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/spinlock.h>
  28 #include "sound_config.h"
  29
  30 #include "mpu401.h"
  31
  32 typedef struct uart401_devc
  33 {
  34         int             base;
  35         int             irq;
  36         int            *osp;
  37         void            (*midi_input_intr) (int dev, unsigned char data);
  38         int             opened, disabled;
  39         volatile unsigned char input_byte;
  40         int             my_dev;
  41         int             share_irq;
  42         spinlock_t      lock;
  43 }
  44 uart401_devc;
  45
  46 #define DATAPORT   (devc->base)
  47 #define COMDPORT   (devc->base+1)
  48 #define STATPORT   (devc->base+1)
  49
  50 static int uart401_status(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(uart401_devc * devc, unsigned char cmd)
  59 {
  60         outb((cmd), COMDPORT);
  61 }
  62
  63 static int uart401_read(uart401_devc * devc)
  64 {
  65         return inb(DATAPORT);
  66 }
  67
  68 static void uart401_write(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(uart401_devc * devc);
  80 static void     enter_uart_mode(uart401_devc * devc);
  81
  82 static void uart401_input_loop(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         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         uart401_devc *devc = (uart401_devc *) midi_devs[dev]->devc;
 121
 122         if (devc->opened)
 123                 return -EBUSY;
 124
 125         /* Flush the UART */
 126
 127         while (input_avail(devc))
 128                 uart401_read(devc);
 129
 130         devc->midi_input_intr = input;
 131         devc->opened = mode;
 132         enter_uart_mode(devc);
 133         devc->disabled = 0;
 134
 135         return 0;
 136 }
 137
 138 static void uart401_close(int dev)
 139 {
 140         uart401_devc *devc = (uart401_devc *) midi_devs[dev]->devc;
 141
 142         reset_uart401(devc);
 143         devc->opened = 0;
 144 }
 145
 146 static int uart401_out(int dev, unsigned char midi_byte)
 147 {
 148         int timeout;
 149         unsigned long flags;
 150         uart401_devc *devc = (uart401_devc *) midi_devs[dev]->devc;
 151
 152         if (devc->disabled)
 153                 return 1;
 154         /*
 155          * Test for input since pending input seems to block the output.
 156          */
 157
 158         spin_lock_irqsave(&devc->lock,flags);
 159         if (input_avail(devc))
 160                 uart401_input_loop(devc);
 161
 162         spin_unlock_irqrestore(&devc->lock,flags);
 163
 164         /*
 165          * Sometimes it takes about 13000 loops before the output becomes ready
 166          * (After reset). Normally it takes just about 10 loops.
 167          */
 168
 169         for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
 170
 171         if (!output_ready(devc))
 172         {
 173                   printk(KERN_WARNING "uart401: Timeout - Device not responding\n");
 174                   devc->disabled = 1;
 175                   reset_uart401(devc);
 176                   enter_uart_mode(devc);
 177                   return 1;
 178         }
 179         uart401_write(devc, midi_byte);
 180         return 1;
 181 }
 182
 183 static inline int uart401_start_read(int dev)
 184 {
 185         return 0;
 186 }
 187
 188 static inline int uart401_end_read(int dev)
 189 {
 190         return 0;
 191 }
 192
 193 static inline void uart401_kick(int dev)
 194 {
 195 }
 196
 197 static inline int uart401_buffer_status(int dev)
 198 {
 199         return 0;
 200 }
 201
 202 #define MIDI_SYNTH_NAME "MPU-401 UART"
 203 #define MIDI_SYNTH_CAPS SYNTH_CAP_INPUT
 204 #include "midi_synth.h"
 205
 206 static const struct midi_operations uart401_operations =
 207 {
 208         .owner          = THIS_MODULE,
 209         .info           = {"MPU-401 (UART) MIDI", 0, 0, SNDCARD_MPU401},
 210         .converter      = &std_midi_synth,
 211         .in_info        = {0},
 212         .open           = uart401_open,
 213         .close          = uart401_close,
 214         .outputc        = uart401_out,
 215         .start_read     = uart401_start_read,
 216         .end_read       = uart401_end_read,
 217         .kick           = uart401_kick,
 218         .buffer_status  = uart401_buffer_status,
 219 };
 220
 221 static void enter_uart_mode(uart401_devc * devc)
 222 {
 223         int ok, timeout;
 224         unsigned long flags;
 225
 226         spin_lock_irqsave(&devc->lock,flags);
 227         for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
 228
 229         devc->input_byte = 0;
 230         uart401_cmd(devc, UART_MODE_ON);
 231
 232         ok = 0;
 233         for (timeout = 50000; timeout > 0 && !ok; timeout--)
 234                 if (devc->input_byte == MPU_ACK)
 235                         ok = 1;
 236                 else if (input_avail(devc))
 237                         if (uart401_read(devc) == MPU_ACK)
 238                                 ok = 1;
 239
 240         spin_unlock_irqrestore(&devc->lock,flags);
 241 }
 242
 243 static int reset_uart401(uart401_devc * devc)
 244 {
 245         int ok, timeout, n;
 246
 247         /*
 248          * Send the RESET command. Try again if no success at the first time.
