sound/drivers/mpu401/mpu401_uart.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *  Routines for control of MPU-401 in UART mode
   5  *
   6  *  MPU-401 supports UART mode which is not capable generate transmit
   7  *  interrupts thus output is done via polling. Without interrupt,
   8  *  input is done also via polling. Do not expect good performance.
   9  *
  10  *   13-03-2003:
  11  *      Added support for different kind of hardware I/O. Build in choices
  12  *      are port and mmio. For other kind of I/O, set mpu->read and
  13  *      mpu->write to your own I/O functions.
  14  */
  15
  16 #include <linux/io.h>
  17 #include <linux/delay.h>
  18 #include <linux/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/ioport.h>
  21 #include <linux/module.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/errno.h>
  24 #include <sound/core.h>
  25 #include <sound/mpu401.h>
  26
  27 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  28 MODULE_DESCRIPTION("Routines for control of MPU-401 in UART mode");
  29 MODULE_LICENSE("GPL");
  30
  31 static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu);
  32 static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu);
  33
  34 /*
  35
  36  */
  37
  38 #define snd_mpu401_input_avail(mpu) \
  39         (!(mpu->read(mpu, MPU401C(mpu)) & MPU401_RX_EMPTY))
  40 #define snd_mpu401_output_ready(mpu) \
  41         (!(mpu->read(mpu, MPU401C(mpu)) & MPU401_TX_FULL))
  42
  43 /* Build in lowlevel io */
  44 static void mpu401_write_port(struct snd_mpu401 *mpu, unsigned char data,
  45                               unsigned long addr)
  46 {
  47         outb(data, addr);
  48 }
  49
  50 static unsigned char mpu401_read_port(struct snd_mpu401 *mpu,
  51                                       unsigned long addr)
  52 {
  53         return inb(addr);
  54 }
  55
  56 static void mpu401_write_mmio(struct snd_mpu401 *mpu, unsigned char data,
  57                               unsigned long addr)
  58 {
  59         writeb(data, (void __iomem *)addr);
  60 }
  61
  62 static unsigned char mpu401_read_mmio(struct snd_mpu401 *mpu,
  63                                       unsigned long addr)
  64 {
  65         return readb((void __iomem *)addr);
  66 }
  67 /*  */
  68
  69 static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu)
  70 {
  71         int timeout = 100000;
  72         for (; timeout > 0 && snd_mpu401_input_avail(mpu); timeout--)
  73                 mpu->read(mpu, MPU401D(mpu));
  74 #ifdef CONFIG_SND_DEBUG
  75         if (timeout <= 0)
  76                 dev_err(mpu->rmidi->dev,
  77                         "cmd: clear rx timeout (status = 0x%x)\n",
  78                         mpu->read(mpu, MPU401C(mpu)));
  79 #endif
  80 }
  81
  82 static void uart_interrupt_tx(struct snd_mpu401 *mpu)
  83 {
  84         unsigned long flags;
  85
  86         if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
  87             test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
  88                 spin_lock_irqsave(&mpu->output_lock, flags);
  89                 snd_mpu401_uart_output_write(mpu);
  90                 spin_unlock_irqrestore(&mpu->output_lock, flags);
  91         }
  92 }
  93
  94 static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
  95 {
  96         unsigned long flags;
  97
  98         if (mpu->info_flags & MPU401_INFO_INPUT) {
  99                 spin_lock_irqsave(&mpu->input_lock, flags);
 100                 if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
 101                         snd_mpu401_uart_input_read(mpu);
 102                 else
 103                         snd_mpu401_uart_clear_rx(mpu);
 104                 spin_unlock_irqrestore(&mpu->input_lock, flags);
 105         }
 106         if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
 107                 /* ok. for better Tx performance try do some output
 108                    when input is done */
 109                 uart_interrupt_tx(mpu);
 110 }
 111
 112 /**
 113  * snd_mpu401_uart_interrupt - generic MPU401-UART interrupt handler
 114  * @irq: the irq number
 115  * @dev_id: mpu401 instance
 116  *
 117  * Processes the interrupt for MPU401-UART i/o.
