sound/drivers/mpu401/mpu401_uart.c

   1 /*
   2  *  Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
  32 #include <asm/io.h>
  33 #include <linux/delay.h>
  34 #include <linux/init.h>
  35 #include <linux/slab.h>
  36 #include <linux/ioport.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/errno.h>
  39 #include <sound/core.h>
  40 #include <sound/mpu401.h>
  41
  42 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>");
  43 MODULE_DESCRIPTION("Routines for control of MPU-401 in UART mode");
  44 MODULE_LICENSE("GPL");
  45
  46 static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu);
  47 static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu);
  48
  49 /*
  50
  51  */
  52
  53 #define snd_mpu401_input_avail(mpu)     (!(mpu->read(mpu, MPU401C(mpu)) & 0x80))
  54 #define snd_mpu401_output_ready(mpu)    (!(mpu->read(mpu, MPU401C(mpu)) & 0x40))
  55
  56 #define MPU401_RESET            0xff
  57 #define MPU401_ENTER_UART       0x3f
  58 #define MPU401_ACK              0xfe
  59
  60 /* Build in lowlevel io */
  61 static void mpu401_write_port(struct snd_mpu401 *mpu, unsigned char data,
  62                               unsigned long addr)
  63 {
  64         outb(data, addr);
  65 }
  66
  67 static unsigned char mpu401_read_port(struct snd_mpu401 *mpu,
  68                                       unsigned long addr)
  69 {
  70         return inb(addr);
  71 }
  72
  73 static void mpu401_write_mmio(struct snd_mpu401 *mpu, unsigned char data,
  74                               unsigned long addr)
  75 {
  76         writeb(data, (void __iomem *)addr);
  77 }
  78
  79 static unsigned char mpu401_read_mmio(struct snd_mpu401 *mpu,
  80                                       unsigned long addr)
  81 {
  82         return readb((void __iomem *)addr);
  83 }
  84 /*  */
  85
  86 static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu)
  87 {
  88         int timeout = 100000;
  89         for (; timeout > 0 && snd_mpu401_input_avail(mpu); timeout--)
  90                 mpu->read(mpu, MPU401D(mpu));
  91 #ifdef CONFIG_SND_DEBUG
  92         if (timeout <= 0)
  93                 snd_printk(KERN_ERR "cmd: clear rx timeout (status = 0x%x)\n",
  94                            mpu->read(mpu, MPU401C(mpu)));
  95 #endif
  96 }
  97
  98 static void uart_interrupt_tx(struct snd_mpu401 *mpu)
  99 {
 100         if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
 101             test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
 102                 spin_lock(&mpu->output_lock);
 103                 snd_mpu401_uart_output_write(mpu);
 104                 spin_unlock(&mpu->output_lock);
 105         }
 106 }
 107
 108 static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
 109 {
 110         if (mpu->info_flags & MPU401_INFO_INPUT) {
 111                 spin_lock(&mpu->input_lock);
 112                 if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
 113                         snd_mpu401_uart_input_read(mpu);
 114                 else
 115                         snd_mpu401_uart_clear_rx(mpu);
 116                 spin_unlock(&mpu->input_lock);
 117         }
 118         if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
 119                 /* ok. for better Tx performance try do some output
 120                    when input is done */
 121                 uart_interrupt_tx(mpu);
 122 }
 123
 124 /**
 125  * snd_mpu401_uart_interrupt - generic MPU401-UART interrupt handler
 126  * @irq: the irq number
 127  * @dev_id: mpu401 instance
 128  *
 129  * Processes the interrupt for MPU401-UART i/o.
 130  */
 131 irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id)
 132 {
 133         struct snd_mpu401 *mpu = dev_id;
 134
 135         if (mpu == NULL)
 136                 return IRQ_NONE;
 137         _snd_mpu401_uart_interrupt(mpu);
 138         return IRQ_HANDLED;
 139 }
 140
 141 EXPORT_SYMBOL(snd_mpu401_uart_interrupt);
 142
 143 /**
 144  * snd_mpu401_uart_interrupt_tx - generic MPU401-UART transmit irq handler
 145  * @irq: the irq number
 146  * @dev_id: mpu401 instance
 147  *
 148  * Processes the interrupt for MPU401-UART output.
