = ns9xxx_clocksource_read,
.mask = CLOCKSOURCE_MASK(32),
.shift = 20,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static void ns9xxx_clockevent_setmode(enum clock_event_mode mode,
struct clock_event_device *clk)
{
u32 tc = SYS_TC(TIMER_CLOCKEVENT);
switch(mode) {
case CLOCK_EVT_MODE_PERIODIC:
SYS_TRC(TIMER_CLOCKEVENT) = latch;
REGSET(tc, SYS_TCx, REN, EN);
REGSET(tc, SYS_TCx, INTS, EN);
REGSET(tc, SYS_TCx, TEN, EN);
break;
case CLOCK_EVT_MODE_ONESHOT:
REGSET(tc, SYS_TCx, REN, DIS);
REGSET(tc, SYS_TCx, INTS, EN);
/* fall through */
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
default:
REGSET(tc, SYS_TCx, TEN, DIS);
break;
}
SYS_TC(TIMER_CLOCKEVENT) = tc;
}
static int ns9xxx_clockevent_setnextevent(unsigned long evt,
struct clock_event_device *clk)
{
u32 tc = SYS_TC(TIMER_CLOCKEVENT);
if (REGGET(tc, SYS_TCx, TEN)) {
REGSET(tc, SYS_TCx, TEN, DIS);
SYS_TC(TIMER_CLOCKEVENT) = tc;
}
REGSET(tc, SYS_TCx, TEN, EN);
SYS_TRC(TIMER_CLOCKEVENT) = evt;
SYS_TC(TIMER_CLOCKEVENT) = tc;
return 0;
}
static struct clock_event_device ns9xxx_clockevent_device = {
.name = "ns9xxx-timer" __stringify(TIMER_CLOCKEVENT),
.shift = 20,
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = ns9xxx_clockevent_setmode,
.set_next_event = ns9xxx_clockevent_setnextevent,
};
static irqreturn_t ns9xxx_clockevent_handler(int irq, void *dev_id)
{
int timerno = irq - IRQ_TIMER0;
u32 tc;
struct clock_event_device *evt = &ns9xxx_clockevent_device;
/* clear irq */
tc = SYS_TC(timerno);
if (REGGET(tc, SYS_TCx, REN) == SYS_TCx_REN_DIS) {
REGSET(tc, SYS_TCx, TEN, DIS);
SYS_TC(timerno) = tc;
}
REGSET(tc, SYS_TCx, INTC, SET);
SYS_TC(timerno) = tc;
REGSET(tc, SYS_TCx, INTC, UNSET);
SYS_TC(timerno) = tc;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction ns9xxx_clockevent_action = {
.name = "ns9xxx-timer" __stringify(TIMER_CLOCKEVENT),
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = ns9xxx_clockevent_handler,
};
static void __init ns9xxx_timer_init(void)
{
int tc;
tc = SYS_TC(TIMER_CLOCKSOURCE);
if (REGGET(tc, SYS_TCx, TEN)) {
REGSET(tc, SYS_TCx, TEN, DIS);
SYS_TC(TIMER_CLOCKSOURCE) = tc;
}
SYS_TRC(TIMER_CLOCKSOURCE) = 0;
REGSET(tc, SYS_TCx, TEN, EN);
REGSET(tc, SYS_TCx, TDBG, STOP);
REGSET(tc, SYS_TCx, TLCS, CPU);
REGSET(tc, SYS_TCx, TM, IEE);
REGSET(tc, SYS_TCx, INTS, DIS);
REGSET(tc, SYS_TCx, UDS, UP);
REGSET(tc, SYS_TCx, TSZ, 32);
REGSET(tc, SYS_TCx, REN, EN);
SYS_TC(TIMER_CLOCKSOURCE) = tc;
ns9xxx_clocksource.mult = clocksource_hz2mult(ns9xxx_cpuclock(),
ns9xxx_clocksource.shift);
clocksource_register(&ns9xxx_clocksource);
latch = SH_DIV(ns9xxx_cpuclock(), HZ, 0);
tc = SYS_TC(TIMER_CLOCKEVENT);
REGSET(tc, SYS_TCx, TEN, DIS);
REGSET(tc, SYS_TCx, TDBG, STOP);
REGSET(tc, SYS_TCx, TLCS, CPU);
REGSET(tc, SYS_TCx, TM, IEE);
REGSET(tc, SYS_TCx, INTS, DIS);
REGSET(tc, SYS_TCx, UDS, DOWN);
REGSET(tc, SYS_TCx, TSZ, 32);
REGSET(tc, SYS_TCx, REN, EN);
SYS_TC(TIMER_CLOCKEVENT) = tc;
ns9xxx_clockevent_device.mult = div_sc(ns9xxx_cpuclock(),
NSEC_PER_SEC, ns9xxx_clockevent_device.shift);
ns9xxx_clockevent_device.max_delta_ns =
clockevent_delta2ns(-1, &ns9xxx_clockevent_device);
ns9xxx_clockevent_device.min_delta_ns =
clockevent_delta2ns(1, &ns9xxx_clockevent_device);
ns9xxx_clockevent_device.cpumask = cpumask_of_cpu(0);
clockevents_register_device(&ns9xxx_clockevent_device);
setup_irq(IRQ_TIMER0 + TIMER_CLOCKEVENT, &ns9xxx_clockevent_action);
}
struct sys_timer ns9xxx_timer = {
.init = ns9xxx_timer_init,
};