freebsd-dev/sys/isa/rtc.h
Ian Lepore b524a31593 Protect access to the AT realtime clock with its own mutex.
The mutex protecting access to the registered realtime clock should not be
overloaded to protect access to the atrtc hardware, which might not even be
the registered rtc. More importantly, the resettodr mutex needs to be
eliminated to remove locking/sleeping restrictions on clock drivers, and
that can't happen if MD code for amd64 depends on it. This change moves the
protection into what's really being protected: access to the atrtc date and
time registers.

This change also adds protection when the clock is accessed from
xentimer_settime(), which bypasses the resettodr locking.

Differential Revision:	https://reviews.freebsd.org/D11483
2017-07-12 02:42:57 +00:00

125 lines
5.0 KiB
C

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)rtc.h 7.1 (Berkeley) 5/12/91
* $FreeBSD$
*/
#ifndef _I386_ISA_RTC_H_
#define _I386_ISA_RTC_H_ 1
/*
* MC146818 RTC Register locations
*/
#define RTC_SEC 0x00 /* seconds */
#define RTC_SECALRM 0x01 /* seconds alarm */
#define RTC_MIN 0x02 /* minutes */
#define RTC_MINALRM 0x03 /* minutes alarm */
#define RTC_HRS 0x04 /* hours */
#define RTC_HRSALRM 0x05 /* hours alarm */
#define RTC_WDAY 0x06 /* week day */
#define RTC_DAY 0x07 /* day of month */
#define RTC_MONTH 0x08 /* month of year */
#define RTC_YEAR 0x09 /* month of year */
#define RTC_STATUSA 0x0a /* status register A */
#define RTCSA_TUP 0x80 /* time update, don't look now */
#define RTCSA_RESET 0x70 /* reset divider */
#define RTCSA_DIVIDER 0x20 /* divider correct for 32768 Hz */
#define RTCSA_8192 0x03 /* 8192 Hz interrupt */
#define RTCSA_4096 0x04
#define RTCSA_2048 0x05
#define RTCSA_1024 0x06 /* default for profiling */
#define RTCSA_PROF RTCSA_1024
#define RTC_PROFRATE 1024
#define RTCSA_512 0x07
#define RTCSA_256 0x08
#define RTCSA_128 0x09
#define RTCSA_NOPROF RTCSA_128
#define RTC_NOPROFRATE 128
#define RTCSA_64 0x0a
#define RTCSA_32 0x0b /* 32 Hz interrupt */
#define RTC_STATUSB 0x0b /* status register B */
#define RTCSB_DST 0x01 /* USA Daylight Savings Time enable */
#define RTCSB_24HR 0x02 /* 0 = 12 hours, 1 = 24 hours */
#define RTCSB_BCD 0x04 /* 0 = BCD, 1 = Binary coded time */
#define RTCSB_SQWE 0x08 /* 1 = output sqare wave at SQW pin */
#define RTCSB_UINTR 0x10 /* 1 = enable update-ended interrupt */
#define RTCSB_AINTR 0x20 /* 1 = enable alarm interrupt */
#define RTCSB_PINTR 0x40 /* 1 = enable periodic clock interrupt */
#define RTCSB_HALT 0x80 /* stop clock updates */
#define RTC_INTR 0x0c /* status register C (R) interrupt source */
#define RTCIR_UPDATE 0x10 /* update intr */
#define RTCIR_ALARM 0x20 /* alarm intr */
#define RTCIR_PERIOD 0x40 /* periodic intr */
#define RTCIR_INT 0x80 /* interrupt output signal */
#define RTC_STATUSD 0x0d /* status register D (R) Lost Power */
#define RTCSD_PWR 0x80 /* clock power OK */
#define RTC_DIAG 0x0e /* status register E - bios diagnostic */
#define RTCDG_BITS "\020\010clock_battery\007ROM_cksum\006config_unit\005memory_size\004fixed_disk\003invalid_time"
#define RTC_RESET 0x0f /* status register F - reset code byte */
#define RTCRS_RST 0x00 /* normal reset */
#define RTCRS_LOAD 0x04 /* load system */
#define RTC_FDISKETTE 0x10 /* diskette drive type in upper/lower nibble */
#define RTCFDT_NONE 0 /* none present */
#define RTCFDT_360K 0x10 /* 360K */
#define RTCFDT_12M 0x20 /* 1.2M */
#define RTCFDT_720K 0x30 /* 720K */
#define RTCFDT_144M 0x40 /* 1.44M */
#define RTCFDT_288M_1 0x50 /* 2.88M, some BIOSes */
#define RTCFDT_288M 0x60 /* 2.88M */
#define RTC_BASELO 0x15 /* low byte of basemem size */
#define RTC_BASEHI 0x16 /* high byte of basemem size */
#define RTC_EXTLO 0x17 /* low byte of extended mem size */
#define RTC_EXTHI 0x18 /* low byte of extended mem size */
#define RTC_CENTURY 0x32 /* current century */
#ifdef _KERNEL
extern struct mtx clock_lock;
extern struct mtx atrtc_time_lock;
extern int atrtcclock_disable;
int rtcin(int reg);
void atrtc_restore(void);
void writertc(int reg, u_char val);
void atrtc_set(struct timespec *ts);
#endif
#endif /* _I386_ISA_RTC_H_ */