 249          */
 250
 251         ok = 0;
 252
 253         for (n = 0; n < 2 && !ok; n++)
 254         {
 255                 for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
 256                 devc->input_byte = 0;
 257                 uart401_cmd(devc, MPU_RESET);
 258
 259                 /*
 260                  * Wait at least 25 msec. This method is not accurate so let's make the
 261                  * loop bit longer. Cannot sleep since this is called during boot.
 262                  */
 263
 264                 for (timeout = 50000; timeout > 0 && !ok; timeout--)
 265                 {
 266                         if (devc->input_byte == MPU_ACK)        /* Interrupt */
 267                                 ok = 1;
 268                         else if (input_avail(devc))
 269                         {
 270                                 if (uart401_read(devc) == MPU_ACK)
 271                                         ok = 1;
 272                         }
 273                 }
 274         }
 275
 276
 277         if (ok)
 278         {
 279                 DEB(printk("Reset UART401 OK\n"));
 280         }
 281         else
 282                 DDB(printk("Reset UART401 failed - No hardware detected.\n"));
 283
 284         if (ok)
 285                 uart401_input_loop(devc);       /*
 286                                                  * Flush input before enabling interrupts
 287                                                  */
 288
 289         return ok;
 290 }
 291
 292 int probe_uart401(struct address_info *hw_config, struct module *owner)
 293 {
 294         uart401_devc *devc;
 295         char *name = "MPU-401 (UART) MIDI";
 296         int ok = 0;
 297         unsigned long flags;
 298
 299         DDB(printk("Entered probe_uart401()\n"));
 300
 301         /* Default to "not found" */
 302         hw_config->slots[4] = -1;
 303
 304         if (!request_region(hw_config->io_base, 4, "MPU-401 UART")) {
 305                 printk(KERN_INFO "uart401: could not request_region(%d, 4)\n", hw_config->io_base);
 306                 return 0;
 307         }
 308
 309         devc = kmalloc(sizeof(uart401_devc), GFP_KERNEL);
 310         if (!devc) {
 311                 printk(KERN_WARNING "uart401: Can't allocate memory\n");
 312                 goto cleanup_region;
 313         }
 314
 315         devc->base = hw_config->io_base;
 316         devc->irq = hw_config->irq;
 317         devc->osp = hw_config->osp;
 318         devc->midi_input_intr = NULL;
 319         devc->opened = 0;
 320         devc->input_byte = 0;
 321         devc->my_dev = 0;
 322         devc->share_irq = 0;
 323         spin_lock_init(&devc->lock);
 324
 325         spin_lock_irqsave(&devc->lock,flags);
 326         ok = reset_uart401(devc);
 327         spin_unlock_irqrestore(&devc->lock,flags);
 328
 329         if (!ok)
 330                 goto cleanup_devc;
 331
 332         if (hw_config->name)
 333                 name = hw_config->name;
 334
 335         if (devc->irq < 0) {
 336                 devc->share_irq = 1;
 337                 devc->irq *= -1;
 338         } else
 339                 devc->share_irq = 0;
 340
 341         if (!devc->share_irq)
 342                 if (request_irq(devc->irq, uart401intr, 0, "MPU-401 UART", devc) < 0) {
 343                         printk(KERN_WARNING "uart401: Failed to allocate IRQ%d\n", devc->irq);
 344                         devc->share_irq = 1;
 345                 }
 346         devc->my_dev = sound_alloc_mididev();
 347         enter_uart_mode(devc);
 348
 349         if (devc->my_dev == -1) {
 350                 printk(KERN_INFO "uart401: Too many midi devices detected\n");
 351                 goto cleanup_irq;
 352         }
 353         conf_printf(name, hw_config);
 354         midi_devs[devc->my_dev] = kmalloc(sizeof(struct midi_operations), GFP_KERNEL);
 355         if (!midi_devs[devc->my_dev]) {
