drivers/staging/comedi/drivers.c

   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
  40 struct comedi_driver *comedi_drivers;
  41 DEFINE_MUTEX(comedi_drivers_list_lock);
  42
  43 int 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 }
  52 EXPORT_SYMBOL_GPL(comedi_set_hw_dev);
  53
  54 static 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  */
  65 void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size)
  66 {
  67         dev->private = kzalloc(size, GFP_KERNEL);
  68         return dev->private;
  69 }
  70 EXPORT_SYMBOL_GPL(comedi_alloc_devpriv);
  71
  72 int 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 }
  96 EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);
  97
  98 static void cleanup_device(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
 134 void comedi_device_detach(struct comedi_device *dev)
 135 {
 136         dev->attached = false;
 137         if (dev->driver)
 138                 dev->driver->detach(dev);
 139         cleanup_device(dev);
 140 }
 141
 142 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
 143 {
 144         return -EINVAL;
 145 }
 146
 147 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
 148                struct comedi_insn *insn, unsigned int *data)
 149 {
 150         return -EINVAL;
 151 }
 152
 153 /**
 154  * comedi_dio_insn_config() - boilerplate (*insn_config) for DIO subdevices.
 155  * @dev: comedi_device struct
 156  * @s: comedi_subdevice struct
 157  * @insn: comedi_insn struct
 158  * @data: parameters for the @insn
 159  * @mask: io_bits mask for grouped channels
 160  */
 161 int comedi_dio_insn_config(struct comedi_device *dev,
 162                            struct comedi_subdevice *s,
 163                            struct comedi_insn *insn,
 164                            unsigned int *data,
 165                            unsigned int mask)
 166 {
 167         unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec);
 168
 169         if (!mask)
 170                 mask = chan_mask;
 171
 172         switch (data[0]) {
 173         case INSN_CONFIG_DIO_INPUT:
 174                 s->io_bits &= ~mask;
 175                 break;
 176
 177         case INSN_CONFIG_DIO_OUTPUT:
 178                 s->io_bits |= mask;
 179                 break;
 180
 181         case INSN_CONFIG_DIO_QUERY:
 182                 data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT;
 183                 return insn->n;
 184
 185         default:
 186                 return -EINVAL;
 187         }
 188
 189         return 0;
 190 }
 191 EXPORT_SYMBOL_GPL(comedi_dio_insn_config);
 192
 193 /**
 194  * comedi_dio_update_state() - update the internal state of DIO subdevices.
 195  * @s: comedi_subdevice struct
 196  * @data: the channel mask and bits to update
 197  */
 198 unsigned int comedi_dio_update_state(struct comedi_subdevice *s,
 199                                      unsigned int *data)
 200 {
 201         unsigned int chanmask = (s->n_chan < 32) ? ((1 << s->n_chan) - 1)
 202                                                  : 0xffffffff;
 203         unsigned int mask = data[0] & chanmask;
 204         unsigned int bits = data[1];
 205
 206         if (mask) {
 207                 s->state &= ~mask;
 208                 s->state |= (bits & mask);
 209         }
 210
 211         return mask;
 212 }
 213 EXPORT_SYMBOL_GPL(comedi_dio_update_state);
 214
 215 static int insn_rw_emulate_bits(struct comedi_device *dev,
 216                                 struct comedi_subdevice *s,
 217                                 struct comedi_insn *insn, unsigned int *data)
 218 {
 219         struct comedi_insn new_insn;
 220         int ret;
 221         static const unsigned channels_per_bitfield = 32;
 222
 223         unsigned chan = CR_CHAN(insn->chanspec);
 224         const unsigned base_bitfield_channel =
 225             (chan < channels_per_bitfield) ? 0 : chan;
 226         unsigned int new_data[2];
 227         memset(new_data, 0, sizeof(new_data));
 228         memset(&new_insn, 0, sizeof(new_insn));
 229         new_insn.insn = INSN_BITS;
 230         new_insn.chanspec = base_bitfield_channel;
 231         new_insn.n = 2;
 232         new_insn.subdev = insn->subdev;
 233
 234         if (insn->insn == INSN_WRITE) {
 235                 if (!(s->subdev_flags & SDF_WRITABLE))
 236                         return -EINVAL;
 237                 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
