Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * Copyright (C) 2000, 2001 Broadcom Corporation

 *

 * 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/clocksource.h>

#include <asm/addrspace.h>

#include <asm/io.h>

#include <asm/time.h>

#include <asm/sibyte/sb1250.h>

#include <asm/sibyte/sb1250_regs.h>

#include <asm/sibyte/sb1250_int.h>

#include <asm/sibyte/sb1250_scd.h>

#define SB1250_HPT_NUM          3

#define SB1250_HPT_VALUE        M_SCD_TIMER_CNT /* max value */

/*

 * The HPT is free running from SB1250_HPT_VALUE down to 0 then starts over

 * again.

 */

static cycle_t sb1250_hpt_read(void)

{

        unsigned int count;

        count = G_SCD_TIMER_CNT(__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CNT))));

        return SB1250_HPT_VALUE - count;

}

struct clocksource bcm1250_clocksource = {

        .name   = "bcm1250-counter-3",

        .rating = 200,

        .read   = sb1250_hpt_read,

        .mask   = CLOCKSOURCE_MASK(23),

        .flags  = CLOCK_SOURCE_IS_CONTINUOUS,

};

void __init sb1250_clocksource_init(void)

{

        struct clocksource *cs = &bcm1250_clocksource;

        /* Setup hpt using timer #3 but do not enable irq for it */

        __raw_writeq(0,

                     IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM,

                                                 R_SCD_TIMER_CFG)));

        __raw_writeq(SB1250_HPT_VALUE,

                     IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM,

                                                 R_SCD_TIMER_INIT)));

        __raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,

                     IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM,

                                                 R_SCD_TIMER_CFG)));

        clocksource_set_clock(cs, V_SCD_TIMER_FREQ);

        clocksource_register(cs);

}