Commit | Line | Data |
---|---|---|
74d1d82c LJ |
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> | |
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 | ||
3a4ffe93 | 18 | static DEFINE_IDA(soc_ida); |
74d1d82c LJ |
19 | static DEFINE_SPINLOCK(soc_lock); |
20 | ||
21 | static ssize_t soc_info_get(struct device *dev, | |
22 | struct device_attribute *attr, | |
23 | char *buf); | |
24 | ||
25 | struct soc_device { | |
26 | struct device dev; | |
27 | struct soc_device_attribute *attr; | |
28 | int soc_dev_num; | |
29 | }; | |
30 | ||
31 | static struct bus_type soc_bus_type = { | |
32 | .name = "soc", | |
33 | }; | |
34 | ||
35 | static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL); | |
36 | static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL); | |
37 | static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL); | |
38 | static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL); | |
39 | ||
40 | struct device *soc_device_to_device(struct soc_device *soc_dev) | |
41 | { | |
42 | return &soc_dev->dev; | |
43 | } | |
44 | ||
45 | static 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 | ||
69 | static 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 | ||
88 | static 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 | ||
96 | static const struct attribute_group soc_attr_group = { | |
97 | .attrs = soc_attr, | |
98 | .is_visible = soc_attribute_mode, | |
99 | }; | |
100 | ||
101 | static const struct attribute_group *soc_attr_groups[] = { | |
102 | &soc_attr_group, | |
103 | NULL, | |
104 | }; | |
105 | ||
106 | static 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 | ||
113 | struct 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 | ||
153 | out3: | |
154 | ida_remove(&soc_ida, soc_dev->soc_dev_num); | |
155 | out2: | |
156 | kfree(soc_dev); | |
157 | out1: | |
158 | return ERR_PTR(ret); | |
159 | } | |
160 | ||
161 | /* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */ | |
162 | void 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 | ||
169 | static int __init soc_bus_register(void) | |
170 | { | |
74d1d82c LJ |
171 | return bus_register(&soc_bus_type); |
172 | } | |
173 | core_initcall(soc_bus_register); | |
174 | ||
175 | static void __exit soc_bus_unregister(void) | |
176 | { | |
177 | ida_destroy(&soc_ida); | |
178 | ||
179 | bus_unregister(&soc_bus_type); | |
180 | } | |
181 | module_exit(soc_bus_unregister); |