drivers.c revision 6b362f5bea0dfbb648656041a92f6a00b298f558
1/* 2 module/drivers.c 3 functions for manipulating drivers 4 5 COMEDI - Linux Control and Measurement Device Interface 6 Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org> 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17*/ 18 19#include <linux/device.h> 20#include <linux/module.h> 21#include <linux/errno.h> 22#include <linux/kconfig.h> 23#include <linux/kernel.h> 24#include <linux/sched.h> 25#include <linux/fcntl.h> 26#include <linux/ioport.h> 27#include <linux/mm.h> 28#include <linux/slab.h> 29#include <linux/highmem.h> /* for SuSE brokenness */ 30#include <linux/vmalloc.h> 31#include <linux/cdev.h> 32#include <linux/dma-mapping.h> 33#include <linux/io.h> 34#include <linux/interrupt.h> 35#include <linux/firmware.h> 36 37#include "comedidev.h" 38#include "comedi_internal.h" 39 40struct comedi_driver *comedi_drivers; 41DEFINE_MUTEX(comedi_drivers_list_lock); 42 43int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev) 44{ 45 if (hw_dev == dev->hw_dev) 46 return 0; 47 if (dev->hw_dev != NULL) 48 return -EEXIST; 49 dev->hw_dev = get_device(hw_dev); 50 return 0; 51} 52EXPORT_SYMBOL_GPL(comedi_set_hw_dev); 53 54static void comedi_clear_hw_dev(struct comedi_device *dev) 55{ 56 put_device(dev->hw_dev); 57 dev->hw_dev = NULL; 58} 59 60/** 61 * comedi_alloc_devpriv() - Allocate memory for the device private data. 62 * @dev: comedi_device struct 63 * @size: size of the memory to allocate 64 */ 65void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size) 66{ 67 dev->private = kzalloc(size, GFP_KERNEL); 68 return dev->private; 69} 70EXPORT_SYMBOL_GPL(comedi_alloc_devpriv); 71 72int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices) 73{ 74 struct comedi_subdevice *s; 75 int i; 76 77 if (num_subdevices < 1) 78 return -EINVAL; 79 80 s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL); 81 if (!s) 82 return -ENOMEM; 83 dev->subdevices = s; 84 dev->n_subdevices = num_subdevices; 85 86 for (i = 0; i < num_subdevices; ++i) { 87 s = &dev->subdevices[i]; 88 s->device = dev; 89 s->index = i; 90 s->async_dma_dir = DMA_NONE; 91 spin_lock_init(&s->spin_lock); 92 s->minor = -1; 93 } 94 return 0; 95} 96EXPORT_SYMBOL_GPL(comedi_alloc_subdevices); 97 98static void comedi_device_detach_cleanup(struct comedi_device *dev) 99{ 100 int i; 101 struct comedi_subdevice *s; 102 103 if (dev->subdevices) { 104 for (i = 0; i < dev->n_subdevices; i++) { 105 s = &dev->subdevices[i]; 106 if (s->runflags & SRF_FREE_SPRIV) 107 kfree(s->private); 108 comedi_free_subdevice_minor(s); 109 if (s->async) { 110 comedi_buf_alloc(dev, s, 0); 111 kfree(s->async); 112 } 113 } 114 kfree(dev->subdevices); 115 dev->subdevices = NULL; 116 dev->n_subdevices = 0; 117 } 118 kfree(dev->private); 119 dev->private = NULL; 120 dev->driver = NULL; 121 dev->board_name = NULL; 122 dev->board_ptr = NULL; 123 dev->iobase = 0; 124 dev->iolen = 0; 125 dev->ioenabled = false; 126 dev->irq = 0; 127 dev->read_subdev = NULL; 128 dev->write_subdev = NULL; 129 dev->open = NULL; 130 dev->close = NULL; 131 comedi_clear_hw_dev(dev); 132} 133 134void comedi_device_detach(struct comedi_device *dev) 135{ 136 comedi_device_cancel_all(dev); 137 down_write(&dev->attach_lock); 138 dev->attached = false; 139 dev->detach_count++; 140 if (dev->driver) 141 dev->driver->detach(dev); 142 comedi_device_detach_cleanup(dev); 143 up_write(&dev->attach_lock); 144} 145 146static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) 147{ 148 return -EINVAL; 149} 150 151int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, 152 struct comedi_insn *insn, unsigned int *data) 153{ 154 return -EINVAL; 155} 156 157/** 158 * comedi_timeout() - busy-wait for a driver condition to occur. 