text: /*
   * tascam.c - a part of driver for TASCAM FireWire series
   *
   * Copyright (c) 2015 Takashi Sakamoto
   *
   * Licensed under the terms of the GNU General Public License, version 2.
   */
  
  #include "tascam.h"
  
  MODULE_DESCRIPTION("TASCAM FireWire series Driver");
  MODULE_AUTHOR("Takashi Sakamoto <o-takashi@sakamocchi.jp>");
  MODULE_LICENSE("GPL v2");
  
  static const struct snd_tscm_spec model_specs[] = {
  	{
  		.name = "FW-1884",
  		.has_adat = true,
  		.has_spdif = true,
  		.pcm_capture_analog_channels = 8,
  		.pcm_playback_analog_channels = 8,
  		.midi_capture_ports = 4,
  		.midi_playback_ports = 4,
  	},
  	{
  		.name = "FW-1082",
  		.has_adat = false,
  		.has_spdif = true,
  		.pcm_capture_analog_channels = 8,
  		.pcm_playback_analog_channels = 2,
  		.midi_capture_ports = 2,
  		.midi_playback_ports = 2,
  	},
  	{
  		.name = "FW-1804",
  		.has_adat = true,
  		.has_spdif = true,
  		.pcm_capture_analog_channels = 8,
  		.pcm_playback_analog_channels = 2,
  		.midi_capture_ports = 2,
  		.midi_playback_ports = 4,
  	},
  };
  
  static int identify_model(struct snd_tscm *tscm)
  {
  	struct fw_device *fw_dev = fw_parent_device(tscm->unit);
  	const u32 *config_rom = fw_dev->config_rom;
  	char model[9];
  	unsigned int i;
  	u8 c;
  
  	if (fw_dev->config_rom_length < 30) {
  		dev_err(&tscm->unit->device,
  			"Configuration ROM is too short.\n");
  		return -ENODEV;
  	}
  
  	/* Pick up model name from certain addresses. */
  	for (i = 0; i < 8; i++) {
  		c = config_rom[28 + i / 4] >> (24 - 8 * (i % 4));
  		if (c == '\0')
  			break;
  		model[i] = c;
  	}
  	model[i] = '\0';
  
  	for (i = 0; i < ARRAY_SIZE(model_specs); i++) {
  		if (strcmp(model, model_specs[i].name) == 0) {
  			tscm->spec = &model_specs[i];
  			break;
  		}
  	}
  	if (tscm->spec == NULL)
  		return -ENODEV;
  
  	strcpy(tscm->card->driver, "FW-TASCAM");
  	strcpy(tscm->card->shortname, model);
  	strcpy(tscm->card->mixername, model);
  	snprintf(tscm->card->longname, sizeof(tscm->card->longname),
  		 "TASCAM %s, GUID %08x%08x at %s, S%d", model,
  		 fw_dev->config_rom[3], fw_dev->config_rom[4],
  		 dev_name(&tscm->unit->device), 100 << fw_dev->max_speed);
  
  	return 0;
  }
  
  static void tscm_free(struct snd_tscm *tscm)
  {
  	snd_tscm_transaction_unregister(tscm);
  	snd_tscm_stream_destroy_duplex(tscm);
  
  	fw_unit_put(tscm->unit);
  
  	mutex_destroy(&tscm->mutex);
  }
  
  static void tscm_card_free(struct snd_card *card)
  {
  	tscm_free(card->private_data);
  }
  
  static void do_registration(struct work_struct *work)
  {
  	struct snd_tscm *tscm = container_of(work, struct snd_tscm, dwork.work);
  	int err;
  
  	err = snd_card_new(&tscm->unit->device, -1, NULL, THIS_MODULE, 0,
  			   &tscm->card);
  	if (err < 0)
  		return;
  
  	err = identify_model(tscm);
  	if (err < 0)
  		goto error;
  
  	err = snd_tscm_transaction_register(tscm);
  	if (err < 0)
  		goto error;
  
  	err = snd_tscm_stream_init_duplex(tscm);
  	if (err < 0)
  		goto error;
  
  	snd_tscm_proc_init(tscm);
  
  	err = snd_tscm_create_pcm_devices(tscm);
  	if (err < 0)
  		goto error;
  
  	err = snd_tscm_create_midi_devices(tscm);
  	if (err < 0)
  		goto error;
  
  	err = snd_tscm_create_hwdep_device(tscm);
  	if (err < 0)
  		goto error;
  
  	err = snd_card_register(tscm->card);
  	if (err < 0)
  		goto error;
  
