sound/oss/uart401.c

   1 /*
   2  * sound/oss/uart401.c
   3  *
   4  * MPU-401 UART driver (formerly uart401_midi.c)
   5  *
   6  *
   7  * Copyright (C) by Hannu Savolainen 1993-1997
   8  *
   9  * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
  10  * Version 2 (June 1991). See the "COPYING" file distributed with this software
  11  * for more info.
  12  *
  13  * Changes:
  14  *      Alan Cox                Reformatted, removed sound_mem usage, use normal Linux
  15  *                              interrupt allocation. Protect against bogus unload
  16  *                              Fixed to allow IRQ > 15
  17  *      Christoph Hellwig       Adapted to module_init/module_exit
  18  *      Arnaldo C. de Melo      got rid of check_region
  19  *
  20  * Status:
  21  *              Untested
  22  */
  23
  24 #include <linux/init.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/spinlock.h>
  29 #include "sound_config.h"
  30
  31 #include "mpu401.h"
  32
  33 struct uart401_devc
  34 {
  35         int             base;
  36         int             irq;
  37         int            *osp;
  38         void            (*midi_input_intr) (int dev, unsigned char data);
  39         int             opened, disabled;
  40         volatile unsigned char input_byte;
  41         int             my_dev;
  42         int             share_irq;
  43         spinlock_t      lock;
  44 };
  45
  46 #define DATAPORT   (devc->base)
  47 #define COMDPORT   (devc->base+1)
  48 #define STATPORT   (devc->base+1)
  49
  50 static int uart401_status(struct uart401_devc *devc)
  51 {
  52         return inb(STATPORT);
  53 }
  54
  55 #define input_avail(devc) (!(uart401_status(devc)&INPUT_AVAIL))
  56 #define output_ready(devc)      (!(uart401_status(devc)&OUTPUT_READY))
  57
  58 static void uart401_cmd(struct uart401_devc *devc, unsigned char cmd)
  59 {
  60         outb((cmd), COMDPORT);
  61 }
  62
  63 static int uart401_read(struct uart401_devc *devc)
  64 {
  65         return inb(DATAPORT);
  66 }
  67
  68 static void uart401_write(struct uart401_devc *devc, unsigned char byte)
  69 {
  70         outb((byte), DATAPORT);
  71 }
  72
  73 #define OUTPUT_READY    0x40
  74 #define INPUT_AVAIL     0x80
  75 #define MPU_ACK         0xFE
  76 #define MPU_RESET       0xFF
  77 #define UART_MODE_ON    0x3F
  78
  79 static int      reset_uart401(struct uart401_devc *devc);
  80 static void     enter_uart_mode(struct uart401_devc *devc);
  81
  82 static void uart401_input_loop(struct uart401_devc *devc)
  83 {
  84         int work_limit=30000;
  85
  86         while (input_avail(devc) && --work_limit)
  87         {
  88                 unsigned char   c = uart401_read(devc);
  89
  90                 if (c == MPU_ACK)
  91                         devc->input_byte = c;
  92                 else if (devc->opened & OPEN_READ && devc->midi_input_intr)
  93                         devc->midi_input_intr(devc->my_dev, c);
  94         }
  95         if(work_limit==0)
  96                 printk(KERN_WARNING "Too much work in interrupt on uart401 (0x%X). UART jabbering ??\n", devc->base);
  97 }
  98
  99 irqreturn_t uart401intr(int irq, void *dev_id)
 100 {
 101         struct uart401_devc *devc = dev_id;
 102
 103         if (devc == NULL)
 104         {
 105                 printk(KERN_ERR "uart401: bad devc\n");
 106                 return IRQ_NONE;
 107         }
 108
 109         if (input_avail(devc))
 110                 uart401_input_loop(devc);
 111         return IRQ_HANDLED;
 112 }
 113
 114 static int
 115 uart401_open(int dev, int mode,
 116              void            (*input) (int dev, unsigned char data),
 117              void            (*output) (int dev)
 118 )
 119 {
 120         struct uart401_devc *devc = (struct uart401_devc *)
 121                                     midi_devs[dev]->devc;
 122
 123         if (devc->opened)
 124                 return -EBUSY;
 125
 126         /* Flush the UART */
 127
 128         while (input_avail(devc))
 129                 uart401_read(devc);
 130
 131         devc->midi_input_intr = input;
 132         devc->opened = mode;
 133         enter_uart_mode(devc);
 134         devc->disabled = 0;
 135
 136         return 0;
 137 }
 138
 139 static void uart401_close(int dev)
 140 {
 141         struct uart401_devc *devc = (struct uart401_devc *)
 142                                     midi_devs[dev]->devc;
 143
 144         reset_uart401(devc);
 145         devc->opened = 0;
 146 }
 147
 148 static int uart401_out(int dev, unsigned char midi_byte)
 149 {
 150         int timeout;
 151         unsigned long flags;
 152         struct uart401_devc *devc = (struct uart401_devc *)
 153                                     midi_devs[dev]->devc;
 154
 155         if (devc->disabled)
 156                 return 1;
 157         /*
 158          * Test for input since pending input seems to block the output.
