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-rw-r--r--arch/xtensa/kernel/time.c131
1 files changed, 26 insertions, 105 deletions
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c
index 8df1e842f6d4..8848120d291b 100644
--- a/arch/xtensa/kernel/time.c
+++ b/arch/xtensa/kernel/time.c
@@ -14,7 +14,7 @@
14 14
15#include <linux/errno.h> 15#include <linux/errno.h>
16#include <linux/time.h> 16#include <linux/time.h>
17#include <linux/timex.h> 17#include <linux/clocksource.h>
18#include <linux/interrupt.h> 18#include <linux/interrupt.h>
19#include <linux/module.h> 19#include <linux/module.h>
20#include <linux/init.h> 20#include <linux/init.h>
@@ -25,27 +25,31 @@
25#include <asm/timex.h> 25#include <asm/timex.h>
26#include <asm/platform.h> 26#include <asm/platform.h>
27 27
28
29DEFINE_SPINLOCK(rtc_lock);
30EXPORT_SYMBOL(rtc_lock);
31
32
33#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT 28#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
34unsigned long ccount_per_jiffy; /* per 1/HZ */ 29unsigned long ccount_per_jiffy; /* per 1/HZ */
35unsigned long nsec_per_ccount; /* nsec per ccount increment */ 30unsigned long nsec_per_ccount; /* nsec per ccount increment */
36#endif 31#endif
37 32
38static long last_rtc_update = 0; 33static cycle_t ccount_read(void)
39
40/*
41 * Scheduler clock - returns current tim in nanosec units.
42 */
43
44unsigned long long sched_clock(void)
45{ 34{
46 return (unsigned long long)jiffies * (1000000000 / HZ); 35 return (cycle_t)get_ccount();
47} 36}
48 37
38static struct clocksource ccount_clocksource = {
39 .name = "ccount",
40 .rating = 200,
41 .read = ccount_read,
42 .mask = CLOCKSOURCE_MASK(32),
43 /*
44 * With a shift of 22 the lower limit of the cpu clock is
45 * 1MHz, where NSEC_PER_CCOUNT is 1000 or a bit less than
46 * 2^10: Since we have 32 bits and the multiplicator can
47 * already take up as much as 10 bits, this leaves us with
48 * remaining upper 22 bits.
49 */
50 .shift = 22,
51};
52
49static irqreturn_t timer_interrupt(int irq, void *dev_id); 53static irqreturn_t timer_interrupt(int irq, void *dev_id);
50static struct irqaction timer_irqaction = { 54static struct irqaction timer_irqaction = {
51 .handler = timer_interrupt, 55 .handler = timer_interrupt,
@@ -55,11 +59,11 @@ static struct irqaction timer_irqaction = {
55 59
56void __init time_init(void) 60void __init time_init(void)
57{ 61{
58 time_t sec_o, sec_n = 0; 62 xtime.tv_nsec = 0;
63 xtime.tv_sec = read_persistent_clock();
59 64
60 /* The platform must provide a function to calibrate the processor 65 set_normalized_timespec(&wall_to_monotonic,
61 * speed for the CALIBRATE. 66 -xtime.tv_sec, -xtime.tv_nsec);
62 */
63 67
64#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT 68#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
65 printk("Calibrating CPU frequency "); 69 printk("Calibrating CPU frequency ");
@@ -67,19 +71,10 @@ void __init time_init(void)
67 printk("%d.%02d MHz\n", (int)ccount_per_jiffy/(1000000/HZ), 71 printk("%d.%02d MHz\n", (int)ccount_per_jiffy/(1000000/HZ),
68 (int)(ccount_per_jiffy/(10000/HZ))%100); 72 (int)(ccount_per_jiffy/(10000/HZ))%100);
69#endif 73#endif
70 74 ccount_clocksource.mult =
