/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

/*

 *	IKBD 6301 interrupt routine

 *

 *	Patrice Mandin

 */

	.text

	.globl	_SDL_AtariIkbdInstall

	.globl	_SDL_AtariIkbdUninstall

	.globl	_SDL_AtariIkbd_keyboard

	.globl	_SDL_AtariIkbd_mouseb

	.globl	_SDL_AtariIkbd_mousex

	.globl	_SDL_AtariIkbd_mousey

	.globl	_SDL_AtariIkbd_joystick

	.globl	_SDL_AtariIkbd_enabled

/*--- Install our IKBD vector ---*/

_SDL_AtariIkbdInstall:

	moveml	d0-d1/a0-a1,sp@-

	| Disable interrupts

	movew	#0x2700,sr

	| Save MFP registers used for keyboard

	lea	0xfffffa00:w,a0

	btst	#6,a0@(0x09)

	sne		ikbd_ierb

	btst	#6,a0@(0x15)

	sne		ikbd_imrb

	| Set our routine

	movel	0x118:w,old_ikbd

	movel	#ikbd,0x118:w

	bset	#6,0xfffffa09:w	| IERB

	bset	#6,0xfffffa15:w	| IMRB

	| Set mouse relative mode

	moveb	#8,0xfffffc02:w

	| Reenable interrupts

	movew	#0x2300,sr

	| Interrupts done

	movew	#0xffff,_SDL_AtariIkbd_enabled

	moveml	sp@+,d0-d1/a0-a1

	rts

/*--- Uninstall our IKBD vector ---*/

_SDL_AtariIkbdUninstall:

	movel	a0,sp@-

	| Disable interrupts

	movew	#0x2700,sr

	| Restore previous MFP registers

	lea	0xfffffa00:w,a0

	bclr	#6,a0@(0x09)

	tstb	ikbd_ierb

	beqs	ikbd_restoreierb

	bset	#6,a0@(0x09)

ikbd_restoreierb:

	bclr	#6,a0@(0x15)

	tstb	ikbd_imrb

	beqs	ikbd_restoreimrb

	bset	#6,a0@(0x15)

ikbd_restoreimrb:

	movel	old_ikbd,0x118:w

	| Clear keyboard buffer

	lea	0xfffffc00:w,a0

ikbd_videbuffer:

	btst	#0,a0@

	beqs	ikbd_finbuffer

	tstb	a0@(0x02)

	bras	ikbd_videbuffer

ikbd_finbuffer:

	| Reenable interrupts

	movew	#0x2300,sr

	movel	sp@+,a0

	rts

	.bss

	.even

	.comm	ikbd_ierb,1

	.comm	ikbd_imrb,1

/*--- Our custom IKBD vector ---*/

	.text

	.even

	.ascii	"XBRA"

	.ascii	"LSDL"

	.comm	old_ikbd,4*1

ikbd:

	| Check if source is IKBD or MIDI

	btst	#0,0xfffffc00.w

	beqs	ikbd_oldmidi

	moveml	d0-d1/a0,sp@-

	moveb	0xfffffc02:w,d0

	| Joystick packet ?

	cmpb	#0xff,d0

	beqs	ikbd_yes_joystick

	| Mouse packet ?

	cmpb	#0xf8,d0

	bmis	ikbd_no_mouse

	cmpb	#0xfc,d0

	bpls	ikbd_no_mouse

	| Mouse packet, byte #1

ikbd_yes_mouse:

	andw	#3,d0

	movew	d0,_SDL_AtariIkbd_mouseb

	movel	#ikbd_mousex,0x118:w

	bras	ikbd_endit_stack

	| Joystick packet, byte #1

ikbd_yes_joystick:

	movel	#ikbd_joystick,0x118:w

	bras	ikbd_endit_stack

	| Keyboard press/release

ikbd_no_mouse:

	moveb	d0,d1

	lea		_SDL_AtariIkbd_keyboard,a0

	andw	#0x7f,d1

	tas		d0

	spl		a0@(0,d1:w)

	| End of interrupt

ikbd_endit_stack:

	moveml	sp@+,d0-d1/a0

ikbd_endit:

	bclr	#6,0xfffffa11:w

	rte

	| Call old MIDI interrupt

ikbd_oldmidi:

	movel	old_ikbd,sp@-

	rts

	| Mouse packet, byte #2

ikbd_mousex:

	| Check if source is IKBD or MIDI

	btst	#0,0xfffffc00.w

	beqs	ikbd_oldmidi

	movew	d0,sp@-

	moveb	0xfffffc02:w,d0

	extw	d0

	addw	d0,_SDL_AtariIkbd_mousex

	movew	sp@+,d0

	movel	#ikbd_mousey,0x118:w

	bras	ikbd_endit

	| Mouse packet, byte #3

ikbd_mousey:

	| Check if source is IKBD or MIDI

	btst	#0,0xfffffc00.w

	beqs	ikbd_oldmidi

	movew	d0,sp@-

	moveb	0xfffffc02:w,d0

	extw	d0

	addw	d0,_SDL_AtariIkbd_mousey

	movew	sp@+,d0

	movel	#ikbd,0x118:w

	bras	ikbd_endit

	| Joystick packet, byte #2

ikbd_joystick:

	| Check if source is IKBD or MIDI

	btst	#0,0xfffffc00.w

	beqs	ikbd_oldmidi

	moveb	0xfffffc02:w,_SDL_AtariIkbd_joystick+1

	movel	#ikbd,0x118:w

	bras	ikbd_endit

	.data

	.even

_SDL_AtariIkbd_enabled:

	.word	0

	.bss

	.even

	.comm	_SDL_AtariIkbd_keyboard,128

	.comm	_SDL_AtariIkbd_mousex,2

	.comm	_SDL_AtariIkbd_mousey,2

	.comm	_SDL_AtariIkbd_mouseb,2

	.comm	_SDL_AtariIkbd_joystick,2