u-boot/arch/arm/mach-mvebu/armada3700/cpu.c

/*
 * Copyright (C) 2016 Stefan Roese <sr@denx.de>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <dm.h>
#include <fdtdec.h>
#include <libfdt.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/arch/cpu.h>
#include <asm/arch/soc.h>
#include <asm/armv8/mmu.h>

DECLARE_GLOBAL_DATA_PTR;

/* Armada 3700 */
#define MVEBU_GPIO_NB_REG_BASE		(MVEBU_REGISTER(0x13800))

#define MVEBU_TEST_PIN_LATCH_N		(MVEBU_GPIO_NB_REG_BASE + 0x8)
#define MVEBU_XTAL_MODE_MASK		BIT(9)
#define MVEBU_XTAL_MODE_OFFS		9
#define MVEBU_XTAL_CLOCK_25MHZ		0x0
#define MVEBU_XTAL_CLOCK_40MHZ		0x1

#define MVEBU_NB_WARM_RST_REG		(MVEBU_GPIO_NB_REG_BASE + 0x40)
#define MVEBU_NB_WARM_RST_MAGIC_NUM	0x1d1e

static struct mm_region mvebu_mem_map[] = {
	{
		/* RAM */
		.phys = 0x0UL,
		.virt = 0x0UL,
		.size = 0x80000000UL,
		.attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) |
			 PTE_BLOCK_INNER_SHARE
	},
	{
		/* SRAM, MMIO regions */
		.phys = 0xd0000000UL,
		.virt = 0xd0000000UL,
		.size = 0x02000000UL,	/* 32MiB internal registers */
		.attrs = PTE_BLOCK_MEMTYPE(MT_DEVICE_NGNRNE) |
			 PTE_BLOCK_NON_SHARE
	},
	{
		/* List terminator */
		0,
	}
};

struct mm_region *mem_map = mvebu_mem_map;

void reset_cpu(ulong ignored)
{
	/*
	 * Write magic number of 0x1d1e to North Bridge Warm Reset register
	 * to trigger warm reset
	 */
	writel(MVEBU_NB_WARM_RST_MAGIC_NUM, MVEBU_NB_WARM_RST_REG);
}

/*
 * get_ref_clk
 *
 * return: reference clock in MHz (25 or 40)
 */
u32 get_ref_clk(void)
{
	u32 regval;

	regval = (readl(MVEBU_TEST_PIN_LATCH_N) & MVEBU_XTAL_MODE_MASK) >>
		MVEBU_XTAL_MODE_OFFS;

	if (regval == MVEBU_XTAL_CLOCK_25MHZ)
		return 25;
	else
		return 40;
}