1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) ST-Ericsson SA 2011
4 *
5 * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson.
6 */
7
8 #include <linux/sysfs.h>
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>
16 #include <linux/glob.h>
17
18 static DEFINE_IDA(soc_ida);
19
20 static ssize_t soc_info_get(struct device *dev,
21 struct device_attribute *attr,
22 char *buf);
23
24 struct soc_device {
25 struct device dev;
26 struct soc_device_attribute *attr;
27 int soc_dev_num;
28 };
29
30 static struct bus_type soc_bus_type = {
31 .name = "soc",
32 };
33
34 static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL);
35 static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL);
36 static DEVICE_ATTR(serial_number, 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
soc_device_to_device(struct soc_device * soc_dev)40 struct device *soc_device_to_device(struct soc_device *soc_dev)
41 {
42 return &soc_dev->dev;
43 }
44
soc_attribute_mode(struct kobject * kobj,struct attribute * attr,int index)45 static umode_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_serial_number.attr)
62 && (soc_dev->attr->serial_number != NULL))
63 return attr->mode;
64 if ((attr == &dev_attr_soc_id.attr)
65 && (soc_dev->attr->soc_id != NULL))
66 return attr->mode;
67
68 /* Unknown or unfilled attribute. */
69 return 0;
70 }
71
soc_info_get(struct device * dev,struct device_attribute * attr,char * buf)72 static ssize_t soc_info_get(struct device *dev,
73 struct device_attribute *attr,
74 char *buf)
75 {
76 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
77
78 if (attr == &dev_attr_machine)
79 return sprintf(buf, "%s\n", soc_dev->attr->machine);
80 if (attr == &dev_attr_family)
81 return sprintf(buf, "%s\n", soc_dev->attr->family);
82 if (attr == &dev_attr_revision)
83 return sprintf(buf, "%s\n", soc_dev->attr->revision);
84 if (attr == &dev_attr_serial_number)
85 return sprintf(buf, "%s\n", soc_dev->attr->serial_number);
86 if (attr == &dev_attr_soc_id)
87 return sprintf(buf, "%s\n", soc_dev->attr->soc_id);
88
89 return -EINVAL;
90
91 }
92
93 static struct attribute *soc_attr[] = {
94 &dev_attr_machine.attr,
95 &dev_attr_family.attr,
96 &dev_attr_serial_number.attr,
97 &dev_attr_soc_id.attr,
98 &dev_attr_revision.attr,
99 NULL,
100 };
101
102 static const struct attribute_group soc_attr_group = {
103 .attrs = soc_attr,
104 .is_visible = soc_attribute_mode,
105 };
106
107 static const struct attribute_group *soc_attr_groups[] = {
108 &soc_attr_group,
109 NULL,
110 };
111
soc_release(struct device * dev)112 static void soc_release(struct device *dev)
113 {
114 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
115
116 kfree(soc_dev);
117 }
118
119 static struct soc_device_attribute *early_soc_dev_attr;
120
soc_device_register(struct soc_device_attribute * soc_dev_attr)121 struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr)
122 {
123 struct soc_device *soc_dev;
124 int ret;
125
126 if (!soc_bus_type.p) {
127 if (early_soc_dev_attr)
128 return ERR_PTR(-EBUSY);
129 early_soc_dev_attr = soc_dev_attr;
130 return NULL;
131 }
132
133 soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
134 if (!soc_dev) {
135 ret = -ENOMEM;
136 goto out1;
137 }
138
139 /* Fetch a unique (reclaimable) SOC ID. */
140 ret = ida_simple_get(&soc_ida, 0, 0, GFP_KERNEL);
141 if (ret < 0)
142 goto out2;
143 soc_dev->soc_dev_num = ret;
144
145 soc_dev->attr = soc_dev_attr;
146 soc_dev->dev.bus = &soc_bus_type;
147 soc_dev->dev.groups = soc_attr_groups;
148 soc_dev->dev.release = soc_release;
149
