[alsa-devel] [PATCH v2] MIDI driver for Behringer BCD2000 USB device
Mario Kicherer
dev at kicherer.org
Wed Feb 5 21:10:59 CET 2014
This patch adds initial support for the Behringer BCD2000 USB DJ controller.
At the moment, only the MIDI part of the device is working, i.e. knobs,
buttons and LEDs.
I also plan to add support for the audio part, but I assume that this will
require more effort than the rather simple MIDI interface. Progress can be
tracked at https://github.com/anyc/snd-usb-bcd2000.
Changes since v1:
- fixed the various code style issues, thanks to Daniel Mack and
checkpatch.pl.
Signed-off-by: Mario Kicherer <dev at kicherer.org>
---
sound/usb/Kconfig | 14 ++
sound/usb/Makefile | 2 +-
sound/usb/bcd2000/Makefile | 3 +
sound/usb/bcd2000/bcd2000.c | 553 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 571 insertions(+), 1 deletion(-)
create mode 100644 sound/usb/bcd2000/Makefile
create mode 100644 sound/usb/bcd2000/bcd2000.c
diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
index de9408b..2abafea 100644
--- a/sound/usb/Kconfig
+++ b/sound/usb/Kconfig
@@ -146,5 +146,19 @@ config SND_USB_HIFACE
To compile this driver as a module, choose M here: the module
will be called snd-usb-hiface.
+config SND_USB_BCD2000
+ tristate "Behringer BCD2000 MIDI driver"
+ select SND_HWDEP
+ select SND_RAWMIDI
+ help
+ Say Y here to include MIDI support for the Behringer BCD2000 DJ
+ controller.
+
+ Audio support is still work-in-progress at
+ https://github.com/anyc/snd-usb-bcd2000
+
+ To compile this driver as a module, choose M here: the module
+ will be called snd-usb-bcd2000.
+
endif # SND_USB
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index abe668f..2b92f0d 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -23,4 +23,4 @@ obj-$(CONFIG_SND_USB_UA101) += snd-usbmidi-lib.o
obj-$(CONFIG_SND_USB_USX2Y) += snd-usbmidi-lib.o
obj-$(CONFIG_SND_USB_US122L) += snd-usbmidi-lib.o
-obj-$(CONFIG_SND) += misc/ usx2y/ caiaq/ 6fire/ hiface/
+obj-$(CONFIG_SND) += misc/ usx2y/ caiaq/ 6fire/ hiface/ bcd2000/
diff --git a/sound/usb/bcd2000/Makefile b/sound/usb/bcd2000/Makefile
new file mode 100644
index 0000000..6540136
--- /dev/null
+++ b/sound/usb/bcd2000/Makefile
@@ -0,0 +1,3 @@
+snd-usb-bcd2000-y := bcd2000.o
+
+obj-$(CONFIG_SND_USB_BCD2000) += snd-usb-bcd2000.o
\ No newline at end of file
diff --git a/sound/usb/bcd2000/bcd2000.c b/sound/usb/bcd2000/bcd2000.c
new file mode 100644
index 0000000..d8c5525
--- /dev/null
+++ b/sound/usb/bcd2000/bcd2000.c
@@ -0,0 +1,553 @@
+/*
+ * Behringer BCD2000 driver
+ *
+ * Copyright (C) 2014 Mario Kicherer (dev at kicherer.org)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/rawmidi.h>
+#include "../usbaudio.h"
+#include "../midi.h"
+
+#define DEVICE_NAME "Behringer BCD2000"
+#define DEVICE_SHORTNAME "bcd2000"
+
+#define PREFIX DEVICE_SHORTNAME ": "
+#define BUFSIZE 64
+