159 * @dev: comedi_device struct 160 * @s: comedi_subdevice struct 161 * @insn: comedi_insn struct 162 * @cb: callback to check for the condition 163 * @context: private context from the driver 164 */ 165int comedi_timeout(struct comedi_device *dev, 166 struct comedi_subdevice *s, 167 struct comedi_insn *insn, 168 int (*cb)(struct comedi_device *dev, 169 struct comedi_subdevice *s, 170 struct comedi_insn *insn, 171 unsigned long context), 172 unsigned long context) 173{ 174 unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS); 175 int ret; 176 177 while (time_before(jiffies, timeout)) { 178 ret = cb(dev, s, insn, context); 179 if (ret != -EBUSY) 180 return ret; /* success (0) or non EBUSY errno */ 181 cpu_relax(); 182 } 183 return -ETIMEDOUT; 184} 185EXPORT_SYMBOL_GPL(comedi_timeout); 186 187/** 188 * comedi_dio_insn_config() - boilerplate (*insn_config) for DIO subdevices. 189 * @dev: comedi_device struct 190 * @s: comedi_subdevice struct 191 * @insn: comedi_insn struct 192 * @data: parameters for the @insn 193 * @mask: io_bits mask for grouped channels 194 */ 195int comedi_dio_insn_config(struct comedi_device *dev, 196 struct comedi_subdevice *s, 197 struct comedi_insn *insn, 198 unsigned int *data, 199 unsigned int mask) 200{ 201 unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec); 202 203 if (!mask) 204 mask = chan_mask; 205 206 switch (data[0]) { 207 case INSN_CONFIG_DIO_INPUT: 208 s->io_bits &= ~mask; 209 break; 210 211 case INSN_CONFIG_DIO_OUTPUT: 212 s->io_bits |= mask; 213 break; 214 215 case INSN_CONFIG_DIO_QUERY: 216 data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT; 217 return insn->n; 218 219 default: 220 return -EINVAL; 221 } 222 223 return 0; 224} 225EXPORT_SYMBOL_GPL(comedi_dio_insn_config); 226 227/** 228 * comedi_dio_update_state() - update the internal state of DIO subdevices. 229 * @s: comedi_subdevice struct 230 * @data: the channel mask and bits to update 231 */ 232unsigned int comedi_dio_update_state(struct comedi_subdevice *s, 233 unsigned int *data) 234{ 235 unsigned int chanmask = (s->n_chan < 32) ? ((1 << s->n_chan) - 1) 236 : 0xffffffff; 237 unsigned int mask = data[0] & chanmask; 238 unsigned int bits = data[1]; 239 240 if (mask) { 241 s->state &= ~mask; 242 s->state |= (bits & mask); 243 } 244 245 return mask; 246} 247EXPORT_SYMBOL_GPL(comedi_dio_update_state); 248 249static int insn_rw_emulate_bits(struct comedi_device *dev, 250 struct comedi_subdevice *s, 251 struct comedi_insn *insn, unsigned int *data) 252{ 253 struct comedi_insn new_insn; 254 int ret; 255 static const unsigned channels_per_bitfield = 32; 256 257 unsigned chan = CR_CHAN(insn->chanspec); 258 const unsigned base_bitfield_channel = 259 (chan < channels_per_bitfield) ? 0 : chan; 260 unsigned int new_data[2]; 261 262 memset(new_data, 0, sizeof(new_data)); 263 memset(&new_insn, 0, sizeof(new_insn)); 264 new_insn.insn = INSN_BITS; 265 new_insn.chanspec = base_bitfield_channel; 266 new_insn.n = 2; 267 new_insn.subdev = insn->subdev; 268 269 if (insn->insn == INSN_WRITE) { 270 if (!(s->subdev_flags & SDF_WRITABLE)) 271 return -EINVAL; 272 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */ 273 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel)) 274 : 0; /* bits */ 275 } 276 277 ret = s->insn_bits(dev, s, &new_insn, new_data); 278 if (ret < 0) 279 return ret; 280 281 if (insn->insn == INSN_READ) 282 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1; 283 284 return 1; 285} 286 287static int __comedi_device_postconfig_async(struct comedi_device *dev, 288 struct comedi_subdevice *s) 289{ 290 struct comedi_async *async; 291 unsigned int buf_size; 292 int ret; 293 294 if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) { 295 dev_warn(dev->class_dev, 296 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n"); 297 return -EINVAL; 298 } 299 if (!s->do_cmdtest) { 300 dev_warn(dev->class_dev, 301 "async subdevices must have a do_cmdtest() function\n"); 302 return -EINVAL; 303 } 304 305 async = kzalloc(sizeof(*async), GFP_KERNEL); 