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/*
* 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.
*/
#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 inline cycle_t sb1250_hpt_get_cycles(void)
{
unsigned int count;
void __iomem *addr;
addr = IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CNT));
count = G_SCD_TIMER_CNT(__raw_readq(addr));
return SB1250_HPT_VALUE - count;
}
static cycle_t sb1250_hpt_read(struct clocksource *cs)
{
return sb1250_hpt_get_cycles();
}
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_register_hz(cs, V_SCD_TIMER_FREQ);
}
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