xref: /linux/drivers/isdn/mISDN/core.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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(const struct device *dev, struct kobj_uevent_env *env)
143 {
144 	const 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 struct class mISDN_class = {
156 	.name = "mISDN",
157 	.dev_uevent = mISDN_uevent,
158 	.dev_groups = mISDN_groups,
159 	.dev_release = mISDN_dev_release,
160 };
161 
162 static int
163 _get_mdevice(struct device *dev, const void *id)
164 {
165 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
166 
167 	if (!mdev)
168 		return 0;
169 	if (mdev->id != *(const u_int *)id)
170 		return 0;
171 	return 1;
172 }
173 
174 struct mISDNdevice
175 *get_mdevice(u_int id)
176 {
177 	return dev_to_mISDN(class_find_device(&mISDN_class, NULL, &id,
178 					      _get_mdevice));
179 }
180 
181 static int
182 _get_mdevice_count(struct device *dev, void *cnt)
183 {
184 	*(int *)cnt += 1;
185 	return 0;
186 }
187 
188 int
189 get_mdevice_count(void)
190 {
191 	int cnt = 0;
192 
193 	class_for_each_device(&mISDN_class, NULL, &cnt, _get_mdevice_count);
194 	return cnt;
195 }
196 
197 static int
198 get_free_devid(void)
199 {
200 	u_int	i;
201 
202 	for (i = 0; i <= MAX_DEVICE_ID; i++)
203 		if (!test_and_set_bit(i, (u_long *)&device_ids))
204 			break;
205 	if (i > MAX_DEVICE_ID)
206 		return -EBUSY;
207 	return i;
208 }
209 
210 int
211 mISDN_register_device(struct mISDNdevice *dev,
212 		      struct device *parent, char *name)
213 {
214 	int	err;
215 
216 	err = get_free_devid();
217 	if (err < 0)
218 		return err;
219 	dev->id = err;
220 
221 	device_initialize(&dev->dev);
222 	if (name && name[0])
223 		dev_set_name(&dev->dev, "%s", name);
224 	else
225 		dev_set_name(&dev->dev, "mISDN%d", dev->id);
226 	if (debug & DEBUG_CORE)
227 		printk(KERN_DEBUG "mISDN_register %s %d\n",
228 		       dev_name(&dev->dev), dev->id);
229 	dev->dev.class = &mISDN_class;
230 
231 	err = create_stack(dev);
232 	if (err)
233 		goto error1;
234 
235 	dev->dev.platform_data = dev;
236 	dev->dev.parent = parent;
237 	dev_set_drvdata(&dev->dev, dev);
238 
239 	err = device_add(&dev->dev);
240 	if (err)
241 		goto error3;
242 	return 0;
243 
244 error3:
245 	delete_stack(dev);
246 error1:
247 	put_device(&dev->dev);
248 	return err;
249 
250 }
251 EXPORT_SYMBOL(mISDN_register_device);
252 
253 void
254 mISDN_unregister_device(struct mISDNdevice *dev) {
255 	if (debug & DEBUG_CORE)
256 		printk(KERN_DEBUG "mISDN_unregister %s %d\n",
257 		       dev_name(&dev->dev), dev->id);
258 	/* sysfs_remove_link(&dev->dev.kobj, "device"); */
259 	device_del(&dev->dev);
260 	dev_set_drvdata(&dev->dev, NULL);
261 
262 	test_and_clear_bit(dev->id, (u_long *)&device_ids);
263 	delete_stack(dev);
264 	put_device(&dev->dev);
265 }
266 EXPORT_SYMBOL(mISDN_unregister_device);
267 
268 u_int
269 get_all_Bprotocols(void)
270 {
271 	struct Bprotocol	*bp;
272 	u_int	m = 0;
273 
274 	read_lock(&bp_lock);
275 	list_for_each_entry(bp, &Bprotocols, list)
276 		m |= bp->Bprotocols;
277 	read_unlock(&bp_lock);
278 	return m;
279 }
280 
281 struct Bprotocol *
282 get_Bprotocol4mask(u_int m)
283 {
284 	struct Bprotocol	*bp;
285 
