root/include/asm-mn10300/unit-asb2303/timex.h

INCLUDED FROM

DEFINITIONS

1. startup_jiffies_counter
2. shutdown_jiffies_counter
3. startup_timestamp_counter
4. shutdown_timestamp_counter
5. read_timestamp_counter

/* ASB2303-specific timer specifcations
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * 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

#ifndef __ASSEMBLY__
#include <linux/irq.h>
#endif /* __ASSEMBLY__ */

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

/*
 * jiffies counter specifications
 */

#define TMJCBR_MAX              0xffff
#define TMJCBC                  TM01BC

#define TMJCMD                  TM01MD
#define TMJCBR                  TM01BR
#define TMJCIRQ                 TM1IRQ
#define TMJCICR                 TM1ICR
#define TMJCICR_LEVEL           GxICR_LEVEL_5

#ifndef __ASSEMBLY__

static inline void startup_jiffies_counter(void)
{
        unsigned rate;
        u16 md, t16;

        /* use as little prescaling as possible to avoid losing accuracy */
        md = TM0MD_SRC_IOCLK;
        rate = MN10300_JCCLK / HZ;

        if (rate > TMJCBR_MAX) {
                md = TM0MD_SRC_IOCLK_8;
                rate = MN10300_JCCLK / 8 / HZ;

                if (rate > TMJCBR_MAX) {
                        md = TM0MD_SRC_IOCLK_32;
                        rate = MN10300_JCCLK / 32 / HZ;

                        if (rate > TMJCBR_MAX)
                                BUG();
                }
        }

        TMJCBR = rate - 1;
        t16 = TMJCBR;

        TMJCMD =
                md |
                TM1MD_SRC_TM0CASCADE << 8 |
                TM0MD_INIT_COUNTER |
                TM1MD_INIT_COUNTER << 8;

        TMJCMD =
                md |
                TM1MD_SRC_TM0CASCADE << 8 |
                TM0MD_COUNT_ENABLE |
                TM1MD_COUNT_ENABLE << 8;

        t16 = TMJCMD;

        TMJCICR |= GxICR_ENABLE | GxICR_DETECT | GxICR_REQUEST;
        t16 = TMJCICR;
}

static inline void shutdown_jiffies_counter(void)
{
}

#endif /* !__ASSEMBLY__ */


/*
 * timestamp counter specifications
 */

#define TMTSCBR_MAX             0xffffffff
#define TMTSCBC                 TM45BC

#ifndef __ASSEMBLY__

static inline void startup_timestamp_counter(void)
{
        /* 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;

        TM4MD = TM4MD_SRC_IOCLK;
        TM4MD |= TM4MD_INIT_COUNTER;
        TM4MD &= ~TM4MD_INIT_COUNTER;
        TM4ICR = 0;

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

        TM5MD |= TM5MD_COUNT_ENABLE;
        TM4MD |= TM4MD_COUNT_ENABLE;
}

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

/*
 * 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 */