// SPDX-License-Identifier: GPL-2.0+
/*
* f_midi.c -- USB MIDI class function driver
*
* Copyright (C) 2006 Thumtronics Pty Ltd.
* Developed for Thumtronics by Grey Innovation
* Ben Williamson <[email protected]>
*
* Rewritten for the composite framework
* Copyright (C) 2011 Daniel Mack <[email protected]>
*
* Based on drivers/usb/gadget/f_audio.c,
* Copyright (C) 2008 Bryan Wu <[email protected]>
* Copyright (C) 2008 Analog Devices, Inc
*
* and drivers/usb/gadget/midi.c,
* Copyright (C) 2006 Thumtronics Pty Ltd.
* Ben Williamson <[email protected]>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/kfifo.h>
#include <linux/spinlock.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/rawmidi.h>
#include <linux/usb/ch9.h>
#include <linux/usb/func_utils.h>
#include <linux/usb/gadget.h>
#include <linux/usb/audio.h>
#include <linux/usb/midi.h>
#include "u_midi.h"
MODULE_AUTHOR("Ben Williamson");
MODULE_DESCRIPTION("USB MIDI class function driver");
MODULE_LICENSE("GPL v2");
static const char f_midi_shortname[] = "f_midi";
static const char f_midi_longname[] = "MIDI Gadget";
/*
* We can only handle 16 cables on one single endpoint, as cable numbers are
* stored in 4-bit fields. And as the interface currently only holds one
* single endpoint, this is the maximum number of ports we can allow.
*/
#define MAX_PORTS 16
/* MIDI message states */
enum {
STATE_INITIAL = 0, /* pseudo state */
STATE_1PARAM,
STATE_2PARAM_1,
STATE_2PARAM_2,
STATE_SYSEX_0,
STATE_SYSEX_1,
STATE_SYSEX_2,
STATE_REAL_TIME,
STATE_FINISHED, /* pseudo state */
};
/*
* This is a gadget, and the IN/OUT naming is from the host's perspective.
* USB -> OUT endpoint -> rawmidi
* USB <- IN endpoint <- rawmidi
*/
struct gmidi_in_port {
struct snd_rawmidi_substream *substream;
int active;
uint8_t cable;
uint8_t state;
uint8_t data[2];
};
struct f_midi {
struct usb_function func;
struct usb_gadget *gadget;
struct usb_ep *in_ep, *out_ep;
struct snd_card *card;
struct snd_rawmidi *rmidi;
u8 ms_id;
struct snd_rawmidi_substream *out_substream[MAX_PORTS];
unsigned long out_triggered;
struct work_struct work;
unsigned int in_ports;
unsigned int out_ports;
int index;
char *id;
unsigned int buflen, qlen;
/* This fifo is used as a buffer ring for pre-allocated IN usb_requests */
DECLARE_KFIFO_PTR(in_req_fifo, struct usb_request *);
spinlock_t transmit_lock;
unsigned int in_last_port;
unsigned char free_ref;
struct gmidi_in_port in_ports_array[] __counted_by(in_ports);
};
static inline struct f_midi *func_to_midi(struct usb_function *f)
{
return container_of(f, struct f_midi, func);
}
static void f_midi_transmit(struct f_midi *midi);
static void f_midi_rmidi_free(struct snd_rawmidi *rmidi);
static void f_midi_free_inst(struct usb_function_instance *f);
DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16);
/* B.3.1 Standard AC Interface Descriptor */
static struct usb_interface_descriptor ac_interface_desc = {
.bLength = USB_DT_INTERFACE_SIZE,
.bDescriptorType = USB_DT_INTERFACE,
/* .bInterfaceNumber = DYNAMIC */
/* .bNumEndpoints = DYNAMIC */
.bInterfaceClass = USB_CLASS_AUDIO,
.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
/* .iInterface = DYNAMIC */
};
/* B.3.2 Class-Specific AC Interface Descriptor */
static struct uac1_ac_header_descriptor_1 ac_header_desc = {
.bLength = UAC_DT_AC_HEADER_SIZE(1),
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubtype = USB_MS_HEADER,
.bcdADC = cpu_to_le16(0x0100),
.wTotalLength = cpu_to_le16(UAC_DT_AC_HEADER_SIZE(1)),
.bInCollection = 1,
/* .baInterfaceNr = DYNAMIC */
};
/* B.4.1 Standard MS Interface Descriptor */
static struct usb_interface_descriptor ms_interface_desc = {
.bLength = USB_DT_INTERFACE_SIZE,
.bDescriptorType = USB_DT_INTERFACE,
/* .bInterfaceNumber = DYNAMIC */
.bNumEndpoints = 2,
.bInterfaceClass = USB_CLASS_AUDIO,
.bInterfaceSubClass = USB_SUBCLASS_MIDISTREAMING,
/* .iInterface = DYNAMIC */
};
/* B.4.2 Class-Specific MS Interface Descriptor */
static struct usb_ms_header_descriptor ms_header_desc = {
