root/include/linux/mc146818rtc.h

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   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 #ifndef RTC_PORT
  16 #define RTC_PORT(x)     (0x70 + (x))
  17 #define RTC_ADDR(x)     (0x80 | (x))
  18 #define RTC_ALWAYS_BCD  1
  19 #endif
  20 
  21 #define CMOS_READ(addr) ({ \
  22 outb_p(RTC_ADDR(addr),RTC_PORT(0)); \
  23 inb_p(RTC_PORT(1)); \
  24 })
  25 #define CMOS_WRITE(val, addr) ({ \
  26 outb_p(RTC_ADDR(addr),RTC_PORT(0)); \
  27 outb_p(val,RTC_PORT(1)); \
  28 })
  29 
  30 /**********************************************************************
  31  * register summary
  32  **********************************************************************/
  33 #define RTC_SECONDS             0
  34 #define RTC_SECONDS_ALARM       1
  35 #define RTC_MINUTES             2
  36 #define RTC_MINUTES_ALARM       3
  37 #define RTC_HOURS               4
  38 #define RTC_HOURS_ALARM         5
  39 /* RTC_*_alarm is always true if 2 MSBs are set */
  40 # define RTC_ALARM_DONT_CARE    0xC0
  41 
  42 #define RTC_DAY_OF_WEEK         6
  43 #define RTC_DAY_OF_MONTH        7
  44 #define RTC_MONTH               8
  45 #define RTC_YEAR                9
  46 
  47 /* control registers - Moto names
  48  */
  49 #define RTC_REG_A               10
  50 #define RTC_REG_B               11
  51 #define RTC_REG_C               12
  52 #define RTC_REG_D               13
  53 
  54 /**********************************************************************
  55  * register details
  56  **********************************************************************/
  57 #define RTC_FREQ_SELECT RTC_REG_A
  58 
  59 /* update-in-progress  - set to "1" 244 microsecs before RTC goes off the bus,
  60  * reset after update (may take 1.984ms @ 32768Hz RefClock) is complete,
  61  * totalling to a max high interval of 2.228 ms.
  62  */
  63 # define RTC_UIP                0x80
  64 # define RTC_DIV_CTL            0x70
  65    /* divider control: refclock values 4.194 / 1.049 MHz / 32.768 kHz */
  66 #  define RTC_REF_CLCK_4MHZ     0x00
  67 #  define RTC_REF_CLCK_1MHZ     0x10
  68 #  define RTC_REF_CLCK_32KHZ    0x20
  69    /* 2 values for divider stage reset, others for "testing purposes only" */
  70 #  define RTC_DIV_RESET1        0x60
  71 #  define RTC_DIV_RESET2        0x70
  72   /* Periodic intr. / Square wave rate select. 0=none, 1=32.8kHz,... 15=2Hz */
  73 # define RTC_RATE_SELECT        0x0F
  74 
  75 /**********************************************************************/
  76 #define RTC_CONTROL     RTC_REG_B
  77 # define RTC_SET 0x80           /* disable updates for clock setting */
  78 # define RTC_PIE 0x40           /* periodic interrupt enable */
  79 # define RTC_AIE 0x20           /* alarm interrupt enable */
  80 # define RTC_UIE 0x10           /* update-finished interrupt enable */
  81 # define RTC_SQWE 0x08          /* enable square-wave output */
  82 # define RTC_DM_BINARY 0x04     /* all time/date values are BCD if clear */
  83 # define RTC_24H 0x02           /* 24 hour mode - else hours bit 7 means pm */
  84 # define RTC_DST_EN 0x01        /* auto switch DST - works f. USA only */
  85 
  86 /**********************************************************************/
  87 #define RTC_INTR_FLAGS  RTC_REG_C
  88 /* caution - cleared by read */
  89 # define RTC_IRQF 0x80          /* any of the following 3 is active */
  90 # define RTC_PF 0x40
  91 # define RTC_AF 0x20
  92 # define RTC_UF 0x10
  93 
  94 /**********************************************************************/
  95 #define RTC_VALID       RTC_REG_D
  96 # define RTC_VRT 0x80           /* valid RAM and time */
  97 /**********************************************************************/
  98 
  99 /* example: !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) 
 100  * determines if the following two #defines are needed
 101  */
 102 #ifndef BCD_TO_BIN
 103 #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
 104 #endif
 105 
 106 #ifndef BIN_TO_BCD
 107 #define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10)
 108 #endif
 109 
 110 #endif /* _MC146818RTC_H */

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