1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * module/drivers.c 4 * functions for manipulating drivers 5 * 6 * COMEDI - Linux Control and Measurement Device Interface 7 * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org> 8 * Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net> 9 */ 10 11 #include <linux/device.h> 12 #include <linux/module.h> 13 #include <linux/errno.h> 14 #include <linux/kernel.h> 15 #include <linux/ioport.h> 16 #include <linux/slab.h> 17 #include <linux/dma-direction.h> 18 #include <linux/interrupt.h> 19 #include <linux/firmware.h> 20 #include <linux/comedi/comedidev.h> 21 #include "comedi_internal.h" 22 23 struct comedi_driver *comedi_drivers; 24 /* protects access to comedi_drivers */ 25 DEFINE_MUTEX(comedi_drivers_list_lock); 26 27 /** 28 * comedi_set_hw_dev() - Set hardware device associated with COMEDI device 29 * @dev: COMEDI device. 30 * @hw_dev: Hardware device. 31 * 32 * For automatically configured COMEDI devices (resulting from a call to 33 * comedi_auto_config() or one of its wrappers from the low-level COMEDI 34 * driver), comedi_set_hw_dev() is called automatically by the COMEDI core 35 * to associate the COMEDI device with the hardware device. It can also be 36 * called directly by "legacy" low-level COMEDI drivers that rely on the 37 * %COMEDI_DEVCONFIG ioctl to configure the hardware as long as the hardware 38 * has a &struct device. 39 * 40 * If @dev->hw_dev is NULL, it gets a reference to @hw_dev and sets 41 * @dev->hw_dev, otherwise, it does nothing. Calling it multiple times 42 * with the same hardware device is not considered an error. If it gets 43 * a reference to the hardware device, it will be automatically 'put' when 44 * the device is detached from COMEDI. 45 * 46 * Returns 0 if @dev->hw_dev was NULL or the same as @hw_dev, otherwise 47 * returns -EEXIST. 48 */ 49 int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev) 50 { 51 if (hw_dev == dev->hw_dev) 52 return 0; 53 if (dev->hw_dev) 54 return -EEXIST; 55 dev->hw_dev = get_device(hw_dev); 56 return 0; 57 } 58 EXPORT_SYMBOL_GPL(comedi_set_hw_dev); 59 60 static void comedi_clear_hw_dev(struct comedi_device *dev) 61 { 62 put_device(dev->hw_dev); 63 dev->hw_dev = NULL; 64 } 65 66 /** 67 * comedi_alloc_devpriv() - Allocate memory for the device private data 68 * @dev: COMEDI device. 69 * @size: Size of the memory to allocate. 70 * 71 * The allocated memory is zero-filled. @dev->private points to it on 72 * return. The memory will be automatically freed when the COMEDI device is 73 * "detached". 74 * 75 * Returns a pointer to the allocated memory, or NULL on failure. 76 */ 77 void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size) 78 { 79 dev->private = kzalloc(size, GFP_KERNEL); 80 return dev->private; 81 } 82 EXPORT_SYMBOL_GPL(comedi_alloc_devpriv); 83 84 /** 85 * comedi_alloc_subdevices() - Allocate subdevices for COMEDI device 86 * @dev: COMEDI device. 87 * @num_subdevices: Number of subdevices to allocate. 88 * 89 * Allocates and initializes an array of &struct comedi_subdevice for the 90 * COMEDI device. If successful, sets @dev->subdevices to point to the 91 * first one and @dev->n_subdevices to the number. 92 * 93 * Returns 0 on success, -EINVAL if @num_subdevices is < 1, or -ENOMEM if 94 * failed to allocate the memory. 95 */ 96 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices) 97 { 98 struct comedi_subdevice *s; 99 int i; 100 101 if (num_subdevices < 1) 102 return -EINVAL; 103 104 s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL); 105 if (!s) 106 return -ENOMEM; 107 dev->subdevices = s; 108 dev->n_subdevices = num_subdevices; 109 110 for (i = 0; i < num_subdevices; ++i) { 111 s = &dev->subdevices[i]; 112 s->device = dev; 113 s->index = i; 114 s->async_dma_dir = DMA_NONE; 115 spin_lock_init(&s->spin_lock); 116 s->minor = -1; 117 } 118 return 0; 119 } 120 EXPORT_SYMBOL_GPL(comedi_alloc_subdevices); 121 122 /** 123 * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback 124 * @s: COMEDI subdevice. 125 * 126 * This is called by low-level COMEDI drivers to allocate an array to record 127 * the last values written to a subdevice's analog output channels (at least 128 * by the %INSN_WRITE instruction), to allow them to be read back by an 129 * %INSN_READ instruction. It also provides a default handler for the 130 * %INSN_READ instruction unless one has already been set. 131 * 132 * On success, @s->readback points to the first element of the array, which 133 * is zero-filled. The low-level driver is responsible for updating its 134 * contents. @s->insn_read will be set to comedi_readback_insn_read() 135 * unless it is already non-NULL. 136 * 137 * Returns 0 on success, -EINVAL if the subdevice has no channels, or 138 * -ENOMEM on allocation failure. 