.bLength = USB_DT_MS_HEADER_SIZE,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubtype = USB_MS_HEADER,
.bcdMSC = cpu_to_le16(0x0100),
/* .wTotalLength = DYNAMIC */
};
/* B.5.1 Standard Bulk OUT Endpoint Descriptor */
static struct usb_endpoint_descriptor bulk_out_desc = {
.bLength = USB_DT_ENDPOINT_AUDIO_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_OUT,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
};
static struct usb_ss_ep_comp_descriptor bulk_out_ss_comp_desc = {
.bLength = sizeof(bulk_out_ss_comp_desc),
.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
/* .bMaxBurst = 0, */
/* .bmAttributes = 0, */
};
/* B.5.2 Class-specific MS Bulk OUT Endpoint Descriptor */
static struct usb_ms_endpoint_descriptor_16 ms_out_desc = {
/* .bLength = DYNAMIC */
.bDescriptorType = USB_DT_CS_ENDPOINT,
.bDescriptorSubtype = USB_MS_GENERAL,
/* .bNumEmbMIDIJack = DYNAMIC */
/* .baAssocJackID = DYNAMIC */
};
/* B.6.1 Standard Bulk IN Endpoint Descriptor */
static struct usb_endpoint_descriptor bulk_in_desc = {
.bLength = USB_DT_ENDPOINT_AUDIO_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
};
static struct usb_ss_ep_comp_descriptor bulk_in_ss_comp_desc = {
.bLength = sizeof(bulk_in_ss_comp_desc),
.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
/* .bMaxBurst = 0, */
/* .bmAttributes = 0, */
};
/* B.6.2 Class-specific MS Bulk IN Endpoint Descriptor */
static struct usb_ms_endpoint_descriptor_16 ms_in_desc = {
/* .bLength = DYNAMIC */
.bDescriptorType = USB_DT_CS_ENDPOINT,
.bDescriptorSubtype = USB_MS_GENERAL,
/* .bNumEmbMIDIJack = DYNAMIC */
/* .baAssocJackID = DYNAMIC */
};
/* string IDs are assigned dynamically */
#define STRING_FUNC_IDX 0
static struct usb_string midi_string_defs[] = {
[STRING_FUNC_IDX].s = "MIDI function",
{ } /* end of list */
};
static struct usb_gadget_strings midi_stringtab = {
.language = 0x0409, /* en-us */
.strings = midi_string_defs,
};
static struct usb_gadget_strings *midi_strings[] = {
&midi_stringtab,
NULL,
};
static inline struct usb_request *midi_alloc_ep_req(struct usb_ep *ep,
unsigned length)
{
return alloc_ep_req(ep, length);
}
static const uint8_t f_midi_cin_length[] = {
0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
};
/*
* Receives a chunk of MIDI data.
*/
static void f_midi_read_data(struct usb_ep *ep, int cable,
uint8_t *data, int length)
{
struct f_midi *midi = ep->driver_data;
struct snd_rawmidi_substream *substream = midi->out_substream[cable];
if (!substream)
/* Nobody is listening - throw it on the floor. */
return;
if (!test_bit(cable, &midi->out_triggered))
return;
snd_rawmidi_receive(substream, data, length);
}
static void f_midi_handle_out_data(struct usb_ep *ep, struct usb_request *req)
{
unsigned int i;
u8 *buf = req->buf;
for (i = 0; i + 3 < req->actual; i += 4)
if (buf[i] != 0) {
int cable = buf[i] >> 4;
int length = f_midi_cin_length[buf[i] & 0x0f];
f_midi_read_data(ep, cable, &buf[i + 1], length);
}
}
static void
f_midi_complete(struct usb_ep *ep, struct usb_request *req)
{
struct f_midi *midi = ep->driver_data;
struct usb_composite_dev *cdev = midi->func.config->cdev;
int status = req->status;
switch (status) {
case 0: /* normal completion */
if (ep == midi->out_ep) {
/* We received stuff. req is queued again, below */
f_midi_handle_out_data(ep, req);
} else if (ep == midi->in_ep) {
/* Our transmit completed. See if there's more to go.
* f_midi_transmit eats req, don't queue it again. */
req->length = 0;
f_midi_transmit(midi);
return;
}
break;
/* this endpoint is normally active while we're configured */
case -ECONNABORTED: /* hardware forced ep reset */
case -ECONNRESET: /* request dequeued */
case -ESHUTDOWN: /* disconnect from host */
VDBG(cdev, "%s gone (%d), %d/%d\n", ep->name, status,
req->actual, req->length);
if (ep == midi->out_ep) {
f_midi_handle_out_data(ep, req);
/* We don't need to free IN requests because it's handled
* by the midi->in_req_fifo. */
free_ep_req(ep, req);
}
return;
case -EOVERFLOW: /* buffer overrun on read means that
* we didn't provide a big enough buffer.
