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 */
timer_init(void)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