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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2014 MediaTek Inc.
4 */
5
6#include <linux/mfd/syscon.h>
7#include <linux/module.h>
8#include <linux/of.h>
9#include <linux/platform_device.h>
10#include <linux/regmap.h>
11#include <linux/slab.h>
12
13#include "reset.h"
14
15static inline struct mtk_clk_rst_data *to_mtk_clk_rst_data(struct reset_controller_dev *rcdev)
16{
17 return container_of(rcdev, struct mtk_clk_rst_data, rcdev);
18}
19
20static int mtk_reset_update(struct reset_controller_dev *rcdev,
21 unsigned long id, bool deassert)
22{
23 struct mtk_clk_rst_data *data = to_mtk_clk_rst_data(rcdev);
24 unsigned int val = deassert ? 0 : ~0;
25
26 return regmap_update_bits(data->regmap,
27 data->desc->rst_bank_ofs[id / RST_NR_PER_BANK],
28 BIT(id % RST_NR_PER_BANK), val);
29}
30
31static int mtk_reset_assert(struct reset_controller_dev *rcdev,
32 unsigned long id)
33{
34 return mtk_reset_update(rcdev, id, false);
35}
36
37static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
38 unsigned long id)
39{
40 return mtk_reset_update(rcdev, id, true);
41}
42
43static int mtk_reset(struct reset_controller_dev *rcdev, unsigned long id)
44{
45 int ret;
46
47 ret = mtk_reset_assert(rcdev, id);
48 if (ret)
49 return ret;
50
51 return mtk_reset_deassert(rcdev, id);
52}
53
54static int mtk_reset_update_set_clr(struct reset_controller_dev *rcdev,
55 unsigned long id, bool deassert)
56{
57 struct mtk_clk_rst_data *data = to_mtk_clk_rst_data(rcdev);
58 unsigned int deassert_ofs = deassert ? 0x4 : 0;
59
60 return regmap_write(data->regmap,
61 data->desc->rst_bank_ofs[id / RST_NR_PER_BANK] +
62 deassert_ofs,
63 BIT(id % RST_NR_PER_BANK));
64}
65
66static int mtk_reset_assert_set_clr(struct reset_controller_dev *rcdev,
67 unsigned long id)
68{
69 return mtk_reset_update_set_clr(rcdev, id, false);
70}
71
72static int mtk_reset_deassert_set_clr(struct reset_controller_dev *rcdev,
73 unsigned long id)
74{
75 return mtk_reset_update_set_clr(rcdev, id, true);
76}
77
78static int mtk_reset_set_clr(struct reset_controller_dev *rcdev,
79 unsigned long id)
80{
81 int ret;
82
83 ret = mtk_reset_assert_set_clr(rcdev, id);
84 if (ret)
85 return ret;
86 return mtk_reset_deassert_set_clr(rcdev, id);
87}
88
89static const struct reset_control_ops mtk_reset_ops = {
90 .assert = mtk_reset_assert,
91 .deassert = mtk_reset_deassert,
92 .reset = mtk_reset,
93};
94
95static const struct reset_control_ops mtk_reset_ops_set_clr = {
96 .assert = mtk_reset_assert_set_clr,
97 .deassert = mtk_reset_deassert_set_clr,
98 .reset = mtk_reset_set_clr,
99};
100
101static int reset_xlate(struct reset_controller_dev *rcdev,
102 const struct of_phandle_args *reset_spec)
103{
104 struct mtk_clk_rst_data *data = to_mtk_clk_rst_data(rcdev);
105
106 if (reset_spec->args[0] >= rcdev->nr_resets ||
107 reset_spec->args[0] >= data->desc->rst_idx_map_nr)
108 return -EINVAL;
109
110 return data->desc->rst_idx_map[reset_spec->args[0]];
111}
112
113int mtk_register_reset_controller_with_dev(struct device *dev,
114 const struct mtk_clk_rst_desc *desc)
115{
116 struct device_node *np = dev->of_node;
117 struct regmap *regmap;
118 const struct reset_control_ops *rcops = NULL;
119 struct mtk_clk_rst_data *data;
120 int ret;
121
122 if (!desc) {
123 dev_err(dev, "mtk clock reset desc is NULL\n");
124 return -EINVAL;
125 }
126
127 switch (desc->version) {
128 case MTK_RST_SIMPLE:
129 rcops = &mtk_reset_ops;
130 break;
131 case MTK_RST_SET_CLR:
132 rcops = &mtk_reset_ops_set_clr;
133 break;
134 default:
135 dev_err(dev, "Unknown reset version %d\n", desc->version);
136 return -EINVAL;
137 }
138
139 regmap = device_node_to_regmap(np);
140 if (IS_ERR(regmap)) {
141 dev_err(dev, "Cannot find regmap %pe\n", regmap);
142 return PTR_ERR(regmap);
143 }
144
145 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
146 if (!data)
147 return -ENOMEM;
148
149 data->desc = desc;
150 data->regmap = regmap;
151 data->rcdev.owner = THIS_MODULE;
152 data->rcdev.ops = rcops;
153 data->rcdev.of_node = np;
154 data->rcdev.dev = dev;
155
156 if (data->desc->rst_idx_map_nr > 0) {
157 data->rcdev.of_reset_n_cells = 1;
158 data->rcdev.nr_resets = desc->rst_idx_map_nr;
159 data->rcdev.of_xlate = reset_xlate;
160 } else {
161 data->rcdev.nr_resets = desc->rst_bank_nr * RST_NR_PER_BANK;
162 }
163
164 ret = devm_reset_controller_register(dev, &data->rcdev);
165 if (ret) {
166 dev_err(dev, "could not register reset controller: %d\n", ret);
167 return ret;
168 }
169
170 return 0;
171}
172EXPORT_SYMBOL_GPL(mtk_register_reset_controller_with_dev);
173
174MODULE_LICENSE("GPL");