itu.c

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/*
 *  linux/arch/h8300/kernel/timer/itu.c
 *
 *  Yoshinori Sato <[email protected]>
 *
 *  ITU Timer Handler
 *
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/timex.h>

#include <asm/segment.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/regs306x.h>

#if CONFIG_H8300_ITU_CH == 0
#define ITUBASE 0xffff64
#define ITUIRQ  24
#elif CONFIG_H8300_ITU_CH == 1
#define ITUBASE 0xffff6e
#define ITUIRQ  28
#elif CONFIG_H8300_ITU_CH == 2
#define ITUBASE 0xffff78
#define ITUIRQ  32
#elif CONFIG_H8300_ITU_CH == 3
#define ITUBASE 0xffff82
#define ITUIRQ  36
#elif CONFIG_H8300_ITU_CH == 4
#define ITUBASE 0xffff92
#define ITUIRQ  40
#else
#error Unknown timer channel.
#endif

#define TCR 0
#define TIOR    1
#define TIER    2
#define TSR 3
#define TCNT    4
#define GRA 6
#define GRB 8

static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
    h8300_timer_tick();
    ctrl_bclr(IMFA, ITUBASE + TSR);
    return IRQ_HANDLED;
}

static struct irqaction itu_irq = {
    .name       = "itu",
    .handler    = timer_interrupt,
    .flags      = IRQF_DISABLED | IRQF_TIMER,
};

static const int __initconst divide_rate[] = {1, 2, 4, 8};

void __init h8300_timer_setup(void)
{
    unsigned int div;
    unsigned int cnt;

    calc_param(cnt, div, divide_rate, 0x10000);

    setup_irq(ITUIRQ, &itu_irq);

    /* initialize timer */
    ctrl_outb(0, TSTR);
    ctrl_outb(CCLR0 | div, ITUBASE + TCR);
    ctrl_outb(0x01, ITUBASE + TIER);
    ctrl_outw(cnt, ITUBASE + GRA);
    ctrl_bset(CONFIG_H8300_ITU_CH, TSTR);
}