1 /* mc146818rtc.h - register definitions for the Real-Time-Clock / CMOS RAM 2 * Copyright Torsten Duwe <duwe@informatik.uni-erlangen.de> 1993 3 * derived from Data Sheet, Copyright Motorola 1984 (!). 4 * It was written to be part of the Linux operating system. 5 */ 6 /* permission is hereby granted to copy, modify and redistribute this code 7 * in terms of the GNU Library General Public License, Version 2 or later, 8 * at your option. 9 */ 10 11 #ifndef _MC146818RTC_H 12 #define _MC146818RTC_H 13 #include <asm/io.h> 14 15 #define CMOS_READ(addr) ({ \ 16 outb_p(addr|0x80,0x70); \ 17 inb_p(0x71); \ 18 }) 19 #define CMOS_WRITE(val, addr) ({ \ 20 outb_p(addr|0x80,0x70); \ 21 outb_p(val,0x71); \ 22 }) 23 24 /********************************************************************** 25 * register summary 26 **********************************************************************/ 27 #define RTC_SECONDS 0 28 #define RTC_SECONDS_ALARM 1 29 #define RTC_MINUTES 2 30 #define RTC_MINUTES_ALARM 3 31 #define RTC_HOURS 4 32 #define RTC_HOURS_ALARM 5 33 /* RTC_*_alarm is always true if 2 MSBs are set */ 34 # define RTC_ALARM_DONT_CARE 0xC0 35 36 #define RTC_DAY_OF_WEEK 6 37 #define RTC_DAY_OF_MONTH 7 38 #define RTC_MONTH 8 39 #define RTC_YEAR 9 40 41 /* control registers - Moto names 42 */ 43 #define RTC_REG_A 10 44 #define RTC_REG_B 11 45 #define RTC_REG_C 12 46 #define RTC_REG_D 13 47 48 /********************************************************************** 49 * register details 50 **********************************************************************/ 51 #define RTC_FREQ_SELECT RTC_REG_A 52 53 /* update-in-progress - set to "1" 244 microsecs before RTC goes off the bus, 54 * reset after update (may take 1.984ms @ 32768Hz RefClock) is complete, 55 * totalling to a max high interval of 2.228 ms. 56 */ 57 # define RTC_UIP 0x80 58 # define RTC_DIV_CTL 0x70 59 /* divider control: refclock values 4.194 / 1.049 MHz / 32.768 kHz */ 60 # define RTC_REF_CLCK_4MHZ 0x00 61 # define RTC_REF_CLCK_1MHZ 0x10 62 # define RTC_REF_CLCK_32KHZ 0x20 63 /* 2 values for divider stage reset, others for "testing purposes only" */ 64 # define RTC_DIV_RESET1 0x60 65 # define RTC_DIV_RESET2 0x70 66 /* Periodic intr. / Square wave rate select. 0=none, 1=32.8kHz,... 15=2Hz */ 67 # define RTC_RATE_SELECT 0x0F 68 69 /**********************************************************************/ 70 #define RTC_CONTROL RTC_REG_B 71 # define RTC_SET 0x80 /* disable updates for clock setting */ 72 # define RTC_PIE 0x40 /* periodic interrupt enable */ 73 # define RTC_AIE 0x20 /* alarm interrupt enable */ 74 # define RTC_UIE 0x10 /* update-finished interrupt enable */ 75 # define RTC_SQWE 0x08 /* enable square-wave output */ 76 # define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */ 77 # define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */ 78 # define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */ 79 80 /**********************************************************************/ 81 #define RTC_INTR_FLAGS RTC_REG_C 82 /* caution - cleared by read */ 83 # define RTC_IRQF 0x80 /* any of the following 3 is active */ 84 # define RTC_PF 0x40 85 # define RTC_AF 0x20 86 # define RTC_UF 0x10 87 88 /**********************************************************************/ 89 #define RTC_VALID RTC_REG_D 90 # define RTC_VRT 0x80 /* valid RAM and time */ 91 /**********************************************************************/ 92 93 /* example: !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) 94 * determines if the following two #defines are needed 95 */ 96 #ifndef BCD_TO_BIN 97 #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10) 98 #endif 99 100 #ifndef BIN_TO_BCD 101 #define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10) 102 #endif 103 104 #endif /* _MC146818RTC_H */