xref: /linux/sound/usb/usx2y/us144mkii.c (revision 55a42f78ffd386e01a5404419f8c5ded7db70a21)
1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
3 /*
4  * ALSA Driver for TASCAM US-144MKII Audio Interface
5  */
6 
7 #include "us144mkii.h"
8 
9 MODULE_AUTHOR("Šerif Rami <ramiserifpersia@gmail.com>");
10 MODULE_DESCRIPTION("ALSA Driver for TASCAM US-144MKII");
11 MODULE_LICENSE("GPL");
12 
13 /**
14  * @brief Module parameters for ALSA card instantiation.
15  *
16  * These parameters allow users to configure how the ALSA sound card
17  * for the TASCAM US-144MKII is instantiated.
18  *
19  * @param index: Array of integers specifying the ALSA card index for each
20  * device. Defaults to -1 (automatic).
21  * @param id: Array of strings specifying the ALSA card ID for each device.
22  *            Defaults to "US144MKII".
23  * @param enable: Array of booleans to enable or disable each device.
24  *                Defaults to {1, 0, ..., 0} (first device enabled).
25  * @param dev_idx: Internal counter for the number of TASCAM devices probed.
26  */
27 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
28 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
29 static bool enable[SNDRV_CARDS] = { 1, [1 ...(SNDRV_CARDS - 1)] = 0 };
30 static int dev_idx;
31 
32 static int tascam_probe(struct usb_interface *intf,
33 			const struct usb_device_id *usb_id);
34 static void tascam_disconnect(struct usb_interface *intf);
35 static int tascam_suspend(struct usb_interface *intf, pm_message_t message);
36 static int tascam_resume(struct usb_interface *intf);
37 
38 void tascam_free_urbs(struct tascam_card *tascam)
39 {
40 	int i;
41 
42 	usb_kill_anchored_urbs(&tascam->playback_anchor);
43 	for (i = 0; i < NUM_PLAYBACK_URBS; i++) {
44 		if (tascam->playback_urbs[i]) {
45 			usb_free_coherent(
46 				tascam->dev, tascam->playback_urb_alloc_size,
47 				tascam->playback_urbs[i]->transfer_buffer,
48 				tascam->playback_urbs[i]->transfer_dma);
49 			usb_free_urb(tascam->playback_urbs[i]);
50 			tascam->playback_urbs[i] = NULL;
51 		}
52 	}
53 
54 	usb_kill_anchored_urbs(&tascam->feedback_anchor);
55 	for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
56 		if (tascam->feedback_urbs[i]) {
57 			usb_free_coherent(
58 				tascam->dev, tascam->feedback_urb_alloc_size,
59 				tascam->feedback_urbs[i]->transfer_buffer,
60 				tascam->feedback_urbs[i]->transfer_dma);
61 			usb_free_urb(tascam->feedback_urbs[i]);
62 			tascam->feedback_urbs[i] = NULL;
63 		}
64 	}
65 
66 	usb_kill_anchored_urbs(&tascam->capture_anchor);
67 	for (i = 0; i < NUM_CAPTURE_URBS; i++) {
68 		if (tascam->capture_urbs[i]) {
69 			usb_free_coherent(
70 				tascam->dev, tascam->capture_urb_alloc_size,
71 				tascam->capture_urbs[i]->transfer_buffer,
72 				tascam->capture_urbs[i]->transfer_dma);
73 			usb_free_urb(tascam->capture_urbs[i]);
74 			tascam->capture_urbs[i] = NULL;
75 		}
76 	}
77 
78 	usb_kill_anchored_urbs(&tascam->midi_in_anchor);
79 	for (i = 0; i < NUM_MIDI_IN_URBS; i++) {
80 		if (tascam->midi_in_urbs[i]) {
81 			usb_free_coherent(
82 				tascam->dev, MIDI_IN_BUF_SIZE,
83 				tascam->midi_in_urbs[i]->transfer_buffer,
84 				tascam->midi_in_urbs[i]->transfer_dma);
85 			usb_free_urb(tascam->midi_in_urbs[i]);
86 			tascam->midi_in_urbs[i] = NULL;
87 		}
88 	}
89 
90 	usb_kill_anchored_urbs(&tascam->midi_out_anchor);
91 	for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
92 		if (tascam->midi_out_urbs[i]) {