 118  *
 119  * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
 120  */
 121 irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id)
 122 {
 123         struct snd_mpu401 *mpu = dev_id;
 124
 125         if (!mpu)
 126                 return IRQ_NONE;
 127         _snd_mpu401_uart_interrupt(mpu);
 128         return IRQ_HANDLED;
 129 }
 130
 131 EXPORT_SYMBOL(snd_mpu401_uart_interrupt);
 132
 133 /**
 134  * snd_mpu401_uart_interrupt_tx - generic MPU401-UART transmit irq handler
 135  * @irq: the irq number
 136  * @dev_id: mpu401 instance
 137  *
 138  * Processes the interrupt for MPU401-UART output.
 139  *
 140  * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
 141  */
 142 irqreturn_t snd_mpu401_uart_interrupt_tx(int irq, void *dev_id)
 143 {
 144         struct snd_mpu401 *mpu = dev_id;
 145
 146         if (!mpu)
 147                 return IRQ_NONE;
 148         uart_interrupt_tx(mpu);
 149         return IRQ_HANDLED;
 150 }
 151
 152 EXPORT_SYMBOL(snd_mpu401_uart_interrupt_tx);
 153
 154 /*
 155  * timer callback
 156  * reprogram the timer and call the interrupt job
 157  */
 158 static void snd_mpu401_uart_timer(struct timer_list *t)
 159 {
 160         struct snd_mpu401 *mpu = from_timer(mpu, t, timer);
 161         unsigned long flags;
 162
 163         spin_lock_irqsave(&mpu->timer_lock, flags);
 164         /*mpu->mode |= MPU401_MODE_TIMER;*/
 165         mod_timer(&mpu->timer,  1 + jiffies);
 166         spin_unlock_irqrestore(&mpu->timer_lock, flags);
 167         if (mpu->rmidi)
 168                 _snd_mpu401_uart_interrupt(mpu);
 169 }
 170
 171 /*
 172  * initialize the timer callback if not programmed yet
 173  */
 174 static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input)
 175 {
 176         unsigned long flags;
 177
 178         spin_lock_irqsave (&mpu->timer_lock, flags);
 179         if (mpu->timer_invoked == 0) {
 180                 timer_setup(&mpu->timer, snd_mpu401_uart_timer, 0);
 181                 mod_timer(&mpu->timer, 1 + jiffies);
 182         }
 183         mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER :
 184                 MPU401_MODE_OUTPUT_TIMER;
 185         spin_unlock_irqrestore (&mpu->timer_lock, flags);
 186 }
 187
 188 /*
 189  * remove the timer callback if still active
 190  */
 191 static void snd_mpu401_uart_remove_timer (struct snd_mpu401 *mpu, int input)
 192 {
 193         unsigned long flags;
 194
 195         spin_lock_irqsave (&mpu->timer_lock, flags);
 196         if (mpu->timer_invoked) {
 197                 mpu->timer_invoked &= input ? ~MPU401_MODE_INPUT_TIMER :
 198                         ~MPU401_MODE_OUTPUT_TIMER;
 199                 if (! mpu->timer_invoked)
 200                         del_timer(&mpu->timer);
 201         }
 202         spin_unlock_irqrestore (&mpu->timer_lock, flags);
 203 }
 204
 205 /*
 206  * send a UART command
 207  * return zero if successful, non-zero for some errors
 208  */
 209
 210 static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd,
 211                                int ack)
 212 {
 213         unsigned long flags;
 214         int timeout, ok;
 215
 216         spin_lock_irqsave(&mpu->input_lock, flags);
 217         if (mpu->hardware != MPU401_HW_TRID4DWAVE) {
 218                 mpu->write(mpu, 0x00, MPU401D(mpu));
 219                 /*snd_mpu401_uart_clear_rx(mpu);*/
 220         }
 221         /* ok. standard MPU-401 initialization */
 222         if (mpu->hardware != MPU401_HW_SB) {
 223                 for (timeout = 1000; timeout > 0 &&
 224                              !snd_mpu401_output_ready(mpu); timeout--)
 225                         udelay(10);
 226 #ifdef CONFIG_SND_DEBUG
 227                 if (!timeout)
 228                         dev_err(mpu->rmidi->dev,
 229                                 "cmd: tx timeout (status = 0x%x)\n",
 230                                 mpu->read(mpu, MPU401C(mpu)));
 231 #endif
 232         }
 233         mpu->write(mpu, cmd, MPU401C(mpu));
 234         if (ack && !(mpu->info_flags & MPU401_INFO_NO_ACK)) {
 235                 ok = 0;
 236                 timeout = 10000;
 237                 while (!ok && timeout-- > 0) {
 238                         if (snd_mpu401_input_avail(mpu)) {
 239                                 if (mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
 240                                         ok = 1;
 241                         }
 242                 }
 243                 if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
 244                         ok = 1;
 245         } else
 246                 ok = 1;
 247         spin_unlock_irqrestore(&mpu->input_lock, flags);
 248         if (!ok) {
 249                 dev_err(mpu->rmidi->dev,
 250                         "cmd: 0x%x failed at 0x%lx (status = 0x%x, data = 0x%x)\n",
 251                         cmd, mpu->port,
 252                         mpu->read(mpu, MPU401C(mpu)),
 253                         mpu->read(mpu, MPU401D(mpu)));
 254                 return 1;
 255         }
 256         return 0;
 257 }
 258
 259 static int snd_mpu401_do_reset(struct snd_mpu401 *mpu)
 260 {
 261         if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
 262                 return -EIO;
 263         if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 0))
 264                 return -EIO;
