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-rw-r--r--arch/arm/mach-iop32x/time.c183
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/arm/mach-iop32x/time.c b/arch/arm/mach-iop32x/time.c
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+++ b/arch/arm/mach-iop32x/time.c
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * arch/arm/plat-iop/time.c
+ *
+ * Timer code for IOP32x and IOP33x based systems
+ *
+ * Author: Deepak Saxena <dsaxena@mvista.com>
+ *
+ * Copyright 2002-2003 MontaVista Software Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/timex.h>
+#include <linux/io.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/export.h>
+#include <linux/sched_clock.h>
+#include <asm/irq.h>
+#include <linux/uaccess.h>
+#include <asm/mach/irq.h>
+#include <asm/mach/time.h>
+
+#include "hardware.h"
+#include "irqs.h"
+
+/*
+ * Minimum clocksource/clockevent timer range in seconds
+ */
+#define IOP_MIN_RANGE 4
+
+/*
+ * IOP clocksource (free-running timer 1).
+ */
+static u64 notrace iop_clocksource_read(struct clocksource *unused)
+{
+ return 0xffffffffu - read_tcr1();
+}
+
+static struct clocksource iop_clocksource = {
+ .name = "iop_timer1",
+ .rating = 300,
+ .read = iop_clocksource_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/*
+ * IOP sched_clock() implementation via its clocksource.
+ */
+static u64 notrace iop_read_sched_clock(void)
+{
+ return 0xffffffffu - read_tcr1();
+}
+
+/*
+ * IOP clockevents (interrupting timer 0).
+ */
+static int iop_set_next_event(unsigned long delta,
+ struct clock_event_device *unused)
+{
+ u32 tmr = IOP_TMR_PRIVILEGED | IOP_TMR_RATIO_1_1;
+
+ BUG_ON(delta == 0);
+ write_tmr0(tmr & ~(IOP_TMR_EN | IOP_TMR_RELOAD));
+ write_tcr0(delta);
+ write_tmr0((tmr & ~IOP_TMR_RELOAD) | IOP_TMR_EN);
+
+ return 0;
+}
+
+static unsigned long ticks_per_jiffy;
+
+static int iop_set_periodic(struct clock_event_device *evt)
+{
+ u32 tmr = read_tmr0();
+
+ write_tmr0(tmr & ~IOP_TMR_EN);
+ write_tcr0(ticks_per_jiffy - 1);
+ write_trr0(ticks_per_jiffy - 1);
+ tmr |= (IOP_TMR_RELOAD | IOP_TMR_EN);
+
+ write_tmr0(tmr);
+ return 0;
+}
+
+static int iop_set_oneshot(struct clock_event_device *evt)
+{
+ u32 tmr = read_tmr0();
+
+ /* ->set_next_event sets period and enables timer */
+ tmr &= ~(IOP_TMR_RELOAD | IOP_TMR_EN);
+ write_tmr0(tmr);
+ return 0;
+}
+
+static int iop_shutdown(struct clock_event_device *evt)
+{
+ u32 tmr = read_tmr0();
+
+ tmr &= ~IOP_TMR_EN;
+ write_tmr0(tmr);
+ return 0;
+}
+
+static int iop_resume(struct clock_event_device *evt)
+{
+ u32 tmr = read_tmr0();
+
+ tmr |= IOP_TMR_EN;
+ write_tmr0(tmr);
+ return 0;
+}
+
+static struct clock_event_device iop_clockevent = {
+ .name = "iop_timer0",
+ .features = CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 300,
+ .set_next_event = iop_set_next_event,
+ .set_state_shutdown = iop_shutdown,
+ .set_state_periodic = iop_set_periodic,
+ .tick_resume = iop_resume,
+ .set_state_oneshot = iop_set_oneshot,
+};
+
+static irqreturn_t
+iop_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+
+ write_tisr(1);
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction iop_timer_irq = {
+ .name = "IOP Timer Tick",
+ .handler = iop_timer_interrupt,
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .dev_id = &iop_clockevent,
+};
+
+static unsigned long iop_tick_rate;
+unsigned long get_iop_tick_rate(void)
+{
+ return iop_tick_rate;
+}
+EXPORT_SYMBOL(get_iop_tick_rate);
+
+void __init iop_init_time(unsigned long tick_rate)
+{
+ u32 timer_ctl;
+
+ sched_clock_register(iop_read_sched_clock, 32, tick_rate);
+
+ ticks_per_jiffy = DIV_ROUND_CLOSEST(tick_rate, HZ);
+ iop_tick_rate = tick_rate;
+
+ timer_ctl = IOP_TMR_EN | IOP_TMR_PRIVILEGED |
+ IOP_TMR_RELOAD | IOP_TMR_RATIO_1_1;
+
+ /*
+ * Set up interrupting clockevent timer 0.
+ */
+ write_tmr0(timer_ctl & ~IOP_TMR_EN);
+ write_tisr(1);
+ setup_irq(IRQ_IOP32X_TIMER0, &iop_timer_irq);
+ iop_clockevent.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&iop_clockevent, tick_rate,
+ 0xf, 0xfffffffe);
+
+ /*
+ * Set up free-running clocksource timer 1.
+ */
+ write_trr1(0xffffffff);
+ write_tcr1(0xffffffff);
+ write_tmr1(timer_ctl);
+ clocksource_register_hz(&iop_clocksource, tick_rate);
+}