/* * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> * JZ4740 platform time support * * 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. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/time.h> #include <linux/clockchips.h> #include <asm/mach-jz4740/irq.h> #include <asm/time.h> #include "clock.h" #include "timer.h" #define TIMER_CLOCKEVENT 0 #define TIMER_CLOCKSOURCE 1 static uint16_t jz4740_jiffies_per_tick; static cycle_t jz4740_clocksource_read(struct clocksource *cs) { return jz4740_timer_get_count(TIMER_CLOCKSOURCE); } static struct clocksource jz4740_clocksource = { .name = "jz4740-timer", .rating = 200, .read = jz4740_clocksource_read, .mask = CLOCKSOURCE_MASK(16), .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static irqreturn_t jz4740_clockevent_irq(int irq, void *devid) { struct clock_event_device *cd = devid; jz4740_timer_ack_full(TIMER_CLOCKEVENT); if (cd->mode != CLOCK_EVT_MODE_PERIODIC) jz4740_timer_disable(TIMER_CLOCKEVENT); cd->event_handler(cd); return IRQ_HANDLED; } static void jz4740_clockevent_set_mode(enum clock_event_mode mode, struct clock_event_device *cd) { switch (mode) { case CLOCK_EVT_MODE_PERIODIC: jz4740_timer_set_count(TIMER_CLOCKEVENT, 0); jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick); case CLOCK_EVT_MODE_RESUME: jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT); jz4740_timer_enable(TIMER_CLOCKEVENT); break; case CLOCK_EVT_MODE_ONESHOT: case CLOCK_EVT_MODE_SHUTDOWN: jz4740_timer_disable(TIMER_CLOCKEVENT); break; default: break; } } static int jz4740_clockevent_set_next(unsigned long evt, struct clock_event_device *cd) { jz4740_timer_set_count(TIMER_CLOCKEVENT, 0); jz4740_timer_set_period(TIMER_CLOCKEVENT, evt); jz4740_timer_enable(TIMER_CLOCKEVENT); return 0; } static struct clock_event_device jz4740_clockevent = { .name = "jz4740-timer", .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, .set_next_event = jz4740_clockevent_set_next, .set_mode = jz4740_clockevent_set_mode, .rating = 200, .irq = JZ4740_IRQ_TCU0, }; static struct irqaction timer_irqaction = { .handler = jz4740_clockevent_irq, .flags = IRQF_PERCPU | IRQF_TIMER, .name = "jz4740-timerirq", .dev_id = &jz4740_clockevent, }; void __init plat_time_init(void) { int ret; uint32_t clk_rate; uint16_t ctrl; jz4740_timer_init(); clk_rate = jz4740_clock_bdata.ext_rate >> 4; jz4740_jiffies_per_tick = DIV_ROUND_CLOSEST(clk_rate, HZ); clockevent_set_clock(&jz4740_clockevent, clk_rate); jz4740_clockevent.min_delta_ns = clockevent_delta2ns(100, &jz4740_clockevent); jz4740_clockevent.max_delta_ns = clockevent_delta2ns(0xffff, &jz4740_clockevent); jz4740_clockevent.cpumask = cpumask_of(0); clockevents_register_device(&jz4740_clockevent); ret = clocksource_register_hz(&jz4740_clocksource, clk_rate); if (ret) printk(KERN_ERR "Failed to register clocksource: %d\n", ret); setup_irq(JZ4740_IRQ_TCU0, &timer_irqaction); ctrl = JZ_TIMER_CTRL_PRESCALE_16 | JZ_TIMER_CTRL_SRC_EXT; jz4740_timer_set_ctrl(TIMER_CLOCKEVENT, ctrl); jz4740_timer_set_ctrl(TIMER_CLOCKSOURCE, ctrl); jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick); jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT); jz4740_timer_set_period(TIMER_CLOCKSOURCE, 0xffff); jz4740_timer_enable(TIMER_CLOCKEVENT); jz4740_timer_enable(TIMER_CLOCKSOURCE); }