/* 
   *  Copyright 10/16/2005 Tilman Kranz <tilde@tk-sls.de>
   *  Creative Audio MIDI, for the CA0106 Driver
   *  Version: 0.0.1
   *
   *  Changelog:
   *    Implementation is based on mpu401 and emu10k1x and
   *    tested with ca0106.

   *    mpu401: Copyright (c) by Jaroslav Kysela <perex@perex.cz>

   *    emu10k1x: Copyright (c) by Francisco Moraes <fmoraes@nc.rr.com>

   *
   *   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
   *
   *
   */
  
  #include <linux/spinlock.h>

  #include <sound/core.h>
  #include <sound/rawmidi.h>
  
  #include "ca_midi.h"
  
  #define ca_midi_write_data(midi, data)	midi->write(midi, data, 0)
  #define ca_midi_write_cmd(midi, data)	midi->write(midi, data, 1)
  #define ca_midi_read_data(midi)		midi->read(midi, 0)
  #define ca_midi_read_stat(midi)		midi->read(midi, 1)
  #define ca_midi_input_avail(midi)	(!(ca_midi_read_stat(midi) & midi->input_avail))
  #define ca_midi_output_ready(midi)	(!(ca_midi_read_stat(midi) & midi->output_ready))

  static void ca_midi_clear_rx(struct snd_ca_midi *midi)

  {
  	int timeout = 100000;
  	for (; timeout > 0 && ca_midi_input_avail(midi); timeout--)
  		ca_midi_read_data(midi);
  #ifdef CONFIG_SND_DEBUG
  	if (timeout <= 0)

  		snd_printk(KERN_ERR "ca_midi_clear_rx: timeout (status = 0x%x)
  ",
  			   ca_midi_read_stat(midi));

  #endif
  }

  static void ca_midi_interrupt(struct snd_ca_midi *midi, unsigned int status)
  {

  	unsigned char byte;
  
  	if (midi->rmidi == NULL) {
  		midi->interrupt_disable(midi,midi->tx_enable | midi->rx_enable);
  		return;
  	}
  
  	spin_lock(&midi->input_lock);
  	if ((status & midi->ipr_rx) && ca_midi_input_avail(midi)) {
  		if (!(midi->midi_mode & CA_MIDI_MODE_INPUT)) {
  			ca_midi_clear_rx(midi);
  		} else {
  			byte = ca_midi_read_data(midi);
  			if(midi->substream_input)
  				snd_rawmidi_receive(midi->substream_input, &byte, 1);
  
  
  		}
  	}
  	spin_unlock(&midi->input_lock);
  
  	spin_lock(&midi->output_lock);
  	if ((status & midi->ipr_tx) && ca_midi_output_ready(midi)) {
  		if (midi->substream_output &&
  		    snd_rawmidi_transmit(midi->substream_output, &byte, 1) == 1) {
  			ca_midi_write_data(midi, byte);
  		} else {
  			midi->interrupt_disable(midi,midi->tx_enable);
  		}
  	}
  	spin_unlock(&midi->output_lock);
  
  }

  static void ca_midi_cmd(struct snd_ca_midi *midi, unsigned char cmd, int ack)

  {
  	unsigned long flags;
  	int timeout, ok;
  
  	spin_lock_irqsave(&midi->input_lock, flags);
  	ca_midi_write_data(midi, 0x00);
  	/* ca_midi_clear_rx(midi); */
  
  	ca_midi_write_cmd(midi, cmd);
  	if (ack) {
  		ok = 0;
  		timeout = 10000;
  		while (!ok && timeout-- > 0) {
  			if (ca_midi_input_avail(midi)) {
  				if (ca_midi_read_data(midi) == midi->ack)
  					ok = 1;
  			}
  		}
  		if (!ok && ca_midi_read_data(midi) == midi->ack)
  			ok = 1;
  	} else {
  		ok = 1;
  	}
  	spin_unlock_irqrestore(&midi->input_lock, flags);
  	if (!ok)
  		snd_printk(KERN_ERR "ca_midi_cmd: 0x%x failed at 0x%x (status = 0x%x, data = 0x%x)!!!
  ",
  			   cmd,
  			   midi->get_dev_id_port(midi->dev_id),
  			   ca_midi_read_stat(midi),
  			   ca_midi_read_data(midi));
  }

  static int ca_midi_input_open(struct snd_rawmidi_substream *substream)

  {

  	struct snd_ca_midi *midi = substream->rmidi->private_data;

  	unsigned long flags;
  	

  	if (snd_BUG_ON(!midi->dev_id))
  		return -ENXIO;

  	spin_lock_irqsave(&midi->open_lock, flags);
  	midi->midi_mode |= CA_MIDI_MODE_INPUT;
  	midi->substream_input = substream;
  	if (!(midi->midi_mode & CA_MIDI_MODE_OUTPUT)) {
  		spin_unlock_irqrestore(&midi->open_lock, flags);
  		ca_midi_cmd(midi, midi->reset, 1);
  		ca_midi_cmd(midi, midi->enter_uart, 1);
  	} else {
  		spin_unlock_irqrestore(&midi->open_lock, flags);
  	}
  	return 0;
  }

  static int ca_midi_output_open(struct snd_rawmidi_substream *substream)