*/
default:
DBG(cdev, "%s complete --> %d, %d/%d\n", ep->name,
status, req->actual, req->length);
break;
case -EREMOTEIO: /* short read */
break;
}
status = usb_ep_queue(ep, req, GFP_ATOMIC);
if (status) {
ERROR(cdev, "kill %s: resubmit %d bytes --> %d\n",
ep->name, req->length, status);
usb_ep_set_halt(ep);
/* FIXME recover later ... somehow */
}
}
static void f_midi_drop_out_substreams(struct f_midi *midi)
{
unsigned int i;
for (i = 0; i < midi->in_ports; i++) {
struct gmidi_in_port *port = midi->in_ports_array + i;
struct snd_rawmidi_substream *substream = port->substream;
if (port->active && substream)
snd_rawmidi_drop_output(substream);
}
}
static int f_midi_start_ep(struct f_midi *midi,
struct usb_function *f,
struct usb_ep *ep)
{
int err;
struct usb_composite_dev *cdev = f->config->cdev;
usb_ep_disable(ep);
err = config_ep_by_speed(midi->gadget, f, ep);
if (err) {
ERROR(cdev, "can't configure %s: %d\n", ep->name, err);
return err;
}
err = usb_ep_enable(ep);
if (err) {
ERROR(cdev, "can't start %s: %d\n", ep->name, err);
return err;
}
ep->driver_data = midi;
return 0;
}
static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
struct f_midi *midi = func_to_midi(f);
unsigned i;
int err;
/* we only set alt for MIDIStreaming interface */
if (intf != midi->ms_id)
return 0;
err = f_midi_start_ep(midi, f, midi->in_ep);
if (err)
return err;
err = f_midi_start_ep(midi, f, midi->out_ep);
if (err)
return err;
/* pre-allocate write usb requests to use on f_midi_transmit. */
while (kfifo_avail(&midi->in_req_fifo)) {
struct usb_request *req =
midi_alloc_ep_req(midi->in_ep, midi->buflen);
if (req == NULL)
return -ENOMEM;
req->length = 0;
req->complete = f_midi_complete;
kfifo_put(&midi->in_req_fifo, req);
}
/* allocate a bunch of read buffers and queue them all at once. */
for (i = 0; i < midi->qlen && err == 0; i++) {
struct usb_request *req =
midi_alloc_ep_req(midi->out_ep, midi->buflen);
if (req == NULL)
return -ENOMEM;
req->complete = f_midi_complete;
err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC);
if (err) {
ERROR(midi, "%s: couldn't enqueue request: %d\n",
midi->out_ep->name, err);
if (req->buf != NULL)
free_ep_req(midi->out_ep, req);
return err;
}
}
return 0;
}
static void f_midi_disable(struct usb_function *f)
{
struct f_midi *midi = func_to_midi(f);
struct usb_composite_dev *cdev = f->config->cdev;
struct usb_request *req = NULL;
DBG(cdev, "disable\n");
/*
* just disable endpoints, forcing completion of pending i/o.
* all our completion handlers free their requests in this case.
*/
usb_ep_disable(midi->in_ep);
usb_ep_disable(midi->out_ep);
/* release IN requests */
while (kfifo_get(&midi->in_req_fifo, &req))
free_ep_req(midi->in_ep, req);
f_midi_drop_out_substreams(midi);
}
static int f_midi_snd_free(struct snd_device *device)
{
return 0;
}
/*
* Converts MIDI commands to USB MIDI packets.
*/
static void f_midi_transmit_byte(struct usb_request *req,
struct gmidi_in_port *port, uint8_t b)
{
uint8_t p[4] = { port->cable << 4, 0, 0, 0 };
uint8_t next_state = STATE_INITIAL;
switch (b) {
case 0xf8 ... 0xff:
/* System Real-Time Messages */
p[0] |= 0x0f;
p[1] = b;
next_state = port->state;
port->state = STATE_REAL_TIME;
break;
case 0xf7:
/* End of SysEx */
switch (port->state) {
case STATE_SYSEX_0:
p[0] |= 0x05;
p[1] = 0xf7;
next_state = STATE_FINISHED;
break;
case STATE_SYSEX_1:
p[0] |= 0x06;
p[1] = port->data[0];
p[2] = 0xf7;
next_state = STATE_FINISHED;
break;
case STATE_SYSEX_2:
p[0] |= 0x07;
p[1] = port->data[0];
p[2] = port->data[1];
p[3] = 0xf7;
next_state = STATE_FINISHED;
break;
default:
/* Ignore byte */
next_state = port->state;
port->state = STATE_INITIAL;
}
break;
case 0xf0 ... 0xf6:
/* System Common Messages */
port->data[0] = port->data[1] = 0;
port->state = STATE_INITIAL;
switch (b) {
case 0xf0:
port->data[0] = b;
port->data[1] = 0;
next_state = STATE_SYSEX_1;
break;
case 0xf1:
case 0xf3:
port->data[0] = b;
next_state = STATE_1PARAM;
break;
case 0xf2:
port->data[0] = b;
next_state = STATE_2PARAM_1;
break;
case 0xf4:
case 0xf5:
next_state = STATE_INITIAL;
break;
case 0xf6:
p[0] |= 0x05;
p[1] = 0xf6;
next_state = STATE_FINISHED;
break;
}
break;
case 0x80 ... 0xef:
/*
* Channel Voice Messages, Channel Mode Messages
* and Control Change Messages.
