1/* 2 * WORK Microwave work_92105 board low level init 3 * 4 * (C) Copyright 2014 DENX Software Engineering GmbH 5 * Written-by: Albert ARIBAUD <albert.aribaud@3adev.fr> 6 * 7 * Low level init is called from SPL to set up the clocks. 8 * On entry, the LPC3250 is in Direct Run mode with all clocks 9 * running at 13 MHz; on exit, ARM clock is 208 MHz, HCLK is 10 * 104 MHz and PCLK is 13 MHz. 11 * 12 * This code must run from SRAM so that the clock changes do 13 * not prevent it from executing. 14 * 15 * SPDX-License-Identifier: GPL-2.0+ 16 */ 17 18.globl lowlevel_init 19 20lowlevel_init: 21 22 /* Set ARM, HCLK, PCLK dividers for normal mode */ 23 ldr r0, =0x0000003D 24 ldr r1, =0x40004040 25 str r0, [r1] 26 27 /* Start HCLK PLL for 208 MHz */ 28 ldr r0, =0x0001401E 29 ldr r1, =0x40004058 30 str r0, [r1] 31 32 /* wait for HCLK PLL to lock */ 331: 34 ldr r0, [r1] 35 ands r0, r0, #1 36 beq 1b 37 38 /* switch to normal mode */ 39 ldr r1, =0x40004044 40 ldr r0, [r1] 41 orr r0, #0x00000004 42 str r0, [r1] 43 44 /* Return to U-Boot via saved link register */ 45 mov pc, lr 46