skel.c revision 828684f9a6e096f9150bad523c43b75d74b9badd
1/* 2 comedi/drivers/skel.c 3 Skeleton code for a Comedi driver 4 5 COMEDI - Linux Control and Measurement Device Interface 6 Copyright (C) 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 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 21 22*/ 23/* 24Driver: skel 25Description: Skeleton driver, an example for driver writers 26Devices: 27Author: ds 28Updated: Mon, 18 Mar 2002 15:34:01 -0800 29Status: works 30 31This driver is a documented example on how Comedi drivers are 32written. 33 34Configuration Options: 35 none 36*/ 37 38/* 39 * The previous block comment is used to automatically generate 40 * documentation in Comedi and Comedilib. The fields: 41 * 42 * Driver: the name of the driver 43 * Description: a short phrase describing the driver. Don't list boards. 44 * Devices: a full list of the boards that attempt to be supported by 45 * the driver. Format is "(manufacturer) board name [comedi name]", 46 * where comedi_name is the name that is used to configure the board. 47 * See the comment near board_name: in the struct comedi_driver structure 48 * below. If (manufacturer) or [comedi name] is missing, the previous 49 * value is used. 50 * Author: you 51 * Updated: date when the _documentation_ was last updated. Use 'date -R' 52 * to get a value for this. 53 * Status: a one-word description of the status. Valid values are: 54 * works - driver works correctly on most boards supported, and 55 * passes comedi_test. 56 * unknown - unknown. Usually put there by ds. 57 * experimental - may not work in any particular release. Author 58 * probably wants assistance testing it. 59 * bitrotten - driver has not been update in a long time, probably 60 * doesn't work, and probably is missing support for significant 61 * Comedi interface features. 62 * untested - author probably wrote it "blind", and is believed to 63 * work, but no confirmation. 64 * 65 * These headers should be followed by a blank line, and any comments 66 * you wish to say about the driver. The comment area is the place 67 * to put any known bugs, limitations, unsupported features, supported 68 * command triggers, whether or not commands are supported on particular 69 * subdevices, etc. 70 * 71 * Somewhere in the comment should be information about configuration 72 * options that are used with comedi_config. 73 */ 74 75#include "../comedidev.h" 76 77#include <linux/pci.h> /* for PCI devices */ 78 79/* Imaginary registers for the imaginary board */ 80 81#define SKEL_SIZE 0 82 83#define SKEL_START_AI_CONV 0 84#define SKEL_AI_READ 0 85 86/* 87 * Board descriptions for two imaginary boards. Describing the 88 * boards in this way is optional, and completely driver-dependent. 89 * Some drivers use arrays such as this, other do not. 90 */ 91struct skel_board { 92 const char *name; 93 int ai_chans; 94 int ai_bits; 95 int have_dio; 96}; 97 98static const struct skel_board skel_boards[] = { 99 { 100 .name = "skel-100", 101 .ai_chans = 16, 102 .ai_bits = 12, 103 .have_dio = 1, 104 }, 105 { 106 .name = "skel-200", 107 .ai_chans = 8, 108 .ai_bits = 16, 109 .have_dio = 0, 110 }, 111}; 112 113/* This is used by modprobe to translate PCI IDs to drivers. Should 114 * only be used for PCI and ISA-PnP devices */ 115/* Please add your PCI vendor ID to comedidev.h, and it will be forwarded 116 * upstream. */ 117#define PCI_VENDOR_ID_SKEL 0xdafe 118static DEFINE_PCI_DEVICE_TABLE(skel_pci_table) = { 119 { 120 PCI_VENDOR_ID_SKEL, 0x0100, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, { 121 PCI_VENDOR_ID_SKEL, 0x0200, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, { 122 0} 123}; 124 125MODULE_DEVICE_TABLE(pci, skel_pci_table); 126 127/* 128 * Useful for shorthand access to the particular board structure 129 */ 130#define thisboard ((const struct skel_board *)dev->board_ptr) 131 132/* this structure is for data unique to this hardware driver. If 133 several hardware drivers keep similar information in this structure, 134 feel free to suggest moving the variable to the struct comedi_device struct. */ 135struct skel_private { 136 137 int data; 138 139 /* would be useful for a PCI device */ 140 struct pci_dev *pci_dev; 141 142 /* Used for AO readback */ 143 unsigned int ao_readback[2]; 144}; 145 146/* 147 * most drivers define the following macro to make it easy to 148 * access the private structure. 