[alsa-devel] [PATCH v9] MIDI driver for Behringer BCD2000 USB device
Takashi Iwai
tiwai at suse.de
Mon Apr 7 15:50:14 CEST 2014
At Mon, 07 Apr 2014 15:44:21 +0200,
Daniel Mack wrote:
>
> 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 at kicherer.org>
>
> FWIW, this looks good to me now. Clemens, Takashi, any further comments
> from your side?
Could you give your ack if the review is OK?
Then I'm going to merge the patch (but for post 3.15).
thanks,
Takashi
> 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 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/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 at kicherer.org");
> > +MODULE_DESCRIPTION("Behringer BCD2000 driver");
> > +MODULE_LICENSE("GPL");
> >
>
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