 265         return 0;
 266 }
 267
 268 /*
 269  * input/output open/close - protected by open_mutex in rawmidi.c
 270  */
 271 static int snd_mpu401_uart_input_open(struct snd_rawmidi_substream *substream)
 272 {
 273         struct snd_mpu401 *mpu;
 274         int err;
 275
 276         mpu = substream->rmidi->private_data;
 277         if (mpu->open_input) {
 278                 err = mpu->open_input(mpu);
 279                 if (err < 0)
 280                         return err;
 281         }
 282         if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
 283                 if (snd_mpu401_do_reset(mpu) < 0)
 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) {
 303                 err = mpu->open_output(mpu);
 304                 if (err < 0)
 305                         return err;
 306         }
 307         if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
 308                 if (snd_mpu401_do_reset(mpu) < 0)
 309                         goto error_out;
 310         }
 311         mpu->substream_output = substream;
 312         set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
 313         return 0;
 314
 315 error_out:
 316         if (mpu->open_output && mpu->close_output)
 317                 mpu->close_output(mpu);
 318         return -EIO;
 319 }
 320
 321 static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream)
 322 {
 323         struct snd_mpu401 *mpu;
 324         int err = 0;
 325
 326         mpu = substream->rmidi->private_data;
 327         clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
 328         mpu->substream_input = NULL;
 329         if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
 330                 err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
 331         if (mpu->close_input)
 332                 mpu->close_input(mpu);
 333         if (err)
 334                 return -EIO;
 335         return 0;
 336 }
 337
 338 static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream)
 339 {
 340         struct snd_mpu401 *mpu;
 341         int err = 0;
 342
 343         mpu = substream->rmidi->private_data;
 344         clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
 345         mpu->substream_output = NULL;
 346         if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
 347                 err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
 348         if (mpu->close_output)
 349                 mpu->close_output(mpu);
 350         if (err)
 351                 return -EIO;
 352         return 0;
 353 }
 354
 355 /*
 356  * trigger input callback
 357  */
 358 static void
 359 snd_mpu401_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
 360 {
 361         unsigned long flags;
 362         struct snd_mpu401 *mpu;
 363         int max = 64;
 364
 365         mpu = substream->rmidi->private_data;
 366         if (up) {
 367                 if (! test_and_set_bit(MPU401_MODE_BIT_INPUT_TRIGGER,
 368                                        &mpu->mode)) {
 369                         /* first time - flush FIFO */
 370                         while (max-- > 0)
 371                                 mpu->read(mpu, MPU401D(mpu));
 372                         if (mpu->info_flags & MPU401_INFO_USE_TIMER)
 373                                 snd_mpu401_uart_add_timer(mpu, 1);
 374                 }
 375
 376                 /* read data in advance */
 377                 spin_lock_irqsave(&mpu->input_lock, flags);
 378                 snd_mpu401_uart_input_read(mpu);
 379                 spin_unlock_irqrestore(&mpu->input_lock, flags);
 380         } else {
 381                 if (mpu->info_flags & MPU401_INFO_USE_TIMER)
 382                         snd_mpu401_uart_remove_timer(mpu, 1);
 383                 clear_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
 384         }
 385
 386 }
 387
 388 /*
 389  * transfer input pending data
 390  * call with input_lock spinlock held
 391  */
 392 static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu)
 393 {
 394         int max = 128;
 395         unsigned char byte;
 396
 397         while (max-- > 0) {
 398                 if (! snd_mpu401_input_avail(mpu))
 399                         break; /* input not available */
 400                 byte = mpu->read(mpu, MPU401D(mpu));
 401                 if (test_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
 402                         snd_rawmidi_receive(mpu->substream_input, &byte, 1);
 403         }
 404 }
 405
 406 /*
 407  *  Tx FIFO sizes:
 408  *    CS4237B                   - 16 bytes
 409  *    AudioDrive ES1688         - 12 bytes
 410  *    S3 SonicVibes             -  8 bytes
 411  *    SoundBlaster AWE 64       -  2 bytes (ugly hardware)
 412  */
 413
 414 /*
 415  * write output pending bytes
 416  * call with output_lock spinlock held
 417  */
 418 static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu)
 419 {
 420         unsigned char byte;
 421         int max = 256;
 422
 423         do {
 424                 if (snd_rawmidi_transmit_peek(mpu->substream_output,
 425                                               &byte, 1) == 1) {
 426                         /*
 427                          * Try twice because there is hardware that insists on
 428                          * setting the output busy bit after each write.
