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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* time.c: FRV arch-specific time handling
2 *
3 * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * - Derived from arch/m68k/kernel/time.c
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/module.h>
14#include <linux/errno.h>
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/param.h>
18#include <linux/string.h>
19#include <linux/interrupt.h>
20#include <linux/profile.h>
21#include <linux/irq.h>
22#include <linux/mm.h>
23
24#include <asm/io.h>
25#include <asm/timer-regs.h>
26#include <asm/mb-regs.h>
27#include <asm/mb86943a.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
29#include <linux/timex.h>
30
31#define TICK_SIZE (tick_nsec / 1000)
32
Linus Torvalds1da177e2005-04-16 15:20:36 -070033unsigned long __nongprelbss __clkin_clock_speed_HZ;
34unsigned long __nongprelbss __ext_bus_clock_speed_HZ;
35unsigned long __nongprelbss __res_bus_clock_speed_HZ;
36unsigned long __nongprelbss __sdram_clock_speed_HZ;
37unsigned long __nongprelbss __core_bus_clock_speed_HZ;
38unsigned long __nongprelbss __core_clock_speed_HZ;
39unsigned long __nongprelbss __dsu_clock_speed_HZ;
40unsigned long __nongprelbss __serial_clock_speed_HZ;
41unsigned long __delay_loops_MHz;
42
David Howells7d12e782006-10-05 14:55:46 +010043static irqreturn_t timer_interrupt(int irq, void *dummy);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
45static struct irqaction timer_irq = {
Thomas Gleixnera2e170e2007-10-16 01:26:29 -070046 .handler = timer_interrupt,
47 .flags = IRQF_DISABLED,
Thomas Gleixnera2e170e2007-10-16 01:26:29 -070048 .name = "timer",
Linus Torvalds1da177e2005-04-16 15:20:36 -070049};
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051/*
52 * timer_interrupt() needs to keep up the real-time clock,
53 * as well as call the "do_timer()" routine every clocktick
54 */
David Howells7d12e782006-10-05 14:55:46 +010055static irqreturn_t timer_interrupt(int irq, void *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -070056{
Peter Zijlstraaa02cd22008-02-13 21:33:16 +010057 profile_tick(CPU_PROFILING);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 /*
59 * Here we are in the timer irq handler. We just have irqs locally
60 * disabled but we don't know if the timer_bh is running on the other
Simon Arlott761a7e32007-10-20 01:09:42 +020061 * CPU. We need to avoid to SMP race with it. NOTE: we don't need
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 * the irq version of write_lock because as just said we have irq
63 * locally disabled. -arca
64 */
65 write_seqlock(&xtime_lock);
66
Atsushi Nemoto3171a032006-09-29 02:00:32 -070067 do_timer(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Linus Torvalds1da177e2005-04-16 15:20:36 -070069#ifdef CONFIG_HEARTBEAT
70 static unsigned short n;
71 n++;
72 __set_LEDS(n);
73#endif /* CONFIG_HEARTBEAT */
74
75 write_sequnlock(&xtime_lock);
Peter Zijlstraaa02cd22008-02-13 21:33:16 +010076
77 update_process_times(user_mode(get_irq_regs()));
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 return IRQ_HANDLED;
80}
81
82void time_divisor_init(void)
83{
84 unsigned short base, pre, prediv;
85
86 /* set the scheduling timer going */
87 pre = 1;
88 prediv = 4;
89 base = __res_bus_clock_speed_HZ / pre / HZ / (1 << prediv);
90
91 __set_TPRV(pre);
92 __set_TxCKSL_DATA(0, prediv);
93 __set_TCTR(TCTR_SC_CTR0 | TCTR_RL_RW_LH8 | TCTR_MODE_2);
94 __set_TCSR_DATA(0, base & 0xff);
95 __set_TCSR_DATA(0, base >> 8);
96}
97
John Stultz739b2712010-03-03 19:57:18 -080098
99void read_persistent_clock(struct timespec *ts)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100{
101 unsigned int year, mon, day, hour, min, sec;
102
103 extern void arch_gettod(int *year, int *mon, int *day, int *hour, int *min, int *sec);
104
105 /* FIX by dqg : Set to zero for platforms that don't have tod */
106 /* without this time is undefined and can overflow time_t, causing */
Simon Arlott761a7e32007-10-20 01:09:42 +0200107 /* very strange errors */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 year = 1980;
109 mon = day = 1;
110 hour = min = sec = 0;
111 arch_gettod (&year, &mon, &day, &hour, &min, &sec);
112
113 if ((year += 1900) < 1970)
114 year += 100;
John Stultz739b2712010-03-03 19:57:18 -0800115 ts->tv_sec = mktime(year, mon, day, hour, min, sec);
116 ts->tv_nsec = 0;
117}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
John Stultz739b2712010-03-03 19:57:18 -0800119void time_init(void)
120{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 /* install scheduling interrupt handler */
122 setup_irq(IRQ_CPU_TIMER0, &timer_irq);
123
124 time_divisor_init();
125}
126
127/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 * Scheduler clock - returns current time in nanosec units.
129 */
130unsigned long long sched_clock(void)
131{
132 return jiffies_64 * (1000000000 / HZ);
133}