/*
 *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
 *  Routines for control of EMU10K1 MPU-401 in UART mode
 *
 *
 *   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
 *
 */

#define __NO_VERSION__
#include <sound/driver.h>
#include <linux/time.h>
#include <sound/core.h>
#include <sound/emu10k1.h>

#define EMU10K1_MIDI_MODE_INPUT		(1<<0)
#define EMU10K1_MIDI_MODE_OUTPUT	(1<<1)

static inline unsigned char mpu401_read(struct snd_emu10k1 *emu, struct snd_emu10k1_midi *mpu, int idx)
{
    if (emu->audigy)
        return (unsigned char)snd_emu10k1_ptr_read(emu, mpu->port + idx, 0);
    else
        return inb(emu->port + mpu->port + idx);
}

static inline void mpu401_write(struct snd_emu10k1 *emu, struct snd_emu10k1_midi *mpu, int data, int idx)
{
    if (emu->audigy)
        snd_emu10k1_ptr_write(emu, mpu->port + idx, 0, data);
    else
        outb(data, emu->port + mpu->port + idx);
}

#define mpu401_write_data(emu, mpu, data)	mpu401_write(emu, mpu, data, 0)
#define mpu401_write_cmd(emu, mpu, data)	mpu401_write(emu, mpu, data, 1)
#define mpu401_read_data(emu, mpu)		mpu401_read(emu, mpu, 0)
#define mpu401_read_stat(emu, mpu)		mpu401_read(emu, mpu, 1)

#define mpu401_input_avail(emu,mpu)	(!(mpu401_read_stat(emu,mpu) & 0x80))
#define mpu401_output_ready(emu,mpu)	(!(mpu401_read_stat(emu,mpu) & 0x40))

#define MPU401_RESET		0xff
#define MPU401_ENTER_UART	0x3f
#define MPU401_ACK		0xfe

static void mpu401_clear_rx(struct snd_emu10k1 *emu, struct snd_emu10k1_midi *mpu)
{
    int timeout = 100000;
    for (; timeout > 0 && mpu401_input_avail(emu, mpu); timeout--)
        mpu401_read_data(emu, mpu);
#ifdef CONFIG_SND_DEBUG
    if (timeout <= 0)
        snd_printk(KERN_ERR "cmd: clear rx timeout (status = 0x%x)\n", mpu401_read_stat(emu, mpu));
#endif
}

/*

*/

static void do_emu10k1_midi_interrupt(struct snd_emu10k1 *emu, struct snd_emu10k1_midi *midi, unsigned int status)
{
    unsigned char byte;

    if (midi->rmidi == NULL) {
        snd_emu10k1_intr_disable(emu, midi->tx_enable | midi->rx_enable);
        return;
    }

    spin_lock(&midi->input_lock);
    if ((status & midi->ipr_rx) && mpu401_input_avail(emu, midi)) {
        if (!(midi->midi_mode & EMU10K1_MIDI_MODE_INPUT)) {
            mpu401_clear_rx(emu, midi);
        } else {
            byte = mpu401_read_data(emu, 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) && mpu401_output_ready(emu, midi)) {
        if (midi->substream_output &&
            snd_rawmidi_transmit(midi->substream_output, &byte, 1) == 1) {
            mpu401_write_data(emu, midi, byte);
        } else {
            snd_emu10k1_intr_disable(emu, midi->tx_enable);
        }
    }
    spin_unlock(&midi->output_lock);
}

static void snd_emu10k1_midi_interrupt(struct snd_emu10k1 *emu, unsigned int status)
{
    do_emu10k1_midi_interrupt(emu, &emu->midi, status);
}

static void snd_emu10k1_midi_interrupt2(struct snd_emu10k1 *emu, unsigned int status)
{
    do_emu10k1_midi_interrupt(emu, &emu->midi2, status);
}

static int snd_emu10k1_midi_cmd(struct snd_emu10k1 * emu, struct snd_emu10k1_midi *midi, unsigned char cmd, int ack)
{
    unsigned long flags;
    int timeout, ok;

    spin_lock_irqsave(&midi->input_lock, flags);
    mpu401_write_data(emu, midi, 0x00);
    /* mpu401_clear_rx(emu, midi); */

