Re: [alsa-devel] [PATCH v9] MIDI driver for Behringer BCD2000 USB device

Hi Mario,

On 04/04/2014 08:40 PM, Mario Kicherer wrote:

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.

Signed-off-by: Mario Kicherer dev@kicherer.org

FWIW, this looks good to me now. Clemens, Takashi, any further comments from your side?

Thanks, Daniel

---

Changes since v8:

• module_usb_driver() macro for module initialization
• improved some comments

Changes since v7:

• replaced snd_card_create with snd_card_new

Changes since v6: - applied more style improvements

Changes since v5:

• use kernel bitmap functions for devices_used

Changes since v4:

• devices_used as array to support arbitrary number of SNDRV_CARDS
• removed unused array "enable"

Changes since v3: - applied style and snd_printk changes as suggested by Daniel Mack

Changes since v2: - applied more changes from Daniel Mack and Clemens Ladisch

Changes since v1: - fixed the various code style issues, thanks to Daniel Mack and checkpatch.pl.

sound/usb/Kconfig | 13 ++ sound/usb/Makefile | 2 +- sound/usb/bcd2000/Makefile | 3 + sound/usb/bcd2000/bcd2000.c | 461 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 478 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 e05a86b..d393153 100644 --- a/sound/usb/Kconfig +++ b/sound/usb/Kconfig @@ -147,5 +147,18 @@ config SND_USB_HIFACE To compile this driver as a module, choose M here: the module will be called snd-usb-hiface.

+config SND_BCD2000

• tristate "Behringer BCD2000 MIDI driver"
• 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-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..f09ccc0 --- /dev/null +++ b/sound/usb/bcd2000/Makefile @@ -0,0 +1,3 @@ +snd-bcd2000-y := bcd2000.o

+obj-$(CONFIG_SND_BCD2000) += snd-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..820d6ca --- /dev/null +++ b/sound/usb/bcd2000/bcd2000.c @@ -0,0 +1,461 @@ +/*

• • Behringer BCD2000 driver
• • Copyright (C) 2014 Mario Kicherer (dev@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/bitmap.h> +#include <linux/usb.h> +#include <linux/usb/audio.h> +#include <sound/core.h> +#include <sound/initval.h> +#include <sound/rawmidi.h>

+#define PREFIX "snd-bcd2000: " +#define BUFSIZE 64

+static struct usb_device_id id_table[] = {

• { USB_DEVICE(0x1397, 0x00bd) },
• { },

+};

+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;
• 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];
• struct urb *midi_out_urb;
• struct urb *midi_in_urb;
• struct usb_anchor anchor;

+};

+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; +static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;

+static DEFINE_MUTEX(devices_mutex); +DECLARE_BITMAP(devices_used, SNDRV_CARDS); +static struct usb_driver bcd2000_driver;

+#ifdef CONFIG_SND_DEBUG +static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) +{

• print_hex_dump(KERN_DEBUG, prefix,

• 	DUMP_PREFIX_NONE, 16, 1,
  

• 	buf, len, false);
  

+} +#else +static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) {} +#endif

+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;

+}

+/* (de)register midi substream from client */ +static void bcd2000_midi_input_trigger(struct snd_rawmidi_substream *substream,

• 				int up)
  

+{

• struct bcd2000 *bcd2k = substream->rmidi->private_data;
• bcd2k->midi_receive_substream = up ? substream : NULL;

+}

+static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k,

• 		const unsigned char *buf, unsigned int buf_len)
  

+{

• unsigned int payload_length, tocopy;
• struct snd_rawmidi_substream *midi_receive_substream;
• midi_receive_substream = ACCESS_ONCE(bcd2k->midi_receive_substream);
• if (!midi_receive_substream)

• return;
  

• bcd2000_dump_buffer(PREFIX "received from device: ", buf, buf_len);
• if (buf_len < 2)

• return;
  

