diff options
Diffstat (limited to 'arch/frv/kernel/time.c')
-rw-r--r-- | arch/frv/kernel/time.c | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/arch/frv/kernel/time.c b/arch/frv/kernel/time.c new file mode 100644 index 000000000000..075db6644694 --- /dev/null +++ b/arch/frv/kernel/time.c | |||
@@ -0,0 +1,234 @@ | |||
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 | |||
13 | #include <linux/config.h> /* CONFIG_HEARTBEAT */ | ||
14 | #include <linux/module.h> | ||
15 | #include <linux/errno.h> | ||
16 | #include <linux/sched.h> | ||
17 | #include <linux/kernel.h> | ||
18 | #include <linux/param.h> | ||
19 | #include <linux/string.h> | ||
20 | #include <linux/interrupt.h> | ||
21 | #include <linux/profile.h> | ||
22 | #include <linux/irq.h> | ||
23 | #include <linux/mm.h> | ||
24 | |||
25 | #include <asm/io.h> | ||
26 | #include <asm/timer-regs.h> | ||
27 | #include <asm/mb-regs.h> | ||
28 | #include <asm/mb86943a.h> | ||
29 | #include <asm/irq-routing.h> | ||
30 | |||
31 | #include <linux/timex.h> | ||
32 | |||
33 | #define TICK_SIZE (tick_nsec / 1000) | ||
34 | |||
35 | extern unsigned long wall_jiffies; | ||
36 | |||
37 | u64 jiffies_64 = INITIAL_JIFFIES; | ||
38 | EXPORT_SYMBOL(jiffies_64); | ||
39 | |||
40 | unsigned long __nongprelbss __clkin_clock_speed_HZ; | ||
41 | unsigned long __nongprelbss __ext_bus_clock_speed_HZ; | ||
42 | unsigned long __nongprelbss __res_bus_clock_speed_HZ; | ||
43 | unsigned long __nongprelbss __sdram_clock_speed_HZ; | ||
44 | unsigned long __nongprelbss __core_bus_clock_speed_HZ; | ||
45 | unsigned long __nongprelbss __core_clock_speed_HZ; | ||
46 | unsigned long __nongprelbss __dsu_clock_speed_HZ; | ||
47 | unsigned long __nongprelbss __serial_clock_speed_HZ; | ||
48 | unsigned long __delay_loops_MHz; | ||
49 | |||
50 | static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs *regs); | ||
51 | |||
52 | static struct irqaction timer_irq = { | ||
53 | timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE, "timer", NULL, NULL | ||
54 | }; | ||
55 | |||
56 | static inline int set_rtc_mmss(unsigned long nowtime) | ||
57 | { | ||
58 | return -1; | ||
59 | } | ||
60 | |||
61 | /* | ||
62 | * timer_interrupt() needs to keep up the real-time clock, | ||
63 | * as well as call the "do_timer()" routine every clocktick | ||
64 | */ | ||
65 | static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs) | ||
66 | { | ||
67 | /* last time the cmos clock got updated */ | ||
68 | static long last_rtc_update = 0; | ||
69 | |||
70 | /* | ||
71 | * Here we are in the timer irq handler. We just have irqs locally | ||
72 | * disabled but we don't know if the timer_bh is running on the other | ||
73 | * CPU. We need to avoid to SMP race with it. NOTE: we don' t need | ||
74 | * the irq version of write_lock because as just said we have irq | ||
75 | * locally disabled. -arca | ||
76 | */ | ||
77 | write_seqlock(&xtime_lock); | ||
78 | |||
79 | do_timer(regs); | ||
80 | update_process_times(user_mode(regs)); | ||
81 | profile_tick(CPU_PROFILING, regs); | ||
82 | |||
83 | /* | ||
84 | * If we have an externally synchronized Linux clock, then update | ||
85 | * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be | ||
86 | * called as close as possible to 500 ms before the new second starts. | ||
87 | */ | ||
88 | if ((time_status & STA_UNSYNC) == 0 && | ||
89 | xtime.tv_sec > last_rtc_update + 660 && | ||
90 | (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && | ||
91 | (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2 | ||
92 | ) { | ||
93 | if (set_rtc_mmss(xtime.tv_sec) == 0) | ||
94 | last_rtc_update = xtime.tv_sec; | ||
95 | else | ||
96 | last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ | ||
97 | } | ||
98 | |||
99 | #ifdef CONFIG_HEARTBEAT | ||
100 | static unsigned short n; | ||
101 | n++; | ||
102 | __set_LEDS(n); | ||
103 | #endif /* CONFIG_HEARTBEAT */ | ||
104 | |||
105 | write_sequnlock(&xtime_lock); | ||
106 | return IRQ_HANDLED; | ||
107 | } | ||
108 | |||
109 | void time_divisor_init(void) | ||
110 | { | ||
111 | unsigned short base, pre, prediv; | ||
112 | |||
113 | /* set the scheduling timer going */ | ||
