2 * include/asm-generic/rtc.h
4 * Author: Tom Rini <trini@mvista.com>
9 * Please read the COPYING file for all license details.
15 #include <linux/mc146818rtc.h>
16 #include <linux/rtc.h>
17 #include <linux/bcd.h>
18 #include <linux/delay.h>
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 */
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 */
32 * Returns true if a clock update is in progress
34 static inline unsigned char rtc_is_updating(void)
39 spin_lock_irqsave(&rtc_lock, flags);
40 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
41 spin_unlock_irqrestore(&rtc_lock, flags);
45 static inline unsigned int __get_rtc_time(struct rtc_time *time)
50 #ifdef CONFIG_MACH_DECSTATION
51 unsigned int real_year;
55 * read RTC once any update in progress is done. The update
56 * can take just over 2ms. We wait 20ms. There is no need to
57 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
58 * If you need to know *exactly* when a second has started, enable
59 * periodic update complete interrupts, (via ioctl) and then
60 * immediately read /dev/rtc which will block until you get the IRQ.
61 * Once the read clears, read the RTC time (again via ioctl). Easy.
63 if (rtc_is_updating())
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.
72 spin_lock_irqsave(&rtc_lock, flags);
73 time->tm_sec = CMOS_READ(RTC_SECONDS);
74 time->tm_min = CMOS_READ(RTC_MINUTES);
75 time->tm_hour = CMOS_READ(RTC_HOURS);
76 time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
77 time->tm_mon = CMOS_READ(RTC_MONTH);
78 time->tm_year = CMOS_READ(RTC_YEAR);
79 #ifdef CONFIG_MACH_DECSTATION
80 real_year = CMOS_READ(RTC_DEC_YEAR);
82 ctrl = CMOS_READ(RTC_CONTROL);
83 spin_unlock_irqrestore(&rtc_lock, flags);
85 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
87 time->tm_sec = bcd2bin(time->tm_sec);
88 time->tm_min = bcd2bin(time->tm_min);
89 time->tm_hour = bcd2bin(time->tm_hour);
90 time->tm_mday = bcd2bin(time->tm_mday);
91 time->tm_mon = bcd2bin(time->tm_mon);
92 time->tm_year = bcd2bin(time->tm_year);
95 #ifdef CONFIG_MACH_DECSTATION
96 time->tm_year += real_year - 72;
100 * Account for differences between how the RTC uses the values
101 * and how they are defined in a struct rtc_time;
103 if (time->tm_year <= 69)
104 time->tm_year += 100;
112 #define get_rtc_time __get_rtc_time
115 /* Set the current date and time in the real time clock. */
116 static inline int __set_rtc_time(struct rtc_time *time)
119 unsigned char mon, day, hrs, min, sec;
120 unsigned char save_control, save_freq_select;
122 #ifdef CONFIG_MACH_DECSTATION
123 unsigned int real_yrs, leap_yr;
127 mon = time->tm_mon + 1; /* tm_mon starts at zero */
133 if (yrs > 255) /* They are unsigned */
136 spin_lock_irqsave(&rtc_lock, flags);
137 #ifdef CONFIG_MACH_DECSTATION
139 leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) ||
140 !((yrs + 1900) % 400));
144 * We want to keep the year set to 73 until March
145 * for non-leap years, so that Feb, 29th is handled
148 if (!leap_yr && mon < 3) {
153 /* These limits and adjustments are independent of
154 * whether the chip is in binary mode or not.
157 spin_unlock_irqrestore(&rtc_lock, flags);
164 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
174 save_control = CMOS_READ(RTC_CONTROL);
175 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
176 save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
177 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
179 #ifdef CONFIG_MACH_DECSTATION
180 CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
182 CMOS_WRITE(yrs, RTC_YEAR);
183 CMOS_WRITE(mon, RTC_MONTH);
184 CMOS_WRITE(day, RTC_DAY_OF_MONTH);
185 CMOS_WRITE(hrs, RTC_HOURS);
186 CMOS_WRITE(min, RTC_MINUTES);
187 CMOS_WRITE(sec, RTC_SECONDS);
189 CMOS_WRITE(save_control, RTC_CONTROL);
190 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
192 spin_unlock_irqrestore(&rtc_lock, flags);
198 #define set_rtc_time __set_rtc_time
201 static inline unsigned int get_rtc_ss(void)
209 static inline int get_rtc_pll(struct rtc_pll_info *pll)
213 static inline int set_rtc_pll(struct rtc_pll_info *pll)
218 #endif /* __ASM_RTC_H__ */