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