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_write(&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_locked(struct comedi_device *dev) 200 { 201 lockdep_assert_held_write(&dev->attach_lock); 202 lockdep_assert_held(&dev->mutex); 203 comedi_device_cancel_all(dev); 204 dev->attached = false; 205 dev->detach_count++; 206 if (dev->driver) 207 dev->driver->detach(dev); 208 comedi_device_detach_cleanup(dev); 209 } 210 211 void comedi_device_detach(struct comedi_device *dev) 212 { 213 lockdep_assert_held(&dev->mutex); 214 down_write(&dev->attach_lock); 215 comedi_device_detach_locked(dev); 216 up_write(&dev->attach_lock); 217 } 218 219 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) 220 { 221 return -EINVAL; 222 } 223 224 static int insn_device_inval(struct comedi_device *dev, 225 struct comedi_insn *insn, unsigned int *data) 226 { 227 return -EINVAL; 228 } 229 230 static unsigned int get_zero_valid_routes(struct comedi_device *dev, 231 unsigned int n_pairs, 232 unsigned int *pair_data) 233 { 234 return 0; 235 } 236 237 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, 238 struct comedi_insn *insn, unsigned int *data) 239 { 240 return -EINVAL; 241 } 242 243 /** 244 * comedi_readback_insn_read() - A generic (*insn_read) for subdevice readback. 245 * @dev: COMEDI device. 246 * @s: COMEDI subdevice. 247 * @insn: COMEDI instruction. 248 * @data: Pointer to return the readback data. 249 * 250 * Handles the %INSN_READ instruction for subdevices that use the readback 251 * array allocated by comedi_alloc_subdev_readback(). It may be used 252 * directly as the subdevice's handler (@s->insn_read) or called via a 253 * wrapper. 254 * 255 * @insn->n is normally 1, which will read a single value. If higher, the 256 * same element of the readback array will be read multiple times. 257 * 258 * Returns @insn->n on success, or -EINVAL if @s->readback is NULL. 259 */ 260 int comedi_readback_insn_read(struct comedi_device *dev, 261 struct comedi_subdevice *s, 262 struct comedi_insn *insn, 263 unsigned int *data) 264 { 265 unsigned int chan = CR_CHAN(insn->chanspec); 266 int i; 267 268 if (!s->readback) 269 return -EINVAL; 270 271 for (i = 0; i < insn->n; i++) 272 data[i] = s->readback[chan]; 273 274 return insn->n; 275 } 276 EXPORT_SYMBOL_GPL(comedi_readback_insn_read); 277 278 /** 279 * comedi_timeout() - Busy-wait for a driver condition to occur 280 * @dev: COMEDI device. 281 * @s: COMEDI subdevice. 282 * @insn: COMEDI instruction. 283 * @cb: Callback to check for the condition. 284 * @context: Private context from the driver. 285 * 286 * Busy-waits for up to a second (%COMEDI_TIMEOUT_MS) for the condition or 287 * some error (other than -EBUSY) to occur. The parameters @dev, @s, @insn, 288 * and @context are passed to the callback function, which returns -EBUSY to 289 * continue waiting or some other value to stop waiting (generally 0 if the 290 * condition occurred, or some error value). 291 * 292 * Returns -ETIMEDOUT if timed out, otherwise the return value from the 293 * callback function. 294 */ 295 int comedi_timeout(struct comedi_device *dev, 296 struct comedi_subdevice *s, 297 struct comedi_insn *insn, 298 int (*cb)(struct comedi_device *dev, 299 struct comedi_subdevice *s, 300 struct comedi_insn *insn, 301 unsigned long context), 302 unsigned long context) 303 { 304 unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS); 305 int ret; 306 307 while (time_before(jiffies, timeout)) { 308 ret = cb(dev, s, insn, context); 309 if (ret != -EBUSY) 310 return ret; /* success (0) or non EBUSY errno */ 311 cpu_relax(); 312 } 313 return -ETIMEDOUT; 314 } 315 EXPORT_SYMBOL_GPL(comedi_timeout); 316 317 /** 318 * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices 319 * @dev: COMEDI device. 320 * @s: COMEDI subdevice. 321 * @insn: COMEDI instruction. 322 * @data: Instruction parameters and return data. 323 * @mask: io_bits mask for grouped channels, or 0 for single channel. 