• payload_length = buf[0];
• /* ignore packets without payload */
• if (payload_length == 0)

• return;
  

• tocopy = min(payload_length, buf_len-1);
• bcd2000_dump_buffer(PREFIX "sending to userspace: ",

• 			&buf[1], tocopy);
  

• snd_rawmidi_receive(midi_receive_substream,

• 			&buf[1], tocopy);
  

+}

+static void bcd2000_midi_send(struct bcd2000 *bcd2k) +{

• int len, ret;
• struct snd_rawmidi_substream *midi_out_substream;
• BUILD_BUG_ON(sizeof(device_cmd_prefix) >= BUFSIZE);
• midi_out_substream = ACCESS_ONCE(bcd2k->midi_out_substream);
• if (!midi_out_substream)

• return;
  

• /* copy command prefix 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(midi_out_substream,

• 		bcd2k->midi_out_buf + 3, BUFSIZE - 3);
  

• if (len < 0)

• dev_err(&bcd2k->dev->dev, "%s: snd_rawmidi_transmit error %d\n",
  

• 		__func__, len);
  

• if (len <= 0)

• return;
  

• /* set payload length */
• bcd2k->midi_out_buf[2] = len;
• bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
• bcd2000_dump_buffer(PREFIX "sending to device: ",

• 	bcd2k->midi_out_buf, len+3);
  

• /* 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__, midi_out_substream, ret, len);
  

• else

• bcd2k->midi_out_active = 1;
  

+}

+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_kill_urb(bcd2k->midi_out_urb);
  

• bcd2k->midi_out_active = 0;
  

• }
• return 0;

+}

+/* (de)register midi substream from client */ +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;
  

• /* check if there is data userspace wants to send */
  

• if (!bcd2k->midi_out_active)
  

• 	bcd2000_midi_send(bcd2k);
  

• } else {

• bcd2k->midi_out_substream = NULL;
  

• }

+}

+static void bcd2000_output_complete(struct urb *urb) +{

• struct bcd2000 *bcd2k = urb->context;
• bcd2k->midi_out_active = 0;
• if (urb->status)

• dev_warn(&urb->dev->dev,
  

• 	PREFIX "output urb->status: %d\n", urb->status);
  

• if (urb->status == -ESHUTDOWN)

• return;
  

• /* check if there is more data userspace wants to send */
• bcd2000_midi_send(bcd2k);

+}

+static void bcd2000_input_complete(struct urb *urb) +{

• int ret;
• struct bcd2000 *bcd2k = urb->context;
• if (urb->status)

• dev_warn(&urb->dev->dev,
  

• 	PREFIX "input urb->status: %i\n", urb->status);
  

• if (!bcd2k || urb->status == -ESHUTDOWN)

• return;
  

• if (urb->actual_length > 0)

• bcd2000_midi_handle_input(bcd2k, urb->transfer_buffer,
  

• 			urb->actual_length);
  

• /* return URB to device */
• ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
• if (ret < 0)

• dev_err(&bcd2k->dev->dev, PREFIX
  

• 	"%s: usb_submit_urb() failed, ret=%d\n",
  

• 	__func__, ret);
  

+}

+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;
• init_usb_anchor(&bcd2k->anchor);
• usb_anchor_urb(bcd2k->midi_out_urb, &bcd2k->anchor);
• usb_anchor_urb(bcd2k->midi_in_urb, &bcd2k->anchor);
• /* 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_KERNEL);
• if (ret < 0)

• dev_err(&bcd2k->dev->dev, PREFIX
  

• 	"%s: usb_submit_urb() out failed, ret=%d: ",
  

• 	__func__, ret);
  

• else

• bcd2k->midi_out_active = 1;
  

• /* pass URB to device to enable button and controller events */
• ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_KERNEL);
• if (ret < 0)

• dev_err(&bcd2k->dev->dev, PREFIX
  

• 	"%s: usb_submit_urb() in failed, ret=%d: ",
  

• 	__func__, ret);
  

