LXR linux/sound/drivers/mpu401/mpu401

   1/*
   2 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   3 *  Routines for control of MPU-401 in UART mode
   4 *
   5 *  MPU-401 supports UART mode which is not capable generate transmit
   6 *  interrupts thus output is done via polling. Also, if irq < 0, then
   7 *  input is done also via polling. Do not expect good performance.
   8 *
   9 *
  10 *   This program is free software; you can redistribute it and/or modify
  11 *   it under the terms of the GNU General Public License as published by
  12 *   the Free Software Foundation; either version 2 of the License, or
  13 *   (at your option) any later version.
  14 *
  15 *   This program is distributed in the hope that it will be useful,
  16 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 *   GNU General Public License for more details.
  19 *
  20 *   You should have received a copy of the GNU General Public License
  21 *   along with this program; if not, write to the Free Software
  22 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  23 *
  24 *   13-03-2003:
  25 *      Added support for different kind of hardware I/O. Build in choices
  26 *      are port and mmio. For other kind of I/O, set mpu->read and
  27 *      mpu->write to your own I/O functions.
  28 *
  29 */
  30
  31#include <asm/io.h>
  32#include <linux/delay.h>
  33#include <linux/init.h>
  34#include <linux/slab.h>
  35#include <linux/ioport.h>
  36#include <linux/interrupt.h>
  37#include <linux/errno.h>
  38#include <sound/core.h>
  39#include <sound/mpu401.h>
  40
  41MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  42MODULE_DESCRIPTION("Routines for control of MPU-401 in UART mode");
  43MODULE_LICENSE("GPL");
  44
  45static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu);
  46static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu);
  47
  48/*
  49
  50 */
  51
  52#define snd_mpu401_input_avail(mpu) \
  53        (!(mpu->read(mpu, MPU401C(mpu)) & MPU401_RX_EMPTY))
  54#define snd_mpu401_output_ready(mpu) \
  55        (!(mpu->read(mpu, MPU401C(mpu)) & MPU401_TX_FULL))
  56
  57/* Build in lowlevel io */
  58static void mpu401_write_port(struct snd_mpu401 *mpu, unsigned char data,
  59                              unsigned long addr)
  60{
  61        outb(data, addr);
  62}
  63
  64static unsigned char mpu401_read_port(struct snd_mpu401 *mpu,
  65                                      unsigned long addr)
  66{
  67        return inb(addr);
  68}
  69
  70static void mpu401_write_mmio(struct snd_mpu401 *mpu, unsigned char data,
  71                              unsigned long addr)
  72{
  73        writeb(data, (void __iomem *)addr);
  74}
  75
  76static unsigned char mpu401_read_mmio(struct snd_mpu401 *mpu,
  77                                      unsigned long addr)
  78{
  79        return readb((void __iomem *)addr);
  80}
  81/*  */
  82
  83static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu)
  84{
  85        int timeout = 100000;
  86        for (; timeout > 0 && snd_mpu401_input_avail(mpu); timeout--)
  87                mpu->read(mpu, MPU401D(mpu));
  88#ifdef CONFIG_SND_DEBUG
  89        if (timeout <= 0)
  90                snd_printk(KERN_ERR "cmd: clear rx timeout (status = 0x%x)\n",
  91                           mpu->read(mpu, MPU401C(mpu)));
  92#endif
  93}
  94
  95static void uart_interrupt_tx(struct snd_mpu401 *mpu)
  96{
  97        unsigned long flags;
  98
  99        if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
 100            test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
 101                spin_lock_irqsave(&mpu->output_lock, flags);
 102                snd_mpu401_uart_output_write(mpu);
 103                spin_unlock_irqrestore(&mpu->output_lock, flags);
 104        }
 105}
 106
 107static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
 108{
 109        unsigned long flags;
 110
 111        if (mpu->info_flags & MPU401_INFO_INPUT) {
 112                spin_lock_irqsave(&mpu->input_lock, flags);
 113                if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
 114                        snd_mpu401_uart_input_read(mpu);
 115                else
 116                        snd_mpu401_uart_clear_rx(mpu);
 117                spin_unlock_irqrestore(&mpu->input_lock, flags);
 118        }
 119        if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
 120                /* ok. for better Tx performance try do some output
 121                   when input is done */
 122                uart_interrupt_tx(mpu);
 123}
 124
 125/**
 126 * snd_mpu401_uart_interrupt - generic MPU401-UART interrupt handler
 127 * @irq: the irq number
 128 * @dev_id: mpu401 instance
 129 *
 130 * Processes the interrupt for MPU401-UART i/o.