306 if (!async) 307 return -ENOMEM; 308 309 init_waitqueue_head(&async->wait_head); 310 s->async = async; 311 312 async->max_bufsize = comedi_default_buf_maxsize_kb * 1024; 313 buf_size = comedi_default_buf_size_kb * 1024; 314 if (buf_size > async->max_bufsize) 315 buf_size = async->max_bufsize; 316 317 if (comedi_buf_alloc(dev, s, buf_size) < 0) { 318 dev_warn(dev->class_dev, "Buffer allocation failed\n"); 319 return -ENOMEM; 320 } 321 if (s->buf_change) { 322 ret = s->buf_change(dev, s, buf_size); 323 if (ret < 0) 324 return ret; 325 } 326 327 comedi_alloc_subdevice_minor(s); 328 329 return 0; 330} 331 332static int __comedi_device_postconfig(struct comedi_device *dev) 333{ 334 struct comedi_subdevice *s; 335 int ret; 336 int i; 337 338 for (i = 0; i < dev->n_subdevices; i++) { 339 s = &dev->subdevices[i]; 340 341 if (s->type == COMEDI_SUBD_UNUSED) 342 continue; 343 344 if (s->type == COMEDI_SUBD_DO) { 345 if (s->n_chan < 32) 346 s->io_bits = (1 << s->n_chan) - 1; 347 else 348 s->io_bits = 0xffffffff; 349 } 350 351 if (s->len_chanlist == 0) 352 s->len_chanlist = 1; 353 354 if (s->do_cmd) { 355 ret = __comedi_device_postconfig_async(dev, s); 356 if (ret) 357 return ret; 358 } 359 360 if (!s->range_table && !s->range_table_list) 361 s->range_table = &range_unknown; 362 363 if (!s->insn_read && s->insn_bits) 364 s->insn_read = insn_rw_emulate_bits; 365 if (!s->insn_write && s->insn_bits) 366 s->insn_write = insn_rw_emulate_bits; 367 368 if (!s->insn_read) 369 s->insn_read = insn_inval; 370 if (!s->insn_write) 371 s->insn_write = insn_inval; 372 if (!s->insn_bits) 373 s->insn_bits = insn_inval; 374 if (!s->insn_config) 375 s->insn_config = insn_inval; 376 377 if (!s->poll) 378 s->poll = poll_invalid; 379 } 380 381 return 0; 382} 383 384/* do a little post-config cleanup */ 385static int comedi_device_postconfig(struct comedi_device *dev) 386{ 387 int ret; 388 389 ret = __comedi_device_postconfig(dev); 390 if (ret < 0) 391 return ret; 392 down_write(&dev->attach_lock); 393 dev->attached = true; 394 up_write(&dev->attach_lock); 395 return 0; 396} 397 398/* 399 * Generic recognize function for drivers that register their supported 400 * board names. 401 * 402 * 'driv->board_name' points to a 'const char *' member within the 403 * zeroth element of an array of some private board information 404 * structure, say 'struct foo_board' containing a member 'const char 405 * *board_name' that is initialized to point to a board name string that 406 * is one of the candidates matched against this function's 'name' 407 * parameter. 408 * 409 * 'driv->offset' is the size of the private board information 410 * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is 411 * the length of the array of private board information structures. 412 * 413 * If one of the board names in the array of private board information 414 * structures matches the name supplied to this function, the function 415 * returns a pointer to the pointer to the board name, otherwise it 416 * returns NULL. The return value ends up in the 'board_ptr' member of 417 * a 'struct comedi_device' that the low-level comedi driver's 418 * 'attach()' hook can convert to a point to a particular element of its 419 * array of private board information structures by subtracting the 420 * offset of the member that points to the board name. (No subtraction 421 * is required if the board name pointer is the first member of the 422 * private board information structure, which is generally the case.) 423 */ 424static void *comedi_recognize(struct comedi_driver *driv, const char *name) 425{ 426 char **name_ptr = (char **)driv->board_name; 427 int i; 428 429 for (i = 0; i < driv->num_names; i++) { 430 if (strcmp(*name_ptr, name) == 0) 431 return name_ptr; 432 name_ptr = (void *)name_ptr + driv->offset; 433 } 434 435 return NULL; 436} 437 438static void comedi_report_boards(struct comedi_driver *driv) 439{ 440 unsigned int i; 441 const char *const *name_ptr; 442 443 pr_info("comedi: valid board names for %s driver are:\n", 444 driv->driver_name); 445 446 name_ptr = driv->board_name; 447 for (i = 0; i < driv->num_names; i++) { 448 pr_info(" %s\n", *name_ptr); 449 name_ptr = (const char **)((char *)name_ptr + driv->offset); 450 } 451 452 if (driv->num_names == 0) 453 pr_info(" %s\n", driv->driver_name); 454} 455 456/** 457 * comedi_load_firmware() - Request and load firmware for a device. 