aboutsummaryrefslogtreecommitdiff
path: root/drivers/reset/reset-k210.c
blob: 1b6e03522b40d2b00af35b0cf4e535ed5e3ee66c (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2020 Western Digital Corporation or its affiliates.
 */
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/delay.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <soc/canaan/k210-sysctl.h>

#include <dt-bindings/reset/k210-rst.h>

#define K210_RST_MASK	0x27FFFFFF

struct k210_rst {
	struct regmap *map;
	struct reset_controller_dev rcdev;
};

static inline struct k210_rst *
to_k210_rst(struct reset_controller_dev *rcdev)
{
	return container_of(rcdev, struct k210_rst, rcdev);
}

static inline int k210_rst_assert(struct reset_controller_dev *rcdev,
				  unsigned long id)
{
	struct k210_rst *ksr = to_k210_rst(rcdev);

	return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 1);
}

static inline int k210_rst_deassert(struct reset_controller_dev *rcdev,
				    unsigned long id)
{
	struct k210_rst *ksr = to_k210_rst(rcdev);

	return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 0);
}

static int k210_rst_reset(struct reset_controller_dev *rcdev,
			  unsigned long id)
{
	int ret;

	ret = k210_rst_assert(rcdev, id);
	if (ret == 0) {
		udelay(10);
		ret = k210_rst_deassert(rcdev, id);
	}

	return ret;
}

static int k210_rst_status(struct reset_controller_dev *rcdev,
			   unsigned long id)
{
	struct k210_rst *ksr = to_k210_rst(rcdev);
	u32 reg, bit = BIT(id);
	int ret;

	ret = regmap_read(ksr->map, K210_SYSCTL_PERI_RESET, &reg);
	if (ret)
		return ret;

	return reg & bit;
}

static int k210_rst_xlate(struct reset_controller_dev *rcdev,
			  const struct of_phandle_args *reset_spec)
{
	unsigned long id = reset_spec->args[0];

	if (!(BIT(id) & K210_RST_MASK))
		return -EINVAL;

	return id;
}

static const struct reset_control_ops k210_rst_ops = {
	.assert		= k210_rst_assert,
	.deassert	= k210_rst_deassert,
	.reset		= k210_rst_reset,
	.status		= k210_rst_status,
};

static int k210_rst_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *parent_np = of_get_parent(dev->of_node);
	struct k210_rst *ksr;

	dev_info(dev, "K210 reset controller\n");

	ksr = devm_kzalloc(dev, sizeof(*ksr), GFP_KERNEL);
	if (!ksr)
		return -ENOMEM;

	ksr->map = syscon_node_to_regmap(parent_np);
	of_node_put(parent_np);
	if (IS_ERR(ksr->map))
		return PTR_ERR(ksr->map);

	ksr->rcdev.owner = THIS_MODULE;
	ksr->rcdev.dev = dev;
	ksr->rcdev.of_node = dev->of_node;
	ksr->rcdev.ops = &k210_rst_ops;
	ksr->rcdev.nr_resets = fls(K210_RST_MASK);
	ksr->rcdev.of_reset_n_cells = 1;
	ksr->rcdev.of_xlate = k210_rst_xlate;

	return devm_reset_controller_register(dev, &ksr->rcdev);
}

static const struct of_device_id k210_rst_dt_ids[] = {
	{ .compatible = "canaan,k210-rst" },
	{ /* sentinel */ },
};

static struct platform_driver k210_rst_driver = {
	.probe	= k210_rst_probe,
	.driver = {
		.name		= "k210-rst",
		.of_match_table	= k210_rst_dt_ids,
	},
};
builtin_platform_driver(k210_rst_driver);