summaryrefslogtreecommitdiff
path: root/arch/arm/mach-sunxi/sunxi.c
blob: 61d3a387f01c52f746568f7d075f92704a471ce6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
/*
 * Device Tree support for Allwinner A1X SoCs
 *
 * Copyright (C) 2012 Maxime Ripard
 *
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/io.h>
#include <linux/reboot.h>

#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/system_misc.h>

#define SUN4I_WATCHDOG_CTRL_REG		0x00
#define SUN4I_WATCHDOG_CTRL_RESTART		BIT(0)
#define SUN4I_WATCHDOG_MODE_REG		0x04
#define SUN4I_WATCHDOG_MODE_ENABLE		BIT(0)
#define SUN4I_WATCHDOG_MODE_RESET_ENABLE	BIT(1)

#define SUN6I_WATCHDOG1_IRQ_REG		0x00
#define SUN6I_WATCHDOG1_CTRL_REG	0x10
#define SUN6I_WATCHDOG1_CTRL_RESTART		BIT(0)
#define SUN6I_WATCHDOG1_CONFIG_REG	0x14
#define SUN6I_WATCHDOG1_CONFIG_RESTART		BIT(0)
#define SUN6I_WATCHDOG1_CONFIG_IRQ		BIT(1)
#define SUN6I_WATCHDOG1_MODE_REG	0x18
#define SUN6I_WATCHDOG1_MODE_ENABLE		BIT(0)

static void __iomem *wdt_base;

static void sun4i_restart(enum reboot_mode mode, const char *cmd)
{
	if (!wdt_base)
		return;

	/* Enable timer and set reset bit in the watchdog */
	writel(SUN4I_WATCHDOG_MODE_ENABLE | SUN4I_WATCHDOG_MODE_RESET_ENABLE,
	       wdt_base + SUN4I_WATCHDOG_MODE_REG);

	/*
	 * Restart the watchdog. The default (and lowest) interval
	 * value for the watchdog is 0.5s.
	 */
	writel(SUN4I_WATCHDOG_CTRL_RESTART, wdt_base + SUN4I_WATCHDOG_CTRL_REG);

	while (1) {
		mdelay(5);
		writel(SUN4I_WATCHDOG_MODE_ENABLE | SUN4I_WATCHDOG_MODE_RESET_ENABLE,
		       wdt_base + SUN4I_WATCHDOG_MODE_REG);
	}
}

static void sun6i_restart(enum reboot_mode mode, const char *cmd)
{
	if (!wdt_base)
		return;

	/* Disable interrupts */
	writel(0, wdt_base + SUN6I_WATCHDOG1_IRQ_REG);

	/* We want to disable the IRQ and just reset the whole system */
	writel(SUN6I_WATCHDOG1_CONFIG_RESTART,
		wdt_base + SUN6I_WATCHDOG1_CONFIG_REG);

	/* Enable timer. The default and lowest interval value is 0.5s */
	writel(SUN6I_WATCHDOG1_MODE_ENABLE,
		wdt_base + SUN6I_WATCHDOG1_MODE_REG);

	/* Restart the watchdog. */
	writel(SUN6I_WATCHDOG1_CTRL_RESTART,
		wdt_base + SUN6I_WATCHDOG1_CTRL_REG);

	while (1) {
		mdelay(5);
		writel(SUN6I_WATCHDOG1_MODE_ENABLE,
			wdt_base + SUN6I_WATCHDOG1_MODE_REG);
	}
}

static struct of_device_id sunxi_restart_ids[] = {
	{ .compatible = "allwinner,sun4i-wdt" },
	{ .compatible = "allwinner,sun6i-wdt" },
	{ /*sentinel*/ }
};

static void sunxi_setup_restart(void)
{
	struct device_node *np;

	np = of_find_matching_node(NULL, sunxi_restart_ids);
	if (WARN(!np, "unable to setup watchdog restart"))
		return;

	wdt_base = of_iomap(np, 0);
	WARN(!wdt_base, "failed to map watchdog base address");
}

static void __init sunxi_dt_init(void)
{
	sunxi_setup_restart();

	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
}

static const char * const sunxi_board_dt_compat[] = {
	"allwinner,sun4i-a10",
	"allwinner,sun5i-a10s",
	"allwinner,sun5i-a13",
	NULL,
};

DT_MACHINE_START(SUNXI_DT, "Allwinner A1X (Device Tree)")
	.init_machine	= sunxi_dt_init,
	.dt_compat	= sunxi_board_dt_compat,
	.restart	= sun4i_restart,
MACHINE_END

static const char * const sun6i_board_dt_compat[] = {
	"allwinner,sun6i-a31",
	NULL,
};

DT_MACHINE_START(SUN6I_DT, "Allwinner sun6i (A31) Family")
	.init_machine	= sunxi_dt_init,
	.dt_compat	= sun6i_board_dt_compat,
	.restart	= sun6i_restart,
MACHINE_END

static const char * const sun7i_board_dt_compat[] = {
	"allwinner,sun7i-a20",
	NULL,
};

DT_MACHINE_START(SUN7I_DT, "Allwinner sun7i (A20) Family")
	.init_machine	= sunxi_dt_init,
	.dt_compat	= sun7i_board_dt_compat,
	.restart	= sun4i_restart,
MACHINE_END