139 */ 140 int comedi_alloc_subdev_readback(struct comedi_subdevice *s) 141 { 142 if (!s->n_chan) 143 return -EINVAL; 144 145 s->readback = kcalloc(s->n_chan, sizeof(*s->readback), GFP_KERNEL); 146 if (!s->readback) 147 return -ENOMEM; 148 149 if (!s->insn_read) 150 s->insn_read = comedi_readback_insn_read; 151 152 return 0; 153 } 154 EXPORT_SYMBOL_GPL(comedi_alloc_subdev_readback); 155 156 static void comedi_device_detach_cleanup(struct comedi_device *dev) 157 { 158 int i; 159 struct comedi_subdevice *s; 160 161 lockdep_assert_held(&dev->attach_lock); 162 lockdep_assert_held(&dev->mutex); 163 if (dev->subdevices) { 164 for (i = 0; i < dev->n_subdevices; i++) { 165 s = &dev->subdevices[i]; 166 if (comedi_can_auto_free_spriv(s)) 167 kfree(s->private); 168 comedi_free_subdevice_minor(s); 169 if (s->async) { 170 comedi_buf_alloc(dev, s, 0); 171 kfree(s->async); 172 } 173 kfree(s->readback); 174 } 175 kfree(dev->subdevices); 176 dev->subdevices = NULL; 177 dev->n_subdevices = 0; 178 } 179 kfree(dev->private); 180 if (!IS_ERR(dev->pacer)) 181 kfree(dev->pacer); 182 dev->private = NULL; 183 dev->pacer = NULL; 184 dev->driver = NULL; 185 dev->board_name = NULL; 186 dev->board_ptr = NULL; 187 dev->mmio = NULL; 188 dev->iobase = 0; 189 dev->iolen = 0; 190 dev->ioenabled = false; 191 dev->irq = 0; 192 dev->read_subdev = NULL; 193 dev->write_subdev = NULL; 194 dev->open = NULL; 195 dev->close = NULL; 196 comedi_clear_hw_dev(dev); 197 } 198 199 void comedi_device_detach(struct comedi_device *dev) 200 { 201 lockdep_assert_held(&dev->mutex); 202 comedi_device_cancel_all(dev); 203 down_write(&dev->attach_lock); 204 dev->attached = false; 205 dev->detach_count++; 206 if (dev->driver) 207 dev->driver->detach(dev); 208 comedi_device_detach_cleanup(dev); 209 up_write(&dev->attach_lock); 210 } 211 212 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) 213 { 214 return -EINVAL; 215 } 216 217 static int insn_device_inval(struct comedi_device *dev, 218 struct comedi_insn *insn, unsigned int *data) 219 { 220 return -EINVAL; 221 } 222 223 static unsigned int get_zero_valid_routes(struct comedi_device *dev, 224 unsigned int n_pairs, 225 unsigned int *pair_data) 226 { 227 return 0; 228 } 229 230 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, 231 struct comedi_insn *insn, unsigned int *data) 232 { 233 return -EINVAL; 234 } 235 236 /** 237 * comedi_readback_insn_read() - A generic (*insn_read) for subdevice readback. 238 * @dev: COMEDI device. 239 * @s: COMEDI subdevice. 240 * @insn: COMEDI instruction. 241 * @data: Pointer to return the readback data. 242 * 243 * Handles the %INSN_READ instruction for subdevices that use the readback 244 * array allocated by comedi_alloc_subdev_readback(). It may be used 245 * directly as the subdevice's handler (@s->insn_read) or called via a 246 * wrapper. 247 * 248 * @insn->n is normally 1, which will read a single value. If higher, the 249 * same element of the readback array will be read multiple times. 250 * 251 * Returns @insn->n on success, or -EINVAL if @s->readback is NULL. 252 */ 253 int comedi_readback_insn_read(struct comedi_device *dev, 254 struct comedi_subdevice *s, 255 struct comedi_insn *insn, 256 unsigned int *data) 257 { 258 unsigned int chan = CR_CHAN(insn->chanspec); 259 int i; 260 261 if (!s->readback) 262 return -EINVAL; 263 264 for (i = 0; i < insn->n; i++) 265 data[i] = s->readback[chan]; 266 267 return insn->n; 268 } 269 EXPORT_SYMBOL_GPL(comedi_readback_insn_read); 270 271 /** 272 * comedi_timeout() - Busy-wait for a driver condition to occur 273 * @dev: COMEDI device. 274 * @s: COMEDI subdevice. 275 * @insn: COMEDI instruction. 276 * @cb: Callback to check for the condition. 277 * @context: Private context from the driver. 278 * 279 * Busy-waits for up to a second (%COMEDI_TIMEOUT_MS) for the condition or 280 * some error (other than -EBUSY) to occur. The parameters @dev, @s, @insn, 281 * and @context are passed to the callback function, which returns -EBUSY to 282 * continue waiting or some other value to stop waiting (generally 0 if the 283 * condition occurred, or some error value). 284 * 285 * Returns -ETIMEDOUT if timed out, otherwise the return value from the 286 * callback function. 287 */ 288 int comedi_timeout(struct comedi_device *dev, 289 struct comedi_subdevice *s, 290 struct comedi_insn *insn, 291 int (*cb)(struct comedi_device *dev, 292 struct comedi_subdevice *s, 293 struct comedi_insn *insn, 294 unsigned long context), 295 unsigned long context) 296 { 297 unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS); 298 int ret; 299 300 while (time_before(jiffies, timeout)) { 301 ret = cb(dev, s, insn, context); 302 if (ret != -EBUSY) 303 return ret; /* success (0) or non EBUSY errno */ 304 cpu_relax(); 305 } 306 return -ETIMEDOUT; 307 } 308 EXPORT_SYMBOL_GPL(comedi_timeout); 309 310 /** 311 * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices 312 * @dev: COMEDI device. 