Line data Source code
1 : /*
2 : * include/asm-generic/rtc.h
3 : *
4 : * Author: Tom Rini <trini@mvista.com>
5 : *
6 : * Based on:
7 : * drivers/char/rtc.c
8 : *
9 : * Please read the COPYING file for all license details.
10 : */
11 :
12 : #ifndef __ASM_RTC_H__
13 : #define __ASM_RTC_H__
14 :
15 : #include <linux/mc146818rtc.h>
16 : #include <linux/rtc.h>
17 : #include <linux/bcd.h>
18 : #include <linux/delay.h>
19 :
20 : #define RTC_PIE 0x40 /* periodic interrupt enable */
21 : #define RTC_AIE 0x20 /* alarm interrupt enable */
22 : #define RTC_UIE 0x10 /* update-finished interrupt enable */
23 :
24 : /* some dummy definitions */
25 : #define RTC_BATT_BAD 0x100 /* battery bad */
26 : #define RTC_SQWE 0x08 /* enable square-wave output */
27 : #define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */
28 : #define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */
29 : #define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */
30 :
31 : /*
32 : * Returns true if a clock update is in progress
33 : */
34 : static inline unsigned char rtc_is_updating(void)
35 : {
36 1 : unsigned char uip;
37 1 : unsigned long flags;
38 1 :
39 4 : spin_lock_irqsave(&rtc_lock, flags);
40 2 : uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
41 2 : spin_unlock_irqrestore(&rtc_lock, flags);
42 1 : return uip;
43 : }
44 :
45 : static inline unsigned int __get_rtc_time(struct rtc_time *time)
46 : {
47 1 : unsigned char ctrl;
48 1 : unsigned long flags;
49 1 :
50 1 : #ifdef CONFIG_MACH_DECSTATION
51 1 : unsigned int real_year;
52 1 : #endif
53 1 :
54 1 : /*
55 1 : * read RTC once any update in progress is done. The update
56 1 : * can take just over 2ms. We wait 20ms. There is no need to
57 1 : * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
58 1 : * If you need to know *exactly* when a second has started, enable
59 1 : * periodic update complete interrupts, (via ioctl) and then
60 1 : * immediately read /dev/rtc which will block until you get the IRQ.
61 1 : * Once the read clears, read the RTC time (again via ioctl). Easy.
62 1 : */
63 5 : if (rtc_is_updating())
64 8 : mdelay(20);
65 1 :
66 2 : /*
67 : * Only the values that we read from the RTC are set. We leave
68 : * tm_wday, tm_yday and tm_isdst untouched. Even though the
69 : * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
70 : * by the RTC when initially set to a non-zero value.
71 : */
72 5 : spin_lock_irqsave(&rtc_lock, flags);
73 2 : time->tm_sec = CMOS_READ(RTC_SECONDS);
74 2 : time->tm_min = CMOS_READ(RTC_MINUTES);
75 2 : time->tm_hour = CMOS_READ(RTC_HOURS);
76 2 : time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
77 2 : time->tm_mon = CMOS_READ(RTC_MONTH);
78 2 : time->tm_year = CMOS_READ(RTC_YEAR);
79 : #ifdef CONFIG_MACH_DECSTATION
80 : real_year = CMOS_READ(RTC_DEC_YEAR);
81 : #endif
82 1 : ctrl = CMOS_READ(RTC_CONTROL);
83 2 : spin_unlock_irqrestore(&rtc_lock, flags);
84 :
85 : if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
86 : {
87 3 : time->tm_sec = bcd2bin(time->tm_sec);
88 3 : time->tm_min = bcd2bin(time->tm_min);
89 3 : time->tm_hour = bcd2bin(time->tm_hour);
90 3 : time->tm_mday = bcd2bin(time->tm_mday);
91 3 : time->tm_mon = bcd2bin(time->tm_mon);
92 3 : time->tm_year = bcd2bin(time->tm_year);
93 : }
94 :
95 : #ifdef CONFIG_MACH_DECSTATION
96 : time->tm_year += real_year - 72;
97 : #endif
98 :
99 : /*
