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|
.set noreorder
.include "hwregs_a.h"
.section .text
# Currently implemented serial control functions:
#
# cmd(a0) sub(a1)
# 0 0 Get serial status
# 0 1 Get control line status
# 0 2 Get serial mode
# 0 3 Get baud rate
# 0 4 Read 1 byte
# 1 1 Set serial control
# 1 2 Set serial mode
# 1 3 Set baud rate
# 1 4 Write 1 byte
# 2 0 Reset serial
# 2 1 Acknowledge serial
.global _sio_control
.type _sio_control, @function
_sio_control:
# a0 - command
# a1 - subcommand
# a2 - argument
lui $a3, IOBASE
beq $a0, $0, .Lcmd0
nop
beq $a0, 1, .Lcmd1
nop
beq $a0, 2, .Lcmd2
nop
jr $ra
nop
.Lcmd0:
beq $a1, $0, .Lcmd0arg0
nop
beq $a1, 1, .Lcmd0arg1
nop
beq $a1, 2, .Lcmd0arg2
nop
beq $a1, 3, .Lcmd0arg3
nop
beq $a1, 4, .Lcmd0arg4
nop
jr $ra
nop
.Lcmd0arg0: # Get SIO status
lhu $v0, SIO_STAT($a3)
nop
jr $ra
andi $v0, 0x3FF
.Lcmd0arg1: # Get control line status
lhu $v1, SIO_CTRL($a3)
nop
srl $v0, $v1, 1
andi $v0, 0x1
srl $v1, 4
andi $v1, 0x2
jr $ra
or $v0, $v1
.Lcmd0arg2: # Get serial mode
lhu $v0, SIO_MODE($a3)
nop
jr $ra
andi $v0, 0xFF
.Lcmd0arg3:
lui $v1, 0x1f
lhu $v0, SIO_BAUD($a3)
ori $v1, 0xa400
div $v1, $v0
nop
nop
mflo $v0
jr $ra
nop
.Lcmd0arg4: # Serial RX read
lbu $v0, SIO_TXRX($a3)
nop
jr $ra
nop
.Lcmd1:
beq $a1, 1, .Lcmd1arg1
nop
beq $a1, 2, .Lcmd1arg2
nop
beq $a1, 3, .Lcmd1arg3
nop
beq $a1, 4, .Lcmd1arg4
nop
jr $ra
nop
.Lcmd1arg1:
andi $v0, $a2, 0x1CFF
sh $a2, SIO_CTRL($a3)
jr $ra
nop
.Lcmd1arg2:
sh $a2, SIO_MODE($a3)
jr $ra
nop
.Lcmd1arg3:
lui $v0, 0x1f
ori $v0, 0xa400
divu $v0, $a2
bnez $a2, .Lgood_baud
nop
jr $ra
nop
.Lgood_baud:
mflo $v0
sh $v0, SIO_BAUD($a3)
nop
jr $ra
nop
.Lcmd1arg4:
sb $a2, SIO_TXRX($a3)
nop
jr $ra
nop
.Lcmd2:
beq $a1, $0 , .Lcmd2arg0
li $v0, 1
beq $a1, $v0, .Lcmd2arg1
nop
jr $ra
nop
.Lcmd2arg0:
li $v0, 0x40
sh $v0, SIO_CTRL($a3)
sh $0 , SIO_MODE($a3)
sh $0 , SIO_BAUD($a3)
nop
jr $ra
nop
.Lcmd2arg1:
lhu $v0, SIO_CTRL($a3)
nop
ori $v0, 0x10
sh $v0, SIO_CTRL($a3)
jr $ra
nop
|