*/
port->data[0] = b;
port->data[1] = 0;
port->state = STATE_INITIAL;
if (b >= 0xc0 && b <= 0xdf)
next_state = STATE_1PARAM;
else
next_state = STATE_2PARAM_1;
break;
case 0x00 ... 0x7f:
/* Message parameters */
switch (port->state) {
case STATE_1PARAM:
if (port->data[0] < 0xf0)
p[0] |= port->data[0] >> 4;
else
p[0] |= 0x02;
p[1] = port->data[0];
p[2] = b;
/* This is to allow Running State Messages */
next_state = STATE_1PARAM;
break;
case STATE_2PARAM_1:
port->data[1] = b;
next_state = STATE_2PARAM_2;
break;
case STATE_2PARAM_2:
if (port->data[0] < 0xf0)
p[0] |= port->data[0] >> 4;
else
p[0] |= 0x03;
p[1] = port->data[0];
p[2] = port->data[1];
p[3] = b;
/* This is to allow Running State Messages */
next_state = STATE_2PARAM_1;
break;
case STATE_SYSEX_0:
port->data[0] = b;
next_state = STATE_SYSEX_1;
break;
case STATE_SYSEX_1:
port->data[1] = b;
next_state = STATE_SYSEX_2;
break;
case STATE_SYSEX_2:
p[0] |= 0x04;
p[1] = port->data[0];
p[2] = port->data[1];
p[3] = b;
next_state = STATE_SYSEX_0;
break;
}
break;
}
/* States where we have to write into the USB request */
if (next_state == STATE_FINISHED ||
port->state == STATE_SYSEX_2 ||
port->state == STATE_1PARAM ||
port->state == STATE_2PARAM_2 ||
port->state == STATE_REAL_TIME) {
unsigned int length = req->length;
u8 *buf = (u8 *)req->buf + length;
memcpy(buf, p, sizeof(p));
req->length = length + sizeof(p);
if (next_state == STATE_FINISHED) {
next_state = STATE_INITIAL;
port->data[0] = port->data[1] = 0;
}
}
port->state = next_state;
}
static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep)
{
struct usb_request *req = NULL;
unsigned int len, i;
bool active = false;
int err;
/*
* We peek the request in order to reuse it if it fails to enqueue on
* its endpoint
*/
len = kfifo_peek(&midi->in_req_fifo, &req);
if (len != 1) {
ERROR(midi, "%s: Couldn't get usb request\n", __func__);
return -1;
}
/*
* If buffer overrun, then we ignore this transmission.
* IMPORTANT: This will cause the user-space rawmidi device to block
* until a) usb requests have been completed or b) snd_rawmidi_write()
* times out.
*/
if (req->length > 0)
return 0;
for (i = midi->in_last_port; i < midi->in_ports; ++i) {
struct gmidi_in_port *port = midi->in_ports_array + i;
struct snd_rawmidi_substream *substream = port->substream;
if (!port->active || !substream)
continue;
while (req->length + 3 < midi->buflen) {
uint8_t b;
if (snd_rawmidi_transmit(substream, &b, 1) != 1) {
port->active = 0;
break;
}
f_midi_transmit_byte(req, port, b);
}
active = !!port->active;
if (active)
break;
}
midi->in_last_port = active ? i : 0;
if (req->length <= 0)
goto done;
err = usb_ep_queue(ep, req, GFP_ATOMIC);
if (err < 0) {
ERROR(midi, "%s failed to queue req: %d\n",
midi->in_ep->name, err);
req->length = 0; /* Re-use request next time. */
} else {
/* Upon success, put request at the back of the queue. */
kfifo_skip(&midi->in_req_fifo);
kfifo_put(&midi->in_req_fifo, req);
}
done:
return active;
}
static void f_midi_transmit(struct f_midi *midi)
{
struct usb_ep *ep = midi->in_ep;
int ret;
unsigned long flags;
/* We only care about USB requests if IN endpoint is enabled */
if (!ep || !ep->enabled)
goto drop_out;
spin_lock_irqsave(&midi->transmit_lock, flags);
do {
ret = f_midi_do_transmit(midi, ep);
if (ret < 0) {
spin_unlock_irqrestore(&midi->transmit_lock, flags);
goto drop_out;
}
} while (ret);
spin_unlock_irqrestore(&midi->transmit_lock, flags);
return;
drop_out:
