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timer16.c

/*
 *  linux/arch/h8300/kernel/timer/timer16.c
 *
 *  Yoshinori Sato <ysato@users.sourcefoge.jp>
 *
 *  16bit 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>

/* 16bit timer */
#if CONFIG_H8300_TIMER16_CH == 0
#define _16BASE   0xffff78
#define _16IRQ    24
#elif CONFIG_H8300_TIMER16_CH == 1
#define _16BASE   0xffff80
#define _16IRQ    28
#elif CONFIG_H8300_TIMER16_CH == 2
#define _16BASE   0xffff88
#define _16IRQ    32
#else
#error Unknown timer channel.
#endif

#define TCR 0
#define TIOR      1
#define TCNT      2
#define GRA 4
#define GRB 6

#define H8300_TIMER_FREQ CONFIG_CPU_CLOCK*10000 /* Timer input freq. */

static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
      h8300_timer_tick();
      ctrl_bclr(CONFIG_H8300_TIMER16_CH, TISRA);
      return IRQ_HANDLED;
}

static struct irqaction timer16_irq = {
      .name       = "timer-16",
      .handler    = timer_interrupt,
      .flags            = IRQF_DISABLED | IRQF_TIMER,
};

static const int __initdata 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(_16IRQ, &timer16_irq);

      /* initalize timer */
      ctrl_outb(0, TSTR);
      ctrl_outb(CCLR0 | div, _16BASE + TCR);
      ctrl_outw(cnt, _16BASE + GRA);
      ctrl_bset(4 + CONFIG_H8300_TIMER16_CH, TISRA);
      ctrl_bset(CONFIG_H8300_TIMER16_CH, TSTR);
}

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