93 			usb_free_coherent(
94 				tascam->dev, MIDI_OUT_BUF_SIZE,
95 				tascam->midi_out_urbs[i]->transfer_buffer,
96 				tascam->midi_out_urbs[i]->transfer_dma);
97 			usb_free_urb(tascam->midi_out_urbs[i]);
98 			tascam->midi_out_urbs[i] = NULL;
99 		}
100 	}
101 
102 	kfree(tascam->capture_routing_buffer);
103 	tascam->capture_routing_buffer = NULL;
104 	kfree(tascam->capture_decode_dst_block);
105 	tascam->capture_decode_dst_block = NULL;
106 	kfree(tascam->capture_decode_raw_block);
107 	tascam->capture_decode_raw_block = NULL;
108 	kfree(tascam->capture_ring_buffer);
109 	tascam->capture_ring_buffer = NULL;
110 }
111 
112 int tascam_alloc_urbs(struct tascam_card *tascam)
113 {
114 	int i;
115 	size_t max_packet_size;
116 
117 	max_packet_size = ((96000 / 8000) + 2) * BYTES_PER_FRAME;
118 	tascam->playback_urb_alloc_size =
119 		max_packet_size * PLAYBACK_URB_PACKETS;
120 
121 	for (i = 0; i < NUM_PLAYBACK_URBS; i++) {
122 		struct urb *urb =
123 			usb_alloc_urb(PLAYBACK_URB_PACKETS, GFP_KERNEL);
124 
125 		if (!urb)
126 			goto error;
127 		tascam->playback_urbs[i] = urb;
128 
129 		urb->transfer_buffer = usb_alloc_coherent(
130 			tascam->dev, tascam->playback_urb_alloc_size,
131 			GFP_KERNEL, &urb->transfer_dma);
132 		if (!urb->transfer_buffer)
133 			goto error;
134 
135 		urb->dev = tascam->dev;
136 		urb->pipe = usb_sndisocpipe(tascam->dev, EP_AUDIO_OUT);
137 		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
138 		urb->interval = 1;
139 		urb->context = tascam;
140 		urb->complete = playback_urb_complete;
141 	}
142 
143 	tascam->feedback_urb_alloc_size =
144 		FEEDBACK_PACKET_SIZE * FEEDBACK_URB_PACKETS;
145 
146 	for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
147 		struct urb *f_urb =
148 			usb_alloc_urb(FEEDBACK_URB_PACKETS, GFP_KERNEL);
149 
150 		if (!f_urb)
151 			goto error;
152 		tascam->feedback_urbs[i] = f_urb;
153 
154 		f_urb->transfer_buffer = usb_alloc_coherent(
155 			tascam->dev, tascam->feedback_urb_alloc_size,
156 			GFP_KERNEL, &f_urb->transfer_dma);
157 		if (!f_urb->transfer_buffer)
158 			goto error;
159 
160 		f_urb->dev = tascam->dev;
161 		f_urb->pipe =
162 			usb_rcvisocpipe(tascam->dev, EP_PLAYBACK_FEEDBACK);
163 		f_urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
164 		f_urb->interval = 4;
165 		f_urb->context = tascam;
166 		f_urb->complete = feedback_urb_complete;
167 	}
168 
169 	tascam->capture_urb_alloc_size = CAPTURE_URB_SIZE;
170 	for (i = 0; i < NUM_CAPTURE_URBS; i++) {
171 		struct urb *c_urb = usb_alloc_urb(0, GFP_KERNEL);
172 
173 		if (!c_urb)
174 			goto error;
175 		tascam->capture_urbs[i] = c_urb;
176 
177 		c_urb->transfer_buffer = usb_alloc_coherent(
178 			tascam->dev, tascam->capture_urb_alloc_size, GFP_KERNEL,
179 			&c_urb->transfer_dma);
180 		if (!c_urb->transfer_buffer)
181 			goto error;
182 
183 		usb_fill_bulk_urb(c_urb, tascam->dev,
184 				  usb_rcvbulkpipe(tascam->dev, EP_AUDIO_IN),
185 				  c_urb->transfer_buffer,
186 				  tascam->capture_urb_alloc_size,
187 				  capture_urb_complete, tascam);
188 		c_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
189 	}
190 
191 	/* MIDI URB and buffer allocation */
192 	for (i = 0; i < NUM_MIDI_IN_URBS; i++) {
193 		struct urb *m_urb = usb_alloc_urb(0, GFP_KERNEL);
194 
195 		if (!m_urb)
196 			goto error;
197 		tascam->midi_in_urbs[i] = m_urb;
198 		m_urb->transfer_buffer =
199 			usb_alloc_coherent(tascam->dev, MIDI_IN_BUF_SIZE,