 131 */
 132irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id)
 133{
 134        struct snd_mpu401 *mpu = dev_id;
 135        
 136        if (mpu == NULL)
 137                return IRQ_NONE;
 138        _snd_mpu401_uart_interrupt(mpu);
 139        return IRQ_HANDLED;
 140}
 141
 142EXPORT_SYMBOL(snd_mpu401_uart_interrupt);
 143
 144/**
 145 * snd_mpu401_uart_interrupt_tx - generic MPU401-UART transmit irq handler
 146 * @irq: the irq number
 147 * @dev_id: mpu401 instance
 148 *
 149 * Processes the interrupt for MPU401-UART output.
 150 */
 151irqreturn_t snd_mpu401_uart_interrupt_tx(int irq, void *dev_id)
 152{
 153        struct snd_mpu401 *mpu = dev_id;
 154        
 155        if (mpu == NULL)
 156                return IRQ_NONE;
 157        uart_interrupt_tx(mpu);
 158        return IRQ_HANDLED;
 159}
 160
 161EXPORT_SYMBOL(snd_mpu401_uart_interrupt_tx);
 162
 163/*
 164 * timer callback
 165 * reprogram the timer and call the interrupt job
 166 */
 167static void snd_mpu401_uart_timer(unsigned long data)
 168{
 169        struct snd_mpu401 *mpu = (struct snd_mpu401 *)data;
 170        unsigned long flags;
 171
 172        spin_lock_irqsave(&mpu->timer_lock, flags);
 173        /*mpu->mode |= MPU401_MODE_TIMER;*/
 174        mpu->timer.expires = 1 + jiffies;
 175        add_timer(&mpu->timer);
 176        spin_unlock_irqrestore(&mpu->timer_lock, flags);
 177        if (mpu->rmidi)
 178                _snd_mpu401_uart_interrupt(mpu);
 179}
 180
 181/*
 182 * initialize the timer callback if not programmed yet
 183 */
 184static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input)
 185{
 186        unsigned long flags;
 187
 188        spin_lock_irqsave (&mpu->timer_lock, flags);
 189        if (mpu->timer_invoked == 0) {
 190                init_timer(&mpu->timer);
 191                mpu->timer.data = (unsigned long)mpu;
 192                mpu->timer.function = snd_mpu401_uart_timer;
 193                mpu->timer.expires = 1 + jiffies;
 194                add_timer(&mpu->timer);
 195        } 
 196        mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER :
 197                MPU401_MODE_OUTPUT_TIMER;
 198        spin_unlock_irqrestore (&mpu->timer_lock, flags);
 199}
 200
 201/*
 202 * remove the timer callback if still active
 203 */
 204static void snd_mpu401_uart_remove_timer (struct snd_mpu401 *mpu, int input)
 205{
 206        unsigned long flags;
 207
 208        spin_lock_irqsave (&mpu->timer_lock, flags);
 209        if (mpu->timer_invoked) {
 210                mpu->timer_invoked &= input ? ~MPU401_MODE_INPUT_TIMER :
 211                        ~MPU401_MODE_OUTPUT_TIMER;
 212                if (! mpu->timer_invoked)
 213                        del_timer(&mpu->timer);
 214        }
 215        spin_unlock_irqrestore (&mpu->timer_lock, flags);
 216}
 217
 218/*
 219 * send a UART command
 220 * return zero if successful, non-zero for some errors
 221 */
 222
 223static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd,
 224                               int ack)
 225{
 226        unsigned long flags;
 227        int timeout, ok;
 228
 229        spin_lock_irqsave(&mpu->input_lock, flags);
 230        if (mpu->hardware != MPU401_HW_TRID4DWAVE) {
 231                mpu->write(mpu, 0x00, MPU401D(mpu));
 232                /*snd_mpu401_uart_clear_rx(mpu);*/
 233        }
 234        /* ok. standard MPU-401 initialization */
 235        if (mpu->hardware != MPU401_HW_SB) {
 236                for (timeout = 1000; timeout > 0 &&
 237                             !snd_mpu401_output_ready(mpu); timeout--)
 238                        udelay(10);
 239#ifdef CONFIG_SND_DEBUG
 240                if (!timeout)
 241                        snd_printk(KERN_ERR "cmd: tx timeout (status = 0x%x)\n",
 242                                   mpu->read(mpu, MPU401C(mpu)));
 243#endif
 244        }
 245        mpu->write(mpu, cmd, MPU401C(mpu));
 246        if (ack && !(mpu->info_flags & MPU401_INFO_NO_ACK)) {
 247                ok = 0;
 248                timeout = 10000;
 249                while (!ok && timeout-- > 0) {
 250                        if (snd_mpu401_input_avail(mpu)) {
 251                                if (mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
 252                                        ok = 1;
 253                        }
 254                }
 255                if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
 256                        ok = 1;
 257        } else
 258                ok = 1;
 259        spin_unlock_irqrestore(&mpu->input_lock, flags);
 260        if (!ok) {
 261                snd_printk(KERN_ERR "cmd: 0x%x failed at 0x%lx "
 262                           "(status = 0x%x, data = 0x%x)\n", cmd, mpu->port,
 263                           mpu->read(mpu, MPU401C(mpu)),
 264                           mpu->read(mpu, MPU401D(mpu)));
 265                return 1;
 266        }
 267        return 0;
 268}
 269
 270static int snd_mpu401_do_reset(struct snd_mpu401 *mpu)
 271{
 272        if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
 273                return -EIO;
 274        if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 0))
 275                return -EIO;
 276        return 0;
 277}
 278
 279/*
 280 * input/output open/close - protected by open_mutex in rawmidi.c
 281 */
 282static int snd_mpu401_uart_input_open(struct snd_rawmidi_substream *substream)
