xref: /linux/drivers/isdn/mISDN/core.c (revision 7fc7f25419f5a6b09199ba4b5026b94ef184fa79)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2008  by Karsten Keil <kkeil@novell.com>
4  */
5 
6 #include <linux/slab.h>
7 #include <linux/types.h>
8 #include <linux/stddef.h>
9 #include <linux/module.h>
10 #include <linux/spinlock.h>
11 #include <linux/mISDNif.h>
12 #include "core.h"
13 
14 static u_int debug;
15 
16 MODULE_AUTHOR("Karsten Keil");
17 MODULE_LICENSE("GPL");
18 module_param(debug, uint, S_IRUGO | S_IWUSR);
19 
20 static u64		device_ids;
21 #define MAX_DEVICE_ID	63
22 
23 static LIST_HEAD(Bprotocols);
24 static DEFINE_RWLOCK(bp_lock);
25 
26 static void mISDN_dev_release(struct device *dev)
27 {
28 	/* nothing to do: the device is part of its parent's data structure */
29 }
30 
31 static ssize_t id_show(struct device *dev,
32 		       struct device_attribute *attr, char *buf)
33 {
34 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
35 
36 	if (!mdev)
37 		return -ENODEV;
38 	return sprintf(buf, "%d\n", mdev->id);
39 }
40 static DEVICE_ATTR_RO(id);
41 
42 static ssize_t nrbchan_show(struct device *dev,
43 			    struct device_attribute *attr, char *buf)
44 {
45 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
46 
47 	if (!mdev)
48 		return -ENODEV;
49 	return sprintf(buf, "%d\n", mdev->nrbchan);
50 }
51 static DEVICE_ATTR_RO(nrbchan);
52 
53 static ssize_t d_protocols_show(struct device *dev,
54 				struct device_attribute *attr, char *buf)
55 {
56 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
57 
58 	if (!mdev)
59 		return -ENODEV;
60 	return sprintf(buf, "%d\n", mdev->Dprotocols);
61 }
62 static DEVICE_ATTR_RO(d_protocols);
63 
64 static ssize_t b_protocols_show(struct device *dev,
65 				struct device_attribute *attr, char *buf)
66 {
67 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
68 
69 	if (!mdev)
70 		return -ENODEV;
71 	return sprintf(buf, "%d\n", mdev->Bprotocols | get_all_Bprotocols());
72 }
73 static DEVICE_ATTR_RO(b_protocols);
74 
75 static ssize_t protocol_show(struct device *dev,
76 			     struct device_attribute *attr, char *buf)
77 {
78 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
79 
80 	if (!mdev)
81 		return -ENODEV;
82 	return sprintf(buf, "%d\n", mdev->D.protocol);
83 }
84 static DEVICE_ATTR_RO(protocol);
85 
86 static ssize_t name_show(struct device *dev,
87 			 struct device_attribute *attr, char *buf)
88 {
89 	strcpy(buf, dev_name(dev));
90 	return strlen(buf);
91 }
92 static DEVICE_ATTR_RO(name);
93 
94 #if 0 /* hangs */
95 static ssize_t name_set(struct device *dev, struct device_attribute *attr,
96 			const char *buf, size_t count)
97 {
98 	int err = 0;
99 	char *out = kmalloc(count + 1, GFP_KERNEL);
100 
101 	if (!out)
102 		return -ENOMEM;
103 
104 	memcpy(out, buf, count);
105 	if (count && out[count - 1] == '\n')
106 		out[--count] = 0;
107 	if (count)
108 		err = device_rename(dev, out);
109 	kfree(out);
110 
111 	return (err < 0) ? err : count;
112 }
113 static DEVICE_ATTR_RW(name);
114 #endif
115 
116 static ssize_t channelmap_show(struct device *dev,
117 			       struct device_attribute *attr, char *buf)
118 {
119 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
120 	char *bp = buf;
121 	int i;
122 
123 	for (i = 0; i <= mdev->nrbchan; i++)
124 		*bp++ = test_channelmap(i, mdev->channelmap) ? '1' : '0';
125 
126 	return bp - buf;
127 }
128 static DEVICE_ATTR_RO(channelmap);
129 