313 * @s: COMEDI subdevice. 314 * @insn: COMEDI instruction. 315 * @data: Instruction parameters and return data. 316 * @mask: io_bits mask for grouped channels, or 0 for single channel. 317 * 318 * If @mask is 0, it is replaced with a single-bit mask corresponding to the 319 * channel number specified by @insn->chanspec. Otherwise, @mask 320 * corresponds to a group of channels (which should include the specified 321 * channel) that are always configured together as inputs or outputs. 322 * 323 * Partially handles the %INSN_CONFIG_DIO_INPUT, %INSN_CONFIG_DIO_OUTPUTS, 324 * and %INSN_CONFIG_DIO_QUERY instructions. The first two update 325 * @s->io_bits to record the directions of the masked channels. The last 326 * one sets @data[1] to the current direction of the group of channels 327 * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits. 328 * 329 * The caller is responsible for updating the DIO direction in the hardware 330 * registers if this function returns 0. 331 * 332 * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT 333 * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or 334 * -EINVAL for some other instruction. 335 */ 336 int comedi_dio_insn_config(struct comedi_device *dev, 337 struct comedi_subdevice *s, 338 struct comedi_insn *insn, 339 unsigned int *data, 340 unsigned int mask) 341 { 342 unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec); 343 344 if (!mask) 345 mask = chan_mask; 346 347 switch (data[0]) { 348 case INSN_CONFIG_DIO_INPUT: 349 s->io_bits &= ~mask; 350 break; 351 352 case INSN_CONFIG_DIO_OUTPUT: 353 s->io_bits |= mask; 354 break; 355 356 case INSN_CONFIG_DIO_QUERY: 357 data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT; 358 return insn->n; 359 360 default: 361 return -EINVAL; 362 } 363 364 return 0; 365 } 366 EXPORT_SYMBOL_GPL(comedi_dio_insn_config); 367 368 /** 369 * comedi_dio_update_state() - Update the internal state of DIO subdevices 370 * @s: COMEDI subdevice. 371 * @data: The channel mask and bits to update. 372 * 373 * Updates @s->state which holds the internal state of the outputs for DIO 374 * or DO subdevices (up to 32 channels). @data[0] contains a bit-mask of 375 * the channels to be updated. @data[1] contains a bit-mask of those 376 * channels to be set to '1'. The caller is responsible for updating the 377 * outputs in hardware according to @s->state. As a minimum, the channels 378 * in the returned bit-mask need to be updated. 379 * 380 * Returns @mask with non-existent channels removed. 381 */ 382 unsigned int comedi_dio_update_state(struct comedi_subdevice *s, 383 unsigned int *data) 384 { 385 unsigned int chanmask = (s->n_chan < 32) ? ((1 << s->n_chan) - 1) 386 : 0xffffffff; 387 unsigned int mask = data[0] & chanmask; 388 unsigned int bits = data[1]; 389 390 if (mask) { 391 s->state &= ~mask; 392 s->state |= (bits & mask); 393 } 394 395 return mask; 396 } 397 EXPORT_SYMBOL_GPL(comedi_dio_update_state); 398 399 /** 400 * comedi_bytes_per_scan_cmd() - Get length of asynchronous command "scan" in 401 * bytes 402 * @s: COMEDI subdevice. 403 * @cmd: COMEDI command. 404 * 405 * Determines the overall scan length according to the subdevice type and the 406 * number of channels in the scan for the specified command. 407 * 408 * For digital input, output or input/output subdevices, samples for 409 * multiple channels are assumed to be packed into one or more unsigned 410 * short or unsigned int values according to the subdevice's %SDF_LSAMPL 411 * flag. For other types of subdevice, samples are assumed to occupy a 412 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. 413 * 414 * Returns the overall scan length in bytes. 415 */ 416 unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s, 417 struct comedi_cmd *cmd) 418 { 419 unsigned int num_samples; 420 unsigned int bits_per_sample; 421 422 switch (s->type) { 423 case COMEDI_SUBD_DI: 424 case COMEDI_SUBD_DO: 425 case COMEDI_SUBD_DIO: 426 bits_per_sample = 8 * comedi_bytes_per_sample(s); 427 num_samples = DIV_ROUND_UP(cmd->scan_end_arg, bits_per_sample); 428 break; 429 default: 430 num_samples = cmd->scan_end_arg; 431 break; 432 } 433 return comedi_samples_to_bytes(s, num_samples); 434 } 435 EXPORT_SYMBOL_GPL(comedi_bytes_per_scan_cmd); 436 437 /** 438 * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes 439 * @s: COMEDI subdevice. 