summaryrefslogtreecommitdiffstats
path: root/drivers/reset/reset-berlin.c
blob: f8b48a13cf0ba86738da958f1a42a875a9f06dfa (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
/*
 * Copyright (C) 2014 Marvell Technology Group Ltd.
 *
 * Antoine Tenart <antoine.tenart@free-electrons.com>
 * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.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/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>
#include <linux/types.h>

#define BERLIN_MAX_RESETS	32

#define to_berlin_reset_priv(p)		\
	container_of((p), struct berlin_reset_priv, rcdev)

struct berlin_reset_priv {
	void __iomem			*base;
	unsigned int			size;
	struct reset_controller_dev	rcdev;
};

static int berlin_reset_reset(struct reset_controller_dev *rcdev,
			      unsigned long id)
{
	struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
	int offset = id >> 8;
	int mask = BIT(id & 0x1f);

	writel(mask, priv->base + offset);

	/* let the reset be effective */
	udelay(10);

	return 0;
}

static struct reset_control_ops berlin_reset_ops = {
	.reset	= berlin_reset_reset,
};

static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
			      const struct of_phandle_args *reset_spec)
{
	struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
	unsigned offset, bit;

	if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
		return -EINVAL;

	offset = reset_spec->args[0];
	bit = reset_spec->args[1];

	if (offset >= priv->size)
		return -EINVAL;

	if (bit >= BERLIN_MAX_RESETS)
		return -EINVAL;

	return (offset << 8) | bit;
}

static int __berlin_reset_init(struct device_node *np)
{
	struct berlin_reset_priv *priv;
	struct resource res;
	resource_size_t size;
	int ret;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	ret = of_address_to_resource(np, 0, &res);
	if (ret)
		goto err;

	size = resource_size(&res);
	priv->base = ioremap(res.start, size);
	if (!priv->base) {
		ret = -ENOMEM;
		goto err;
	}
	priv->size = size;

	priv->rcdev.owner = THIS_MODULE;
	priv->rcdev.ops = &berlin_reset_ops;
	priv->rcdev.of_node = np;
	priv->rcdev.of_reset_n_cells = 2;
	priv->rcdev.of_xlate = berlin_reset_xlate;

	reset_controller_register(&priv->rcdev);

	return 0;

err:
	kfree(priv);
	return ret;
}

static const struct of_device_id berlin_reset_of_match[] __initconst = {
	{ .compatible = "marvell,berlin2-chip-ctrl" },
	{ .compatible = "marvell,berlin2cd-chip-ctrl" },
	{ .compatible = "marvell,berlin2q-chip-ctrl" },
	{ },
};

static int __init berlin_reset_init(void)
{
	struct device_node *np;
	int ret;

	for_each_matching_node(np, berlin_reset_of_match) {
		ret = __berlin_reset_init(np);
		if (ret)
			return ret;
	}

	return 0;
}
arch_initcall(berlin_reset_init);