    mpu401_write_cmd(emu, midi, cmd);
    if (ack) {
        ok = 0;
        timeout = 10000;
        while (!ok && timeout-- > 0) {
            if (mpu401_input_avail(emu, midi)) {
                if (mpu401_read_data(emu, midi) == MPU401_ACK)
                    ok = 1;
            }
        }
        if (!ok && mpu401_read_data(emu, midi) == MPU401_ACK)
            ok = 1;
    } else {
        ok = 1;
    }
    spin_unlock_irqrestore(&midi->input_lock, flags);
    if (!ok) {
        snd_printk(KERN_ERR "midi_cmd: 0x%x failed at 0x%lx (status = 0x%x, data = 0x%x)!!!\n",
                   cmd, emu->port,
                   mpu401_read_stat(emu, midi),
                   mpu401_read_data(emu, midi));
        return 1;
    }
    return 0;
}

static int snd_emu10k1_midi_input_open(struct snd_rawmidi_substream *substream)
{
    struct snd_emu10k1 *emu;
    struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
    unsigned long flags;

    emu = midi->emu;
    snd_assert(emu, return -ENXIO);
    spin_lock_irqsave(&midi->open_lock, flags);
    midi->midi_mode |= EMU10K1_MIDI_MODE_INPUT;
    midi->substream_input = substream;
    if (!(midi->midi_mode & EMU10K1_MIDI_MODE_OUTPUT)) {
        spin_unlock_irqrestore(&midi->open_lock, flags);
        if (snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 1))
            goto error_out;
        if (snd_emu10k1_midi_cmd(emu, midi, MPU401_ENTER_UART, 1))
            goto error_out;
    } else {
        spin_unlock_irqrestore(&midi->open_lock, flags);
    }
    return 0;

    error_out:
        return -EIO;
}

static int snd_emu10k1_midi_output_open(struct snd_rawmidi_substream *substream)
{
    struct snd_emu10k1 *emu;
    struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
    unsigned long flags;

    emu = midi->emu;
    snd_assert(emu, return -ENXIO);
    spin_lock_irqsave(&midi->open_lock, flags);
    midi->midi_mode |= EMU10K1_MIDI_MODE_OUTPUT;
    midi->substream_output = substream;
    if (!(midi->midi_mode & EMU10K1_MIDI_MODE_INPUT)) {
        spin_unlock_irqrestore(&midi->open_lock, flags);
        if (snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 1))
            goto error_out;
        if (snd_emu10k1_midi_cmd(emu, midi, MPU401_ENTER_UART, 1))
            goto error_out;
    } else {
        spin_unlock_irqrestore(&midi->open_lock, flags);
    }
    return 0;

    error_out:
        return -EIO;
}

static int snd_emu10k1_midi_input_close(struct snd_rawmidi_substream *substream)
{
    struct snd_emu10k1 *emu;
    struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
    unsigned long flags;
    int err = 0;

    emu = midi->emu;
    snd_assert(emu, return -ENXIO);
    spin_lock_irqsave(&midi->open_lock, flags);
    snd_emu10k1_intr_disable(emu, midi->rx_enable);
    midi->midi_mode &= ~EMU10K1_MIDI_MODE_INPUT;
    midi->substream_input = NULL;
    if (!(midi->midi_mode & EMU10K1_MIDI_MODE_OUTPUT)) {
        spin_unlock_irqrestore(&midi->open_lock, flags);
        err = snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 0);
    } else {
        spin_unlock_irqrestore(&midi->open_lock, flags);
    }
    return err;
}

static int snd_emu10k1_midi_output_close(struct snd_rawmidi_substream *substream)
{
    struct snd_emu10k1 *emu;
    struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
    unsigned long flags;
    int err = 0;

    emu = midi->emu;
    snd_assert(emu, return -ENXIO);
    spin_lock_irqsave(&midi->open_lock, flags);
    snd_emu10k1_intr_disable(emu, midi->tx_enable);
    midi->midi_mode &= ~EMU10K1_MIDI_MODE_OUTPUT;
    midi->substream_output = NULL;
    if (!(midi->midi_mode & EMU10K1_MIDI_MODE_INPUT)) {
        spin_unlock_irqrestore(&midi->open_lock, flags);
        err = snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 0);
    } else {
        spin_unlock_irqrestore(&midi->open_lock, flags);
    }
    return err;
}

static void snd_emu10k1_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
{
    struct snd_emu10k1 *emu;
    struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
    emu = midi->emu;
    snd_assert(emu, return);

    if (up)
        snd_emu10k1_intr_enable(emu, midi->rx_enable);
    else
        snd_emu10k1_intr_disable(emu, midi->rx_enable);
}

static void snd_emu10k1_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
{
    struct snd_emu10k1 *emu;
    struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
    unsigned long flags;

    emu = midi->emu;
    snd_assert(emu, return);

    if (up) {
        int max = 4;
        unsigned char byte;

