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bd13251f AT |
1 | /* |
2 | * Copyright (C) 2014 Marvell Technology Group Ltd. | |
3 | * | |
4 | * Antoine Tenart <antoine.tenart@free-electrons.com> | |
5 | * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> | |
6 | * | |
7 | * This file is licensed under the terms of the GNU General Public | |
8 | * License version 2. This program is licensed "as is" without any | |
9 | * warranty of any kind, whether express or implied. | |
10 | */ | |
11 | ||
12 | #include <linux/delay.h> | |
13 | #include <linux/io.h> | |
aed6f3ca | 14 | #include <linux/mfd/syscon.h> |
bd13251f AT |
15 | #include <linux/module.h> |
16 | #include <linux/of.h> | |
17 | #include <linux/of_address.h> | |
18 | #include <linux/platform_device.h> | |
aed6f3ca | 19 | #include <linux/regmap.h> |
bd13251f AT |
20 | #include <linux/reset-controller.h> |
21 | #include <linux/slab.h> | |
22 | #include <linux/types.h> | |
23 | ||
24 | #define BERLIN_MAX_RESETS 32 | |
25 | ||
26 | #define to_berlin_reset_priv(p) \ | |
27 | container_of((p), struct berlin_reset_priv, rcdev) | |
28 | ||
29 | struct berlin_reset_priv { | |
30 | void __iomem *base; | |
31 | unsigned int size; | |
aed6f3ca | 32 | struct regmap *regmap; |
bd13251f AT |
33 | struct reset_controller_dev rcdev; |
34 | }; | |
35 | ||
36 | static int berlin_reset_reset(struct reset_controller_dev *rcdev, | |
37 | unsigned long id) | |
38 | { | |
39 | struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev); | |
40 | int offset = id >> 8; | |
41 | int mask = BIT(id & 0x1f); | |
42 | ||
aed6f3ca AT |
43 | if (priv->regmap) |
44 | regmap_write(priv->regmap, offset, mask); | |
45 | else | |
46 | writel(mask, priv->base + offset); | |
bd13251f AT |
47 | |
48 | /* let the reset be effective */ | |
49 | udelay(10); | |
50 | ||
51 | return 0; | |
52 | } | |
53 | ||
54 | static struct reset_control_ops berlin_reset_ops = { | |
55 | .reset = berlin_reset_reset, | |
56 | }; | |
57 | ||
58 | static int berlin_reset_xlate(struct reset_controller_dev *rcdev, | |
59 | const struct of_phandle_args *reset_spec) | |
60 | { | |
61 | struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev); | |
62 | unsigned offset, bit; | |
63 | ||
64 | if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells)) | |
65 | return -EINVAL; | |
66 | ||
67 | offset = reset_spec->args[0]; | |
68 | bit = reset_spec->args[1]; | |
69 | ||
70 | if (offset >= priv->size) | |
71 | return -EINVAL; | |
72 | ||
73 | if (bit >= BERLIN_MAX_RESETS) | |
74 | return -EINVAL; | |
75 | ||
76 | return (offset << 8) | bit; | |
77 | } | |
78 | ||
aed6f3ca AT |
79 | static int berlin2_reset_probe(struct platform_device *pdev) |
80 | { | |
81 | struct device_node *parent_np = of_get_parent(pdev->dev.of_node); | |
82 | struct berlin_reset_priv *priv; | |
83 | ||
84 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); | |
85 | if (!priv) | |
86 | return -ENOMEM; | |
87 | ||
88 | priv->regmap = syscon_node_to_regmap(parent_np); | |
89 | of_node_put(parent_np); | |
90 | if (IS_ERR(priv->regmap)) | |
91 | return PTR_ERR(priv->regmap); | |
92 | ||
93 | priv->rcdev.owner = THIS_MODULE; | |
94 | priv->rcdev.ops = &berlin_reset_ops; | |
95 | priv->rcdev.of_node = pdev->dev.of_node; | |
96 | priv->rcdev.of_reset_n_cells = 2; | |
97 | priv->rcdev.of_xlate = berlin_reset_xlate; | |
98 | ||
99 | reset_controller_register(&priv->rcdev); | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
104 | static const struct of_device_id berlin_reset_dt_match[] = { | |
105 | { .compatible = "marvell,berlin2-reset" }, | |
106 | { }, | |
107 | }; | |
108 | MODULE_DEVICE_TABLE(of, berlin_reset_dt_match); | |
109 | ||
110 | static struct platform_driver berlin_reset_driver = { | |
111 | .probe = berlin2_reset_probe, | |
112 | .driver = { | |
113 | .name = "berlin2-reset", | |
114 | .of_match_table = berlin_reset_dt_match, | |
115 | }, | |
116 | }; | |
117 | module_platform_driver(berlin_reset_driver); | |
118 | ||
119 | MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); | |
120 | MODULE_AUTHOR("Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>"); | |
121 | MODULE_DESCRIPTION("Marvell Berlin reset driver"); | |
122 | MODULE_LICENSE("GPL"); | |
123 | ||
bd13251f AT |
124 | static int __berlin_reset_init(struct device_node *np) |
125 | { | |
126 | struct berlin_reset_priv *priv; | |
127 | struct resource res; | |
128 | resource_size_t size; | |
129 | int ret; | |
130 | ||
131 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
132 | if (!priv) | |
133 | return -ENOMEM; | |
134 | ||
135 | ret = of_address_to_resource(np, 0, &res); | |
136 | if (ret) | |
137 | goto err; | |
138 | ||
139 | size = resource_size(&res); | |
140 | priv->base = ioremap(res.start, size); | |
141 | if (!priv->base) { | |
142 | ret = -ENOMEM; | |
143 | goto err; | |
144 | } | |
145 | priv->size = size; | |
146 | ||
147 | priv->rcdev.owner = THIS_MODULE; | |
148 | priv->rcdev.ops = &berlin_reset_ops; | |
149 | priv->rcdev.of_node = np; | |
150 | priv->rcdev.of_reset_n_cells = 2; | |
151 | priv->rcdev.of_xlate = berlin_reset_xlate; | |
152 | ||
153 | reset_controller_register(&priv->rcdev); | |
154 | ||
155 | return 0; | |
156 | ||
157 | err: | |
158 | kfree(priv); | |
159 | return ret; | |
160 | } | |
161 | ||
162 | static const struct of_device_id berlin_reset_of_match[] __initconst = { | |
163 | { .compatible = "marvell,berlin2-chip-ctrl" }, | |
164 | { .compatible = "marvell,berlin2cd-chip-ctrl" }, | |
165 | { .compatible = "marvell,berlin2q-chip-ctrl" }, | |
166 | { }, | |
167 | }; | |
168 | ||
169 | static int __init berlin_reset_init(void) | |
170 | { | |
171 | struct device_node *np; | |
172 | int ret; | |
173 | ||
174 | for_each_matching_node(np, berlin_reset_of_match) { | |
175 | ret = __berlin_reset_init(np); | |
176 | if (ret) | |
177 | return ret; | |
178 | } | |
179 | ||
180 | return 0; | |
181 | } | |
182 | arch_initcall(berlin_reset_init); |