Linux 2.6.31.6
[linux/fpc-iii.git] / arch / powerpc / kernel / rtas-rtc.c
blob77578c093ddafc6b57936f9e9715d725ec740829
1 #include <linux/kernel.h>
2 #include <linux/time.h>
3 #include <linux/timer.h>
4 #include <linux/init.h>
5 #include <linux/rtc.h>
6 #include <linux/delay.h>
7 #include <asm/prom.h>
8 #include <asm/rtas.h>
9 #include <asm/time.h>
12 #define MAX_RTC_WAIT 5000 /* 5 sec */
13 #define RTAS_CLOCK_BUSY (-2)
14 unsigned long __init rtas_get_boot_time(void)
16 int ret[8];
17 int error;
18 unsigned int wait_time;
19 u64 max_wait_tb;
21 max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
22 do {
23 error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
25 wait_time = rtas_busy_delay_time(error);
26 if (wait_time) {
27 /* This is boot time so we spin. */
28 udelay(wait_time*1000);
30 } while (wait_time && (get_tb() < max_wait_tb));
32 if (error != 0 && printk_ratelimit()) {
33 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
34 error);
35 return 0;
38 return mktime(ret[0], ret[1], ret[2], ret[3], ret[4], ret[5]);
41 /* NOTE: get_rtc_time will get an error if executed in interrupt context
42 * and if a delay is needed to read the clock. In this case we just
43 * silently return without updating rtc_tm.
45 void rtas_get_rtc_time(struct rtc_time *rtc_tm)
47 int ret[8];
48 int error;
49 unsigned int wait_time;
50 u64 max_wait_tb;
52 max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
53 do {
54 error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
56 wait_time = rtas_busy_delay_time(error);
57 if (wait_time) {
58 if (in_interrupt() && printk_ratelimit()) {
59 memset(rtc_tm, 0, sizeof(struct rtc_time));
60 printk(KERN_WARNING "error: reading clock"
61 " would delay interrupt\n");
62 return; /* delay not allowed */
64 msleep(wait_time);
66 } while (wait_time && (get_tb() < max_wait_tb));
68 if (error != 0 && printk_ratelimit()) {
69 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
70 error);
71 return;
74 rtc_tm->tm_sec = ret[5];
75 rtc_tm->tm_min = ret[4];
76 rtc_tm->tm_hour = ret[3];
77 rtc_tm->tm_mday = ret[2];
78 rtc_tm->tm_mon = ret[1] - 1;
79 rtc_tm->tm_year = ret[0] - 1900;
82 int rtas_set_rtc_time(struct rtc_time *tm)
84 int error, wait_time;
85 u64 max_wait_tb;
87 max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
88 do {
89 error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL,
90 tm->tm_year + 1900, tm->tm_mon + 1,
91 tm->tm_mday, tm->tm_hour, tm->tm_min,
92 tm->tm_sec, 0);
94 wait_time = rtas_busy_delay_time(error);
95 if (wait_time) {
96 if (in_interrupt())
97 return 1; /* probably decrementer */
98 msleep(wait_time);
100 } while (wait_time && (get_tb() < max_wait_tb));
102 if (error != 0 && printk_ratelimit())
103 printk(KERN_WARNING "error: setting the clock failed (%d)\n",
104 error);
106 return 0;