1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ip30-timer.c: Clocksource/clockevent support for the 4 * HEART chip in SGI Octane (IP30) systems. 5 * 6 * Copyright (C) 2004-2007 Stanislaw Skowronek <skylark@unaligned.org> 7 * Copyright (C) 2009 Johannes Dickgreber <tanzy@gmx.de> 8 * Copyright (C) 2011 Joshua Kinard <kumba@gentoo.org> 9 */ 10 11 #include <linux/clocksource.h> 12 #include <linux/cpumask.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/percpu.h> 16 #include <linux/sched_clock.h> 17 18 #include <asm/time.h> 19 #include <asm/cevt-r4k.h> 20 #include <asm/sgi/heart.h> 21 22 static u64 ip30_heart_counter_read(struct clocksource *cs) 23 { 24 return heart_read(&heart_regs->count); 25 } 26 27 struct clocksource ip30_heart_clocksource = { 28 .name = "HEART", 29 .rating = 400, 30 .read = ip30_heart_counter_read, 31 .mask = CLOCKSOURCE_MASK(52), 32 .flags = (CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_VALID_FOR_HRES), 33 }; 34 35 static u64 notrace ip30_heart_read_sched_clock(void) 36 { 37 return heart_read(&heart_regs->count); 38 } 39 40 static void __init ip30_heart_clocksource_init(void) 41 { 42 struct clocksource *cs = &ip30_heart_clocksource; 43 44 clocksource_register_hz(cs, HEART_CYCLES_PER_SEC); 45 46 sched_clock_register(ip30_heart_read_sched_clock, 52, 47 HEART_CYCLES_PER_SEC); 48 } 49 50 void __init plat_time_init(void) 51 { 52 int irq = get_c0_compare_int(); 53 54 cp0_timer_irq_installed = 1; 55 c0_compare_irqaction.percpu_dev_id = &mips_clockevent_device; 56 c0_compare_irqaction.flags &= ~IRQF_SHARED; 57 irq_set_handler(irq, handle_percpu_devid_irq); 58 irq_set_percpu_devid(irq); 59 setup_percpu_irq(irq, &c0_compare_irqaction); 60 enable_percpu_irq(irq, IRQ_TYPE_NONE); 61 62 ip30_heart_clocksource_init(); 63 } 64