Merge tag 'nfs-for-4.10-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
[linux-2.6-block.git] / drivers / base / soc.c
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1/*
2 * Copyright (C) ST-Ericsson SA 2011
3 *
4 * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson.
5 * License terms: GNU General Public License (GPL), version 2
6 */
7
8#include <linux/sysfs.h>
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9#include <linux/init.h>
10#include <linux/stat.h>
11#include <linux/slab.h>
12#include <linux/idr.h>
13#include <linux/spinlock.h>
14#include <linux/sys_soc.h>
15#include <linux/err.h>
c97db7cc 16#include <linux/glob.h>
74d1d82c 17
3a4ffe93 18static DEFINE_IDA(soc_ida);
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19
20static ssize_t soc_info_get(struct device *dev,
21 struct device_attribute *attr,
22 char *buf);
23
24struct soc_device {
25 struct device dev;
26 struct soc_device_attribute *attr;
27 int soc_dev_num;
28};
29
30static struct bus_type soc_bus_type = {
31 .name = "soc",
32};
33
34static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL);
35static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL);
36static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL);
37static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL);
38
39struct device *soc_device_to_device(struct soc_device *soc_dev)
40{
41 return &soc_dev->dev;
42}
43
726592a9 44static umode_t soc_attribute_mode(struct kobject *kobj,
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45 struct attribute *attr,
46 int index)
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47{
48 struct device *dev = container_of(kobj, struct device, kobj);
49 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
50
51 if ((attr == &dev_attr_machine.attr)
52 && (soc_dev->attr->machine != NULL))
53 return attr->mode;
54 if ((attr == &dev_attr_family.attr)
55 && (soc_dev->attr->family != NULL))
56 return attr->mode;
57 if ((attr == &dev_attr_revision.attr)
58 && (soc_dev->attr->revision != NULL))
59 return attr->mode;
60 if ((attr == &dev_attr_soc_id.attr)
61 && (soc_dev->attr->soc_id != NULL))
2071b950 62 return attr->mode;
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63
64 /* Unknown or unfilled attribute. */
65 return 0;
66}
67
68static ssize_t soc_info_get(struct device *dev,
69 struct device_attribute *attr,
70 char *buf)
71{
72 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
73
74 if (attr == &dev_attr_machine)
75 return sprintf(buf, "%s\n", soc_dev->attr->machine);
76 if (attr == &dev_attr_family)
77 return sprintf(buf, "%s\n", soc_dev->attr->family);
78 if (attr == &dev_attr_revision)
79 return sprintf(buf, "%s\n", soc_dev->attr->revision);
80 if (attr == &dev_attr_soc_id)
81 return sprintf(buf, "%s\n", soc_dev->attr->soc_id);
82
83 return -EINVAL;
84
85}
86
87static struct attribute *soc_attr[] = {
88 &dev_attr_machine.attr,
89 &dev_attr_family.attr,
90 &dev_attr_soc_id.attr,
91 &dev_attr_revision.attr,
92 NULL,
93};
94
95static const struct attribute_group soc_attr_group = {
96 .attrs = soc_attr,
97 .is_visible = soc_attribute_mode,
98};
99
100static const struct attribute_group *soc_attr_groups[] = {
101 &soc_attr_group,
102 NULL,
103};
104
105static void soc_release(struct device *dev)
106{
107 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
108
109 kfree(soc_dev);
110}
111
112struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr)
113{
114 struct soc_device *soc_dev;
115 int ret;
116
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117 if (!soc_bus_type.p) {
118 ret = bus_register(&soc_bus_type);
119 if (ret)
120 goto out1;
121 }
122
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123 soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
124 if (!soc_dev) {
2071b950 125 ret = -ENOMEM;
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126 goto out1;
127 }
128
129 /* Fetch a unique (reclaimable) SOC ID. */
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130 ret = ida_simple_get(&soc_ida, 0, 0, GFP_KERNEL);
131 if (ret < 0)
2071b950 132 goto out2;
cfcf6a91 133 soc_dev->soc_dev_num = ret;
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134
135 soc_dev->attr = soc_dev_attr;
136 soc_dev->dev.bus = &soc_bus_type;
137 soc_dev->dev.groups = soc_attr_groups;
138 soc_dev->dev.release = soc_release;
139
140 dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num);
141
142 ret = device_register(&soc_dev->dev);
143 if (ret)
144 goto out3;
145
146 return soc_dev;
147
148out3:
cfcf6a91 149 ida_simple_remove(&soc_ida, soc_dev->soc_dev_num);
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150out2:
151 kfree(soc_dev);
152out1:
153 return ERR_PTR(ret);
154}
155
156/* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */
157void soc_device_unregister(struct soc_device *soc_dev)
158{
cfcf6a91 159 ida_simple_remove(&soc_ida, soc_dev->soc_dev_num);
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160
161 device_unregister(&soc_dev->dev);
162}
163
164static int __init soc_bus_register(void)
165{
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166 if (soc_bus_type.p)
167 return 0;
168
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169 return bus_register(&soc_bus_type);
170}
171core_initcall(soc_bus_register);
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172
173static int soc_device_match_one(struct device *dev, void *arg)
174{
175 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
176 const struct soc_device_attribute *match = arg;
177
178 if (match->machine &&
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179 (!soc_dev->attr->machine ||
180 !glob_match(match->machine, soc_dev->attr->machine)))
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181 return 0;
182
183 if (match->family &&
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184 (!soc_dev->attr->family ||
185 !glob_match(match->family, soc_dev->attr->family)))
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186 return 0;
187
188 if (match->revision &&
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189 (!soc_dev->attr->revision ||
190 !glob_match(match->revision, soc_dev->attr->revision)))
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191 return 0;
192
193 if (match->soc_id &&
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194 (!soc_dev->attr->soc_id ||
195 !glob_match(match->soc_id, soc_dev->attr->soc_id)))
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196 return 0;
197
198 return 1;
199}
200
201/*
202 * soc_device_match - identify the SoC in the machine
203 * @matches: zero-terminated array of possible matches
204 *
205 * returns the first matching entry of the argument array, or NULL
206 * if none of them match.
207 *
208 * This function is meant as a helper in place of of_match_node()
209 * in cases where either no device tree is available or the information
210 * in a device node is insufficient to identify a particular variant
211 * by its compatible strings or other properties. For new devices,
212 * the DT binding should always provide unique compatible strings
213 * that allow the use of of_match_node() instead.
214 *
215 * The calling function can use the .data entry of the
216 * soc_device_attribute to pass a structure or function pointer for
217 * each entry.
218 */
219const struct soc_device_attribute *soc_device_match(
220 const struct soc_device_attribute *matches)
221{
222 int ret = 0;
223
224 if (!matches)
225 return NULL;
226
227 while (!ret) {
228 if (!(matches->machine || matches->family ||
229 matches->revision || matches->soc_id))
230 break;
231 ret = bus_for_each_dev(&soc_bus_type, NULL, (void *)matches,
232 soc_device_match_one);
233 if (!ret)
234 matches++;
235 else
236 return matches;
237 }
238 return NULL;
239}
240EXPORT_SYMBOL_GPL(soc_device_match);