150 dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num);
151
152 ret = device_register(&soc_dev->dev);
153 if (ret)
154 goto out3;
155
156 return soc_dev;
157
158 out3:
159 ida_simple_remove(&soc_ida, soc_dev->soc_dev_num);
160 put_device(&soc_dev->dev);
161 soc_dev = NULL;
162 out2:
163 kfree(soc_dev);
164 out1:
165 return ERR_PTR(ret);
166 }
167 EXPORT_SYMBOL_GPL(soc_device_register);
168
169 /* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */
soc_device_unregister(struct soc_device * soc_dev)170 void soc_device_unregister(struct soc_device *soc_dev)
171 {
172 ida_simple_remove(&soc_ida, soc_dev->soc_dev_num);
173
174 device_unregister(&soc_dev->dev);
175 early_soc_dev_attr = NULL;
176 }
177 EXPORT_SYMBOL_GPL(soc_device_unregister);
178
soc_bus_register(void)179 static int __init soc_bus_register(void)
180 {
181 int ret;
182
183 ret = bus_register(&soc_bus_type);
184 if (ret)
185 return ret;
186
187 if (early_soc_dev_attr)
188 return PTR_ERR(soc_device_register(early_soc_dev_attr));
189
190 return 0;
191 }
192 core_initcall(soc_bus_register);
193
soc_device_match_attr(const struct soc_device_attribute * attr,const struct soc_device_attribute * match)194 static int soc_device_match_attr(const struct soc_device_attribute *attr,
195 const struct soc_device_attribute *match)
196 {
197 if (match->machine &&
198 (!attr->machine || !glob_match(match->machine, attr->machine)))
199 return 0;
200
201 if (match->family &&
202 (!attr->family || !glob_match(match->family, attr->family)))
203 return 0;
204
205 if (match->revision &&
206 (!attr->revision || !glob_match(match->revision, attr->revision)))
207 return 0;
208
209 if (match->soc_id &&
210 (!attr->soc_id || !glob_match(match->soc_id, attr->soc_id)))
211 return 0;
212
213 return 1;
214 }
215
soc_device_match_one(struct device * dev,void * arg)216 static int soc_device_match_one(struct device *dev, void *arg)
217 {
218 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
219
220 return soc_device_match_attr(soc_dev->attr, arg);
221 }
222
223 /*
224 * soc_device_match - identify the SoC in the machine
225 * @matches: zero-terminated array of possible matches
226 *
227 * returns the first matching entry of the argument array, or NULL
228 * if none of them match.
229 *
230 * This function is meant as a helper in place of of_match_node()
231 * in cases where either no device tree is available or the information
232 * in a device node is insufficient to identify a particular variant
233 * by its compatible strings or other properties. For new devices,
234 * the DT binding should always provide unique compatible strings
235 * that allow the use of of_match_node() instead.
236 *
237 * The calling function can use the .data entry of the
238 * soc_device_attribute to pass a structure or function pointer for
239 * each entry.
240 */
soc_device_match(const struct soc_device_attribute * matches)241 const struct soc_device_attribute *soc_device_match(
242 const struct soc_device_attribute *matches)
243 {
244 int ret = 0;
245
246 if (!matches)
247 return NULL;
248
249 while (!ret) {
250 if (!(matches->machine || matches->family ||
251 matches->revision || matches->soc_id))
252 break;
253 ret = bus_for_each_dev(&soc_bus_type, NULL, (void *)matches,
254 soc_device_match_one);
255 if (ret < 0 && early_soc_dev_attr)
256 ret = soc_device_match_attr(early_soc_dev_attr,
257 matches);
258 if (ret < 0)
259 return NULL;
260 if (!ret)
261 matches++;
262 else
263 return matches;
264 }
265 return NULL;
266 }
267 EXPORT_SYMBOL_GPL(soc_device_match);
268
