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/*
* Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <asm_macros.S>
#include <uart_16550.h>
.globl console_core_init
.globl console_core_putc
.globl console_core_getc
.globl console_core_flush
/* -----------------------------------------------
* int console_core_init(unsigned long base_addr,
* unsigned int uart_clk, unsigned int baud_rate)
* Function to initialize the console without a
* C Runtime to print debug information. This
* function will be accessed by console_init and
* crash reporting.
* In: x0 - console base address
* w1 - Uart clock in Hz
* w2 - Baud rate
* Out: return 1 on success
* Clobber list : x1, x2, x3
* -----------------------------------------------
*/
func console_core_init
/* Check the input base address */
cbz x0, init_fail
/* Check baud rate and uart clock for sanity */
cbz w1, init_fail
cbz w2, init_fail
/* Program the baudrate */
/* Divisor = Uart clock / (16 * baudrate) */
lsl w2, w2, #4
udiv w2, w1, w2
and w1, w2, #0xff /* w1 = DLL */
lsr w2, w2, #8
and w2, w2, #0xff /* w2 = DLLM */
ldr w3, [x0, #UARTLCR]
orr w3, w3, #UARTLCR_DLAB
str w3, [x0, #UARTLCR] /* enable DLL, DLLM programming */
str w1, [x0, #UARTDLL] /* program DLL */
str w2, [x0, #UARTDLLM] /* program DLLM */
mov w2, #~UARTLCR_DLAB
and w3, w3, w2
str w3, [x0, #UARTLCR] /* disable DLL, DLLM programming */
/* 8n1 */
mov w3, #3
str w3, [x0, #UARTLCR]
/* no interrupt */
mov w3, #0
str w3, [x0, #UARTIER]
/* enable fifo, DMA */
mov w3, #(UARTFCR_FIFOEN | UARTFCR_DMAEN)
str w3, [x0, #UARTFCR]
/* DTR + RTS */
mov w3, #3
str w3, [x0, #UARTMCR]
mov w0, #1
init_fail:
ret
endfunc console_core_init
/* --------------------------------------------------------
* int console_core_putc(int c, unsigned int base_addr)
* Function to output a character over the console. It
* returns the character printed on success or -1 on error.
* In : w0 - character to be printed
* x1 - console base address
* Out : return -1 on error else return character.
* Clobber list : x2
* --------------------------------------------------------
*/
func console_core_putc
/* Check the input parameter */
cbz x1, putc_error
/* Prepend '\r' to '\n' */
cmp w0, #0xA
b.ne 2f
/* Check if the transmit FIFO is full */
1: ldr w2, [x1, #UARTLSR]
and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE)
cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE)
b.ne 1b
mov w2, #0xD /* '\r' */
str w2, [x1, #UARTTX]
/* Check if the transmit FIFO is full */
2: ldr w2, [x1, #UARTLSR]
and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE)
cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE)
b.ne 2b
str w0, [x1, #UARTTX]
ret
putc_error:
mov w0, #-1
ret
endfunc console_core_putc
/* ---------------------------------------------
* int console_core_getc(void)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on error.
* In : w0 - console base address
* Out : return -1 on error else return character.
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_core_getc
/* Check if the receive FIFO is empty */
1: ldr w1, [x0, #UARTLSR]
tbz w1, #UARTLSR_RDR_BIT, 1b
ldr w0, [x0, #UARTRX]
ret
getc_error:
mov w0, #-1
ret
endfunc console_core_getc
/* ---------------------------------------------
* int console_core_flush(uintptr_t base_addr)
* Function to force a write of all buffered
* data that hasn't been output.
* In : x0 - console base address
* Out : return -1 on error else return 0.
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_core_flush
/* Placeholder */
mov w0, #0
ret
endfunc console_core_flush
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