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1da177e4 LT |
1 | /* 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 | ||
1da177e4 LT |
13 | #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> | |
1da177e4 LT |
28 | |
29 | #include <linux/timex.h> | |
30 | ||
31 | #define TICK_SIZE (tick_nsec / 1000) | |
32 | ||
1da177e4 LT |
33 | unsigned long __nongprelbss __clkin_clock_speed_HZ; |
34 | unsigned long __nongprelbss __ext_bus_clock_speed_HZ; | |
35 | unsigned long __nongprelbss __res_bus_clock_speed_HZ; | |
36 | unsigned long __nongprelbss __sdram_clock_speed_HZ; | |
37 | unsigned long __nongprelbss __core_bus_clock_speed_HZ; | |
38 | unsigned long __nongprelbss __core_clock_speed_HZ; | |
39 | unsigned long __nongprelbss __dsu_clock_speed_HZ; | |
40 | unsigned long __nongprelbss __serial_clock_speed_HZ; | |
41 | unsigned long __delay_loops_MHz; | |
42 | ||
7d12e780 | 43 | static irqreturn_t timer_interrupt(int irq, void *dummy); |
1da177e4 LT |
44 | |
45 | static struct irqaction timer_irq = { | |
bc2e2635 | 46 | timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL |
1da177e4 LT |
47 | }; |
48 | ||
49 | static inline int set_rtc_mmss(unsigned long nowtime) | |
50 | { | |
51 | return -1; | |
52 | } | |
53 | ||
54 | /* | |
55 | * timer_interrupt() needs to keep up the real-time clock, | |
56 | * as well as call the "do_timer()" routine every clocktick | |
57 | */ | |
7d12e780 | 58 | static irqreturn_t timer_interrupt(int irq, void *dummy) |
1da177e4 LT |
59 | { |
60 | /* last time the cmos clock got updated */ | |
61 | static long last_rtc_update = 0; | |
62 | ||
63 | /* | |
64 | * Here we are in the timer irq handler. We just have irqs locally | |
65 | * disabled but we don't know if the timer_bh is running on the other | |
66 | * CPU. We need to avoid to SMP race with it. NOTE: we don' t need | |
67 | * the irq version of write_lock because as just said we have irq | |
68 | * locally disabled. -arca | |
69 | */ | |
70 | write_seqlock(&xtime_lock); | |
71 | ||
3171a030 | 72 | do_timer(1); |
7d12e780 DH |
73 | update_process_times(user_mode(get_irq_regs())); |
74 | profile_tick(CPU_PROFILING); | |
1da177e4 LT |
75 | |
76 | /* | |
77 | * If we have an externally synchronized Linux clock, then update | |
78 | * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be | |
79 | * called as close as possible to 500 ms before the new second starts. | |
80 | */ | |
b149ee22 | 81 | if (ntp_synced() && |
1da177e4 LT |
82 | xtime.tv_sec > last_rtc_update + 660 && |
83 | (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && | |
84 | (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2 | |
85 | ) { | |
86 | if (set_rtc_mmss(xtime.tv_sec) == 0) | |
87 | last_rtc_update = xtime.tv_sec; | |
88 | else | |
89 | last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ | |
90 | } | |
91 | ||
92 | #ifdef CONFIG_HEARTBEAT | |
93 | static unsigned short n; | |
94 | n++; | |
95 | __set_LEDS(n); | |
96 | #endif /* CONFIG_HEARTBEAT */ | |
97 | ||
98 | write_sequnlock(&xtime_lock); | |
99 | return IRQ_HANDLED; | |
100 | } | |
101 | ||
102 | void time_divisor_init(void) | |
103 | { | |
104 | unsigned short base, pre, prediv; | |
105 | ||
106 | /* set the scheduling timer going */ | |
107 | pre = 1; | |
108 | prediv = 4; | |
109 | base = __res_bus_clock_speed_HZ / pre / HZ / (1 << prediv); | |
110 | ||
111 | __set_TPRV(pre); | |
112 | __set_TxCKSL_DATA(0, prediv); | |
113 | __set_TCTR(TCTR_SC_CTR0 | TCTR_RL_RW_LH8 | TCTR_MODE_2); | |
114 | __set_TCSR_DATA(0, base & 0xff); | |
115 | __set_TCSR_DATA(0, base >> 8); | |
116 | } | |
117 | ||
118 | void time_init(void) | |
119 | { | |
120 | unsigned int year, mon, day, hour, min, sec; | |
121 | ||
122 | extern void arch_gettod(int *year, int *mon, int *day, int *hour, int *min, int *sec); | |
123 | ||
124 | /* FIX by dqg : Set to zero for platforms that don't have tod */ | |
125 | /* without this time is undefined and can overflow time_t, causing */ | |
126 | /* very stange errors */ | |
127 | year = 1980; | |
128 | mon = day = 1; | |
129 | hour = min = sec = 0; | |
130 | arch_gettod (&year, &mon, &day, &hour, &min, &sec); | |
131 | ||
132 | if ((year += 1900) < 1970) | |
133 | year += 100; | |
134 | xtime.tv_sec = mktime(year, mon, day, hour, min, sec); | |
135 | xtime.tv_nsec = 0; | |
136 | ||
137 | /* install scheduling interrupt handler */ | |
138 | setup_irq(IRQ_CPU_TIMER0, &timer_irq); | |
139 | ||
140 | time_divisor_init(); | |
141 | } | |
142 | ||
1da177e4 LT |
143 | /* |
144 | * Scheduler clock - returns current time in nanosec units. | |
145 | */ | |
146 | unsigned long long sched_clock(void) | |
147 | { | |
148 | return jiffies_64 * (1000000000 / HZ); | |
149 | } |