130 static struct attribute *mISDN_attrs[] = {
131 	&dev_attr_id.attr,
132 	&dev_attr_d_protocols.attr,
133 	&dev_attr_b_protocols.attr,
134 	&dev_attr_protocol.attr,
135 	&dev_attr_channelmap.attr,
136 	&dev_attr_nrbchan.attr,
137 	&dev_attr_name.attr,
138 	NULL,
139 };
140 ATTRIBUTE_GROUPS(mISDN);
141 
142 static int mISDN_uevent(struct device *dev, struct kobj_uevent_env *env)
143 {
144 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
145 
146 	if (!mdev)
147 		return 0;
148 
149 	if (add_uevent_var(env, "nchans=%d", mdev->nrbchan))
150 		return -ENOMEM;
151 
152 	return 0;
153 }
154 
155 static void mISDN_class_release(struct class *cls)
156 {
157 	/* do nothing, it's static */
158 }
159 
160 static struct class mISDN_class = {
161 	.name = "mISDN",
162 	.owner = THIS_MODULE,
163 	.dev_uevent = mISDN_uevent,
164 	.dev_groups = mISDN_groups,
165 	.dev_release = mISDN_dev_release,
166 	.class_release = mISDN_class_release,
167 };
168 
169 static int
170 _get_mdevice(struct device *dev, const void *id)
171 {
172 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
173 
174 	if (!mdev)
175 		return 0;
176 	if (mdev->id != *(const u_int *)id)
177 		return 0;
178 	return 1;
179 }
180 
181 struct mISDNdevice
182 *get_mdevice(u_int id)
183 {
184 	return dev_to_mISDN(class_find_device(&mISDN_class, NULL, &id,
185 					      _get_mdevice));
186 }
187 
188 static int
189 _get_mdevice_count(struct device *dev, void *cnt)
190 {
191 	*(int *)cnt += 1;
192 	return 0;
193 }
194 
195 int
196 get_mdevice_count(void)
197 {
198 	int cnt = 0;
199 
200 	class_for_each_device(&mISDN_class, NULL, &cnt, _get_mdevice_count);
201 	return cnt;
202 }
203 
204 static int
205 get_free_devid(void)
206 {
207 	u_int	i;
208 
209 	for (i = 0; i <= MAX_DEVICE_ID; i++)
210 		if (!test_and_set_bit(i, (u_long *)&device_ids))
211 			break;
212 	if (i > MAX_DEVICE_ID)
213 		return -EBUSY;
214 	return i;
215 }
216 
217 int
218 mISDN_register_device(struct mISDNdevice *dev,
219 		      struct device *parent, char *name)
220 {
221 	int	err;
222 
223 	err = get_free_devid();
224 	if (err < 0)
225 		goto error1;
226 	dev->id = err;
227 
228 	device_initialize(&dev->dev);
229 	if (name && name[0])
230 		dev_set_name(&dev->dev, "%s", name);
231 	else
232 		dev_set_name(&dev->dev, "mISDN%d", dev->id);
233 	if (debug & DEBUG_CORE)
234 		printk(KERN_DEBUG "mISDN_register %s %d\n",
235 		       dev_name(&dev->dev), dev->id);
236 	dev->dev.class = &mISDN_class;
237 
238 	err = create_stack(dev);
239 	if (err)
240 		goto error1;
241 
242 	dev->dev.platform_data = dev;
243 	dev->dev.parent = parent;
244 	dev_set_drvdata(&dev->dev, dev);
245 
246 	err = device_add(&dev->dev);
247 	if (err)
248 		goto error3;
249 	return 0;
250 
251 error3:
252 	delete_stack(dev);
253 error1:
254 	put_device(&dev->dev);
255 	return err;
256 
257 }
258 EXPORT_SYMBOL(mISDN_register_device);
259 
260 void
261 mISDN_unregister_device(struct mISDNdevice *dev) {
262 	if (debug & DEBUG_CORE)
263 		printk(KERN_DEBUG "mISDN_unregister %s %d\n",
264 		       dev_name(&dev->dev), dev->id);
265 	/* sysfs_remove_link(&dev->dev.kobj, "device"); */
266 	device_del(&dev->dev);
267 	dev_set_drvdata(&dev->dev, NULL);
268 
269 	test_and_clear_bit(dev->id, (u_long *)&device_ids);
270 	delete_stack(dev);
271 	put_device(&dev->dev);
272 }
273 EXPORT_SYMBOL(mISDN_unregister_device);
274 
275 u_int
276 get_all_Bprotocols(void)
277 {
278 	struct Bprotocol	*bp;
279 	u_int	m = 0;
280 
