/*
 *  linux/arch/h8300/kernel/timer/tpu.c
 *
 *  Yoshinori Sato <ysato@users.sourceforge.jp>
 *
 *  TPU 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/regs267x.h>

/* TPU */
#if CONFIG_H8300_TPU_CH == 0
#define TPUBASE	0xffffd0
#define TPUIRQ	40
#elif CONFIG_H8300_TPU_CH == 1
#define TPUBASE	0xffffe0
#define TPUIRQ	48
#elif CONFIG_H8300_TPU_CH == 2
#define TPUBASE	0xfffff0
#define TPUIRQ	52
#elif CONFIG_H8300_TPU_CH == 3
#define TPUBASE	0xfffe80
#define TPUIRQ	56
#elif CONFIG_H8300_TPU_CH == 4
#define TPUBASE	0xfffe90
#define TPUIRQ	64
#else
#error Unknown timer channel.
#endif

#define _TCR	0
#define _TMDR	1
#define _TIOR	2
#define _TIER	4
#define _TSR	5
#define _TCNT	6
#define _GRA	8
#define _GRB	10

#define CCLR0	0x20

static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
	h8300_timer_tick();
	ctrl_bclr(0, TPUBASE + _TSR);
	return IRQ_HANDLED;
}

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

static const int __initconst divide_rate[] = {
#if CONFIG_H8300_TPU_CH == 0
	1,4,16,64,0,0,0,0,
#elif (CONFIG_H8300_TPU_CH == 1) || (CONFIG_H8300_TPU_CH == 5)
	1,4,16,64,0,0,256,0,
#elif (CONFIG_H8300_TPU_CH == 2) || (CONFIG_H8300_TPU_CH == 4)
	1,4,16,64,0,0,0,1024,
#elif CONFIG_H8300_TPU_CH == 3
	1,4,16,64,0,1024,256,4096,
#endif
};

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

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

	setup_irq(TPUIRQ, &tpu_irq);

	/* TPU module enabled */
	ctrl_bclr(3, MSTPCRH);

	ctrl_outb(0, TSTR);
	ctrl_outb(CCLR0 | div, TPUBASE + _TCR);
	ctrl_outb(0, TPUBASE + _TMDR);
	ctrl_outw(0, TPUBASE + _TIOR);
	ctrl_outb(0x01, TPUBASE + _TIER);
	ctrl_outw(cnt, TPUBASE + _GRA);
	ctrl_bset(CONFIG_H8300_TPU_CH, TSTR);
}