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 */
timer_init(void)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