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 += scnprintf(&buf[n], PAGE_SIZE - n,
49 		      "is_rf_locked = %d\n", p->is_rf_locked);
50 	n += scnprintf(&buf[n], PAGE_SIZE - n,
51 		      "is_demod_locked = %d\n", p->is_demod_locked);
52 	n += scnprintf(&buf[n], PAGE_SIZE - n,
53 		      "is_external_lna_on = %d\n", p->is_external_lna_on);
54 	n += scnprintf(&buf[n], PAGE_SIZE - n,
55 		      "SNR = %d\n", p->SNR);
56 	n += scnprintf(&buf[n], PAGE_SIZE - n,
57 		      "ber = %d\n", p->ber);
58 	n += scnprintf(&buf[n], PAGE_SIZE - n,
59 		      "FIB_CRC = %d\n", p->FIB_CRC);
60 	n += scnprintf(&buf[n], PAGE_SIZE - n,
61 		      "ts_per = %d\n", p->ts_per);
62 	n += scnprintf(&buf[n], PAGE_SIZE - n,
63 		      "MFER = %d\n", p->MFER);
64 	n += scnprintf(&buf[n], PAGE_SIZE - n,
65 		      "RSSI = %d\n", p->RSSI);
66 	n += scnprintf(&buf[n], PAGE_SIZE - n,
67 		      "in_band_pwr = %d\n", p->in_band_pwr);
68 	n += scnprintf(&buf[n], PAGE_SIZE - n,
69 		      "carrier_offset = %d\n", p->carrier_offset);
70 	n += scnprintf(&buf[n], PAGE_SIZE - n,
71 		      "modem_state = %d\n", p->modem_state);
72 	n += scnprintf(&buf[n], PAGE_SIZE - n,
73 		      "frequency = %d\n", p->frequency);
74 	n += scnprintf(&buf[n], PAGE_SIZE - n,
75 		      "bandwidth = %d\n", p->bandwidth);
76 	n += scnprintf(&buf[n], PAGE_SIZE - n,
77 		      "transmission_mode = %d\n", p->transmission_mode);
78 	n += scnprintf(&buf[n], PAGE_SIZE - n,
79 		      "modem_state = %d\n", p->modem_state);
80 	n += scnprintf(&buf[n], PAGE_SIZE - n,
81 		      "guard_interval = %d\n", p->guard_interval);
82 	n += scnprintf(&buf[n], PAGE_SIZE - n,
83 		      "code_rate = %d\n", p->code_rate);
84 	n += scnprintf(&buf[n], PAGE_SIZE - n,
85 		      "lp_code_rate = %d\n", p->lp_code_rate);
86 	n += scnprintf(&buf[n], PAGE_SIZE - n,
87 		      "hierarchy = %d\n", p->hierarchy);
88 	n += scnprintf(&buf[n], PAGE_SIZE - n,
89 		      "constellation = %d\n", p->constellation);
90 	n += scnprintf(&buf[n], PAGE_SIZE - n,
91 		      "burst_size = %d\n", p->burst_size);
92 	n += scnprintf(&buf[n], PAGE_SIZE - n,
93 		      "burst_duration = %d\n", p->burst_duration);
94 	n += scnprintf(&buf[n], PAGE_SIZE - n,
95 		      "burst_cycle_time = %d\n", p->burst_cycle_time);
96 	n += scnprintf(&buf[n], PAGE_SIZE - n,
97 		      "calc_burst_cycle_time = %d\n",
98 		      p->calc_burst_cycle_time);
99 	n += scnprintf(&buf[n], PAGE_SIZE - n,
100 		      "num_of_rows = %d\n", p->num_of_rows);
101 	n += scnprintf(&buf[n], PAGE_SIZE - n,
102 		      "num_of_padd_cols = %d\n", p->num_of_padd_cols);
103 	n += scnprintf(&buf[n], PAGE_SIZE - n,
104 		      "num_of_punct_cols = %d\n", p->num_of_punct_cols);
105 	n += scnprintf(&buf[n], PAGE_SIZE - n,
106 		      "error_ts_packets = %d\n", p->error_ts_packets);
107 	n += scnprintf(&buf[n], PAGE_SIZE - n,
108 		      "total_ts_packets = %d\n", p->total_ts_packets);
