1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
4 * JZ4740 platform time support
8 #include <linux/clk-provider.h>
9 #include <linux/interrupt.h>
10 #include <linux/kernel.h>
11 #include <linux/time.h>
13 #include <linux/clockchips.h>
14 #include <linux/sched_clock.h>
16 #include <asm/mach-jz4740/irq.h>
17 #include <asm/mach-jz4740/timer.h>
20 #define TIMER_CLOCKEVENT 0
21 #define TIMER_CLOCKSOURCE 1
23 static uint16_t jz4740_jiffies_per_tick;
25 static u64 jz4740_clocksource_read(struct clocksource *cs)
27 return jz4740_timer_get_count(TIMER_CLOCKSOURCE);
30 static struct clocksource jz4740_clocksource = {
31 .name = "jz4740-timer",
33 .read = jz4740_clocksource_read,
34 .mask = CLOCKSOURCE_MASK(16),
35 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
38 static u64 notrace jz4740_read_sched_clock(void)
40 return jz4740_timer_get_count(TIMER_CLOCKSOURCE);
43 static irqreturn_t jz4740_clockevent_irq(int irq, void *devid)
45 struct clock_event_device *cd = devid;
47 jz4740_timer_ack_full(TIMER_CLOCKEVENT);
49 if (!clockevent_state_periodic(cd))
50 jz4740_timer_disable(TIMER_CLOCKEVENT);
52 cd->event_handler(cd);
57 static int jz4740_clockevent_set_periodic(struct clock_event_device *evt)
59 jz4740_timer_set_count(TIMER_CLOCKEVENT, 0);
60 jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick);
61 jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
62 jz4740_timer_enable(TIMER_CLOCKEVENT);
67 static int jz4740_clockevent_resume(struct clock_event_device *evt)
69 jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
70 jz4740_timer_enable(TIMER_CLOCKEVENT);
75 static int jz4740_clockevent_shutdown(struct clock_event_device *evt)
77 jz4740_timer_disable(TIMER_CLOCKEVENT);
82 static int jz4740_clockevent_set_next(unsigned long evt,
83 struct clock_event_device *cd)
85 jz4740_timer_set_count(TIMER_CLOCKEVENT, 0);
86 jz4740_timer_set_period(TIMER_CLOCKEVENT, evt);
87 jz4740_timer_enable(TIMER_CLOCKEVENT);
92 static struct clock_event_device jz4740_clockevent = {
93 .name = "jz4740-timer",
94 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
95 .set_next_event = jz4740_clockevent_set_next,
96 .set_state_shutdown = jz4740_clockevent_shutdown,
97 .set_state_periodic = jz4740_clockevent_set_periodic,
98 .set_state_oneshot = jz4740_clockevent_shutdown,
99 .tick_resume = jz4740_clockevent_resume,
101 #ifdef CONFIG_MACH_JZ4740
102 .irq = JZ4740_IRQ_TCU0,
104 #if defined(CONFIG_MACH_JZ4770) || defined(CONFIG_MACH_JZ4780)
105 .irq = JZ4780_IRQ_TCU2,
109 static struct irqaction timer_irqaction = {
110 .handler = jz4740_clockevent_irq,
111 .flags = IRQF_PERCPU | IRQF_TIMER,
112 .name = "jz4740-timerirq",
113 .dev_id = &jz4740_clockevent,
116 void __init plat_time_init(void)
126 ext_clk = clk_get(NULL, "ext");
128 panic("unable to get ext clock");
129 clk_rate = clk_get_rate(ext_clk) >> 4;
132 jz4740_jiffies_per_tick = DIV_ROUND_CLOSEST(clk_rate, HZ);
134 clockevent_set_clock(&jz4740_clockevent, clk_rate);
135 jz4740_clockevent.min_delta_ns = clockevent_delta2ns(100, &jz4740_clockevent);
136 jz4740_clockevent.min_delta_ticks = 100;
137 jz4740_clockevent.max_delta_ns = clockevent_delta2ns(0xffff, &jz4740_clockevent);
138 jz4740_clockevent.max_delta_ticks = 0xffff;
139 jz4740_clockevent.cpumask = cpumask_of(0);
141 clockevents_register_device(&jz4740_clockevent);
143 ret = clocksource_register_hz(&jz4740_clocksource, clk_rate);
146 printk(KERN_ERR "Failed to register clocksource: %d\n", ret);
148 sched_clock_register(jz4740_read_sched_clock, 16, clk_rate);
150 setup_irq(jz4740_clockevent.irq, &timer_irqaction);
152 ctrl = JZ_TIMER_CTRL_PRESCALE_16 | JZ_TIMER_CTRL_SRC_EXT;
154 jz4740_timer_set_ctrl(TIMER_CLOCKEVENT, ctrl);
155 jz4740_timer_set_ctrl(TIMER_CLOCKSOURCE, ctrl);
157 jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick);
158 jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
160 jz4740_timer_set_period(TIMER_CLOCKSOURCE, 0xffff);
162 jz4740_timer_enable(TIMER_CLOCKEVENT);
163 jz4740_timer_enable(TIMER_CLOCKSOURCE);