Commit | Line | Data |
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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> | |
bdb0066d | 18 | #include <linux/list.h> |
87d68730 DA |
19 | #include <linux/of.h> |
20 | #include <linux/of_address.h> | |
21 | #include <linux/of_platform.h> | |
29f9b6cf | 22 | #include <linux/platform_data/syscon.h> |
87d68730 DA |
23 | #include <linux/platform_device.h> |
24 | #include <linux/regmap.h> | |
75177dee | 25 | #include <linux/mfd/syscon.h> |
bdb0066d | 26 | #include <linux/slab.h> |
87d68730 DA |
27 | |
28 | static struct platform_driver syscon_driver; | |
29 | ||
bdb0066d PD |
30 | static DEFINE_SPINLOCK(syscon_list_slock); |
31 | static LIST_HEAD(syscon_list); | |
32 | ||
87d68730 | 33 | struct syscon { |
bdb0066d | 34 | struct device_node *np; |
87d68730 | 35 | struct regmap *regmap; |
bdb0066d PD |
36 | struct list_head list; |
37 | }; | |
38 | ||
39 | static struct regmap_config syscon_regmap_config = { | |
40 | .reg_bits = 32, | |
41 | .val_bits = 32, | |
42 | .reg_stride = 4, | |
87d68730 DA |
43 | }; |
44 | ||
bdb0066d | 45 | static struct syscon *of_syscon_register(struct device_node *np) |
87d68730 | 46 | { |
bdb0066d PD |
47 | struct syscon *syscon; |
48 | struct regmap *regmap; | |
49 | void __iomem *base; | |
db2fb60c | 50 | u32 reg_io_width; |
bdb0066d PD |
51 | int ret; |
52 | struct regmap_config syscon_config = syscon_regmap_config; | |
53 | ||
54 | if (!of_device_is_compatible(np, "syscon")) | |
55 | return ERR_PTR(-EINVAL); | |
56 | ||
57 | syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); | |
58 | if (!syscon) | |
59 | return ERR_PTR(-ENOMEM); | |
60 | ||
61 | base = of_iomap(np, 0); | |
62 | if (!base) { | |
63 | ret = -ENOMEM; | |
64 | goto err_map; | |
65 | } | |
66 | ||
67 | /* Parse the device's DT node for an endianness specification */ | |
68 | if (of_property_read_bool(np, "big-endian")) | |
69 | syscon_config.val_format_endian = REGMAP_ENDIAN_BIG; | |
70 | else if (of_property_read_bool(np, "little-endian")) | |
71 | syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE; | |
72 | ||
db2fb60c DR |
73 | /* |
74 | * search for reg-io-width property in DT. If it is not provided, | |
75 | * default to 4 bytes. regmap_init_mmio will return an error if values | |
76 | * are invalid so there is no need to check them here. | |
77 | */ | |
78 | ret = of_property_read_u32(np, "reg-io-width", ®_io_width); | |
79 | if (ret) | |
80 | reg_io_width = 4; | |
81 | ||
82 | syscon_config.reg_stride = reg_io_width; | |
83 | syscon_config.val_bits = reg_io_width * 8; | |
84 | ||
bdb0066d PD |
85 | regmap = regmap_init_mmio(NULL, base, &syscon_config); |
86 | if (IS_ERR(regmap)) { | |
87 | pr_err("regmap init failed\n"); | |
88 | ret = PTR_ERR(regmap); | |
89 | goto err_regmap; | |
90 | } | |
91 | ||
92 | syscon->regmap = regmap; | |
93 | syscon->np = np; | |
94 | ||
95 | spin_lock(&syscon_list_slock); | |
96 | list_add_tail(&syscon->list, &syscon_list); | |
97 | spin_unlock(&syscon_list_slock); | |
87d68730 | 98 | |
bdb0066d PD |
99 | return syscon; |
100 | ||
101 | err_regmap: | |
102 | iounmap(base); | |
103 | err_map: | |
104 | kfree(syscon); | |
105 | return ERR_PTR(ret); | |
87d68730 DA |
106 | } |
107 | ||
108 | struct regmap *syscon_node_to_regmap(struct device_node *np) | |
109 | { | |
bdb0066d | 110 | struct syscon *entry, *syscon = NULL; |
87d68730 | 111 | |
bdb0066d | 112 | spin_lock(&syscon_list_slock); |
87d68730 | 113 | |
bdb0066d PD |
114 | list_for_each_entry(entry, &syscon_list, list) |
115 | if (entry->np == np) { | |
116 | syscon = entry; | |
117 | break; | |
118 | } | |
119 | ||
120 | spin_unlock(&syscon_list_slock); | |
121 | ||
122 | if (!syscon) | |
123 | syscon = of_syscon_register(np); | |
124 | ||
125 | if (IS_ERR(syscon)) | |
126 | return ERR_CAST(syscon); | |
87d68730 DA |
127 | |
128 | return syscon->regmap; | |
129 | } | |
130 | EXPORT_SYMBOL_GPL(syscon_node_to_regmap); | |
131 | ||
132 | struct regmap *syscon_regmap_lookup_by_compatible(const char *s) | |
133 | { | |
134 | struct device_node *syscon_np; | |
