1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * WORK Microwave work_92105 board low level init 4 * 5 * (C) Copyright 2014 DENX Software Engineering GmbH 6 * Written-by: Albert ARIBAUD <albert.aribaud (at) 3adev.fr> 7 * 8 * Low level init is called from SPL to set up the clocks. 9 * On entry, the LPC3250 is in Direct Run mode with all clocks 10 * running at 13 MHz; on exit, ARM clock is 208 MHz, HCLK is 11 * 104 MHz and PCLK is 13 MHz. 12 * 13 * This code must run from SRAM so that the clock changes do 14 * not prevent it from executing. 15 */ 16 17 .globl lowlevel_init 18 19 lowlevel_init: 20 21 /* Set ARM, HCLK, PCLK dividers for normal mode */ 22 ldr r0, =0x0000003D 23 ldr r1, =0x40004040 24 str r0, [r1] 25 26 /* Start HCLK PLL for 208 MHz */ 27 ldr r0, =0x0001401E 28 ldr r1, =0x40004058 29 str r0, [r1] 30 31 /* wait for HCLK PLL to lock */ 32 1: 33 ldr r0, [r1] 34 ands r0, r0, #1 35 beq 1b 36 37 /* switch to normal mode */ 38 ldr r1, =0x40004044 39 ldr r0, [r1] 40 orr r0, #0x00000004 41 str r0, [r1] 42 43 /* Return to U-Boot via saved link register */ 44 mov pc, lr 45
