gus_uart.c

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/*
 *  Copyright (c) by Jaroslav Kysela <[email protected]>
 *  Routines for the GF1 MIDI interface - like UART 6850
 *
 *
 *   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/delay.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <sound/core.h>
#include <sound/gus.h>

static void snd_gf1_interrupt_midi_in(struct snd_gus_card * gus)
{
    int count;
    unsigned char stat, data, byte;
    unsigned long flags;

    count = 10;
    while (count) {
        spin_lock_irqsave(&gus->uart_cmd_lock, flags);
        stat = snd_gf1_uart_stat(gus);
        if (!(stat & 0x01)) {   /* data in Rx FIFO? */
            spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
            count--;
            continue;
        }
        count = 100;    /* arm counter to new value */
        data = snd_gf1_uart_get(gus);
        if (!(gus->gf1.uart_cmd & 0x80)) {
            spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
            continue;
        }           
        if (stat & 0x10) {  /* framing error */
            gus->gf1.uart_framing++;
            spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
            continue;
        }
        byte = snd_gf1_uart_get(gus);
        spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
        snd_rawmidi_receive(gus->midi_substream_input, &byte, 1);
        if (stat & 0x20) {
            gus->gf1.uart_overrun++;
        }
    }
}

static void snd_gf1_interrupt_midi_out(struct snd_gus_card * gus)
{
    char byte;
    unsigned long flags;

    /* try unlock output */
    if (snd_gf1_uart_stat(gus) & 0x01)
        snd_gf1_interrupt_midi_in(gus);

    spin_lock_irqsave(&gus->uart_cmd_lock, flags);
    if (snd_gf1_uart_stat(gus) & 0x02) {    /* Tx FIFO free? */
        if (snd_rawmidi_transmit(gus->midi_substream_output, &byte, 1) != 1) {  /* no other bytes or error */
            snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x20); /* disable Tx interrupt */
        } else {
            snd_gf1_uart_put(gus, byte);
        }
    }
    spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
}

static void snd_gf1_uart_reset(struct snd_gus_card * gus, int close)
{
    snd_gf1_uart_cmd(gus, 0x03);    /* reset */
    if (!close && gus->uart_enable) {
        udelay(160);
        snd_gf1_uart_cmd(gus, 0x00);    /* normal operations */
    }
}

static int snd_gf1_uart_output_open(struct snd_rawmidi_substream *substream)
{
    unsigned long flags;
    struct snd_gus_card *gus;

    gus = substream->rmidi->private_data;
    spin_lock_irqsave(&gus->uart_cmd_lock, flags);
    if (!(gus->gf1.uart_cmd & 0x80)) {  /* input active? */
        snd_gf1_uart_reset(gus, 0);
    }
    gus->gf1.interrupt_handler_midi_out = snd_gf1_interrupt_midi_out;
    gus->midi_substream_output = substream;
    spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
#if 0
    snd_printk(KERN_DEBUG "write init - cmd = 0x%x, stat = 0x%x\n", gus->gf1.uart_cmd, snd_gf1_uart_stat(gus));
#endif
    return 0;
}

static int snd_gf1_uart_input_open(struct snd_rawmidi_substream *substream)
{
    unsigned long flags;
    struct snd_gus_card *gus;
    int i;

    gus = substream->rmidi->private_data;
    spin_lock_irqsave(&gus->uart_cmd_lock, flags);
    if (gus->gf1.interrupt_handler_midi_out != snd_gf1_interrupt_midi_out) {
        snd_gf1_uart_reset(gus, 0);
    }
    gus->gf1.interrupt_handler_midi_in = snd_gf1_interrupt_midi_in;
    gus->midi_substream_input = substream;
    if (gus->uart_enable) {
        for (i = 0; i < 1000 && (snd_gf1_uart_stat(gus) & 0x01); i++)
            snd_gf1_uart_get(gus);  /* clean Rx */
        if (i >= 1000)
            snd_printk(KERN_ERR "gus midi uart init read - cleanup error\n");
    }
    spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
#if 0
    snd_printk(KERN_DEBUG
           "read init - enable = %i, cmd = 0x%x, stat = 0x%x\n",
           gus->uart_enable, gus->gf1.uart_cmd, snd_gf1_uart_stat(gus));
    snd_printk(KERN_DEBUG
           "[0x%x] reg (ctrl/status) = 0x%x, reg (data) = 0x%x "
           "(page = 0x%x)\n",
           gus->gf1.port + 0x100, inb(gus->gf1.port + 0x100),
           inb(gus->gf1.port + 0x101), inb(gus->gf1.port + 0x102));
#endif
    return 0;
}