109 	n += scnprintf(&buf[n], PAGE_SIZE - n,
110 		      "num_of_valid_mpe_tlbs = %d\n", p->num_of_valid_mpe_tlbs);
111 	n += scnprintf(&buf[n], PAGE_SIZE - n,
112 		      "num_of_invalid_mpe_tlbs = %d\n", p->num_of_invalid_mpe_tlbs);
113 	n += scnprintf(&buf[n], PAGE_SIZE - n,
114 		      "num_of_corrected_mpe_tlbs = %d\n", p->num_of_corrected_mpe_tlbs);
115 	n += scnprintf(&buf[n], PAGE_SIZE - n,
116 		      "ber_error_count = %d\n", p->ber_error_count);
117 	n += scnprintf(&buf[n], PAGE_SIZE - n,
118 		      "ber_bit_count = %d\n", p->ber_bit_count);
119 	n += scnprintf(&buf[n], PAGE_SIZE - n,
120 		      "sms_to_host_tx_errors = %d\n", p->sms_to_host_tx_errors);
121 	n += scnprintf(&buf[n], PAGE_SIZE - n,
122 		      "pre_ber = %d\n", p->pre_ber);
123 	n += scnprintf(&buf[n], PAGE_SIZE - n,
124 		      "cell_id = %d\n", p->cell_id);
125 	n += scnprintf(&buf[n], PAGE_SIZE - n,
126 		      "dvbh_srv_ind_hp = %d\n", p->dvbh_srv_ind_hp);
127 	n += scnprintf(&buf[n], PAGE_SIZE - n,
128 		      "dvbh_srv_ind_lp = %d\n", p->dvbh_srv_ind_lp);
129 	n += scnprintf(&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 += scnprintf(&buf[n], PAGE_SIZE - n,
152 		      "statistics_type = %d\t", p->statistics_type);
153 	n += scnprintf(&buf[n], PAGE_SIZE - n,
154 		      "full_size = %d\n", p->full_size);
155 
156 	n += scnprintf(&buf[n], PAGE_SIZE - n,
157 		      "is_rf_locked = %d\t\t", p->is_rf_locked);
158 	n += scnprintf(&buf[n], PAGE_SIZE - n,
159 		      "is_demod_locked = %d\t", p->is_demod_locked);
160 	n += scnprintf(&buf[n], PAGE_SIZE - n,
161 		      "is_external_lna_on = %d\n", p->is_external_lna_on);
162 	n += scnprintf(&buf[n], PAGE_SIZE - n,
163 		      "SNR = %d dB\t\t", p->SNR);
164 	n += scnprintf(&buf[n], PAGE_SIZE - n,
165 		      "RSSI = %d dBm\t\t", p->RSSI);
166 	n += scnprintf(&buf[n], PAGE_SIZE - n,
167 		      "in_band_pwr = %d dBm\n", p->in_band_pwr);
168 	n += scnprintf(&buf[n], PAGE_SIZE - n,
169 		      "carrier_offset = %d\t", p->carrier_offset);
170 	n += scnprintf(&buf[n], PAGE_SIZE - n,
171 		      "bandwidth = %d\t\t", p->bandwidth);
172 	n += scnprintf(&buf[n], PAGE_SIZE - n,
173 		      "frequency = %d Hz\n", p->frequency);
174 	n += scnprintf(&buf[n], PAGE_SIZE - n,
175 		      "transmission_mode = %d\t", p->transmission_mode);
176 	n += scnprintf(&buf[n], PAGE_SIZE - n,
177 		      "modem_state = %d\t\t", p->modem_state);
178 	n += scnprintf(&buf[n], PAGE_SIZE - n,
179 		      "guard_interval = %d\n", p->guard_interval);
180 	n += scnprintf(&buf[n], PAGE_SIZE - n,
181 		      "system_type = %d\t\t", p->system_type);
182 	n += scnprintf(&buf[n], PAGE_SIZE - n,
183 		      "partial_reception = %d\t", p->partial_reception);
184 	n += scnprintf(&buf[n], PAGE_SIZE - n,
185 		      "num_of_layers = %d\n", p->num_of_layers);
186 	n += scnprintf(&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 += scnprintf(&buf[n], PAGE_SIZE - n, "\nLayer %d\n", i);