 238                 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
 239                               : 0; /* bits */
 240         }
 241
 242         ret = s->insn_bits(dev, s, &new_insn, new_data);
 243         if (ret < 0)
 244                 return ret;
 245
 246         if (insn->insn == INSN_READ)
 247                 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
 248
 249         return 1;
 250 }
 251
 252 static int __comedi_device_postconfig_async(struct comedi_device *dev,
 253                                             struct comedi_subdevice *s)
 254 {
 255         struct comedi_async *async;
 256         unsigned int buf_size;
 257         int ret;
 258
 259         if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {
 260                 dev_warn(dev->class_dev,
 261                          "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");
 262                 return -EINVAL;
 263         }
 264         if (!s->do_cmdtest) {
 265                 dev_warn(dev->class_dev,
 266                          "async subdevices must have a do_cmdtest() function\n");
 267                 return -EINVAL;
 268         }
 269
 270         async = kzalloc(sizeof(*async), GFP_KERNEL);
 271         if (!async)
 272                 return -ENOMEM;
 273
 274         init_waitqueue_head(&async->wait_head);
 275         async->subdevice = s;
 276         s->async = async;
 277
 278         async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
 279         buf_size = comedi_default_buf_size_kb * 1024;
 280         if (buf_size > async->max_bufsize)
 281                 buf_size = async->max_bufsize;
 282
 283         if (comedi_buf_alloc(dev, s, buf_size) < 0) {
 284                 dev_warn(dev->class_dev, "Buffer allocation failed\n");
 285                 return -ENOMEM;
 286         }
 287         if (s->buf_change) {
 288                 ret = s->buf_change(dev, s, buf_size);
 289                 if (ret < 0)
 290                         return ret;
 291         }
 292
 293         comedi_alloc_subdevice_minor(s);
 294
 295         return 0;
 296 }
 297
 298 static int __comedi_device_postconfig(struct comedi_device *dev)
 299 {
 300         struct comedi_subdevice *s;
 301         int ret;
 302         int i;
 303
 304         for (i = 0; i < dev->n_subdevices; i++) {
 305                 s = &dev->subdevices[i];
 306
 307                 if (s->type == COMEDI_SUBD_UNUSED)
 308                         continue;
 309
 310                 if (s->type == COMEDI_SUBD_DO) {
 311                         if (s->n_chan < 32)
 312                                 s->io_bits = (1 << s->n_chan) - 1;
 313                         else
 314                                 s->io_bits = 0xffffffff;
 315                 }
 316
 317                 if (s->len_chanlist == 0)
 318                         s->len_chanlist = 1;
 319
 320                 if (s->do_cmd) {
 321                         ret = __comedi_device_postconfig_async(dev, s);
 322                         if (ret)
 323                                 return ret;
 324                 }
 325
 326                 if (!s->range_table && !s->range_table_list)
 327                         s->range_table = &range_unknown;
 328
 329                 if (!s->insn_read && s->insn_bits)
 330                         s->insn_read = insn_rw_emulate_bits;
 331                 if (!s->insn_write && s->insn_bits)
 332                         s->insn_write = insn_rw_emulate_bits;
 333
 334                 if (!s->insn_read)
 335                         s->insn_read = insn_inval;
 336                 if (!s->insn_write)
 337                         s->insn_write = insn_inval;
 338                 if (!s->insn_bits)
 339                         s->insn_bits = insn_inval;
 340                 if (!s->insn_config)
 341                         s->insn_config = insn_inval;
 342
 343                 if (!s->poll)
 344                         s->poll = poll_invalid;
 345         }
 346
 347         return 0;
 348 }
 349
 350 /* do a little post-config cleanup */
 351 static int comedi_device_postconfig(struct comedi_device *dev)
 352 {
 353         int ret;
 354
 355         ret = __comedi_device_postconfig(dev);
 356         if (ret < 0)
 357                 return ret;
 358         smp_wmb();
 359         dev->attached = true;
 360         return 0;
 361 }
 362
 363 /*
 364  * Generic recognize function for drivers that register their supported
 365  * board names.