  	/*
  	 * After registered, tscm instance can be released corresponding to
  	 * releasing the sound card instance.
  	 */
  	tscm->card->private_free = tscm_card_free;
  	tscm->card->private_data = tscm;
  	tscm->registered = true;
  
  	return;
  error:
  	snd_tscm_transaction_unregister(tscm);
  	snd_tscm_stream_destroy_duplex(tscm);
  	snd_card_free(tscm->card);
  	dev_info(&tscm->unit->device,
  		 "Sound card registration failed: %d\n", err);
  }
  
  static int snd_tscm_probe(struct fw_unit *unit,
  			   const struct ieee1394_device_id *entry)
  {
  	struct snd_tscm *tscm;
  
  	/* Allocate this independent of sound card instance. */
  	tscm = kzalloc(sizeof(struct snd_tscm), GFP_KERNEL);
  	if (tscm == NULL)
  		return -ENOMEM;
  
  	/* initialize myself */
  	tscm->unit = fw_unit_get(unit);
  	dev_set_drvdata(&unit->device, tscm);
  
  	mutex_init(&tscm->mutex);
  	spin_lock_init(&tscm->lock);
  	init_waitqueue_head(&tscm->hwdep_wait);
  
  	/* Allocate and register this sound card later. */
  	INIT_DEFERRABLE_WORK(&tscm->dwork, do_registration);
  	snd_fw_schedule_registration(unit, &tscm->dwork);
  
  	return 0;
  }
  
  static void snd_tscm_update(struct fw_unit *unit)
  {
  	struct snd_tscm *tscm = dev_get_drvdata(&unit->device);
  
  	/* Postpone a workqueue for deferred registration. */
  	if (!tscm->registered)
  		snd_fw_schedule_registration(unit, &tscm->dwork);
  
  	snd_tscm_transaction_reregister(tscm);
  
  	/*
  	 * After registration, userspace can start packet streaming, then this
  	 * code block works fine.
  	 */
  	if (tscm->registered) {
  		mutex_lock(&tscm->mutex);
  		snd_tscm_stream_update_duplex(tscm);
  		mutex_unlock(&tscm->mutex);
  	}
  }
  
  static void snd_tscm_remove(struct fw_unit *unit)
  {
  	struct snd_tscm *tscm = dev_get_drvdata(&unit->device);
  
  	/*
  	 * Confirm to stop the work for registration before the sound card is
  	 * going to be released. The work is not scheduled again because bus
  	 * reset handler is not called anymore.
  	 */
  	cancel_delayed_work_sync(&tscm->dwork);
  
  	if (tscm->registered) {
  		/* No need to wait for releasing card object in this context. */
  		snd_card_free_when_closed(tscm->card);
  	} else {
  		/* Don't forget this case. */
  		tscm_free(tscm);
  	}
  }
  
  static const struct ieee1394_device_id snd_tscm_id_table[] = {
  	{
  		.match_flags = IEEE1394_MATCH_VENDOR_ID |
  			       IEEE1394_MATCH_SPECIFIER_ID,
  		.vendor_id = 0x00022e,
  		.specifier_id = 0x00022e,
  	},
  	/* FE-08 requires reverse-engineering because it just has faders. */
  	{}
  };
  MODULE_DEVICE_TABLE(ieee1394, snd_tscm_id_table);
  
  static struct fw_driver tscm_driver = {
  	.driver = {
  		.owner = THIS_MODULE,
  		.name = "snd-firewire-tascam",
  		.bus = &fw_bus_type,
  	},
  	.probe    = snd_tscm_probe,
  	.update   = snd_tscm_update,
  	.remove   = snd_tscm_remove,
  	.id_table = snd_tscm_id_table,
  };
  
  static int __init snd_tscm_init(void)
  {
  	return driver_register(&tscm_driver.driver);
  }
  
  static void __exit snd_tscm_exit(void)
  {
  	driver_unregister(&tscm_driver.driver);
  }
  
  module_init(snd_tscm_init);
  module_exit(snd_tscm_exit);
  