1 /* 2 * (C) Copyright 2002 3 * Sysgo Real-Time Solutions, GmbH <www.elinos.com> 4 * Marius Groeger <mgroeger@sysgo.de> 5 * 6 * (C) Copyright 2002 7 * Sysgo Real-Time Solutions, GmbH <www.elinos.com> 8 * Alex Zuepke <azu@sysgo.de> 9 * 10 * (C) Copyright 2002 11 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de> 12 * 13 * (C) Copyright 2009 14 * Ilya Yanok, Emcraft Systems Ltd, <yanok@emcraft.com> 15 * 16 * (C) Copyright 2009 DENX Software Engineering 17 * Author: John Rigby <jrigby@gmail.com> 18 * Add support for MX25 19 * 20 * SPDX-License-Identifier: GPL-2.0+ 21 */ 22 23 #include <common.h> 24 #include <asm/io.h> 25 #include <asm/arch/imx-regs.h> 26 27 /* nothing really to do with interrupts, just starts up a counter. */ 28 /* The 32KHz 32-bit timer overruns in 134217 seconds */ 29 int timer_init(void) 30 { 31 int i; 32 struct gpt_regs *gpt = (struct gpt_regs *)IMX_GPT1_BASE; 33 struct ccm_regs *ccm = (struct ccm_regs *)IMX_CCM_BASE; 34 35 /* setup GP Timer 1 */ 36 writel(GPT_CTRL_SWR, &gpt->ctrl); 37 38 writel(readl(&ccm->cgr1) | CCM_CGR1_GPT1, &ccm->cgr1); 39 40 for (i = 0; i < 100; i++) 41 writel(0, &gpt->ctrl); /* We have no udelay by now */ 42 writel(0, &gpt->pre); /* prescaler = 1 */ 43 /* Freerun Mode, 32KHz input */ 44 writel(readl(&gpt->ctrl) | GPT_CTRL_CLKSOURCE_32 | GPT_CTRL_FRR, 45 &gpt->ctrl); 46 writel(readl(&gpt->ctrl) | GPT_CTRL_TEN, &gpt->ctrl); 47 48 return 0; 49 } 50