195 		n += scnprintf(&buf[n], PAGE_SIZE - n, "\tcode_rate = %d\t",
196 			      p->layer_info[i].code_rate);
197 		n += scnprintf(&buf[n], PAGE_SIZE - n, "constellation = %d\n",
198 			      p->layer_info[i].constellation);
199 		n += scnprintf(&buf[n], PAGE_SIZE - n, "\tber = %-5d\t",
200 			      p->layer_info[i].ber);
201 		n += scnprintf(&buf[n], PAGE_SIZE - n,
202 			      "\tber_error_count = %-5d\t",
203 			      p->layer_info[i].ber_error_count);
204 		n += scnprintf(&buf[n], PAGE_SIZE - n, "ber_bit_count = %-5d\n",
205 			      p->layer_info[i].ber_bit_count);
206 		n += scnprintf(&buf[n], PAGE_SIZE - n, "\tpre_ber = %-5d\t",
207 			      p->layer_info[i].pre_ber);
208 		n += scnprintf(&buf[n], PAGE_SIZE - n, "\tts_per = %-5d\n",
209 			      p->layer_info[i].ts_per);
210 		n += scnprintf(&buf[n], PAGE_SIZE - n,
211 			      "\terror_ts_packets = %-5d\t",
212 			      p->layer_info[i].error_ts_packets);
213 		n += scnprintf(&buf[n], PAGE_SIZE - n,
214 			      "total_ts_packets = %-5d\t",
215 			      p->layer_info[i].total_ts_packets);
216 		n += scnprintf(&buf[n], PAGE_SIZE - n, "ti_ldepth_i = %d\n",
217 			      p->layer_info[i].ti_ldepth_i);
218 		n += scnprintf(&buf[n], PAGE_SIZE - n,
219 			      "\tnumber_of_segments = %d\t",
220 			      p->layer_info[i].number_of_segments);
221 		n += scnprintf(&buf[n], PAGE_SIZE - n, "tmcc_errors = %d\n",
222 			      p->layer_info[i].tmcc_errors);
223 	}
224 
225 	debug_data->stats_count = n;
226 	spin_unlock(&debug_data->lock);
227 	wake_up(&debug_data->stats_queue);
228 }
229 
230 static void smsdvb_print_isdb_stats_ex(struct smsdvb_debugfs *debug_data,
231 				struct sms_isdbt_stats_ex *p)
232 {
233 	int i, n = 0;
234 	char *buf;
235 
236 	spin_lock(&debug_data->lock);
237 	if (debug_data->stats_count) {
238 		spin_unlock(&debug_data->lock);
239 		return;
240 	}
241 
242 	buf = debug_data->stats_data;
243 
244 	n += scnprintf(&buf[n], PAGE_SIZE - n,
245 		      "statistics_type = %d\t", p->statistics_type);
246 	n += scnprintf(&buf[n], PAGE_SIZE - n,
247 		      "full_size = %d\n", p->full_size);
248 
249 	n += scnprintf(&buf[n], PAGE_SIZE - n,
250 		      "is_rf_locked = %d\t\t", p->is_rf_locked);
251 	n += scnprintf(&buf[n], PAGE_SIZE - n,
252 		      "is_demod_locked = %d\t", p->is_demod_locked);
253 	n += scnprintf(&buf[n], PAGE_SIZE - n,
254 		      "is_external_lna_on = %d\n", p->is_external_lna_on);
255 	n += scnprintf(&buf[n], PAGE_SIZE - n,
256 		      "SNR = %d dB\t\t", p->SNR);
257 	n += scnprintf(&buf[n], PAGE_SIZE - n,
258 		      "RSSI = %d dBm\t\t", p->RSSI);
259 	n += scnprintf(&buf[n], PAGE_SIZE - n,
260 		      "in_band_pwr = %d dBm\n", p->in_band_pwr);
261 	n += scnprintf(&buf[n], PAGE_SIZE - n,
262 		      "carrier_offset = %d\t", p->carrier_offset);
263 	n += scnprintf(&buf[n], PAGE_SIZE - n,
264 		      "bandwidth = %d\t\t", p->bandwidth);