324 * 325 * If @mask is 0, it is replaced with a single-bit mask corresponding to the 326 * channel number specified by @insn->chanspec. Otherwise, @mask 327 * corresponds to a group of channels (which should include the specified 328 * channel) that are always configured together as inputs or outputs. 329 * 330 * Partially handles the %INSN_CONFIG_DIO_INPUT, %INSN_CONFIG_DIO_OUTPUTS, 331 * and %INSN_CONFIG_DIO_QUERY instructions. The first two update 332 * @s->io_bits to record the directions of the masked channels. The last 333 * one sets @data[1] to the current direction of the group of channels 334 * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits. 335 * 336 * The caller is responsible for updating the DIO direction in the hardware 337 * registers if this function returns 0. 338 * 339 * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT 340 * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or 341 * -EINVAL for some other instruction. 342 */ 343 int comedi_dio_insn_config(struct comedi_device *dev, 344 struct comedi_subdevice *s, 345 struct comedi_insn *insn, 346 unsigned int *data, 347 unsigned int mask) 348 { 349 unsigned int chan = CR_CHAN(insn->chanspec); 350 351 if (!mask && chan < 32) 352 mask = 1U << chan; 353 354 switch (data[0]) { 355 case INSN_CONFIG_DIO_INPUT: 356 s->io_bits &= ~mask; 357 break; 358 359 case INSN_CONFIG_DIO_OUTPUT: 360 s->io_bits |= mask; 361 break; 362 363 case INSN_CONFIG_DIO_QUERY: 364 data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT; 365 return insn->n; 366 367 default: 368 return -EINVAL; 369 } 370 371 return 0; 372 } 373 EXPORT_SYMBOL_GPL(comedi_dio_insn_config); 374 375 /** 376 * comedi_dio_update_state() - Update the internal state of DIO subdevices 377 * @s: COMEDI subdevice. 378 * @data: The channel mask and bits to update. 379 * 380 * Updates @s->state which holds the internal state of the outputs for DIO 381 * or DO subdevices (up to 32 channels). @data[0] contains a bit-mask of 382 * the channels to be updated. @data[1] contains a bit-mask of those 383 * channels to be set to '1'. The caller is responsible for updating the 384 * outputs in hardware according to @s->state. As a minimum, the channels 385 * in the returned bit-mask need to be updated. 386 * 387 * Returns @mask with non-existent channels removed. 388 */ 389 unsigned int comedi_dio_update_state(struct comedi_subdevice *s, 390 unsigned int *data) 391 { 392 unsigned int chanmask = (s->n_chan < 32) ? ((1U << s->n_chan) - 1) 393 : 0xffffffff; 394 unsigned int mask = data[0] & chanmask; 395 unsigned int bits = data[1]; 396 397 if (mask) { 398 s->state &= ~mask; 399 s->state |= (bits & mask); 400 } 401 402 return mask; 403 } 404 EXPORT_SYMBOL_GPL(comedi_dio_update_state); 405 406 /** 407 * comedi_bytes_per_scan_cmd() - Get length of asynchronous command "scan" in 408 * bytes 409 * @s: COMEDI subdevice. 410 * @cmd: COMEDI command. 411 * 412 * Determines the overall scan length according to the subdevice type and the 413 * number of channels in the scan for the specified command. 414 * 415 * For digital input, output or input/output subdevices, samples for 416 * multiple channels are assumed to be packed into one or more unsigned 417 * short or unsigned int values according to the subdevice's %SDF_LSAMPL 418 * flag. For other types of subdevice, samples are assumed to occupy a 419 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. 420 * 421 * Returns the overall scan length in bytes. 422 */ 423 unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s, 424 struct comedi_cmd *cmd) 425 { 426 unsigned int num_samples; 427 unsigned int bits_per_sample; 428 429 switch (s->type) { 430 case COMEDI_SUBD_DI: 431 case COMEDI_SUBD_DO: 432 case COMEDI_SUBD_DIO: 433 bits_per_sample = 8 * comedi_bytes_per_sample(s); 434 num_samples = DIV_ROUND_UP(cmd->scan_end_arg, bits_per_sample); 435 break; 436 default: 437 num_samples = cmd->scan_end_arg; 438 break; 439 } 440 return comedi_samples_to_bytes(s, num_samples); 441 } 442 EXPORT_SYMBOL_GPL(comedi_bytes_per_scan_cmd); 443 444 /** 445 * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes 446 * @s: COMEDI subdevice. 