440 * 441 * Determines the overall scan length according to the subdevice type and the 442 * number of channels in the scan for the current command. 443 * 444 * For digital input, output or input/output subdevices, samples for 445 * multiple channels are assumed to be packed into one or more unsigned 446 * short or unsigned int values according to the subdevice's %SDF_LSAMPL 447 * flag. For other types of subdevice, samples are assumed to occupy a 448 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. 449 * 450 * Returns the overall scan length in bytes. 451 */ 452 unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s) 453 { 454 struct comedi_cmd *cmd = &s->async->cmd; 455 456 return comedi_bytes_per_scan_cmd(s, cmd); 457 } 458 EXPORT_SYMBOL_GPL(comedi_bytes_per_scan); 459 460 static unsigned int __comedi_nscans_left(struct comedi_subdevice *s, 461 unsigned int nscans) 462 { 463 struct comedi_async *async = s->async; 464 struct comedi_cmd *cmd = &async->cmd; 465 466 if (cmd->stop_src == TRIG_COUNT) { 467 unsigned int scans_left = 0; 468 469 if (async->scans_done < cmd->stop_arg) 470 scans_left = cmd->stop_arg - async->scans_done; 471 472 if (nscans > scans_left) 473 nscans = scans_left; 474 } 475 return nscans; 476 } 477 478 /** 479 * comedi_nscans_left() - Return the number of scans left in the command 480 * @s: COMEDI subdevice. 481 * @nscans: The expected number of scans or 0 for all available scans. 482 * 483 * If @nscans is 0, it is set to the number of scans available in the 484 * async buffer. 485 * 486 * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be 487 * checked against the number of scans remaining to complete the command. 488 * 489 * The return value will then be either the expected number of scans or the 490 * number of scans remaining to complete the command, whichever is fewer. 491 */ 492 unsigned int comedi_nscans_left(struct comedi_subdevice *s, 493 unsigned int nscans) 494 { 495 if (nscans == 0) { 496 unsigned int nbytes = comedi_buf_read_n_available(s); 497 498 nscans = nbytes / comedi_bytes_per_scan(s); 499 } 500 return __comedi_nscans_left(s, nscans); 501 } 502 EXPORT_SYMBOL_GPL(comedi_nscans_left); 503 504 /** 505 * comedi_nsamples_left() - Return the number of samples left in the command 506 * @s: COMEDI subdevice. 507 * @nsamples: The expected number of samples. 508 * 509 * Returns the number of samples remaining to complete the command, or the 510 * specified expected number of samples (@nsamples), whichever is fewer. 511 */ 512 unsigned int comedi_nsamples_left(struct comedi_subdevice *s, 513 unsigned int nsamples) 514 { 515 struct comedi_async *async = s->async; 516 struct comedi_cmd *cmd = &async->cmd; 517 unsigned long long scans_left; 518 unsigned long long samples_left; 519 520 if (cmd->stop_src != TRIG_COUNT) 521 return nsamples; 522 523 scans_left = __comedi_nscans_left(s, cmd->stop_arg); 524 if (!scans_left) 525 return 0; 526 527 samples_left = scans_left * cmd->scan_end_arg - 528 comedi_bytes_to_samples(s, async->scan_progress); 529 530 if (samples_left < nsamples) 531 return samples_left; 532 return nsamples; 533 } 534 EXPORT_SYMBOL_GPL(comedi_nsamples_left); 535 536 /** 537 * comedi_inc_scan_progress() - Update scan progress in asynchronous command 538 * @s: COMEDI subdevice. 539 * @num_bytes: Amount of data in bytes to increment scan progress. 540 * 541 * Increments the scan progress by the number of bytes specified by @num_bytes. 542 * If the scan progress reaches or exceeds the scan length in bytes, reduce 543 * it modulo the scan length in bytes and set the "end of scan" asynchronous 544 * event flag (%COMEDI_CB_EOS) to be processed later. 545 */ 546 void comedi_inc_scan_progress(struct comedi_subdevice *s, 547 unsigned int num_bytes) 548 { 549 struct comedi_async *async = s->async; 550 struct comedi_cmd *cmd = &async->cmd; 551 unsigned int scan_length = comedi_bytes_per_scan(s); 552 553 /* track the 'cur_chan' for non-SDF_PACKED subdevices */ 554 if (!(s->subdev_flags & SDF_PACKED)) { 555 async->cur_chan += comedi_bytes_to_samples(s, num_bytes); 556 async->cur_chan %= cmd->chanlist_len; 557 } 558 559 async->scan_progress += num_bytes; 560 if (async->scan_progress >= scan_length) { 561 unsigned int nscans = async->scan_progress / scan_length; 562 563 if (async->scans_done < (UINT_MAX - nscans)) 564 async->scans_done += nscans; 565 else 566 async->scans_done = UINT_MAX; 567 568 async->scan_progress %= scan_length; 569 async->events |= COMEDI_CB_EOS; 570 } 571 } 572 EXPORT_SYMBOL_GPL(comedi_inc_scan_progress); 573 574 /** 575 * comedi_handle_events() - Handle events and possibly stop acquisition 576 * @dev: COMEDI device. 577 * @s: COMEDI subdevice. 