458 * @dev: comedi_device struct 459 * @hw_device: device struct for the comedi_device 460 * @name: the name of the firmware image 461 * @cb: callback to the upload the firmware image 462 * @context: private context from the driver 463 */ 464int comedi_load_firmware(struct comedi_device *dev, 465 struct device *device, 466 const char *name, 467 int (*cb)(struct comedi_device *dev, 468 const u8 *data, size_t size, 469 unsigned long context), 470 unsigned long context) 471{ 472 const struct firmware *fw; 473 int ret; 474 475 if (!cb) 476 return -EINVAL; 477 478 ret = request_firmware(&fw, name, device); 479 if (ret == 0) { 480 ret = cb(dev, fw->data, fw->size, context); 481 release_firmware(fw); 482 } 483 484 return ret < 0 ? ret : 0; 485} 486EXPORT_SYMBOL_GPL(comedi_load_firmware); 487 488/** 489 * __comedi_request_region() - Request an I/O reqion for a legacy driver. 490 * @dev: comedi_device struct 491 * @start: base address of the I/O reqion 492 * @len: length of the I/O region 493 */ 494int __comedi_request_region(struct comedi_device *dev, 495 unsigned long start, unsigned long len) 496{ 497 if (!start) { 498 dev_warn(dev->class_dev, 499 "%s: a I/O base address must be specified\n", 500 dev->board_name); 501 return -EINVAL; 502 } 503 504 if (!request_region(start, len, dev->board_name)) { 505 dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n", 506 dev->board_name, start, len); 507 return -EIO; 508 } 509 510 return 0; 511} 512EXPORT_SYMBOL_GPL(__comedi_request_region); 513 514/** 515 * comedi_request_region() - Request an I/O reqion for a legacy driver. 516 * @dev: comedi_device struct 517 * @start: base address of the I/O reqion 518 * @len: length of the I/O region 519 */ 520int comedi_request_region(struct comedi_device *dev, 521 unsigned long start, unsigned long len) 522{ 523 int ret; 524 525 ret = __comedi_request_region(dev, start, len); 526 if (ret == 0) { 527 dev->iobase = start; 528 dev->iolen = len; 529 } 530 531 return ret; 532} 533EXPORT_SYMBOL_GPL(comedi_request_region); 534 535/** 536 * comedi_legacy_detach() - A generic (*detach) function for legacy drivers. 537 * @dev: comedi_device struct 538 */ 539void comedi_legacy_detach(struct comedi_device *dev) 540{ 541 if (dev->irq) { 542 free_irq(dev->irq, dev); 543 dev->irq = 0; 544 } 545 if (dev->iobase && dev->iolen) { 546 release_region(dev->iobase, dev->iolen); 547 dev->iobase = 0; 548 dev->iolen = 0; 549 } 550} 551EXPORT_SYMBOL_GPL(comedi_legacy_detach); 552 553int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) 554{ 555 struct comedi_driver *driv; 556 int ret; 557 558 if (dev->attached) 559 return -EBUSY; 560 561 mutex_lock(&comedi_drivers_list_lock); 562 for (driv = comedi_drivers; driv; driv = driv->next) { 563 if (!try_module_get(driv->module)) 564 continue; 565 if (driv->num_names) { 566 dev->board_ptr = comedi_recognize(driv, it->board_name); 567 if (dev->board_ptr) 568 break; 569 } else if (strcmp(driv->driver_name, it->board_name) == 0) 570 break; 571 module_put(driv->module); 572 } 573 if (driv == NULL) { 574 /* recognize has failed if we get here */ 575 /* report valid board names before returning error */ 576 for (driv = comedi_drivers; driv; driv = driv->next) { 577 if (!try_module_get(driv->module)) 578 continue; 579 comedi_report_boards(driv); 580 module_put(driv->module); 581 } 582 ret = -EIO; 