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/*

 *  linux/include/asm-arm/arch-mx1ads/time.h

 *

 * 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

 *

 * Copyright (C) 2002 Shane Nay (shane@minirl.com)

 */

#include <asm/system.h>

/*

 * Where is the timer (VA)?

 */

#define TIMER0_VA_BASE (IO_ADDRESS(MX1ADS_TIM1_BASE)+0x00000000)

#define TIMER1_VA_BASE (IO_ADDRESS(MX1ADS_TIM2_BASE)+0x00000000)

/*

 * How long is the timer interval?

 *

 * Note-

 * Clocking is not accurate enough.  Need to change the input

 * to CLKOUT, and fix what those values are.  However,

 * first need to evaluate what a reasonable value is

 * as several other things depend upon that clock.

 *

 */

#define TIMER_RELOAD    (328)

#define TICKS2USECS(x)  ((x) * 30)

#define TIM_32KHZ       0x08

#define TIM_INTEN       0x10

#define TIM_ENAB        0x01

/*

 * What does it look like?

 */

typedef struct TimerStruct {

        unsigned long TimerControl;

        unsigned long TimerPrescaler;

        unsigned long TimerCompare;

        unsigned long TimerCapture;

        unsigned long TimerCounter;

        unsigned long TimerClear;       /* Clear Status */

} TimerStruct_t;

extern unsigned long (*gettimeoffset) (void);

/*

 * Returns number of ms since last clock interrupt.  Note that interrupts

 * will have been disabled by do_gettimeoffset()

 */

static unsigned long

mx1ads_gettimeoffset(void)

{

        volatile TimerStruct_t *timer1 = (TimerStruct_t *) TIMER1_VA_BASE;

        unsigned long ticks, status;

        /*

         * Get the current number of ticks.  Note that there is a race

         * condition between us reading the timer and checking for

         * an interrupt.  We get around this by ensuring that the

         * counter has not reloaded between our two reads.

         */

        ticks = timer1->TimerCounter;

        /*

         * Interrupt pending?  If so, we've reloaded once already.

         */

        if (timer1->TimerClear & 1)

                ticks += TIMER_RELOAD;

        /*

         * Convert the ticks to usecs

         */

        return TICKS2USECS(ticks);

}

/*

 * IRQ handler for the timer

 */

static void

mx1ads_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)

{

        volatile TimerStruct_t *timer1 =

            (volatile TimerStruct_t *) TIMER1_VA_BASE;

        // ...clear the interrupt

        if (timer1->TimerClear) {

                timer1->TimerClear = 0x0;

        }

        do_timer(regs);

        do_profile(regs);

}

/*

 * Set up timer interrupt, and return the current time in seconds.

 */

static inline void

setup_timer(void)

{

        volatile TimerStruct_t *timer0 =

            (volatile TimerStruct_t *) TIMER0_VA_BASE;

        volatile TimerStruct_t *timer1 =

            (volatile TimerStruct_t *) TIMER1_VA_BASE;

        timer_irq.handler = mx1ads_timer_interrupt;

        /*

         * Initialise to a known state (all timers off, and timing reset)

         */

        timer0->TimerControl = 0;

        timer1->TimerControl = 0;

        timer0->TimerPrescaler = 0;

        timer1->TimerPrescaler = 0;

        timer1->TimerCompare = 328;

        timer1->TimerControl = (TIM_32KHZ | TIM_INTEN | TIM_ENAB);

        /*

         * Make irqs happen for the system timer

         */

        setup_arm_irq(TIM2_INT, &timer_irq);

        gettimeoffset = mx1ads_gettimeoffset;

}