578 * 579 * Handles outstanding asynchronous acquisition event flags associated 580 * with the subdevice. Call the subdevice's @s->cancel() handler if the 581 * "end of acquisition", "error" or "overflow" event flags are set in order 582 * to stop the acquisition at the driver level. 583 * 584 * Calls comedi_event() to further process the event flags, which may mark 585 * the asynchronous command as no longer running, possibly terminated with 586 * an error, and may wake up tasks. 587 * 588 * Return a bit-mask of the handled events. 589 */ 590 unsigned int comedi_handle_events(struct comedi_device *dev, 591 struct comedi_subdevice *s) 592 { 593 unsigned int events = s->async->events; 594 595 if (events == 0) 596 return events; 597 598 if ((events & COMEDI_CB_CANCEL_MASK) && s->cancel) 599 s->cancel(dev, s); 600 601 comedi_event(dev, s); 602 603 return events; 604 } 605 EXPORT_SYMBOL_GPL(comedi_handle_events); 606 607 static int insn_rw_emulate_bits(struct comedi_device *dev, 608 struct comedi_subdevice *s, 609 struct comedi_insn *insn, 610 unsigned int *data) 611 { 612 struct comedi_insn _insn; 613 unsigned int chan = CR_CHAN(insn->chanspec); 614 unsigned int base_chan = (chan < 32) ? 0 : chan; 615 unsigned int _data[2]; 616 int ret; 617 618 memset(_data, 0, sizeof(_data)); 619 memset(&_insn, 0, sizeof(_insn)); 620 _insn.insn = INSN_BITS; 621 _insn.chanspec = base_chan; 622 _insn.n = 2; 623 _insn.subdev = insn->subdev; 624 625 if (insn->insn == INSN_WRITE) { 626 if (!(s->subdev_flags & SDF_WRITABLE)) 627 return -EINVAL; 628 _data[0] = 1 << (chan - base_chan); /* mask */ 629 _data[1] = data[0] ? (1 << (chan - base_chan)) : 0; /* bits */ 630 } 631 632 ret = s->insn_bits(dev, s, &_insn, _data); 633 if (ret < 0) 634 return ret; 635 636 if (insn->insn == INSN_READ) 637 data[0] = (_data[1] >> (chan - base_chan)) & 1; 638 639 return 1; 640 } 641 642 static int __comedi_device_postconfig_async(struct comedi_device *dev, 643 struct comedi_subdevice *s) 644 { 645 struct comedi_async *async; 646 unsigned int buf_size; 647 int ret; 648 649 lockdep_assert_held(&dev->mutex); 650 if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) { 651 dev_warn(dev->class_dev, 652 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n"); 653 return -EINVAL; 654 } 655 if (!s->do_cmdtest) { 656 dev_warn(dev->class_dev, 657 "async subdevices must have a do_cmdtest() function\n"); 658 return -EINVAL; 659 } 660 if (!s->cancel) 661 dev_warn(dev->class_dev, 662 "async subdevices should have a cancel() function\n"); 663 664 async = kzalloc(sizeof(*async), GFP_KERNEL); 665 if (!async) 666 return -ENOMEM; 667 668 init_waitqueue_head(&async->wait_head); 669 s->async = async; 670 671 async->max_bufsize = comedi_default_buf_maxsize_kb * 1024; 672 buf_size = comedi_default_buf_size_kb * 1024; 673 if (buf_size > async->max_bufsize) 674 buf_size = async->max_bufsize; 675 676 if (comedi_buf_alloc(dev, s, buf_size) < 0) { 677 dev_warn(dev->class_dev, "Buffer allocation failed\n"); 678 return -ENOMEM; 679 } 680 if (s->buf_change) { 681 ret = s->buf_change(dev, s); 682 if (ret < 0) 683 return ret; 684 } 685 686 comedi_alloc_subdevice_minor(s); 687 688 return 0; 689 } 690 691 static int __comedi_device_postconfig(struct comedi_device *dev) 692 { 693 struct comedi_subdevice *s; 694 int ret; 695 int i; 696 697 lockdep_assert_held(&dev->mutex); 698 if (!dev->insn_device_config) 699 dev->insn_device_config = insn_device_inval; 700 701 if (!dev->get_valid_routes) 702 dev->get_valid_routes = get_zero_valid_routes; 703 704 for (i = 0; i < dev->n_subdevices; i++) { 705 s = &dev->subdevices[i]; 706 707 if (s->type == COMEDI_SUBD_UNUSED) 708 continue; 709 710 if (s->type == COMEDI_SUBD_DO) { 711 if (s->n_chan < 32) 712 s->io_bits = (1 << s->n_chan) - 1; 713 else 714 s->io_bits = 0xffffffff; 715 } 716 717 if (s->len_chanlist == 0) 718 s->len_chanlist = 1; 719 720 if (s->do_cmd) { 721 ret = __comedi_device_postconfig_async(dev, s); 722 if (ret) 723 return ret; 724 } 725 726 if (!s->range_table && !s->range_table_list) 727 s->range_table = &range_unknown; 728 729 if (!s->insn_read && s->insn_bits) 730 s->insn_read = insn_rw_emulate_bits; 731 if (!s->insn_write && s->insn_bits) 732 s->insn_write = insn_rw_emulate_bits; 733 734 if (!s->insn_read) 735 s->insn_read = insn_inval; 736 if (!s->insn_write) 737 s->insn_write = insn_inval; 738 if (!s->insn_bits) 739 s->insn_bits = insn_inval; 740 if (!s->insn_config) 741 s->insn_config = insn_inval; 742 743 if (!s->poll) 744 s->poll = poll_invalid; 745 } 746 747 return 0; 748 } 749 750 /* do a little post-config cleanup */ 751 static int comedi_device_postconfig(struct comedi_device *dev) 752 { 753 int ret; 754 755 lockdep_assert_held(&dev->mutex); 756 ret = __comedi_device_postconfig(dev); 757 if (ret < 0) 758 return ret; 759 down_write(&dev->attach_lock); 760 dev->attached = true; 761 up_write(&dev->attach_lock); 762 return 0; 763 } 764 765 /* 766 * Generic recognize function for drivers that register their supported 767 * board names. 