 159          */
 160
 161         spin_lock_irqsave(&devc->lock,flags);
 162         if (input_avail(devc))
 163                 uart401_input_loop(devc);
 164
 165         spin_unlock_irqrestore(&devc->lock,flags);
 166
 167         /*
 168          * Sometimes it takes about 13000 loops before the output becomes ready
 169          * (After reset). Normally it takes just about 10 loops.
 170          */
 171
 172         for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
 173
 174         if (!output_ready(devc))
 175         {
 176                   printk(KERN_WARNING "uart401: Timeout - Device not responding\n");
 177                   devc->disabled = 1;
 178                   reset_uart401(devc);
 179                   enter_uart_mode(devc);
 180                   return 1;
 181         }
 182         uart401_write(devc, midi_byte);
 183         return 1;
 184 }
 185
 186 static inline int uart401_start_read(int dev)
 187 {
 188         return 0;
 189 }
 190
 191 static inline int uart401_end_read(int dev)
 192 {
 193         return 0;
 194 }
 195
 196 static inline void uart401_kick(int dev)
 197 {
 198 }
 199
 200 static inline int uart401_buffer_status(int dev)
 201 {
 202         return 0;
 203 }
 204
 205 #define MIDI_SYNTH_NAME "MPU-401 UART"
 206 #define MIDI_SYNTH_CAPS SYNTH_CAP_INPUT
 207 #include "midi_synth.h"
 208
 209 static const struct midi_operations uart401_operations =
 210 {
 211         .owner          = THIS_MODULE,
 212         .info           = {"MPU-401 (UART) MIDI", 0, 0, SNDCARD_MPU401},
 213         .converter      = &std_midi_synth,
 214         .in_info        = {0},
 215         .open           = uart401_open,
 216         .close          = uart401_close,
 217         .outputc        = uart401_out,
 218         .start_read     = uart401_start_read,
 219         .end_read       = uart401_end_read,
 220         .kick           = uart401_kick,
 221         .buffer_status  = uart401_buffer_status,
 222 };
 223
 224 static void enter_uart_mode(struct uart401_devc *devc)
 225 {
 226         int ok, timeout;
 227         unsigned long flags;
 228
 229         spin_lock_irqsave(&devc->lock,flags);
 230         for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
 231
 232         devc->input_byte = 0;
 233         uart401_cmd(devc, UART_MODE_ON);
 234
 235         ok = 0;
 236         for (timeout = 50000; timeout > 0 && !ok; timeout--)
 237                 if (devc->input_byte == MPU_ACK)
 238                         ok = 1;
 239                 else if (input_avail(devc))
 240                         if (uart401_read(devc) == MPU_ACK)
 241                                 ok = 1;
 242
 243         spin_unlock_irqrestore(&devc->lock,flags);
 244 }
 245
 246 static int reset_uart401(struct uart401_devc *devc)
 247 {
 248         int ok, timeout, n;
 249
 250         /*
 251          * Send the RESET command. Try again if no success at the first time.