 366  *
 367  * 'driv->board_name' points to a 'const char *' member within the
 368  * zeroth element of an array of some private board information
 369  * structure, say 'struct foo_board' containing a member 'const char
 370  * *board_name' that is initialized to point to a board name string that
 371  * is one of the candidates matched against this function's 'name'
 372  * parameter.
 373  *
 374  * 'driv->offset' is the size of the private board information
 375  * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is
 376  * the length of the array of private board information structures.
 377  *
 378  * If one of the board names in the array of private board information
 379  * structures matches the name supplied to this function, the function
 380  * returns a pointer to the pointer to the board name, otherwise it
 381  * returns NULL.  The return value ends up in the 'board_ptr' member of
 382  * a 'struct comedi_device' that the low-level comedi driver's
 383  * 'attach()' hook can convert to a point to a particular element of its
 384  * array of private board information structures by subtracting the
 385  * offset of the member that points to the board name.  (No subtraction
 386  * is required if the board name pointer is the first member of the
 387  * private board information structure, which is generally the case.)
 388  */
 389 static void *comedi_recognize(struct comedi_driver *driv, const char *name)
 390 {
 391         char **name_ptr = (char **)driv->board_name;
 392         int i;
 393
 394         for (i = 0; i < driv->num_names; i++) {
 395                 if (strcmp(*name_ptr, name) == 0)
 396                         return name_ptr;
 397                 name_ptr = (void *)name_ptr + driv->offset;
 398         }
 399
 400         return NULL;
 401 }
 402
 403 static void comedi_report_boards(struct comedi_driver *driv)
 404 {
 405         unsigned int i;
 406         const char *const *name_ptr;
 407
 408         pr_info("comedi: valid board names for %s driver are:\n",
 409                 driv->driver_name);
 410
 411         name_ptr = driv->board_name;
 412         for (i = 0; i < driv->num_names; i++) {
 413                 pr_info(" %s\n", *name_ptr);
 414                 name_ptr = (const char **)((char *)name_ptr + driv->offset);
 415         }
 416
 417         if (driv->num_names == 0)
 418                 pr_info(" %s\n", driv->driver_name);
 419 }
 420
 421 /**
 422  * comedi_load_firmware() - Request and load firmware for a device.
 423  * @dev: comedi_device struct
 424  * @hw_device: device struct for the comedi_device
 425  * @name: the name of the firmware image
 426  * @cb: callback to the upload the firmware image
 427  * @context: private context from the driver
 428  */
 429 int comedi_load_firmware(struct comedi_device *dev,
 430                          struct device *device,
 431                          const char *name,
 432                          int (*cb)(struct comedi_device *dev,
 433                                    const u8 *data, size_t size,
 434                                    unsigned long context),
 435                          unsigned long context)
 436 {
 437         const struct firmware *fw;
 438         int ret;
 439
 440         if (!cb)
 441                 return -EINVAL;
 442
 443         ret = request_firmware(&fw, name, device);
 444         if (ret == 0) {
 445                 ret = cb(dev, fw->data, fw->size, context);
 446                 release_firmware(fw);
 447         }
 448
 449         return ret;
 450 }
 451 EXPORT_SYMBOL_GPL(comedi_load_firmware);
 452
 453 /**
 454  * __comedi_request_region() - Request an I/O reqion for a legacy driver.
