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/*
* Copyright 2001, 2002, 2003 MontaVista Software Inc.
* Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
* Copyright (C) 2007 Ralf Baechle (ralf@linux-mips.org)
*
* Common time service routines for MIPS machines. See
* Documents/MIPS/README.txt.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/param.h>
#include <linux/time.h>
#include <linux/timer.h>
#include <linux/smp.h>
#include <linux/kernel_stat.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
#include <asm/time.h>
#include <asm/hardirq.h>
#include <asm/div64.h>
#include <asm/debug.h>
#include <int.h>
#include <cm.h>
static unsigned long cpj;
static cycle_t hpt_read(void)
{
return read_c0_count2();
}
static struct clocksource pnx_clocksource = {
.name = "pnx8xxx",
.rating = 200,
.read = hpt_read,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static void timer_ack(void)
{
write_c0_compare(cpj);
}
static irqreturn_t pnx8xxx_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *c = dev_id;
/* clear MATCH, signal the event */
c->event_handler(c);
return IRQ_HANDLED;
}
static struct irqaction pnx8xxx_timer_irq = {
.handler = pnx8xxx_timer_interrupt,
.flags = IRQF_DISABLED | IRQF_PERCPU,
.name = "pnx8xxx_timer",
};
static irqreturn_t monotonic_interrupt(int irq, void *dev_id)
{
/* Timer 2 clear interrupt */
write_c0_compare2(-1);
return IRQ_HANDLED;
}
static struct irqaction monotonic_irqaction = {
.handler = monotonic_interrupt,
.flags = IRQF_DISABLED,
.name = "Monotonic timer",
};
static int pnx8xxx_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
write_c0_compare(delta);
return 0;
}
static struct clock_event_device pnx8xxx_clockevent = {
.name = "pnx8xxx_clockevent",
.features = CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = pnx8xxx_set_next_event,
};
/*
* plat_time_init() - it does the following things:
*
* 1) plat_time_init() -
* a) (optional) set up RTC routines,
* b) (optional) calibrate and set the mips_hpt_frequency
* (only needed if you intended to use cpu counter as timer interrupt
* source)
*/
__init void plat_time_init(void)
{
unsigned int configPR;
unsigned int n;
unsigned int m;
unsigned int p;
unsigned int pow2p;
clockevents_register_device(&pnx8xxx_clockevent);
clocksource_register(&pnx_clocksource);
setup_irq(PNX8550_INT_TIMER1, &pnx8xxx_timer_irq);
setup_irq(PNX8550_INT_TIMER2, &monotonic_irqaction);
/* Timer 1 start */
configPR = read_c0_config7();
configPR &= ~0x00000008;
write_c0_config7(configPR);
/* Timer 2 start */
configPR = read_c0_config7();
configPR &= ~0x00000010;
write_c0_config7(configPR);
/* Timer 3 stop */
configPR = read_c0_config7();
configPR |= 0x00000020;
write_c0_config7(configPR);
/* PLL0 sets MIPS clock (PLL1 <=> TM1, PLL6 <=> TM2, PLL5 <=> mem) */
/* (but only if CLK_MIPS_CTL select value [bits 3:1] is 1: FIXME) */
n = (PNX8550_CM_PLL0_CTL & PNX8550_CM_PLL_N_MASK) >> 16;
m = (PNX8550_CM_PLL0_CTL & PNX8550_CM_PLL_M_MASK) >> 8;
p = (PNX8550_CM_PLL0_CTL & PNX8550_CM_PLL_P_MASK) >> 2;
pow2p = (1 << p);
db_assert(m != 0 && pow2p != 0);
/*
* Compute the frequency as in the PNX8550 User Manual 1.0, p.186
* (a.k.a. 8-10). Divide by HZ for a timer offset that results in
* HZ timer interrupts per second.
*/
mips_hpt_frequency = 27UL * ((1000000UL * n)/(m * pow2p));
cpj = (mips_hpt_frequency + HZ / 2) / HZ;
write_c0_count(0);
timer_ack();
/* Setup Timer 2 */
write_c0_count2(0);
write_c0_compare2(0xffffffff);
}
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