114 | pre = 1; | ||
115 | prediv = 4; | ||
116 | base = __res_bus_clock_speed_HZ / pre / HZ / (1 << prediv); | ||
117 | |||
118 | __set_TPRV(pre); | ||
119 | __set_TxCKSL_DATA(0, prediv); | ||
120 | __set_TCTR(TCTR_SC_CTR0 | TCTR_RL_RW_LH8 | TCTR_MODE_2); | ||
121 | __set_TCSR_DATA(0, base & 0xff); | ||
122 | __set_TCSR_DATA(0, base >> 8); | ||
123 | } | ||
124 | |||
125 | void time_init(void) | ||
126 | { | ||
127 | unsigned int year, mon, day, hour, min, sec; | ||
128 | |||
129 | extern void arch_gettod(int *year, int *mon, int *day, int *hour, int *min, int *sec); | ||
130 | |||
131 | /* FIX by dqg : Set to zero for platforms that don't have tod */ | ||
132 | /* without this time is undefined and can overflow time_t, causing */ | ||
133 | /* very stange errors */ | ||
134 | year = 1980; | ||
135 | mon = day = 1; | ||
136 | hour = min = sec = 0; | ||
137 | arch_gettod (&year, &mon, &day, &hour, &min, &sec); | ||
138 | |||
139 | if ((year += 1900) < 1970) | ||
140 | year += 100; | ||
141 | xtime.tv_sec = mktime(year, mon, day, hour, min, sec); | ||
142 | xtime.tv_nsec = 0; | ||
143 | |||
144 | /* install scheduling interrupt handler */ | ||
145 | setup_irq(IRQ_CPU_TIMER0, &timer_irq); | ||
146 | |||
147 | time_divisor_init(); | ||
148 | } | ||
149 | |||
150 | /* | ||
151 | * This version of gettimeofday has near microsecond resolution. | ||
152 | */ | ||
153 | void do_gettimeofday(struct timeval *tv) | ||
154 | { | ||
155 | unsigned long seq; | ||
156 | unsigned long usec, sec; | ||
157 | unsigned long max_ntp_tick; | ||
158 | |||
159 | do { | ||
160 | unsigned long lost; | ||
161 | |||
162 | seq = read_seqbegin(&xtime_lock); | ||
163 | |||
164 | usec = 0; | ||
165 | lost = jiffies - wall_jiffies; | ||
166 | |||
167 | /* | ||
168 | * If time_adjust is negative then NTP is slowing the clock | ||
169 | * so make sure not to go into next possible interval. | ||
170 | * Better to lose some accuracy than have time go backwards.. | ||
171 | */ | ||
172 | if (unlikely(time_adjust < 0)) { | ||
173 | max_ntp_tick = (USEC_PER_SEC / HZ) - tickadj; | ||
174 | usec = min(usec, max_ntp_tick); | ||
175 | |||
176 | if (lost) | ||
177 | usec += lost * max_ntp_tick; | ||
178 | } | ||
179 | else if (unlikely(lost)) | ||
180 | usec += lost * (USEC_PER_SEC / HZ); | ||
181 | |||
182 | sec = xtime.tv_sec; | ||
183 | usec += (xtime.tv_nsec / 1000); | ||
184 | } while (read_seqretry(&xtime_lock, seq)); | ||
185 | |||
186 | while (usec >= 1000000) { | ||
187 | usec -= 1000000; | ||
188 | sec++; | ||
189 | } | ||
190 | |||
191 | tv->tv_sec = sec; | ||
192 | tv->tv_usec = usec; | ||
193 | } | ||
194 | |||
195 | int do_settimeofday(struct timespec *tv) | ||
196 | { | ||
197 | time_t wtm_sec, sec = tv->tv_sec; | ||
198 | long wtm_nsec, nsec = tv->tv_nsec; | ||
199 | |||
200 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | ||
201 | return -EINVAL; | ||
202 | |||
203 | write_seqlock_irq(&xtime_lock); | ||
204 | /* | ||
205 | * This is revolting. We need to set "xtime" correctly. However, the | ||
206 | * value in this location is the value at the most recent update of | ||
207 | * wall time. Discover what correction gettimeofday() would have | ||
208 | * made, and then undo it! | ||
209 | */ | ||
210 | nsec -= 0 * NSEC_PER_USEC; | ||
211 | nsec -= (jiffies - wall_jiffies) * TICK_NSEC; | ||
212 | |||
213 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); | ||
214 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); | ||
215 | |||
216 | set_normalized_timespec(&xtime, sec, nsec); | ||
217 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); | ||
218 | |||
219 | time_adjust = 0; /* stop active adjtime() */ | ||
220 | time_status |= STA_UNSYNC; | ||
221 | time_maxerror = NTP_PHASE_LIMIT; | ||
222 | time_esterror = NTP_PHASE_LIMIT; | ||
223 | write_sequnlock_irq(&xtime_lock); | ||
224 | clock_was_set(); | ||
225 | return 0; | ||
226 | } | ||
227 | |||
228 | /* | ||
229 | * Scheduler clock - returns current time in nanosec units. | ||
230 | */ | ||
231 | unsigned long long sched_clock(void) | ||
232 | { | ||
233 | return jiffies_64 * (1000000000 / HZ); | ||
234 | } | ||