timex.h

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/* ASB2303-specific timer specifications
 *
 * Copyright (C) 2007, 2010 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#ifndef _ASM_UNIT_TIMEX_H
#define _ASM_UNIT_TIMEX_H

#include <asm/timer-regs.h>
#include <unit/clock.h>
#include <asm/param.h>

/*
 * jiffies counter specifications
 */

#define TMJCBR_MAX      0xffff
#define TMJCIRQ         TM1IRQ
#define TMJCICR         TM1ICR

#ifndef __ASSEMBLY__

#define MN10300_SRC_IOCLK   MN10300_IOCLK

#ifndef HZ
# error HZ undeclared.
#endif /* !HZ */
/* use as little prescaling as possible to avoid losing accuracy */
#if (MN10300_SRC_IOCLK + HZ / 2) / HZ - 1 <= TMJCBR_MAX
# define IOCLK_PRESCALE     1
# define JC_TIMER_CLKSRC    TM0MD_SRC_IOCLK
# define TSC_TIMER_CLKSRC   TM4MD_SRC_IOCLK
#elif (MN10300_SRC_IOCLK / 8 + HZ / 2) / HZ - 1 <= TMJCBR_MAX
# define IOCLK_PRESCALE     8
# define JC_TIMER_CLKSRC    TM0MD_SRC_IOCLK_8
# define TSC_TIMER_CLKSRC   TM4MD_SRC_IOCLK_8
#elif (MN10300_SRC_IOCLK / 32 + HZ / 2) / HZ - 1 <= TMJCBR_MAX
# define IOCLK_PRESCALE     32
# define JC_TIMER_CLKSRC    TM0MD_SRC_IOCLK_32
# define TSC_TIMER_CLKSRC   TM4MD_SRC_IOCLK_32
#else
# error You lose.
#endif

#define MN10300_JCCLK       (MN10300_SRC_IOCLK / IOCLK_PRESCALE)
#define MN10300_TSCCLK      (MN10300_SRC_IOCLK / IOCLK_PRESCALE)

#define MN10300_JC_PER_HZ   ((MN10300_JCCLK + HZ / 2) / HZ)
#define MN10300_TSC_PER_HZ  ((MN10300_TSCCLK + HZ / 2) / HZ)

static inline void stop_jiffies_counter(void)
{
    u16 tmp;
    TM01MD = JC_TIMER_CLKSRC | TM1MD_SRC_TM0CASCADE << 8;
    tmp = TM01MD;
}

static inline void reload_jiffies_counter(u32 cnt)
{
    u32 tmp;

    TM01BR = cnt;
    tmp = TM01BR;

    TM01MD = JC_TIMER_CLKSRC |      \
         TM1MD_SRC_TM0CASCADE << 8 |    \
         TM0MD_INIT_COUNTER |       \
         TM1MD_INIT_COUNTER << 8;


    TM01MD = JC_TIMER_CLKSRC |      \
         TM1MD_SRC_TM0CASCADE << 8 |    \
         TM0MD_COUNT_ENABLE |       \
         TM1MD_COUNT_ENABLE << 8;

    tmp = TM01MD;
}

#endif /* !__ASSEMBLY__ */


/*
 * timestamp counter specifications
 */

#define TMTSCBR_MAX     0xffffffff
#define TMTSCBC         TM45BC

#ifndef __ASSEMBLY__

static inline void startup_timestamp_counter(void)
{
    u32 t32;

    /* set up timer 4 & 5 cascaded as a 32-bit counter to count real time
     * - count down from 4Gig-1 to 0 and wrap at IOCLK rate
     */
    TM45BR = TMTSCBR_MAX;
    t32 = TM45BR;

    TM4MD = TSC_TIMER_CLKSRC;
    TM4MD |= TM4MD_INIT_COUNTER;
    TM4MD &= ~TM4MD_INIT_COUNTER;
    TM4ICR = 0;
    t32 = TM4ICR;

    TM5MD = TM5MD_SRC_TM4CASCADE;
    TM5MD |= TM5MD_INIT_COUNTER;
    TM5MD &= ~TM5MD_INIT_COUNTER;
    TM5ICR = 0;
    t32 = TM5ICR;

    TM5MD |= TM5MD_COUNT_ENABLE;
    TM4MD |= TM4MD_COUNT_ENABLE;
    t32 = TM5MD;
    t32 = TM4MD;
}

static inline void shutdown_timestamp_counter(void)
{
    u8 t8;
    TM4MD = 0;
    TM5MD = 0;
    t8 = TM4MD;
    t8 = TM5MD;
}

/*
 * we use a cascaded pair of 16-bit down-counting timers to count I/O
 * clock cycles for the purposes of time keeping
 */
typedef unsigned long cycles_t;

static inline cycles_t read_timestamp_counter(void)
{
    return (cycles_t)~TMTSCBC;
}

#endif /* !__ASSEMBLY__ */

#endif /* _ASM_UNIT_TIMEX_H */