Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * sound/midibuf.c |
| 3 | * |
| 4 | * Device file manager for /dev/midi# |
| 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 | /* |
| 14 | * Thomas Sailer : ioctl code reworked (vmalloc/vfree removed) |
| 15 | */ |
| 16 | #include <linux/stddef.h> |
| 17 | #include <linux/kmod.h> |
| 18 | #include <linux/spinlock.h> |
| 19 | #define MIDIBUF_C |
| 20 | |
| 21 | #include "sound_config.h" |
| 22 | |
| 23 | |
| 24 | /* |
| 25 | * Don't make MAX_QUEUE_SIZE larger than 4000 |
| 26 | */ |
| 27 | |
| 28 | #define MAX_QUEUE_SIZE 4000 |
| 29 | |
| 30 | static wait_queue_head_t midi_sleeper[MAX_MIDI_DEV]; |
| 31 | static wait_queue_head_t input_sleeper[MAX_MIDI_DEV]; |
| 32 | |
| 33 | struct midi_buf |
| 34 | { |
| 35 | int len, head, tail; |
| 36 | unsigned char queue[MAX_QUEUE_SIZE]; |
| 37 | }; |
| 38 | |
| 39 | struct midi_parms |
| 40 | { |
| 41 | long prech_timeout; /* |
| 42 | * Timeout before the first ch |
| 43 | */ |
| 44 | }; |
| 45 | |
| 46 | static struct midi_buf *midi_out_buf[MAX_MIDI_DEV] = {NULL}; |
| 47 | static struct midi_buf *midi_in_buf[MAX_MIDI_DEV] = {NULL}; |
| 48 | static struct midi_parms parms[MAX_MIDI_DEV]; |
| 49 | |
| 50 | static void midi_poll(unsigned long dummy); |
| 51 | |
| 52 | |
| 53 | static struct timer_list poll_timer = TIMER_INITIALIZER(midi_poll, 0, 0); |
| 54 | |
| 55 | static volatile int open_devs; |
| 56 | static DEFINE_SPINLOCK(lock); |
| 57 | |
| 58 | #define DATA_AVAIL(q) (q->len) |
| 59 | #define SPACE_AVAIL(q) (MAX_QUEUE_SIZE - q->len) |
| 60 | |
| 61 | #define QUEUE_BYTE(q, data) \ |
| 62 | if (SPACE_AVAIL(q)) \ |
| 63 | { \ |
| 64 | unsigned long flags; \ |
| 65 | spin_lock_irqsave(&lock, flags); \ |
| 66 | q->queue[q->tail] = (data); \ |
| 67 | q->len++; q->tail = (q->tail+1) % MAX_QUEUE_SIZE; \ |
| 68 | spin_unlock_irqrestore(&lock, flags); \ |
| 69 | } |
| 70 | |
| 71 | #define REMOVE_BYTE(q, data) \ |
| 72 | if (DATA_AVAIL(q)) \ |
| 73 | { \ |
| 74 | unsigned long flags; \ |
| 75 | spin_lock_irqsave(&lock, flags); \ |
| 76 | data = q->queue[q->head]; \ |
| 77 | q->len--; q->head = (q->head+1) % MAX_QUEUE_SIZE; \ |
| 78 | spin_unlock_irqrestore(&lock, flags); \ |
| 79 | } |
| 80 | |
| 81 | static void drain_midi_queue(int dev) |
| 82 | { |
| 83 | |
| 84 | /* |
| 85 | * Give the Midi driver time to drain its output queues |
| 86 | */ |
| 87 | |
| 88 | if (midi_devs[dev]->buffer_status != NULL) |
| 89 | while (!signal_pending(current) && midi_devs[dev]->buffer_status(dev)) |
| 90 | interruptible_sleep_on_timeout(&midi_sleeper[dev], |
| 91 | HZ/10); |
| 92 | } |
| 93 | |
| 94 | static void midi_input_intr(int dev, unsigned char data) |
| 95 | { |
| 96 | if (midi_in_buf[dev] == NULL) |
| 97 | return; |
| 98 | |
| 99 | if (data == 0xfe) /* |
| 100 | * Active sensing |
| 101 | */ |
| 102 | return; /* |
| 103 | * Ignore |
| 104 | */ |
| 105 | |
| 106 | if (SPACE_AVAIL(midi_in_buf[dev])) { |
| 107 | QUEUE_BYTE(midi_in_buf[dev], data); |
