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