aboutsummaryrefslogtreecommitdiff
path: root/drivers/base/sys.c
blob: 9dff77bfe1e348a0ed3a3e4f450d192b6a4ac580 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
/*
 * sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
 *
 * Copyright (c) 2002-3 Patrick Mochel
 *               2002-3 Open Source Development Lab
 *
 * This file is released under the GPLv2
 *
 * This exports a 'system' bus type.
 * By default, a 'sys' bus gets added to the root of the system. There will
 * always be core system devices. Devices can use sysdev_register() to
 * add themselves as children of the system bus.
 */

#include <linux/sysdev.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>

#include "base.h"

#define to_sysdev(k) container_of(k, struct sys_device, kobj)
#define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)


static ssize_t
sysdev_show(struct kobject *kobj, struct attribute *attr, char *buffer)
{
	struct sys_device *sysdev = to_sysdev(kobj);
	struct sysdev_attribute *sysdev_attr = to_sysdev_attr(attr);

	if (sysdev_attr->show)
		return sysdev_attr->show(sysdev, sysdev_attr, buffer);
	return -EIO;
}


static ssize_t
sysdev_store(struct kobject *kobj, struct attribute *attr,
	     const char *buffer, size_t count)
{
	struct sys_device *sysdev = to_sysdev(kobj);
	struct sysdev_attribute *sysdev_attr = to_sysdev_attr(attr);

	if (sysdev_attr->store)
		return sysdev_attr->store(sysdev, sysdev_attr, buffer, count);
	return -EIO;
}

static const struct sysfs_ops sysfs_ops = {
	.show	= sysdev_show,
	.store	= sysdev_store,
};

static struct kobj_type ktype_sysdev = {
	.sysfs_ops	= &sysfs_ops,
};


int sysdev_create_file(struct sys_device *s, struct sysdev_attribute *a)
{
	return sysfs_create_file(&s->kobj, &a->attr);
}


void sysdev_remove_file(struct sys_device *s, struct sysdev_attribute *a)
{
	sysfs_remove_file(&s->kobj, &a->attr);
}

EXPORT_SYMBOL_GPL(sysdev_create_file);
EXPORT_SYMBOL_GPL(sysdev_remove_file);

#define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj)
#define to_sysdev_class_attr(a) container_of(a, \
	struct sysdev_class_attribute, attr)

static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
				 char *buffer)
{
	struct sysdev_class *class = to_sysdev_class(kobj);
	struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);

	if (class_attr->show)
		return class_attr->show(class, class_attr, buffer);
	return -EIO;
}

static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
				  const char *buffer, size_t count)
{
	struct sysdev_class *class = to_sysdev_class(kobj);
	struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);

	if (class_attr->store)
		return class_attr->store(class, class_attr, buffer, count);
	return -EIO;
}

static const struct sysfs_ops sysfs_class_ops = {
	.show	= sysdev_class_show,
	.store	= sysdev_class_store,
};

static struct kobj_type ktype_sysdev_class = {
	.sysfs_ops	= &sysfs_class_ops,
};

int sysdev_class_create_file(struct sysdev_class *c,
			     struct sysdev_class_attribute *a)
{
	return sysfs_create_file(&c->kset.kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_class_create_file);

void sysdev_class_remove_file(struct sysdev_class *c,
			      struct sysdev_class_attribute *a)
{
	sysfs_remove_file(&c->kset.kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_class_remove_file);

static struct kset *system_kset;

int sysdev_class_register(struct sysdev_class *cls)
{
	int retval;

	pr_debug("Registering sysdev class '%s'\n", cls->name);

	INIT_LIST_HEAD(&cls->drivers);
	memset(&cls->kset.kobj, 0x00, sizeof(struct kobject));
	cls->kset.kobj.parent = &system_kset->kobj;
	cls->kset.kobj.ktype = &ktype_sysdev_class;
	cls->kset.kobj.kset = system_kset;

	retval = kobject_set_name(&cls->kset.kobj, "%s", cls->name);
	if (retval)
		return retval;

	retval = kset_register(&cls->kset);
	if (!retval && cls->attrs)
		retval = sysfs_create_files(&cls->kset.kobj,
					    (const struct attribute **)cls->attrs);
	return retval;
}

void sysdev_class_unregister(struct sysdev_class *cls)
{
	pr_debug("Unregistering sysdev class '%s'\n",
		 kobject_name(&cls->kset.kobj));
	if (cls->attrs)
		sysfs_remove_files(&cls->kset.kobj,
				   (const struct attribute **)cls->attrs);
	kset_unregister(&cls->kset);
}

EXPORT_SYMBOL_GPL(sysdev_class_register);
EXPORT_SYMBOL_GPL(sysdev_class_unregister);

static DEFINE_MUTEX(sysdev_drivers_lock);

/*
 * @dev != NULL means that we're unwinding because some drv->add()
 * failed for some reason. You need to grab sysdev_drivers_lock before
 * calling this.
 */
static void __sysdev_driver_remove(struct sysdev_class *cls,
				   struct sysdev_driver *drv,
				   struct sys_device *from_dev)
{
	struct sys_device *dev = from_dev;

	list_del_init(&drv->entry);
	if (!cls)
		return;

	if (!drv->remove)
		goto kset_put;

	if (dev)
		list_for_each_entry_continue_reverse(dev, &cls->kset.list,
						     kobj.entry)
			drv->remove(dev);
	else
		list_for_each_entry(dev, &cls->kset.list, kobj.entry)
			drv->remove(dev);

kset_put:
	kset_put(&cls->kset);
}

/**
 *	sysdev_driver_register - Register auxiliary driver
 *	@cls:	Device class driver belongs to.
 *	@drv:	Driver.
 *
 *	@drv is inserted into @cls->drivers to be
 *	called on each operation on devices of that class. The refcount
 *	of @cls is incremented.
 */
int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
{
	struct sys_device *dev = NULL;
	int err = 0;

	if (!cls) {
		WARN(1, KERN_WARNING "sysdev: invalid class passed to %s!\n",
			__func__);
		return -EINVAL;
	}

