![Raghu Gandham](/assets/img/avatar_default.png)
Add new clockevent driver that uses the counter present on the MIPS Global Interrupt Controller. Signed-off-by: Raghu Gandham <Raghu.Gandham@imgtec.com> Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
105 lines
2.4 KiB
C
105 lines
2.4 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2013 Imagination Technologies Ltd.
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*/
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#include <linux/clockchips.h>
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#include <linux/interrupt.h>
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#include <linux/percpu.h>
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#include <linux/smp.h>
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#include <linux/irq.h>
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#include <asm/time.h>
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#include <asm/gic.h>
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#include <asm/mips-boards/maltaint.h>
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DEFINE_PER_CPU(struct clock_event_device, gic_clockevent_device);
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int gic_timer_irq_installed;
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static int gic_next_event(unsigned long delta, struct clock_event_device *evt)
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{
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u64 cnt;
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int res;
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cnt = gic_read_count();
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cnt += (u64)delta;
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gic_write_compare(cnt);
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res = ((int)(gic_read_count() - cnt) >= 0) ? -ETIME : 0;
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return res;
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}
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void gic_set_clock_mode(enum clock_event_mode mode,
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struct clock_event_device *evt)
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{
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/* Nothing to do ... */
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}
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irqreturn_t gic_compare_interrupt(int irq, void *dev_id)
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{
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struct clock_event_device *cd;
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int cpu = smp_processor_id();
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gic_write_compare(gic_read_compare());
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cd = &per_cpu(gic_clockevent_device, cpu);
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cd->event_handler(cd);
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return IRQ_HANDLED;
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}
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struct irqaction gic_compare_irqaction = {
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.handler = gic_compare_interrupt,
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.flags = IRQF_PERCPU | IRQF_TIMER,
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.name = "timer",
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};
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void gic_event_handler(struct clock_event_device *dev)
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{
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}
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int __cpuinit gic_clockevent_init(void)
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{
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unsigned int cpu = smp_processor_id();
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struct clock_event_device *cd;
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unsigned int irq;
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if (!cpu_has_counter || !gic_frequency)
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return -ENXIO;
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irq = MIPS_GIC_IRQ_BASE;
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cd = &per_cpu(gic_clockevent_device, cpu);
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cd->name = "MIPS GIC";
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cd->features = CLOCK_EVT_FEAT_ONESHOT;
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clockevent_set_clock(cd, gic_frequency);
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/* Calculate the min / max delta */
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cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
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cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
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cd->rating = 300;
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cd->irq = irq;
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cd->cpumask = cpumask_of(cpu);
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cd->set_next_event = gic_next_event;
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cd->set_mode = gic_set_clock_mode;
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cd->event_handler = gic_event_handler;
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clockevents_register_device(cd);
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GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_MAP), 0x80000002);
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GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_SMASK), GIC_VPE_SMASK_CMP_MSK);
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if (gic_timer_irq_installed)
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return 0;
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gic_timer_irq_installed = 1;
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setup_irq(irq, &gic_compare_irqaction);
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irq_set_handler(irq, handle_percpu_irq);
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return 0;
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}
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