2 * f_midi.c -- USB MIDI class function driver
4 * Copyright (C) 2006 Thumtronics Pty Ltd.
5 * Developed for Thumtronics by Grey Innovation
6 * Ben Williamson <ben.williamson@greyinnovation.com>
8 * Rewritten for the composite framework
9 * Copyright (C) 2011 Daniel Mack <zonque@gmail.com>
11 * Based on drivers/usb/gadget/f_audio.c,
12 * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
13 * Copyright (C) 2008 Analog Devices, Inc
15 * and drivers/usb/gadget/midi.c,
16 * Copyright (C) 2006 Thumtronics Pty Ltd.
17 * Ben Williamson <ben.williamson@greyinnovation.com>
19 * Licensed under the GPL-2 or later.
22 #include <linux/kernel.h>
23 #include <linux/slab.h>
24 #include <linux/utsname.h>
25 #include <linux/device.h>
27 #include <sound/core.h>
28 #include <sound/initval.h>
29 #include <sound/rawmidi.h>
31 #include <linux/usb/ch9.h>
32 #include <linux/usb/gadget.h>
33 #include <linux/usb/audio.h>
34 #include <linux/usb/midi.h>
36 MODULE_AUTHOR("Ben Williamson");
37 MODULE_LICENSE("GPL v2");
39 static const char f_midi_shortname[] = "f_midi";
40 static const char f_midi_longname[] = "MIDI Gadget";
43 * This is a gadget, and the IN/OUT naming is from the host's perspective.
44 * USB -> OUT endpoint -> rawmidi
45 * USB <- IN endpoint <- rawmidi
47 struct gmidi_in_port {
50 uint8_t cable; /* cable number << 4 */
52 #define STATE_UNKNOWN 0
53 #define STATE_1PARAM 1
54 #define STATE_2PARAM_1 2
55 #define STATE_2PARAM_2 3
56 #define STATE_SYSEX_0 4
57 #define STATE_SYSEX_1 5
58 #define STATE_SYSEX_2 6
63 struct usb_function func;
64 struct usb_gadget *gadget;
65 struct usb_ep *in_ep, *out_ep;
66 struct snd_card *card;
67 struct snd_rawmidi *rmidi;
68 struct snd_rawmidi_substream *in_substream;
69 struct snd_rawmidi_substream *out_substream;
71 /* For the moment we only support one port in
72 each direction, but in_port is kept as a
73 separate struct so we can have more later. */
74 struct gmidi_in_port in_port;
75 unsigned long out_triggered;
76 struct tasklet_struct tasklet;
79 unsigned int buflen, qlen;
82 static inline struct f_midi *func_to_midi(struct usb_function *f)
84 return container_of(f, struct f_midi, func);
87 static void f_midi_transmit(struct f_midi *midi, struct usb_request *req);
89 DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
90 DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
91 DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(1);
93 /* B.3.1 Standard AC Interface Descriptor */
94 static struct usb_interface_descriptor ac_interface_desc __initdata = {
95 .bLength = USB_DT_INTERFACE_SIZE,
96 .bDescriptorType = USB_DT_INTERFACE,
97 /* .bInterfaceNumber = DYNAMIC */
98 /* .bNumEndpoints = DYNAMIC */
99 .bInterfaceClass = USB_CLASS_AUDIO,
100 .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
101 /* .iInterface = DYNAMIC */
104 /* B.3.2 Class-Specific AC Interface Descriptor */
105 static struct uac1_ac_header_descriptor_1 ac_header_desc __initdata = {
106 .bLength = UAC_DT_AC_HEADER_SIZE(1),
107 .bDescriptorType = USB_DT_CS_INTERFACE,
108 .bDescriptorSubtype = USB_MS_HEADER,
109 .bcdADC = cpu_to_le16(0x0100),
110 .wTotalLength = cpu_to_le16(UAC_DT_AC_HEADER_SIZE(1)),
112 /* .baInterfaceNr = DYNAMIC */
115 /* B.4.1 Standard MS Interface Descriptor */