        /* try to send some amount of bytes here before interrupts */
        spin_lock_irqsave(&midi->output_lock, flags);
        while (max > 0) {
            if (mpu401_output_ready(emu, midi)) {
                if (!(midi->midi_mode & EMU10K1_MIDI_MODE_OUTPUT) ||
                    snd_rawmidi_transmit(substream, &byte, 1) != 1) {
                    /* no more data */
                    spin_unlock_irqrestore(&midi->output_lock, flags);
                    return;
                }
                mpu401_write_data(emu, midi, byte);
                max--;
            } else {
                break;
            }
        }
        spin_unlock_irqrestore(&midi->output_lock, flags);
        snd_emu10k1_intr_enable(emu, midi->tx_enable);
    } else {
        snd_emu10k1_intr_disable(emu, midi->tx_enable);
    }
}

/*

*/

static struct snd_rawmidi_ops snd_emu10k1_midi_output =
{
    .open =		snd_emu10k1_midi_output_open,
    .close =	snd_emu10k1_midi_output_close,
    .trigger =	snd_emu10k1_midi_output_trigger,
};

static struct snd_rawmidi_ops snd_emu10k1_midi_input =
{
    .open =		snd_emu10k1_midi_input_open,
    .close =	snd_emu10k1_midi_input_close,
    .trigger =	snd_emu10k1_midi_input_trigger,
};

static void snd_emu10k1_midi_free(struct snd_rawmidi *rmidi)
{
    struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)rmidi->private_data;
    midi->interrupt = NULL;
    midi->rmidi = NULL;
}

static int __devinit emu10k1_midi_init(struct snd_emu10k1 *emu, struct snd_emu10k1_midi *midi, int device, char *name)
{
    struct snd_rawmidi *rmidi;
    int err;

    if ((err = snd_rawmidi_new(emu->card, name, device, 1, 1, &rmidi)) < 0)
        return err;
    midi->emu = emu;
    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, &snd_emu10k1_midi_output);
    snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_emu10k1_midi_input);
    rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |
        SNDRV_RAWMIDI_INFO_INPUT |
        SNDRV_RAWMIDI_INFO_DUPLEX;
    rmidi->private_data = midi;
    rmidi->private_free = snd_emu10k1_midi_free;
    midi->rmidi = rmidi;
    return 0;
}

int __devinit snd_emu10k1_midi(struct snd_emu10k1 *emu)
{
    struct snd_emu10k1_midi *midi = &emu->midi;
    int err;

    if ((err = emu10k1_midi_init(emu, midi, 0, "EMU10K1 MPU-401 (UART)")) < 0)
        return err;

    midi->tx_enable = INTE_MIDITXENABLE;
    midi->rx_enable = INTE_MIDIRXENABLE;
    midi->port = MUDATA;
    midi->ipr_tx = IPR_MIDITRANSBUFEMPTY;
    midi->ipr_rx = IPR_MIDIRECVBUFEMPTY;
    midi->interrupt = snd_emu10k1_midi_interrupt;
    return 0;
}

int __devinit snd_emu10k1_audigy_midi(struct snd_emu10k1 *emu)
{
    struct snd_emu10k1_midi *midi;
    int err;

    midi = &emu->midi;
    if ((err = emu10k1_midi_init(emu, midi, 0, "Audigy MPU-401 (UART)")) < 0)
        return err;

    midi->tx_enable = INTE_MIDITXENABLE;
    midi->rx_enable = INTE_MIDIRXENABLE;
    midi->port = A_MUDATA1;
    midi->ipr_tx = IPR_MIDITRANSBUFEMPTY;
    midi->ipr_rx = IPR_MIDIRECVBUFEMPTY;
    midi->interrupt = snd_emu10k1_midi_interrupt;

    midi = &emu->midi2;
    if ((err = emu10k1_midi_init(emu, midi, 1, "Audigy MPU-401 #2")) < 0)
        return err;

    midi->tx_enable = INTE_A_MIDITXENABLE2;
    midi->rx_enable = INTE_A_MIDIRXENABLE2;
    midi->port = A_MUDATA2;
    midi->ipr_tx = IPR_A_MIDITRANSBUFEMPTY2;
    midi->ipr_rx = IPR_A_MIDIRECVBUFEMPTY2;
    midi->interrupt = snd_emu10k1_midi_interrupt2;
    return 0;
}
