linux/sound/oss/uart401.c
<<
>>
Prefs
   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
  32typedef 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}
  44uart401_devc;
  45
  46#define DATAPORT   (devc->base)
  47#define COMDPORT   (devc->base+1)
  48#define STATPORT   (devc->base+1)
  49
  50static 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
  58static void uart401_cmd(uart401_devc * devc, unsigned char cmd)
  59{
  60        outb((cmd), COMDPORT);
  61}
  62
  63static int uart401_read(uart401_devc * devc)
  64{
  65        return inb(DATAPORT);
  66}
  67
  68static 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
  79static int      reset_uart401(uart401_devc * devc);
  80static void     enter_uart_mode(uart401_devc * devc);
  81
  82static 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
  99irqreturn_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
 114static int
 115uart401_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
 138static 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
 146static 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
 183static inline int uart401_start_read(int dev)
 184{
 185        return 0;
 186}
 187
 188static inline int uart401_end_read(int dev)
 189{
 190        return 0;
 191}
 192
 193static inline void uart401_kick(int dev)
 194{
 195}
 196
 197static 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
 206static 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
 221static 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
 243static 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
 292int 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;
 382cleanup_midi_devs:
 383        kfree(midi_devs[devc->my_dev]);
 384cleanup_unload_mididev:
 385        sound_unload_mididev(devc->my_dev);
 386cleanup_irq:
 387        if (!devc->share_irq)
 388                free_irq(devc->irq, devc);
 389cleanup_devc:
 390        kfree(devc);
 391cleanup_region:
 392        release_region(hw_config->io_base, 4);
 393        return 0;
 394}
 395
 396void 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
 427EXPORT_SYMBOL(probe_uart401);
 428EXPORT_SYMBOL(unload_uart401);
 429EXPORT_SYMBOL(uart401intr);
 430
 431static struct address_info cfg_mpu;
 432
 433static int io = -1;
 434static int irq = -1;
 435
 436module_param(io, int, 0444);
 437module_param(irq, int, 0444);
 438
 439
 440static 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
 456static void __exit cleanup_uart401(void)
 457{
 458        if (cfg_mpu.io_base != -1 && cfg_mpu.irq != -1)
 459                unload_uart401(&cfg_mpu);
 460}
 461
 462module_init(init_uart401);
 463module_exit(cleanup_uart401);
 464
 465#ifndef MODULE
 466static 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
 481MODULE_LICENSE("GPL");
 482