 252          */
 253
 254         ok = 0;
 255
 256         for (n = 0; n < 2 && !ok; n++)
 257         {
 258                 for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
 259                 devc->input_byte = 0;
 260                 uart401_cmd(devc, MPU_RESET);
 261
 262                 /*
 263                  * Wait at least 25 msec. This method is not accurate so let's make the
 264                  * loop bit longer. Cannot sleep since this is called during boot.
 265                  */
 266
 267                 for (timeout = 50000; timeout > 0 && !ok; timeout--)
 268                 {
 269                         if (devc->input_byte == MPU_ACK)        /* Interrupt */
 270                                 ok = 1;
 271                         else if (input_avail(devc))
 272                         {
 273                                 if (uart401_read(devc) == MPU_ACK)
 274                                         ok = 1;
 275                         }
 276                 }
 277         }
 278
 279         /* Flush input before enabling interrupts */
 280         if (ok)
 281                 uart401_input_loop(devc);
 282         else
 283                 DDB(printk("Reset UART401 failed - No hardware detected.\n"));
 284
 285         return ok;
 286 }
 287
 288 int probe_uart401(struct address_info *hw_config, struct module *owner)
 289 {
 290         struct uart401_devc *devc;
 291         char *name = "MPU-401 (UART) MIDI";
 292         int ok = 0;
 293         unsigned long flags;
 294
 295         DDB(printk("Entered probe_uart401()\n"));
 296
 297         /* Default to "not found" */
 298         hw_config->slots[4] = -1;
 299
 300         if (!request_region(hw_config->io_base, 4, "MPU-401 UART")) {
 301                 printk(KERN_INFO "uart401: could not request_region(%d, 4)\n", hw_config->io_base);
 302                 return 0;
 303         }
 304
 305         devc = kmalloc(sizeof(struct uart401_devc), GFP_KERNEL);
 306         if (!devc) {
 307                 printk(KERN_WARNING "uart401: Can't allocate memory\n");
 308                 goto cleanup_region;
 309         }
 310
 311         devc->base = hw_config->io_base;
 312         devc->irq = hw_config->irq;
 313         devc->osp = hw_config->osp;
 314         devc->midi_input_intr = NULL;
 315         devc->opened = 0;
 316         devc->input_byte = 0;
 317         devc->my_dev = 0;
 318         devc->share_irq = 0;
 319         spin_lock_init(&devc->lock);
 320
 321         spin_lock_irqsave(&devc->lock,flags);
 322         ok = reset_uart401(devc);
 323         spin_unlock_irqrestore(&devc->lock,flags);
 324
 325         if (!ok)
 326                 goto cleanup_devc;
 327
 328         if (hw_config->name)
 329                 name = hw_config->name;
 330
 331         if (devc->irq < 0) {
 332                 devc->share_irq = 1;
 333                 devc->irq *= -1;
 334         } else
 335                 devc->share_irq = 0;
 336
 337         if (!devc->share_irq)
 338                 if (request_irq(devc->irq, uart401intr, 0, "MPU-401 UART", devc) < 0) {
 339                         printk(KERN_WARNING "uart401: Failed to allocate IRQ%d\n", devc->irq);
 340                         devc->share_irq = 1;
 341                 }
 342         devc->my_dev = sound_alloc_mididev();
 343         enter_uart_mode(devc);
 344
 345         if (devc->my_dev == -1) {
 346                 printk(KERN_INFO "uart401: Too many midi devices detected\n");
 347                 goto cleanup_irq;
 348         }
 349         conf_printf(name, hw_config);
 350         midi_devs[devc->my_dev] = kmemdup(&uart401_operations,
 351                                           sizeof(struct midi_operations),
 352                                           GFP_KERNEL);
 353         if (!midi_devs[devc->my_dev]) {