f_midi_drop_out_substreams(midi);
}
static void f_midi_in_work(struct work_struct *work)
{
struct f_midi *midi;
midi = container_of(work, struct f_midi, work);
f_midi_transmit(midi);
}
static int f_midi_in_open(struct snd_rawmidi_substream *substream)
{
struct f_midi *midi = substream->rmidi->private_data;
struct gmidi_in_port *port;
if (substream->number >= midi->in_ports)
return -EINVAL;
VDBG(midi, "%s()\n", __func__);
port = midi->in_ports_array + substream->number;
port->substream = substream;
port->state = STATE_INITIAL;
return 0;
}
static int f_midi_in_close(struct snd_rawmidi_substream *substream)
{
struct f_midi *midi = substream->rmidi->private_data;
VDBG(midi, "%s()\n", __func__);
return 0;
}
static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up)
{
struct f_midi *midi = substream->rmidi->private_data;
if (substream->number >= midi->in_ports)
return;
VDBG(midi, "%s() %d\n", __func__, up);
midi->in_ports_array[substream->number].active = up;
if (up)
queue_work(system_highpri_wq, &midi->work);
}
static int f_midi_out_open(struct snd_rawmidi_substream *substream)
{
struct f_midi *midi = substream->rmidi->private_data;
if (substream->number >= MAX_PORTS)
return -EINVAL;
VDBG(midi, "%s()\n", __func__);
midi->out_substream[substream->number] = substream;
return 0;
}
static int f_midi_out_close(struct snd_rawmidi_substream *substream)
{
struct f_midi *midi = substream->rmidi->private_data;
VDBG(midi, "%s()\n", __func__);
return 0;
}
static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up)
{
struct f_midi *midi = substream->rmidi->private_data;
VDBG(midi, "%s()\n", __func__);
if (up)
set_bit(substream->number, &midi->out_triggered);
else
clear_bit(substream->number, &midi->out_triggered);
}
static const struct snd_rawmidi_ops gmidi_in_ops = {
.open = f_midi_in_open,
.close = f_midi_in_close,
.trigger = f_midi_in_trigger,
};
static const struct snd_rawmidi_ops gmidi_out_ops = {
.open = f_midi_out_open,
.close = f_midi_out_close,
.trigger = f_midi_out_trigger
};
static inline void f_midi_unregister_card(struct f_midi *midi)
{
if (midi->card) {
snd_card_free(midi->card);
midi->card = NULL;
}
}
/* register as a sound "card" */
static int f_midi_register_card(struct f_midi *midi)
{
struct snd_card *card;
struct snd_rawmidi *rmidi;
int err;
static struct snd_device_ops ops = {
.dev_free = f_midi_snd_free,
};
err = snd_card_new(&midi->gadget->dev, midi->index, midi->id,
THIS_MODULE, 0, &card);
if (err < 0) {
ERROR(midi, "snd_card_new() failed\n");
goto fail;
}
midi->card = card;
err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, midi, &ops);
if (err < 0) {
ERROR(midi, "snd_device_new() failed: error %d\n", err);
goto fail;
}
strcpy(card->driver, f_midi_longname);
strcpy(card->longname, f_midi_longname);
strcpy(card->shortname, f_midi_shortname);
/* Set up rawmidi */
snd_component_add(card, "MIDI");
err = snd_rawmidi_new(card, card->longname, 0,
midi->out_ports, midi->in_ports, &rmidi);
if (err < 0) {
ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err);
goto fail;
}
midi->rmidi = rmidi;
midi->in_last_port = 0;
strcpy(rmidi->name, card->shortname);
rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
SNDRV_RAWMIDI_INFO_INPUT |
SNDRV_RAWMIDI_INFO_DUPLEX;
rmidi->private_data = midi;
rmidi->private_free = f_midi_rmidi_free;
midi->free_ref++;
/*
* Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
* It's an upside-down world being a gadget.
