1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
|
/*
* System Control Driver
*
* Copyright (C) 2012 Freescale Semiconductor, Inc.
* Copyright (C) 2012 Linaro Ltd.
*
* Author: Dong Aisheng <dong.aisheng@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_data/syscon.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/slab.h>
static struct platform_driver syscon_driver;
static DEFINE_SPINLOCK(syscon_list_slock);
static LIST_HEAD(syscon_list);
struct syscon {
struct device_node *np;
struct regmap *regmap;
struct list_head list;
};
static struct regmap_config syscon_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
};
static struct syscon *of_syscon_register(struct device_node *np)
{
struct syscon *syscon;
struct regmap *regmap;
void __iomem *base;
int ret;
struct regmap_config syscon_config = syscon_regmap_config;
if (!of_device_is_compatible(np, "syscon"))
return ERR_PTR(-EINVAL);
syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
if (!syscon)
return ERR_PTR(-ENOMEM);
base = of_iomap(np, 0);
if (!base) {
ret = -ENOMEM;
goto err_map;
}
/* Parse the device's DT node for an endianness specification */
if (of_property_read_bool(np, "big-endian"))
syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
else if (of_property_read_bool(np, "little-endian"))
syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
regmap = regmap_init_mmio(NULL, base, &syscon_config);
if (IS_ERR(regmap)) {
pr_err("regmap init failed\n");
ret = PTR_ERR(regmap);
goto err_regmap;
}
syscon->regmap = regmap;
syscon->np = np;
spin_lock(&syscon_list_slock);
list_add_tail(&syscon->list, &syscon_list);
spin_unlock(&syscon_list_slock);
return syscon;
err_regmap:
iounmap(base);
err_map:
kfree(syscon);
return ERR_PTR(ret);
}
struct regmap *syscon_node_to_regmap(struct device_node *np)
{
struct syscon *entry, *syscon = NULL;
spin_lock(&syscon_list_slock);
list_for_each_entry(entry, &syscon_list, list)
if (entry->np == np) {
syscon = entry;
break;
}
spin_unlock(&syscon_list_slock);
if (!syscon)
syscon = of_syscon_register(np);
if (IS_ERR(syscon))
return ERR_CAST(syscon);
return syscon->regmap;
}
EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
{
struct device_node *syscon_np;
struct regmap *regmap;
syscon_np = of_find_compatible_node(NULL, NULL, s);
if (!syscon_np)
return ERR_PTR(-ENODEV);
regmap = syscon_node_to_regmap(syscon_np);
of_node_put(syscon_np);
return regmap;
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
static int syscon_match_pdevname(struct device *dev, void *data)
{
return !strcmp(dev_name(dev), (const char *)data);
}
struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
{
struct device *dev;
struct syscon *syscon;
dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
syscon_match_pdevname);
if (!dev)
return ERR_PTR(-EPROBE_DEFER);
syscon = dev_get_drvdata(dev);
return syscon->regmap;
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
const char *property)
{
struct device_node *syscon_np;
struct regmap *regmap;
if (property)
syscon_np = of_parse_phandle(np, property, 0);
else
syscon_np = np;
if (!syscon_np)
return ERR_PTR(-ENODEV);
regmap = syscon_node_to_regmap(syscon_np);
of_node_put(syscon_np);
return regmap;
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
static int syscon_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct syscon_platform_data *pdata = dev_get_platdata(dev);
struct syscon *syscon;
struct resource *res;
void __iomem *base;
syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
if (!syscon)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENOENT;
base = devm_ioremap(dev, res->start, resource_size(res));
if (!base)
return -ENOMEM;
syscon_regmap_config.max_register = res->end - res->start - 3;
if (pdata)
syscon_regmap_config.name = pdata->label;
syscon->regmap = devm_regmap_init_mmio(dev, base,
&syscon_regmap_config);
if (IS_ERR(syscon->regmap)) {
dev_err(dev, "regmap init failed\n");
return PTR_ERR(syscon->regmap);
}
platform_set_drvdata(pdev, syscon);
dev_dbg(dev, "regmap %pR registered\n", res);
return 0;
}
static const struct platform_device_id syscon_ids[] = {
{ "syscon", },
{ }
};
static struct platform_driver syscon_driver = {
.driver = {
.name = "syscon",
.owner = THIS_MODULE,
},
.probe = syscon_probe,
.id_table = syscon_ids,
};
static int __init syscon_init(void)
{
return platform_driver_register(&syscon_driver);
}
postcore_initcall(syscon_init);
static void __exit syscon_exit(void)
{
platform_driver_unregister(&syscon_driver);
}
module_exit(syscon_exit);
MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
MODULE_DESCRIPTION("System Control driver");
MODULE_LICENSE("GPL v2");
|
