summaryrefslogtreecommitdiff
path: root/drivers/power/reset/vexpress-poweroff.c
blob: 6a9bf7089373600120739f8f51829ba07344f8aa (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
151
152
153
154
155
156
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Copyright (C) 2012 ARM Limited
 */

#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/stat.h>
#include <linux/vexpress.h>

static void vexpress_reset_do(struct device *dev, const char *what)
{
	int err = -ENOENT;
	struct regmap *reg = dev_get_drvdata(dev);

	if (reg) {
		err = regmap_write(reg, 0, 0);
		if (!err)
			mdelay(1000);
	}

	dev_emerg(dev, "Unable to %s (%d)\n", what, err);
}

static struct device *vexpress_power_off_device;

static void vexpress_power_off(void)
{
	vexpress_reset_do(vexpress_power_off_device, "power off");
}

static struct device *vexpress_restart_device;

static int vexpress_restart(struct notifier_block *this, unsigned long mode,
			     void *cmd)
{
	vexpress_reset_do(vexpress_restart_device, "restart");

	return NOTIFY_DONE;
}

static struct notifier_block vexpress_restart_nb = {
	.notifier_call = vexpress_restart,
	.priority = 128,
};

static ssize_t vexpress_reset_active_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", vexpress_restart_device == dev);
}

static ssize_t vexpress_reset_active_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	long value;
	int err = kstrtol(buf, 0, &value);

	if (!err && value)
		vexpress_restart_device = dev;

	return err ? err : count;
}

DEVICE_ATTR(active, S_IRUGO | S_IWUSR, vexpress_reset_active_show,
		vexpress_reset_active_store);


enum vexpress_reset_func { FUNC_RESET, FUNC_SHUTDOWN, FUNC_REBOOT };

static const struct of_device_id vexpress_reset_of_match[] = {
	{
		.compatible = "arm,vexpress-reset",
		.data = (void *)FUNC_RESET,
	}, {
		.compatible = "arm,vexpress-shutdown",
		.data = (void *)FUNC_SHUTDOWN
	}, {
		.compatible = "arm,vexpress-reboot",
		.data = (void *)FUNC_REBOOT
	},
	{}
};

static int _vexpress_register_restart_handler(struct device *dev)
{
	int err;

	vexpress_restart_device = dev;
	err = register_restart_handler(&vexpress_restart_nb);
	if (err) {
		dev_err(dev, "cannot register restart handler (err=%d)\n", err);
		return err;
	}
	device_create_file(dev, &dev_attr_active);

	return 0;
}

static int vexpress_reset_probe(struct platform_device *pdev)
{
	const struct of_device_id *match =
			of_match_device(vexpress_reset_of_match, &pdev->dev);
	struct regmap *regmap;
	int ret = 0;

	if (!match)
		return -EINVAL;

	regmap = devm_regmap_init_vexpress_config(&pdev->dev);
	if (IS_ERR(regmap))
		return PTR_ERR(regmap);
	dev_set_drvdata(&pdev->dev, regmap);

	switch ((enum vexpress_reset_func)match->data) {
	case FUNC_SHUTDOWN:
		vexpress_power_off_device = &pdev->dev;
		pm_power_off = vexpress_power_off;
		break;
	case FUNC_RESET:
		if (!vexpress_restart_device)
			ret = _vexpress_register_restart_handler(&pdev->dev);
		break;
	case FUNC_REBOOT:
		ret = _vexpress_register_restart_handler(&pdev->dev);
		break;
	};

	return ret;
}

static struct platform_driver vexpress_reset_driver = {
	.probe = vexpress_reset_probe,
	.driver = {
		.name = "vexpress-reset",
		.of_match_table = vexpress_reset_of_match,
	},
};

static int __init vexpress_reset_init(void)
{
	return platform_driver_register(&vexpress_reset_driver);
}
device_initcall(vexpress_reset_init);