100 : * Account for differences between how the RTC uses the values
101 : * and how they are defined in a struct rtc_time;
102 : */
103 2 : if (time->tm_year <= 69)
104 1 : time->tm_year += 100;
105 :
106 1 : time->tm_mon--;
107 :
108 1 : return RTC_24H;
109 : }
110 :
111 : #ifndef get_rtc_time
112 : #define get_rtc_time __get_rtc_time
113 : #endif
114 :
115 : /* Set the current date and time in the real time clock. */
116 : static inline int __set_rtc_time(struct rtc_time *time)
117 : {
118 1 : unsigned long flags;
119 1 : unsigned char mon, day, hrs, min, sec;
120 1 : unsigned char save_control, save_freq_select;
121 1 : unsigned int yrs;
122 1 : #ifdef CONFIG_MACH_DECSTATION
123 1 : unsigned int real_yrs, leap_yr;
124 1 : #endif
125 1 :
126 3 : yrs = time->tm_year;
127 3 : mon = time->tm_mon + 1; /* tm_mon starts at zero */
128 3 : day = time->tm_mday;
129 2 : hrs = time->tm_hour;
130 2 : min = time->tm_min;
131 2 : sec = time->tm_sec;
132 :
133 2 : if (yrs > 255) /* They are unsigned */
134 1 : return -EINVAL;
135 :
136 3 : spin_lock_irqsave(&rtc_lock, flags);
137 : #ifdef CONFIG_MACH_DECSTATION
138 : real_yrs = yrs;
139 : leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) ||
140 : !((yrs + 1900) % 400));
141 : yrs = 72;
142 :
143 : /*
144 : * We want to keep the year set to 73 until March
145 : * for non-leap years, so that Feb, 29th is handled
146 : * correctly.
147 : */
148 : if (!leap_yr && mon < 3) {
149 : real_yrs--;
150 : yrs = 73;
151 : }
152 : #endif
153 : /* These limits and adjustments are independent of
154 : * whether the chip is in binary mode or not.
155 : */
156 2 : if (yrs > 169) {
157 2 : spin_unlock_irqrestore(&rtc_lock, flags);
158 1 : return -EINVAL;
159 : }
160 :
161 2 : if (yrs >= 100)
162 1 : yrs -= 100;
163 :
164 1 : if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
165 : || RTC_ALWAYS_BCD) {
166 1 : sec = bin2bcd(sec);
167 1 : min = bin2bcd(min);
168 1 : hrs = bin2bcd(hrs);
169 1 : day = bin2bcd(day);
170 1 : mon = bin2bcd(mon);
171 2 : yrs = bin2bcd(yrs);
172 : }
173 :
174 1 : save_control = CMOS_READ(RTC_CONTROL);
175 1 : CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
176 1 : save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
177 1 : CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
178 :
179 : #ifdef CONFIG_MACH_DECSTATION
180 : CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
181 : #endif
182 1 : CMOS_WRITE(yrs, RTC_YEAR);
183 1 : CMOS_WRITE(mon, RTC_MONTH);
184 1 : CMOS_WRITE(day, RTC_DAY_OF_MONTH);
185 1 : CMOS_WRITE(hrs, RTC_HOURS);
186 1 : CMOS_WRITE(min, RTC_MINUTES);
187 1 : CMOS_WRITE(sec, RTC_SECONDS);
188 :
189 1 : CMOS_WRITE(save_control, RTC_CONTROL);
190 1 : CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
191 :
192 2 : spin_unlock_irqrestore(&rtc_lock, flags);
193 :
194 1 : return 0;
195 : }
196 :
197 : #ifndef set_rtc_time
198 : #define set_rtc_time __set_rtc_time
199 : #endif
200 :
201 : static inline unsigned int get_rtc_ss(void)
202 : {
203 : struct rtc_time h;
204 :
205 : get_rtc_time(&h);
206 : return h.tm_sec;
207 : }
208 :
209 : static inline int get_rtc_pll(struct rtc_pll_info *pll)
210 : {
211 : return -EINVAL;
212 : }
213 : static inline int set_rtc_pll(struct rtc_pll_info *pll)
214 : {
215 : return -EINVAL;
216 : }
217 1 :
218 : #endif /* __ASM_RTC_H__ */
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