1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/reset/reset-oxnas.c
4 *
5 * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
6 * Copyright (C) 2014 Ma Haijun <mahaijuns@gmail.com>
7 * Copyright (C) 2009 Oxford Semiconductor Ltd
8 */
9#include <linux/err.h>
10#include <linux/init.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/reset-controller.h>
14#include <linux/slab.h>
15#include <linux/delay.h>
16#include <linux/types.h>
17#include <linux/regmap.h>
18#include <linux/mfd/syscon.h>
19
20/* Regmap offsets */
21#define RST_SET_REGOFFSET	0x34
22#define RST_CLR_REGOFFSET	0x38
23
24struct oxnas_reset {
25	struct regmap *regmap;
26	struct reset_controller_dev rcdev;
27};
28
29static int oxnas_reset_reset(struct reset_controller_dev *rcdev,
30			      unsigned long id)
31{
32	struct oxnas_reset *data =
33		container_of(rcdev, struct oxnas_reset, rcdev);
34
35	regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
36	msleep(50);
37	regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
38
39	return 0;
40}
41
42static int oxnas_reset_assert(struct reset_controller_dev *rcdev,
43			      unsigned long id)
44{
45	struct oxnas_reset *data =
46		container_of(rcdev, struct oxnas_reset, rcdev);
47
48	regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
49
50	return 0;
51}
52
53static int oxnas_reset_deassert(struct reset_controller_dev *rcdev,
54				unsigned long id)
55{
56	struct oxnas_reset *data =
57		container_of(rcdev, struct oxnas_reset, rcdev);
58
59	regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
60
61	return 0;
62}
63
64static const struct reset_control_ops oxnas_reset_ops = {
65	.reset		= oxnas_reset_reset,
66	.assert		= oxnas_reset_assert,
67	.deassert	= oxnas_reset_deassert,
68};
69
70static const struct of_device_id oxnas_reset_dt_ids[] = {
71	 { .compatible = "oxsemi,ox810se-reset", },
72	 { .compatible = "oxsemi,ox820-reset", },
73	 { /* sentinel */ },
74};
75
76static int oxnas_reset_probe(struct platform_device *pdev)
77{
78	struct oxnas_reset *data;
79	struct device *parent;
80
81	parent = pdev->dev.parent;
82	if (!parent) {
83		dev_err(&pdev->dev, "no parent\n");
84		return -ENODEV;
85	}
86
87	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
88	if (!data)
89		return -ENOMEM;
90
91	data->regmap = syscon_node_to_regmap(parent->of_node);
92	if (IS_ERR(data->regmap)) {
93		dev_err(&pdev->dev, "failed to get parent regmap\n");
94		return PTR_ERR(data->regmap);
95	}
96
97	platform_set_drvdata(pdev, data);
98
99	data->rcdev.owner = THIS_MODULE;
100	data->rcdev.nr_resets = 32;
101	data->rcdev.ops = &oxnas_reset_ops;
102	data->rcdev.of_node = pdev->dev.of_node;
103
104	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
105}
106
107static struct platform_driver oxnas_reset_driver = {
108	.probe	= oxnas_reset_probe,
109	.driver = {
110		.name		= "oxnas-reset",
111		.of_match_table	= oxnas_reset_dt_ids,
112	},
113};
114builtin_platform_driver(oxnas_reset_driver);
115