/* * * Copyright (C) 2015 Numascale AS. All rights reserved. * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * 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/clockchips.h> #include <asm/irq.h> #include <asm/numachip/numachip.h> #include <asm/numachip/numachip_csr.h> static DEFINE_PER_CPU(struct clock_event_device, numachip2_ced); static cycles_t numachip2_timer_read(struct clocksource *cs) { return numachip2_read64_lcsr(NUMACHIP2_TIMER_NOW); } static struct clocksource numachip2_clocksource = { .name = "numachip2", .rating = 295, .read = numachip2_timer_read, .mask = CLOCKSOURCE_MASK(64), .flags = CLOCK_SOURCE_IS_CONTINUOUS, .mult = 1, .shift = 0, }; static int numachip2_set_next_event(unsigned long delta, struct clock_event_device *ced) { numachip2_write64_lcsr(NUMACHIP2_TIMER_DEADLINE + numachip2_timer(), delta); return 0; } static const struct clock_event_device numachip2_clockevent __initconst = { .name = "numachip2", .rating = 400, .set_next_event = numachip2_set_next_event, .features = CLOCK_EVT_FEAT_ONESHOT, .mult = 1, .shift = 0, .min_delta_ns = 1250, .min_delta_ticks = 1250, .max_delta_ns = LONG_MAX, .max_delta_ticks = LONG_MAX, }; static void numachip_timer_interrupt(void) { struct clock_event_device *ced = this_cpu_ptr(&numachip2_ced); ced->event_handler(ced); } static __init void numachip_timer_each(struct work_struct *work) { unsigned local_apicid = __this_cpu_read(x86_cpu_to_apicid) & 0xff; struct clock_event_device *ced = this_cpu_ptr(&numachip2_ced); /* Setup IPI vector to local core and relative timing mode */ numachip2_write64_lcsr(NUMACHIP2_TIMER_INT + numachip2_timer(), (3 << 22) | (X86_PLATFORM_IPI_VECTOR << 14) | (local_apicid << 6)); *ced = numachip2_clockevent; ced->cpumask = cpumask_of(smp_processor_id()); clockevents_register_device(ced); } static int __init numachip_timer_init(void) { if (numachip_system != 2) return -ENODEV; /* Reset timer */ numachip2_write64_lcsr(NUMACHIP2_TIMER_RESET, 0); clocksource_register_hz(&numachip2_clocksource, NSEC_PER_SEC); /* Setup per-cpu clockevents */ x86_platform_ipi_callback = numachip_timer_interrupt; schedule_on_each_cpu(&numachip_timer_each); return 0; } arch_initcall(numachip_timer_init);