freebsd-skq/sys/isa/ic/nec765.h
joerg 08cb0571ab Peter's work to work around one of the most annoying bugs in the
floppy driver (or in the hardware?).  It turned out to be caused by
spurious interrupts, right after an FDC reset.

Also major cleanup in the low-level structure, there are now functions
performing error-checks for the FDC I/O.

Submitted by:	(mostly) Peter Dufault <dufault@FreeBSD.org>
1995-01-06 15:20:00 +00:00

142 lines
6.3 KiB
C

/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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: @(#)nec765.h 7.1 (Berkeley) 5/9/91
* $Id: nec765.h,v 1.3 1994/09/17 16:56:10 davidg Exp $
*/
/*
* Nec 765 floppy disc controller definitions
*/
/* Main status register */
#define NE7_DAB 0x01 /* Diskette drive A is seeking, thus busy */
#define NE7_DBB 0x02 /* Diskette drive B is seeking, thus busy */
#define NE7_CB 0x10 /* Diskette Controller Busy */
#define NE7_NDM 0x20 /* Diskette Controller in Non Dma Mode */
#define NE7_DIO 0x40 /* Diskette Controller Data register I/O */
#define NE7_RQM 0x80 /* Diskette Controller ReQuest for Master */
/* Status register ST0 */
#define NE7_ST0BITS "\020\010invld\007abnrml\006seek_cmplt\005equ_chck\004drive_notrdy\003top_head"
#define NE7_ST0_IC 0xc0 /* interrupt completion code */
#define NE7_ST0_IC_RC 0xc0 /* terminated due to ready changed, n/a */
#define NE7_ST0_IC_IV 0x80 /* invalid command; must reset FDC */
#define NE7_ST0_IC_AT 0x40 /* abnormal termination, check error stat */
#define NE7_ST0_IC_NT 0x00 /* normal termination */
#define NE7_ST0_SE 0x20 /* seek end */
#define NE7_ST0_EC 0x10 /* equipment check, recalibrated but no trk0 */
#define NE7_ST0_NR 0x08 /* not ready (n/a) */
#define NE7_ST0_HD 0x04 /* upper head selected */
#define NE7_ST0_DR 0x03 /* drive code */
/* Status register ST1 */
#define NE7_ST1BITS "\020\010end_of_cyl\006bad_crc\005data_overrun\003sec_not_fnd\002write_protect\001no_am"
#define NE7_ST1_EN 0x80 /* end of cylinder, access past last record */
#define NE7_ST1_DE 0x20 /* data error, CRC fail in ID or data */
#define NE7_ST1_OR 0x10 /* DMA overrun, DMA failed to do i/o quickly */
#define NE7_ST1_ND 0x04 /* no data, sector not found or CRC in ID f. */
#define NE7_ST1_NW 0x02 /* not writeable, attempt to violate WP */
#define NE7_ST1_MA 0x01 /* missing address mark (in ID or data field)*/
/* Status register ST2 */
#define NE7_ST2BITS "\020\007ctrl_mrk\006bad_crc\005wrong_cyl\004scn_eq\003scn_not_fnd\002bad_cyl\001no_dam"
#define NE7_ST2_CM 0x40 /* control mark; found deleted data */
#define NE7_ST2_DD 0x20 /* data error in data field, CRC fail */
#define NE7_ST2_WC 0x10 /* wrong cylinder, ID field mismatches cmd */
#define NE7_ST2_SH 0x08 /* scan equal hit */
#define NE7_ST2_SN 0x04 /* scan not satisfied */
#define NE7_ST2_BC 0x02 /* bad cylinder, cylinder marked 0xff */
#define NE7_ST2_MD 0x01 /* missing address mark in data field */
/* Status register ST3 */
#define NE7_ST3BITS "\020\010fault\007write_protect\006drdy\005tk0\004two_side\003side_sel\002"
#define NE7_ST3_FT 0x80 /* fault; PC: n/a */
#define NE7_ST3_WP 0x40 /* write protected */
#define NE7_ST3_RD 0x20 /* ready; PC: always true */
#define NE7_ST3_T0 0x10 /* track 0 */
#define NE7_ST3_TS 0x08 /* two-sided; PC: n/a */
#define NE7_ST3_HD 0x04 /* upper head select */
#define NE7_ST3_US 0x03 /* unit select */
/* Commands */
/*
* the top three bits -- where appropriate -- are set as follows:
*
* 0x80 - MT multi-track; allow both sides to be handled in single cmd
* 0x40 - MFM modified frequency modulation; use MFM encoding
* 0x20 - SK skip; skip sectors marked as "deleted"
*/
#define NE7CMD_READTRK 0x42 /* read whole track */
#define NE7CMD_SPECIFY 3 /* specify drive parameters - requires unit
parameters byte */
#define NE7CMD_SENSED 4 /* sense drive - requires unit select byte */
#define NE7CMD_WRITE 0xc5 /* write - requires eight additional bytes */
#define NE7CMD_READ 0xe6 /* read - requires eight additional bytes */
#define NE7CMD_RECAL 7 /* recalibrate drive - requires
unit select byte */
#define NE7CMD_SENSEI 8 /* sense controller interrupt status */
#define NE7CMD_WRITEDEL 0xc9 /* write deleted data */
#define NE7CMD_READID 0x4a /* read ID field */
#define NE7CMD_READDEL 0xec /* read deleted data */
#define NE7CMD_FORMAT 0x4d /* format - requires five additional bytes */
#define NE7CMD_SEEK 0x0f /* seek drive - requires unit select byte
and new cyl byte */
#define NE7CMD_SCNEQU 0xf1 /* scan equal */
#define NE7CMD_SCNLE 0xf9 /* scan less or equal */
#define NE7CMD_SCNGE 0xfd /* scan greater or equal */
/*
* Enhanced controller commands:
*/
#define NE7CMD_VERSION 0x10 /* version (ok for all controllers) */
/*
* "specify" definitions
*
* acronyms (times are relative to a FDC clock of 8 MHz):
* srt - step rate; PC usually 3 ms
* hut - head unload time; PC usually maximum of 240 ms
* hlt - head load time; PC usually minimum of 2 ms
* nd - no DMA flag; PC usually not set (0)
*/
#define NE7_SPEC_1(srt, hut) (((16 - (srt)) << 4) | (((hut) / 16)))
#define NE7_SPEC_2(hlt, nd) (((hlt) & 0xFE) | ((nd) & 1))