1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright(c) 2013 Mauro Carvalho Chehab
4 
5 #include "smscoreapi.h"
6 
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/init.h>
10 #include <linux/debugfs.h>
11 #include <linux/spinlock.h>
12 #include <linux/usb.h>
13 
14 #include <media/dmxdev.h>
15 #include <media/dvbdev.h>
16 #include <media/dvb_demux.h>
17 #include <media/dvb_frontend.h>
18 
19 #include "smsdvb.h"
20 
21 static struct dentry *smsdvb_debugfs_usb_root;
22 
23 struct smsdvb_debugfs {
24 	struct kref		refcount;
25 	spinlock_t		lock;
26 
27 	char			stats_data[PAGE_SIZE];
28 	unsigned		stats_count;
29 	bool			stats_was_read;
30 
31 	wait_queue_head_t	stats_queue;
32 };
33 
34 static void smsdvb_print_dvb_stats(struct smsdvb_debugfs *debug_data,
35 			    struct sms_stats *p)
36 {
37 	int n = 0;
38 	char *buf;
39 
40 	spin_lock(&debug_data->lock);
41 	if (debug_data->stats_count) {
42 		spin_unlock(&debug_data->lock);
43 		return;
44 	}
45 
46 	buf = debug_data->stats_data;
47 
48 	n += snprintf(&buf[n], PAGE_SIZE - n,
49 		      "is_rf_locked = %d\n", p->is_rf_locked);
50 	n += snprintf(&buf[n], PAGE_SIZE - n,
51 		      "is_demod_locked = %d\n", p->is_demod_locked);
52 	n += snprintf(&buf[n], PAGE_SIZE - n,
53 		      "is_external_lna_on = %d\n", p->is_external_lna_on);
54 	n += snprintf(&buf[n], PAGE_SIZE - n,
55 		      "SNR = %d\n", p->SNR);
56 	n += snprintf(&buf[n], PAGE_SIZE - n,
57 		      "ber = %d\n", p->ber);
58 	n += snprintf(&buf[n], PAGE_SIZE - n,
59 		      "FIB_CRC = %d\n", p->FIB_CRC);
60 	n += snprintf(&buf[n], PAGE_SIZE - n,
61 		      "ts_per = %d\n", p->ts_per);
62 	n += snprintf(&buf[n], PAGE_SIZE - n,
63 		      "MFER = %d\n", p->MFER);
64 	n += snprintf(&buf[n], PAGE_SIZE - n,
65 		      "RSSI = %d\n", p->RSSI);
66 	n += snprintf(&buf[n], PAGE_SIZE - n,
67 		      "in_band_pwr = %d\n", p->in_band_pwr);
68 	n += snprintf(&buf[n], PAGE_SIZE - n,
69 		      "carrier_offset = %d\n", p->carrier_offset);
70 	n += snprintf(&buf[n], PAGE_SIZE - n,
71 		      "modem_state = %d\n", p->modem_state);
72 	n += snprintf(&buf[n], PAGE_SIZE - n,
73 		      "frequency = %d\n", p->frequency);
74 	n += snprintf(&buf[n], PAGE_SIZE - n,
75 		      "bandwidth = %d\n", p->bandwidth);
76 	n += snprintf(&buf[n], PAGE_SIZE - n,
77 		      "transmission_mode = %d\n", p->transmission_mode);
78 	n += snprintf(&buf[n], PAGE_SIZE - n,
79 		      "modem_state = %d\n", p->modem_state);
80 	n += snprintf(&buf[n], PAGE_SIZE - n,
81 		      "guard_interval = %d\n", p->guard_interval);
82 	n += snprintf(&buf[n], PAGE_SIZE - n,
83 		      "code_rate = %d\n", p->code_rate);
84 	n += snprintf(&buf[n], PAGE_SIZE - n,
85 		      "lp_code_rate = %d\n", p->lp_code_rate);
86 	n += snprintf(&buf[n], PAGE_SIZE - n,
87 		      "hierarchy = %d\n", p->hierarchy);
88 	n += snprintf(&buf[n], PAGE_SIZE - n,
89 		      "constellation = %d\n", p->constellation);
90 	n += snprintf(&buf[n], PAGE_SIZE - n,
91 		      "burst_size = %d\n", p->burst_size);
92 	n += snprintf(&buf[n], PAGE_SIZE - n,
93 		      "burst_duration = %d\n", p->burst_duration);
94 	n += snprintf(&buf[n], PAGE_SIZE - n,