265 	n += scnprintf(&buf[n], PAGE_SIZE - n,
266 		      "frequency = %d Hz\n", p->frequency);
267 	n += scnprintf(&buf[n], PAGE_SIZE - n,
268 		      "transmission_mode = %d\t", p->transmission_mode);
269 	n += scnprintf(&buf[n], PAGE_SIZE - n,
270 		      "modem_state = %d\t\t", p->modem_state);
271 	n += scnprintf(&buf[n], PAGE_SIZE - n,
272 		      "guard_interval = %d\n", p->guard_interval);
273 	n += scnprintf(&buf[n], PAGE_SIZE - n,
274 		      "system_type = %d\t\t", p->system_type);
275 	n += scnprintf(&buf[n], PAGE_SIZE - n,
276 		      "partial_reception = %d\t", p->partial_reception);
277 	n += scnprintf(&buf[n], PAGE_SIZE - n,
278 		      "num_of_layers = %d\n", p->num_of_layers);
279 	n += scnprintf(&buf[n], PAGE_SIZE - n, "segment_number = %d\t",
280 		      p->segment_number);
281 	n += scnprintf(&buf[n], PAGE_SIZE - n, "tune_bw = %d\n",
282 		      p->tune_bw);
283 
284 	for (i = 0; i < 3; i++) {
285 		if (p->layer_info[i].number_of_segments < 1 ||
286 		    p->layer_info[i].number_of_segments > 13)
287 			continue;
288 
289 		n += scnprintf(&buf[n], PAGE_SIZE - n, "\nLayer %d\n", i);
290 		n += scnprintf(&buf[n], PAGE_SIZE - n, "\tcode_rate = %d\t",
291 			      p->layer_info[i].code_rate);
292 		n += scnprintf(&buf[n], PAGE_SIZE - n, "constellation = %d\n",
293 			      p->layer_info[i].constellation);
294 		n += scnprintf(&buf[n], PAGE_SIZE - n, "\tber = %-5d\t",
295 			      p->layer_info[i].ber);
296 		n += scnprintf(&buf[n], PAGE_SIZE - n,
297 			      "\tber_error_count = %-5d\t",
298 			      p->layer_info[i].ber_error_count);
299 		n += scnprintf(&buf[n], PAGE_SIZE - n, "ber_bit_count = %-5d\n",
300 			      p->layer_info[i].ber_bit_count);
301 		n += scnprintf(&buf[n], PAGE_SIZE - n, "\tpre_ber = %-5d\t",
302 			      p->layer_info[i].pre_ber);
303 		n += scnprintf(&buf[n], PAGE_SIZE - n, "\tts_per = %-5d\n",
304 			      p->layer_info[i].ts_per);
305 		n += scnprintf(&buf[n], PAGE_SIZE - n,
306 			      "\terror_ts_packets = %-5d\t",
307 			      p->layer_info[i].error_ts_packets);
308 		n += scnprintf(&buf[n], PAGE_SIZE - n,
309 			      "total_ts_packets = %-5d\t",
310 			      p->layer_info[i].total_ts_packets);
311 		n += scnprintf(&buf[n], PAGE_SIZE - n, "ti_ldepth_i = %d\n",
312 			      p->layer_info[i].ti_ldepth_i);
313 		n += scnprintf(&buf[n], PAGE_SIZE - n,
314 			      "\tnumber_of_segments = %d\t",
315 			      p->layer_info[i].number_of_segments);
316 		n += scnprintf(&buf[n], PAGE_SIZE - n, "tmcc_errors = %d\n",
317 			      p->layer_info[i].tmcc_errors);
318 	}
319 
320 
321 	debug_data->stats_count = n;
322 	spin_unlock(&debug_data->lock);
323 
324 	wake_up(&debug_data->stats_queue);
325 }
326 
327 static int smsdvb_stats_open(struct inode *inode, struct file *file)
328 {
329 	struct smsdvb_client_t *client = inode->i_private;
330 	struct smsdvb_debugfs *debug_data = client->debug_data;
331 