*/
snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops);
snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops);
/* register it - we're ready to go */
err = snd_card_register(card);
if (err < 0) {
ERROR(midi, "snd_card_register() failed\n");
goto fail;
}
VDBG(midi, "%s() finished ok\n", __func__);
return 0;
fail:
f_midi_unregister_card(midi);
return err;
}
/* MIDI function driver setup/binding */
static int f_midi_bind(struct usb_configuration *c, struct usb_function *f)
{
struct usb_descriptor_header **midi_function;
struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS];
struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS];
struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS];
struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS];
struct usb_composite_dev *cdev = c->cdev;
struct f_midi *midi = func_to_midi(f);
struct usb_string *us;
int status, n, jack = 1, i = 0, endpoint_descriptor_index = 0;
midi->gadget = cdev->gadget;
INIT_WORK(&midi->work, f_midi_in_work);
status = f_midi_register_card(midi);
if (status < 0)
goto fail_register;
/* maybe allocate device-global string ID */
us = usb_gstrings_attach(c->cdev, midi_strings,
ARRAY_SIZE(midi_string_defs));
if (IS_ERR(us)) {
status = PTR_ERR(us);
goto fail;
}
ac_interface_desc.iInterface = us[STRING_FUNC_IDX].id;
/* We have two interfaces, AudioControl and MIDIStreaming */
status = usb_interface_id(c, f);
if (status < 0)
goto fail;
ac_interface_desc.bInterfaceNumber = status;
status = usb_interface_id(c, f);
if (status < 0)
goto fail;
ms_interface_desc.bInterfaceNumber = status;
ac_header_desc.baInterfaceNr[0] = status;
midi->ms_id = status;
status = -ENODEV;
/* allocate instance-specific endpoints */
midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
if (!midi->in_ep)
goto fail;
midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc);
if (!midi->out_ep)
goto fail;
/* allocate temporary function list */
midi_function = kcalloc((MAX_PORTS * 4) + 11, sizeof(*midi_function),
GFP_KERNEL);
if (!midi_function) {
status = -ENOMEM;
goto fail;
}
/*
* construct the function's descriptor set. As the number of
* input and output MIDI ports is configurable, we have to do
* it that way.
*/
/* add the headers - these are always the same */
midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc;
midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc;
midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc;
/* calculate the header's wTotalLength */
n = USB_DT_MS_HEADER_SIZE
+ (midi->in_ports + midi->out_ports) *
(USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1));
ms_header_desc.wTotalLength = cpu_to_le16(n);
midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc;
/* configure the external IN jacks, each linked to an embedded OUT jack */
for (n = 0; n < midi->in_ports; n++) {
struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n];
struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n];
in_ext->bLength = USB_DT_MIDI_IN_SIZE;
in_ext->bDescriptorType = USB_DT_CS_INTERFACE;
in_ext->bDescriptorSubtype = USB_MS_MIDI_IN_JACK;
in_ext->bJackType = USB_MS_EXTERNAL;
in_ext->bJackID = jack++;
in_ext->iJack = 0;
midi_function[i++] = (struct usb_descriptor_header *) in_ext;
out_emb->bLength = USB_DT_MIDI_OUT_SIZE(1);
out_emb->bDescriptorType = USB_DT_CS_INTERFACE;
out_emb->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK;
out_emb->bJackType = USB_MS_EMBEDDED;
out_emb->bJackID = jack++;
out_emb->bNrInputPins = 1;
out_emb->pins[0].baSourcePin = 1;
out_emb->pins[0].baSourceID = in_ext->bJackID;
out_emb->iJack = 0;
midi_function[i++] = (struct usb_descriptor_header *) out_emb;
/* link it to the endpoint */
ms_in_desc.baAssocJackID[n] = out_emb->bJackID;
}
/* configure the external OUT jacks, each linked to an embedded IN jack */
for (n = 0; n < midi->out_ports; n++) {
struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n];
struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n];
in_emb->bLength = USB_DT_MIDI_IN_SIZE;
in_emb->bDescriptorType = USB_DT_CS_INTERFACE;
in_emb->bDescriptorSubtype = USB_MS_MIDI_IN_JACK;
in_emb->bJackType = USB_MS_EMBEDDED;
in_emb->bJackID = jack++;
in_emb->iJack = 0;
midi_function[i++] = (struct usb_descriptor_header *) in_emb;
out_ext->bLength = USB_DT_MIDI_OUT_SIZE(1);
out_ext->bDescriptorType = USB_DT_CS_INTERFACE;
out_ext->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK;