95 		      "burst_cycle_time = %d\n", p->burst_cycle_time);
96 	n += snprintf(&buf[n], PAGE_SIZE - n,
97 		      "calc_burst_cycle_time = %d\n",
98 		      p->calc_burst_cycle_time);
99 	n += snprintf(&buf[n], PAGE_SIZE - n,
100 		      "num_of_rows = %d\n", p->num_of_rows);
101 	n += snprintf(&buf[n], PAGE_SIZE - n,
102 		      "num_of_padd_cols = %d\n", p->num_of_padd_cols);
103 	n += snprintf(&buf[n], PAGE_SIZE - n,
104 		      "num_of_punct_cols = %d\n", p->num_of_punct_cols);
105 	n += snprintf(&buf[n], PAGE_SIZE - n,
106 		      "error_ts_packets = %d\n", p->error_ts_packets);
107 	n += snprintf(&buf[n], PAGE_SIZE - n,
108 		      "total_ts_packets = %d\n", p->total_ts_packets);
109 	n += snprintf(&buf[n], PAGE_SIZE - n,
110 		      "num_of_valid_mpe_tlbs = %d\n", p->num_of_valid_mpe_tlbs);
111 	n += snprintf(&buf[n], PAGE_SIZE - n,
112 		      "num_of_invalid_mpe_tlbs = %d\n", p->num_of_invalid_mpe_tlbs);
113 	n += snprintf(&buf[n], PAGE_SIZE - n,
114 		      "num_of_corrected_mpe_tlbs = %d\n", p->num_of_corrected_mpe_tlbs);
115 	n += snprintf(&buf[n], PAGE_SIZE - n,
116 		      "ber_error_count = %d\n", p->ber_error_count);
117 	n += snprintf(&buf[n], PAGE_SIZE - n,
118 		      "ber_bit_count = %d\n", p->ber_bit_count);
119 	n += snprintf(&buf[n], PAGE_SIZE - n,
120 		      "sms_to_host_tx_errors = %d\n", p->sms_to_host_tx_errors);
121 	n += snprintf(&buf[n], PAGE_SIZE - n,
122 		      "pre_ber = %d\n", p->pre_ber);
123 	n += snprintf(&buf[n], PAGE_SIZE - n,
124 		      "cell_id = %d\n", p->cell_id);
125 	n += snprintf(&buf[n], PAGE_SIZE - n,
126 		      "dvbh_srv_ind_hp = %d\n", p->dvbh_srv_ind_hp);
127 	n += snprintf(&buf[n], PAGE_SIZE - n,
128 		      "dvbh_srv_ind_lp = %d\n", p->dvbh_srv_ind_lp);
129 	n += snprintf(&buf[n], PAGE_SIZE - n,
130 		      "num_mpe_received = %d\n", p->num_mpe_received);
131 
132 	debug_data->stats_count = n;
133 	spin_unlock(&debug_data->lock);
134 	wake_up(&debug_data->stats_queue);
135 }
136 
137 static void smsdvb_print_isdb_stats(struct smsdvb_debugfs *debug_data,
138 			     struct sms_isdbt_stats *p)
139 {
140 	int i, n = 0;
141 	char *buf;
142 
143 	spin_lock(&debug_data->lock);
144 	if (debug_data->stats_count) {
145 		spin_unlock(&debug_data->lock);
146 		return;
147 	}
148 
149 	buf = debug_data->stats_data;
150 
151 	n += snprintf(&buf[n], PAGE_SIZE - n,
152 		      "statistics_type = %d\t", p->statistics_type);
153 	n += snprintf(&buf[n], PAGE_SIZE - n,
154 		      "full_size = %d\n", p->full_size);
155 
156 	n += snprintf(&buf[n], PAGE_SIZE - n,
157 		      "is_rf_locked = %d\t\t", p->is_rf_locked);
158 	n += snprintf(&buf[n], PAGE_SIZE - n,
159 		      "is_demod_locked = %d\t", p->is_demod_locked);
160 	n += snprintf(&buf[n], PAGE_SIZE - n,
161 		      "is_external_lna_on = %d\n", p->is_external_lna_on);
162 	n += snprintf(&buf[n], PAGE_SIZE - n,
163 		      "SNR = %d dB\t\t", p->SNR);
164 	n += snprintf(&buf[n], PAGE_SIZE - n,
165 		      "RSSI = %d dBm\t\t", p->RSSI);
166 	n += snprintf(&buf[n], PAGE_SIZE - n,
167 		      "in_band_pwr = %d dBm\n", p->in_band_pwr);
168 	n += snprintf(&buf[n], PAGE_SIZE - n,
169 		      "carrier_offset = %d\t", p->carrier_offset);