| 108 | wake_up(&input_sleeper[dev]); |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | static void midi_output_intr(int dev) |
| 113 | { |
| 114 | /* |
| 115 | * Currently NOP |
| 116 | */ |
| 117 | } |
| 118 | |
| 119 | static void midi_poll(unsigned long dummy) |
| 120 | { |
| 121 | unsigned long flags; |
| 122 | int dev; |
| 123 | |
| 124 | spin_lock_irqsave(&lock, flags); |
| 125 | if (open_devs) |
| 126 | { |
| 127 | for (dev = 0; dev < num_midis; dev++) |
| 128 | if (midi_devs[dev] != NULL && midi_out_buf[dev] != NULL) |
| 129 | { |
| 130 | int ok = 1; |
| 131 | |
| 132 | while (DATA_AVAIL(midi_out_buf[dev]) && ok) |
| 133 | { |
| 134 | int c = midi_out_buf[dev]->queue[midi_out_buf[dev]->head]; |
| 135 | |
| 136 | spin_unlock_irqrestore(&lock,flags);/* Give some time to others */ |
| 137 | ok = midi_devs[dev]->outputc(dev, c); |
| 138 | spin_lock_irqsave(&lock, flags); |
| 139 | midi_out_buf[dev]->head = (midi_out_buf[dev]->head + 1) % MAX_QUEUE_SIZE; |
| 140 | midi_out_buf[dev]->len--; |
| 141 | } |
| 142 | |
| 143 | if (DATA_AVAIL(midi_out_buf[dev]) < 100) |
| 144 | wake_up(&midi_sleeper[dev]); |
| 145 | } |
| 146 | poll_timer.expires = (1) + jiffies; |
| 147 | add_timer(&poll_timer); |
| 148 | /* |
| 149 | * Come back later |
| 150 | */ |
| 151 | } |
| 152 | spin_unlock_irqrestore(&lock, flags); |
| 153 | } |
| 154 | |
| 155 | int MIDIbuf_open(int dev, struct file *file) |
| 156 | { |
| 157 | int mode, err; |
| 158 | |
| 159 | dev = dev >> 4; |
| 160 | mode = translate_mode(file); |
| 161 | |
| 162 | if (num_midis > MAX_MIDI_DEV) |
| 163 | { |
| 164 | printk(KERN_ERR "midi: Too many midi interfaces\n"); |
| 165 | num_midis = MAX_MIDI_DEV; |
| 166 | } |
| 167 | if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL) |
| 168 | return -ENXIO; |
| 169 | /* |
| 170 | * Interrupts disabled. Be careful |
| 171 | */ |
| 172 | |
| 173 | module_put(midi_devs[dev]->owner); |
| 174 | |
| 175 | if ((err = midi_devs[dev]->open(dev, mode, |
| 176 | midi_input_intr, midi_output_intr)) < 0) |
| 177 | return err; |
| 178 | |
| 179 | parms[dev].prech_timeout = MAX_SCHEDULE_TIMEOUT; |
| 180 | midi_in_buf[dev] = (struct midi_buf *) vmalloc(sizeof(struct midi_buf)); |
| 181 | |
| 182 | if (midi_in_buf[dev] == NULL) |
| 183 | { |
| 184 | printk(KERN_WARNING "midi: Can't allocate buffer\n"); |
| 185 | midi_devs[dev]->close(dev); |
| 186 | return -EIO; |
| 187 | } |
| 188 | midi_in_buf[dev]->len = midi_in_buf[dev]->head = midi_in_buf[dev]->tail = 0; |
| 189 | |
| 190 | midi_out_buf[dev] = (struct midi_buf *) vmalloc(sizeof(struct midi_buf)); |
| 191 | |
| 192 | if (midi_out_buf[dev] == NULL) |
| 193 | { |
| 194 | printk(KERN_WARNING "midi: Can't allocate buffer\n"); |
| 195 | midi_devs[dev]->close(dev); |
| 196 | vfree(midi_in_buf[dev]); |
| 197 | midi_in_buf[dev] = NULL; |
| 198 | return -EIO; |
| 199 | } |
| 200 | midi_out_buf[dev]->len = midi_out_buf[dev]->head = midi_out_buf[dev]->tail = 0; |
| 201 | open_devs++; |
| 202 | |
| 203 | init_waitqueue_head(&midi_sleeper[dev]); |
| 204 | init_waitqueue_head(&input_sleeper[dev]); |
| 205 | |