200 					   GFP_KERNEL, &m_urb->transfer_dma);
201 		if (!m_urb->transfer_buffer)
202 			goto error;
203 		usb_fill_bulk_urb(m_urb, tascam->dev,
204 				  usb_rcvbulkpipe(tascam->dev, EP_MIDI_IN),
205 				  m_urb->transfer_buffer, MIDI_IN_BUF_SIZE,
206 				  tascam_midi_in_urb_complete, tascam);
207 		m_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
208 	}
209 
210 	for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
211 		struct urb *m_urb = usb_alloc_urb(0, GFP_KERNEL);
212 
213 		if (!m_urb)
214 			goto error;
215 		tascam->midi_out_urbs[i] = m_urb;
216 		m_urb->transfer_buffer =
217 			usb_alloc_coherent(tascam->dev, MIDI_OUT_BUF_SIZE,
218 					   GFP_KERNEL, &m_urb->transfer_dma);
219 		if (!m_urb->transfer_buffer)
220 			goto error;
221 		usb_fill_bulk_urb(m_urb, tascam->dev,
222 				  usb_sndbulkpipe(tascam->dev, EP_MIDI_OUT),
223 				  m_urb->transfer_buffer,
224 				  0, /* length set later */
225 				  tascam_midi_out_urb_complete, tascam);
226 		m_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
227 	}
228 
229 	tascam->capture_ring_buffer =
230 		kmalloc(CAPTURE_RING_BUFFER_SIZE, GFP_KERNEL);
231 	if (!tascam->capture_ring_buffer)
232 		goto error;
233 
234 	tascam->capture_decode_raw_block =
235 		kmalloc(RAW_BYTES_PER_DECODE_BLOCK, GFP_KERNEL);
236 	if (!tascam->capture_decode_raw_block)
237 		goto error;
238 
239 	tascam->capture_decode_dst_block =
240 		kmalloc(FRAMES_PER_DECODE_BLOCK * DECODED_CHANNELS_PER_FRAME *
241 				DECODED_SAMPLE_SIZE,
242 			GFP_KERNEL);
243 	if (!tascam->capture_decode_dst_block)
244 		goto error;
245 
246 	tascam->capture_routing_buffer =
247 		kmalloc(FRAMES_PER_DECODE_BLOCK * DECODED_CHANNELS_PER_FRAME *
248 				DECODED_SAMPLE_SIZE,
249 			GFP_KERNEL);
250 	if (!tascam->capture_routing_buffer)
251 		goto error;
252 
253 	return 0;
254 
255 error:
256 	dev_err(tascam->card->dev, "Failed to allocate URBs\n");
257 	tascam_free_urbs(tascam);
258 	return -ENOMEM;
259 }
260 
261 void tascam_stop_work_handler(struct work_struct *work)
262 {
263 	struct tascam_card *tascam =
264 		container_of(work, struct tascam_card, stop_work);
265 
266 	usb_kill_anchored_urbs(&tascam->playback_anchor);
267 	usb_kill_anchored_urbs(&tascam->feedback_anchor);
268 	usb_kill_anchored_urbs(&tascam->capture_anchor);
269 	atomic_set(&tascam->active_urbs, 0);
270 }
271 
272 /**
273  * tascam_card_private_free() - Frees private data associated with the sound
274  * card.
275  * @card: Pointer to the ALSA sound card instance.
276  *
277  * This function is called when the sound card is being freed. It releases
278  * resources allocated for the tascam_card structure, including the MIDI
279  * input FIFO and decrements the USB device reference count.
280  */
281 static void tascam_card_private_free(struct snd_card *card)
282 {
283 	struct tascam_card *tascam = card->private_data;
284 
285 	if (tascam) {
286 		kfifo_free(&tascam->midi_in_fifo);
287 		if (tascam->dev) {
288 			usb_put_dev(tascam->dev);
289 			tascam->dev = NULL;
290 		}
291 	}
292 }
293 
294 /**
295  * tascam_suspend() - Handles device suspension.
296  * @intf: The USB interface being suspended.
297  * @message: Power management message.
298  *
299  * This function is called when the device is suspended. It stops all active
300  * streams, kills all URBs, and sends a vendor-specific deep sleep command
301  * to the device to ensure a stable low-power state.
302  *
303  * Return: 0 on success.
