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.set noreorder
.include "hwregs_a.h"
.section .text
.global _InitPadDirect
.type _InitPadDirect, @function
_InitPadDirect:
addiu $sp, -4
sw $ra, 0($sp)
lui $t0, IOBASE
# Interface setup
li $v0, 0x40 # Interface reset
sh $v0, JOY_CTRL($t0)
li $v0, 0x88 # 250kHz clock rate
sh $v0, JOY_BAUD($t0)
li $v0, 0x0d # 8-bit, no parity, x1 multiplier
sh $v0, JOY_MODE($t0)
li $v0, 0x1003 # JOY1, TX enabled
sh $v0, JOY_CTRL($t0)
jal _wait
li $v0, 1000
# Empty RX fifo
.Lempty_fifo:
lbu $v1, JOY_TXRX($t0)
lhu $v0, JOY_STAT($t0)
nop
andi $v0, 0x2
bnez $v0, .Lempty_fifo
nop
lw $ra, 0($sp)
addiu $sp, 4
jr $ra
nop
.global _PadSetPort
.type _PadSetPort, @function
_PadSetPort:
addiu $sp, -4
sw $ra, 0($sp)
lui $t0, IOBASE
beq $a0, 2, .Lstop_comms
nop
li $v0, 0x1003 # TX Enable, Joypad port select
andi $a0, 1
sll $a0, 13
or $v0, $a0 # Select port 2 if a0 is 1
sh $v0, JOY_CTRL($t0) # Set to Joypad control interface
jal _wait # Delay for analog pads (needs testing)
li $v0, 500
.Lread_empty_fifo_set: # Flush the RX FIFO just in case
lbu $v1, JOY_TXRX($t0)
lhu $v0, JOY_STAT($t0)
nop
andi $v0, 0x2
bnez $v0, .Lread_empty_fifo_set
nop
lw $ra, 0($sp)
addiu $sp, 4
jr $ra
nop
.Lstop_comms:
sh $0 , JOY_CTRL($t0)
lw $ra, 0($sp)
addiu $sp, 4
jr $ra
nop
.global _PadReadDirect
.type _PadReadDirect, @function
_PadReadDirect:
# a0 - port number
# a1 - device data buffer
# a2 - data max length
addiu $sp, -4
sw $ra, 0($sp)
lui $t0, IOBASE
li $v0, 0x1003 # TX Enable, Joypad port select
andi $a0, 1
sll $a0, 13
or $v0, $a0 # Select port 2 if a0 is 1
sh $v0, JOY_CTRL($t0) # Set to Joypad control interface
jal _wait # Delay for analog pads (needs testing)
li $v0, 310
# May cause issues with third party adapters such as Brook wireless
#.Lread_empty_fifo: # Flush the RX FIFO just in case
# lbu $v1, JOY_TXRX($t0)
# lhu $v0, JOY_STAT($t0)
# nop
# andi $v0, 0x2
# bnez $v0, .Lread_empty_fifo
# nop
jal _PadExchng # Send device check byte
li $a0, 0x01
andi $v1, $v0, 0x100 # No pad if exchange timed out
bnez $v1, .Lno_device
addiu $v0, $0 , 1
sb $v0, 0($a1)
addiu $a1, 1
jal _wait # 1st exchange needs 27microsec after ACK
li $v0, 190 # (e.g. 7 as usual + an extra 20)
jal _PadExchng # Send command byte
li $a0, 0x42
sb $v0, 0($a1)
addiu $a1, 1
addiu $a2, -2
jal _PadExchng # Send 0 for pads, 1 for multitap
move $a0, $0 # Read is usually 0x5A
addi $a3, $0 , 1
la $t1, _pad_mot_values
.Lread_loop: # Read until buffer full, or no more data
lbu $a0, 0($t1)
nop
beqz $a0, .Lskip_mot
nop
jal _PadExchng
nop
b .Ldone_exchg
addiu $t1, 1
.Lskip_mot:
jal _PadExchng # when ACK is no longer triggered
move $a0, $0
.Ldone_exchg:
sb $v0, 0($a1)
andi $v0, 0x100
bnez $v0, .Lread_end
addi $a3, 1
addiu $a2, -1
bgtz $a2, .Lread_loop
addiu $a1, 1
.Lread_end:
b .Lexit
move $v0, $a3
.Lno_device:
addiu $v0, $0 , -1
sb $v0, 0($a1)
.Lexit:
sh $0 , JOY_CTRL($t0)
lw $ra, 0($sp)
addiu $sp, 4
jr $ra
nop
.global _PadExchng
.type _PadExchng, @function
_PadExchng:
lui $t0, IOBASE
sb $a0, JOY_TXRX($t0)
nop
.Lsend_wait:
lhu $v0, JOY_STAT($t0)
nop
andi $v0, 0x4
beqz $v0, .Lsend_wait
nop
move $v1, $0
.Lwait_ack:
bgt $v1, 100, .Ltimeout
lhu $v0, JOY_STAT($t0)
nop
andi $v0, 0x202
bne $v0, 0x202, .Lwait_ack
addiu $v1, 1
b .Ldone
nop
.Ltimeout:
lbu $v0, JOY_TXRX($t0)
nop
b .Lexit_exchg
ori $v0, 0x100
.Ldone:
lhu $v1, JOY_CTRL($t0)
lbu $v0, JOY_TXRX($t0)
or $v1, 0x10
sh $v1, JOY_CTRL($t0)
.Lexit_exchg:
jr $ra
nop
.global _wait
.type _wait, @function
_wait:
addiu $v0, -1
bgtz $v0, _wait
nop
jr $ra
nop
.section .data
.global _pad_mot_values
.type _pad_mot_values, @object
_pad_mot_values:
.byte 0 # Small motor
.byte 0 # Big motor
.byte 0
.byte 0
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