332 	kref_get(&debug_data->refcount);
333 
334 	spin_lock(&debug_data->lock);
335 	debug_data->stats_count = 0;
336 	debug_data->stats_was_read = false;
337 	spin_unlock(&debug_data->lock);
338 
339 	file->private_data = debug_data;
340 
341 	return 0;
342 }
343 
344 static void smsdvb_debugfs_data_release(struct kref *ref)
345 {
346 	struct smsdvb_debugfs *debug_data;
347 
348 	debug_data = container_of(ref, struct smsdvb_debugfs, refcount);
349 	kfree(debug_data);
350 }
351 
352 static int smsdvb_stats_wait_read(struct smsdvb_debugfs *debug_data)
353 {
354 	int rc = 1;
355 
356 	spin_lock(&debug_data->lock);
357 
358 	if (debug_data->stats_was_read)
359 		goto exit;
360 
361 	rc = debug_data->stats_count;
362 
363 exit:
364 	spin_unlock(&debug_data->lock);
365 	return rc;
366 }
367 
368 static __poll_t smsdvb_stats_poll(struct file *file, poll_table *wait)
369 {
370 	struct smsdvb_debugfs *debug_data = file->private_data;
371 	int rc;
372 
373 	kref_get(&debug_data->refcount);
374 
375 	poll_wait(file, &debug_data->stats_queue, wait);
376 
377 	rc = smsdvb_stats_wait_read(debug_data);
378 	kref_put(&debug_data->refcount, smsdvb_debugfs_data_release);
379 
380 	return rc > 0 ? EPOLLIN | EPOLLRDNORM : 0;
381 }
382 
383 static ssize_t smsdvb_stats_read(struct file *file, char __user *user_buf,
384 				      size_t nbytes, loff_t *ppos)
385 {
386 	int rc = 0, len;
387 	struct smsdvb_debugfs *debug_data = file->private_data;
388 
389 	kref_get(&debug_data->refcount);
390 
391 	if (file->f_flags & O_NONBLOCK) {
392 		rc = smsdvb_stats_wait_read(debug_data);
393 		if (!rc) {
394 			rc = -EWOULDBLOCK;
395 			goto ret;
396 		}
397 	} else {
398 		rc = wait_event_interruptible(debug_data->stats_queue,
399 				      smsdvb_stats_wait_read(debug_data));
400 		if (rc < 0)
401 			goto ret;
402 	}
403 
404 	if (debug_data->stats_was_read) {
405 		rc = 0;	/* EOF */
406 		goto ret;
407 	}
408 
409 	len = debug_data->stats_count - *ppos;
410 	if (len >= 0)
411 		rc = simple_read_from_buffer(user_buf, nbytes, ppos,
412 					     debug_data->stats_data, len);
413 	else
414 		rc = 0;
415 
416 	if (*ppos >= debug_data->stats_count) {
417 		spin_lock(&debug_data->lock);
418 		debug_data->stats_was_read = true;
419 		spin_unlock(&debug_data->lock);
420 	}
421 ret:
422 	kref_put(&debug_data->refcount, smsdvb_debugfs_data_release);
423 	return rc;
424 }
425 
426 static int smsdvb_stats_release(struct inode *inode, struct file *file)
427 {
428 	struct smsdvb_debugfs *debug_data = file->private_data;
429 
430 	spin_lock(&debug_data->lock);
431 	debug_data->stats_was_read = true;	/* return EOF to read() */
432 	spin_unlock(&debug_data->lock);
433 	wake_up_interruptible_sync(&debug_data->stats_queue);
434 
435 	kref_put(&debug_data->refcount, smsdvb_debugfs_data_release);
436 	file->private_data = NULL;
437 
438 	return 0;
439 }
440 
441 static const struct file_operations debugfs_stats_ops = {
