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87d68730 DA |
1 | /* |
2 | * System Control Driver | |
3 | * | |
4 | * Copyright (C) 2012 Freescale Semiconductor, Inc. | |
5 | * Copyright (C) 2012 Linaro Ltd. | |
6 | * | |
7 | * Author: Dong Aisheng <dong.aisheng@linaro.org> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | */ | |
14 | ||
15 | #include <linux/err.h> | |
16 | #include <linux/io.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/of.h> | |
19 | #include <linux/of_address.h> | |
20 | #include <linux/of_platform.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/regmap.h> | |
23 | ||
24 | static struct platform_driver syscon_driver; | |
25 | ||
26 | struct syscon { | |
27 | struct device *dev; | |
28 | void __iomem *base; | |
29 | struct regmap *regmap; | |
30 | }; | |
31 | ||
32 | static int syscon_match(struct device *dev, void *data) | |
33 | { | |
34 | struct syscon *syscon = dev_get_drvdata(dev); | |
35 | struct device_node *dn = data; | |
36 | ||
37 | return (syscon->dev->of_node == dn) ? 1 : 0; | |
38 | } | |
39 | ||
40 | struct regmap *syscon_node_to_regmap(struct device_node *np) | |
41 | { | |
42 | struct syscon *syscon; | |
43 | struct device *dev; | |
44 | ||
45 | dev = driver_find_device(&syscon_driver.driver, NULL, np, | |
46 | syscon_match); | |
47 | if (!dev) | |
48 | return ERR_PTR(-EPROBE_DEFER); | |
49 | ||
50 | syscon = dev_get_drvdata(dev); | |
51 | ||
52 | return syscon->regmap; | |
53 | } | |
54 | EXPORT_SYMBOL_GPL(syscon_node_to_regmap); | |
55 | ||
56 | struct regmap *syscon_regmap_lookup_by_compatible(const char *s) | |
57 | { | |
58 | struct device_node *syscon_np; | |
59 | struct regmap *regmap; | |
60 | ||
61 | syscon_np = of_find_compatible_node(NULL, NULL, s); | |
62 | if (!syscon_np) | |
63 | return ERR_PTR(-ENODEV); | |
64 | ||
65 | regmap = syscon_node_to_regmap(syscon_np); | |
66 | of_node_put(syscon_np); | |
67 | ||
68 | return regmap; | |
69 | } | |
70 | EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible); | |
71 | ||
72 | struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np, | |
73 | const char *property) | |
74 | { | |
75 | struct device_node *syscon_np; | |
76 | struct regmap *regmap; | |
77 | ||
78 | syscon_np = of_parse_phandle(np, property, 0); | |
79 | if (!syscon_np) | |
80 | return ERR_PTR(-ENODEV); | |
81 | ||
82 | regmap = syscon_node_to_regmap(syscon_np); | |
83 | of_node_put(syscon_np); | |
84 | ||
85 | return regmap; | |
86 | } | |
87 | EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle); | |
88 | ||
89 | static const struct of_device_id of_syscon_match[] = { | |
90 | { .compatible = "syscon", }, | |
91 | { }, | |
92 | }; | |
93 | ||
94 | static struct regmap_config syscon_regmap_config = { | |
95 | .reg_bits = 32, | |
96 | .val_bits = 32, | |
97 | .reg_stride = 4, | |
98 | }; | |
99 | ||
100 | static int __devinit syscon_probe(struct platform_device *pdev) | |
101 | { | |
102 | struct device *dev = &pdev->dev; | |
103 | struct device_node *np = dev->of_node; | |
104 | struct syscon *syscon; | |
105 | struct resource res; | |
106 | int ret; | |
107 | ||
108 | if (!np) | |
109 | return -ENOENT; | |
110 | ||
111 | syscon = devm_kzalloc(dev, sizeof(struct syscon), | |
112 | GFP_KERNEL); | |
113 | if (!syscon) | |
114 | return -ENOMEM; | |
115 | ||
116 | syscon->base = of_iomap(np, 0); | |
117 | if (!syscon->base) | |
118 | return -EADDRNOTAVAIL; | |
119 | ||
120 | ret = of_address_to_resource(np, 0, &res); | |
121 | if (ret) | |
122 | return ret; | |
123 | ||
124 | syscon_regmap_config.max_register = res.end - res.start - 3; | |
125 | syscon->regmap = devm_regmap_init_mmio(dev, syscon->base, | |
126 | &syscon_regmap_config); | |
127 | if (IS_ERR(syscon->regmap)) { | |
128 | dev_err(dev, "regmap init failed\n"); | |
129 | return PTR_ERR(syscon->regmap); | |
130 | } | |
131 | ||
132 | syscon->dev = dev; | |
133 | platform_set_drvdata(pdev, syscon); | |
134 | ||
135 | dev_info(dev, "syscon regmap start 0x%x end 0x%x registered\n", | |
136 | res.start, res.end); | |
137 | ||
138 | return 0; | |
139 | } | |
140 | ||
141 | static int __devexit syscon_remove(struct platform_device *pdev) | |
142 | { | |
143 | struct syscon *syscon; | |
144 | ||
145 | syscon = platform_get_drvdata(pdev); | |
146 | iounmap(syscon->base); | |
147 | platform_set_drvdata(pdev, NULL); | |
148 | ||
149 | return 0; | |
150 | } | |
151 | ||
152 | static struct platform_driver syscon_driver = { | |
153 | .driver = { | |
154 | .name = "syscon", | |
155 | .owner = THIS_MODULE, | |
156 | .of_match_table = of_syscon_match, | |
157 | }, | |
158 | .probe = syscon_probe, | |
159 | .remove = __devexit_p(syscon_remove), | |
160 | }; | |
161 | ||
162 | static int __init syscon_init(void) | |
163 | { | |
164 | return platform_driver_register(&syscon_driver); | |
165 | } | |
166 | postcore_initcall(syscon_init); | |
167 | ||
168 | static void __exit syscon_exit(void) | |
169 | { | |
170 | platform_driver_unregister(&syscon_driver); | |
171 | } | |
172 | module_exit(syscon_exit); | |
173 | ||
174 | MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>"); | |
175 | MODULE_DESCRIPTION("System Control driver"); | |
176 | MODULE_LICENSE("GPL v2"); |