98 lines
2.7 KiB
C
98 lines
2.7 KiB
C
/*
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*
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* Copyright (C) 2015 Numascale AS. All rights reserved.
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/clockchips.h>
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#include <asm/irq.h>
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#include <asm/numachip/numachip.h>
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#include <asm/numachip/numachip_csr.h>
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static DEFINE_PER_CPU(struct clock_event_device, numachip2_ced);
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static cycles_t numachip2_timer_read(struct clocksource *cs)
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{
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return numachip2_read64_lcsr(NUMACHIP2_TIMER_NOW);
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}
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static struct clocksource numachip2_clocksource = {
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.name = "numachip2",
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.rating = 295,
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.read = numachip2_timer_read,
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.mask = CLOCKSOURCE_MASK(64),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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.mult = 1,
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.shift = 0,
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};
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static int numachip2_set_next_event(unsigned long delta, struct clock_event_device *ced)
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{
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numachip2_write64_lcsr(NUMACHIP2_TIMER_DEADLINE + numachip2_timer(),
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delta);
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return 0;
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}
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static const struct clock_event_device numachip2_clockevent __initconst = {
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.name = "numachip2",
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.rating = 400,
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.set_next_event = numachip2_set_next_event,
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.features = CLOCK_EVT_FEAT_ONESHOT,
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.mult = 1,
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.shift = 0,
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.min_delta_ns = 1250,
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.min_delta_ticks = 1250,
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.max_delta_ns = LONG_MAX,
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.max_delta_ticks = LONG_MAX,
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};
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static void numachip_timer_interrupt(void)
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{
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struct clock_event_device *ced = this_cpu_ptr(&numachip2_ced);
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ced->event_handler(ced);
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}
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static __init void numachip_timer_each(struct work_struct *work)
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{
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unsigned local_apicid = __this_cpu_read(x86_cpu_to_apicid) & 0xff;
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struct clock_event_device *ced = this_cpu_ptr(&numachip2_ced);
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/* Setup IPI vector to local core and relative timing mode */
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numachip2_write64_lcsr(NUMACHIP2_TIMER_INT + numachip2_timer(),
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(3 << 22) | (X86_PLATFORM_IPI_VECTOR << 14) |
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(local_apicid << 6));
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*ced = numachip2_clockevent;
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ced->cpumask = cpumask_of(smp_processor_id());
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clockevents_register_device(ced);
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}
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static int __init numachip_timer_init(void)
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{
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if (numachip_system != 2)
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return -ENODEV;
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/* Reset timer */
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numachip2_write64_lcsr(NUMACHIP2_TIMER_RESET, 0);
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clocksource_register_hz(&numachip2_clocksource, NSEC_PER_SEC);
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/* Setup per-cpu clockevents */
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x86_platform_ipi_callback = numachip_timer_interrupt;
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schedule_on_each_cpu(&numachip_timer_each);
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return 0;
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}
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arch_initcall(numachip_timer_init);
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