447 * 448 * Determines the overall scan length according to the subdevice type and the 449 * number of channels in the scan for the current command. 450 * 451 * For digital input, output or input/output subdevices, samples for 452 * multiple channels are assumed to be packed into one or more unsigned 453 * short or unsigned int values according to the subdevice's %SDF_LSAMPL 454 * flag. For other types of subdevice, samples are assumed to occupy a 455 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. 456 * 457 * Returns the overall scan length in bytes. 458 */ 459 unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s) 460 { 461 struct comedi_cmd *cmd = &s->async->cmd; 462 463 return comedi_bytes_per_scan_cmd(s, cmd); 464 } 465 EXPORT_SYMBOL_GPL(comedi_bytes_per_scan); 466 467 static unsigned int __comedi_nscans_left(struct comedi_subdevice *s, 468 unsigned int nscans) 469 { 470 struct comedi_async *async = s->async; 471 struct comedi_cmd *cmd = &async->cmd; 472 473 if (cmd->stop_src == TRIG_COUNT) { 474 unsigned int scans_left = 0; 475 476 if (async->scans_done < cmd->stop_arg) 477 scans_left = cmd->stop_arg - async->scans_done; 478 479 if (nscans > scans_left) 480 nscans = scans_left; 481 } 482 return nscans; 483 } 484 485 /** 486 * comedi_nscans_left() - Return the number of scans left in the command 487 * @s: COMEDI subdevice. 488 * @nscans: The expected number of scans or 0 for all available scans. 489 * 490 * If @nscans is 0, it is set to the number of scans available in the 491 * async buffer. 492 * 493 * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be 494 * checked against the number of scans remaining to complete the command. 495 * 496 * The return value will then be either the expected number of scans or the 497 * number of scans remaining to complete the command, whichever is fewer. 498 */ 499 unsigned int comedi_nscans_left(struct comedi_subdevice *s, 500 unsigned int nscans) 501 { 502 if (nscans == 0) { 503 unsigned int nbytes = comedi_buf_read_n_available(s); 504 505 nscans = nbytes / comedi_bytes_per_scan(s); 506 } 507 return __comedi_nscans_left(s, nscans); 508 } 509 EXPORT_SYMBOL_GPL(comedi_nscans_left); 510 511 /** 512 * comedi_nsamples_left() - Return the number of samples left in the command 513 * @s: COMEDI subdevice. 514 * @nsamples: The expected number of samples. 515 * 516 * Returns the number of samples remaining to complete the command, or the 517 * specified expected number of samples (@nsamples), whichever is fewer. 518 */ 519 unsigned int comedi_nsamples_left(struct comedi_subdevice *s, 520 unsigned int nsamples) 521 { 522 struct comedi_async *async = s->async; 523 struct comedi_cmd *cmd = &async->cmd; 524 unsigned long long scans_left; 525 unsigned long long samples_left; 526 527 if (cmd->stop_src != TRIG_COUNT) 528 return nsamples; 529 530 scans_left = __comedi_nscans_left(s, cmd->stop_arg); 531 if (!scans_left) 532 return 0; 533 534 samples_left = scans_left * cmd->scan_end_arg - 535 comedi_bytes_to_samples(s, async->scan_progress); 536 537 if (samples_left < nsamples) 538 return samples_left; 539 return nsamples; 540 } 541 EXPORT_SYMBOL_GPL(comedi_nsamples_left); 542 543 /** 544 * comedi_inc_scan_progress() - Update scan progress in asynchronous command 545 * @s: COMEDI subdevice. 546 * @num_bytes: Amount of data in bytes to increment scan progress. 547 * 548 * Increments the scan progress by the number of bytes specified by @num_bytes. 549 * If the scan progress reaches or exceeds the scan length in bytes, reduce 550 * it modulo the scan length in bytes and set the "end of scan" asynchronous 551 * event flag (%COMEDI_CB_EOS) to be processed later. 