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/* $NetBSD: mc146818reg.h,v 1.2 1997/03/12 06:53:42 cgd Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* Definitions for the Motorola MC146818A Real Time Clock.
* They also apply for the (compatible) Dallas Semicontuctor DS1287A RTC.
*
* Though there are undoubtedly other (better) sources, this material was
* culled from the DEC "KN121 System Module Programmer's Reference
* Information."
*
* The MC146818A has 16 registers. The first 10 contain time-of-year
* and alarm data. The rest contain various control and status bits.
*
* To read or write the registers, one writes the register number to
* the RTC's control port, then either reads from or writes the new
* data to the RTC's data port. Since the locations of these ports
* and the method used to access them can be machine-dependent, the
* low-level details of reading and writing the RTC's registers are
* handled by machine-specific functions.
*
* The time-of-year and alarm data can be expressed in either binary
* or BCD, and they are selected by a bit in register B.
*
* The "hour" time-of-year and alarm fields can either be expressed in
* AM/PM format, or in 24-hour format. If AM/PM format is chosen, the
* hour fields can have the values: 1-12 and 81-92 (the latter being
* PM). If the 24-hour format is chosen, they can have the values
* 0-24. The hour format is selectable by a bit in register B.
* (XXX IS AM/PM MODE DESCRIPTION CORRECT?)
*
* It is assumed the if systems are going to use BCD (rather than
* binary) mode, or AM/PM hour format, they'll do the appropriate
* conversions in machine-dependent code. Also, if the clock is
* switched between BCD and binary mode, or between AM/PM mode and
* 24-hour mode, the time-of-day and alarm registers are NOT
* automatically reset; they must be reprogrammed with correct values.
*/
/*
* The registers, and the bits within each register.
*/
#define MC_SEC 0x0 /* Time of year: seconds (0-59) */
#define MC_ASEC 0x1 /* Alarm: seconds */
#define MC_MIN 0x2 /* Time of year: minutes (0-59) */
#define MC_AMIN 0x3 /* Alarm: minutes */
#define MC_HOUR 0x4 /* Time of year: hour (see above) */
#define MC_AHOUR 0x5 /* Alarm: hour */
#define MC_DOW 0x6 /* Time of year: day of week (1-7) */
#define MC_DOM 0x7 /* Time of year: day of month (1-31) */
#define MC_MONTH 0x8 /* Time of year: month (1-12) */
#define MC_YEAR 0x9 /* Time of year: year in century (0-99) */
#define MC_REGA 0xa /* Control register A */
#define MC_REGA_RSMASK 0x0f /* Interrupt rate select mask (see below) */
#define MC_REGA_DVMASK 0x70 /* Divisor select mask (see below) */
#define MC_REGA_UIP 0x80 /* Update in progress; read only. */
#define MC_REGB 0xb /* Control register B */
#define MC_REGB_DSE 0x01 /* Daylight Savings Enable */
#define MC_REGB_24HR 0x02 /* 24-hour mode (AM/PM mode when clear) */
#define MC_REGB_BINARY 0x04 /* Binary mode (BCD mode when clear) */
#define MC_REGB_SQWE 0x08 /* Square Wave Enable */
#define MC_REGB_UIE 0x10 /* Update End interrupt enable */
#define MC_REGB_AIE 0x20 /* Alarm interrupt enable */
#define MC_REGB_PIE 0x40 /* Periodic interrupt enable */
#define MC_REGB_SET 0x80 /* Allow time to be set; stops updates */
#define MC_REGC 0xc /* Control register C */
/* MC_REGC_UNUSED 0x0f UNUSED */
#define MC_REGC_UF 0x10 /* Update End interrupt flag */
#define MC_REGC_AF 0x20 /* Alarm interrupt flag */
#define MC_REGC_PF 0x40 /* Periodic interrupt flag */
#define MC_REGC_IRQF 0x80 /* Interrupt request pending flag */
#define MC_REGD 0xd /* Control register D */
/* MC_REGD_UNUSED 0x7f UNUSED */
#define MC_REGD_VRT 0x80 /* Valid RAM and Time bit */
#define MC_NREGS 0xe /* 14 registers; CMOS follows */
#define MC_NTODREGS 0xa /* 10 of those regs are for TOD and alarm */
#define MC_NVRAM_START 0xe /* start of NVRAM: offset 14 */
#define MC_NVRAM_SIZE 50 /* 50 bytes of NVRAM */
/*
* Periodic Interrupt Rate Select constants (Control register A)
*/
#define MC_RATE_NONE 0x0 /* No periodic interrupt */
#define MC_RATE_1 0x1 /* 256 Hz if MC_BASE_32_KHz, else 32768 Hz */
#define MC_RATE_2 0x2 /* 128 Hz if MC_BASE_32_KHz, else 16384 Hz */
#define MC_RATE_8192_Hz 0x3 /* 122.070 us period */
#define MC_RATE_4096_Hz 0x4 /* 244.141 us period */
#define MC_RATE_2048_Hz 0x5 /* 488.281 us period */
#define MC_RATE_1024_Hz 0x6 /* 976.562 us period */
#define MC_RATE_512_Hz 0x7 /* 1.953125 ms period */
#define MC_RATE_256_Hz 0x8 /* 3.90625 ms period */
#define MC_RATE_128_Hz 0x9 /* 7.8125 ms period */
#define MC_RATE_64_Hz 0xa /* 15.625 ms period */
#define MC_RATE_32_Hz 0xb /* 31.25 ms period */
#define MC_RATE_16_Hz 0xc /* 62.5 ms period */
#define MC_RATE_8_Hz 0xd /* 125 ms period */
#define MC_RATE_4_Hz 0xe /* 250 ms period */
#define MC_RATE_2_Hz 0xf /* 500 ms period */
/*
* Time base (divisor select) constants (Control register A)
*/
#define MC_BASE_4_MHz 0x00 /* 4MHz crystal */
#define MC_BASE_1_MHz 0x10 /* 1MHz crystal */
#define MC_BASE_32_KHz 0x20 /* 32KHz crystal */
#define MC_BASE_NONE 0x60 /* actually, both of these reset */
#define MC_BASE_RESET 0x70
/*
* A collection of TOD/Alarm registers.
*/
typedef u_int mc_todregs[MC_NTODREGS];
/*
* Get all of the TOD/Alarm registers
* Must be called at splhigh(), and with the RTC properly set up.
*/
#define MC146818_GETTOD(dev, regs) \
do { \
int i; \
\
/* update in progress; spin loop */ \
while (MCCLOCK_READ(dev, MC_REGA) & MC_REGA_UIP) \
; \
\
/* read all of the tod/alarm regs */ \
for (i = 0; i < MC_NTODREGS; i++) \
(*regs)[i] = MCCLOCK_READ(dev, i); \
} while (0);
/*
* Set all of the TOD/Alarm registers
* Must be called at splhigh(), and with the RTC properly set up.
*/
#define MC146818_PUTTOD(dev, regs) \
do { \
int i; \
\
/* stop updates while setting */ \
MCCLOCK_WRITE(dev, MC_REGB, \
MCCLOCK_READ(dev, MC_REGB) | MC_REGB_SET); \
\
/* write all of the tod/alarm regs */ \
for (i = 0; i < MC_NTODREGS; i++) \
MCCLOCK_WRITE(dev, i, (*regs)[i]); \
\
/* reenable updates */ \
MCCLOCK_WRITE(dev, MC_REGB, \
MCCLOCK_READ(dev, MC_REGB) & ~MC_REGB_SET); \
} while (0);
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