116 static struct usb_interface_descriptor ms_interface_desc __initdata = {
117 .bLength = USB_DT_INTERFACE_SIZE,
118 .bDescriptorType = USB_DT_INTERFACE,
119 /* .bInterfaceNumber = DYNAMIC */
121 .bInterfaceClass = USB_CLASS_AUDIO,
122 .bInterfaceSubClass = USB_SUBCLASS_MIDISTREAMING,
123 /* .iInterface = DYNAMIC */
126 /* B.4.2 Class-Specific MS Interface Descriptor */
127 static struct usb_ms_header_descriptor ms_header_desc __initdata = {
128 .bLength = USB_DT_MS_HEADER_SIZE,
129 .bDescriptorType = USB_DT_CS_INTERFACE,
130 .bDescriptorSubtype = USB_MS_HEADER,
131 .bcdMSC = cpu_to_le16(0x0100),
132 .wTotalLength = cpu_to_le16(USB_DT_MS_HEADER_SIZE
133 + 2*USB_DT_MIDI_IN_SIZE
134 + 2*USB_DT_MIDI_OUT_SIZE(1)),
137 #define JACK_IN_EMB 1
138 #define JACK_IN_EXT 2
139 #define JACK_OUT_EMB 3
140 #define JACK_OUT_EXT 4
142 /* B.4.3 MIDI IN Jack Descriptors */
143 static const struct usb_midi_in_jack_descriptor jack_in_emb_desc = {
144 .bLength = USB_DT_MIDI_IN_SIZE,
145 .bDescriptorType = USB_DT_CS_INTERFACE,
146 .bDescriptorSubtype = USB_MS_MIDI_IN_JACK,
147 .bJackType = USB_MS_EMBEDDED,
148 .bJackID = JACK_IN_EMB,
151 static const struct usb_midi_in_jack_descriptor jack_in_ext_desc = {
152 .bLength = USB_DT_MIDI_IN_SIZE,
153 .bDescriptorType = USB_DT_CS_INTERFACE,
154 .bDescriptorSubtype = USB_MS_MIDI_IN_JACK,
155 .bJackType = USB_MS_EXTERNAL,
156 .bJackID = JACK_IN_EXT,
159 /* B.4.4 MIDI OUT Jack Descriptors */
160 static const struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc = {
161 .bLength = USB_DT_MIDI_OUT_SIZE(1),
162 .bDescriptorType = USB_DT_CS_INTERFACE,
163 .bDescriptorSubtype = USB_MS_MIDI_OUT_JACK,
164 .bJackType = USB_MS_EMBEDDED,
165 .bJackID = JACK_OUT_EMB,
169 .baSourceID = JACK_IN_EXT,
175 static const struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc = {
176 .bLength = USB_DT_MIDI_OUT_SIZE(1),
177 .bDescriptorType = USB_DT_CS_INTERFACE,
178 .bDescriptorSubtype = USB_MS_MIDI_OUT_JACK,
179 .bJackType = USB_MS_EXTERNAL,
180 .bJackID = JACK_OUT_EXT,
184 .baSourceID = JACK_IN_EMB,
190 /* B.5.1 Standard Bulk OUT Endpoint Descriptor */
191 static struct usb_endpoint_descriptor bulk_out_desc = {
192 .bLength = USB_DT_ENDPOINT_AUDIO_SIZE,
193 .bDescriptorType = USB_DT_ENDPOINT,
194 .bEndpointAddress = USB_DIR_OUT,
195 .bmAttributes = USB_ENDPOINT_XFER_BULK,
198 /* B.5.2 Class-specific MS Bulk OUT Endpoint Descriptor */
199 static const struct usb_ms_endpoint_descriptor_1 ms_out_desc = {
200 .bLength = USB_DT_MS_ENDPOINT_SIZE(1),
201 .bDescriptorType = USB_DT_CS_ENDPOINT,
202 .bDescriptorSubtype = USB_MS_GENERAL,
203 .bNumEmbMIDIJack = 1,
209 /* B.6.1 Standard Bulk IN Endpoint Descriptor */
210 static struct usb_endpoint_descriptor bulk_in_desc = {
211 .bLength = USB_DT_ENDPOINT_AUDIO_SIZE,
212 .bDescriptorType = USB_DT_ENDPOINT,
213 .bEndpointAddress = USB_DIR_IN,
214 .bmAttributes = USB_ENDPOINT_XFER_BULK,
217 /* B.6.2 Class-specific MS Bulk IN Endpoint Descriptor */
218 static const struct usb_ms_endpoint_descriptor_1 ms_in_desc = {
219 .bLength = USB_DT_MS_ENDPOINT_SIZE(1),
220 .bDescriptorType = USB_DT_CS_ENDPOINT,
221 .bDescriptorSubtype = USB_MS_GENERAL,
222 .bNumEmbMIDIJack = 1,
228 static struct usb_descriptor_header *midi_function[] = {
229 (struct usb_descriptor_header *)&ac_interface_desc,