170 	n += snprintf(&buf[n], PAGE_SIZE - n,
171 		      "bandwidth = %d\t\t", p->bandwidth);
172 	n += snprintf(&buf[n], PAGE_SIZE - n,
173 		      "frequency = %d Hz\n", p->frequency);
174 	n += snprintf(&buf[n], PAGE_SIZE - n,
175 		      "transmission_mode = %d\t", p->transmission_mode);
176 	n += snprintf(&buf[n], PAGE_SIZE - n,
177 		      "modem_state = %d\t\t", p->modem_state);
178 	n += snprintf(&buf[n], PAGE_SIZE - n,
179 		      "guard_interval = %d\n", p->guard_interval);
180 	n += snprintf(&buf[n], PAGE_SIZE - n,
181 		      "system_type = %d\t\t", p->system_type);
182 	n += snprintf(&buf[n], PAGE_SIZE - n,
183 		      "partial_reception = %d\t", p->partial_reception);
184 	n += snprintf(&buf[n], PAGE_SIZE - n,
185 		      "num_of_layers = %d\n", p->num_of_layers);
186 	n += snprintf(&buf[n], PAGE_SIZE - n,
187 		      "sms_to_host_tx_errors = %d\n", p->sms_to_host_tx_errors);
188 
189 	for (i = 0; i < 3; i++) {
190 		if (p->layer_info[i].number_of_segments < 1 ||
191 		    p->layer_info[i].number_of_segments > 13)
192 			continue;
193 
194 		n += snprintf(&buf[n], PAGE_SIZE - n, "\nLayer %d\n", i);
195 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tcode_rate = %d\t",
196 			      p->layer_info[i].code_rate);
197 		n += snprintf(&buf[n], PAGE_SIZE - n, "constellation = %d\n",
198 			      p->layer_info[i].constellation);
199 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tber = %-5d\t",
200 			      p->layer_info[i].ber);
201 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tber_error_count = %-5d\t",
202 			      p->layer_info[i].ber_error_count);
203 		n += snprintf(&buf[n], PAGE_SIZE - n, "ber_bit_count = %-5d\n",
204 			      p->layer_info[i].ber_bit_count);
205 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tpre_ber = %-5d\t",
206 			      p->layer_info[i].pre_ber);
207 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tts_per = %-5d\n",
208 			      p->layer_info[i].ts_per);
209 		n += snprintf(&buf[n], PAGE_SIZE - n, "\terror_ts_packets = %-5d\t",
210 			      p->layer_info[i].error_ts_packets);
211 		n += snprintf(&buf[n], PAGE_SIZE - n, "total_ts_packets = %-5d\t",
212 			      p->layer_info[i].total_ts_packets);
213 		n += snprintf(&buf[n], PAGE_SIZE - n, "ti_ldepth_i = %d\n",
214 			      p->layer_info[i].ti_ldepth_i);
215 		n += snprintf(&buf[n], PAGE_SIZE - n,
216 			      "\tnumber_of_segments = %d\t",
217 			      p->layer_info[i].number_of_segments);
218 		n += snprintf(&buf[n], PAGE_SIZE - n, "tmcc_errors = %d\n",
219 			      p->layer_info[i].tmcc_errors);
220 	}
221 
222 	debug_data->stats_count = n;
223 	spin_unlock(&debug_data->lock);
224 	wake_up(&debug_data->stats_queue);
225 }
226 
227 static void smsdvb_print_isdb_stats_ex(struct smsdvb_debugfs *debug_data,
228 				struct sms_isdbt_stats_ex *p)
229 {
230 	int i, n = 0;
231 	char *buf;
232 
233 	spin_lock(&debug_data->lock);
234 	if (debug_data->stats_count) {
235 		spin_unlock(&debug_data->lock);
236 		return;
237 	}
238 
239 	buf = debug_data->stats_data;
240 
241 	n += snprintf(&buf[n], PAGE_SIZE - n,
242 		      "statistics_type = %d\t", p->statistics_type);
243 	n += snprintf(&buf[n], PAGE_SIZE - n,