 283{
 284        struct snd_mpu401 *mpu;
 285        int err;
 286
 287        mpu = substream->rmidi->private_data;
 288        if (mpu->open_input && (err = mpu->open_input(mpu)) < 0)
 289                return err;
 290        if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
 291                if (snd_mpu401_do_reset(mpu) < 0)
 292                        goto error_out;
 293        }
 294        mpu->substream_input = substream;
 295        set_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
 296        return 0;
 297
 298error_out:
 299        if (mpu->open_input && mpu->close_input)
 300                mpu->close_input(mpu);
 301        return -EIO;
 302}
 303
 304static int snd_mpu401_uart_output_open(struct snd_rawmidi_substream *substream)
 305{
 306        struct snd_mpu401 *mpu;
 307        int err;
 308
 309        mpu = substream->rmidi->private_data;
 310        if (mpu->open_output && (err = mpu->open_output(mpu)) < 0)
 311                return err;
 312        if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
 313                if (snd_mpu401_do_reset(mpu) < 0)
 314                        goto error_out;
 315        }
 316        mpu->substream_output = substream;
 317        set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
 318        return 0;
 319
 320error_out:
 321        if (mpu->open_output && mpu->close_output)
 322                mpu->close_output(mpu);
 323        return -EIO;
 324}
 325
 326static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream)
 327{
 328        struct snd_mpu401 *mpu;
 329        int err = 0;
 330
 331        mpu = substream->rmidi->private_data;
 332        clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
 333        mpu->substream_input = NULL;
 334        if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
 335                err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
 336        if (mpu->close_input)
 337                mpu->close_input(mpu);
 338        if (err)
 339                return -EIO;
 340        return 0;
 341}
 342
 343static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream)
 344{
 345        struct snd_mpu401 *mpu;
 346        int err = 0;
 347
 348        mpu = substream->rmidi->private_data;
 349        clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
 350        mpu->substream_output = NULL;
 351        if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
 352                err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
 353        if (mpu->close_output)
 354                mpu->close_output(mpu);
 355        if (err)
 356                return -EIO;
 357        return 0;
 358}
 359
 360/*
 361 * trigger input callback
 362 */
 363static void
 364snd_mpu401_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
 365{
 366        unsigned long flags;
 367        struct snd_mpu401 *mpu;
 368        int max = 64;
 369
 370        mpu = substream->rmidi->private_data;
 371        if (up) {
 372                if (! test_and_set_bit(MPU401_MODE_BIT_INPUT_TRIGGER,
 373                                       &mpu->mode)) {
 374                        /* first time - flush FIFO */
 375                        while (max-- > 0)
 376                                mpu->read(mpu, MPU401D(mpu));
 377                        if (mpu->irq < 0)
 378                                snd_mpu401_uart_add_timer(mpu, 1);
 379                }
 380                
 381                /* read data in advance */
 382                spin_lock_irqsave(&mpu->input_lock, flags);
 383                snd_mpu401_uart_input_read(mpu);
 384                spin_unlock_irqrestore(&mpu->input_lock, flags);
 385        } else {
 386                if (mpu->irq < 0)
 387                        snd_mpu401_uart_remove_timer(mpu, 1);
 388                clear_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
 389        }
 390
 391}
 392
 393/*
 394 * transfer input pending data
 395 * call with input_lock spinlock held
 396 */
 397static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu)
 398{
 399        int max = 128;
 400        unsigned char byte;
 401
 402        while (max-- > 0) {
 403                if (! snd_mpu401_input_avail(mpu))
 404                        break; /* input not available */
 405                byte = mpu->read(mpu, MPU401D(mpu));
 406                if (test_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
 407                        snd_rawmidi_receive(mpu->substream_input, &byte, 1);
 408        }
 409}
 410
 411/*
 412 *  Tx FIFO sizes:
 413 *    CS4237B                   - 16 bytes
 414 *    AudioDrive ES1688         - 12 bytes
 415 *    S3 SonicVibes             -  8 bytes
 416 *    SoundBlaster AWE 64       -  2 bytes (ugly hardware)
 417 */
 418
 419/*
 420 * write output pending bytes
 421 * call with output_lock spinlock held
 422 */
 423static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu)
 424{
 425        unsigned char byte;
 426        int max = 256;
 427
 428        do {
 429                if (snd_rawmidi_transmit_peek(mpu->substream_output,
 430                                              &byte, 1) == 1) {
 431                        /*
 432                         * Try twice because there is hardware that insists on
 433                         * setting the output busy bit after each write.