230 (struct usb_descriptor_header *)&ac_header_desc,
231 (struct usb_descriptor_header *)&ms_interface_desc,
233 (struct usb_descriptor_header *)&ms_header_desc,
234 (struct usb_descriptor_header *)&jack_in_emb_desc,
235 (struct usb_descriptor_header *)&jack_in_ext_desc,
236 (struct usb_descriptor_header *)&jack_out_emb_desc,
237 (struct usb_descriptor_header *)&jack_out_ext_desc,
238 /* If you add more jacks, update ms_header_desc.wTotalLength */
240 (struct usb_descriptor_header *)&bulk_out_desc,
241 (struct usb_descriptor_header *)&ms_out_desc,
242 (struct usb_descriptor_header *)&bulk_in_desc,
243 (struct usb_descriptor_header *)&ms_in_desc,
247 /* string IDs are assigned dynamically */
249 #define STRING_FUNC_IDX 0
251 static struct usb_string midi_string_defs[] = {
252 [STRING_FUNC_IDX].s = "MIDI function",
253 { } /* end of list */
256 static struct usb_gadget_strings midi_stringtab = {
257 .language = 0x0409, /* en-us */
258 .strings = midi_string_defs,
261 static struct usb_gadget_strings *midi_strings[] = {
266 static struct usb_request *alloc_ep_req(struct usb_ep *ep, unsigned length)
268 struct usb_request *req;
270 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
272 req->length = length;
273 req->buf = kmalloc(length, GFP_ATOMIC);
275 usb_ep_free_request(ep, req);
282 static void free_ep_req(struct usb_ep *ep, struct usb_request *req)
285 usb_ep_free_request(ep, req);
288 static const uint8_t f_midi_cin_length[] = {
289 0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
293 * Receives a chunk of MIDI data.
295 static void f_midi_read_data(struct usb_ep *ep, int cable,
296 uint8_t *data, int length)
298 struct f_midi *midi = ep->driver_data;
299 /* cable is ignored, because for now we only have one. */
301 if (!midi->out_substream)
302 /* Nobody is listening - throw it on the floor. */
305 if (!test_bit(midi->out_substream->number, &midi->out_triggered))
308 snd_rawmidi_receive(midi->out_substream, data, length);
311 static void f_midi_handle_out_data(struct usb_ep *ep, struct usb_request *req)
316 for (i = 0; i + 3 < req->actual; i += 4)
318 int cable = buf[i] >> 4;
319 int length = f_midi_cin_length[buf[i] & 0x0f];
320 f_midi_read_data(ep, cable, &buf[i + 1], length);
325 f_midi_complete(struct usb_ep *ep, struct usb_request *req)
327 struct f_midi *midi = ep->driver_data;
328 struct usb_composite_dev *cdev = midi->func.config->cdev;
329 int status = req->status;
332 case 0: /* normal completion */
333 if (ep == midi->out_ep) {
334 /* We received stuff. req is queued again, below */
335 f_midi_handle_out_data(ep, req);
336 } else if (ep == midi->in_ep) {
337 /* Our transmit completed. See if there's more to go.
338 * f_midi_transmit eats req, don't queue it again. */
339 f_midi_transmit(midi, req);
344 /* this endpoint is normally active while we're configured */
345 case -ECONNABORTED: /* hardware forced ep reset */
346 case -ECONNRESET: /* request dequeued */
347 case -ESHUTDOWN: /* disconnect from host */
348 VDBG(cdev, "%s gone (%d), %d/%d\n", ep->name, status,
349 req->actual, req->length);
350 if (ep == midi->out_ep)
351 f_midi_handle_out_data(ep, req);
353 free_ep_req(ep, req);
356 case -EOVERFLOW: /* buffer overrun on read means that
357 * we didn't provide a big enough buffer.