 455  * @dev: comedi_device struct
 456  * @start: base address of the I/O reqion
 457  * @len: length of the I/O region
 458  */
 459 int __comedi_request_region(struct comedi_device *dev,
 460                             unsigned long start, unsigned long len)
 461 {
 462         if (!start) {
 463                 dev_warn(dev->class_dev,
 464                          "%s: a I/O base address must be specified\n",
 465                          dev->board_name);
 466                 return -EINVAL;
 467         }
 468
 469         if (!request_region(start, len, dev->board_name)) {
 470                 dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n",
 471                          dev->board_name, start, len);
 472                 return -EIO;
 473         }
 474
 475         return 0;
 476 }
 477 EXPORT_SYMBOL_GPL(__comedi_request_region);
 478
 479 /**
 480  * comedi_request_region() - Request an I/O reqion for a legacy driver.
 481  * @dev: comedi_device struct
 482  * @start: base address of the I/O reqion
 483  * @len: length of the I/O region
 484  */
 485 int comedi_request_region(struct comedi_device *dev,
 486                           unsigned long start, unsigned long len)
 487 {
 488         int ret;
 489
 490         ret = __comedi_request_region(dev, start, len);
 491         if (ret == 0) {
 492                 dev->iobase = start;
 493                 dev->iolen = len;
 494         }
 495
 496         return ret;
 497 }
 498 EXPORT_SYMBOL_GPL(comedi_request_region);
 499
 500 /**
 501  * comedi_legacy_detach() - A generic (*detach) function for legacy drivers.
 502  * @dev: comedi_device struct
 503  */
 504 void comedi_legacy_detach(struct comedi_device *dev)
 505 {
 506         if (dev->irq) {
 507                 free_irq(dev->irq, dev);
 508                 dev->irq = 0;
 509         }
 510         if (dev->iobase && dev->iolen) {
 511                 release_region(dev->iobase, dev->iolen);
 512                 dev->iobase = 0;
 513                 dev->iolen = 0;
 514         }
 515 }
 516 EXPORT_SYMBOL_GPL(comedi_legacy_detach);
 517
 518 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 519 {
 520         struct comedi_driver *driv;
 521         int ret;
 522
 523         if (dev->attached)
 524                 return -EBUSY;
 525
 526         mutex_lock(&comedi_drivers_list_lock);
 527         for (driv = comedi_drivers; driv; driv = driv->next) {
 528                 if (!try_module_get(driv->module))
 529                         continue;
 530                 if (driv->num_names) {
 531                         dev->board_ptr = comedi_recognize(driv, it->board_name);
 532                         if (dev->board_ptr)
 533                                 break;
 534                 } else if (strcmp(driv->driver_name, it->board_name) == 0)
 535                         break;
 536                 module_put(driv->module);
 537         }
 538         if (driv == NULL) {
 539                 /*  recognize has failed if we get here */
 540                 /*  report valid board names before returning error */
 541                 for (driv = comedi_drivers; driv; driv = driv->next) {
 542                         if (!try_module_get(driv->module))
 543                                 continue;
 544                         comedi_report_boards(driv);
 545                         module_put(driv->module);
 546                 }
 547                 ret = -EIO;
 548                 goto out;
 549         }
 550         if (driv->attach == NULL) {
 551                 /* driver does not support manual configuration */
 552                 dev_warn(dev->class_dev,
 553                          "driver '%s' does not support attach using comedi_config\n",
 554                          driv->driver_name);
 555                 module_put(driv->module);
 556                 ret = -ENOSYS;
 557                 goto out;
 558         }
 559         /* initialize dev->driver here so
 560          * comedi_error() can be called from attach */
 561         dev->driver = driv;
 562         dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr
 563                                          : dev->driver->driver_name;
 564         ret = driv->attach(dev, it);
