u-boot/arch/arm/mach-uniphier/debug-uart/debug-uart-ld20.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

35 lines
848 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 "../sc64-regs.h"
#include "../sg-regs.h"
#include "debug-uart.h"
#define UNIPHIER_LD20_UART_CLK 58820000
unsigned int uniphier_ld20_debug_uart_init(void)
{
u32 tmp;
sg_set_iectrl(54); /* TXD0 */
sg_set_iectrl(58); /* TXD1 */
sg_set_iectrl(90); /* TXD2 */
sg_set_iectrl(94); /* TXD3 */
sg_set_pinsel(54, 0, 8, 4); /* TXD0 -> TXD0 */
sg_set_pinsel(58, 1, 8, 4); /* SPITXD1 -> TXD1 */
sg_set_pinsel(90, 1, 8, 4); /* PC0WE -> TXD2 */
sg_set_pinsel(94, 1, 8, 4); /* PCD00 -> TXD3 */
tmp = readl(SC_CLKCTRL4);
tmp |= SC_CLKCTRL4_PERI;
writel(tmp, SC_CLKCTRL4);
return DIV_ROUND_CLOSEST(UNIPHIER_LD20_UART_CLK, 16 * CONFIG_BAUDRATE);
}