244 		      "full_size = %d\n", p->full_size);
245 
246 	n += snprintf(&buf[n], PAGE_SIZE - n,
247 		      "is_rf_locked = %d\t\t", p->is_rf_locked);
248 	n += snprintf(&buf[n], PAGE_SIZE - n,
249 		      "is_demod_locked = %d\t", p->is_demod_locked);
250 	n += snprintf(&buf[n], PAGE_SIZE - n,
251 		      "is_external_lna_on = %d\n", p->is_external_lna_on);
252 	n += snprintf(&buf[n], PAGE_SIZE - n,
253 		      "SNR = %d dB\t\t", p->SNR);
254 	n += snprintf(&buf[n], PAGE_SIZE - n,
255 		      "RSSI = %d dBm\t\t", p->RSSI);
256 	n += snprintf(&buf[n], PAGE_SIZE - n,
257 		      "in_band_pwr = %d dBm\n", p->in_band_pwr);
258 	n += snprintf(&buf[n], PAGE_SIZE - n,
259 		      "carrier_offset = %d\t", p->carrier_offset);
260 	n += snprintf(&buf[n], PAGE_SIZE - n,
261 		      "bandwidth = %d\t\t", p->bandwidth);
262 	n += snprintf(&buf[n], PAGE_SIZE - n,
263 		      "frequency = %d Hz\n", p->frequency);
264 	n += snprintf(&buf[n], PAGE_SIZE - n,
265 		      "transmission_mode = %d\t", p->transmission_mode);
266 	n += snprintf(&buf[n], PAGE_SIZE - n,
267 		      "modem_state = %d\t\t", p->modem_state);
268 	n += snprintf(&buf[n], PAGE_SIZE - n,
269 		      "guard_interval = %d\n", p->guard_interval);
270 	n += snprintf(&buf[n], PAGE_SIZE - n,
271 		      "system_type = %d\t\t", p->system_type);
272 	n += snprintf(&buf[n], PAGE_SIZE - n,
273 		      "partial_reception = %d\t", p->partial_reception);
274 	n += snprintf(&buf[n], PAGE_SIZE - n,
275 		      "num_of_layers = %d\n", p->num_of_layers);
276 	n += snprintf(&buf[n], PAGE_SIZE - n, "segment_number = %d\t",
277 		      p->segment_number);
278 	n += snprintf(&buf[n], PAGE_SIZE - n, "tune_bw = %d\n",
279 		      p->tune_bw);
280 
281 	for (i = 0; i < 3; i++) {
282 		if (p->layer_info[i].number_of_segments < 1 ||
283 		    p->layer_info[i].number_of_segments > 13)
284 			continue;
285 
286 		n += snprintf(&buf[n], PAGE_SIZE - n, "\nLayer %d\n", i);
287 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tcode_rate = %d\t",
288 			      p->layer_info[i].code_rate);
289 		n += snprintf(&buf[n], PAGE_SIZE - n, "constellation = %d\n",
290 			      p->layer_info[i].constellation);
291 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tber = %-5d\t",
292 			      p->layer_info[i].ber);
293 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tber_error_count = %-5d\t",
294 			      p->layer_info[i].ber_error_count);
295 		n += snprintf(&buf[n], PAGE_SIZE - n, "ber_bit_count = %-5d\n",
296 			      p->layer_info[i].ber_bit_count);
297 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tpre_ber = %-5d\t",
298 			      p->layer_info[i].pre_ber);
299 		n += snprintf(&buf[n], PAGE_SIZE - n, "\tts_per = %-5d\n",
300 			      p->layer_info[i].ts_per);
301 		n += snprintf(&buf[n], PAGE_SIZE - n, "\terror_ts_packets = %-5d\t",
302 			      p->layer_info[i].error_ts_packets);
303 		n += snprintf(&buf[n], PAGE_SIZE - n, "total_ts_packets = %-5d\t",
304 			      p->layer_info[i].total_ts_packets);
305 		n += snprintf(&buf[n], PAGE_SIZE - n, "ti_ldepth_i = %d\n",
306 			      p->layer_info[i].ti_ldepth_i);
307 		n += snprintf(&buf[n], PAGE_SIZE - n,
