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