 149  */
 150 irqreturn_t snd_mpu401_uart_interrupt_tx(int irq, void *dev_id)
 151 {
 152         struct snd_mpu401 *mpu = dev_id;
 153
 154         if (mpu == NULL)
 155                 return IRQ_NONE;
 156         uart_interrupt_tx(mpu);
 157         return IRQ_HANDLED;
 158 }
 159
 160 EXPORT_SYMBOL(snd_mpu401_uart_interrupt_tx);
 161
 162 /*
 163  * timer callback
 164  * reprogram the timer and call the interrupt job
 165  */
 166 static void snd_mpu401_uart_timer(unsigned long data)
 167 {
 168         struct snd_mpu401 *mpu = (struct snd_mpu401 *)data;
 169         unsigned long flags;
 170
 171         spin_lock_irqsave(&mpu->timer_lock, flags);
 172         /*mpu->mode |= MPU401_MODE_TIMER;*/
 173         mpu->timer.expires = 1 + jiffies;
 174         add_timer(&mpu->timer);
 175         spin_unlock_irqrestore(&mpu->timer_lock, flags);
 176         if (mpu->rmidi)
 177                 _snd_mpu401_uart_interrupt(mpu);
 178 }
 179
 180 /*
 181  * initialize the timer callback if not programmed yet
 182  */
 183 static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input)
 184 {
 185         unsigned long flags;
 186
 187         spin_lock_irqsave (&mpu->timer_lock, flags);
 188         if (mpu->timer_invoked == 0) {
 189                 init_timer(&mpu->timer);
 190                 mpu->timer.data = (unsigned long)mpu;
 191                 mpu->timer.function = snd_mpu401_uart_timer;
 192                 mpu->timer.expires = 1 + jiffies;
 193                 add_timer(&mpu->timer);
 194         }
 195         mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER :
 196                 MPU401_MODE_OUTPUT_TIMER;
 197         spin_unlock_irqrestore (&mpu->timer_lock, flags);
 198 }
 199
 200 /*
 201  * remove the timer callback if still active
 202  */
 203 static void snd_mpu401_uart_remove_timer (struct snd_mpu401 *mpu, int input)
 204 {
 205         unsigned long flags;
 206
 207         spin_lock_irqsave (&mpu->timer_lock, flags);
 208         if (mpu->timer_invoked) {
 209                 mpu->timer_invoked &= input ? ~MPU401_MODE_INPUT_TIMER :
 210                         ~MPU401_MODE_OUTPUT_TIMER;
 211                 if (! mpu->timer_invoked)
 212                         del_timer(&mpu->timer);
 213         }
 214         spin_unlock_irqrestore (&mpu->timer_lock, flags);
 215 }
 216
 217 /*
 218  * send a UART command
 219  * return zero if successful, non-zero for some errors
 220  */
 221
 222 static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd,
 223                                int ack)
 224 {
 225         unsigned long flags;
 226         int timeout, ok;
 227
 228         spin_lock_irqsave(&mpu->input_lock, flags);
 229         if (mpu->hardware != MPU401_HW_TRID4DWAVE) {
 230                 mpu->write(mpu, 0x00, MPU401D(mpu));
 231                 /*snd_mpu401_uart_clear_rx(mpu);*/
 232         }
 233         /* ok. standard MPU-401 initialization */
 234         if (mpu->hardware != MPU401_HW_SB) {
 235                 for (timeout = 1000; timeout > 0 &&
 236                              !snd_mpu401_output_ready(mpu); timeout--)
 237                         udelay(10);
 238 #ifdef CONFIG_SND_DEBUG
 239                 if (!timeout)
 240                         snd_printk(KERN_ERR "cmd: tx timeout (status = 0x%x)\n",
 241                                    mpu->read(mpu, MPU401C(mpu)));
 242 #endif
 243         }
 244         mpu->write(mpu, cmd, MPU401C(mpu));
 245         if (ack) {
 246                 ok = 0;
 247                 timeout = 10000;
 248                 while (!ok && timeout-- > 0) {
 249                         if (snd_mpu401_input_avail(mpu)) {
 250                                 if (mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
 251                                         ok = 1;
 252                         }
 253                 }
 254                 if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
 255                         ok = 1;
 256         } else
 257                 ok = 1;
 258         spin_unlock_irqrestore(&mpu->input_lock, flags);
 259         if (!ok) {
 260                 snd_printk(KERN_ERR "cmd: 0x%x failed at 0x%lx "
 261                            "(status = 0x%x, data = 0x%x)\n", cmd, mpu->port,
 262                            mpu->read(mpu, MPU401C(mpu)),
 263                            mpu->read(mpu, MPU401D(mpu)));
 264                 return 1;
 265         }
 266         return 0;
 267 }
 268
 269 /*
 270  * input/output open/close - protected by open_mutex in rawmidi.c
 271  */
 272 static int snd_mpu401_uart_input_open(struct snd_rawmidi_substream *substream)
 273 {