71 /* Set time from RTC (if provided) */ 75 clocksource_hz2mult(CCOUNT_PER_JIFFY * HZ,
72 76 ccount_clocksource.shift);
73 if (platform_get_rtc_time(&sec_o) == 0) 77 clocksource_register(&ccount_clocksource);
74 while (platform_get_rtc_time(&sec_n))
75 if (sec_o != sec_n)
76 break;
77
78 xtime.tv_nsec = 0;
79 last_rtc_update = xtime.tv_sec = sec_n;
80
81 set_normalized_timespec(&wall_to_monotonic,
82 -xtime.tv_sec, -xtime.tv_nsec);
83 78
84 /* Initialize the linux timer interrupt. */ 79 /* Initialize the linux timer interrupt. */
85 80
@@ -87,69 +82,6 @@ void __init time_init(void)
87 set_linux_timer(get_ccount() + CCOUNT_PER_JIFFY); 82 set_linux_timer(get_ccount() + CCOUNT_PER_JIFFY);
88} 83}
89 84
90
91int do_settimeofday(struct timespec *tv)
92{
93 time_t wtm_sec, sec = tv->tv_sec;
94 long wtm_nsec, nsec = tv->tv_nsec;
95 unsigned long delta;
96
97 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
98 return -EINVAL;
99
100 write_seqlock_irq(&xtime_lock);
101
102 /* This is revolting. We need to set "xtime" correctly. However, the
103 * value in this location is the value at the most recent update of
104 * wall time. Discover what correction gettimeofday() would have
105 * made, and then undo it!
106 */
107
108 delta = CCOUNT_PER_JIFFY;
109 delta += get_ccount() - get_linux_timer();
110 nsec -= delta * NSEC_PER_CCOUNT;
111
112 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
113 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
114
115 set_normalized_timespec(&xtime, sec, nsec);
116 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
117
118 ntp_clear();
119 write_sequnlock_irq(&xtime_lock);
120 return 0;
121}
122
123EXPORT_SYMBOL(do_settimeofday);
124
125
126void do_gettimeofday(struct timeval *tv)
127{
128 unsigned long flags;
129 unsigned long volatile sec, usec, delta, seq;
130
131 do {
132 seq = read_seqbegin_irqsave(&xtime_lock, flags);
133
134 sec = xtime.tv_sec;
135 usec = (xtime.tv_nsec / NSEC_PER_USEC);
136
137 delta = get_linux_timer() - get_ccount();
138
139 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
140
141 usec += (((unsigned long) CCOUNT_PER_JIFFY - delta)
142 * (unsigned long) NSEC_PER_CCOUNT) / NSEC_PER_USEC;
143
144 for (; usec >= 1000000; sec++, usec -= 1000000)
145 ;
146
147 tv->tv_sec = sec;
148 tv->tv_usec = usec;
149}
150
151EXPORT_SYMBOL(do_gettimeofday);
152
153/* 85/*
154 * The timer interrupt is called HZ times per second. 86 * The timer interrupt is called HZ times per second.
155 */ 87 */
@@ -178,16 +110,6 @@ again:
178 next += CCOUNT_PER_JIFFY; 110 next += CCOUNT_PER_JIFFY;
179 set_linux_timer(next); 111 set_linux_timer(next);
180 112
181 if (ntp_synced() &&
182 xtime.tv_sec - last_rtc_update >= 659 &&
183 abs((xtime.tv_nsec/1000)-(1000000-1000000/HZ))<5000000/HZ) {
184
185 if (platform_set_rtc_time(xtime.tv_sec+1) == 0)
186 last_rtc_update = xtime.tv_sec+1;
187 else
188 /* Do it again in 60 s */
189 last_rtc_update += 60;
190 }
191 write_sequnlock(&xtime_lock); 113 write_sequnlock(&xtime_lock);
192 } 114 }
193 115
@@ -213,4 +135,3 @@ void __cpuinit calibrate_delay(void)
213 (loops_per_jiffy/(10000/HZ)) % 100); 135 (loops_per_jiffy/(10000/HZ)) % 100);
214} 136}
215#endif 137#endif
216