blob: 6575af47f43c295bcc316f11ad63da35ce6560a6 [file] [log] [blame]
/*
* Copyright (C) 2016 Marvell International Ltd.
*
* SPDX-License-Identifier: BSD-3-Clause
* https://spdx.org/licenses
*/
#include <asm_macros.S>
#include <a3700_console.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 w2, w2, #0x3ff
ldr w3, [x0, #UART_BAUD_REG]
bic w3, w3, 0x3ff
orr w3, w3, w2
str w3, [x0, #UART_BAUD_REG]/* set baud rate divisor */
/* Set UART to default 16X scheme */
mov w3, #0
str w3, [x0, #UART_POSSR_REG]
/*
* Wait for the TX FIFO to be empty. If wait for 20ms, the TX FIFO is
* still not empty, TX FIFO will reset by all means.
*/
mov w1, #20 /* max time out 20ms */
2:
/* Check whether TX FIFO is empty */
ldr w3, [x0, #UART_STATUS_REG]
and w3, w3, #UARTLSR_TXFIFOEMPTY
cmp w3, #0
b.ne 4f
/* Delay */
mov w2, #30000
3:
sub w2, w2, #1
cmp w2, #0
b.ne 3b
/* Check whether 10ms is waited */
sub w1, w1, #1
cmp w1, #0
b.ne 2b
4:
/* Reset FIFO */
mov w3, #UART_CTRL_RXFIFO_RESET
orr w3, w3, #UART_CTRL_TXFIFO_RESET
str w3, [x0, #UART_CTRL_REG]
/* Delay */
mov w2, #2000
1:
sub w2, w2, #1
cmp w2, #0
b.ne 1b
/* No Parity, 1 Stop */
mov w3, #0
str w3, [x0, #UART_CTRL_REG]
mov w0, #1
ret
init_fail:
mov w0, #0
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, #UART_STATUS_REG]
and w2, w2, #UARTLSR_TXFIFOFULL
cmp w2, #UARTLSR_TXFIFOFULL
b.eq 1b
mov w2, #0xD /* '\r' */
str w2, [x1, #UART_TX_REG]
/* Check if the transmit FIFO is full */
2: ldr w2, [x1, #UART_STATUS_REG]
and w2, w2, #UARTLSR_TXFIFOFULL
cmp w2, #UARTLSR_TXFIFOFULL
b.eq 2b
str w0, [x1, #UART_TX_REG]
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 */
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