+static struct usb_device_id id_table[] = {
+ { USB_DEVICE(0x1397, 0x00bd) },
+ { },
+};
+
+static int debug;
+module_param(debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "enable debug output (default: 0)");
+
+static unsigned char device_cmd_prefix[] = {0x03, 0x00};
+
+static unsigned char bcd2000_init_sequence[] = {
+ 0x07, 0x00, 0x00, 0x00, 0x78, 0x48, 0x1c, 0x81,
+ 0xc4, 0x00, 0x00, 0x00, 0x5e, 0x53, 0x4a, 0xf7,
+ 0x18, 0xfa, 0x11, 0xff, 0x6c, 0xf3, 0x90, 0xff,
+ 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+ 0x18, 0xfa, 0x11, 0xff, 0x14, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0xf2, 0x34, 0x4a, 0xf7,
+ 0x18, 0xfa, 0x11, 0xff};
+
+struct bcd2000 {
+ struct usb_device *dev;
+ struct snd_card *card;
+ struct usb_interface *intf;
+ int card_index;
+ struct snd_pcm *pcm;
+ struct list_head midi_list;
+ spinlock_t lock;
+ struct mutex mutex;
+
+ int midi_out_active;
+ struct snd_rawmidi *rmidi;
+ struct snd_rawmidi_substream *midi_receive_substream;
+ struct snd_rawmidi_substream *midi_out_substream;
+
+ unsigned char midi_in_buf[BUFSIZE];
+ unsigned char midi_out_buf[BUFSIZE];
+
+ unsigned char midi_cmd_buf[3];
+ unsigned char midi_cmd_offset;
+
+ struct urb *midi_out_urb;
+ struct urb *midi_in_urb;
+};
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
+static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;
+
+static DEFINE_MUTEX(devices_mutex);
+static unsigned int devices_used;
+static struct usb_driver bcd2000_driver;
+
+
+
+
+
+
+static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
+{
+ return 0;
+}
+
+static int bcd2000_midi_input_close(struct snd_rawmidi_substream *substream)
+{
+ return 0;
+}
+
+static void bcd2000_midi_input_trigger(struct snd_rawmidi_substream *substream,
+ int up)
+{
+ struct bcd2000 *bcd2k = substream->rmidi->private_data;
+
+ if (!bcd2k)
+ return;
+
+ bcd2k->midi_receive_substream = up ? substream : NULL;
+}
+
+static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k,
+ const unsigned char *buf, int len)
+{
+ unsigned char length, cmd, buf_offset, tocopy;
+
+ if (!bcd2k->midi_receive_substream)
+ return;
+
+ if (debug) {
+ print_hex_dump(KERN_DEBUG, "received from device: ",
+ DUMP_PREFIX_NONE, 16, 1, buf, len, false);
+ }
+
+ if (len < 2)
+ return;
+
+ /*
+ * The BCD2000 sends MIDI commands with 2 or 3 bytes length. In case of
+ * 2 bytes, the command is the same as before.
+ *
+ * Packet structure: mm nn oo (pp)
+ * mm: payload length
+ * nn: MIDI command or note
+ * oo: note or velocity
+ * pp: velocity
+ */
+
+ length = buf[0];
+
+ /* ignore packets without payload */
+ if (length == 0)
+ return;
+
+ /*
+ * The MIDI packets the BCD2000 sends can be arbitrarily truncated or
+ * concatenated. Therefore, this loop accumulates the bytes from the
+ * input buffer until a full valid MIDI packet is in the MIDI command
+ * buffer "midi_cmd_buf".
