linux/drivers/block/swim_asm.S
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

244 lines
4.4 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* low-level functions for the SWIM floppy controller
*
* needs assembly language because is very timing dependent
* this controller exists only on macintosh 680x0 based
*
* Copyright (C) 2004,2008 Laurent Vivier <Laurent@lvivier.info>
*
* based on Alastair Bridgewater SWIM analysis, 2001
* based on netBSD IWM driver (c) 1997, 1998 Hauke Fath.
*
* 2004-08-21 (lv) - Initial implementation
* 2008-11-05 (lv) - add get_swim_mode
*/
.equ write_data, 0x0000
.equ write_mark, 0x0200
.equ write_CRC, 0x0400
.equ write_parameter,0x0600
.equ write_phase, 0x0800
.equ write_setup, 0x0a00
.equ write_mode0, 0x0c00
.equ write_mode1, 0x0e00
.equ read_data, 0x1000
.equ read_mark, 0x1200
.equ read_error, 0x1400
.equ read_parameter, 0x1600
.equ read_phase, 0x1800
.equ read_setup, 0x1a00
.equ read_status, 0x1c00
.equ read_handshake, 0x1e00
.equ o_side, 0
.equ o_track, 1
.equ o_sector, 2
.equ o_size, 3
.equ o_crc0, 4
.equ o_crc1, 5
.equ seek_time, 30000
.equ max_retry, 40
.equ sector_size, 512
.global swim_read_sector_header
swim_read_sector_header:
link %a6, #0
moveml %d1-%d5/%a0-%a4,%sp@-
movel %a6@(0x0c), %a4
bsr mfm_read_addrmark
moveml %sp@+, %d1-%d5/%a0-%a4
unlk %a6
rts
sector_address_mark:
.byte 0xa1, 0xa1, 0xa1, 0xfe
sector_data_mark:
.byte 0xa1, 0xa1, 0xa1, 0xfb
mfm_read_addrmark:
movel %a6@(0x08), %a3
lea %a3@(read_handshake), %a2
lea %a3@(read_mark), %a3
moveq #-1, %d0
movew #seek_time, %d2
wait_header_init:
tstb %a3@(read_error - read_mark)
moveb #0x18, %a3@(write_mode0 - read_mark)
moveb #0x01, %a3@(write_mode1 - read_mark)
moveb #0x01, %a3@(write_mode0 - read_mark)
tstb %a3@(read_error - read_mark)
moveb #0x08, %a3@(write_mode1 - read_mark)
lea sector_address_mark, %a0
moveq #3, %d1
wait_addr_mark_byte:
tstb %a2@
dbmi %d2, wait_addr_mark_byte
bpl header_exit
moveb %a3@, %d3
cmpb %a0@+, %d3
dbne %d1, wait_addr_mark_byte
bne wait_header_init
moveq #max_retry, %d2
amark0: tstb %a2@
dbmi %d2, amark0
bpl signal_nonyb
moveb %a3@, %a4@(o_track)
moveq #max_retry, %d2
amark1: tstb %a2@
dbmi %d2, amark1
bpl signal_nonyb
moveb %a3@, %a4@(o_side)
moveq #max_retry, %d2
amark2: tstb %a2@
dbmi %d2, amark2
bpl signal_nonyb
moveb %a3@, %a4@(o_sector)
moveq #max_retry, %d2
amark3: tstb %a2@
dbmi %d2, amark3
bpl signal_nonyb
moveb %a3@, %a4@(o_size)
moveq #max_retry, %d2
crc0: tstb %a2@
dbmi %d2, crc0
bpl signal_nonyb
moveb %a3@, %a4@(o_crc0)
moveq #max_retry, %d2
crc1: tstb %a2@
dbmi %d2, crc1
bpl signal_nonyb
moveb %a3@, %a4@(o_crc1)
tstb %a3@(read_error - read_mark)
header_exit:
moveq #0, %d0
moveb #0x18, %a3@(write_mode0 - read_mark)
rts
signal_nonyb:
moveq #-1, %d0
moveb #0x18, %a3@(write_mode0 - read_mark)
rts
.global swim_read_sector_data
swim_read_sector_data:
link %a6, #0
moveml %d1-%d5/%a0-%a5,%sp@-
movel %a6@(0x0c), %a4
bsr mfm_read_data
moveml %sp@+, %d1-%d5/%a0-%a5
unlk %a6
rts
mfm_read_data:
movel %a6@(0x08), %a3
lea %a3@(read_handshake), %a2
lea %a3@(read_data), %a5
lea %a3@(read_mark), %a3
movew #seek_time, %d2
wait_data_init:
tstb %a3@(read_error - read_mark)
moveb #0x18, %a3@(write_mode0 - read_mark)
moveb #0x01, %a3@(write_mode1 - read_mark)
moveb #0x01, %a3@(write_mode0 - read_mark)
tstb %a3@(read_error - read_mark)
moveb #0x08, %a3@(write_mode1 - read_mark)
lea sector_data_mark, %a0
moveq #3, %d1
/* wait data address mark */
wait_data_mark_byte:
tstb %a2@
dbmi %d2, wait_data_mark_byte
bpl data_exit
moveb %a3@, %d3
cmpb %a0@+, %d3
dbne %d1, wait_data_mark_byte
bne wait_data_init
/* read data */
tstb %a3@(read_error - read_mark)
movel #sector_size-1, %d4 /* sector size */
read_new_data:
movew #max_retry, %d2
read_data_loop:
moveb %a2@, %d5
andb #0xc0, %d5
dbne %d2, read_data_loop
beq data_exit
moveb %a5@, %a4@+
andb #0x40, %d5
dbne %d4, read_new_data
beq exit_loop
moveb %a5@, %a4@+
dbra %d4, read_new_data
exit_loop:
/* read CRC */
movew #max_retry, %d2
data_crc0:
tstb %a2@
dbmi %d2, data_crc0
bpl data_exit
moveb %a3@, %d5
moveq #max_retry, %d2
data_crc1:
tstb %a2@
dbmi %d2, data_crc1
bpl data_exit
moveb %a3@, %d5
tstb %a3@(read_error - read_mark)
moveb #0x18, %a3@(write_mode0 - read_mark)
/* return number of bytes read */
movel #sector_size, %d0
addw #1, %d4
subl %d4, %d0
rts
data_exit:
moveb #0x18, %a3@(write_mode0 - read_mark)
moveq #-1, %d0
rts