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/*
* arch/arm/mach-ns9xxx/time-ns921x.c
*
* Copyright (C) 2007 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 <mach/regs-sys-ns921x.h>
#include <mach/irqs.h>
#include "irq.h"
#include "processor-ns921x.h"
#define TIMER_CLOCKSOURCE 0
#define TIMER_CLOCKEVENT 1
static u32 latch;
static cycle_t ns921x_clocksource_read(void)
{
return __raw_readl(SYS_TRC(TIMER_CLOCKSOURCE));
}
static struct clocksource ns921x_clocksource = {
.name = "ns921x-timer" __stringify(TIMER_CLOCKSOURCE),
.rating = 300,
.read = ns921x_clocksource_read,
.mask = CLOCKSOURCE_MASK(32),
.shift = 20,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static void ns921x_clockevent_setmode(enum clock_event_mode mode,
struct clock_event_device *clk)
{
u32 oldtc, tc = __raw_readl(SYS_TC(TIMER_CLOCKEVENT));
oldtc = tc;
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
__raw_writel(latch, SYS_TRCC(TIMER_CLOCKEVENT));
REGSET(tc, SYS_TCx, RELENBL, EN);
REGSET(tc, SYS_TCx, INTSEL, EN);
REGSET(tc, SYS_TCx, TE, EN);
break;
case CLOCK_EVT_MODE_ONESHOT:
REGSET(tc, SYS_TCx, RELENBL, DIS);
REGSET(tc, SYS_TCx, INTSEL, EN);
REGSET(tc, SYS_TCx, TE, DIS);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
default:
REGSET(tc, SYS_TCx, TE, DIS);
break;
}
/* ack an possibly pending irq
* This might stuck the irq priority encoder, but only until the next
* timer irq ... */
if (REGGET(tc, SYS_TCx, TE) == SYS_TCx_TE_DIS &&
REGGET(oldtc, SYS_TCx, TE) == SYS_TCx_TE_EN) {
REGSETIM(tc, SYS_TCx, INTCLR, 1);
__raw_writel(tc, SYS_TC(TIMER_CLOCKEVENT));
REGSETIM(tc, SYS_TCx, INTCLR, 0);
}
__raw_writel(tc, SYS_TC(TIMER_CLOCKEVENT));
}
static int ns921x_clockevent_setnextevent(unsigned long evt,
struct clock_event_device *clk)
{
u32 tc = __raw_readl(SYS_TC(TIMER_CLOCKEVENT));
if (REGGET(tc, SYS_TCx, TE)) {
REGSET(tc, SYS_TCx, TE, DIS);
__raw_writel(tc, SYS_TC(TIMER_CLOCKEVENT));
}
REGSET(tc, SYS_TCx, TE, EN);
__raw_writel(evt, SYS_TRCC(TIMER_CLOCKEVENT));
__raw_writel(tc, SYS_TC(TIMER_CLOCKEVENT));
return 0;
}
static struct clock_event_device ns921x_clockevent_device = {
.name = "ns921x-timer" __stringify(TIMER_CLOCKEVENT),
.shift = 20,
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = ns921x_clockevent_setmode,
.set_next_event = ns921x_clockevent_setnextevent,
};
static irqreturn_t ns921x_clockevent_handler(int irq, void *dev_id)
{
int timerno = irq - IRQ_NS921X_TIMER0;
u32 tc;
struct clock_event_device *evt = &ns921x_clockevent_device;
/* clear irq */
tc = __raw_readl(SYS_TC(timerno));
if (REGGET(tc, SYS_TCx, RELENBL) == SYS_TCx_RELENBL_DIS) {
REGSET(tc, SYS_TCx, TE, DIS);
__raw_writel(tc, SYS_TC(timerno));
}
REGSETIM(tc, SYS_TCx, INTCLR, 1);
__raw_writel(tc, SYS_TC(timerno));
REGSETIM(tc, SYS_TCx, INTCLR, 0);
__raw_writel(tc, SYS_TC(timerno));
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction ns921x_clockevent_action = {
.name = "ns921x-timer" __stringify(TIMER_CLOCKEVENT),
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = ns921x_clockevent_handler,
};
static void __init ns921x_timer_init(void)
{
int tc;
tc = __raw_readl(SYS_TC(TIMER_CLOCKSOURCE));
if (REGGET(tc, SYS_TCx, TE)) {
REGSET(tc, SYS_TCx, TE, DIS);
__raw_writel(tc, SYS_TC(TIMER_CLOCKSOURCE));
}
__raw_writel(0, SYS_TRC(TIMER_CLOCKSOURCE));
REGSET(tc, SYS_TCx, TE, EN);
REGSET(tc, SYS_TCx, DEBUG, STOP);
REGSET(tc, SYS_TCx, TCS, 2AHB);
REGSET(tc, SYS_TCx, MODE, INTERNAL);
REGSET(tc, SYS_TCx, INTSEL, DIS);
REGSET(tc, SYS_TCx, UPDOWN, UP);
REGSET(tc, SYS_TCx, BITTIMER, 32);
REGSET(tc, SYS_TCx, RELENBL, EN);
__raw_writel(tc, SYS_TC(TIMER_CLOCKSOURCE));
ns921x_clocksource.mult = clocksource_hz2mult(ns921x_ahbclock() * 2,
ns921x_clocksource.shift);
clocksource_register(&ns921x_clocksource);
latch = SH_DIV(ns921x_ahbclock() * 2, HZ, 0);
tc = __raw_readl(SYS_TC(TIMER_CLOCKEVENT));
REGSET(tc, SYS_TCx, TE, DIS);
REGSET(tc, SYS_TCx, DEBUG, STOP);
REGSET(tc, SYS_TCx, TCS, 2AHB);
REGSET(tc, SYS_TCx, MODE, INTERNAL);
REGSET(tc, SYS_TCx, INTSEL, DIS);
REGSET(tc, SYS_TCx, UPDOWN, DOWN);
REGSET(tc, SYS_TCx, BITTIMER, 32);
REGSET(tc, SYS_TCx, RELENBL, EN);
__raw_writel(tc, SYS_TC(TIMER_CLOCKEVENT));
ns921x_clockevent_device.mult = div_sc(ns921x_ahbclock() * 2,
NSEC_PER_SEC, ns921x_clockevent_device.shift);
ns921x_clockevent_device.max_delta_ns =
clockevent_delta2ns(-1, &ns921x_clockevent_device);
ns921x_clockevent_device.min_delta_ns =
clockevent_delta2ns(1, &ns921x_clockevent_device);
ns921x_clockevent_device.cpumask = cpumask_of_cpu(0);
clockevents_register_device(&ns921x_clockevent_device);
setup_irq(IRQ_NS921X_TIMER0 + TIMER_CLOCKEVENT,
&ns921x_clockevent_action);
}
struct sys_timer ns921x_timer = {
.init = ns921x_timer_init,
};
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