583 goto out; 584 } 585 if (driv->attach == NULL) { 586 /* driver does not support manual configuration */ 587 dev_warn(dev->class_dev, 588 "driver '%s' does not support attach using comedi_config\n", 589 driv->driver_name); 590 module_put(driv->module); 591 ret = -ENOSYS; 592 goto out; 593 } 594 dev->driver = driv; 595 dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr 596 : dev->driver->driver_name; 597 ret = driv->attach(dev, it); 598 if (ret >= 0) 599 ret = comedi_device_postconfig(dev); 600 if (ret < 0) { 601 comedi_device_detach(dev); 602 module_put(driv->module); 603 } 604 /* On success, the driver module count has been incremented. */ 605out: 606 mutex_unlock(&comedi_drivers_list_lock); 607 return ret; 608} 609 610int comedi_auto_config(struct device *hardware_device, 611 struct comedi_driver *driver, unsigned long context) 612{ 613 struct comedi_device *dev; 614 int ret; 615 616 if (!hardware_device) { 617 pr_warn("BUG! comedi_auto_config called with NULL hardware_device\n"); 618 return -EINVAL; 619 } 620 if (!driver) { 621 dev_warn(hardware_device, 622 "BUG! comedi_auto_config called with NULL comedi driver\n"); 623 return -EINVAL; 624 } 625 626 if (!driver->auto_attach) { 627 dev_warn(hardware_device, 628 "BUG! comedi driver '%s' has no auto_attach handler\n", 629 driver->driver_name); 630 return -EINVAL; 631 } 632 633 dev = comedi_alloc_board_minor(hardware_device); 634 if (IS_ERR(dev)) { 635 dev_warn(hardware_device, 636 "driver '%s' could not create device.\n", 637 driver->driver_name); 638 return PTR_ERR(dev); 639 } 640 /* Note: comedi_alloc_board_minor() locked dev->mutex. */ 641 642 dev->driver = driver; 643 dev->board_name = dev->driver->driver_name; 644 ret = driver->auto_attach(dev, context); 645 if (ret >= 0) 646 ret = comedi_device_postconfig(dev); 647 mutex_unlock(&dev->mutex); 648 649 if (ret < 0) { 650 dev_warn(hardware_device, 651 "driver '%s' failed to auto-configure device.\n", 652 driver->driver_name); 653 comedi_release_hardware_device(hardware_device); 654 } else { 655 /* 656 * class_dev should be set properly here 657 * after a successful auto config 658 */ 659 dev_info(dev->class_dev, 660 "driver '%s' has successfully auto-configured '%s'.\n", 661 driver->driver_name, dev->board_name); 662 } 663 return ret; 664} 665EXPORT_SYMBOL_GPL(comedi_auto_config); 666 667void comedi_auto_unconfig(struct device *hardware_device) 668{ 669 if (hardware_device == NULL) 670 return; 671 comedi_release_hardware_device(hardware_device); 672} 673EXPORT_SYMBOL_GPL(comedi_auto_unconfig); 674 675int comedi_driver_register(struct comedi_driver *driver) 676{ 677 mutex_lock(&comedi_drivers_list_lock); 678 driver->next = comedi_drivers; 679 comedi_drivers = driver; 680 mutex_unlock(&comedi_drivers_list_lock); 681 682 return 0; 683} 684EXPORT_SYMBOL_GPL(comedi_driver_register); 685 686void comedi_driver_unregister(struct comedi_driver *driver) 687{ 688 struct comedi_driver *prev; 689 int i; 690 691 /* unlink the driver */ 692 mutex_lock(&comedi_drivers_list_lock); 693 if (comedi_drivers == driver) { 694 comedi_drivers = driver->next; 695 } else { 696 for (prev = comedi_drivers; prev->next; prev = prev->next) { 697 if (prev->next == driver) { 698 prev->next = driver->next; 699 break; 700 } 701 } 702 } 703 mutex_unlock(&comedi_drivers_list_lock); 704 705 /* check for devices using this driver */ 706 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { 707 struct comedi_device *dev = comedi_dev_get_from_minor(i); 708 709 if (!dev) 710 continue; 711 712 mutex_lock(&dev->mutex); 713 if (dev->attached && dev->driver == driver) { 714 if (dev->use_count) 715 dev_warn(dev->class_dev, 716 "BUG! detaching device with use_count=%d\n", 717 dev->use_count); 718 comedi_device_detach(dev); 719 } 720 mutex_unlock(&dev->mutex); 721 comedi_dev_put(dev); 722 } 723} 724EXPORT_SYMBOL_GPL(comedi_driver_unregister); 725