tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
18static DEFINE_IDA(soc_ida);
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(serial_number, 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 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
72static 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
93static 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
102static const struct attribute_group soc_attr_group = {
103 .attrs = soc_attr,
104 .is_visible = soc_attribute_mode,
105};
106
107static void soc_release(struct device *dev)
108{
109 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
110
111 ida_simple_remove(&soc_ida, soc_dev->soc_dev_num);
112 kfree(soc_dev->dev.groups);
113 kfree(soc_dev);
114}
115
116static struct soc_device_attribute *early_soc_dev_attr;
117
118struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr)
119{
120 struct soc_device *soc_dev;
121 const struct attribute_group **soc_attr_groups;
122 int ret;
123
124 if (!soc_bus_type.p) {
125 if (early_soc_dev_attr)
126 return ERR_PTR(-EBUSY);
127 early_soc_dev_attr = soc_dev_attr;
128 return NULL;
129 }
130
131 soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
132 if (!soc_dev) {
133 ret = -ENOMEM;
134 goto out1;
135 }
136
137 soc_attr_groups = kcalloc(3, sizeof(*soc_attr_groups), GFP_KERNEL);
138 if (!soc_attr_groups) {
139 ret = -ENOMEM;
140 goto out2;
141 }
142 soc_attr_groups[0] = &soc_attr_group;
143 soc_attr_groups[1] = soc_dev_attr->custom_attr_group;
144
145 /* Fetch a unique (reclaimable) SOC ID. */
146 ret = ida_simple_get(&soc_ida, 0, 0, GFP_KERNEL);
147 if (ret < 0)
148 goto out3;
149 soc_dev->soc_dev_num = ret;
150
151 soc_dev->attr = soc_dev_attr;
152 soc_dev->dev.bus = &soc_bus_type;
153 soc_dev->dev.groups = soc_attr_groups;
154 soc_dev->dev.release = soc_release;
155
156 dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num);
157
158 ret = device_register(&soc_dev->dev);
159 if (ret) {
160 put_device(&soc_dev->dev);
161 return ERR_PTR(ret);
162 }
163
164 return soc_dev;
165
166out3:
167 kfree(soc_attr_groups);
168out2:
169 kfree(soc_dev);
170out1:
171 return ERR_PTR(ret);
172}
173EXPORT_SYMBOL_GPL(soc_device_register);
174
175/* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */
176void soc_device_unregister(struct soc_device *soc_dev)
177{
178 device_unregister(&soc_dev->dev);
179 early_soc_dev_attr = NULL;
180}
181EXPORT_SYMBOL_GPL(soc_device_unregister);
182
183static int __init soc_bus_register(void)
184{
185 int ret;
186
187 ret = bus_register(&soc_bus_type);
188 if (ret)
189 return ret;
190
191 if (early_soc_dev_attr)
192 return PTR_ERR(soc_device_register(early_soc_dev_attr));
193
194 return 0;
195}
196core_initcall(soc_bus_register);
197
198static int soc_device_match_attr(const struct soc_device_attribute *attr,
199 const struct soc_device_attribute *match)
200{
201 if (match->machine &&
202 (!attr->machine || !glob_match(match->machine, attr->machine)))
203 return 0;
204
205 if (match->family &&
206 (!attr->family || !glob_match(match->family, attr->family)))
207 return 0;
208
209 if (match->revision &&
210 (!attr->revision || !glob_match(match->revision, attr->revision)))
211 return 0;
212
213 if (match->soc_id &&
214 (!attr->soc_id || !glob_match(match->soc_id, attr->soc_id)))
215 return 0;
216
217 return 1;
218}
219
220static int soc_device_match_one(struct device *dev, void *arg)
221{
222 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
223
224 return soc_device_match_attr(soc_dev->attr, arg);
225}
226
227/*
228 * soc_device_match - identify the SoC in the machine
229 * @matches: zero-terminated array of possible matches
230 *
231 * returns the first matching entry of the argument array, or NULL
232 * if none of them match.
233 *
234 * This function is meant as a helper in place of of_match_node()
235 * in cases where either no device tree is available or the information
236 * in a device node is insufficient to identify a particular variant
237 * by its compatible strings or other properties. For new devices,
238 * the DT binding should always provide unique compatible strings
239 * that allow the use of of_match_node() instead.
240 *
241 * The calling function can use the .data entry of the
242 * soc_device_attribute to pass a structure or function pointer for
243 * each entry.
244 */
245const struct soc_device_attribute *soc_device_match(
246 const struct soc_device_attribute *matches)
247{
248 int ret = 0;
249
250 if (!matches)
251 return NULL;
252
253 while (!ret) {
254 if (!(matches->machine || matches->family ||
255 matches->revision || matches->soc_id))
256 break;
257 ret = bus_for_each_dev(&soc_bus_type, NULL, (void *)matches,
258 soc_device_match_one);
259 if (ret < 0 && early_soc_dev_attr)
260 ret = soc_device_match_attr(early_soc_dev_attr,
261 matches);
262 if (ret < 0)
263 return NULL;
264 if (!ret)
265 matches++;
266 else
267 return matches;
268 }
269 return NULL;
270}
271EXPORT_SYMBOL_GPL(soc_device_match);