 434                         */
 435                        if (!snd_mpu401_output_ready(mpu) &&
 436                            !snd_mpu401_output_ready(mpu))
 437                                break;  /* Tx FIFO full - try again later */
 438                        mpu->write(mpu, byte, MPU401D(mpu));
 439                        snd_rawmidi_transmit_ack(mpu->substream_output, 1);
 440                } else {
 441                        snd_mpu401_uart_remove_timer (mpu, 0);
 442                        break;  /* no other data - leave the tx loop */
 443                }
 444        } while (--max > 0);
 445}
 446
 447/*
 448 * output trigger callback
 449 */
 450static void
 451snd_mpu401_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
 452{
 453        unsigned long flags;
 454        struct snd_mpu401 *mpu;
 455
 456        mpu = substream->rmidi->private_data;
 457        if (up) {
 458                set_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
 459
 460                /* try to add the timer at each output trigger,
 461                 * since the output timer might have been removed in
 462                 * snd_mpu401_uart_output_write().
 463                 */
 464                if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
 465                        snd_mpu401_uart_add_timer(mpu, 0);
 466
 467                /* output pending data */
 468                spin_lock_irqsave(&mpu->output_lock, flags);
 469                snd_mpu401_uart_output_write(mpu);
 470                spin_unlock_irqrestore(&mpu->output_lock, flags);
 471        } else {
 472                if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
 473                        snd_mpu401_uart_remove_timer(mpu, 0);
 474                clear_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
 475        }
 476}
 477
 478/*
 479
 480 */
 481
 482static struct snd_rawmidi_ops snd_mpu401_uart_output =
 483{
 484        .open =         snd_mpu401_uart_output_open,
 485        .close =        snd_mpu401_uart_output_close,
 486        .trigger =      snd_mpu401_uart_output_trigger,
 487};
 488
 489static struct snd_rawmidi_ops snd_mpu401_uart_input =
 490{
 491        .open =         snd_mpu401_uart_input_open,
 492        .close =        snd_mpu401_uart_input_close,
 493        .trigger =      snd_mpu401_uart_input_trigger,
 494};
 495
 496static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi)
 497{
 498        struct snd_mpu401 *mpu = rmidi->private_data;
 499        if (mpu->irq_flags && mpu->irq >= 0)
 500                free_irq(mpu->irq, (void *) mpu);
 501        release_and_free_resource(mpu->res);
 502        kfree(mpu);
 503}
 504
 505/**
 506 * snd_mpu401_uart_new - create an MPU401-UART instance
 507 * @card: the card instance
 508 * @device: the device index, zero-based
 509 * @hardware: the hardware type, MPU401_HW_XXXX
 510 * @port: the base address of MPU401 port
 511 * @info_flags: bitflags MPU401_INFO_XXX
 512 * @irq: the irq number, -1 if no interrupt for mpu
 513 * @irq_flags: the irq request flags (SA_XXX), 0 if irq was already reserved.
 514 * @rrawmidi: the pointer to store the new rawmidi instance
 515 *
 516 * Creates a new MPU-401 instance.
 517 *
 518 * Note that the rawmidi instance is returned on the rrawmidi argument,
 519 * not the mpu401 instance itself.  To access to the mpu401 instance,
 520 * cast from rawmidi->private_data (with struct snd_mpu401 magic-cast).