308 			      "\tnumber_of_segments = %d\t",
309 			      p->layer_info[i].number_of_segments);
310 		n += snprintf(&buf[n], PAGE_SIZE - n, "tmcc_errors = %d\n",
311 			      p->layer_info[i].tmcc_errors);
312 	}
313 
314 
315 	debug_data->stats_count = n;
316 	spin_unlock(&debug_data->lock);
317 
318 	wake_up(&debug_data->stats_queue);
319 }
320 
321 static int smsdvb_stats_open(struct inode *inode, struct file *file)
322 {
323 	struct smsdvb_client_t *client = inode->i_private;
324 	struct smsdvb_debugfs *debug_data = client->debug_data;
325 
326 	kref_get(&debug_data->refcount);
327 
328 	spin_lock(&debug_data->lock);
329 	debug_data->stats_count = 0;
330 	debug_data->stats_was_read = false;
331 	spin_unlock(&debug_data->lock);
332 
333 	file->private_data = debug_data;
334 
335 	return 0;
336 }
337 
338 static void smsdvb_debugfs_data_release(struct kref *ref)
339 {
340 	struct smsdvb_debugfs *debug_data;
341 
342 	debug_data = container_of(ref, struct smsdvb_debugfs, refcount);
343 	kfree(debug_data);
344 }
345 
346 static int smsdvb_stats_wait_read(struct smsdvb_debugfs *debug_data)
347 {
348 	int rc = 1;
349 
350 	spin_lock(&debug_data->lock);
351 
352 	if (debug_data->stats_was_read)
353 		goto exit;
354 
355 	rc = debug_data->stats_count;
356 
357 exit:
358 	spin_unlock(&debug_data->lock);
359 	return rc;
360 }
361 
362 static __poll_t smsdvb_stats_poll(struct file *file, poll_table *wait)
363 {
364 	struct smsdvb_debugfs *debug_data = file->private_data;
365 	int rc;
366 
367 	kref_get(&debug_data->refcount);
368 
369 	poll_wait(file, &debug_data->stats_queue, wait);
370 
371 	rc = smsdvb_stats_wait_read(debug_data);
372 	kref_put(&debug_data->refcount, smsdvb_debugfs_data_release);
373 
374 	return rc > 0 ? EPOLLIN | EPOLLRDNORM : 0;
375 }
376 
377 static ssize_t smsdvb_stats_read(struct file *file, char __user *user_buf,
378 				      size_t nbytes, loff_t *ppos)
379 {
380 	int rc = 0, len;
381 	struct smsdvb_debugfs *debug_data = file->private_data;
382 
383 	kref_get(&debug_data->refcount);
384 
385 	if (file->f_flags & O_NONBLOCK) {
386 		rc = smsdvb_stats_wait_read(debug_data);
387 		if (!rc) {
388 			rc = -EWOULDBLOCK;
389 			goto ret;
390 		}
391 	} else {
392 		rc = wait_event_interruptible(debug_data->stats_queue,
393 				      smsdvb_stats_wait_read(debug_data));
394 		if (rc < 0)
395 			goto ret;
396 	}
397 
398 	if (debug_data->stats_was_read) {
399 		rc = 0;	/* EOF */
400 		goto ret;
401 	}
402 
403 	len = debug_data->stats_count - *ppos;
404 	if (len >= 0)
405 		rc = simple_read_from_buffer(user_buf, nbytes, ppos,
406 					     debug_data->stats_data, len);
407 	else
408 		rc = 0;
409 
410 	if (*ppos >= debug_data->stats_count) {
411 		spin_lock(&debug_data->lock);
412 		debug_data->stats_was_read = true;
413 		spin_unlock(&debug_data->lock);
414 	}
415 ret:
416 	kref_put(&debug_data->refcount, smsdvb_debugfs_data_release);
417 	return rc;
418 }
419 
420 static int smsdvb_stats_release(struct inode *inode, struct file *file)
421 {
422 	struct smsdvb_debugfs *debug_data = file->private_data;
423 
424 	spin_lock(&debug_data->lock);
425 	debug_data->stats_was_read = true;	/* return EOF to read() */
