diff options
Diffstat (limited to 'kernel/arch/mips/jz4740/time.c')
| -rw-r--r-- | kernel/arch/mips/jz4740/time.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/kernel/arch/mips/jz4740/time.c b/kernel/arch/mips/jz4740/time.c new file mode 100644 index 000000000..72b0cecbc --- /dev/null +++ b/kernel/arch/mips/jz4740/time.c @@ -0,0 +1,151 @@ +/* + * 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 <linux/sched_clock.h> + +#include <asm/mach-jz4740/irq.h> +#include <asm/mach-jz4740/timer.h> +#include <asm/time.h> + +#include "clock.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 u64 notrace jz4740_read_sched_clock(void) +{ + return jz4740_timer_get_count(TIMER_CLOCKSOURCE); +} + +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); + + sched_clock_register(jz4740_read_sched_clock, 16, clk_rate); + + 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); +} |