Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq
[linux-2.6] / arch / powerpc / platforms / maple / time.c
1 /*
2  *  (c) Copyright 2004 Benjamin Herrenschmidt (benh@kernel.crashing.org),
3  *                     IBM Corp. 
4  *
5  *  This program is free software; you can redistribute it and/or
6  *  modify it under the terms of the GNU General Public License
7  *  as published by the Free Software Foundation; either version
8  *  2 of the License, or (at your option) any later version.
9  *
10  */
11
12 #undef DEBUG
13
14 #include <linux/config.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/mm.h>
21 #include <linux/init.h>
22 #include <linux/time.h>
23 #include <linux/adb.h>
24 #include <linux/pmu.h>
25 #include <linux/interrupt.h>
26 #include <linux/mc146818rtc.h>
27 #include <linux/bcd.h>
28
29 #include <asm/sections.h>
30 #include <asm/prom.h>
31 #include <asm/system.h>
32 #include <asm/io.h>
33 #include <asm/pgtable.h>
34 #include <asm/machdep.h>
35 #include <asm/time.h>
36
37 #include "maple.h"
38
39 #ifdef DEBUG
40 #define DBG(x...) printk(x)
41 #else
42 #define DBG(x...)
43 #endif
44
45 extern void GregorianDay(struct rtc_time * tm);
46
47 static int maple_rtc_addr;
48
49 static int maple_clock_read(int addr)
50 {
51         outb_p(addr, maple_rtc_addr);
52         return inb_p(maple_rtc_addr+1);
53 }
54
55 static void maple_clock_write(unsigned long val, int addr)
56 {
57         outb_p(addr, maple_rtc_addr);
58         outb_p(val, maple_rtc_addr+1);
59 }
60
61 void maple_get_rtc_time(struct rtc_time *tm)
62 {
63         do {
64                 tm->tm_sec = maple_clock_read(RTC_SECONDS);
65                 tm->tm_min = maple_clock_read(RTC_MINUTES);
66                 tm->tm_hour = maple_clock_read(RTC_HOURS);
67                 tm->tm_mday = maple_clock_read(RTC_DAY_OF_MONTH);
68                 tm->tm_mon = maple_clock_read(RTC_MONTH);
69                 tm->tm_year = maple_clock_read(RTC_YEAR);
70         } while (tm->tm_sec != maple_clock_read(RTC_SECONDS));
71
72         if (!(maple_clock_read(RTC_CONTROL) & RTC_DM_BINARY)
73             || RTC_ALWAYS_BCD) {
74                 BCD_TO_BIN(tm->tm_sec);
75                 BCD_TO_BIN(tm->tm_min);
76                 BCD_TO_BIN(tm->tm_hour);
77                 BCD_TO_BIN(tm->tm_mday);
78                 BCD_TO_BIN(tm->tm_mon);
79                 BCD_TO_BIN(tm->tm_year);
80           }
81         if ((tm->tm_year + 1900) < 1970)
82                 tm->tm_year += 100;
83
84         GregorianDay(tm);
85 }
86
87 int maple_set_rtc_time(struct rtc_time *tm)
88 {
89         unsigned char save_control, save_freq_select;
90         int sec, min, hour, mon, mday, year;
91
92         spin_lock(&rtc_lock);
93
94         save_control = maple_clock_read(RTC_CONTROL); /* tell the clock it's being set */
95
96         maple_clock_write((save_control|RTC_SET), RTC_CONTROL);
97
98         save_freq_select = maple_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
99
100         maple_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
101
102         sec = tm->tm_sec;
103         min = tm->tm_min;
104         hour = tm->tm_hour;
105         mon = tm->tm_mon;
106         mday = tm->tm_mday;
107         year = tm->tm_year;
108
109         if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
110                 BIN_TO_BCD(sec);
111                 BIN_TO_BCD(min);
112                 BIN_TO_BCD(hour);
113                 BIN_TO_BCD(mon);
114                 BIN_TO_BCD(mday);
115                 BIN_TO_BCD(year);
116         }
117         maple_clock_write(sec, RTC_SECONDS);
118         maple_clock_write(min, RTC_MINUTES);
119         maple_clock_write(hour, RTC_HOURS);
120         maple_clock_write(mon, RTC_MONTH);
121         maple_clock_write(mday, RTC_DAY_OF_MONTH);
122         maple_clock_write(year, RTC_YEAR);
123
124         /* The following flags have to be released exactly in this order,
125          * otherwise the DS12887 (popular MC146818A clone with integrated
126          * battery and quartz) will not reset the oscillator and will not
127          * update precisely 500 ms later. You won't find this mentioned in
128          * the Dallas Semiconductor data sheets, but who believes data
129          * sheets anyway ...                           -- Markus Kuhn
130          */
131         maple_clock_write(save_control, RTC_CONTROL);
132         maple_clock_write(save_freq_select, RTC_FREQ_SELECT);
133
134         spin_unlock(&rtc_lock);
135
136         return 0;
137 }
138
139 static struct resource rtc_iores = {
140         .name = "rtc",
141         .flags = IORESOURCE_BUSY,
142 };
143
144 unsigned long __init maple_get_boot_time(void)
145 {
146         struct rtc_time tm;
147         struct device_node *rtcs;
148
149         rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
150         if (rtcs) {
151                 struct resource r;
152                 if (of_address_to_resource(rtcs, 0, &r)) {
153                         printk(KERN_EMERG "Maple: Unable to translate RTC"
154                                " address\n");
155                         goto bail;
156                 }
157                 if (!(r.flags & IORESOURCE_IO)) {
158                         printk(KERN_EMERG "Maple: RTC address isn't PIO!\n");
159                         goto bail;
160                 }
161                 maple_rtc_addr = r.start;
162                 printk(KERN_INFO "Maple: Found RTC at IO 0x%x\n",
163                        maple_rtc_addr);
164         }
165  bail:
166         if (maple_rtc_addr == 0) {
167                 maple_rtc_addr = RTC_PORT(0); /* legacy address */
168                 printk(KERN_INFO "Maple: No device node for RTC, assuming "
169                        "legacy address (0x%x)\n", maple_rtc_addr);
170         }
171
172         rtc_iores.start = maple_rtc_addr;
173         rtc_iores.end = maple_rtc_addr + 7;
174         request_resource(&ioport_resource, &rtc_iores);
175
176         maple_get_rtc_time(&tm);
177         return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
178                       tm.tm_hour, tm.tm_min, tm.tm_sec);
179 }
180