552 */ 553 void comedi_inc_scan_progress(struct comedi_subdevice *s, 554 unsigned int num_bytes) 555 { 556 struct comedi_async *async = s->async; 557 struct comedi_cmd *cmd = &async->cmd; 558 unsigned int scan_length = comedi_bytes_per_scan(s); 559 560 /* track the 'cur_chan' for non-SDF_PACKED subdevices */ 561 if (!(s->subdev_flags & SDF_PACKED)) { 562 async->cur_chan += comedi_bytes_to_samples(s, num_bytes); 563 async->cur_chan %= cmd->chanlist_len; 564 } 565 566 async->scan_progress += num_bytes; 567 if (async->scan_progress >= scan_length) { 568 unsigned int nscans = async->scan_progress / scan_length; 569 570 if (async->scans_done < (UINT_MAX - nscans)) 571 async->scans_done += nscans; 572 else 573 async->scans_done = UINT_MAX; 574 575 async->scan_progress %= scan_length; 576 async->events |= COMEDI_CB_EOS; 577 } 578 } 579 EXPORT_SYMBOL_GPL(comedi_inc_scan_progress); 580 581 /** 582 * comedi_handle_events() - Handle events and possibly stop acquisition 583 * @dev: COMEDI device. 584 * @s: COMEDI subdevice. 585 * 586 * Handles outstanding asynchronous acquisition event flags associated 587 * with the subdevice. Call the subdevice's @s->cancel() handler if the 588 * "end of acquisition", "error" or "overflow" event flags are set in order 589 * to stop the acquisition at the driver level. 590 * 591 * Calls comedi_event() to further process the event flags, which may mark 592 * the asynchronous command as no longer running, possibly terminated with 593 * an error, and may wake up tasks. 594 * 595 * Return a bit-mask of the handled events. 596 */ 597 unsigned int comedi_handle_events(struct comedi_device *dev, 598 struct comedi_subdevice *s) 599 { 600 unsigned int events = s->async->events; 601 602 if (events == 0) 603 return events; 604 605 if ((events & COMEDI_CB_CANCEL_MASK) && s->cancel) 606 s->cancel(dev, s); 607 608 comedi_event(dev, s); 609 610 return events; 611 } 612 EXPORT_SYMBOL_GPL(comedi_handle_events); 613 614 static int insn_rw_emulate_bits(struct comedi_device *dev, 615 struct comedi_subdevice *s, 616 struct comedi_insn *insn, 617 unsigned int *data) 618 { 619 struct comedi_insn _insn; 620 unsigned int chan = CR_CHAN(insn->chanspec); 621 unsigned int base_chan = (chan < 32) ? 0 : chan; 622 unsigned int _data[2]; 623 unsigned int i; 624 int ret; 625 626 memset(_data, 0, sizeof(_data)); 627 memset(&_insn, 0, sizeof(_insn)); 628 _insn.insn = INSN_BITS; 629 _insn.chanspec = base_chan; 630 _insn.n = 2; 631 _insn.subdev = insn->subdev; 632 633 if (insn->insn == INSN_WRITE) { 634 if (!(s->subdev_flags & SDF_WRITABLE)) 635 return -EINVAL; 636 _data[0] = 1U << (chan - base_chan); /* mask */ 637 } 638 for (i = 0; i < insn->n; i++) { 639 if (insn->insn == INSN_WRITE) 640 _data[1] = data[i] ? _data[0] : 0; /* bits */ 641 642 ret = s->insn_bits(dev, s, &_insn, _data); 643 if (ret < 0) 644 return ret; 645 646 if (insn->insn == INSN_READ) 647 data[i] = (_data[1] >> (chan - base_chan)) & 1; 648 } 649 650 return insn->n; 651 } 652 653 static int __comedi_device_postconfig_async(struct comedi_device *dev, 654 struct comedi_subdevice *s) 655 { 656 struct comedi_async *async; 657 unsigned int buf_size; 658 int ret; 659 660 lockdep_assert_held(&dev->mutex); 661 if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) { 662 dev_warn(dev->class_dev, 663 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n"); 664 return -EINVAL; 665 } 666 if (!s->do_cmdtest) { 667 dev_warn(dev->class_dev, 668 "async subdevices must have a do_cmdtest() function\n"); 669 return -EINVAL; 670 } 671 if (!s->cancel) 672 dev_warn(dev->class_dev, 673 "async subdevices should have a cancel() function\n"); 674 675 async = kzalloc(sizeof(*async), GFP_KERNEL); 676 if (!async) 677 return -ENOMEM; 678 679 init_waitqueue_head(&async->wait_head); 680 init_completion(&async->run_complete); 681 s->async = async; 682 683 async->max_bufsize = comedi_default_buf_maxsize_kb * 1024; 684 buf_size = comedi_default_buf_size_kb * 1024; 685 if (buf_size > async->max_bufsize) 686 buf_size = async->max_bufsize; 687 688 if (comedi_buf_alloc(dev, s, buf_size) < 0) { 689 dev_warn(dev->class_dev, "Buffer