137 lines
3.2 KiB
C
137 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/arch/arm/mach-footbridge/dc21285-timer.c
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*
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* Copyright (C) 1998 Russell King.
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* Copyright (C) 1998 Phil Blundell
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*/
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#include <linux/clockchips.h>
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#include <linux/clocksource.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/sched_clock.h>
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#include <asm/irq.h>
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#include <asm/hardware/dec21285.h>
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#include <asm/mach/time.h>
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#include <asm/system_info.h>
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#include "common.h"
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static u64 cksrc_dc21285_read(struct clocksource *cs)
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{
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return cs->mask - *CSR_TIMER2_VALUE;
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}
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static int cksrc_dc21285_enable(struct clocksource *cs)
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{
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*CSR_TIMER2_LOAD = cs->mask;
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*CSR_TIMER2_CLR = 0;
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*CSR_TIMER2_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_DIV16;
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return 0;
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}
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static void cksrc_dc21285_disable(struct clocksource *cs)
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{
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*CSR_TIMER2_CNTL = 0;
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}
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static struct clocksource cksrc_dc21285 = {
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.name = "dc21285_timer2",
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.rating = 200,
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.read = cksrc_dc21285_read,
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.enable = cksrc_dc21285_enable,
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.disable = cksrc_dc21285_disable,
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.mask = CLOCKSOURCE_MASK(24),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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static int ckevt_dc21285_set_next_event(unsigned long delta,
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struct clock_event_device *c)
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{
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*CSR_TIMER1_CLR = 0;
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*CSR_TIMER1_LOAD = delta;
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*CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_DIV16;
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return 0;
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}
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static int ckevt_dc21285_shutdown(struct clock_event_device *c)
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{
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*CSR_TIMER1_CNTL = 0;
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return 0;
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}
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static int ckevt_dc21285_set_periodic(struct clock_event_device *c)
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{
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*CSR_TIMER1_CLR = 0;
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*CSR_TIMER1_LOAD = (mem_fclk_21285 + 8 * HZ) / (16 * HZ);
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*CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD |
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TIMER_CNTL_DIV16;
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return 0;
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}
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static struct clock_event_device ckevt_dc21285 = {
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.name = "dc21285_timer1",
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.features = CLOCK_EVT_FEAT_PERIODIC |
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CLOCK_EVT_FEAT_ONESHOT,
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.rating = 200,
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.irq = IRQ_TIMER1,
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.set_next_event = ckevt_dc21285_set_next_event,
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.set_state_shutdown = ckevt_dc21285_shutdown,
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.set_state_periodic = ckevt_dc21285_set_periodic,
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.set_state_oneshot = ckevt_dc21285_shutdown,
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.tick_resume = ckevt_dc21285_set_periodic,
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};
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static irqreturn_t timer1_interrupt(int irq, void *dev_id)
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{
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struct clock_event_device *ce = dev_id;
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*CSR_TIMER1_CLR = 0;
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/* Stop the timer if in one-shot mode */
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if (clockevent_state_oneshot(ce))
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*CSR_TIMER1_CNTL = 0;
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ce->event_handler(ce);
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return IRQ_HANDLED;
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}
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/*
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* Set up timer interrupt.
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*/
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void __init footbridge_timer_init(void)
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{
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struct clock_event_device *ce = &ckevt_dc21285;
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unsigned rate = DIV_ROUND_CLOSEST(mem_fclk_21285, 16);
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clocksource_register_hz(&cksrc_dc21285, rate);
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if (request_irq(ce->irq, timer1_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
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"dc21285_timer1", &ckevt_dc21285))
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pr_err("Failed to request irq %d (dc21285_timer1)", ce->irq);
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ce->cpumask = cpumask_of(smp_processor_id());
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clockevents_config_and_register(ce, rate, 0x4, 0xffffff);
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}
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static u64 notrace footbridge_read_sched_clock(void)
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{
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return ~*CSR_TIMER3_VALUE;
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}
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void __init footbridge_sched_clock(void)
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{
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unsigned rate = DIV_ROUND_CLOSEST(mem_fclk_21285, 16);
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*CSR_TIMER3_LOAD = 0;
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*CSR_TIMER3_CLR = 0;
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*CSR_TIMER3_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_DIV16;
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sched_clock_register(footbridge_read_sched_clock, 24, rate);
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}
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