view target-utils/libcommon/serio.S @ 979:ebdf5afa9fb5

fc-tmsh: omr responses parsed and formatted in a readable manner
author Mychaela Falconia <falcon@ivan.Harhan.ORG>
date Thu, 10 Dec 2015 04:28:19 +0000
parents d7591faa1258
children
line wrap: on
line source

#include "ns16550.h"

@ this module implements the elementary serial I/O operations

	.text
	.code	32
	.global	serial_out
serial_out:
	ldr	r1, =uart_base
	ldr	r2, [r1]
1:	ldrb	r3, [r2, #NS16550_LSR]
	tst	r3, #NS16550_LSR_THRE
	beq	1b
	strb	r0, [r2, #NS16550_THR]
	bx	lr

	.global	serial_in_poll
serial_in_poll:
	ldr	r1, =uart_base
	ldr	r2, [r1]
	ldrb	r3, [r2, #NS16550_LSR]
	tst	r3, #NS16550_LSR_DR
	ldrneb	r0, [r2, #NS16550_RBR]
	mvneq	r0, #0
	bx	lr

	.global	serial_flush
serial_flush:
	ldr	r1, =uart_base
	ldr	r2, [r1]
1:	ldrb	r3, [r2, #NS16550_LSR]
	tst	r3, #NS16550_LSR_TEMP
	beq	1b
	bx	lr