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/*
* Copyright (C) 2016 Marvell International Ltd.
*
* SPDX-License-Identifier: BSD-3-Clause
* https://spdx.org/licenses
*/
#include <arch.h>
#include <asm_macros.S>
#include <console_macros.S>
#include <drivers/marvell/uart/a3700_console.h>
/*
* "core" functions are low-level implementations that don't require
* writable memory and are thus safe to call in BL1 crash context.
*/
.globl console_a3700_core_putc
.globl console_a3700_core_init
.globl console_a3700_core_getc
.globl console_a3700_core_flush
.globl console_a3700_putc
.globl console_a3700_getc
.globl console_a3700_flush
/* -----------------------------------------------
* int console_a3700_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, x4
* -----------------------------------------------
*/
func console_a3700_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
/*
* Wait for the TX (THR and TSR) to be empty. If wait for 3ms, the TX FIFO is
* still not empty, TX FIFO will reset by all means.
*/
mov w4, #30 /* max time out 30 * 100 us */
2:
/* Check whether TX (THR and TSR) is empty */
ldr w3, [x0, #UART_STATUS_REG]
and w3, w3, #UARTLSR_TXEMPTY
cmp w3, #0
b.ne 4f
/* Delay */
mov w3, #60000 /* 60000 cycles of below 3 instructions on 1200 MHz CPU ~~ 100 us */
3:
sub w3, w3, #1
cmp w3, #0
b.ne 3b
/* Check whether wait timeout expired */
sub w4, w4, #1
cmp w4, #0
b.ne 2b
4:
/* Reset UART via North Bridge Peripheral */
mov_imm x4, MVEBU_NB_RESET_REG
ldr w3, [x4]
bic w3, w3, #MVEBU_NB_RESET_UART_N
str w3, [x4]
orr w3, w3, #MVEBU_NB_RESET_UART_N
str w3, [x4]
/* Reset FIFO */
mov w3, #UART_CTRL_RXFIFO_RESET
orr w3, w3, #UART_CTRL_TXFIFO_RESET
str w3, [x0, #UART_CTRL_REG]
/* Delay */
mov w3, #2000
1:
sub w3, w3, #1
cmp w3, #0
b.ne 1b
/* Program the baudrate */
/* Divisor = Round(Uartclock / (16 * baudrate)) */
lsl w2, w2, #4
add w1, w1, w2, lsr #1
udiv w2, w1, w2
and w2, w2, #0x3ff /* clear all other bits to use default clock */
str w2, [x0, #UART_BAUD_REG]/* set baud rate divisor */
/* Set UART to default 16X scheme */
mov w3, #0
str w3, [x0, #UART_POSSR_REG]
/* 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_a3700_core_init
.globl console_a3700_register
/* -----------------------------------------------
* int console_a3700_register(console_t *console,
uintptr_t base, uint32_t clk, uint32_t baud)
* Function to initialize and register a new a3700
* console. Storage passed in for the console struct
* *must* be persistent (i.e. not from the stack).
* In: x0 - UART register base address
* w1 - UART clock in Hz
* w2 - Baud rate
* x3 - pointer to empty console_t struct
* Out: return 1 on success, 0 on error
* Clobber list : x0, x1, x2, x3, x4, x6, x7, x14
* -----------------------------------------------
*/
func console_a3700_register
mov x7, x30
mov x6, x3
cbz x6, register_fail
str x0, [x6, #CONSOLE_T_BASE]
bl console_a3700_core_init
cbz x0, register_fail
mov x0, x6
mov x30, x7
finish_console_register a3700, putc=1, getc=ENABLE_CONSOLE_GETC, flush=1
register_fail:
ret x7
endfunc console_a3700_register
/* --------------------------------------------------------
* int console_a3700_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_a3700_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_a3700_core_putc
/* --------------------------------------------------------
* int console_a3700_putc(int c, console_t *console)
* 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 - pointer to console_t structure
* Out : return -1 on error else return character.
* Clobber list : x2
* --------------------------------------------------------
*/
func console_a3700_putc
ldr x1, [x1, #CONSOLE_T_BASE]
b console_a3700_core_putc
endfunc console_a3700_putc
/* ---------------------------------------------
* int console_a3700_core_getc(void)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 if no character is available.
* In : w0 - console base address
* Out : w0 - character if available, else -1
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_a3700_core_getc
/* Check if there is a pending character */
ldr w1, [x0, #UART_STATUS_REG]
and w1, w1, #UARTLSR_RXRDY
cmp w1, #UARTLSR_RXRDY
b.ne getc_no_char
ldr w0, [x0, #UART_RX_REG]
and w0, w0, #0xff
ret
getc_no_char:
mov w0, #ERROR_NO_PENDING_CHAR
ret
endfunc console_a3700_core_getc
/* ---------------------------------------------
* int console_a3700_getc(console_t *console)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on if no character is available.
* In : x0 - pointer to console_t structure
* Out : w0 - character if available, else -1
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_a3700_getc
ldr x0, [x0, #CONSOLE_T_BASE]
b console_a3700_core_getc
endfunc console_a3700_getc
/* ---------------------------------------------
* void console_a3700_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 : void.
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_a3700_core_flush
/* Wait for the TX (THR and TSR) to be empty */
1: ldr w1, [x0, #UART_STATUS_REG]
and w1, w1, #UARTLSR_TXEMPTY
cmp w1, #UARTLSR_TXEMPTY
b.ne 1b
ret
endfunc console_a3700_core_flush
/* ---------------------------------------------
* void console_a3700_flush(console_t *console)
* Function to force a write of all buffered
* data that hasn't been output.
* In : x0 - pointer to console_t structure
* Out : void.
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_a3700_flush
ldr x0, [x0, #CONSOLE_T_BASE]
b console_a3700_core_flush
endfunc console_a3700_flush
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