1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * JZ4780 common routines
4 *
5 * Copyright (c) 2013 Imagination Technologies
6 * Author: Paul Burton <paul.burton@imgtec.com>
7 */
8
9#include <config.h>
10#include <asm/io.h>
11#include <linux/bitops.h>
12#include <mach/jz4780.h>
13
14/* WDT */
15#define WDT_TDR		0x00
16#define WDT_TCER	0x04
17#define WDT_TCNT	0x08
18#define WDT_TCSR	0x0C
19
20/* Register definition */
21#define WDT_TCSR_PRESCALE_BIT	3
22#define WDT_TCSR_PRESCALE_MASK	(0x7 << WDT_TCSR_PRESCALE_BIT)
23  #define WDT_TCSR_PRESCALE1	(0x0 << WDT_TCSR_PRESCALE_BIT)
24  #define WDT_TCSR_PRESCALE4	(0x1 << WDT_TCSR_PRESCALE_BIT)
25  #define WDT_TCSR_PRESCALE16	(0x2 << WDT_TCSR_PRESCALE_BIT)
26  #define WDT_TCSR_PRESCALE64	(0x3 << WDT_TCSR_PRESCALE_BIT)
27  #define WDT_TCSR_PRESCALE256	(0x4 << WDT_TCSR_PRESCALE_BIT)
28  #define WDT_TCSR_PRESCALE1024	(0x5 << WDT_TCSR_PRESCALE_BIT)
29#define WDT_TCSR_EXT_EN		BIT(2)
30#define WDT_TCSR_RTC_EN		BIT(1)
31#define WDT_TCSR_PCK_EN		BIT(0)
32
33#define WDT_TCER_TCEN		BIT(0)
34
35void _machine_restart(void)
36{
37	void __iomem *wdt_regs = (void __iomem *)WDT_BASE;
38
39	/* EXTAL as the timer clock input. */
40	writew(WDT_TCSR_PRESCALE1 | WDT_TCSR_EXT_EN, wdt_regs + WDT_TCSR);
41
42	/* Reset the WDT counter and timeout. */
43	writew(0, wdt_regs + WDT_TCNT);
44	writew(0, wdt_regs + WDT_TDR);
45
46	jz4780_tcu_wdt_start();
47
48	/* WDT start */
49	writeb(WDT_TCER_TCEN, wdt_regs + WDT_TCER);
50
51	for (;;)
52		;
53}
54