304  */
305 static int tascam_suspend(struct usb_interface *intf, pm_message_t message)
306 {
307 	struct tascam_card *tascam = usb_get_intfdata(intf);
308 
309 	if (!tascam)
310 		return 0;
311 
312 	snd_pcm_suspend_all(tascam->pcm);
313 
314 	cancel_work_sync(&tascam->stop_work);
315 	cancel_work_sync(&tascam->capture_work);
316 	cancel_work_sync(&tascam->midi_in_work);
317 	cancel_work_sync(&tascam->midi_out_work);
318 	cancel_work_sync(&tascam->stop_pcm_work);
319 	usb_kill_anchored_urbs(&tascam->playback_anchor);
320 	usb_kill_anchored_urbs(&tascam->capture_anchor);
321 	usb_kill_anchored_urbs(&tascam->feedback_anchor);
322 	usb_kill_anchored_urbs(&tascam->midi_in_anchor);
323 	usb_kill_anchored_urbs(&tascam->midi_out_anchor);
324 
325 	dev_info(&intf->dev, "sending deep sleep command\n");
326 	int err = usb_control_msg(tascam->dev, usb_sndctrlpipe(tascam->dev, 0),
327 				  VENDOR_REQ_DEEP_SLEEP, RT_H2D_VENDOR_DEV,
328 				  0x0000, 0x0000, NULL, 0, USB_CTRL_TIMEOUT_MS);
329 	if (err < 0)
330 		dev_err(&intf->dev, "deep sleep command failed: %d\n", err);
331 
332 	return 0;
333 }
334 
335 /**
336  * tascam_resume() - Handles device resumption from suspend.
337  * @intf: The USB interface being resumed.
338  *
339  * This function is called when the device resumes from suspend. It
340  * re-establishes the active USB interface settings and re-configures the sample
341  * rate if it was previously active.
342  *
343  * Return: 0 on success, or a negative error code on failure.
344  */
345 static int tascam_resume(struct usb_interface *intf)
346 {
347 	struct tascam_card *tascam = usb_get_intfdata(intf);
348 	int err;
349 
350 	if (!tascam)
351 		return 0;
352 
353 	dev_info(&intf->dev, "resuming TASCAM US-144MKII\n");
354 
355 	/*
356 	 * The device requires a full re-initialization sequence upon resume.
357 	 * First, re-establish the active USB interface settings.
358 	 */
359 	err = usb_set_interface(tascam->dev, 0, 1);
360 	if (err < 0) {
361 		dev_err(&intf->dev,
362 			"resume: failed to set alt setting on intf 0: %d\n",
363 			err);
364 		return err;
365 	}
366 	err = usb_set_interface(tascam->dev, 1, 1);
367 	if (err < 0) {
368 		dev_err(&intf->dev,
369 			"resume: failed to set alt setting on intf 1: %d\n",
370 			err);
371 		return err;
372 	}
373 
374 	/* Re-configure the sample rate if one was previously active */
375 	if (tascam->current_rate > 0)
376 		us144mkii_configure_device_for_rate(tascam,
377 						    tascam->current_rate);
378 
379 	return 0;
380 }
381 
382 static void tascam_error_timer(struct timer_list *t)
383 {
384 	struct tascam_card *tascam =
385 		container_of(t, struct tascam_card, error_timer);
386 
387 	if (atomic_read(&tascam->midi_in_active))
388 		schedule_work(&tascam->midi_in_work);
389 	if (atomic_read(&tascam->midi_out_active))
390 		schedule_work(&tascam->midi_out_work);
391 }
392 
393 /**
394  * tascam_probe() - Probes for the TASCAM US-144MKII device.
395  * @intf: The USB interface being probed.
396  * @usb_id: The USB device ID.
397  *
398  * This function is the entry point for the USB driver when a matching device
399  * is found. It performs initial device setup, including:
400  * - Checking for the second interface (MIDI) and associating it.
401  * - Performing a vendor-specific handshake with the device.
402  * - Setting alternate settings for USB interfaces.
403  * - Creating and registering the ALSA sound card, PCM device, and MIDI device.
404  * - Allocating and initializing URBs for audio and MIDI transfers.
405  *
406  * Return: 0 on success, or a negative error code on failure.