135 | struct regmap *regmap; | |
136 | ||
137 | syscon_np = of_find_compatible_node(NULL, NULL, s); | |
138 | if (!syscon_np) | |
139 | return ERR_PTR(-ENODEV); | |
140 | ||
141 | regmap = syscon_node_to_regmap(syscon_np); | |
142 | of_node_put(syscon_np); | |
143 | ||
144 | return regmap; | |
145 | } | |
146 | EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible); | |
147 | ||
5ab3a89a AS |
148 | static int syscon_match_pdevname(struct device *dev, void *data) |
149 | { | |
5ab3a89a AS |
150 | return !strcmp(dev_name(dev), (const char *)data); |
151 | } | |
152 | ||
153 | struct regmap *syscon_regmap_lookup_by_pdevname(const char *s) | |
154 | { | |
155 | struct device *dev; | |
156 | struct syscon *syscon; | |
157 | ||
158 | dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s, | |
159 | syscon_match_pdevname); | |
160 | if (!dev) | |
161 | return ERR_PTR(-EPROBE_DEFER); | |
162 | ||
163 | syscon = dev_get_drvdata(dev); | |
164 | ||
165 | return syscon->regmap; | |
166 | } | |
167 | EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname); | |
168 | ||
87d68730 DA |
169 | struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np, |
170 | const char *property) | |
171 | { | |
172 | struct device_node *syscon_np; | |
173 | struct regmap *regmap; | |
174 | ||
45330bb4 PD |
175 | if (property) |
176 | syscon_np = of_parse_phandle(np, property, 0); | |
177 | else | |
178 | syscon_np = np; | |
179 | ||
87d68730 DA |
180 | if (!syscon_np) |
181 | return ERR_PTR(-ENODEV); | |
182 | ||
183 | regmap = syscon_node_to_regmap(syscon_np); | |
184 | of_node_put(syscon_np); | |
185 | ||
186 | return regmap; | |
187 | } | |
188 | EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle); | |
189 | ||
f791be49 | 190 | static int syscon_probe(struct platform_device *pdev) |
87d68730 DA |
191 | { |
192 | struct device *dev = &pdev->dev; | |
29f9b6cf | 193 | struct syscon_platform_data *pdata = dev_get_platdata(dev); |
87d68730 | 194 | struct syscon *syscon; |
5ab3a89a | 195 | struct resource *res; |
f10111cc | 196 | void __iomem *base; |
87d68730 | 197 | |
5ab3a89a | 198 | syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL); |
87d68730 DA |
199 | if (!syscon) |
200 | return -ENOMEM; | |
201 | ||
5ab3a89a AS |
202 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
203 | if (!res) | |
204 | return -ENOENT; | |
87d68730 | 205 | |
f10111cc AS |
206 | base = devm_ioremap(dev, res->start, resource_size(res)); |
207 | if (!base) | |
5ab3a89a | 208 | return -ENOMEM; |
87d68730 | 209 | |
5ab3a89a | 210 | syscon_regmap_config.max_register = res->end - res->start - 3; |
29f9b6cf PM |
211 | if (pdata) |
212 | syscon_regmap_config.name = pdata->label; | |
f10111cc | 213 | syscon->regmap = devm_regmap_init_mmio(dev, base, |
87d68730 DA |
214 | &syscon_regmap_config); |
215 | if (IS_ERR(syscon->regmap)) { | |
216 | dev_err(dev, "regmap init failed\n"); | |
217 | return PTR_ERR(syscon->regmap); | |
218 | } | |
219 | ||
87d68730 DA |
220 | platform_set_drvdata(pdev, syscon); |
221 | ||
38d8974e | 222 | dev_dbg(dev, "regmap %pR registered\n", res); |
87d68730 DA |
223 | |
224 | return 0; | |
225 | } | |
226 | ||
5ab3a89a AS |
227 | static const struct platform_device_id syscon_ids[] = { |
228 | { "syscon", }, | |
229 | { } | |
230 | }; | |
87d68730 DA |
231 | |
232 | static struct platform_driver syscon_driver = { | |
233 | .driver = { | |
234 | .name = "syscon", | |
87d68730 DA |
235 | }, |
236 | .probe = syscon_probe, | |
5ab3a89a | 237 | .id_table = syscon_ids, |
87d68730 DA |
238 | }; |
239 | ||
240 | static int __init syscon_init(void) | |
241 | { | |
242 | return platform_driver_register(&syscon_driver); | |
243 | } | |
244 | postcore_initcall(syscon_init); | |
245 | ||
246 | static void __exit syscon_exit(void) | |
247 | { | |
248 | platform_driver_unregister(&syscon_driver); | |
249 | } | |
250 | module_exit(syscon_exit); | |
251 | ||
252 | MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>"); | |
253 | MODULE_DESCRIPTION("System Control driver"); | |
254 | MODULE_LICENSE("GPL v2"); |