| 206 | if (open_devs < 2) /* This was first open */ |
| 207 | { |
| 208 | poll_timer.expires = 1 + jiffies; |
| 209 | add_timer(&poll_timer); /* Start polling */ |
| 210 | } |
| 211 | return err; |
| 212 | } |
| 213 | |
| 214 | void MIDIbuf_release(int dev, struct file *file) |
| 215 | { |
| 216 | int mode; |
| 217 | |
| 218 | dev = dev >> 4; |
| 219 | mode = translate_mode(file); |
| 220 | |
| 221 | if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL) |
| 222 | return; |
| 223 | |
| 224 | /* |
| 225 | * Wait until the queue is empty |
| 226 | */ |
| 227 | |
| 228 | if (mode != OPEN_READ) |
| 229 | { |
| 230 | midi_devs[dev]->outputc(dev, 0xfe); /* |
| 231 | * Active sensing to shut the |
| 232 | * devices |
| 233 | */ |
| 234 | |
| 235 | while (!signal_pending(current) && DATA_AVAIL(midi_out_buf[dev])) |
| 236 | interruptible_sleep_on(&midi_sleeper[dev]); |
| 237 | /* |
| 238 | * Sync |
| 239 | */ |
| 240 | |
| 241 | drain_midi_queue(dev); /* |
| 242 | * Ensure the output queues are empty |
| 243 | */ |
| 244 | } |
| 245 | |
| 246 | midi_devs[dev]->close(dev); |
| 247 | |
| 248 | open_devs--; |
| 249 | if (open_devs == 0) |
| 250 | del_timer_sync(&poll_timer); |
| 251 | vfree(midi_in_buf[dev]); |
| 252 | vfree(midi_out_buf[dev]); |
| 253 | midi_in_buf[dev] = NULL; |
| 254 | midi_out_buf[dev] = NULL; |
| 255 | |
| 256 | module_put(midi_devs[dev]->owner); |
| 257 | } |
| 258 | |
| 259 | int MIDIbuf_write(int dev, struct file *file, const char __user *buf, int count) |
| 260 | { |
| 261 | int c, n, i; |
| 262 | unsigned char tmp_data; |
| 263 | |
| 264 | dev = dev >> 4; |
| 265 | |
| 266 | if (!count) |
| 267 | return 0; |
| 268 | |
| 269 | c = 0; |
| 270 | |
| 271 | while (c < count) |
| 272 | { |
| 273 | n = SPACE_AVAIL(midi_out_buf[dev]); |
| 274 | |
| 275 | if (n == 0) { /* |
| 276 | * No space just now. |
| 277 | */ |
| 278 | |
| 279 | if (file->f_flags & O_NONBLOCK) { |
| 280 | c = -EAGAIN; |
| 281 | goto out; |
| 282 | } |
| 283 | |
| 284 | interruptible_sleep_on(&midi_sleeper[dev]); |
| 285 | if (signal_pending(current)) |
| 286 | { |
| 287 | c = -EINTR; |
| 288 | goto out; |
| 289 | } |
| 290 | n = SPACE_AVAIL(midi_out_buf[dev]); |
| 291 | } |
| 292 | if (n > (count - c)) |
| 293 | n = count - c; |
| 294 | |
| 295 | for (i = 0; i < n; i++) |
| 296 | { |
| 297 | /* BROKE BROKE BROKE - CANT DO THIS WITH CLI !! */ |
| 298 | /* yes, think the same, so I removed the cli() brackets |
| 299 | QUEUE_BYTE is protected against interrupts */ |
| 300 | if (copy_from_user((char *) &tmp_data, &(buf)[c], 1)) { |
| 301 | c = -EFAULT; |
| 302 | goto out; |
| 303 | } |
| 304 | QUEUE_BYTE(midi_out_buf[dev], tmp_data); |
| 305 | c++; |
| 306 | } |
| 307 | } |
| 308 | out: |
| 309 | return c; |
| 310 | } |
| 311 | |
| 312 | |
| 313 | int MIDIbuf_read(int dev, struct file *file, char __user *buf, int count) |
| 314 | { |
| 315 | int n, c = 0; |
| 316 | unsigned char tmp_data; |
| 317 | |
| 318 | dev = dev >> 4; |
| 319 | |
| 320 | if (!DATA_AVAIL(midi_in_buf[dev])) { /* |
| 321 | * No data yet, wait |
| 322 | */ |
