2 * arch/arm/plat-iop/time.c
4 * Timer code for IOP32x and IOP33x based systems
6 * Author: Deepak Saxena <dsaxena@mvista.com>
8 * Copyright 2002-2003 MontaVista Software Inc.
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
16 #include <linux/kernel.h>
17 #include <linux/interrupt.h>
18 #include <linux/time.h>
19 #include <linux/init.h>
20 #include <linux/timex.h>
21 #include <linux/sched.h>
23 #include <linux/clocksource.h>
24 #include <linux/clockchips.h>
25 #include <mach/hardware.h>
27 #include <asm/uaccess.h>
28 #include <asm/mach/irq.h>
29 #include <asm/mach/time.h>
30 #include <mach/time.h>
33 * Minimum clocksource/clockevent timer range in seconds
35 #define IOP_MIN_RANGE 4
38 * IOP clocksource (free-running timer 1).
40 static cycle_t notrace iop_clocksource_read(struct clocksource *unused)
42 return 0xffffffffu - read_tcr1();
45 static struct clocksource iop_clocksource = {
48 .read = iop_clocksource_read,
49 .mask = CLOCKSOURCE_MASK(32),
50 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
54 * IOP sched_clock() implementation via its clocksource.
56 unsigned long long sched_clock(void)
58 cycle_t cyc = iop_clocksource_read(NULL);
59 struct clocksource *cs = &iop_clocksource;
61 return clocksource_cyc2ns(cyc, cs->mult, cs->shift);
65 * IOP clockevents (interrupting timer 0).
67 static int iop_set_next_event(unsigned long delta,
68 struct clock_event_device *unused)
70 u32 tmr = IOP_TMR_PRIVILEGED | IOP_TMR_RATIO_1_1;
73 write_tmr0(tmr & ~(IOP_TMR_EN | IOP_TMR_RELOAD));
75 write_tmr0((tmr & ~IOP_TMR_RELOAD) | IOP_TMR_EN);
80 static unsigned long ticks_per_jiffy;
82 static void iop_set_mode(enum clock_event_mode mode,
83 struct clock_event_device *unused)
85 u32 tmr = read_tmr0();
88 case CLOCK_EVT_MODE_PERIODIC:
89 write_tmr0(tmr & ~IOP_TMR_EN);
90 write_tcr0(ticks_per_jiffy - 1);
91 tmr |= (IOP_TMR_RELOAD | IOP_TMR_EN);
93 case CLOCK_EVT_MODE_ONESHOT:
94 /* ->set_next_event sets period and enables timer */
95 tmr &= ~(IOP_TMR_RELOAD | IOP_TMR_EN);
97 case CLOCK_EVT_MODE_RESUME:
100 case CLOCK_EVT_MODE_SHUTDOWN:
101 case CLOCK_EVT_MODE_UNUSED:
110 static struct clock_event_device iop_clockevent = {
111 .name = "iop_timer0",
112 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
114 .set_next_event = iop_set_next_event,
115 .set_mode = iop_set_mode,
119 iop_timer_interrupt(int irq, void *dev_id)
121 struct clock_event_device *evt = dev_id;
124 evt->event_handler(evt);
128 static struct irqaction iop_timer_irq = {
129 .name = "IOP Timer Tick",
130 .handler = iop_timer_interrupt,
131 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
132 .dev_id = &iop_clockevent,
135 static unsigned long iop_tick_rate;
136 unsigned long get_iop_tick_rate(void)
138 return iop_tick_rate;
140 EXPORT_SYMBOL(get_iop_tick_rate);
142 void __init iop_init_time(unsigned long tick_rate)
146 ticks_per_jiffy = DIV_ROUND_CLOSEST(tick_rate, HZ);
147 iop_tick_rate = tick_rate;
149 timer_ctl = IOP_TMR_EN | IOP_TMR_PRIVILEGED |
150 IOP_TMR_RELOAD | IOP_TMR_RATIO_1_1;
153 * Set up interrupting clockevent timer 0.
155 write_tmr0(timer_ctl & ~IOP_TMR_EN);
156 setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq);
157 clockevents_calc_mult_shift(&iop_clockevent,
158 tick_rate, IOP_MIN_RANGE);
159 iop_clockevent.max_delta_ns =
160 clockevent_delta2ns(0xfffffffe, &iop_clockevent);
161 iop_clockevent.min_delta_ns =
162 clockevent_delta2ns(0xf, &iop_clockevent);
163 iop_clockevent.cpumask = cpumask_of(0);
164 clockevents_register_device(&iop_clockevent);
165 write_trr0(ticks_per_jiffy - 1);
166 write_tcr0(ticks_per_jiffy - 1);
167 write_tmr0(timer_ctl);
170 * Set up free-running clocksource timer 1.
172 write_trr1(0xffffffff);
173 write_tcr1(0xffffffff);
174 write_tmr1(timer_ctl);
175 clocksource_calc_mult_shift(&iop_clocksource, tick_rate,
177 clocksource_register(&iop_clocksource);