 565         if (ret >= 0)
 566                 ret = comedi_device_postconfig(dev);
 567         if (ret < 0) {
 568                 comedi_device_detach(dev);
 569                 module_put(driv->module);
 570         }
 571         /* On success, the driver module count has been incremented. */
 572 out:
 573         mutex_unlock(&comedi_drivers_list_lock);
 574         return ret;
 575 }
 576
 577 int comedi_auto_config(struct device *hardware_device,
 578                        struct comedi_driver *driver, unsigned long context)
 579 {
 580         struct comedi_device *dev;
 581         int ret;
 582
 583         if (!hardware_device) {
 584                 pr_warn("BUG! comedi_auto_config called with NULL hardware_device\n");
 585                 return -EINVAL;
 586         }
 587         if (!driver) {
 588                 dev_warn(hardware_device,
 589                          "BUG! comedi_auto_config called with NULL comedi driver\n");
 590                 return -EINVAL;
 591         }
 592
 593         if (!driver->auto_attach) {
 594                 dev_warn(hardware_device,
 595                          "BUG! comedi driver '%s' has no auto_attach handler\n",
 596                          driver->driver_name);
 597                 return -EINVAL;
 598         }
 599
 600         dev = comedi_alloc_board_minor(hardware_device);
 601         if (IS_ERR(dev))
 602                 return PTR_ERR(dev);
 603         /* Note: comedi_alloc_board_minor() locked dev->mutex. */
 604
 605         dev->driver = driver;
 606         dev->board_name = dev->driver->driver_name;
 607         ret = driver->auto_attach(dev, context);
 608         if (ret >= 0)
 609                 ret = comedi_device_postconfig(dev);
 610         if (ret < 0)
 611                 comedi_device_detach(dev);
 612         mutex_unlock(&dev->mutex);
 613
 614         if (ret < 0)
 615                 comedi_release_hardware_device(hardware_device);
 616         return ret;
 617 }
 618 EXPORT_SYMBOL_GPL(comedi_auto_config);
 619
 620 void comedi_auto_unconfig(struct device *hardware_device)
 621 {
 622         if (hardware_device == NULL)
 623                 return;
 624         comedi_release_hardware_device(hardware_device);
 625 }
 626 EXPORT_SYMBOL_GPL(comedi_auto_unconfig);
 627
 628 int comedi_driver_register(struct comedi_driver *driver)
 629 {
 630         mutex_lock(&comedi_drivers_list_lock);
 631         driver->next = comedi_drivers;
 632         comedi_drivers = driver;
 633         mutex_unlock(&comedi_drivers_list_lock);
 634
 635         return 0;
 636 }
 637 EXPORT_SYMBOL_GPL(comedi_driver_register);
 638
 639 void comedi_driver_unregister(struct comedi_driver *driver)
 640 {
 641         struct comedi_driver *prev;
 642         int i;
 643
 644         /* unlink the driver */
 645         mutex_lock(&comedi_drivers_list_lock);
 646         if (comedi_drivers == driver) {
 647                 comedi_drivers = driver->next;
 648         } else {
 649                 for (prev = comedi_drivers; prev->next; prev = prev->next) {
 650                         if (prev->next == driver) {
 651                                 prev->next = driver->next;
 652                                 break;
 653                         }
 654                 }
 655         }
 656         mutex_unlock(&comedi_drivers_list_lock);
 657
 658         /* check for devices using this driver */
 659         for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
 660                 struct comedi_device *dev = comedi_dev_from_minor(i);
 661
 662                 if (!dev)
 663                         continue;
 664
 665                 mutex_lock(&dev->mutex);
 666                 if (dev->attached && dev->driver == driver) {
 667                         if (dev->use_count)
 668                                 dev_warn(dev->class_dev,
 669                                          "BUG! detaching device with use_count=%d\n",
 670                                          dev->use_count);
 671                         comedi_device_detach(dev);
 672                 }
 673                 mutex_unlock(&dev->mutex);
 674         }
 675 }
 676 EXPORT_SYMBOL_GPL(comedi_driver_unregister);