286 	read_lock(&bp_lock);
287 	list_for_each_entry(bp, &Bprotocols, list)
288 		if (bp->Bprotocols & m) {
289 			read_unlock(&bp_lock);
290 			return bp;
291 		}
292 	read_unlock(&bp_lock);
293 	return NULL;
294 }
295 
296 struct Bprotocol *
297 get_Bprotocol4id(u_int id)
298 {
299 	u_int	m;
300 
301 	if (id < ISDN_P_B_START || id > 63) {
302 		printk(KERN_WARNING "%s id not in range  %d\n",
303 		       __func__, id);
304 		return NULL;
305 	}
306 	m = 1 << (id & ISDN_P_B_MASK);
307 	return get_Bprotocol4mask(m);
308 }
309 
310 int
311 mISDN_register_Bprotocol(struct Bprotocol *bp)
312 {
313 	u_long			flags;
314 	struct Bprotocol	*old;
315 
316 	if (debug & DEBUG_CORE)
317 		printk(KERN_DEBUG "%s: %s/%x\n", __func__,
318 		       bp->name, bp->Bprotocols);
319 	old = get_Bprotocol4mask(bp->Bprotocols);
320 	if (old) {
321 		printk(KERN_WARNING
322 		       "register duplicate protocol old %s/%x new %s/%x\n",
323 		       old->name, old->Bprotocols, bp->name, bp->Bprotocols);
324 		return -EBUSY;
325 	}
326 	write_lock_irqsave(&bp_lock, flags);
327 	list_add_tail(&bp->list, &Bprotocols);
328 	write_unlock_irqrestore(&bp_lock, flags);
329 	return 0;
330 }
331 EXPORT_SYMBOL(mISDN_register_Bprotocol);
332 
333 void
334 mISDN_unregister_Bprotocol(struct Bprotocol *bp)
335 {
336 	u_long	flags;
337 
338 	if (debug & DEBUG_CORE)
339 		printk(KERN_DEBUG "%s: %s/%x\n", __func__, bp->name,
340 		       bp->Bprotocols);
341 	write_lock_irqsave(&bp_lock, flags);
342 	list_del(&bp->list);
343 	write_unlock_irqrestore(&bp_lock, flags);
344 }
345 EXPORT_SYMBOL(mISDN_unregister_Bprotocol);
346 
347 static const char *msg_no_channel = "<no channel>";
348 static const char *msg_no_stack = "<no stack>";
349 static const char *msg_no_stackdev = "<no stack device>";
350 
351 const char *mISDNDevName4ch(struct mISDNchannel *ch)
352 {
353 	if (!ch)
354 		return msg_no_channel;
355 	if (!ch->st)
356 		return msg_no_stack;
357 	if (!ch->st->dev)
358 		return msg_no_stackdev;
359 	return dev_name(&ch->st->dev->dev);
360 };
361 EXPORT_SYMBOL(mISDNDevName4ch);
362 
363 static int
364 mISDNInit(void)
365 {
366 	int	err;
367 
368 	printk(KERN_INFO "Modular ISDN core version %d.%d.%d\n",
369 	       MISDN_MAJOR_VERSION, MISDN_MINOR_VERSION, MISDN_RELEASE);
370 	mISDN_init_clock(&debug);
371 	mISDN_initstack(&debug);
372 	err = class_register(&mISDN_class);
373 	if (err)
374 		goto error1;
375 	err = mISDN_inittimer(&debug);
376 	if (err)
377 		goto error2;
378 	err = Isdnl1_Init(&debug);
379 	if (err)
380 		goto error3;
381 	err = Isdnl2_Init(&debug);
382 	if (err)
383 		goto error4;
384 	err = misdn_sock_init(&debug);
385 	if (err)
386 		goto error5;
387 	return 0;
388 
389 error5:
390 	Isdnl2_cleanup();
391 error4:
392 	Isdnl1_cleanup();
393 error3:
394 	mISDN_timer_cleanup();
395 error2:
396 	class_unregister(&mISDN_class);
397 error1:
398 	return err;
399 }
400 
401 static void mISDN_cleanup(void)
402 {
403 	misdn_sock_cleanup();
404 	Isdnl2_cleanup();
405 	Isdnl1_cleanup();
406 	mISDN_timer_cleanup();
407 	class_unregister(&mISDN_class);
408 
409 	printk(KERN_DEBUG "mISDNcore unloaded\n");
410 }
411 
412 module_init(mISDNInit);
413 module_exit(mISDN_cleanup);
414