 274         struct snd_mpu401 *mpu;
 275         int err;
 276
 277         mpu = substream->rmidi->private_data;
 278         if (mpu->open_input && (err = mpu->open_input(mpu)) < 0)
 279                 return err;
 280         if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
 281                 if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
 282                         goto error_out;
 283                 if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1))
 284                         goto error_out;
 285         }
 286         mpu->substream_input = substream;
 287         set_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
 288         return 0;
 289
 290 error_out:
 291         if (mpu->open_input && mpu->close_input)
 292                 mpu->close_input(mpu);
 293         return -EIO;
 294 }
 295
 296 static int snd_mpu401_uart_output_open(struct snd_rawmidi_substream *substream)
 297 {
 298         struct snd_mpu401 *mpu;
 299         int err;
 300
 301         mpu = substream->rmidi->private_data;
 302         if (mpu->open_output && (err = mpu->open_output(mpu)) < 0)
 303                 return err;
 304         if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
 305                 if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
 306                         goto error_out;
 307                 if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1))
 308                         goto error_out;
 309         }
 310         mpu->substream_output = substream;
 311         set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
 312         return 0;
 313
 314 error_out:
 315         if (mpu->open_output && mpu->close_output)
 316                 mpu->close_output(mpu);
 317         return -EIO;
 318 }
 319
 320 static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream)
 321 {
 322         struct snd_mpu401 *mpu;
 323         int err = 0;
 324
 325         mpu = substream->rmidi->private_data;
 326         clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
 327         mpu->substream_input = NULL;
 328         if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
 329                 err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
 330         if (mpu->close_input)
 331                 mpu->close_input(mpu);
 332         if (err)
 333                 return -EIO;
 334         return 0;
 335 }
 336
 337 static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream)
 338 {
 339         struct snd_mpu401 *mpu;
 340         int err = 0;
 341
 342         mpu = substream->rmidi->private_data;
 343         clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
 344         mpu->substream_output = NULL;
 345         if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
 346                 err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
 347         if (mpu->close_output)
 348                 mpu->close_output(mpu);
 349         if (err)
 350                 return -EIO;
 351         return 0;
 352 }
 353
 354 /*
 355  * trigger input callback
 356  */
 357 static void
 358 snd_mpu401_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
 359 {
 360         unsigned long flags;
 361         struct snd_mpu401 *mpu;
 362         int max = 64;
 363
 364         mpu = substream->rmidi->private_data;
 365         if (up) {
 366                 if (! test_and_set_bit(MPU401_MODE_BIT_INPUT_TRIGGER,
 367                                        &mpu->mode)) {
 368                         /* first time - flush FIFO */
 369                         while (max-- > 0)
 370                                 mpu->read(mpu, MPU401D(mpu));
 371                         if (mpu->irq < 0)
 372                                 snd_mpu401_uart_add_timer(mpu, 1);
 373                 }
 374
 375                 /* read data in advance */
 376                 spin_lock_irqsave(&mpu->input_lock, flags);
 377                 snd_mpu401_uart_input_read(mpu);
 378                 spin_unlock_irqrestore(&mpu->input_lock, flags);
 379         } else {
 380                 if (mpu->irq < 0)
 381                         snd_mpu401_uart_remove_timer(mpu, 1);
 382                 clear_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
 383         }
 384
 385 }
 386
 387 /*
 388  * transfer input pending data
 389  * call with input_lock spinlock held
 390  */
 391 static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu)
 392 {
 393         int max = 128;
 394         unsigned char byte;
 395
 396         while (max-- > 0) {
 397                 if (! snd_mpu401_input_avail(mpu))
 398                         break; /* input not available */
