/*
 * sound/oss/sb_midi.c
 *
 * The low level driver for the Sound Blaster DS chips.
 *
 *
 * Copyright (C) by Hannu Savolainen 1993-1997
 *
 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
 * Version 2 (June 1991). See the "COPYING" file distributed with this software
 * for more info.
 */

#include <linux/spinlock.h>

#include "sound_config.h"

#include "sb.h"
#undef SB_TEST_IRQ

/*
 * The DSP channel can be used either for input or output. Variable
 * 'sb_irq_mode' will be set when the program calls read or write first time
 * after open. Current version doesn't support mode changes without closing
 * and reopening the device. Support for this feature may be implemented in a
 * future version of this driver.
 */


static int sb_midi_open(int dev, int mode,
             void            (*input) (int dev, unsigned char data),
             void            (*output) (int dev)
)
{
        sb_devc *devc = midi_devs[dev]->devc;
        unsigned long flags;

        if (devc == NULL)
                return -ENXIO;

        spin_lock_irqsave(&devc->lock, flags);
        if (devc->opened)
        {
                spin_unlock_irqrestore(&devc->lock, flags);
                return -EBUSY;
        }
        devc->opened = 1;
        spin_unlock_irqrestore(&devc->lock, flags);

        devc->irq_mode = IMODE_MIDI;
        devc->midi_broken = 0;

        sb_dsp_reset(devc);

        if (!sb_dsp_command(devc, 0x35))        /* Start MIDI UART mode */
        {
                  devc->opened = 0;
                  return -EIO;
        }
        devc->intr_active = 1;

        if (mode & OPEN_READ)
        {
                devc->input_opened = 1;
                devc->midi_input_intr = input;
        }
        return 0;
}

static void sb_midi_close(int dev)
{
        sb_devc *devc = midi_devs[dev]->devc;
        unsigned long flags;

        if (devc == NULL)
                return;

        spin_lock_irqsave(&devc->lock, flags);
        sb_dsp_reset(devc);
        devc->intr_active = 0;
        devc->input_opened = 0;
        devc->opened = 0;
        spin_unlock_irqrestore(&devc->lock, flags);
}

static int sb_midi_out(int dev, unsigned char midi_byte)
{
        sb_devc *devc = midi_devs[dev]->devc;

        if (devc == NULL)
                return 1;

        if (devc->midi_broken)
                return 1;

        if (!sb_dsp_command(devc, midi_byte))
        {
                devc->midi_broken = 1;
                return 1;
        }
        return 1;
}

static int sb_midi_start_read(int dev)
{
        return 0;
}

static int sb_midi_end_read(int dev)
{
        sb_devc *devc = midi_devs[dev]->devc;

        if (devc == NULL)
                return -ENXIO;

        sb_dsp_reset(devc);
        devc->intr_active = 0;
        return 0;
}

static int sb_midi_ioctl(int dev, unsigned cmd, void __user *arg)
{
        return -EINVAL;
}

void sb_midi_interrupt(sb_devc * devc)
{
        unsigned long   flags;
        unsigned char   data;

        if (devc == NULL)
                return;

        spin_lock_irqsave(&devc->lock, flags);

        data = inb(DSP_READ);
        if (devc->input_opened)
                devc->midi_input_intr(devc->my_mididev, data);

        spin_unlock_irqrestore(&devc->lock, flags);
}

#define MIDI_SYNTH_NAME "Sound Blaster Midi"
#define MIDI_SYNTH_CAPS 0
#include "midi_synth.h"

static struct midi_operations sb_midi_operations =
{
        .owner          = THIS_MODULE,
        .info           = {"Sound Blaster", 0, 0, SNDCARD_SB},
        .converter      = &std_midi_synth,
        .in_info        = {0},
        .open           = sb_midi_open,
        .close          = sb_midi_close,
        .ioctl          = sb_midi_ioctl,
        .outputc        = sb_midi_out,
        .start_read     = sb_midi_start_read,
        .end_read       = sb_midi_end_read,
};

void sb_dsp_midi_init(sb_devc * devc, struct module *owner)
{
        int dev;

        if (devc->model < 2)    /* No MIDI support for SB 1.x */
                return;

        dev = sound_alloc_mididev();

        if (dev == -1)
        {
                printk(KERN_ERR "sb_midi: too many MIDI devices detected\n");
                return;
        }
        std_midi_synth.midi_dev = devc->my_mididev = dev;
        midi_devs[dev] = kmalloc(sizeof(struct midi_operations), GFP_KERNEL);
        if (midi_devs[dev] == NULL)
        {
                printk(KERN_WARNING "Sound Blaster:  failed to allocate MIDI memory.\n");
                sound_unload_mididev(dev);
                  return;
        }
        memcpy((char *) midi_devs[dev], (char *) &sb_midi_operations,
               sizeof(struct midi_operations));

        if (owner)
                        midi_devs[dev]->owner = owner;
        
        midi_devs[dev]->devc = devc;


        midi_devs[dev]->converter = kmalloc(sizeof(struct synth_operations), GFP_KERNEL);
        if (midi_devs[dev]->converter == NULL)
        {
                  printk(KERN_WARNING "Sound Blaster:  failed to allocate MIDI memory.\n");
                  kfree(midi_devs[dev]);
                  sound_unload_mididev(dev);
                  return;
        }
        memcpy((char *) midi_devs[dev]->converter, (char *) &std_midi_synth,
               sizeof(struct synth_operations));

        midi_devs[dev]->converter->id = "SBMIDI";
        sequencer_init();
}