442 	.open = smsdvb_stats_open,
443 	.poll = smsdvb_stats_poll,
444 	.read = smsdvb_stats_read,
445 	.release = smsdvb_stats_release,
446 	.llseek = generic_file_llseek,
447 };
448 
449 /*
450  * Functions used by smsdvb, in order to create the interfaces
451  */
452 
453 int smsdvb_debugfs_create(struct smsdvb_client_t *client)
454 {
455 	struct smscore_device_t *coredev = client->coredev;
456 	struct dentry *d;
457 	struct smsdvb_debugfs *debug_data;
458 
459 	if (!smsdvb_debugfs_usb_root || !coredev->is_usb_device)
460 		return -ENODEV;
461 
462 	client->debugfs = debugfs_create_dir(coredev->devpath,
463 					     smsdvb_debugfs_usb_root);
464 	if (IS_ERR_OR_NULL(client->debugfs)) {
465 		pr_info("Unable to create debugfs %s directory.\n",
466 			coredev->devpath);
467 		return -ENODEV;
468 	}
469 
470 	d = debugfs_create_file("stats", S_IRUGO | S_IWUSR, client->debugfs,
471 				client, &debugfs_stats_ops);
472 	if (!d) {
473 		debugfs_remove(client->debugfs);
474 		return -ENOMEM;
475 	}
476 
477 	debug_data = kzalloc(sizeof(*client->debug_data), GFP_KERNEL);
478 	if (!debug_data)
479 		return -ENOMEM;
480 
481 	client->debug_data        = debug_data;
482 	client->prt_dvb_stats     = smsdvb_print_dvb_stats;
483 	client->prt_isdb_stats    = smsdvb_print_isdb_stats;
484 	client->prt_isdb_stats_ex = smsdvb_print_isdb_stats_ex;
485 
486 	init_waitqueue_head(&debug_data->stats_queue);
487 	spin_lock_init(&debug_data->lock);
488 	kref_init(&debug_data->refcount);
489 
490 	return 0;
491 }
492 
493 void smsdvb_debugfs_release(struct smsdvb_client_t *client)
494 {
495 	if (!client->debugfs)
496 		return;
497 
498 	client->prt_dvb_stats     = NULL;
499 	client->prt_isdb_stats    = NULL;
500 	client->prt_isdb_stats_ex = NULL;
501 
502 	debugfs_remove_recursive(client->debugfs);
503 	kref_put(&client->debug_data->refcount, smsdvb_debugfs_data_release);
504 
505 	client->debug_data = NULL;
506 	client->debugfs = NULL;
507 }
508 
509 void smsdvb_debugfs_register(void)
510 {
511 	struct dentry *d;
512 
513 	/*
514 	 * FIXME: This was written to debug Siano USB devices. So, it creates
515 	 * the debugfs node under <debugfs>/usb.
516 	 * A similar logic would be needed for Siano sdio devices, but, in that
517 	 * case, usb_debug_root is not a good choice.
518 	 *
519 	 * Perhaps the right fix here would be to create another sysfs root
520 	 * node for sdio-based boards, but this may need some logic at sdio
521 	 * subsystem.
522 	 */
523 	d = debugfs_create_dir("smsdvb", usb_debug_root);
524 	if (IS_ERR_OR_NULL(d)) {
525 		pr_err("Couldn't create sysfs node for smsdvb\n");
526 		return;
527 	}
528 	smsdvb_debugfs_usb_root = d;
529 }
530 
531 void smsdvb_debugfs_unregister(void)
532 {
533 	if (!smsdvb_debugfs_usb_root)
534 		return;
535 	debugfs_remove_recursive(smsdvb_debugfs_usb_root);
536 	smsdvb_debugfs_usb_root = NULL;
537 }
538