allocation failed\n"); 690 return -ENOMEM; 691 } 692 if (s->buf_change) { 693 ret = s->buf_change(dev, s); 694 if (ret < 0) 695 return ret; 696 } 697 698 comedi_alloc_subdevice_minor(s); 699 700 return 0; 701 } 702 703 static int __comedi_device_postconfig(struct comedi_device *dev) 704 { 705 struct comedi_subdevice *s; 706 int ret; 707 int i; 708 709 lockdep_assert_held(&dev->mutex); 710 if (!dev->insn_device_config) 711 dev->insn_device_config = insn_device_inval; 712 713 if (!dev->get_valid_routes) 714 dev->get_valid_routes = get_zero_valid_routes; 715 716 for (i = 0; i < dev->n_subdevices; i++) { 717 s = &dev->subdevices[i]; 718 719 if (s->type == COMEDI_SUBD_UNUSED) 720 continue; 721 722 if (s->type == COMEDI_SUBD_DO) { 723 if (s->n_chan < 32) 724 s->io_bits = (1U << s->n_chan) - 1; 725 else 726 s->io_bits = 0xffffffff; 727 } 728 729 if (s->len_chanlist == 0) 730 s->len_chanlist = 1; 731 732 if (s->do_cmd) { 733 ret = __comedi_device_postconfig_async(dev, s); 734 if (ret) 735 return ret; 736 } 737 738 if (!s->range_table && !s->range_table_list) 739 s->range_table = &range_unknown; 740 741 if (!s->insn_read && s->insn_bits) 742 s->insn_read = insn_rw_emulate_bits; 743 if (!s->insn_write && s->insn_bits) 744 s->insn_write = insn_rw_emulate_bits; 745 746 if (!s->insn_read) 747 s->insn_read = insn_inval; 748 if (!s->insn_write) 749 s->insn_write = insn_inval; 750 if (!s->insn_bits) 751 s->insn_bits = insn_inval; 752 if (!s->insn_config) 753 s->insn_config = insn_inval; 754 755 if (!s->poll) 756 s->poll = poll_invalid; 757 } 758 759 return 0; 760 } 761 762 /* do a little post-config cleanup */ 763 static int comedi_device_postconfig(struct comedi_device *dev) 764 { 765 int ret; 766 767 lockdep_assert_held(&dev->mutex); 768 ret = __comedi_device_postconfig(dev); 769 if (ret < 0) 770 return ret; 771 down_write(&dev->attach_lock); 772 dev->attached = true; 773 up_write(&dev->attach_lock); 774 return 0; 775 } 776 777 /* 778 * Generic recognize function for drivers that register their supported 779 * board names. 780 * 781 * 'driv->board_name' points to a 'const char *' member within the 782 * zeroth element of an array of some private board information 783 * structure, say 'struct foo_board' containing a member 'const char 784 * *board_name' that is initialized to point to a board name string that 785 * is one of the candidates matched against this function's 'name' 786 * parameter. 787 * 788 * 'driv->offset' is the size of the private board information 789 * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is 790 * the length of the array of private board information structures. 791 * 792 * If one of the board names in the array of private board information 793 * structures matches the name supplied to this function, the function 794 * returns a pointer to the pointer to the board name, otherwise it 795 * returns NULL. The return value ends up in the 'board_ptr' member of 796 * a 'struct comedi_device' that the low-level comedi driver's 797 * 'attach()' hook can convert to a point to a particular element of its 798 * array of private board information structures by subtracting the 799 * offset of the member that points to the board name. (No subtraction 800 * is required if the board name pointer is the first member of the 801 * private board information structure, which is generally the case.) 802 */ 803 static void *comedi_recognize(struct comedi_driver *driv, const char *name) 804 { 805 char **name_ptr = (char **)driv->board_name; 806 int i; 807 808 for (i = 0; i < driv->num_names; i++) { 809 if (strcmp(*name_ptr, name) == 0) 810 return name_ptr; 811 name_ptr = (void *)name_ptr + driv->offset; 812 } 813 814 return NULL; 815 } 816 817 static void comedi_report_boards(struct comedi_driver *driv) 818 { 819 unsigned int i; 820 const char *const *name_ptr; 821 822 pr_info("comedi: valid board names for %s driver are:\n", 823 driv->driver_name); 824 825 name_ptr = driv->board_name; 826 for (i = 0; i < driv->num_names; i++) { 827 pr_info(" %s\n", *name_ptr); 828 name_ptr = (const char **)((char *)name_ptr + driv->offset); 829 } 830 831 if (driv->num_names == 0) 832 pr_info(" %s\n", driv->driver_name); 833 } 834 835 /** 836 * comedi_load_firmware() - Request and load firmware for a device 837 * @dev: COMEDI device. 