diff options
Diffstat (limited to 'drivers/clocksource/mips-gic-timer.c')
-rw-r--r-- | drivers/clocksource/mips-gic-timer.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c index 0bf28e6aca7a..3cf5912c4054 100644 --- a/drivers/clocksource/mips-gic-timer.c +++ b/drivers/clocksource/mips-gic-timer.c @@ -5,10 +5,100 @@ * * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. */ +#include <linux/clockchips.h> #include <linux/init.h> +#include <linux/interrupt.h> #include <linux/irqchip/mips-gic.h> +#include <linux/percpu.h> +#include <linux/smp.h> #include <linux/time.h> +#include <asm/time.h> + +DEFINE_PER_CPU(struct clock_event_device, gic_clockevent_device); +int gic_timer_irq_installed; + +static int gic_next_event(unsigned long delta, struct clock_event_device *evt) +{ + u64 cnt; + int res; + + cnt = gic_read_count(); + cnt += (u64)delta; + gic_write_cpu_compare(cnt, cpumask_first(evt->cpumask)); + res = ((int)(gic_read_count() - cnt) >= 0) ? -ETIME : 0; + return res; +} + +void gic_set_clock_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + /* Nothing to do ... */ +} + +irqreturn_t gic_compare_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *cd; + int cpu = smp_processor_id(); + + gic_write_compare(gic_read_compare()); + cd = &per_cpu(gic_clockevent_device, cpu); + cd->event_handler(cd); + return IRQ_HANDLED; +} + +struct irqaction gic_compare_irqaction = { + .handler = gic_compare_interrupt, + .flags = IRQF_PERCPU | IRQF_TIMER, + .name = "timer", +}; + +void gic_event_handler(struct clock_event_device *dev) +{ +} + +int gic_clockevent_init(void) +{ + unsigned int cpu = smp_processor_id(); + struct clock_event_device *cd; + unsigned int irq; + + if (!cpu_has_counter || !gic_frequency) + return -ENXIO; + + irq = MIPS_GIC_IRQ_BASE + GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE); + + cd = &per_cpu(gic_clockevent_device, cpu); + + cd->name = "MIPS GIC"; + cd->features = CLOCK_EVT_FEAT_ONESHOT | + CLOCK_EVT_FEAT_C3STOP; + + clockevent_set_clock(cd, gic_frequency); + + /* Calculate the min / max delta */ + cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd); + cd->min_delta_ns = clockevent_delta2ns(0x300, cd); + + cd->rating = 300; + cd->irq = irq; + cd->cpumask = cpumask_of(cpu); + cd->set_next_event = gic_next_event; + cd->set_mode = gic_set_clock_mode; + cd->event_handler = gic_event_handler; + + clockevents_register_device(cd); + + if (!gic_timer_irq_installed) { + setup_percpu_irq(irq, &gic_compare_irqaction); + gic_timer_irq_installed = 1; + } + + enable_percpu_irq(irq, IRQ_TYPE_NONE); + + return 0; +} + static cycle_t gic_hpt_read(struct clocksource *cs) { return gic_read_count(); |