/*
 *  linux/arch/armnommu/mach-espd_4510b/time.c
 *
 *  Copyright (C) SAMSUNG ELECTRONICS 
 *                      Hyok S. Choi <hyok.choi@samsung.com>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/system.h>
#include <asm/leds.h>
#include <asm/mach-types.h>
                                                                                                                                           
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mach/time.h>
#include <asm/uaccess.h>
#include <asm/hardware.h>
#include <asm/arch/timex.h>
#include <asm/mach/irq.h>
                                                                                                                                           
#define CLOCKS_PER_USEC (CONFIG_ARM_CLK/1000000)
                                                                                                                                           
static volatile unsigned long timer_cnt;
                                                                                                                                           
unsigned long s3c4510b_gettimeoffset (void)
{
        unsigned long usec;
                                                                                                                                           
        /* returns microseconds -- timer 1 is free running in countdown mode */
        usec = 0xFFFFFFFF - inl( REG_TCNT1);
        usec /= CLOCKS_PER_USEC;
                                                                                                                                           
        return usec;
}
                                                                                                                                           
static irqreturn_t
s3c4510b_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
                                                                                                                                           
        timer_cnt++;
                                                                                                                                           
#ifdef CONFIG_ARCH_ESPD_4510B
        if ( ! (timer_cnt % (HZ/4))) {
                LED_TOGGLE(0);
        }
#endif
        timer_tick(regs);
                                                                                                                                           
        return IRQ_HANDLED;
}

static struct irqaction s3c4510b_timer_irq = {
        .name           = "S3C4510b Timer Tick",
        .flags          = SA_INTERRUPT | SA_TIMER,
        .handler        = s3c4510b_timer_interrupt
};

                                                                                                                                           
/*
 * Set up timer interrupt
 */
                                                                                                                                           
void __init  s3c4510b_time_init (void)
{
        u_int32_t period;
                                                                                                                                           
        /*
         * disable and clear timers 0 and 1.  set both timers to
         * interval mode.
         */
        outl( 0x0, REG_TMOD);
        /* clear any pending interrupts */
        outl( 0x1FFFFF, REG_INTPEND);
                                                                                                                                           
        timer_cnt = 0;
                                                                                                                                           
        /* initialize the timer period */
        period = (CLOCK_TICK_RATE / HZ);
        outl( period, REG_TDATA0);
                                                                                                                                           
        /* set timer1 to continually count down from FFFFFFFF */
        outl( 0xFFFFFFFF, REG_TDATA1);
                                                                                                                                           
//      printk(KERN_INFO "time_init():  TICK_RATE: %u, HZ: %u, period: %u\n", CLOCK_TICK_RATE, HZ, period);
                                                                                                                                           
        s3c4510b_timer_irq.handler = s3c4510b_timer_interrupt;
                                                                                                                                           
        /* set up the interrupt vevtor for timer 0 match */
        setup_irq( INT_TIMER0, &s3c4510b_timer_irq);
                                                                                                                                           
        /* enable the timer IRQ */
        INT_ENABLE( INT_TIMER0);
                                                                                                                                           
        /* let timer 0 run... */
        outl( TM0_RUN | TM1_RUN, REG_TMOD);
}
                                                                                                                                           
struct sys_timer s3c4510b_timer = {
        .init           = s3c4510b_time_init,
        .offset         = s3c4510b_gettimeoffset,
};