out_ext->bJackType = USB_MS_EXTERNAL;
out_ext->bJackID = jack++;
out_ext->bNrInputPins = 1;
out_ext->iJack = 0;
out_ext->pins[0].baSourceID = in_emb->bJackID;
out_ext->pins[0].baSourcePin = 1;
midi_function[i++] = (struct usb_descriptor_header *) out_ext;
/* link it to the endpoint */
ms_out_desc.baAssocJackID[n] = in_emb->bJackID;
}
/* configure the endpoint descriptors ... */
ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports);
ms_out_desc.bNumEmbMIDIJack = midi->in_ports;
ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports);
ms_in_desc.bNumEmbMIDIJack = midi->out_ports;
/* ... and add them to the list */
endpoint_descriptor_index = i;
midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc;
midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc;
midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc;
midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc;
midi_function[i++] = NULL;
/*
* support all relevant hardware speeds... we expect that when
* hardware is dual speed, all bulk-capable endpoints work at
* both speeds
*/
/* copy descriptors, and track endpoint copies */
f->fs_descriptors = usb_copy_descriptors(midi_function);
if (!f->fs_descriptors)
goto fail_f_midi;
bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
f->hs_descriptors = usb_copy_descriptors(midi_function);
if (!f->hs_descriptors)
goto fail_f_midi;
bulk_in_desc.wMaxPacketSize = cpu_to_le16(1024);
bulk_out_desc.wMaxPacketSize = cpu_to_le16(1024);
i = endpoint_descriptor_index;
midi_function[i++] = (struct usb_descriptor_header *)
&bulk_out_desc;
midi_function[i++] = (struct usb_descriptor_header *)
&bulk_out_ss_comp_desc;
midi_function[i++] = (struct usb_descriptor_header *)
&ms_out_desc;
midi_function[i++] = (struct usb_descriptor_header *)
&bulk_in_desc;
midi_function[i++] = (struct usb_descriptor_header *)
&bulk_in_ss_comp_desc;
midi_function[i++] = (struct usb_descriptor_header *)
&ms_in_desc;
f->ss_descriptors = usb_copy_descriptors(midi_function);
if (!f->ss_descriptors)
goto fail_f_midi;
kfree(midi_function);
return 0;
fail_f_midi:
kfree(midi_function);
usb_free_all_descriptors(f);
fail:
f_midi_unregister_card(midi);
fail_register:
ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
return status;
}
static inline struct f_midi_opts *to_f_midi_opts(struct config_item *item)
{
return container_of(to_config_group(item), struct f_midi_opts,
func_inst.group);
}
static void midi_attr_release(struct config_item *item)
{
struct f_midi_opts *opts = to_f_midi_opts(item);
usb_put_function_instance(&opts->func_inst);
}
static struct configfs_item_operations midi_item_ops = {
.release = midi_attr_release,
};
#define F_MIDI_OPT(name, test_limit, limit) \
static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \
{ \
struct f_midi_opts *opts = to_f_midi_opts(item); \
int result; \
\
mutex_lock(&opts->lock); \
result = sprintf(page, "%u\n", opts->name); \
mutex_unlock(&opts->lock); \
\
return result; \
} \
\
static ssize_t f_midi_opts_##name##_store(struct config_item *item, \
const char *page, size_t len) \
{ \
struct f_midi_opts *opts = to_f_midi_opts(item); \
int ret; \
u32 num; \
\
mutex_lock(&opts->lock); \
if (opts->refcnt > 1) { \
ret = -EBUSY; \
goto end; \
} \
\
ret = kstrtou32(page, 0, &num); \
if (ret) \
goto end; \
\
if (test_limit && num > limit) { \
ret = -EINVAL; \
goto end; \
} \
opts->name = num; \
ret = len; \
\
end: \
mutex_unlock(&opts->lock); \
return ret; \
} \
\
CONFIGFS_ATTR(f_midi_opts_, name);
#define F_MIDI_OPT_SIGNED(name, test_limit, limit) \
static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \
{ \
struct f_midi_opts *opts = to_f_midi_opts(item); \
int result; \
\
mutex_lock(&opts->lock); \
result = sprintf(page, "%d\n", opts->name); \
mutex_unlock(&opts->lock); \
\
return result; \
} \
\
static ssize_t f_midi_opts_##name##_store(struct config_item *item, \
const char *page, size_t len) \
{ \
struct f_midi_opts *opts = to_f_midi_opts(item); \
int ret; \
s32 num; \
\
mutex_lock(&opts->lock); \
if (opts->refcnt > 1) { \
ret = -EBUSY; \
goto end; \
} \
\
ret = kstrtos32(page, 0, &num); \
if (ret) \
goto end; \
\
if (test_limit && num > limit) { \
ret = -EINVAL; \
goto end; \
} \
opts->name = num; \
ret = len; \
\
end: \
mutex_unlock(&opts->lock); \
return ret; \
} \
\
CONFIGFS_ATTR(f_midi_opts_, name);
F_MIDI_OPT_SIGNED(index, true, SNDRV_CARDS);
F_MIDI_OPT(buflen, false, 0);
F_MIDI_OPT(qlen, false, 0);
