1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Hisilicon Hi6220 reset controller driver
4  *
5  * Copyright (c) 2016 Linaro Limited.
6  * Copyright (c) 2015-2016 Hisilicon Limited.
7  *
8  * Author: Feng Chen <puck.chen@hisilicon.com>
9  */
10 
11 #include <linux/io.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/bitops.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/regmap.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/reset-controller.h>
20 #include <linux/reset.h>
21 #include <linux/platform_device.h>
22 
23 #define PERIPH_ASSERT_OFFSET      0x300
24 #define PERIPH_DEASSERT_OFFSET    0x304
25 #define PERIPH_MAX_INDEX          0x509
26 
27 #define SC_MEDIA_RSTEN            0x052C
28 #define SC_MEDIA_RSTDIS           0x0530
29 #define MEDIA_MAX_INDEX           8
30 
31 #define to_reset_data(x) container_of(x, struct hi6220_reset_data, rc_dev)
32 
33 enum hi6220_reset_ctrl_type {
34 	PERIPHERAL,
35 	MEDIA,
36 };
37 
38 struct hi6220_reset_data {
39 	struct reset_controller_dev rc_dev;
40 	struct regmap *regmap;
41 };
42 
43 static int hi6220_peripheral_assert(struct reset_controller_dev *rc_dev,
44 				    unsigned long idx)
45 {
46 	struct hi6220_reset_data *data = to_reset_data(rc_dev);
47 	struct regmap *regmap = data->regmap;
48 	u32 bank = idx >> 8;
49 	u32 offset = idx & 0xff;
50 	u32 reg = PERIPH_ASSERT_OFFSET + bank * 0x10;
51 
52 	return regmap_write(regmap, reg, BIT(offset));
53 }
54 
55 static int hi6220_peripheral_deassert(struct reset_controller_dev *rc_dev,
56 				      unsigned long idx)
57 {
58 	struct hi6220_reset_data *data = to_reset_data(rc_dev);
59 	struct regmap *regmap = data->regmap;
60 	u32 bank = idx >> 8;
61 	u32 offset = idx & 0xff;
62 	u32 reg = PERIPH_DEASSERT_OFFSET + bank * 0x10;
63 
64 	return regmap_write(regmap, reg, BIT(offset));
65 }
66 
67 static const struct reset_control_ops hi6220_peripheral_reset_ops = {
68 	.assert = hi6220_peripheral_assert,
69 	.deassert = hi6220_peripheral_deassert,
70 };
71 
72 static int hi6220_media_assert(struct reset_controller_dev *rc_dev,
73 			       unsigned long idx)
74 {
75 	struct hi6220_reset_data *data = to_reset_data(rc_dev);
76 	struct regmap *regmap = data->regmap;
77 
78 	return regmap_write(regmap, SC_MEDIA_RSTEN, BIT(idx));
79 }
80 
81 static int hi6220_media_deassert(struct reset_controller_dev *rc_dev,
82 				 unsigned long idx)
83 {
84 	struct hi6220_reset_data *data = to_reset_data(rc_dev);
85 	struct regmap *regmap = data->regmap;
86 
87 	return regmap_write(regmap, SC_MEDIA_RSTDIS, BIT(idx));
88 }
89 
90 static const struct reset_control_ops hi6220_media_reset_ops = {
91 	.assert = hi6220_media_assert,
92 	.deassert = hi6220_media_deassert,
93 };
94 
95 static int hi6220_reset_probe(struct platform_device *pdev)
96 {
97 	struct device_node *np = pdev->dev.of_node;
98 	struct device *dev = &pdev->dev;
99 	enum hi6220_reset_ctrl_type type;
100 	struct hi6220_reset_data *data;
101 	struct regmap *regmap;
102 
103 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
104 	if (!data)
105 		return -ENOMEM;
106 
107 	type = (enum hi6220_reset_ctrl_type)of_device_get_match_data(dev);
108 
109 	regmap = syscon_node_to_regmap(np);
110 	if (IS_ERR(regmap)) {
111 		dev_err(dev, "failed to get reset controller regmap\n");
112 		return PTR_ERR(regmap);
113 	}
114 
115 	data->regmap = regmap;
116 	data->rc_dev.of_node = np;
117 	if (type == MEDIA) {
118 		data->rc_dev.ops = &hi6220_media_reset_ops;
119 		data->rc_dev.nr_resets = MEDIA_MAX_INDEX;
120 	} else {
121 		data->rc_dev.ops = &hi6220_peripheral_reset_ops;
122 		data->rc_dev.nr_resets = PERIPH_MAX_INDEX;
123 	}
124 
125 	return reset_controller_register(&data->rc_dev);
126 }
127 
128 static const struct of_device_id hi6220_reset_match[] = {
129 	{
130 		.compatible = "hisilicon,hi6220-sysctrl",
131 		.data = (void *)PERIPHERAL,
132 	},
133 	{
134 		.compatible = "hisilicon,hi6220-mediactrl",
135 		.data = (void *)MEDIA,
136 	},
137 	{ /* sentinel */ },
138 };
139 MODULE_DEVICE_TABLE(of, hi6220_reset_match);
140 
141 static struct platform_driver hi6220_reset_driver = {
142 	.probe = hi6220_reset_probe,
143 	.driver = {
144 		.name = "reset-hi6220",
145 		.of_match_table = hi6220_reset_match,
146 	},
147 };
148 
149 static int __init hi6220_reset_init(void)
150 {
151 	return platform_driver_register(&hi6220_reset_driver);
152 }
153 
154 postcore_initcall(hi6220_reset_init);
155 
156 MODULE_LICENSE("GPL v2");
157