 429                          */
 430                         if (!snd_mpu401_output_ready(mpu) &&
 431                             !snd_mpu401_output_ready(mpu))
 432                                 break;  /* Tx FIFO full - try again later */
 433                         mpu->write(mpu, byte, MPU401D(mpu));
 434                         snd_rawmidi_transmit_ack(mpu->substream_output, 1);
 435                 } else {
 436                         snd_mpu401_uart_remove_timer (mpu, 0);
 437                         break;  /* no other data - leave the tx loop */
 438                 }
 439         } while (--max > 0);
 440 }
 441
 442 /*
 443  * output trigger callback
 444  */
 445 static void
 446 snd_mpu401_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
 447 {
 448         unsigned long flags;
 449         struct snd_mpu401 *mpu;
 450
 451         mpu = substream->rmidi->private_data;
 452         if (up) {
 453                 set_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
 454
 455                 /* try to add the timer at each output trigger,
 456                  * since the output timer might have been removed in
 457                  * snd_mpu401_uart_output_write().
 458                  */
 459                 if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
 460                         snd_mpu401_uart_add_timer(mpu, 0);
 461
 462                 /* output pending data */
 463                 spin_lock_irqsave(&mpu->output_lock, flags);
 464                 snd_mpu401_uart_output_write(mpu);
 465                 spin_unlock_irqrestore(&mpu->output_lock, flags);
 466         } else {
 467                 if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
 468                         snd_mpu401_uart_remove_timer(mpu, 0);
 469                 clear_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
 470         }
 471 }
 472
 473 /*
 474
 475  */
 476
 477 static const struct snd_rawmidi_ops snd_mpu401_uart_output =
 478 {
 479         .open =         snd_mpu401_uart_output_open,
 480         .close =        snd_mpu401_uart_output_close,
 481         .trigger =      snd_mpu401_uart_output_trigger,
 482 };
 483
 484 static const struct snd_rawmidi_ops snd_mpu401_uart_input =
 485 {
 486         .open =         snd_mpu401_uart_input_open,
 487         .close =        snd_mpu401_uart_input_close,
 488         .trigger =      snd_mpu401_uart_input_trigger,
 489 };
 490
 491 static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi)
 492 {
 493         struct snd_mpu401 *mpu = rmidi->private_data;
 494         if (mpu->irq >= 0)
 495                 free_irq(mpu->irq, (void *) mpu);
 496         release_and_free_resource(mpu->res);
 497         kfree(mpu);
 498 }
 499
 500 /**
 501  * snd_mpu401_uart_new - create an MPU401-UART instance
 502  * @card: the card instance
 503  * @device: the device index, zero-based
 504  * @hardware: the hardware type, MPU401_HW_XXXX
 505  * @port: the base address of MPU401 port
 506  * @info_flags: bitflags MPU401_INFO_XXX
 507  * @irq: the ISA irq number, -1 if not to be allocated
 508  * @rrawmidi: the pointer to store the new rawmidi instance
 509  *
 510  * Creates a new MPU-401 instance.
