/* * arch/score/kernel/time.c * * Score Processor version. * * Copyright (C) 2009 Sunplus Core Technology Co., Ltd. * Chen Liqin <liqin.chen@sunplusct.com> * Lennox Wu <lennox.wu@sunplusct.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, see the file COPYING, or write * to the Free Software Foundation, Inc., * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include <linux/clockchips.h> #include <linux/interrupt.h> #include <asm/scoreregs.h> static irqreturn_t timer_interrupt(int irq, void *dev_id) { struct clock_event_device *evdev = dev_id; /* clear timer interrupt flag */ outl(1, P_TIMER0_CPP_REG); evdev->event_handler(evdev); return IRQ_HANDLED; } static struct irqaction timer_irq = { .handler = timer_interrupt, .flags = IRQF_DISABLED | IRQF_TIMER, .name = "timer", }; static int score_timer_set_next_event(unsigned long delta, struct clock_event_device *evdev) { outl((TMR_M_PERIODIC | TMR_IE_ENABLE), P_TIMER0_CTRL); outl(delta, P_TIMER0_PRELOAD); outl(inl(P_TIMER0_CTRL) | TMR_ENABLE, P_TIMER0_CTRL); return 0; } static void score_timer_set_mode(enum clock_event_mode mode, struct clock_event_device *evdev) { switch (mode) { case CLOCK_EVT_MODE_PERIODIC: outl((TMR_M_PERIODIC | TMR_IE_ENABLE), P_TIMER0_CTRL); outl(SYSTEM_CLOCK/HZ, P_TIMER0_PRELOAD); outl(inl(P_TIMER0_CTRL) | TMR_ENABLE, P_TIMER0_CTRL); break; case CLOCK_EVT_MODE_ONESHOT: case CLOCK_EVT_MODE_SHUTDOWN: case CLOCK_EVT_MODE_RESUME: case CLOCK_EVT_MODE_UNUSED: break; default: BUG(); } } static struct clock_event_device score_clockevent = { .name = "score_clockevent", .features = CLOCK_EVT_FEAT_PERIODIC, .shift = 16, .set_next_event = score_timer_set_next_event, .set_mode = score_timer_set_mode, }; void __init time_init(void) { timer_irq.dev_id = &score_clockevent; setup_irq(IRQ_TIMER , &timer_irq); /* setup COMPARE clockevent */ score_clockevent.mult = div_sc(SYSTEM_CLOCK, NSEC_PER_SEC, score_clockevent.shift); score_clockevent.max_delta_ns = clockevent_delta2ns((u32)~0, &score_clockevent); score_clockevent.min_delta_ns = clockevent_delta2ns(50, &score_clockevent) + 1; score_clockevent.cpumask = cpumask_of(0); clockevents_register_device(&score_clockevent); }