F_MIDI_OPT(in_ports, true, MAX_PORTS);
F_MIDI_OPT(out_ports, true, MAX_PORTS);
static ssize_t f_midi_opts_id_show(struct config_item *item, char *page)
{
struct f_midi_opts *opts = to_f_midi_opts(item);
ssize_t result;
mutex_lock(&opts->lock);
if (opts->id) {
result = strscpy(page, opts->id, PAGE_SIZE);
} else {
page[0] = 0;
result = 0;
}
mutex_unlock(&opts->lock);
return result;
}
static ssize_t f_midi_opts_id_store(struct config_item *item,
const char *page, size_t len)
{
struct f_midi_opts *opts = to_f_midi_opts(item);
int ret;
char *c;
mutex_lock(&opts->lock);
if (opts->refcnt > 1) {
ret = -EBUSY;
goto end;
}
c = kstrndup(page, len, GFP_KERNEL);
if (!c) {
ret = -ENOMEM;
goto end;
}
if (opts->id_allocated)
kfree(opts->id);
opts->id = c;
opts->id_allocated = true;
ret = len;
end:
mutex_unlock(&opts->lock);
return ret;
}
CONFIGFS_ATTR(f_midi_opts_, id);
static struct configfs_attribute *midi_attrs[] = {
&f_midi_opts_attr_index,
&f_midi_opts_attr_buflen,
&f_midi_opts_attr_qlen,
&f_midi_opts_attr_in_ports,
&f_midi_opts_attr_out_ports,
&f_midi_opts_attr_id,
NULL,
};
static const struct config_item_type midi_func_type = {
.ct_item_ops = &midi_item_ops,
.ct_attrs = midi_attrs,
.ct_owner = THIS_MODULE,
};
static void f_midi_free_inst(struct usb_function_instance *f)
{
struct f_midi_opts *opts;
bool free = false;
opts = container_of(f, struct f_midi_opts, func_inst);
mutex_lock(&opts->lock);
if (!--opts->refcnt) {
free = true;
}
mutex_unlock(&opts->lock);
if (free) {
if (opts->id_allocated)
kfree(opts->id);
kfree(opts);
}
}
static struct usb_function_instance *f_midi_alloc_inst(void)
{
struct f_midi_opts *opts;
opts = kzalloc(sizeof(*opts), GFP_KERNEL);
if (!opts)
return ERR_PTR(-ENOMEM);
mutex_init(&opts->lock);
opts->func_inst.free_func_inst = f_midi_free_inst;
opts->index = SNDRV_DEFAULT_IDX1;
opts->id = SNDRV_DEFAULT_STR1;
opts->buflen = 512;
opts->qlen = 32;
opts->in_ports = 1;
opts->out_ports = 1;
opts->refcnt = 1;
config_group_init_type_name(&opts->func_inst.group, "",
&midi_func_type);
return &opts->func_inst;
}
static void f_midi_free(struct usb_function *f)
{
struct f_midi *midi;
struct f_midi_opts *opts;
bool free = false;
midi = func_to_midi(f);
opts = container_of(f->fi, struct f_midi_opts, func_inst);
mutex_lock(&opts->lock);
if (!--midi->free_ref) {
kfree(midi->id);
kfifo_free(&midi->in_req_fifo);
kfree(midi);
free = true;
}
mutex_unlock(&opts->lock);
if (free)
f_midi_free_inst(&opts->func_inst);
}
static void f_midi_rmidi_free(struct snd_rawmidi *rmidi)
{
f_midi_free(rmidi->private_data);
}
static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
{
struct usb_composite_dev *cdev = f->config->cdev;
struct f_midi *midi = func_to_midi(f);
struct snd_card *card;
DBG(cdev, "unbind\n");
/* just to be sure */
f_midi_disable(f);
card = midi->card;
midi->card = NULL;
if (card)
snd_card_free_when_closed(card);
usb_free_all_descriptors(f);
}
static struct usb_function *f_midi_alloc(struct usb_function_instance *fi)
{
struct f_midi *midi = NULL;
struct f_midi_opts *opts;
int status, i;
opts = container_of(fi, struct f_midi_opts, func_inst);
mutex_lock(&opts->lock);
/* sanity check */
if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) {
status = -EINVAL;
goto setup_fail;
}
/* allocate and initialize one new instance */
midi = kzalloc(struct_size(midi, in_ports_array, opts->in_ports),
GFP_KERNEL);
if (!midi) {
status = -ENOMEM;
goto setup_fail;
}
midi->in_ports = opts->in_ports;
for (i = 0; i < opts->in_ports; i++)
midi->in_ports_array[i].cable = i;
/* set up ALSA midi devices */
midi->id = kstrdup(opts->id, GFP_KERNEL);
if (opts->id && !midi->id) {
status = -ENOMEM;
goto midi_free;
}
midi->out_ports = opts->out_ports;
midi->index = opts->index;
midi->buflen = opts->buflen;
midi->qlen = opts->qlen;
midi->in_last_port = 0;
midi->free_ref = 1;
status = kfifo_alloc(&midi->in_req_fifo, midi->qlen, GFP_KERNEL);
if (status)
goto midi_free;
spin_lock_init(&midi->transmit_lock);
++opts->refcnt;
mutex_unlock(&opts->lock);
midi->func.name = "gmidi function";
midi->func.bind = f_midi_bind;
midi->func.unbind = f_midi_unbind;
midi->func.set_alt = f_midi_set_alt;
midi->func.disable = f_midi_disable;
midi->func.free_func = f_midi_free;
return &midi->func;
midi_free:
if (midi)
kfree(midi->id);
kfree(midi);
setup_fail:
mutex_unlock(&opts->lock);
return ERR_PTR(status);
}
DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc);
Codebase Browser
linux