 511  *
 512  * Note that the rawmidi instance is returned on the rrawmidi argument,
 513  * not the mpu401 instance itself.  To access to the mpu401 instance,
 514  * cast from rawmidi->private_data (with struct snd_mpu401 magic-cast).
 515  *
 516  * Return: Zero if successful, or a negative error code.
 517  */
 518 int snd_mpu401_uart_new(struct snd_card *card, int device,
 519                         unsigned short hardware,
 520                         unsigned long port,
 521                         unsigned int info_flags,
 522                         int irq,
 523                         struct snd_rawmidi ** rrawmidi)
 524 {
 525         struct snd_mpu401 *mpu;
 526         struct snd_rawmidi *rmidi;
 527         int in_enable, out_enable;
 528         int err;
 529
 530         if (rrawmidi)
 531                 *rrawmidi = NULL;
 532         if (! (info_flags & (MPU401_INFO_INPUT | MPU401_INFO_OUTPUT)))
 533                 info_flags |= MPU401_INFO_INPUT | MPU401_INFO_OUTPUT;
 534         in_enable = (info_flags & MPU401_INFO_INPUT) ? 1 : 0;
 535         out_enable = (info_flags & MPU401_INFO_OUTPUT) ? 1 : 0;
 536         err = snd_rawmidi_new(card, "MPU-401U", device,
 537                               out_enable, in_enable, &rmidi);
 538         if (err < 0)
 539                 return err;
 540         mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
 541         if (!mpu) {
 542                 err = -ENOMEM;
 543                 goto free_device;
 544         }
 545         rmidi->private_data = mpu;
 546         rmidi->private_free = snd_mpu401_uart_free;
 547         spin_lock_init(&mpu->input_lock);
 548         spin_lock_init(&mpu->output_lock);
 549         spin_lock_init(&mpu->timer_lock);
 550         mpu->hardware = hardware;
 551         mpu->irq = -1;
 552         mpu->rmidi = rmidi;
 553         if (! (info_flags & MPU401_INFO_INTEGRATED)) {
 554                 int res_size = hardware == MPU401_HW_PC98II ? 4 : 2;
 555                 mpu->res = request_region(port, res_size, "MPU401 UART");
 556                 if (!mpu->res) {
 557                         dev_err(rmidi->dev,
 558                                 "mpu401_uart: unable to grab port 0x%lx size %d\n",
 559                                 port, res_size);
 560                         err = -EBUSY;
 561                         goto free_device;
 562                 }
 563         }
 564         if (info_flags & MPU401_INFO_MMIO) {
 565                 mpu->write = mpu401_write_mmio;
 566                 mpu->read = mpu401_read_mmio;
 567         } else {
 568                 mpu->write = mpu401_write_port;
 569                 mpu->read = mpu401_read_port;
 570         }
 571         mpu->port = port;
 572         if (hardware == MPU401_HW_PC98II)
 573                 mpu->cport = port + 2;
 574         else
 575                 mpu->cport = port + 1;
 576         if (irq >= 0) {
 577                 if (request_irq(irq, snd_mpu401_uart_interrupt, 0,
 578                                 "MPU401 UART", (void *) mpu)) {
 579                         dev_err(rmidi->dev,
 580                                 "mpu401_uart: unable to grab IRQ %d\n", irq);
 581                         err = -EBUSY;
 582                         goto free_device;
 583                 }
 584         }
 585         if (irq < 0 && !(info_flags & MPU401_INFO_IRQ_HOOK))
 586                 info_flags |= MPU401_INFO_USE_TIMER;
 587         mpu->info_flags = info_flags;
 588         mpu->irq = irq;
 589         if (card->shortname[0])
 590                 snprintf(rmidi->name, sizeof(rmidi->name), "%s MIDI",
 591                          card->shortname);
 592         else
 593                 sprintf(rmidi->name, "MPU-401 MIDI %d-%d",card->number, device);
 594         if (out_enable) {
 595                 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 596                                     &snd_mpu401_uart_output);
 597                 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
 598         }
 599         if (in_enable) {
 600                 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 601                                     &snd_mpu401_uart_input);
 602                 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
 603                 if (out_enable)
 604                         rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
 605         }
 606         if (rrawmidi)
 607                 *rrawmidi = rmidi;
 608         return 0;
 609 free_device:
 610         snd_device_free(card, rmidi);
 611         return err;
 612 }
 613
 614 EXPORT_SYMBOL(snd_mpu401_uart_new);