426 	spin_unlock(&debug_data->lock);
427 	wake_up_interruptible_sync(&debug_data->stats_queue);
428 
429 	kref_put(&debug_data->refcount, smsdvb_debugfs_data_release);
430 	file->private_data = NULL;
431 
432 	return 0;
433 }
434 
435 static const struct file_operations debugfs_stats_ops = {
436 	.open = smsdvb_stats_open,
437 	.poll = smsdvb_stats_poll,
438 	.read = smsdvb_stats_read,
439 	.release = smsdvb_stats_release,
440 	.llseek = generic_file_llseek,
441 };
442 
443 /*
444  * Functions used by smsdvb, in order to create the interfaces
445  */
446 
447 int smsdvb_debugfs_create(struct smsdvb_client_t *client)
448 {
449 	struct smscore_device_t *coredev = client->coredev;
450 	struct dentry *d;
451 	struct smsdvb_debugfs *debug_data;
452 
453 	if (!smsdvb_debugfs_usb_root || !coredev->is_usb_device)
454 		return -ENODEV;
455 
456 	client->debugfs = debugfs_create_dir(coredev->devpath,
457 					     smsdvb_debugfs_usb_root);
458 	if (IS_ERR_OR_NULL(client->debugfs)) {
459 		pr_info("Unable to create debugfs %s directory.\n",
460 			coredev->devpath);
461 		return -ENODEV;
462 	}
463 
464 	d = debugfs_create_file("stats", S_IRUGO | S_IWUSR, client->debugfs,
465 				client, &debugfs_stats_ops);
466 	if (!d) {
467 		debugfs_remove(client->debugfs);
468 		return -ENOMEM;
469 	}
470 
471 	debug_data = kzalloc(sizeof(*client->debug_data), GFP_KERNEL);
472 	if (!debug_data)
473 		return -ENOMEM;
474 
475 	client->debug_data        = debug_data;
476 	client->prt_dvb_stats     = smsdvb_print_dvb_stats;
477 	client->prt_isdb_stats    = smsdvb_print_isdb_stats;
478 	client->prt_isdb_stats_ex = smsdvb_print_isdb_stats_ex;
479 
480 	init_waitqueue_head(&debug_data->stats_queue);
481 	spin_lock_init(&debug_data->lock);
482 	kref_init(&debug_data->refcount);
483 
484 	return 0;
485 }
486 
487 void smsdvb_debugfs_release(struct smsdvb_client_t *client)
488 {
489 	if (!client->debugfs)
490 		return;
491 
492 	client->prt_dvb_stats     = NULL;
493 	client->prt_isdb_stats    = NULL;
494 	client->prt_isdb_stats_ex = NULL;
495 
496 	debugfs_remove_recursive(client->debugfs);
497 	kref_put(&client->debug_data->refcount, smsdvb_debugfs_data_release);
498 
499 	client->debug_data = NULL;
500 	client->debugfs = NULL;
501 }
502 
503 int smsdvb_debugfs_register(void)
504 {
505 	struct dentry *d;
506 
507 	/*
508 	 * FIXME: This was written to debug Siano USB devices. So, it creates
509 	 * the debugfs node under <debugfs>/usb.
510 	 * A similar logic would be needed for Siano sdio devices, but, in that
511 	 * case, usb_debug_root is not a good choice.
512 	 *
513 	 * Perhaps the right fix here would be to create another sysfs root
514 	 * node for sdio-based boards, but this may need some logic at sdio
515 	 * subsystem.
516 	 */
517 	d = debugfs_create_dir("smsdvb", usb_debug_root);
518 	if (IS_ERR_OR_NULL(d)) {
519 		pr_err("Couldn't create sysfs node for smsdvb\n");
520 		return PTR_ERR(d);
521 	} else {
522 		smsdvb_debugfs_usb_root = d;
523 	}
524 	return 0;
525 }
526 
527 void smsdvb_debugfs_unregister(void)
528 {
529 	debugfs_remove_recursive(smsdvb_debugfs_usb_root);
530 	smsdvb_debugfs_usb_root = NULL;
531 }
532