  {

  	struct snd_ca_midi *midi = substream->rmidi->private_data;

  	unsigned long flags;

  	if (snd_BUG_ON(!midi->dev_id))
  		return -ENXIO;

  	spin_lock_irqsave(&midi->open_lock, flags);
  	midi->midi_mode |= CA_MIDI_MODE_OUTPUT;
  	midi->substream_output = substream;
  	if (!(midi->midi_mode & CA_MIDI_MODE_INPUT)) {
  		spin_unlock_irqrestore(&midi->open_lock, flags);
  		ca_midi_cmd(midi, midi->reset, 1);
  		ca_midi_cmd(midi, midi->enter_uart, 1);
  	} else {
  		spin_unlock_irqrestore(&midi->open_lock, flags);
  	}
  	return 0;
  }

  static int ca_midi_input_close(struct snd_rawmidi_substream *substream)

  {

  	struct snd_ca_midi *midi = substream->rmidi->private_data;

  	unsigned long flags;

  	if (snd_BUG_ON(!midi->dev_id))
  		return -ENXIO;

  	spin_lock_irqsave(&midi->open_lock, flags);
  	midi->interrupt_disable(midi,midi->rx_enable);
  	midi->midi_mode &= ~CA_MIDI_MODE_INPUT;
  	midi->substream_input = NULL;
  	if (!(midi->midi_mode & CA_MIDI_MODE_OUTPUT)) {
  		spin_unlock_irqrestore(&midi->open_lock, flags);
  		ca_midi_cmd(midi, midi->reset, 0);
  	} else {
  		spin_unlock_irqrestore(&midi->open_lock, flags);
  	}
  	return 0;
  }

  static int ca_midi_output_close(struct snd_rawmidi_substream *substream)

  {

  	struct snd_ca_midi *midi = substream->rmidi->private_data;

  	unsigned long flags;

  
  	if (snd_BUG_ON(!midi->dev_id))
  		return -ENXIO;

  	
  	spin_lock_irqsave(&midi->open_lock, flags);
  
  	midi->interrupt_disable(midi,midi->tx_enable);
  	midi->midi_mode &= ~CA_MIDI_MODE_OUTPUT;
  	midi->substream_output = NULL;
  	
  	if (!(midi->midi_mode & CA_MIDI_MODE_INPUT)) {
  		spin_unlock_irqrestore(&midi->open_lock, flags);
  		ca_midi_cmd(midi, midi->reset, 0);
  	} else {
  		spin_unlock_irqrestore(&midi->open_lock, flags);
  	}
  	return 0;
  }

  static void ca_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)

  {

  	struct snd_ca_midi *midi = substream->rmidi->private_data;

  
  	if (snd_BUG_ON(!midi->dev_id))
  		return;

  
  	if (up) {
  		midi->interrupt_enable(midi,midi->rx_enable);
  	} else {
  		midi->interrupt_disable(midi, midi->rx_enable);
  	}
  }

  static void ca_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)

  {

  	struct snd_ca_midi *midi = substream->rmidi->private_data;

  	unsigned long flags;

  	if (snd_BUG_ON(!midi->dev_id))
  		return;

  
  	if (up) {
  		int max = 4;
  		unsigned char byte;
  
  		spin_lock_irqsave(&midi->output_lock, flags);
  	
  		/* try to send some amount of bytes here before interrupts */
  		while (max > 0) {
  			if (ca_midi_output_ready(midi)) {
  				if (!(midi->midi_mode & CA_MIDI_MODE_OUTPUT) ||
  				    snd_rawmidi_transmit(substream, &byte, 1) != 1) {
  					/* no more data */
  					spin_unlock_irqrestore(&midi->output_lock, flags);
  					return;
  				}
  				ca_midi_write_data(midi, byte);
  				max--;
  			} else {
  				break;
  			}
  		}
  
  		spin_unlock_irqrestore(&midi->output_lock, flags);
  		midi->interrupt_enable(midi,midi->tx_enable);
  
  	} else {
  		midi->interrupt_disable(midi,midi->tx_enable);
  	}
  }

  static struct snd_rawmidi_ops ca_midi_output =

  {
  	.open =		ca_midi_output_open,
  	.close =	ca_midi_output_close,
  	.trigger =	ca_midi_output_trigger,
  };

  static struct snd_rawmidi_ops ca_midi_input =

  {
  	.open =		ca_midi_input_open,
  	.close =	ca_midi_input_close,
  	.trigger =	ca_midi_input_trigger,
  };

  static void ca_midi_free(struct snd_ca_midi *midi)
  {

  	midi->interrupt = NULL;
  	midi->interrupt_enable = NULL;
  	midi->interrupt_disable = NULL;
  	midi->read = NULL;
  	midi->write = NULL;
  	midi->get_dev_id_card = NULL;
  	midi->get_dev_id_port = NULL;
  	midi->rmidi = NULL;
  }

  static void ca_rmidi_free(struct snd_rawmidi *rmidi)

  {

  	ca_midi_free(rmidi->private_data);

  }

  int __devinit ca_midi_init(void *dev_id, struct snd_ca_midi *midi, int device, char *name)

  {

  	struct snd_rawmidi *rmidi;

  	int err;
  
  	if ((err = snd_rawmidi_new(midi->get_dev_id_card(midi->dev_id), name, device, 1, 1, &rmidi)) < 0)
  		return err;
  
  	midi->dev_id = dev_id;
  	midi->interrupt = ca_midi_interrupt;
  
  	spin_lock_init(&midi->open_lock);
  	spin_lock_init(&midi->input_lock);
  	spin_lock_init(&midi->output_lock);
  
  	strcpy(rmidi->name, name);
  	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &ca_midi_output);
  	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &ca_midi_input);
  	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |
  	                     SNDRV_RAWMIDI_INFO_INPUT |
  	                     SNDRV_RAWMIDI_INFO_DUPLEX;
  	rmidi->private_data = midi;
  	rmidi->private_free = ca_rmidi_free;
  	
  	midi->rmidi = rmidi;
  	return 0;
  }