	/* Check whether this driver has already been added to a class. */
	if (drv->entry.next && !list_empty(&drv->entry))
		WARN(1, KERN_WARNING "sysdev: class %s: driver (%p) has already"
			" been registered to a class, something is wrong, but "
			"will forge on!\n", cls->name, drv);

	mutex_lock(&sysdev_drivers_lock);
	if (cls && kset_get(&cls->kset)) {
		list_add_tail(&drv->entry, &cls->drivers);

		/* If devices of this class already exist, tell the driver */
		if (drv->add) {
			list_for_each_entry(dev, &cls->kset.list, kobj.entry) {
				err = drv->add(dev);
				if (err)
					goto unwind;
			}
		}
	} else {
		err = -EINVAL;
		WARN(1, KERN_ERR "%s: invalid device class\n", __func__);
	}

	goto unlock;

unwind:
	__sysdev_driver_remove(cls, drv, dev);

unlock:
	mutex_unlock(&sysdev_drivers_lock);
	return err;
}

/**
 *	sysdev_driver_unregister - Remove an auxiliary driver.
 *	@cls:	Class driver belongs to.
 *	@drv:	Driver.
 */
void sysdev_driver_unregister(struct sysdev_class *cls,
			      struct sysdev_driver *drv)
{
	mutex_lock(&sysdev_drivers_lock);
	__sysdev_driver_remove(cls, drv, NULL);
	mutex_unlock(&sysdev_drivers_lock);
}
EXPORT_SYMBOL_GPL(sysdev_driver_register);
EXPORT_SYMBOL_GPL(sysdev_driver_unregister);

/**
 *	sysdev_register - add a system device to the tree
 *	@sysdev:	device in question
 *
 */
int sysdev_register(struct sys_device *sysdev)
{
	int error;
	struct sysdev_class *cls = sysdev->cls;

	if (!cls)
		return -EINVAL;

	pr_debug("Registering sys device of class '%s'\n",
		 kobject_name(&cls->kset.kobj));

	/* initialize the kobject to 0, in case it had previously been used */
	memset(&sysdev->kobj, 0x00, sizeof(struct kobject));

	/* Make sure the kset is set */
	sysdev->kobj.kset = &cls->kset;

	/* Register the object */
	error = kobject_init_and_add(&sysdev->kobj, &ktype_sysdev, NULL,
				     "%s%d", kobject_name(&cls->kset.kobj),
				     sysdev->id);

	if (!error) {
		struct sysdev_driver *drv;

		pr_debug("Registering sys device '%s'\n",
			 kobject_name(&sysdev->kobj));

		mutex_lock(&sysdev_drivers_lock);
		/* Generic notification is implicit, because it's that
		 * code that should have called us.
		 */

		/* Notify class auxiliary drivers */
		list_for_each_entry(drv, &cls->drivers, entry) {
			if (drv->add)
				drv->add(sysdev);
		}
		mutex_unlock(&sysdev_drivers_lock);
		kobject_uevent(&sysdev->kobj, KOBJ_ADD);
	}

	return error;
}

void sysdev_unregister(struct sys_device *sysdev)
{
	struct sysdev_driver *drv;

	mutex_lock(&sysdev_drivers_lock);
	list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
		if (drv->remove)
			drv->remove(sysdev);
	}
	mutex_unlock(&sysdev_drivers_lock);

	kobject_put(&sysdev->kobj);
}

EXPORT_SYMBOL_GPL(sysdev_register);
EXPORT_SYMBOL_GPL(sysdev_unregister);

int __init system_bus_init(void)
{
	system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
	if (!system_kset)
		return -ENOMEM;
	return 0;
}

#define to_ext_attr(x) container_of(x, struct sysdev_ext_attribute, attr)

ssize_t sysdev_store_ulong(struct sys_device *sysdev,
			   struct sysdev_attribute *attr,
			   const char *buf, size_t size)
{
	struct sysdev_ext_attribute *ea = to_ext_attr(attr);
	char *end;
	unsigned long new = simple_strtoul(buf, &end, 0);
	if (end == buf)
		return -EINVAL;
	*(unsigned long *)(ea->var) = new;
	/* Always return full write size even if we didn't consume all */
	return size;
}
EXPORT_SYMBOL_GPL(sysdev_store_ulong);

ssize_t sysdev_show_ulong(struct sys_device *sysdev,
			  struct sysdev_attribute *attr,
			  char *buf)
{
	struct sysdev_ext_attribute *ea = to_ext_attr(attr);
	return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
}
EXPORT_SYMBOL_GPL(sysdev_show_ulong);

ssize_t sysdev_store_int(struct sys_device *sysdev,
			   struct sysdev_attribute *attr,
			   const char *buf, size_t size)
{
	struct sysdev_ext_attribute *ea = to_ext_attr(attr);
	char *end;
	long new = simple_strtol(buf, &end, 0);
	if (end == buf || new > INT_MAX || new < INT_MIN)
		return -EINVAL;
	*(int *)(ea->var) = new;
	/* Always return full write size even if we didn't consume all */
	return size;
}
EXPORT_SYMBOL_GPL(sysdev_store_int);

ssize_t sysdev_show_int(struct sys_device *sysdev,
			  struct sysdev_attribute *attr,
			  char *buf)
{
	struct sysdev_ext_attribute *ea = to_ext_attr(attr);
	return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
}
EXPORT_SYMBOL_GPL(sysdev_show_int);