u-boot/board/samsung/smdkc100/lowlevel_init.S

/*
 * Copyright (C) 2009 Samsung Electronics
 * Kyungmin Park <kyungmin.park@samsung.com>
 * Minkyu Kang <mk7.kang@samsung.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <config.h>
#include <asm/arch/cpu.h>
#include <asm/arch/power.h>

/*
 * Register usages:
 *
 * r5 has zero always
 */

	.globl lowlevel_init
lowlevel_init:
	mov	r9, lr

	/* r5 has always zero */
	mov	r5, #0

	ldr	r8, =S5PC100_GPIO_BASE

	/* Disable Watchdog */
	ldr	r0, =S5PC100_WATCHDOG_BASE		@0xEA200000
	orr	r0, r0, #0x0
	str	r5, [r0]

	/* setting SRAM */
	ldr	r0, =S5PC100_SROMC_BASE
	ldr	r1, =0x9
	str	r1, [r0]

	/* S5PC100 has 3 groups of interrupt sources */
	ldr	r0, =S5PC100_VIC0_BASE			@0xE4000000
	ldr	r1, =S5PC100_VIC1_BASE			@0xE4000000
	ldr	r2, =S5PC100_VIC2_BASE			@0xE4000000

	/* Disable all interrupts (VIC0, VIC1 and VIC2) */
	mvn	r3, #0x0
	str	r3, [r0, #0x14]				@INTENCLEAR
	str	r3, [r1, #0x14]				@INTENCLEAR
	str	r3, [r2, #0x14]				@INTENCLEAR

	/* Set all interrupts as IRQ */
	str	r5, [r0, #0xc]				@INTSELECT
	str	r5, [r1, #0xc]				@INTSELECT
	str	r5, [r2, #0xc]				@INTSELECT

	/* Pending Interrupt Clear */
	str	r5, [r0, #0xf00]			@INTADDRESS
	str	r5, [r1, #0xf00]			@INTADDRESS
	str	r5, [r2, #0xf00]			@INTADDRESS

	/* for UART */
	bl uart_asm_init

	/* for TZPC */
	bl tzpc_asm_init

1:
	mov	lr, r9
	mov	pc, lr

/*
 * system_clock_init: Initialize core clock and bus clock.
 * void system_clock_init(void)
 */
system_clock_init:
	ldr	r8, =S5PC100_CLOCK_BASE		@ 0xE0100000

	/* Set Clock divider */
	ldr	r1, =0x00011110
	str	r1, [r8, #0x304]
	ldr	r1, =0x1
	str	r1, [r8, #0x308]
	ldr	r1, =0x00011301
	str	r1, [r8, #0x300]

	/* Set Lock Time */
	ldr	r1, =0xe10			@ Locktime : 0xe10 = 3600
	str	r1, [r8, #0x000]		@ APLL_LOCK
	str	r1, [r8, #0x004]		@ MPLL_LOCK
	str	r1, [r8, #0x008]		@ EPLL_LOCK
	str	r1, [r8, #0x00C]		@ HPLL_LOCK

	/* APLL_CON */
	ldr	r1, =0x81bc0400		@ SDIV 0, PDIV 4, MDIV 444 (1332MHz)
	str	r1, [r8, #0x100]
	/* MPLL_CON */
	ldr	r1, =0x80590201		@ SDIV 1, PDIV 2, MDIV 89 (267MHz)
	str	r1, [r8, #0x104]
	/* EPLL_CON */
	ldr	r1, =0x80870303		@ SDIV 3, PDIV 3, MDIV 135 (67.5MHz)
	str	r1, [r8, #0x108]
	/* HPLL_CON */
	ldr	r1, =0x80600603
	str	r1, [r8, #0x10C]

	/* Set Source Clock */
	ldr	r1, =0x1111			@ A, M, E, HPLL Muxing
	str	r1, [r8, #0x200]		@ CLK_SRC0

	ldr	r1, =0x1000001			@ Uart Clock & CLK48M Muxing
	str	r1, [r8, #0x204]		@ CLK_SRC1

	ldr	r1, =0x9000			@ ARMCLK/4
	str	r1, [r8, #0x400]		@ CLK_OUT

	/* wait at least 200us to stablize all clock */
	mov	r2, #0x10000
1:	subs	r2, r2, #1
	bne	1b

	mov	pc, lr

/*
 * uart_asm_init: Initialize UART's pins
 */
uart_asm_init:
	mov	r0, r8
	ldr	r1, =0x22222222
	str	r1, [r0, #0x0]			@ GPA0_CON
	ldr	r1, =0x00022222
	str	r1, [r0, #0x20]			@ GPA1_CON

	mov	pc, lr

/*
 * tzpc_asm_init: Initialize TZPC
 */
tzpc_asm_init:
	ldr	r0, =0xE3800000
	mov	r1, #0x0
	str	r1, [r0]
	mov	r1, #0xff
	str	r1, [r0, #0x804]
	str	r1, [r0, #0x810]

	ldr	r0, =0xE2800000
	str	r1, [r0, #0x804]
	str	r1, [r0, #0x810]
	str	r1, [r0, #0x81C]

	ldr	r0, =0xE2900000
	str	r1, [r0, #0x804]
	str	r1, [r0, #0x810]

	mov	pc, lr