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 */ 34static inline unsigned char rtc_is_updating(void) 35{ 36 unsigned char uip; 37 unsigned long flags; 38 39 spin_lock_irqsave(&rtc_lock, flags); 40 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); 41 spin_unlock_irqrestore(&rtc_lock, flags); 42 return uip; 43} 44 45static inline unsigned int __get_rtc_time(struct rtc_time *time) 46{ 47 unsigned char ctrl; 48 unsigned long flags; 49 50#ifdef CONFIG_MACH_DECSTATION 51 unsigned int real_year; 52#endif 53 54 /* 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. 62 */ 63 if (rtc_is_updating()) 64 mdelay(20); 65 66 /* 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 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); 81#endif 82 ctrl = CMOS_READ(RTC_CONTROL); 83 spin_unlock_irqrestore(&rtc_lock, flags); 84 85 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) 86 { 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); 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 if (time->tm_year <= 69) 104 time->tm_year += 100; 105 106 time->tm_mon--; 107 108 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. */ 116static inline int __set_rtc_time(struct rtc_time *time) 117{ 118 unsigned long flags; 119 unsigned char mon, day, hrs, min, sec; 120 unsigned char save_control, save_freq_select; 121 unsigned int yrs; 122#ifdef CONFIG_MACH_DECSTATION 123 unsigned int real_yrs, leap_yr; 124#endif 125 126 yrs = time->tm_year; 127 mon = time->tm_mon + 1; /* tm_mon starts at zero */ 128 day = time->tm_mday; 129 hrs = time->tm_hour; 130 min = time->tm_min; 131 sec = time->tm_sec; 132 133 if (yrs > 255) /* They are unsigned */ 134 return -EINVAL; 135 136 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 if (yrs > 169) { 157 spin_unlock_irqrestore(&rtc_lock, flags); 158 return -EINVAL; 159 } 160 161 if (yrs >= 100) 162 yrs -= 100; 163 164 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) 165 || RTC_ALWAYS_BCD) { 166 sec = bin2bcd(sec); 167 min = bin2bcd(min); 168 hrs = bin2bcd(hrs); 169 day = bin2bcd(day); 170 mon = bin2bcd(mon); 171 yrs = bin2bcd(yrs); 172 } 173 174 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); 178 179#ifdef CONFIG_MACH_DECSTATION 180 CMOS_WRITE(real_yrs, RTC_DEC_YEAR); 181#endif 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); 188 189 CMOS_WRITE(save_control, RTC_CONTROL); 190 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); 191 192 spin_unlock_irqrestore(&rtc_lock, flags); 193 194 return 0; 195} 196 197#ifndef set_rtc_time 198#define set_rtc_time __set_rtc_time 199#endif 200 201static 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 209static inline int get_rtc_pll(struct rtc_pll_info *pll) 210{ 211 return -EINVAL; 212} 213static inline int set_rtc_pll(struct rtc_pll_info *pll) 214{ 215 return -EINVAL; 216} 217 218#endif /* __ASM_RTC_H__ */ 219