u-boot/arch/arm/include/asm/arch-uniphier/debug-uart.S
Masahiro Yamada b4ad44baab ARM: UniPhier: add UART initialization routine for low-level debug
The low-level debugging functions are useful to debug the early boot
stage where the full UART driver is not available.

UniPhier SoCs need to initialize the UART port 0 to use this feature.
The initialization routine is called at the very entry of the
lowlevel_init().

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2015-01-08 23:01:56 +09:00

24 lines
554 B
ArmAsm

/*
* Copyright (C) 2014 Panasonic Corporation
* Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <linux/serial_reg.h>
#if !defined(CONFIG_DEBUG_SEMIHOSTING)
#include CONFIG_DEBUG_LL_INCLUDE
#endif
#define BAUDRATE 115200
#define DIV_ROUND(x, d) (((x) + ((d) / 2)) / (d))
#define DIVISOR DIV_ROUND(UART_CLK, 16 * BAUDRATE)
.macro init_debug_uart, ra, rb, rc
addruart \ra, \rb, \rc
mov \rb, #UART_LCR_WLEN8
strb \rb, [\ra, #0x11]
ldr \rb, =DIVISOR
str \rb, [\ra, #0x24]
.endm