838 * @device: Hardware device. 839 * @name: The name of the firmware image. 840 * @cb: Callback to the upload the firmware image. 841 * @context: Private context from the driver. 842 * 843 * Sends a firmware request for the hardware device and waits for it. Calls 844 * the callback function to upload the firmware to the device, them releases 845 * the firmware. 846 * 847 * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number 848 * from the firmware request or the callback function. 849 */ 850 int comedi_load_firmware(struct comedi_device *dev, 851 struct device *device, 852 const char *name, 853 int (*cb)(struct comedi_device *dev, 854 const u8 *data, size_t size, 855 unsigned long context), 856 unsigned long context) 857 { 858 const struct firmware *fw; 859 int ret; 860 861 if (!cb) 862 return -EINVAL; 863 864 ret = request_firmware(&fw, name, device); 865 if (ret == 0) { 866 ret = cb(dev, fw->data, fw->size, context); 867 release_firmware(fw); 868 } 869 870 return min(ret, 0); 871 } 872 EXPORT_SYMBOL_GPL(comedi_load_firmware); 873 874 /** 875 * __comedi_request_region() - Request an I/O region for a legacy driver 876 * @dev: COMEDI device. 877 * @start: Base address of the I/O region. 878 * @len: Length of the I/O region. 879 * 880 * Requests the specified I/O port region which must start at a non-zero 881 * address. 882 * 883 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request 884 * fails. 885 */ 886 int __comedi_request_region(struct comedi_device *dev, 887 unsigned long start, unsigned long len) 888 { 889 if (!start) { 890 dev_warn(dev->class_dev, 891 "%s: a I/O base address must be specified\n", 892 dev->board_name); 893 return -EINVAL; 894 } 895 896 if (!request_region(start, len, dev->board_name)) { 897 dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n", 898 dev->board_name, start, len); 899 return -EIO; 900 } 901 902 return 0; 903 } 904 EXPORT_SYMBOL_GPL(__comedi_request_region); 905 906 /** 907 * comedi_request_region() - Request an I/O region for a legacy driver 908 * @dev: COMEDI device. 909 * @start: Base address of the I/O region. 910 * @len: Length of the I/O region. 911 * 912 * Requests the specified I/O port region which must start at a non-zero 913 * address. 914 * 915 * On success, @dev->iobase is set to the base address of the region and 916 * @dev->iolen is set to its length. 917 * 918 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request 919 * fails. 920 */ 921 int comedi_request_region(struct comedi_device *dev, 922 unsigned long start, unsigned long len) 923 { 924 int ret; 925 926 ret = __comedi_request_region(dev, start, len); 927 if (ret == 0) { 928 dev->iobase = start; 929 dev->iolen = len; 930 } 931 932 return ret; 933 } 934 EXPORT_SYMBOL_GPL(comedi_request_region); 935 936 /** 937 * comedi_legacy_detach() - A generic (*detach) function for legacy drivers 938 * @dev: COMEDI device. 939 * 940 * This is a simple, generic 'detach' handler for legacy COMEDI devices that 941 * just use a single I/O port region and possibly an IRQ and that don't need 942 * any special clean-up for their private device or subdevice storage. It 943 * can also be called by a driver-specific 'detach' handler. 944 * 945 * If @dev->irq is non-zero, the IRQ will be freed. If @dev->iobase and 946 * @dev->iolen are both non-zero, the I/O port region will be released. 