360 DBG(cdev, "%s complete --> %d, %d/%d\n", ep->name,
361 status, req->actual, req->length);
363 case -EREMOTEIO: /* short read */
367 status = usb_ep_queue(ep, req, GFP_ATOMIC);
369 ERROR(cdev, "kill %s: resubmit %d bytes --> %d\n",
370 ep->name, req->length, status);
372 /* FIXME recover later ... somehow */
376 static int f_midi_start_ep(struct f_midi *midi,
377 struct usb_function *f,
381 struct usb_composite_dev *cdev = f->config->cdev;
386 err = config_ep_by_speed(midi->gadget, f, ep);
388 ERROR(cdev, "can't configure %s: %d\n", ep->name, err);
392 err = usb_ep_enable(ep);
394 ERROR(cdev, "can't start %s: %d\n", ep->name, err);
398 ep->driver_data = midi;
403 static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
405 struct f_midi *midi = func_to_midi(f);
406 struct usb_composite_dev *cdev = f->config->cdev;
410 err = f_midi_start_ep(midi, f, midi->in_ep);
414 err = f_midi_start_ep(midi, f, midi->out_ep);
418 if (midi->out_ep->driver_data)
419 usb_ep_disable(midi->out_ep);
421 err = config_ep_by_speed(midi->gadget, f, midi->out_ep);
423 ERROR(cdev, "can't configure %s: %d\n",
424 midi->out_ep->name, err);
428 err = usb_ep_enable(midi->out_ep);
430 ERROR(cdev, "can't start %s: %d\n",
431 midi->out_ep->name, err);
435 midi->out_ep->driver_data = midi;
437 /* allocate a bunch of read buffers and queue them all at once. */
438 for (i = 0; i < midi->qlen && err == 0; i++) {
439 struct usb_request *req =
440 alloc_ep_req(midi->out_ep, midi->buflen);
444 req->complete = f_midi_complete;
445 err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC);
447 ERROR(midi, "%s queue req: %d\n",
448 midi->out_ep->name, err);
455 static void f_midi_disable(struct usb_function *f)
457 struct f_midi *midi = func_to_midi(f);
458 struct usb_composite_dev *cdev = f->config->cdev;
460 DBG(cdev, "disable\n");
463 * just disable endpoints, forcing completion of pending i/o.
464 * all our completion handlers free their requests in this case.
466 usb_ep_disable(midi->in_ep);
467 usb_ep_disable(midi->out_ep);
470 static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
472 struct usb_composite_dev *cdev = f->config->cdev;
473 struct f_midi *midi = func_to_midi(f);
474 struct snd_card *card;
476 DBG(cdev, "unbind\n");
478 /* just to be sure */
489 usb_free_descriptors(f->descriptors);
493 static int f_midi_snd_free(struct snd_device *device)
498 static void f_midi_transmit_packet(struct usb_request *req, uint8_t p0,
499 uint8_t p1, uint8_t p2, uint8_t p3)
501 unsigned length = req->length;
502 u8 *buf = (u8 *)req->buf + length;
508 req->length = length + 4;
512 * Converts MIDI commands to USB MIDI packets.
