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