947 */ 948 void comedi_legacy_detach(struct comedi_device *dev) 949 { 950 if (dev->irq) { 951 free_irq(dev->irq, dev); 952 dev->irq = 0; 953 } 954 if (dev->iobase && dev->iolen) { 955 release_region(dev->iobase, dev->iolen); 956 dev->iobase = 0; 957 dev->iolen = 0; 958 } 959 } 960 EXPORT_SYMBOL_GPL(comedi_legacy_detach); 961 962 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) 963 { 964 struct comedi_driver *driv; 965 int ret; 966 967 lockdep_assert_held(&dev->mutex); 968 if (dev->attached) 969 return -EBUSY; 970 971 mutex_lock(&comedi_drivers_list_lock); 972 for (driv = comedi_drivers; driv; driv = driv->next) { 973 if (!try_module_get(driv->module)) 974 continue; 975 if (driv->num_names) { 976 dev->board_ptr = comedi_recognize(driv, it->board_name); 977 if (dev->board_ptr) 978 break; 979 } else if (strcmp(driv->driver_name, it->board_name) == 0) { 980 break; 981 } 982 module_put(driv->module); 983 } 984 if (!driv) { 985 /* recognize has failed if we get here */ 986 /* report valid board names before returning error */ 987 for (driv = comedi_drivers; driv; driv = driv->next) { 988 if (!try_module_get(driv->module)) 989 continue; 990 comedi_report_boards(driv); 991 module_put(driv->module); 992 } 993 ret = -EIO; 994 goto out; 995 } 996 if (!driv->attach) { 997 /* driver does not support manual configuration */ 998 dev_warn(dev->class_dev, 999 "driver '%s' does not support attach using comedi_config\n", 1000 driv->driver_name); 1001 module_put(driv->module); 1002 ret = -EIO; 1003 goto out; 1004 } 1005 dev->driver = driv; 1006 dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr 1007 : dev->driver->driver_name; 1008 ret = driv->attach(dev, it); 1009 if (ret >= 0) 1010 ret = comedi_device_postconfig(dev); 1011 if (ret < 0) { 1012 comedi_device_detach(dev); 1013 module_put(driv->module); 1014 } 1015 /* On success, the driver module count has been incremented. */ 1016 out: 1017 mutex_unlock(&comedi_drivers_list_lock); 1018 return ret; 1019 } 1020 1021 /** 1022 * comedi_auto_config() - Create a COMEDI device for a hardware device 1023 * @hardware_device: Hardware device. 1024 * @driver: COMEDI low-level driver for the hardware device. 1025 * @context: Driver context for the auto_attach handler. 1026 * 1027 * Allocates a new COMEDI device for the hardware device and calls the 1028 * low-level driver's 'auto_attach' handler to set-up the hardware and 1029 * allocate the COMEDI subdevices. Additional "post-configuration" setting 1030 * up is performed on successful return from the 'auto_attach' handler. 1031 * If the 'auto_attach' handler fails, the low-level driver's 'detach' 1032 * handler will be called as part of the clean-up. 1033 * 1034 * This is usually called from a wrapper function in a bus-specific COMEDI 1035 * module, which in turn is usually called from a bus device 'probe' 1036 * function in the low-level driver. 1037 * 1038 * Returns 0 on success, -EINVAL if the parameters are invalid or the 1039 * post-configuration determines the driver has set the COMEDI device up 1040 * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of 1041 * COMEDI minor device numbers, or some negative error number returned by 1042 * the driver's 'auto_attach' handler. 1043 */ 1044 int comedi_auto_config(struct device *hardware_device, 1045 struct comedi_driver *driver, unsigned long context) 1046 { 1047 struct comedi_device *dev; 1048 int ret; 1049 1050 if (!hardware_device) { 1051 pr_warn("BUG! %s called with NULL hardware_device\n", __func__); 1052 return -EINVAL; 1053 } 1054 if (!driver) { 1055 dev_warn(hardware_device, 1056 "BUG! %s called with NULL comedi driver\n", __func__); 1057 return -EINVAL; 1058 } 1059 1060 if (!driver->auto_attach) { 1061 dev_warn(hardware_device, 1062 "BUG! comedi driver '%s' has no auto_attach handler\n", 1063 driver->driver_name); 1064 return -EINVAL; 1065 } 1066 1067 dev = comedi_alloc_board_minor(hardware_device); 1068 if (IS_ERR(dev)) { 1069 dev_warn(hardware_device, 1070 "driver '%s' could not create device.\n", 1071 driver->driver_name); 1072 return PTR_ERR(dev); 1073 } 1074 /* Note: comedi_alloc_board_minor() locked dev->mutex. */ 1075 lockdep_assert_held(&dev->mutex); 1076 1077 dev->driver = driver; 1078 dev->board_name = dev->driver->driver_name; 1079 ret = driver->auto_attach(dev, context); 1080 if (ret >= 0) 1081 ret = comedi_device_postconfig(dev); 1082 1083 if (ret < 0) { 1084 dev_warn(hardware_device, 1085 "driver '%s' failed to auto-configure device.