 354                 printk(KERN_ERR "uart401: Failed to allocate memory\n");
 355                 goto cleanup_unload_mididev;
 356         }
 357
 358         if (owner)
 359                 midi_devs[devc->my_dev]->owner = owner;
 360
 361         midi_devs[devc->my_dev]->devc = devc;
 362         midi_devs[devc->my_dev]->converter = kmemdup(&std_midi_synth,
 363                                                      sizeof(struct synth_operations),
 364                                                      GFP_KERNEL);
 365
 366         if (!midi_devs[devc->my_dev]->converter) {
 367                 printk(KERN_WARNING "uart401: Failed to allocate memory\n");
 368                 goto cleanup_midi_devs;
 369         }
 370         strcpy(midi_devs[devc->my_dev]->info.name, name);
 371         midi_devs[devc->my_dev]->converter->id = "UART401";
 372         midi_devs[devc->my_dev]->converter->midi_dev = devc->my_dev;
 373
 374         if (owner)
 375                 midi_devs[devc->my_dev]->converter->owner = owner;
 376
 377         hw_config->slots[4] = devc->my_dev;
 378         sequencer_init();
 379         devc->opened = 0;
 380         return 1;
 381 cleanup_midi_devs:
 382         kfree(midi_devs[devc->my_dev]);
 383 cleanup_unload_mididev:
 384         sound_unload_mididev(devc->my_dev);
 385 cleanup_irq:
 386         if (!devc->share_irq)
 387                 free_irq(devc->irq, devc);
 388 cleanup_devc:
 389         kfree(devc);
 390 cleanup_region:
 391         release_region(hw_config->io_base, 4);
 392         return 0;
 393 }
 394
 395 void unload_uart401(struct address_info *hw_config)
 396 {
 397         struct uart401_devc *devc;
 398         int n=hw_config->slots[4];
 399
 400         /* Not set up */
 401         if(n==-1 || midi_devs[n]==NULL)
 402                 return;
 403
 404         /* Not allocated (erm ??) */
 405
 406         devc = midi_devs[hw_config->slots[4]]->devc;
 407         if (devc == NULL)
 408                 return;
 409
 410         reset_uart401(devc);
 411         release_region(hw_config->io_base, 4);
 412
 413         if (!devc->share_irq)
 414                 free_irq(devc->irq, devc);
 415         kfree(midi_devs[devc->my_dev]->converter);
 416         kfree(midi_devs[devc->my_dev]);
 417         kfree(devc);
 418
 419         /* This kills midi_devs[x] */
 420         sound_unload_mididev(hw_config->slots[4]);
 421 }
 422
 423 EXPORT_SYMBOL(probe_uart401);
 424 EXPORT_SYMBOL(unload_uart401);
 425 EXPORT_SYMBOL(uart401intr);
 426
 427 static struct address_info cfg_mpu;
 428
 429 static int io = -1;
 430 static int irq = -1;
 431
 432 module_param(io, int, 0444);
 433 module_param(irq, int, 0444);
 434
 435
 436 static int __init init_uart401(void)
 437 {
 438         cfg_mpu.irq = irq;
 439         cfg_mpu.io_base = io;
 440
 441         /* Can be loaded either for module use or to provide functions
 442            to others */
 443         if (cfg_mpu.io_base != -1 && cfg_mpu.irq != -1) {
 444                 printk(KERN_INFO "MPU-401 UART driver Copyright (C) Hannu Savolainen 1993-1997");
 445                 if (!probe_uart401(&cfg_mpu, THIS_MODULE))
 446                         return -ENODEV;
 447         }
 448
 449         return 0;
 450 }
 451
 452 static void __exit cleanup_uart401(void)
 453 {
 454         if (cfg_mpu.io_base != -1 && cfg_mpu.irq != -1)
 455                 unload_uart401(&cfg_mpu);
 456 }
 457
 458 module_init(init_uart401);
 459 module_exit(cleanup_uart401);
 460
 461 #ifndef MODULE
 462 static int __init setup_uart401(char *str)
 463 {
 464         /* io, irq */
 465         int ints[3];
 466
 467         str = get_options(str, ARRAY_SIZE(ints), ints);
 468
 469         io = ints[1];
 470         irq = ints[2];
 471
 472         return 1;
 473 }
 474
 475 __setup("uart401=", setup_uart401);
 476 #endif
 477 MODULE_LICENSE("GPL");