514 static void f_midi_transmit_byte(struct usb_request *req,
515 struct gmidi_in_port *port, uint8_t b)
517 uint8_t p0 = port->cable;
520 f_midi_transmit_packet(req, p0 | 0x0f, b, 0, 0);
521 } else if (b >= 0xf0) {
525 port->state = STATE_SYSEX_1;
530 port->state = STATE_1PARAM;
534 port->state = STATE_2PARAM_1;
538 port->state = STATE_UNKNOWN;
541 f_midi_transmit_packet(req, p0 | 0x05, 0xf6, 0, 0);
542 port->state = STATE_UNKNOWN;
545 switch (port->state) {
547 f_midi_transmit_packet(req,
548 p0 | 0x05, 0xf7, 0, 0);
551 f_midi_transmit_packet(req,
552 p0 | 0x06, port->data[0], 0xf7, 0);
555 f_midi_transmit_packet(req,
556 p0 | 0x07, port->data[0],
557 port->data[1], 0xf7);
560 port->state = STATE_UNKNOWN;
563 } else if (b >= 0x80) {
565 if (b >= 0xc0 && b <= 0xdf)
566 port->state = STATE_1PARAM;
568 port->state = STATE_2PARAM_1;
569 } else { /* b < 0x80 */
570 switch (port->state) {
572 if (port->data[0] < 0xf0) {
573 p0 |= port->data[0] >> 4;
576 port->state = STATE_UNKNOWN;
578 f_midi_transmit_packet(req, p0, port->data[0], b, 0);
582 port->state = STATE_2PARAM_2;
585 if (port->data[0] < 0xf0) {
586 p0 |= port->data[0] >> 4;
587 port->state = STATE_2PARAM_1;
590 port->state = STATE_UNKNOWN;
592 f_midi_transmit_packet(req,
593 p0, port->data[0], port->data[1], b);
597 port->state = STATE_SYSEX_1;
601 port->state = STATE_SYSEX_2;
604 f_midi_transmit_packet(req,
605 p0 | 0x04, port->data[0], port->data[1], b);
606 port->state = STATE_SYSEX_0;
612 static void f_midi_transmit(struct f_midi *midi, struct usb_request *req)
614 struct usb_ep *ep = midi->in_ep;
615 struct gmidi_in_port *port = &midi->in_port;
621 req = alloc_ep_req(ep, midi->buflen);
624 ERROR(midi, "gmidi_transmit: alloc_ep_request failed\n");
628 req->complete = f_midi_complete;
631 while (req->length + 3 < midi->buflen) {
633 if (snd_rawmidi_transmit(midi->in_substream, &b, 1) != 1) {
637 f_midi_transmit_byte(req, port, b);
642 usb_ep_queue(ep, req, GFP_ATOMIC);
644 free_ep_req(ep, req);
647 static void f_midi_in_tasklet(unsigned long data)
649 struct f_midi *midi = (struct f_midi *) data;
650 f_midi_transmit(midi, NULL);
653 static int f_midi_in_open(struct snd_rawmidi_substream *substream)
655 struct f_midi *midi = substream->rmidi->private_data;
657 VDBG(midi, "%s()\n", __func__);
658 midi->in_substream = substream;
659 midi->in_port.state = STATE_UNKNOWN;
663 static int f_midi_in_close(struct snd_rawmidi_substream *substream)
665 struct f_midi *midi = substream->rmidi->private_data;
667 VDBG(midi, "%s()\n", __func__);
671 static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up)
673 struct f_midi *midi = substream->rmidi->private_data;
675 VDBG(midi, "%s() %d\n", __func__, up);
676 midi->in_port.active = up;
678 tasklet_hi_schedule(&midi->tasklet);
681 static int f_midi_out_open(struct snd_rawmidi_substream *substream)
683 struct f_midi *midi = substream->rmidi->private_data;
685 VDBG(midi, "%s()\n", __func__);
686 midi->out_substream = substream;
690 static int f_midi_out_close(struct snd_rawmidi_substream *substream)
692 struct f_midi *midi = substream->rmidi->private_data;
694 VDBG(midi, "%s()\n", __func__);
698 static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up)
700 struct f_midi *midi = substream->rmidi->private_data;
702 VDBG(midi, "%s()\n", __func__);
705 set_bit(substream->number, &midi->out_triggered);
707 clear_bit(substream->number, &midi->out_triggered);
710 static struct snd_rawmidi_ops gmidi_in_ops = {
711 .open = f_midi_in_open,
712 .close = f_midi_in_close,
713 .trigger = f_midi_in_trigger,
716 static struct snd_rawmidi_ops gmidi_out_ops = {
717 .open = f_midi_out_open,
718 .close = f_midi_out_close,
719 .trigger = f_midi_out_trigger
722 /* register as a sound "card" */
723 static int f_midi_register_card(struct f_midi *midi)
725 struct snd_card *card;
726 struct snd_rawmidi *rmidi;
730 static struct snd_device_ops ops = {
731 .dev_free = f_midi_snd_free,
734 err = snd_card_create(midi->index, midi->id, THIS_MODULE, 0, &card);
736 ERROR(midi, "snd_card_create() failed\n");
741 err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, midi, &ops);
743 ERROR(midi, "snd_device_new() failed: error %d\n", err);
747 strcpy(card->driver, f_midi_longname);
748 strcpy(card->longname, f_midi_longname);
749 strcpy(card->shortname, f_midi_shortname);
752 midi->in_port.midi = midi;
753 midi->in_port.active = 0;
754 snd_component_add(card, "MIDI");
755 err = snd_rawmidi_new(card, card->longname, 0,
756 out_ports, in_ports, &rmidi);
758 ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err);
762 strcpy(rmidi->name, card->shortname);
763 rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
764 SNDRV_RAWMIDI_INFO_INPUT |
765 SNDRV_RAWMIDI_INFO_DUPLEX;
766 rmidi->private_data = midi;
769 * Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
770 * It's an upside-down world being a gadget.