407  */
408 static int tascam_probe(struct usb_interface *intf,
409 			const struct usb_device_id *usb_id)
410 {
411 	struct usb_device *dev = interface_to_usbdev(intf);
412 	struct snd_card *card;
413 	struct tascam_card *tascam;
414 	int err;
415 	char *handshake_buf __free(kfree) = NULL;
416 
417 	if (dev->speed != USB_SPEED_HIGH)
418 		dev_info(
419 			&dev->dev,
420 			"Device is connected to a USB 1.1 port, this is not supported.\n");
421 
422 	/* The device has two interfaces; we drive both from this driver. */
423 	if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {
424 		tascam = usb_get_intfdata(usb_ifnum_to_if(dev, 0));
425 		if (tascam) {
426 			usb_set_intfdata(intf, tascam);
427 			tascam->iface1 = intf;
428 		}
429 		return 0; /* Let the core handle this interface */
430 	}
431 
432 	if (dev_idx >= SNDRV_CARDS) {
433 		dev_err(&dev->dev, "Too many TASCAM devices present");
434 		return -ENODEV;
435 	}
436 
437 	if (!enable[dev_idx]) {
438 		dev_info(&dev->dev, "TASCAM US-144MKII device disabled");
439 		return -ENOENT;
440 	}
441 
442 	handshake_buf = kmalloc(1, GFP_KERNEL);
443 	if (!handshake_buf)
444 		return -ENOMEM;
445 
446 	/* Perform vendor-specific handshake */
447 	err = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
448 			      VENDOR_REQ_MODE_CONTROL, RT_D2H_VENDOR_DEV,
449 			      MODE_VAL_HANDSHAKE_READ, 0x0000, handshake_buf, 1,
450 			      USB_CTRL_TIMEOUT_MS);
451 	if (err < 0) {
452 		dev_err(&dev->dev, "Handshake read failed with %d\n", err);
453 		return err;
454 	}
455 
456 	if (handshake_buf[0] != 0x12 && handshake_buf[0] != 0x16 &&
457 	    handshake_buf[0] != 0x30 && handshake_buf[0] != 0x32) {
458 		dev_err(&dev->dev, "Unexpected handshake value: 0x%x\n",
459 			handshake_buf[0]);
460 		return -ENODEV;
461 	}
462 
463 	/* Set alternate settings to enable audio/MIDI endpoints */
464 	err = usb_set_interface(dev, 0, 1);
465 	if (err < 0) {
466 		dev_err(&dev->dev,
467 			"Failed to set alt setting 1 on interface 0: %d\n",
468 			err);
469 		return err;
470 	}
471 
472 	err = usb_set_interface(dev, 1, 1);
473 	if (err < 0) {
474 		dev_err(&dev->dev,
475 			"Failed to set alt setting 1 on interface 1: %d\n",
476 			err);
477 		return err;
478 	}
479 
480 	err = snd_card_new(&dev->dev, index[dev_idx], id[dev_idx], THIS_MODULE,
481 			   sizeof(struct tascam_card), &card);
482 	if (err < 0) {
483 		dev_err(&dev->dev, "Failed to create sound card instance\n");
484 		return err;
485 	}
486 
487 	tascam = card->private_data;
488 	card->private_free = tascam_card_private_free;
489 	tascam->dev = usb_get_dev(dev);
490 	tascam->card = card;
491 	tascam->iface0 = intf;
492 	tascam->digital_out_source = 1;
493 	tascam->capture_34_source = 1;
494 
495 	spin_lock_init(&tascam->lock);
496 	spin_lock_init(&tascam->midi_in_lock);
497 	spin_lock_init(&tascam->midi_out_lock);
498 	init_usb_anchor(&tascam->playback_anchor);
499 	init_usb_anchor(&tascam->capture_anchor);
500 	init_usb_anchor(&tascam->feedback_anchor);
501 	init_usb_anchor(&tascam->midi_in_anchor);
502 	init_usb_anchor(&tascam->midi_out_anchor);
503 
504 	timer_setup(&tascam->error_timer, tascam_error_timer, 0);
505 
506 	INIT_WORK(&tascam->stop_work, tascam_stop_work_handler);
507 	INIT_WORK(&tascam->stop_pcm_work, tascam_stop_pcm_work_handler);
508 	INIT_WORK(&tascam->capture_work, tascam_capture_work_handler);
509 	init_completion(&tascam->midi_out_drain_completion);
510 
511 	if (kfifo_alloc(&tascam->midi_in_fifo, MIDI_IN_FIFO_SIZE, GFP_KERNEL)) {
