xref: /openbmc/linux/drivers/clk/mediatek/reset.c (revision 7cbe5cb2)
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 
to_mtk_clk_rst_data(struct reset_controller_dev * rcdev)15 static 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 
mtk_reset_update(struct reset_controller_dev * rcdev,unsigned long id,bool deassert)20 static 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 
mtk_reset_assert(struct reset_controller_dev * rcdev,unsigned long id)31 static int mtk_reset_assert(struct reset_controller_dev *rcdev,
32 			    unsigned long id)
33 {
34 	return mtk_reset_update(rcdev, id, false);
35 }
36 
mtk_reset_deassert(struct reset_controller_dev * rcdev,unsigned long id)37 static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
38 			      unsigned long id)
39 {
40 	return mtk_reset_update(rcdev, id, true);
41 }
42 
mtk_reset(struct reset_controller_dev * rcdev,unsigned long id)43 static 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 
mtk_reset_update_set_clr(struct reset_controller_dev * rcdev,unsigned long id,bool deassert)54 static 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 
mtk_reset_assert_set_clr(struct reset_controller_dev * rcdev,unsigned long id)66 static 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 
mtk_reset_deassert_set_clr(struct reset_controller_dev * rcdev,unsigned long id)72 static 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 
mtk_reset_set_clr(struct reset_controller_dev * rcdev,unsigned long id)78 static 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 
89 static const struct reset_control_ops mtk_reset_ops = {
90 	.assert = mtk_reset_assert,
91 	.deassert = mtk_reset_deassert,
92 	.reset = mtk_reset,
93 };
94 
95 static 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 
reset_xlate(struct reset_controller_dev * rcdev,const struct of_phandle_args * reset_spec)101 static 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 
mtk_register_reset_controller(struct device_node * np,const struct mtk_clk_rst_desc * desc)113 int mtk_register_reset_controller(struct device_node *np,
114 				  const struct mtk_clk_rst_desc *desc)
115 {
116 	struct regmap *regmap;
117 	const struct reset_control_ops *rcops = NULL;
118 	struct mtk_clk_rst_data *data;
119 	int ret;
120 
121 	if (!desc) {
122 		pr_err("mtk clock reset desc is NULL\n");
123 		return -EINVAL;
124 	}
125 
126 	switch (desc->version) {
127 	case MTK_RST_SIMPLE:
128 		rcops = &mtk_reset_ops;
129 		break;
130 	case MTK_RST_SET_CLR:
131 		rcops = &mtk_reset_ops_set_clr;
132 		break;
133 	default:
134 		pr_err("Unknown reset version %d\n", desc->version);
135 		return -EINVAL;
136 	}
137 
138 	regmap = device_node_to_regmap(np);
139 	if (IS_ERR(regmap)) {
140 		pr_err("Cannot find regmap for %pOF: %pe\n", np, regmap);
141 		return -EINVAL;
142 	}
143 
144 	data = kzalloc(sizeof(*data), GFP_KERNEL);
145 	if (!data)
146 		return -ENOMEM;
147 
148 	data->desc = desc;
149 	data->regmap = regmap;
150 	data->rcdev.owner = THIS_MODULE;
151 	data->rcdev.ops = rcops;
152 	data->rcdev.of_node = np;
153 
154 	if (data->desc->rst_idx_map_nr > 0) {
155 		data->rcdev.of_reset_n_cells = 1;
156 		data->rcdev.nr_resets = desc->rst_idx_map_nr;
157 		data->rcdev.of_xlate = reset_xlate;
158 	} else {
159 		data->rcdev.nr_resets = desc->rst_bank_nr * RST_NR_PER_BANK;
160 	}
161 
162 	ret = reset_controller_register(&data->rcdev);
163 	if (ret) {
164 		pr_err("could not register reset controller: %d\n", ret);
165 		kfree(data);
166 		return ret;
167 	}
168 
169 	return 0;
170 }
171 
mtk_register_reset_controller_with_dev(struct device * dev,const struct mtk_clk_rst_desc * desc)172 int mtk_register_reset_controller_with_dev(struct device *dev,
173 					   const struct mtk_clk_rst_desc *desc)
174 {
175 	struct device_node *np = dev->of_node;
176 	struct regmap *regmap;
177 	const struct reset_control_ops *rcops = NULL;
178 	struct mtk_clk_rst_data *data;
179 	int ret;
180 
181 	if (!desc) {
182 		dev_err(dev, "mtk clock reset desc is NULL\n");
183 		return -EINVAL;
184 	}
185 
186 	switch (desc->version) {
187 	case MTK_RST_SIMPLE:
188 		rcops = &mtk_reset_ops;
189 		break;
190 	case MTK_RST_SET_CLR:
191 		rcops = &mtk_reset_ops_set_clr;
192 		break;
193 	default:
194 		dev_err(dev, "Unknown reset version %d\n", desc->version);
195 		return -EINVAL;
196 	}
197 
198 	regmap = device_node_to_regmap(np);
199 	if (IS_ERR(regmap)) {
200 		dev_err(dev, "Cannot find regmap %pe\n", regmap);
201 		return -EINVAL;
202 	}
203 
204 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
205 	if (!data)
206 		return -ENOMEM;
207 
208 	data->desc = desc;
209 	data->regmap = regmap;
210 	data->rcdev.owner = THIS_MODULE;
211 	data->rcdev.ops = rcops;
212 	data->rcdev.of_node = np;
213 	data->rcdev.dev = dev;
214 
215 	if (data->desc->rst_idx_map_nr > 0) {
216 		data->rcdev.of_reset_n_cells = 1;
217 		data->rcdev.nr_resets = desc->rst_idx_map_nr;
218 		data->rcdev.of_xlate = reset_xlate;
219 	} else {
220 		data->rcdev.nr_resets = desc->rst_bank_nr * RST_NR_PER_BANK;
221 	}
222 
223 	ret = devm_reset_controller_register(dev, &data->rcdev);
224 	if (ret) {
225 		dev_err(dev, "could not register reset controller: %d\n", ret);
226 		return ret;
227 	}
228 
229 	return 0;
230 }
231 EXPORT_SYMBOL_GPL(mtk_register_reset_controller_with_dev);
232 
233 MODULE_LICENSE("GPL");
234