 521 *
 522 * Returns zero if successful, or a negative error code.
 523 */
 524int snd_mpu401_uart_new(struct snd_card *card, int device,
 525                        unsigned short hardware,
 526                        unsigned long port,
 527                        unsigned int info_flags,
 528                        int irq, int irq_flags,
 529                        struct snd_rawmidi ** rrawmidi)
 530{
 531        struct snd_mpu401 *mpu;
 532        struct snd_rawmidi *rmidi;
 533        int in_enable, out_enable;
 534        int err;
 535
 536        if (rrawmidi)
 537                *rrawmidi = NULL;
 538        if (! (info_flags & (MPU401_INFO_INPUT | MPU401_INFO_OUTPUT)))
 539                info_flags |= MPU401_INFO_INPUT | MPU401_INFO_OUTPUT;
 540        in_enable = (info_flags & MPU401_INFO_INPUT) ? 1 : 0;
 541        out_enable = (info_flags & MPU401_INFO_OUTPUT) ? 1 : 0;
 542        if ((err = snd_rawmidi_new(card, "MPU-401U", device,
 543                                   out_enable, in_enable, &rmidi)) < 0)
 544                return err;
 545        mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
 546        if (mpu == NULL) {
 547                snd_printk(KERN_ERR "mpu401_uart: cannot allocate\n");
 548                snd_device_free(card, rmidi);
 549                return -ENOMEM;
 550        }
 551        rmidi->private_data = mpu;
 552        rmidi->private_free = snd_mpu401_uart_free;
 553        spin_lock_init(&mpu->input_lock);
 554        spin_lock_init(&mpu->output_lock);
 555        spin_lock_init(&mpu->timer_lock);
 556        mpu->hardware = hardware;
 557        if (! (info_flags & MPU401_INFO_INTEGRATED)) {
 558                int res_size = hardware == MPU401_HW_PC98II ? 4 : 2;
 559                mpu->res = request_region(port, res_size, "MPU401 UART");
 560                if (mpu->res == NULL) {
 561                        snd_printk(KERN_ERR "mpu401_uart: "
 562                                   "unable to grab port 0x%lx size %d\n",
 563                                   port, res_size);
 564                        snd_device_free(card, rmidi);
 565                        return -EBUSY;
 566                }
 567        }
 568        if (info_flags & MPU401_INFO_MMIO) {
 569                mpu->write = mpu401_write_mmio;
 570                mpu->read = mpu401_read_mmio;
 571        } else {
 572                mpu->write = mpu401_write_port;
 573                mpu->read = mpu401_read_port;
 574        }
 575        mpu->port = port;
 576        if (hardware == MPU401_HW_PC98II)
 577                mpu->cport = port + 2;
 578        else
 579                mpu->cport = port + 1;
 580        if (irq >= 0 && irq_flags) {
 581                if (request_irq(irq, snd_mpu401_uart_interrupt, irq_flags,
 582                                "MPU401 UART", (void *) mpu)) {
 583                        snd_printk(KERN_ERR "mpu401_uart: "
 584                                   "unable to grab IRQ %d\n", irq);
 585                        snd_device_free(card, rmidi);
 586                        return -EBUSY;
 587                }
 588        }
 589        mpu->info_flags = info_flags;
 590        mpu->irq = irq;
 591        mpu->irq_flags = irq_flags;
 592        if (card->shortname[0])
 593                snprintf(rmidi->name, sizeof(rmidi->name), "%s MIDI",
 594                         card->shortname);
 595        else
 596                sprintf(rmidi->name, "MPU-401 MIDI %d-%d",card->number, device);
 597        if (out_enable) {
 598                snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 599                                    &snd_mpu401_uart_output);
 600                rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
 601        }
 602        if (in_enable) {
 603                snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 604                                    &snd_mpu401_uart_input);
 605                rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
 606                if (out_enable)
 607                        rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
 608        }
 609        mpu->rmidi = rmidi;
 610        if (rrawmidi)
 611                *rrawmidi = rmidi;
 612        return 0;
 613}
 614
 615EXPORT_SYMBOL(snd_mpu401_uart_new);
 616
 617/*
 618 *  INIT part
 619 */
 620
 621static int __init alsa_mpu401_uart_init(void)
 622{
 623        return 0;
 624}
 625
 626static void __exit alsa_mpu401_uart_exit(void)
 627{
 628}
 629
 630module_init(alsa_mpu401_uart_init)
 631module_exit(alsa_mpu401_uart_exit)
 632