blob: ba29b2e73d48936ab9a93a028abd0b0d9cd29691 [file] [log] [blame]
Lee Jones74d1d822012-02-06 11:22:22 -08001/*
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>
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/stat.h>
12#include <linux/slab.h>
13#include <linux/idr.h>
14#include <linux/spinlock.h>
15#include <linux/sys_soc.h>
16#include <linux/err.h>
17
Lee Jones3a4ffe92012-03-17 09:17:49 +000018static DEFINE_IDA(soc_ida);
Lee Jones74d1d822012-02-06 11:22:22 -080019static DEFINE_SPINLOCK(soc_lock);
20
21static ssize_t soc_info_get(struct device *dev,
22 struct device_attribute *attr,
23 char *buf);
24
25struct soc_device {
26 struct device dev;
27 struct soc_device_attribute *attr;
28 int soc_dev_num;
29};
30
31static struct bus_type soc_bus_type = {
32 .name = "soc",
33};
34
35static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL);
36static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL);
37static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL);
38static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL);
39
40struct device *soc_device_to_device(struct soc_device *soc_dev)
41{
42 return &soc_dev->dev;
43}
44
45static mode_t soc_attribute_mode(struct kobject *kobj,
46 struct attribute *attr,
47 int index)
48{
49 struct device *dev = container_of(kobj, struct device, kobj);
50 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
51
52 if ((attr == &dev_attr_machine.attr)
53 && (soc_dev->attr->machine != NULL))
54 return attr->mode;
55 if ((attr == &dev_attr_family.attr)
56 && (soc_dev->attr->family != NULL))
57 return attr->mode;
58 if ((attr == &dev_attr_revision.attr)
59 && (soc_dev->attr->revision != NULL))
60 return attr->mode;
61 if ((attr == &dev_attr_soc_id.attr)
62 && (soc_dev->attr->soc_id != NULL))
63 return attr->mode;
64
65 /* Unknown or unfilled attribute. */
66 return 0;
67}
68
69static ssize_t soc_info_get(struct device *dev,
70 struct device_attribute *attr,
71 char *buf)
72{
73 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
74
75 if (attr == &dev_attr_machine)
76 return sprintf(buf, "%s\n", soc_dev->attr->machine);
77 if (attr == &dev_attr_family)
78 return sprintf(buf, "%s\n", soc_dev->attr->family);
79 if (attr == &dev_attr_revision)
80 return sprintf(buf, "%s\n", soc_dev->attr->revision);
81 if (attr == &dev_attr_soc_id)
82 return sprintf(buf, "%s\n", soc_dev->attr->soc_id);
83
84 return -EINVAL;
85
86}
87
88static struct attribute *soc_attr[] = {
89 &dev_attr_machine.attr,
90 &dev_attr_family.attr,
91 &dev_attr_soc_id.attr,
92 &dev_attr_revision.attr,
93 NULL,
94};
95
96static const struct attribute_group soc_attr_group = {
97 .attrs = soc_attr,
98 .is_visible = soc_attribute_mode,
99};
100
101static const struct attribute_group *soc_attr_groups[] = {
102 &soc_attr_group,
103 NULL,
104};
105
106static void soc_release(struct device *dev)
107{
108 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
109
110 kfree(soc_dev);
111}
112
113struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr)
114{
115 struct soc_device *soc_dev;
116 int ret;
117
118 soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
119 if (!soc_dev) {
120 ret = -ENOMEM;
121 goto out1;
122 }
123
124 /* Fetch a unique (reclaimable) SOC ID. */
125 do {
126 if (!ida_pre_get(&soc_ida, GFP_KERNEL)) {
127 ret = -ENOMEM;
128 goto out2;
129 }
130
131 spin_lock(&soc_lock);
132 ret = ida_get_new(&soc_ida, &soc_dev->soc_dev_num);
133 spin_unlock(&soc_lock);
134
135 } while (ret == -EAGAIN);
136
137 if (ret)
138 goto out2;
139
140 soc_dev->attr = soc_dev_attr;
141 soc_dev->dev.bus = &soc_bus_type;
142 soc_dev->dev.groups = soc_attr_groups;
143 soc_dev->dev.release = soc_release;
144
145 dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num);
146
147 ret = device_register(&soc_dev->dev);
148 if (ret)
149 goto out3;
150
151 return soc_dev;
152
153out3:
154 ida_remove(&soc_ida, soc_dev->soc_dev_num);
155out2:
156 kfree(soc_dev);
157out1:
158 return ERR_PTR(ret);
159}
160
161/* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */
162void soc_device_unregister(struct soc_device *soc_dev)
163{
164 ida_remove(&soc_ida, soc_dev->soc_dev_num);
165
166 device_unregister(&soc_dev->dev);
167}
168
169static int __init soc_bus_register(void)
170{
Lee Jones74d1d822012-02-06 11:22:22 -0800171 return bus_register(&soc_bus_type);
172}
173core_initcall(soc_bus_register);
174
175static void __exit soc_bus_unregister(void)
176{
177 ida_destroy(&soc_ida);
178
179 bus_unregister(&soc_bus_type);
180}
181module_exit(soc_bus_unregister);