72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2000, 2001 Broadcom Corporation
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*/
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#include <linux/clocksource.h>
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#include <linux/sched_clock.h>
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#include <asm/addrspace.h>
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#include <asm/io.h>
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#include <asm/time.h>
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#include <asm/sibyte/sb1250.h>
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#include <asm/sibyte/sb1250_regs.h>
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#include <asm/sibyte/sb1250_int.h>
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#include <asm/sibyte/sb1250_scd.h>
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#define SB1250_HPT_NUM 3
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#define SB1250_HPT_VALUE M_SCD_TIMER_CNT /* max value */
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/*
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* The HPT is free running from SB1250_HPT_VALUE down to 0 then starts over
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* again.
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*/
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static inline u64 sb1250_hpt_get_cycles(void)
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{
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unsigned int count;
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void __iomem *addr;
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addr = IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CNT));
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count = G_SCD_TIMER_CNT(__raw_readq(addr));
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return SB1250_HPT_VALUE - count;
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}
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static u64 sb1250_hpt_read(struct clocksource *cs)
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{
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return sb1250_hpt_get_cycles();
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}
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struct clocksource bcm1250_clocksource = {
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.name = "bcm1250-counter-3",
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.rating = 200,
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.read = sb1250_hpt_read,
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.mask = CLOCKSOURCE_MASK(23),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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static u64 notrace sb1250_read_sched_clock(void)
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{
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return sb1250_hpt_get_cycles();
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}
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void __init sb1250_clocksource_init(void)
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{
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struct clocksource *cs = &bcm1250_clocksource;
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/* Setup hpt using timer #3 but do not enable irq for it */
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__raw_writeq(0,
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IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM,
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R_SCD_TIMER_CFG)));
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__raw_writeq(SB1250_HPT_VALUE,
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IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM,
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R_SCD_TIMER_INIT)));
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__raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,
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IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM,
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R_SCD_TIMER_CFG)));
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clocksource_register_hz(cs, V_SCD_TIMER_FREQ);
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sched_clock_register(sb1250_read_sched_clock, 23, V_SCD_TIMER_FREQ);
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}
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