 399                 byte = mpu->read(mpu, MPU401D(mpu));
 400                 if (test_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
 401                         snd_rawmidi_receive(mpu->substream_input, &byte, 1);
 402         }
 403 }
 404
 405 /*
 406  *  Tx FIFO sizes:
 407  *    CS4237B                   - 16 bytes
 408  *    AudioDrive ES1688         - 12 bytes
 409  *    S3 SonicVibes             -  8 bytes
 410  *    SoundBlaster AWE 64       -  2 bytes (ugly hardware)
 411  */
 412
 413 /*
 414  * write output pending bytes
 415  * call with output_lock spinlock held
 416  */
 417 static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu)
 418 {
 419         unsigned char byte;
 420         int max = 256, timeout;
 421
 422         do {
 423                 if (snd_rawmidi_transmit_peek(mpu->substream_output,
 424                                               &byte, 1) == 1) {
 425                         for (timeout = 100; timeout > 0; timeout--) {
 426                                 if (snd_mpu401_output_ready(mpu))
 427                                         break;
 428                         }
 429                         if (timeout == 0)
 430                                 break;  /* Tx FIFO full - try again later */
 431                         mpu->write(mpu, byte, MPU401D(mpu));
 432                         snd_rawmidi_transmit_ack(mpu->substream_output, 1);
 433                 } else {
 434                         snd_mpu401_uart_remove_timer (mpu, 0);
 435                         break;  /* no other data - leave the tx loop */
 436                 }
 437         } while (--max > 0);
 438 }
 439
 440 /*
 441  * output trigger callback
 442  */
 443 static void
 444 snd_mpu401_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
 445 {
 446         unsigned long flags;
 447         struct snd_mpu401 *mpu;
 448
 449         mpu = substream->rmidi->private_data;
 450         if (up) {
 451                 set_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
 452
 453                 /* try to add the timer at each output trigger,
 454                  * since the output timer might have been removed in
 455                  * snd_mpu401_uart_output_write().
 456                  */
 457                 if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
 458                         snd_mpu401_uart_add_timer(mpu, 0);
 459
 460                 /* output pending data */
 461                 spin_lock_irqsave(&mpu->output_lock, flags);
 462                 snd_mpu401_uart_output_write(mpu);
 463                 spin_unlock_irqrestore(&mpu->output_lock, flags);
 464         } else {
 465                 if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
 466                         snd_mpu401_uart_remove_timer(mpu, 0);
 467                 clear_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
 468         }
 469 }
 470
 471 /*
 472
 473  */
 474
 475 static struct snd_rawmidi_ops snd_mpu401_uart_output =
 476 {
 477         .open =         snd_mpu401_uart_output_open,
 478         .close =        snd_mpu401_uart_output_close,
 479         .trigger =      snd_mpu401_uart_output_trigger,
 480 };
 481
 482 static struct snd_rawmidi_ops snd_mpu401_uart_input =
 483 {
 484         .open =         snd_mpu401_uart_input_open,
 485         .close =        snd_mpu401_uart_input_close,
 486         .trigger =      snd_mpu401_uart_input_trigger,
 487 };
 488
 489 static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi)
 490 {
 491         struct snd_mpu401 *mpu = rmidi->private_data;
 492         if (mpu->irq_flags && mpu->irq >= 0)
 493                 free_irq(mpu->irq, (void *) mpu);
 494         release_and_free_resource(mpu->res);
 495         kfree(mpu);
 496 }
 497
 498 /**
 499  * snd_mpu401_uart_new - create an MPU401-UART instance
 500  * @card: the card instance
 501  * @device: the device index, zero-based
 502  * @hardware: the hardware type, MPU401_HW_XXXX
 503  * @port: the base address of MPU401 port
 504  * @info_flags: bitflags MPU401_INFO_XXX
 505  * @irq: the irq number, -1 if no interrupt for mpu
 506  * @irq_flags: the irq request flags (SA_XXX), 0 if irq was already reserved.
 507  * @rrawmidi: the pointer to store the new rawmidi instance
 508  *
 509  * Creates a new MPU-401 instance.
 510  *
 511  * Note that the rawmidi instance is returned on the rrawmidi argument,
 512  * not the mpu401 instance itself.  To access to the mpu401 instance,
 513  * cast from rawmidi->private_data (with struct snd_mpu401 magic-cast).
 514  *
 515  * Returns zero if successful, or a negative error code.