768 * 769 * 'driv->board_name' points to a 'const char *' member within the 770 * zeroth element of an array of some private board information 771 * structure, say 'struct foo_board' containing a member 'const char 772 * *board_name' that is initialized to point to a board name string that 773 * is one of the candidates matched against this function's 'name' 774 * parameter. 775 * 776 * 'driv->offset' is the size of the private board information 777 * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is 778 * the length of the array of private board information structures. 779 * 780 * If one of the board names in the array of private board information 781 * structures matches the name supplied to this function, the function 782 * returns a pointer to the pointer to the board name, otherwise it 783 * returns NULL. The return value ends up in the 'board_ptr' member of 784 * a 'struct comedi_device' that the low-level comedi driver's 785 * 'attach()' hook can convert to a point to a particular element of its 786 * array of private board information structures by subtracting the 787 * offset of the member that points to the board name. (No subtraction 788 * is required if the board name pointer is the first member of the 789 * private board information structure, which is generally the case.) 790 */ 791 static void *comedi_recognize(struct comedi_driver *driv, const char *name) 792 { 793 char **name_ptr = (char **)driv->board_name; 794 int i; 795 796 for (i = 0; i < driv->num_names; i++) { 797 if (strcmp(*name_ptr, name) == 0) 798 return name_ptr; 799 name_ptr = (void *)name_ptr + driv->offset; 800 } 801 802 return NULL; 803 } 804 805 static void comedi_report_boards(struct comedi_driver *driv) 806 { 807 unsigned int i; 808 const char *const *name_ptr; 809 810 pr_info("comedi: valid board names for %s driver are:\n", 811 driv->driver_name); 812 813 name_ptr = driv->board_name; 814 for (i = 0; i < driv->num_names; i++) { 815 pr_info(" %s\n", *name_ptr); 816 name_ptr = (const char **)((char *)name_ptr + driv->offset); 817 } 818 819 if (driv->num_names == 0) 820 pr_info(" %s\n", driv->driver_name); 821 } 822 823 /** 824 * comedi_load_firmware() - Request and load firmware for a device 825 * @dev: COMEDI device. 826 * @device: Hardware device. 827 * @name: The name of the firmware image. 828 * @cb: Callback to the upload the firmware image. 829 * @context: Private context from the driver. 830 * 831 * Sends a firmware request for the hardware device and waits for it. Calls 832 * the callback function to upload the firmware to the device, them releases 833 * the firmware. 834 * 835 * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number 836 * from the firmware request or the callback function. 837 */ 838 int comedi_load_firmware(struct comedi_device *dev, 839 struct device *device, 840 const char *name, 841 int (*cb)(struct comedi_device *dev, 842 const u8 *data, size_t size, 843 unsigned long context), 844 unsigned long context) 845 { 846 const struct firmware *fw; 847 int ret; 848 849 if (!cb) 850 return -EINVAL; 851 852 ret = request_firmware(&fw, name, device); 853 if (ret == 0) { 854 ret = cb(dev, fw->data, fw->size, context); 855 release_firmware(fw); 856 } 857 858 return min(ret, 0); 859 } 860 EXPORT_SYMBOL_GPL(comedi_load_firmware); 861 862 /** 863 * __comedi_request_region() - Request an I/O region for a legacy driver 864 * @dev: COMEDI device. 865 * @start: Base address of the I/O region. 866 * @len: Length of the I/O region. 867 * 868 * Requests the specified I/O port region which must start at a non-zero 869 * address. 870 * 871 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request 872 * fails. 873 */ 874 int __comedi_request_region(struct comedi_device *dev, 875 unsigned long start, unsigned long len) 876 { 877 if (!start) { 878 dev_warn(dev->class_dev, 879 "%s: a I/O base address must be specified\n", 880 dev->board_name); 881 return -EINVAL; 882 } 883 884 if (!request_region(start, len, dev->board_name)) { 885 dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n", 886 dev->board_name, start, len); 887 return -EIO; 888 } 889 890 return 0; 891 } 892 EXPORT_SYMBOL_GPL(__comedi_request_region); 893 894 /** 895 * comedi_request_region() - Request an I/O region for a legacy driver 896 * @dev: COMEDI device. 897 * @start: Base address of the I/O region. 898 * @len: Length of the I/O region. 