 356                 printk(KERN_ERR "uart401: Failed to allocate memory\n");
 357                 goto cleanup_unload_mididev;
 358         }
 359         memcpy(midi_devs[devc->my_dev], &uart401_operations, sizeof(struct midi_operations));
 360
 361         if (owner)
 362                 midi_devs[devc->my_dev]->owner = owner;
 363
 364         midi_devs[devc->my_dev]->devc = devc;
 365         midi_devs[devc->my_dev]->converter = kmalloc(sizeof(struct synth_operations), GFP_KERNEL);
 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         memcpy(midi_devs[devc->my_dev]->converter, &std_midi_synth, sizeof(struct synth_operations));
 371         strcpy(midi_devs[devc->my_dev]->info.name, name);
 372         midi_devs[devc->my_dev]->converter->id = "UART401";
 373         midi_devs[devc->my_dev]->converter->midi_dev = devc->my_dev;
 374
 375         if (owner)
 376                 midi_devs[devc->my_dev]->converter->owner = owner;
 377
 378         hw_config->slots[4] = devc->my_dev;
 379         sequencer_init();
 380         devc->opened = 0;
 381         return 1;
 382 cleanup_midi_devs:
 383         kfree(midi_devs[devc->my_dev]);
 384 cleanup_unload_mididev:
 385         sound_unload_mididev(devc->my_dev);
 386 cleanup_irq:
 387         if (!devc->share_irq)
 388                 free_irq(devc->irq, devc);
 389 cleanup_devc:
 390         kfree(devc);
 391 cleanup_region:
 392         release_region(hw_config->io_base, 4);
 393         return 0;
 394 }
 395
 396 void unload_uart401(struct address_info *hw_config)
 397 {
 398         uart401_devc *devc;
 399         int n=hw_config->slots[4];
 400
 401         /* Not set up */
 402         if(n==-1 || midi_devs[n]==NULL)
 403                 return;
 404
 405         /* Not allocated (erm ??) */
 406
 407         devc = midi_devs[hw_config->slots[4]]->devc;
 408         if (devc == NULL)
 409                 return;
 410
 411         reset_uart401(devc);
 412         release_region(hw_config->io_base, 4);
 413
 414         if (!devc->share_irq)
 415                 free_irq(devc->irq, devc);
 416         if (devc)
 417         {
 418                 kfree(midi_devs[devc->my_dev]->converter);
 419                 kfree(midi_devs[devc->my_dev]);
 420                 kfree(devc);
 421                 devc = NULL;
 422         }
 423         /* This kills midi_devs[x] */
 424         sound_unload_mididev(hw_config->slots[4]);
 425 }
 426
 427 EXPORT_SYMBOL(probe_uart401);
 428 EXPORT_SYMBOL(unload_uart401);
 429 EXPORT_SYMBOL(uart401intr);
 430
 431 static struct address_info cfg_mpu;
 432
 433 static int io = -1;
 434 static int irq = -1;
 435
 436 module_param(io, int, 0444);
 437 module_param(irq, int, 0444);
 438
 439
 440 static int __init init_uart401(void)
 441 {
 442         cfg_mpu.irq = irq;
 443         cfg_mpu.io_base = io;
 444
 445         /* Can be loaded either for module use or to provide functions
 446            to others */
 447         if (cfg_mpu.io_base != -1 && cfg_mpu.irq != -1) {
 448                 printk(KERN_INFO "MPU-401 UART driver Copyright (C) Hannu Savolainen 1993-1997");
 449                 if (!probe_uart401(&cfg_mpu, THIS_MODULE))
 450                         return -ENODEV;
 451         }
 452
 453         return 0;
 454 }
 455
 456 static void __exit cleanup_uart401(void)
 457 {
 458         if (cfg_mpu.io_base != -1 && cfg_mpu.irq != -1)
 459                 unload_uart401(&cfg_mpu);
 460 }
 461
 462 module_init(init_uart401);
 463 module_exit(cleanup_uart401);
 464
 465 #ifndef MODULE
 466 static int __init setup_uart401(char *str)
 467 {
 468         /* io, irq */
 469         int ints[3];
 470
 471         str = get_options(str, ARRAY_SIZE(ints), ints);
 472
 473         io = ints[1];
 474         irq = ints[2];
 475
 476         return 1;
 477 }
 478
 479 __setup("uart401=", setup_uart401);
 480 #endif
 481 MODULE_LICENSE("GPL");