512 		snd_card_free(card);
513 		return -ENOMEM;
514 	}
515 
516 	strscpy(card->driver, DRIVER_NAME, sizeof(card->driver));
517 	if (le16_to_cpu(dev->descriptor.idProduct) == USB_PID_TASCAM_US144) {
518 		strscpy(card->shortname, "TASCAM US-144",
519 			sizeof(card->shortname));
520 	} else if (le16_to_cpu(dev->descriptor.idProduct) == USB_PID_TASCAM_US144MKII) {
521 		strscpy(card->shortname, "TASCAM US-144MKII",
522 			sizeof(card->shortname));
523 	} else {
524 		strscpy(card->shortname, "TASCAM Unknown",
525 			sizeof(card->shortname));
526 	}
527 	snprintf(card->longname, sizeof(card->longname), "%s (%04x:%04x) at %s",
528 		 card->shortname, USB_VID_TASCAM, dev->descriptor.idProduct,
529 		 dev_name(&dev->dev));
530 
531 	err = snd_pcm_new(card, "US144MKII PCM", 0, 1, 1, &tascam->pcm);
532 	if (err < 0)
533 		goto free_card;
534 	tascam->pcm->private_data = tascam;
535 	strscpy(tascam->pcm->name, "US144MKII PCM", sizeof(tascam->pcm->name));
536 
537 	err = tascam_init_pcm(tascam->pcm);
538 	if (err < 0)
539 		goto free_card;
540 
541 	err = tascam_create_midi(tascam);
542 	if (err < 0)
543 		goto free_card;
544 
545 	err = tascam_create_controls(tascam);
546 	if (err < 0)
547 		goto free_card;
548 
549 	err = tascam_alloc_urbs(tascam);
550 	if (err < 0)
551 		goto free_card;
552 
553 	err = snd_card_register(card);
554 	if (err < 0)
555 		goto free_card;
556 
557 	usb_set_intfdata(intf, tascam);
558 
559 	dev_idx++;
560 	return 0;
561 
562 free_card:
563 	tascam_free_urbs(tascam);
564 	snd_card_free(card);
565 	return err;
566 }
567 
568 /**
569  * tascam_disconnect() - Disconnects the TASCAM US-144MKII device.
570  * @intf: The USB interface being disconnected.
571  *
572  * This function is called when the device is disconnected from the system.
573  * It cleans up all allocated resources, including killing URBs, freeing
574  * the sound card, and releasing memory.
575  */
576 static void tascam_disconnect(struct usb_interface *intf)
577 {
578 	struct tascam_card *tascam = usb_get_intfdata(intf);
579 
580 	if (!tascam)
581 		return;
582 
583 	if (intf->cur_altsetting->desc.bInterfaceNumber == 0) {
584 		/* Ensure all deferred work is complete before freeing resources */
585 		snd_card_disconnect(tascam->card);
586 		cancel_work_sync(&tascam->stop_work);
587 		cancel_work_sync(&tascam->capture_work);
588 		cancel_work_sync(&tascam->midi_in_work);
589 		cancel_work_sync(&tascam->midi_out_work);
590 		cancel_work_sync(&tascam->stop_pcm_work);
591 
592 		usb_kill_anchored_urbs(&tascam->playback_anchor);
593 		usb_kill_anchored_urbs(&tascam->capture_anchor);
594 		usb_kill_anchored_urbs(&tascam->feedback_anchor);
595 		usb_kill_anchored_urbs(&tascam->midi_in_anchor);
596 		usb_kill_anchored_urbs(&tascam->midi_out_anchor);
597 		timer_delete_sync(&tascam->error_timer);
598 		tascam_free_urbs(tascam);
599 		snd_card_free(tascam->card);
600 		dev_idx--;
601 	}
602 }
603 
604 static const struct usb_device_id tascam_usb_ids[] = {
605 	{ USB_DEVICE(USB_VID_TASCAM, USB_PID_TASCAM_US144) },
606 	{ USB_DEVICE(USB_VID_TASCAM, USB_PID_TASCAM_US144MKII) },
607 	{ /* Terminating entry */ }
608 };
609 MODULE_DEVICE_TABLE(usb, tascam_usb_ids);
610 
611 static struct usb_driver tascam_alsa_driver = {
612 	.name = DRIVER_NAME,
613 	.probe = tascam_probe,
614 	.disconnect = tascam_disconnect,
615 	.suspend = tascam_suspend,
616 	.resume = tascam_resume,
617 	.id_table = tascam_usb_ids,
618 };
619 
620 module_usb_driver(tascam_alsa_driver);
621