\n", 1086 driver->driver_name); 1087 mutex_unlock(&dev->mutex); 1088 comedi_release_hardware_device(hardware_device); 1089 } else { 1090 /* 1091 * class_dev should be set properly here 1092 * after a successful auto config 1093 */ 1094 dev_info(dev->class_dev, 1095 "driver '%s' has successfully auto-configured '%s'.\n", 1096 driver->driver_name, dev->board_name); 1097 mutex_unlock(&dev->mutex); 1098 } 1099 return ret; 1100 } 1101 EXPORT_SYMBOL_GPL(comedi_auto_config); 1102 1103 /** 1104 * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device 1105 * @hardware_device: Hardware device previously passed to 1106 * comedi_auto_config(). 1107 * 1108 * Cleans up and eventually destroys the COMEDI device allocated by 1109 * comedi_auto_config() for the same hardware device. As part of this 1110 * clean-up, the low-level COMEDI driver's 'detach' handler will be called. 1111 * (The COMEDI device itself will persist in an unattached state if it is 1112 * still open, until it is released, and any mmapped buffers will persist 1113 * until they are munmapped.) 1114 * 1115 * This is usually called from a wrapper module in a bus-specific COMEDI 1116 * module, which in turn is usually set as the bus device 'remove' function 1117 * in the low-level COMEDI driver. 1118 */ 1119 void comedi_auto_unconfig(struct device *hardware_device) 1120 { 1121 if (!hardware_device) 1122 return; 1123 comedi_release_hardware_device(hardware_device); 1124 } 1125 EXPORT_SYMBOL_GPL(comedi_auto_unconfig); 1126 1127 /** 1128 * comedi_driver_register() - Register a low-level COMEDI driver 1129 * @driver: Low-level COMEDI driver. 1130 * 1131 * The low-level COMEDI driver is added to the list of registered COMEDI 1132 * drivers. This is used by the handler for the "/proc/comedi" file and is 1133 * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure 1134 * "legacy" COMEDI devices (for those low-level drivers that support it). 1135 * 1136 * Returns 0. 1137 */ 1138 int comedi_driver_register(struct comedi_driver *driver) 1139 { 1140 mutex_lock(&comedi_drivers_list_lock); 1141 driver->next = comedi_drivers; 1142 comedi_drivers = driver; 1143 mutex_unlock(&comedi_drivers_list_lock); 1144 1145 return 0; 1146 } 1147 EXPORT_SYMBOL_GPL(comedi_driver_register); 1148 1149 /** 1150 * comedi_driver_unregister() - Unregister a low-level COMEDI driver 1151 * @driver: Low-level COMEDI driver. 1152 * 1153 * The low-level COMEDI driver is removed from the list of registered COMEDI 1154 * drivers. Detaches any COMEDI devices attached to the driver, which will 1155 * result in the low-level driver's 'detach' handler being called for those 1156 * devices before this function returns. 1157 */ 1158 void comedi_driver_unregister(struct comedi_driver *driver) 1159 { 1160 struct comedi_driver *prev; 1161 int i; 1162 1163 /* unlink the driver */ 1164 mutex_lock(&comedi_drivers_list_lock); 1165 if (comedi_drivers == driver) { 1166 comedi_drivers = driver->next; 1167 } else { 1168 for (prev = comedi_drivers; prev->next; prev = prev->next) { 1169 if (prev->next == driver) { 1170 prev->next = driver->next; 1171 break; 1172 } 1173 } 1174 } 1175 mutex_unlock(&comedi_drivers_list_lock); 1176 1177 /* check for devices using this driver */ 1178 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { 1179 struct comedi_device *dev = comedi_dev_get_from_minor(i); 1180 1181 if (!dev) 1182 continue; 1183 1184 mutex_lock(&dev->mutex); 1185 if (dev->attached && dev->driver == driver) { 1186 if (dev->use_count) 1187 dev_warn(dev->class_dev, 1188 "BUG! detaching device with use_count=%d\n", 1189 dev->use_count); 1190 comedi_device_detach(dev); 1191 } 1192 mutex_unlock(&dev->mutex); 1193 comedi_dev_put(dev); 1194 } 1195 } 1196 EXPORT_SYMBOL_GPL(comedi_driver_unregister); 1197