281 	read_lock(&bp_lock);
282 	list_for_each_entry(bp, &Bprotocols, list)
283 		m |= bp->Bprotocols;
284 	read_unlock(&bp_lock);
285 	return m;
286 }
287 
288 struct Bprotocol *
289 get_Bprotocol4mask(u_int m)
290 {
291 	struct Bprotocol	*bp;
292 
293 	read_lock(&bp_lock);
294 	list_for_each_entry(bp, &Bprotocols, list)
295 		if (bp->Bprotocols & m) {
296 			read_unlock(&bp_lock);
297 			return bp;
298 		}
299 	read_unlock(&bp_lock);
300 	return NULL;
301 }
302 
303 struct Bprotocol *
304 get_Bprotocol4id(u_int id)
305 {
306 	u_int	m;
307 
308 	if (id < ISDN_P_B_START || id > 63) {
309 		printk(KERN_WARNING "%s id not in range  %d\n",
310 		       __func__, id);
311 		return NULL;
312 	}
313 	m = 1 << (id & ISDN_P_B_MASK);
314 	return get_Bprotocol4mask(m);
315 }
316 
317 int
318 mISDN_register_Bprotocol(struct Bprotocol *bp)
319 {
320 	u_long			flags;
321 	struct Bprotocol	*old;
322 
323 	if (debug & DEBUG_CORE)
324 		printk(KERN_DEBUG "%s: %s/%x\n", __func__,
325 		       bp->name, bp->Bprotocols);
326 	old = get_Bprotocol4mask(bp->Bprotocols);
327 	if (old) {
328 		printk(KERN_WARNING
329 		       "register duplicate protocol old %s/%x new %s/%x\n",
330 		       old->name, old->Bprotocols, bp->name, bp->Bprotocols);
331 		return -EBUSY;
332 	}
333 	write_lock_irqsave(&bp_lock, flags);
334 	list_add_tail(&bp->list, &Bprotocols);
335 	write_unlock_irqrestore(&bp_lock, flags);
336 	return 0;
337 }
338 EXPORT_SYMBOL(mISDN_register_Bprotocol);
339 
340 void
341 mISDN_unregister_Bprotocol(struct Bprotocol *bp)
342 {
343 	u_long	flags;
344 
345 	if (debug & DEBUG_CORE)
346 		printk(KERN_DEBUG "%s: %s/%x\n", __func__, bp->name,
347 		       bp->Bprotocols);
348 	write_lock_irqsave(&bp_lock, flags);
349 	list_del(&bp->list);
350 	write_unlock_irqrestore(&bp_lock, flags);
351 }
352 EXPORT_SYMBOL(mISDN_unregister_Bprotocol);
353 
354 static const char *msg_no_channel = "<no channel>";
355 static const char *msg_no_stack = "<no stack>";
356 static const char *msg_no_stackdev = "<no stack device>";
357 
358 const char *mISDNDevName4ch(struct mISDNchannel *ch)
359 {
360 	if (!ch)
361 		return msg_no_channel;
362 	if (!ch->st)
363 		return msg_no_stack;
364 	if (!ch->st->dev)
365 		return msg_no_stackdev;
366 	return dev_name(&ch->st->dev->dev);
367 };
368 EXPORT_SYMBOL(mISDNDevName4ch);
369 
370 static int
371 mISDNInit(void)
372 {
373 	int	err;
374 
375 	printk(KERN_INFO "Modular ISDN core version %d.%d.%d\n",
376 	       MISDN_MAJOR_VERSION, MISDN_MINOR_VERSION, MISDN_RELEASE);
377 	mISDN_init_clock(&debug);
378 	mISDN_initstack(&debug);
379 	err = class_register(&mISDN_class);
380 	if (err)
381 		goto error1;
382 	err = mISDN_inittimer(&debug);
383 	if (err)
384 		goto error2;
385 	err = Isdnl1_Init(&debug);
386 	if (err)
387 		goto error3;
388 	err = Isdnl2_Init(&debug);
389 	if (err)
390 		goto error4;
391 	err = misdn_sock_init(&debug);
392 	if (err)
393 		goto error5;
394 	return 0;
395 
396 error5:
397 	Isdnl2_cleanup();
398 error4:
399 	Isdnl1_cleanup();
400 error3:
401 	mISDN_timer_cleanup();
402 error2:
403 	class_unregister(&mISDN_class);
404 error1:
405 	return err;
406 }
407 
408 static void mISDN_cleanup(void)
409 {
410 	misdn_sock_cleanup();
411 	Isdnl2_cleanup();
412 	Isdnl1_cleanup();
413 	mISDN_timer_cleanup();
414 	class_unregister(&mISDN_class);
415 
416 	printk(KERN_DEBUG "mISDNcore unloaded\n");
417 }
418 
419 module_init(mISDNInit);
420 module_exit(mISDN_cleanup);
421