• /* ensure initialization is finished */
• usb_wait_anchor_empty_timeout(&bcd2k->anchor, 1000);

+}

+static int 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 ret;
  

• 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);
• if (!bcd2k->midi_in_urb || !bcd2k->midi_out_urb) {

• dev_err(&bcd2k->dev->dev, PREFIX "usb_alloc_urb failed\n");
  

• return -ENOMEM;
  

• }
• usb_fill_int_urb(bcd2k->midi_in_urb, bcd2k->dev,

• 		usb_rcvintpipe(bcd2k->dev, 0x81),
  

• 		bcd2k->midi_in_buf, BUFSIZE,
  

• 		bcd2000_input_complete, bcd2k, 1);
  

• usb_fill_int_urb(bcd2k->midi_out_urb, bcd2k->dev,

• 		usb_sndintpipe(bcd2k->dev, 0x1),
  

• 		bcd2k->midi_out_buf, BUFSIZE,
  

• 		bcd2000_output_complete, bcd2k, 1);
  

• bcd2000_init_device(bcd2k);
• return 0;

+}

+static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,

• 				struct usb_interface *interface)
  

+{

• /* usb_kill_urb not necessary, urb is aborted automatically */
• usb_free_urb(bcd2k->midi_out_urb);
• usb_free_urb(bcd2k->midi_in_urb);
• if (bcd2k->intf) {

• usb_set_intfdata(bcd2k->intf, NULL);
  

• bcd2k->intf = NULL;
  

• }

+}

+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 (!test_bit(card_index, devices_used))
  

• 	break;
  

• if (card_index >= SNDRV_CARDS) {

• mutex_unlock(&devices_mutex);
  

• return -ENOENT;
  

• }
• err = snd_card_new(&interface->dev, index[card_index], id[card_index],

• 	THIS_MODULE, sizeof(*bcd2k), &card);
  

• if (err < 0) {

• mutex_unlock(&devices_mutex);
  

• return err;
  

• }
• bcd2k = card->private_data;
• bcd2k->dev = interface_to_usbdev(interface);
• bcd2k->card = card;
• bcd2k->card_index = card_index;
• bcd2k->intf = interface;
• snd_card_set_dev(card, &interface->dev);
• strncpy(card->driver, "snd-bcd2000", sizeof(card->driver));
• strncpy(card->shortname, "BCD2000", sizeof(card->shortname));
• usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
• snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),

•     "Behringer BCD2000 at %s",
  

• 	usb_path);
  

• err = bcd2000_init_midi(bcd2k);
• if (err < 0)

• goto probe_error;
  

• err = snd_card_register(card);
• if (err < 0)

• goto probe_error;
  

• usb_set_intfdata(interface, bcd2k);
• set_bit(card_index, devices_used);
• mutex_unlock(&devices_mutex);
• return 0;

+probe_error:

• dev_info(&bcd2k->dev->dev, PREFIX "error during probing");
• 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);
• if (!bcd2k)

• return;
  

• mutex_lock(&devices_mutex);
• /* make sure that userspace cannot create new requests */
• snd_card_disconnect(bcd2k->card);
• bcd2000_free_usb_related_resources(bcd2k, interface);
• clear_bit(bcd2k->card_index, devices_used);
• snd_card_free_when_closed(bcd2k->card);
• mutex_unlock(&devices_mutex);

+}

+static struct usb_driver bcd2000_driver = {

• .name = "snd-bcd2000",
• .probe = bcd2000_probe,
• .disconnect = bcd2000_disconnect,
• .id_table = id_table,

+};

+module_usb_driver(bcd2000_driver);

+MODULE_DEVICE_TABLE(usb, id_table); +MODULE_AUTHOR("Mario Kicherer, dev@kicherer.org"); +MODULE_DESCRIPTION("Behringer BCD2000 driver"); +MODULE_LICENSE("GPL");