u-boot/arch/arm/mach-uniphier/debug-uart/debug-uart-sld3.c
Masahiro Yamada d5cf32977f ARM: uniphier: support Debug UART
For ARM32 architecture, CONFIG_DEBUG_LL is available for early
low-level debugging (and actually UniPhier 32bit SoCs use it), but
ARM64 architecture does not support it.  Instead, CONFIG_DEBUG_UART
is available as an architecture-independent debug facility.

This commit supports it on all the UniPhier SoCs (including the new
ARMv8 SoCs), which is very useful for new SoC bringups.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-03-24 01:45:41 +09:00

31 lines
629 B
C

/*
* Copyright (C) 2016 Masahiro Yamada <yamada.masahiro@socionext.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include "../bcu/bcu-regs.h"
#include "../sc-regs.h"
#include "../sg-regs.h"
#include "debug-uart.h"
#define UNIPHIER_SLD3_UART_CLK 36864000
unsigned int uniphier_sld3_debug_uart_init(void)
{
u32 tmp;
sg_set_pinsel(64, 1, 4, 4); /* TXD0 -> TXD0 */
writel(0x24440000, BCSCR5);
tmp = readl(SC_CLKCTRL);
tmp |= SC_CLKCTRL_CEN_PERI;
writel(tmp, SC_CLKCTRL);
return DIV_ROUND_CLOSEST(UNIPHIER_SLD3_UART_CLK, 16 * CONFIG_BAUDRATE);
}