899 * 900 * Requests the specified I/O port region which must start at a non-zero 901 * address. 902 * 903 * On success, @dev->iobase is set to the base address of the region and 904 * @dev->iolen is set to its length. 905 * 906 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request 907 * fails. 908 */ 909 int comedi_request_region(struct comedi_device *dev, 910 unsigned long start, unsigned long len) 911 { 912 int ret; 913 914 ret = __comedi_request_region(dev, start, len); 915 if (ret == 0) { 916 dev->iobase = start; 917 dev->iolen = len; 918 } 919 920 return ret; 921 } 922 EXPORT_SYMBOL_GPL(comedi_request_region); 923 924 /** 925 * comedi_legacy_detach() - A generic (*detach) function for legacy drivers 926 * @dev: COMEDI device. 927 * 928 * This is a simple, generic 'detach' handler for legacy COMEDI devices that 929 * just use a single I/O port region and possibly an IRQ and that don't need 930 * any special clean-up for their private device or subdevice storage. It 931 * can also be called by a driver-specific 'detach' handler. 932 * 933 * If @dev->irq is non-zero, the IRQ will be freed. If @dev->iobase and 934 * @dev->iolen are both non-zero, the I/O port region will be released. 935 */ 936 void comedi_legacy_detach(struct comedi_device *dev) 937 { 938 if (dev->irq) { 939 free_irq(dev->irq, dev); 940 dev->irq = 0; 941 } 942 if (dev->iobase && dev->iolen) { 943 release_region(dev->iobase, dev->iolen); 944 dev->iobase = 0; 945 dev->iolen = 0; 946 } 947 } 948 EXPORT_SYMBOL_GPL(comedi_legacy_detach); 949 950 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) 951 { 952 struct comedi_driver *driv; 953 int ret; 954 955 lockdep_assert_held(&dev->mutex); 956 if (dev->attached) 957 return -EBUSY; 958 959 mutex_lock(&comedi_drivers_list_lock); 960 for (driv = comedi_drivers; driv; driv = driv->next) { 961 if (!try_module_get(driv->module)) 962 continue; 963 if (driv->num_names) { 964 dev->board_ptr = comedi_recognize(driv, it->board_name); 965 if (dev->board_ptr) 966 break; 967 } else if (strcmp(driv->driver_name, it->board_name) == 0) { 968 break; 969 } 970 module_put(driv->module); 971 } 972 if (!driv) { 973 /* recognize has failed if we get here */ 974 /* report valid board names before returning error */ 975 for (driv = comedi_drivers; driv; driv = driv->next) { 976 if (!try_module_get(driv->module)) 977 continue; 978 comedi_report_boards(driv); 979 module_put(driv->module); 980 } 981 ret = -EIO; 982 goto out; 983 } 984 if (!driv->attach) { 985 /* driver does not support manual configuration */ 986 dev_warn(dev->class_dev, 987 "driver '%s' does not support attach using comedi_config\n", 988 driv->driver_name); 989 module_put(driv->module); 990 ret = -EIO; 991 goto out; 992 } 993 dev->driver = driv; 994 dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr 995 : dev->driver->driver_name; 996 ret = driv->attach(dev, it); 997 if (ret >= 0) 998 ret = comedi_device_postconfig(dev); 999 if (ret < 0) { 1000 comedi_device_detach(dev); 1001 module_put(driv->module); 1002 } 1003 /* On success, the driver module count has been incremented. */ 1004 out: 1005 mutex_unlock(&comedi_drivers_list_lock); 1006 return ret; 1007 } 1008 1009 /** 1010 * comedi_auto_config() - Create a COMEDI device for a hardware device 1011 * @hardware_device: Hardware device. 1012 * @driver: COMEDI low-level driver for the hardware device. 1013 * @context: Driver context for the auto_attach handler. 1014 * 1015 * Allocates a new COMEDI device for the hardware device and calls the 1016 * low-level driver's 'auto_attach' handler to set-up the hardware and 1017 * allocate the COMEDI subdevices. Additional "post-configuration" setting 1018 * up is performed on successful return from the 'auto_attach' handler. 1019 * If the 'auto_attach' handler fails, the low-level driver's 'detach' 1020 * handler will be called as part of the clean-up. 1021 * 1022 * This is usually called from a wrapper function in a bus-specific COMEDI 1023 * module, which in turn is usually called from a bus device 'probe' 1024 * function in the low-level driver. 1025 * 1026 * Returns 0 on success, -EINVAL if the parameters are invalid or the 1027 * post-configuration determines the driver has set the COMEDI device up 1028 * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of 1029 * COMEDI minor device numbers, or some negative error number returned by 1030 * the driver's 'auto_attach' handler. 