772 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops);
773 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops);
775 snd_card_set_dev(card, &midi->gadget->dev);
777 /* register it - we're ready to go */
778 err = snd_card_register(card);
780 ERROR(midi, "snd_card_register() failed\n");
784 VDBG(midi, "%s() finished ok\n", __func__);
789 snd_card_free(midi->card);
795 /* MIDI function driver setup/binding */
798 f_midi_bind(struct usb_configuration *c, struct usb_function *f)
800 struct usb_composite_dev *cdev = c->cdev;
801 struct f_midi *midi = func_to_midi(f);
804 /* maybe allocate device-global string ID */
805 if (midi_string_defs[0].id == 0) {
806 status = usb_string_id(c->cdev);
809 midi_string_defs[0].id = status;
812 /* We have two interfaces, AudioControl and MIDIStreaming */
813 status = usb_interface_id(c, f);
816 ac_interface_desc.bInterfaceNumber = status;
818 status = usb_interface_id(c, f);
821 ms_interface_desc.bInterfaceNumber = status;
822 ac_header_desc.baInterfaceNr[0] = status;
826 /* allocate instance-specific endpoints */
827 midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
830 midi->in_ep->driver_data = cdev; /* claim */
832 midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc);
835 midi->out_ep->driver_data = cdev; /* claim */
838 * support all relevant hardware speeds... we expect that when
839 * hardware is dual speed, all bulk-capable endpoints work at
842 /* copy descriptors, and track endpoint copies */
843 if (gadget_is_dualspeed(c->cdev->gadget)) {
845 bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
846 bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
847 f->hs_descriptors = usb_copy_descriptors(midi_function);
849 f->descriptors = usb_copy_descriptors(midi_function);
855 /* we might as well release our claims on endpoints */
857 midi->out_ep->driver_data = NULL;
859 midi->in_ep->driver_data = NULL;
861 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
867 * f_midi_bind_config - add USB MIDI function to a configuration
868 * @c: the configuration to supcard the USB audio function
869 * @index: the soundcard index to use for the ALSA device creation
870 * @id: the soundcard id to use for the ALSA device creation
871 * @buflen: the buffer length to use
872 * @qlen the number of read requests to pre-allocate
873 * Context: single threaded during gadget setup
875 * Returns zero on success, else negative errno.
877 int __init f_midi_bind_config(struct usb_configuration *c,
885 /* allocate and initialize one new instance */
886 midi = kzalloc(sizeof *midi, GFP_KERNEL);
892 midi->gadget = c->cdev->gadget;
893 tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);
895 /* set up ALSA midi devices */
896 status = f_midi_register_card(midi);
900 midi->func.name = "gmidi function";
901 midi->func.strings = midi_strings;
902 midi->func.bind = f_midi_bind;
903 midi->func.unbind = f_midi_unbind;
904 midi->func.set_alt = f_midi_set_alt;
905 midi->func.disable = f_midi_disable;
907 midi->id = kstrdup(id, GFP_KERNEL);
909 midi->buflen = buflen;
912 status = usb_add_function(c, &midi->func);