[POWERPC] Only export __mtdcr/__mfdcr if CONFIG_PPC_DCR is set
[linux-2.6] / arch / powerpc / kernel / rtas-rtc.c
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>
10
11
12 #define MAX_RTC_WAIT 5000       /* 5 sec */
13 #define RTAS_CLOCK_BUSY (-2)
14 unsigned long __init rtas_get_boot_time(void)
15 {
16         int ret[8];
17         int error;
18         unsigned int wait_time;
19         u64 max_wait_tb;
20
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);
24
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);
29                 }
30         } while (wait_time && (get_tb() < max_wait_tb));
31
32         if (error != 0 && printk_ratelimit()) {
33                 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
34                         error);
35                 return 0;
36         }
37
38         return mktime(ret[0], ret[1], ret[2], ret[3], ret[4], ret[5]);
39 }
40
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.
44  */
45 void rtas_get_rtc_time(struct rtc_time *rtc_tm)
46 {
47         int ret[8];
48         int error;
49         unsigned int wait_time;
50         u64 max_wait_tb;
51
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);
55
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 */
63                         }
64                         msleep(wait_time);
65                 }
66         } while (wait_time && (get_tb() < max_wait_tb));
67
68         if (error != 0 && printk_ratelimit()) {
69                 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
70                        error);
71                 return;
72         }
73
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;
80 }
81
82 int rtas_set_rtc_time(struct rtc_time *tm)
83 {
84         int error, wait_time;
85         u64 max_wait_tb;
86
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);
93
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);
99                 }
100         } while (wait_time && (get_tb() < max_wait_tb));
101
102         if (error != 0 && printk_ratelimit())
103                 printk(KERN_WARNING "error: setting the clock failed (%d)\n",
104                        error);
105
106         return 0;
107 }