+ */
+
+ buf_offset = 1;
+ while (buf_offset <= length) {
+ cmd = buf[buf_offset];
+
+ if (bcd2k->midi_cmd_offset == 0 && cmd != 0x90 && cmd != 0xb0) {
+ /*
+ * this is a 2-byte midi packet -> reuse command byte
+ * from last midi packet
+ */
+ bcd2k->midi_cmd_offset = 1;
+ }
+
+ /* determine the number of bytes we want to copy this time */
+ tocopy = min(3 - bcd2k->midi_cmd_offset,
+ length - (buf_offset - 1));
+
+ /* safety check */
+ if (bcd2k->midi_cmd_offset + tocopy < BUFSIZE &&
+ buf_offset + tocopy < len) {
+ memcpy(&bcd2k->midi_cmd_buf[bcd2k->midi_cmd_offset],
+ &buf[buf_offset], tocopy);
+ } else {
+ snd_printk(KERN_ERR PREFIX "access violation in %s\n",
+ __func__);
+ }
+
+ bcd2k->midi_cmd_offset += tocopy;
+ buf_offset += tocopy;
+
+ /* is our MIDI packet complete? */
+ if (bcd2k->midi_cmd_offset == 3) {
+ if (debug) {
+ print_hex_dump(KERN_DEBUG,
+ "sending to userspace: ",
+ DUMP_PREFIX_NONE, 16, 1,
+ bcd2k->midi_cmd_buf,
+ bcd2k->midi_cmd_offset, false);
+ }
+
+ /* send MIDI packet */
+ snd_rawmidi_receive(bcd2k->midi_receive_substream,
+ bcd2k->midi_cmd_buf, 3);
+
+ bcd2k->midi_cmd_offset = 0;
+ }
+ }
+}
+
+static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
+{
+ return 0;
+}
+
+static int bcd2000_midi_output_close(struct snd_rawmidi_substream *substream)
+{
+ struct bcd2000 *bcd2k = substream->rmidi->private_data;
+ if (bcd2k->midi_out_active) {
+ usb_free_urb(bcd2k->midi_out_urb);
+ bcd2k->midi_out_active = 0;
+ }
+ return 0;
+}
+
+static void bcd2000_midi_send(struct bcd2000 *bcd2k,
+ struct snd_rawmidi_substream *substream)
+{
+ int len, ret;
+
+ BUILD_BUG_ON(sizeof(device_cmd_prefix) >= BUFSIZE);
+ /* copy the "set LED" command bytes */
+ memcpy(bcd2k->midi_out_buf, device_cmd_prefix,
+ sizeof(device_cmd_prefix));
+
+ /*
+ * get MIDI packet and leave space for command prefix
+ * and payload length
+ */
+ len = snd_rawmidi_transmit(substream,
+ bcd2k->midi_out_buf + 3, BUFSIZE - 3);
+
+ if (len <= 0)
+ return;
+
+ /* set payload length */
+ bcd2k->midi_out_buf[2] = len;
+ bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
+
+ if (debug) {
+ print_hex_dump(KERN_DEBUG, "sending to device: ",
+ DUMP_PREFIX_NONE, 16, 1,
+ bcd2k->midi_out_buf, len+3, false);
+ }
+
+ /* send packet to the BCD2000 */
+ ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
+ if (ret < 0) {
+ dev_err(&bcd2k->dev->dev, PREFIX
+ "%s (%p): usb_submit_urb() failed"
+ "ret=%d, len=%d\n", __func__, substream, ret, len);
+ } else {
+ bcd2k->midi_out_active = 1;
+ }
+}
+
+static void bcd2000_midi_output_done(struct urb *urb)
+{
+ struct bcd2000 *bcd2k = urb->context;
+
+ bcd2k->midi_out_active = 0;
+ if (urb->status != 0) {
+ dev_err(&urb->dev->dev, PREFIX "urb status: %d\n", urb->status);
+ return;
+ }
+
+ if (!bcd2k->midi_out_substream)
+ return;
+
+ bcd2000_midi_send(bcd2k, bcd2k->midi_out_substream);
+}
+
+static void bcd2000_command_reply_dispatch(struct urb *urb)
+{
+ int ret;
+ struct device *dev = &urb->dev->dev;
+ struct bcd2000 *bcd2k = urb->context;
+
+ if (urb->status || !bcd2k) {
+ dev_warn(dev, "received urb->status = %i\n", urb->status);
+ return;
+ }
+
+ if (urb->actual_length > 0)
+ bcd2000_midi_handle_input(bcd2k, urb->transfer_buffer,