static int snd_gf1_uart_output_close(struct snd_rawmidi_substream *substream)
{
    unsigned long flags;
    struct snd_gus_card *gus;

    gus = substream->rmidi->private_data;
    spin_lock_irqsave(&gus->uart_cmd_lock, flags);
    if (gus->gf1.interrupt_handler_midi_in != snd_gf1_interrupt_midi_in)
        snd_gf1_uart_reset(gus, 1);
    snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_MIDI_OUT);
    gus->midi_substream_output = NULL;
    spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
    return 0;
}

static int snd_gf1_uart_input_close(struct snd_rawmidi_substream *substream)
{
    unsigned long flags;
    struct snd_gus_card *gus;

    gus = substream->rmidi->private_data;
    spin_lock_irqsave(&gus->uart_cmd_lock, flags);
    if (gus->gf1.interrupt_handler_midi_out != snd_gf1_interrupt_midi_out)
        snd_gf1_uart_reset(gus, 1);
    snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_MIDI_IN);
    gus->midi_substream_input = NULL;
    spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
    return 0;
}

static void snd_gf1_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
{
    struct snd_gus_card *gus;
    unsigned long flags;

    gus = substream->rmidi->private_data;

    spin_lock_irqsave(&gus->uart_cmd_lock, flags);
    if (up) {
        if ((gus->gf1.uart_cmd & 0x80) == 0)
            snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd | 0x80); /* enable Rx interrupts */
    } else {
        if (gus->gf1.uart_cmd & 0x80)
            snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x80); /* disable Rx interrupts */
    }
    spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
}

static void snd_gf1_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
{
    unsigned long flags;
    struct snd_gus_card *gus;
    char byte;
    int timeout;

    gus = substream->rmidi->private_data;

    spin_lock_irqsave(&gus->uart_cmd_lock, flags);
    if (up) {
        if ((gus->gf1.uart_cmd & 0x20) == 0) {
            spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
            /* wait for empty Rx - Tx is probably unlocked */
            timeout = 10000;
            while (timeout-- > 0 && snd_gf1_uart_stat(gus) & 0x01);
            /* Tx FIFO free? */
            spin_lock_irqsave(&gus->uart_cmd_lock, flags);
            if (gus->gf1.uart_cmd & 0x20) {
                spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
                return;
            }
            if (snd_gf1_uart_stat(gus) & 0x02) {
                if (snd_rawmidi_transmit(substream, &byte, 1) != 1) {
                    spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
                    return;
                }
                snd_gf1_uart_put(gus, byte);
            }
            snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd | 0x20);    /* enable Tx interrupt */
        }
    } else {
        if (gus->gf1.uart_cmd & 0x20)
            snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x20);
    }
    spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
}

static struct snd_rawmidi_ops snd_gf1_uart_output =
{
    .open =     snd_gf1_uart_output_open,
    .close =    snd_gf1_uart_output_close,
    .trigger =  snd_gf1_uart_output_trigger,
};

static struct snd_rawmidi_ops snd_gf1_uart_input =
{
    .open =     snd_gf1_uart_input_open,
    .close =    snd_gf1_uart_input_close,
    .trigger =  snd_gf1_uart_input_trigger,
};

int snd_gf1_rawmidi_new(struct snd_gus_card * gus, int device, struct snd_rawmidi ** rrawmidi)
{
    struct snd_rawmidi *rmidi;
    int err;

    if (rrawmidi)
        *rrawmidi = NULL;
    if ((err = snd_rawmidi_new(gus->card, "GF1", device, 1, 1, &rmidi)) < 0)
        return err;
    strcpy(rmidi->name, gus->interwave ? "AMD InterWave" : "GF1");
    snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_gf1_uart_output);
    snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_gf1_uart_input);
    rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT | SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
    rmidi->private_data = gus;
    gus->midi_uart = rmidi;
    if (rrawmidi)
        *rrawmidi = rmidi;
    return err;
}