 516  */
 517 int snd_mpu401_uart_new(struct snd_card *card, int device,
 518                         unsigned short hardware,
 519                         unsigned long port,
 520                         unsigned int info_flags,
 521                         int irq, int irq_flags,
 522                         struct snd_rawmidi ** rrawmidi)
 523 {
 524         struct snd_mpu401 *mpu;
 525         struct snd_rawmidi *rmidi;
 526         int in_enable, out_enable;
 527         int err;
 528
 529         if (rrawmidi)
 530                 *rrawmidi = NULL;
 531         if (! (info_flags & (MPU401_INFO_INPUT | MPU401_INFO_OUTPUT)))
 532                 info_flags |= MPU401_INFO_INPUT | MPU401_INFO_OUTPUT;
 533         in_enable = (info_flags & MPU401_INFO_INPUT) ? 1 : 0;
 534         out_enable = (info_flags & MPU401_INFO_OUTPUT) ? 1 : 0;
 535         if ((err = snd_rawmidi_new(card, "MPU-401U", device,
 536                                    out_enable, in_enable, &rmidi)) < 0)
 537                 return err;
 538         mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
 539         if (mpu == NULL) {
 540                 snd_printk(KERN_ERR "mpu401_uart: cannot allocate\n");
 541                 snd_device_free(card, rmidi);
 542                 return -ENOMEM;
 543         }
 544         rmidi->private_data = mpu;
 545         rmidi->private_free = snd_mpu401_uart_free;
 546         spin_lock_init(&mpu->input_lock);
 547         spin_lock_init(&mpu->output_lock);
 548         spin_lock_init(&mpu->timer_lock);
 549         mpu->hardware = hardware;
 550         if (! (info_flags & MPU401_INFO_INTEGRATED)) {
 551                 int res_size = hardware == MPU401_HW_PC98II ? 4 : 2;
 552                 mpu->res = request_region(port, res_size, "MPU401 UART");
 553                 if (mpu->res == NULL) {
 554                         snd_printk(KERN_ERR "mpu401_uart: "
 555                                    "unable to grab port 0x%lx size %d\n",
 556                                    port, res_size);
 557                         snd_device_free(card, rmidi);
 558                         return -EBUSY;
 559                 }
 560         }
 561         if (info_flags & MPU401_INFO_MMIO) {
 562                 mpu->write = mpu401_write_mmio;
 563                 mpu->read = mpu401_read_mmio;
 564         } else {
 565                 mpu->write = mpu401_write_port;
 566                 mpu->read = mpu401_read_port;
 567         }
 568         mpu->port = port;
 569         if (hardware == MPU401_HW_PC98II)
 570                 mpu->cport = port + 2;
 571         else
 572                 mpu->cport = port + 1;
 573         if (irq >= 0 && irq_flags) {
 574                 if (request_irq(irq, snd_mpu401_uart_interrupt, irq_flags,
 575                                 "MPU401 UART", (void *) mpu)) {
 576                         snd_printk(KERN_ERR "mpu401_uart: "
 577                                    "unable to grab IRQ %d\n", irq);
 578                         snd_device_free(card, rmidi);
 579                         return -EBUSY;
 580                 }
 581         }
 582         mpu->info_flags = info_flags;
 583         mpu->irq = irq;
 584         mpu->irq_flags = irq_flags;
 585         if (card->shortname[0])
 586                 snprintf(rmidi->name, sizeof(rmidi->name), "%s MIDI",
 587                          card->shortname);
 588         else
 589                 sprintf(rmidi->name, "MPU-401 MIDI %d-%d",card->number, device);
 590         if (out_enable) {
 591                 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 592                                     &snd_mpu401_uart_output);
 593                 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
 594         }
 595         if (in_enable) {
 596                 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 597                                     &snd_mpu401_uart_input);
 598                 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
 599                 if (out_enable)
 600                         rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
 601         }
 602         mpu->rmidi = rmidi;
 603         if (rrawmidi)
 604                 *rrawmidi = rmidi;
 605         return 0;
 606 }
 607
 608 EXPORT_SYMBOL(snd_mpu401_uart_new);
 609
 610 /*
 611  *  INIT part
 612  */
 613
 614 static int __init alsa_mpu401_uart_init(void)
 615 {
 616         return 0;
 617 }
 618
 619 static void __exit alsa_mpu401_uart_exit(void)
 620 {
 621 }
 622
 623 module_init(alsa_mpu401_uart_init)
 624 module_exit(alsa_mpu401_uart_exit)