+ urb->actual_length);
+
+ bcd2k->midi_in_urb->actual_length = 0;
+ ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
+ if (ret < 0)
+ dev_err(dev, "unable to submit urb. OOM!?\n");
+}
+
+static void bcd2000_midi_output_trigger(struct snd_rawmidi_substream *substream,
+ int up)
+{
+ struct bcd2000 *bcd2k = substream->rmidi->private_data;
+
+ if (up) {
+ bcd2k->midi_out_substream = substream;
+ if (!bcd2k->midi_out_active)
+ bcd2000_midi_send(bcd2k, substream);
+ } else {
+ bcd2k->midi_out_substream = NULL;
+ }
+}
+
+static struct snd_rawmidi_ops bcd2000_midi_output = {
+ .open = bcd2000_midi_output_open,
+ .close = bcd2000_midi_output_close,
+ .trigger = bcd2000_midi_output_trigger,
+};
+
+static struct snd_rawmidi_ops bcd2000_midi_input = {
+ .open = bcd2000_midi_input_open,
+ .close = bcd2000_midi_input_close,
+ .trigger = bcd2000_midi_input_trigger,
+};
+
+static void bcd2000_init_device(struct bcd2000 *bcd2k)
+{
+ int ret;
+
+ /* copy init sequence into buffer */
+ memcpy(bcd2k->midi_out_buf, bcd2000_init_sequence, 52);
+ bcd2k->midi_out_urb->transfer_buffer_length = 52;
+
+ /* submit sequence */
+ ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
+ if (ret < 0) {
+ dev_err(&bcd2k->dev->dev, PREFIX
+ "%s: usb_submit_urb() failed,"
+ "ret=%d: ", __func__, ret);
+ } else {
+ bcd2k->midi_out_active = 1;
+ }
+
+ /* send empty packet to enable button and controller events */
+ bcd2k->midi_in_urb->actual_length = 0;
+ ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
+}
+
+static void bcd2000_init_midi(struct bcd2000 *bcd2k)
+{
+ int ret;
+ struct snd_rawmidi *rmidi;
+
+ ret = snd_rawmidi_new(bcd2k->card, bcd2k->card->shortname, 0,
+ 1, /* output */
+ 1, /* input */
+ &rmidi);
+
+ if (ret < 0)
+ return;
+
+ strlcpy(rmidi->name, bcd2k->card->shortname, sizeof(rmidi->name));
+
+ rmidi->info_flags = SNDRV_RAWMIDI_INFO_DUPLEX;
+ rmidi->private_data = bcd2k;
+
+ rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
+ snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
+ &bcd2000_midi_output);
+
+ rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
+ snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
+ &bcd2000_midi_input);
+
+ bcd2k->rmidi = rmidi;
+
+ bcd2k->midi_in_urb = usb_alloc_urb(0, GFP_KERNEL);
+ bcd2k->midi_out_urb = usb_alloc_urb(0, GFP_KERNEL);
+
+ usb_fill_int_urb(bcd2k->midi_in_urb, bcd2k->dev,
+ usb_rcvbulkpipe(bcd2k->dev, 0x81),
+ bcd2k->midi_in_buf, BUFSIZE,
+ bcd2000_command_reply_dispatch, bcd2k, 1);
+
+ usb_fill_int_urb(bcd2k->midi_out_urb, bcd2k->dev,
+ usb_sndbulkpipe(bcd2k->dev, 0x1),
+ bcd2k->midi_out_buf, BUFSIZE,
+ bcd2000_midi_output_done, bcd2k, 1);
+
+ bcd2000_init_device(bcd2k);
+}
+
+static void bcd2000_close_midi(struct bcd2000 *bcd2k)
+{
+ usb_free_urb(bcd2k->midi_out_urb);
+ usb_free_urb(bcd2k->midi_in_urb);
+}
+
+
+
+
+
+/*
+ * general part
+ */
+
+static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
+ struct usb_interface *interface)
+{
+ struct usb_interface *intf;
+
+ mutex_lock(&bcd2k->mutex);
+ intf = bcd2k->intf;
+ bcd2k->intf = NULL;
+ mutex_unlock(&bcd2k->mutex);
+ if (intf) {
+ usb_set_intfdata(intf, NULL);
+ if (intf != interface)
+ usb_driver_release_interface(&bcd2000_driver,
+ intf);
+ }
