/*
   *  Dummy soundcard for virtual rawmidi devices
   *
   *  Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>
   *
   *   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.
   *
   *   You should have received a copy of the GNU General Public License
   *   along with this program; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   *
   */
  
  /*
   * VIRTUAL RAW MIDI DEVICE CARDS
   *
   * This dummy card contains up to 4 virtual rawmidi devices.
   * They are not real rawmidi devices but just associated with sequencer
   * clients, so that any input/output sources can be connected as a raw
   * MIDI device arbitrary.
   * Also, multiple access is allowed to a single rawmidi device.
   *
   * Typical usage is like following:
   * - Load snd-virmidi module.
   *	# modprobe snd-virmidi index=2
   *   Then, sequencer clients 72:0 to 75:0 will be created, which are
   *   mapped from /dev/snd/midiC1D0 to /dev/snd/midiC1D3, respectively.
   *
   * - Connect input/output via aconnect.
   *	% aconnect 64:0 72:0	# keyboard input redirection 64:0 -> 72:0
   *	% aconnect 72:0 65:0	# output device redirection 72:0 -> 65:0
   *
   * - Run application using a midi device (eg. /dev/snd/midiC1D0)
   */
  
  #include <linux/init.h>
  #include <linux/wait.h>
  #include <linux/err.h>
  #include <linux/platform_device.h>
  #include <linux/module.h>
  #include <sound/core.h>
  #include <sound/seq_kernel.h>
  #include <sound/seq_virmidi.h>
  #include <sound/initval.h>
  
  /* hack: OSS defines midi_devs, so undefine it (versioned symbols) */
  #undef midi_devs
  
  MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
  MODULE_DESCRIPTION("Dummy soundcard for virtual rawmidi devices");
  MODULE_LICENSE("GPL");
  MODULE_SUPPORTED_DEVICE("{{ALSA,Virtual rawmidi device}}");
  
  #define MAX_MIDI_DEVICES	4
  
  static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
  static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
  static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 4};
  
  module_param_array(index, int, NULL, 0444);
  MODULE_PARM_DESC(index, "Index value for virmidi soundcard.");
  module_param_array(id, charp, NULL, 0444);
  MODULE_PARM_DESC(id, "ID string for virmidi soundcard.");
  module_param_array(enable, bool, NULL, 0444);
  MODULE_PARM_DESC(enable, "Enable this soundcard.");
  module_param_array(midi_devs, int, NULL, 0444);
  MODULE_PARM_DESC(midi_devs, "MIDI devices # (1-4)");
  
  struct snd_card_virmidi {
  	struct snd_card *card;
  	struct snd_rawmidi *midi[MAX_MIDI_DEVICES];
  };
  
  static struct platform_device *devices[SNDRV_CARDS];
  
  
  static int snd_virmidi_probe(struct platform_device *devptr)
  {
  	struct snd_card *card;
  	struct snd_card_virmidi *vmidi;
  	int idx, err;
  	int dev = devptr->id;
  
  	err = snd_card_create(index[dev], id[dev], THIS_MODULE,
  			      sizeof(struct snd_card_virmidi), &card);
  	if (err < 0)
  		return err;
  	vmidi = card->private_data;
  	vmidi->card = card;
  
  	if (midi_devs[dev] > MAX_MIDI_DEVICES) {
  		snd_printk(KERN_WARNING
  			   "too much midi devices for virmidi %d: "
  			   "force to use %d
  ", dev, MAX_MIDI_DEVICES);
  		midi_devs[dev] = MAX_MIDI_DEVICES;
  	}
  	for (idx = 0; idx < midi_devs[dev]; idx++) {
  		struct snd_rawmidi *rmidi;
  		struct snd_virmidi_dev *rdev;
  		if ((err = snd_virmidi_new(card, idx, &rmidi)) < 0)
  			goto __nodev;
  		rdev = rmidi->private_data;
  		vmidi->midi[idx] = rmidi;
  		strcpy(rmidi->name, "Virtual Raw MIDI");
  		rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
  	}
  	
  	strcpy(card->driver, "VirMIDI");
  	strcpy(card->shortname, "VirMIDI");
  	sprintf(card->longname, "Virtual MIDI Card %i", dev + 1);
  
  	snd_card_set_dev(card, &devptr->dev);
  
  	if ((err = snd_card_register(card)) == 0) {
  		platform_set_drvdata(devptr, card);
  		return 0;
  	}
        __nodev:
  	snd_card_free(card);
  	return err;
  }
  
  static int snd_virmidi_remove(struct platform_device *devptr)
  {
  	snd_card_free(platform_get_drvdata(devptr));
  	return 0;
  }
  
  #define SND_VIRMIDI_DRIVER	"snd_virmidi"
  
  static struct platform_driver snd_virmidi_driver = {
  	.probe		= snd_virmidi_probe,
  	.remove		= snd_virmidi_remove,
  	.driver		= {
  		.name	= SND_VIRMIDI_DRIVER,
  		.owner	= THIS_MODULE,
  	},
  };
  
  static void snd_virmidi_unregister_all(void)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(devices); ++i)
  		platform_device_unregister(devices[i]);
  	platform_driver_unregister(&snd_virmidi_driver);
  }
  
  static int __init alsa_card_virmidi_init(void)
  {
  	int i, cards, err;
  
  	if ((err = platform_driver_register(&snd_virmidi_driver)) < 0)
  		return err;
  
  	cards = 0;
  	for (i = 0; i < SNDRV_CARDS; i++) {
  		struct platform_device *device;
  		if (! enable[i])
  			continue;
  		device = platform_device_register_simple(SND_VIRMIDI_DRIVER,
  							 i, NULL, 0);
  		if (IS_ERR(device))
  			continue;
  		if (!platform_get_drvdata(device)) {
  			platform_device_unregister(device);
  			continue;
  		}
  		devices[i] = device;
  		cards++;
  	}
  	if (!cards) {
  #ifdef MODULE
  		printk(KERN_ERR "Card-VirMIDI soundcard not found or device busy
  ");
  #endif
  		snd_virmidi_unregister_all();
  		return -ENODEV;
  	}
  	return 0;
  }
  
  static void __exit alsa_card_virmidi_exit(void)
  {
  	snd_virmidi_unregister_all();
  }
  
  module_init(alsa_card_virmidi_init)
  module_exit(alsa_card_virmidi_exit)