| 323 | if (file->f_flags & O_NONBLOCK) { |
| 324 | c = -EAGAIN; |
| 325 | goto out; |
| 326 | } |
| 327 | interruptible_sleep_on_timeout(&input_sleeper[dev], |
| 328 | parms[dev].prech_timeout); |
| 329 | |
| 330 | if (signal_pending(current)) |
| 331 | c = -EINTR; /* The user is getting restless */ |
| 332 | } |
| 333 | if (c == 0 && DATA_AVAIL(midi_in_buf[dev])) /* |
| 334 | * Got some bytes |
| 335 | */ |
| 336 | { |
| 337 | n = DATA_AVAIL(midi_in_buf[dev]); |
| 338 | if (n > count) |
| 339 | n = count; |
| 340 | c = 0; |
| 341 | |
| 342 | while (c < n) |
| 343 | { |
| 344 | char *fixit; |
| 345 | REMOVE_BYTE(midi_in_buf[dev], tmp_data); |
| 346 | fixit = (char *) &tmp_data; |
| 347 | /* BROKE BROKE BROKE */ |
| 348 | /* yes removed the cli() brackets again |
| 349 | should q->len,tail&head be atomic_t? */ |
| 350 | if (copy_to_user(&(buf)[c], fixit, 1)) { |
| 351 | c = -EFAULT; |
| 352 | goto out; |
| 353 | } |
| 354 | c++; |
| 355 | } |
| 356 | } |
| 357 | out: |
| 358 | return c; |
| 359 | } |
| 360 | |
| 361 | int MIDIbuf_ioctl(int dev, struct file *file, |
| 362 | unsigned int cmd, void __user *arg) |
| 363 | { |
| 364 | int val; |
| 365 | |
| 366 | dev = dev >> 4; |
| 367 | |
| 368 | if (((cmd >> 8) & 0xff) == 'C') |
| 369 | { |
| 370 | if (midi_devs[dev]->coproc) /* Coprocessor ioctl */ |
| 371 | return midi_devs[dev]->coproc->ioctl(midi_devs[dev]->coproc->devc, cmd, arg, 0); |
| 372 | /* printk("/dev/midi%d: No coprocessor for this device\n", dev);*/ |
| 373 | return -ENXIO; |
| 374 | } |
| 375 | else |
| 376 | { |
| 377 | switch (cmd) |
| 378 | { |
| 379 | case SNDCTL_MIDI_PRETIME: |
| 380 | if (get_user(val, (int __user *)arg)) |
| 381 | return -EFAULT; |
| 382 | if (val < 0) |
| 383 | val = 0; |
| 384 | val = (HZ * val) / 10; |
| 385 | parms[dev].prech_timeout = val; |
| 386 | return put_user(val, (int __user *)arg); |
| 387 | |
| 388 | default: |
| 389 | if (!midi_devs[dev]->ioctl) |
| 390 | return -EINVAL; |
| 391 | return midi_devs[dev]->ioctl(dev, cmd, arg); |
| 392 | } |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | /* No kernel lock - fine */ |
| 397 | unsigned int MIDIbuf_poll(int dev, struct file *file, poll_table * wait) |
| 398 | { |
| 399 | unsigned int mask = 0; |
| 400 | |
| 401 | dev = dev >> 4; |
| 402 | |
| 403 | /* input */ |
| 404 | poll_wait(file, &input_sleeper[dev], wait); |
| 405 | if (DATA_AVAIL(midi_in_buf[dev])) |
| 406 | mask |= POLLIN | POLLRDNORM; |
| 407 | |
| 408 | /* output */ |
| 409 | poll_wait(file, &midi_sleeper[dev], wait); |
| 410 | if (!SPACE_AVAIL(midi_out_buf[dev])) |
| 411 | mask |= POLLOUT | POLLWRNORM; |
| 412 | |
| 413 | return mask; |
| 414 | } |
| 415 | |
| 416 | |
| 417 | void MIDIbuf_init(void) |
| 418 | { |
| 419 | /* drag in midi_syms.o */ |
| 420 | { |
| 421 | extern char midi_syms_symbol; |
| 422 | midi_syms_symbol = 0; |
| 423 | } |
| 424 | } |
| 425 | |
| 426 | int MIDIbuf_avail(int dev) |
| 427 | { |
| 428 | if (midi_in_buf[dev]) |
| 429 | return DATA_AVAIL (midi_in_buf[dev]); |
| 430 | return 0; |
| 431 | } |