+}
+
+static void bcd2000_card_free(struct snd_card *card)
+{
+ /* empty for now */
+}
+
+static int bcd2000_probe(struct usb_interface *interface,
+ const struct usb_device_id *usb_id)
+{
+ struct snd_card *card;
+ struct bcd2000 *bcd2k;
+ unsigned int card_index;
+ char usb_path[32];
+ int err;
+
+
+ mutex_lock(&devices_mutex);
+
+ for (card_index = 0; card_index < SNDRV_CARDS; ++card_index)
+ if (enable[card_index] && !(devices_used & (1 << card_index)))
+ break;
+ if (card_index >= SNDRV_CARDS) {
+ mutex_unlock(&devices_mutex);
+ return -ENOENT;
+ }
+ err = snd_card_create(index[card_index], id[card_index], THIS_MODULE,
+ sizeof(*bcd2k), &card);
+ if (err < 0) {
+ mutex_unlock(&devices_mutex);
+ return err;
+ }
+ card->private_free = bcd2000_card_free;
+ bcd2k = card->private_data;
+ bcd2k->dev = interface_to_usbdev(interface);
+ bcd2k->card = card;
+ bcd2k->card_index = card_index;
+ INIT_LIST_HEAD(&bcd2k->midi_list);
+ spin_lock_init(&bcd2k->lock);
+ mutex_init(&bcd2k->mutex);
+
+ bcd2k->intf = interface;
+
+ snd_card_set_dev(card, &interface->dev);
+
+ strcpy(card->driver, DEVICE_NAME);
+ strcpy(card->shortname, DEVICE_SHORTNAME);
+ usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
+ snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),
+ DEVICE_NAME ", at %s, %s speed",
+ usb_path,
+ bcd2k->dev->speed == USB_SPEED_HIGH ? "high" : "full");
+
+ dev_info(&bcd2k->dev->dev, PREFIX "%s", bcd2k->card->longname);
+
+
+
+ bcd2000_init_midi(bcd2k);
+
+
+ err = snd_card_register(card);
+ if (err < 0)
+ goto probe_error;
+
+ usb_set_intfdata(interface, bcd2k);
+ devices_used |= 1 << card_index;
+
+ mutex_unlock(&devices_mutex);
+ return 0;
+
+probe_error:
+ bcd2000_free_usb_related_resources(bcd2k, interface);
+ snd_card_free(card);
+ mutex_unlock(&devices_mutex);
+ return err;
+}
+
+static void bcd2000_disconnect(struct usb_interface *interface)
+{
+ struct bcd2000 *bcd2k = usb_get_intfdata(interface);
+ struct list_head *midi;
+
+ if (!bcd2k)
+ return;
+
+ bcd2000_close_midi(bcd2k);
+
+ mutex_lock(&devices_mutex);
+
+ /* make sure that userspace cannot create new requests */
+ snd_card_disconnect(bcd2k->card);
+
+ /* make sure that there are no pending USB requests */
+ list_for_each(midi, &bcd2k->midi_list)
+ snd_usbmidi_disconnect(midi);
+
+ bcd2000_free_usb_related_resources(bcd2k, interface);
+
+ devices_used &= ~(1 << bcd2k->card_index);
+
+ snd_card_free_when_closed(bcd2k->card);
+
+ mutex_unlock(&devices_mutex);
+}
+
+static struct usb_driver bcd2000_driver = {
+ .name = DEVICE_SHORTNAME,
+ .probe = bcd2000_probe,
+ .disconnect = bcd2000_disconnect,
+ .id_table = id_table,
+};
+
+static int __init bcd2000_init(void)
+{
+ int retval = 0;
+
+ retval = usb_register(&bcd2000_driver);
+ if (retval)
+ snd_printk(KERN_INFO "usb_register failed. Error: %d", retval);
+ return retval;
+}
+
+static void __exit bcd2000_exit(void)
+{
+ usb_deregister(&bcd2000_driver);
+}
+
+module_init(bcd2000_init);
+module_exit(bcd2000_exit);
+
+MODULE_DEVICE_TABLE(usb, id_table);
+MODULE_AUTHOR("Mario Kicherer, dev at kicherer.org");
+MODULE_DESCRIPTION("Behringer BCD2000 driver");
+MODULE_LICENSE("GPL");
--
1.8.3.2
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