ca_midi.c

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/* 
 *  Copyright 10/16/2005 Tilman Kranz <[email protected]>
 *  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 <[email protected]>
 *    emu10k1x: Copyright (c) by Francisco Moraes <[email protected]>
 *
 *   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)\n",
               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)!!!\n",
               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;
}