Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Behringer BCD2000 driver
 *
 *   Copyright (C) 2014 Mario Kicherer (dev@kicherer.org)
 */
 
#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 const struct usb_device_id id_table[] = {
<------>{ USB_DEVICE(0x1397, 0x00bd) },
<------>{ },
};
 
static const unsigned char device_cmd_prefix[] = {0x03, 0x00};
 
static const 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);
static 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 = READ_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 = READ_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 const struct snd_rawmidi_ops bcd2000_midi_output = {
<------>.open =    bcd2000_midi_output_open,
<------>.close =   bcd2000_midi_output_close,
<------>.trigger = bcd2000_midi_output_trigger,
};
 
static const 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);
 
<------>/* sanity checks of EPs before actually submitting */
<------>if (usb_urb_ep_type_check(bcd2k->midi_in_urb) ||
<------>    usb_urb_ep_type_check(bcd2k->midi_out_urb)) {
<------><------>dev_err(&bcd2k->dev->dev, "invalid MIDI EP\n");
<------><------>return -EINVAL;
<------>}
 
<------>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");