1031 */ 1032 int comedi_auto_config(struct device *hardware_device, 1033 struct comedi_driver *driver, unsigned long context) 1034 { 1035 struct comedi_device *dev; 1036 int ret; 1037 1038 if (!hardware_device) { 1039 pr_warn("BUG! %s called with NULL hardware_device\n", __func__); 1040 return -EINVAL; 1041 } 1042 if (!driver) { 1043 dev_warn(hardware_device, 1044 "BUG! %s called with NULL comedi driver\n", __func__); 1045 return -EINVAL; 1046 } 1047 1048 if (!driver->auto_attach) { 1049 dev_warn(hardware_device, 1050 "BUG! comedi driver '%s' has no auto_attach handler\n", 1051 driver->driver_name); 1052 return -EINVAL; 1053 } 1054 1055 dev = comedi_alloc_board_minor(hardware_device); 1056 if (IS_ERR(dev)) { 1057 dev_warn(hardware_device, 1058 "driver '%s' could not create device.\n", 1059 driver->driver_name); 1060 return PTR_ERR(dev); 1061 } 1062 /* Note: comedi_alloc_board_minor() locked dev->mutex. */ 1063 lockdep_assert_held(&dev->mutex); 1064 1065 dev->driver = driver; 1066 dev->board_name = dev->driver->driver_name; 1067 ret = driver->auto_attach(dev, context); 1068 if (ret >= 0) 1069 ret = comedi_device_postconfig(dev); 1070 1071 if (ret < 0) { 1072 dev_warn(hardware_device, 1073 "driver '%s' failed to auto-configure device.\n", 1074 driver->driver_name); 1075 mutex_unlock(&dev->mutex); 1076 comedi_release_hardware_device(hardware_device); 1077 } else { 1078 /* 1079 * class_dev should be set properly here 1080 * after a successful auto config 1081 */ 1082 dev_info(dev->class_dev, 1083 "driver '%s' has successfully auto-configured '%s'.\n", 1084 driver->driver_name, dev->board_name); 1085 mutex_unlock(&dev->mutex); 1086 } 1087 return ret; 1088 } 1089 EXPORT_SYMBOL_GPL(comedi_auto_config); 1090 1091 /** 1092 * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device 1093 * @hardware_device: Hardware device previously passed to 1094 * comedi_auto_config(). 1095 * 1096 * Cleans up and eventually destroys the COMEDI device allocated by 1097 * comedi_auto_config() for the same hardware device. As part of this 1098 * clean-up, the low-level COMEDI driver's 'detach' handler will be called. 1099 * (The COMEDI device itself will persist in an unattached state if it is 1100 * still open, until it is released, and any mmapped buffers will persist 1101 * until they are munmapped.) 1102 * 1103 * This is usually called from a wrapper module in a bus-specific COMEDI 1104 * module, which in turn is usually set as the bus device 'remove' function 1105 * in the low-level COMEDI driver. 1106 */ 1107 void comedi_auto_unconfig(struct device *hardware_device) 1108 { 1109 if (!hardware_device) 1110 return; 1111 comedi_release_hardware_device(hardware_device); 1112 } 1113 EXPORT_SYMBOL_GPL(comedi_auto_unconfig); 1114 1115 /** 1116 * comedi_driver_register() - Register a low-level COMEDI driver 1117 * @driver: Low-level COMEDI driver. 1118 * 1119 * The low-level COMEDI driver is added to the list of registered COMEDI 1120 * drivers. This is used by the handler for the "/proc/comedi" file and is 1121 * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure 1122 * "legacy" COMEDI devices (for those low-level drivers that support it). 1123 * 1124 * Returns 0. 1125 */ 1126 int comedi_driver_register(struct comedi_driver *driver) 1127 { 1128 mutex_lock(&comedi_drivers_list_lock); 1129 driver->next = comedi_drivers; 1130 comedi_drivers = driver; 1131 mutex_unlock(&comedi_drivers_list_lock); 1132 1133 return 0; 1134 } 1135 EXPORT_SYMBOL_GPL(comedi_driver_register); 1136 1137 /** 1138 * comedi_driver_unregister() - Unregister a low-level COMEDI driver 1139 * @driver: Low-level COMEDI driver. 1140 * 1141 * The low-level COMEDI driver is removed from the list of registered COMEDI 1142 * drivers. Detaches any COMEDI devices attached to the driver, which will 1143 * result in the low-level driver's 'detach' handler being called for those 1144 * devices before this function returns. 1145 */ 1146 void comedi_driver_unregister(struct comedi_driver *driver) 1147 { 1148 struct comedi_driver *prev; 1149 int i; 1150 1151 /* unlink the driver */ 1152 mutex_lock(&comedi_drivers_list_lock); 1153 if (comedi_drivers == driver) { 1154 comedi_drivers = driver->next; 1155 } else { 1156 for (prev = comedi_drivers; prev->next; prev = prev->next) { 1157 if (prev->next == driver) { 1158 prev->next = driver->next; 1159 break; 1160 } 1161 } 1162 } 1163 mutex_unlock(&comedi_drivers_list_lock); 1164 1165 /* check for devices using this driver */ 1166 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { 1167 struct comedi_device *dev = comedi_dev_get_from_minor(i); 1168 1169 if (!dev) 1170 continue; 1171 1172 mutex_lock(&dev->mutex); 1173 if (dev->attached && dev->driver == driver) { 1174 if (dev->use_count) 1175 dev_warn(dev->class_dev, 1176 "BUG! detaching device with use_count=%d\n", 1177 dev->use_count); 1178 comedi_device_detach(dev); 1179 } 1180 mutex_unlock(&dev->mutex); 1181 comedi_dev_put(dev); 1182 } 1183 } 1184 EXPORT_SYMBOL_GPL(comedi_driver_unregister); 1185