149 */ 150#define devpriv ((struct skel_private *)dev->private) 151 152/* 153 * The struct comedi_driver structure tells the Comedi core module 154 * which functions to call to configure/deconfigure (attach/detach) 155 * the board, and also about the kernel module that contains 156 * the device code. 157 */ 158static int skel_attach(struct comedi_device *dev, struct comedi_devconfig *it); 159static int skel_detach(struct comedi_device *dev); 160static struct comedi_driver driver_skel = { 161 .driver_name = "dummy", 162 .module = THIS_MODULE, 163 .attach = skel_attach, 164 .detach = skel_detach, 165/* It is not necessary to implement the following members if you are 166 * writing a driver for a ISA PnP or PCI card */ 167 /* Most drivers will support multiple types of boards by 168 * having an array of board structures. These were defined 169 * in skel_boards[] above. Note that the element 'name' 170 * was first in the structure -- Comedi uses this fact to 171 * extract the name of the board without knowing any details 172 * about the structure except for its length. 173 * When a device is attached (by comedi_config), the name 174 * of the device is given to Comedi, and Comedi tries to 175 * match it by going through the list of board names. If 176 * there is a match, the address of the pointer is put 177 * into dev->board_ptr and driver->attach() is called. 178 * 179 * Note that these are not necessary if you can determine 180 * the type of board in software. ISA PnP, PCI, and PCMCIA 181 * devices are such boards. 182 */ 183 .board_name = &skel_boards[0].name, 184 .offset = sizeof(struct skel_board), 185 .num_names = ARRAY_SIZE(skel_boards), 186}; 187 188static int skel_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, 189 struct comedi_insn *insn, unsigned int *data); 190static int skel_ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s, 191 struct comedi_insn *insn, unsigned int *data); 192static int skel_ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, 193 struct comedi_insn *insn, unsigned int *data); 194static int skel_dio_insn_bits(struct comedi_device *dev, 195 struct comedi_subdevice *s, 196 struct comedi_insn *insn, unsigned int *data); 197static int skel_dio_insn_config(struct comedi_device *dev, 198 struct comedi_subdevice *s, 199 struct comedi_insn *insn, unsigned int *data); 200static int skel_ai_cmdtest(struct comedi_device *dev, 201 struct comedi_subdevice *s, struct comedi_cmd *cmd); 202static int skel_ns_to_timer(unsigned int *ns, int round); 203 204/* 205 * Attach is called by the Comedi core to configure the driver 206 * for a particular board. If you specified a board_name array 207 * in the driver structure, dev->board_ptr contains that 208 * address. 209 */ 210static int skel_attach(struct comedi_device *dev, struct comedi_devconfig *it) 211{ 212 struct comedi_subdevice *s; 213 214 printk("comedi%d: skel: ", dev->minor); 215 216/* 217 * If you can probe the device to determine what device in a series 218 * it is, this is the place to do it. Otherwise, dev->board_ptr 219 * should already be initialized. 220 */ 221 /* dev->board_ptr = skel_probe(dev, it); */ 222 223/* 224 * Initialize dev->board_name. Note that we can use the "thisboard" 225 * macro now, since we just initialized it in the last line. 226 */ 227 dev->board_name = thisboard->name; 228 229/* 230 * Allocate the private structure area. alloc_private() is a 231 * convenient macro defined in comedidev.h. 232 */ 233 if (alloc_private(dev, sizeof(struct skel_private)) < 0) 234 return -ENOMEM; 235 236/* 237 * Allocate the subdevice structures. alloc_subdevice() is a 238 * convenient macro defined in comedidev.h. 239 */ 240 if (alloc_subdevices(dev, 3) < 0) 241 return -ENOMEM; 242 243 s = dev->subdevices + 0; 244 /* dev->read_subdev=s; */ 245 /* analog input subdevice */ 246 s->type = COMEDI_SUBD_AI; 247 /* we support single-ended (ground) and differential */ 248 s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_DIFF; 249 s->n_chan = thisboard->ai_chans; 250 s->maxdata = (1 << thisboard->ai_bits) - 1; 251 s->range_table = &range_bipolar10; 252 s->len_chanlist = 16; /* This is the maximum chanlist length that 253 the board can handle */ 254 s->insn_read = skel_ai_rinsn; 255/* 256* s->subdev_flags |= SDF_CMD_READ; 257* s->do_cmd = skel_ai_cmd; 258*/ 259 s->do_cmdtest = skel_ai_cmdtest; 260 261 s = dev->subdevices + 1; 262 /* analog output subdevice */ 263 s->type = COMEDI_SUBD_AO; 264 s->subdev_flags = SDF_WRITABLE; 265 s->n_chan = 1; 266 s->maxdata = 0xffff; 267 s->range_table = &range_bipolar5; 268 s->insn_write = skel_ao_winsn; 269 s->insn_read = skel_ao_rinsn; 270 271 s = dev->subdevices + 2; 272 /* digital i/o subdevice */ 273 if (thisboard->have_dio) { 274 s->type = COMEDI_SUBD_DIO; 275 s->subdev_flags = SDF_READABLE | SDF_WRITABLE; 276 s->n_chan = 16; 277 s->maxdata = 1; 278 s->range_table = &range_digital; 279 s->insn_bits = skel_dio_insn_bits; 280 s->insn_config = skel_dio_insn_config; 281 } else { 282 s->type = COMEDI_SUBD_UNUSED; 283 } 284 285 printk("attached\n"); 286 287 return 0; 288} 289 290/* 291 * _detach is called to deconfigure a device. It should deallocate 292 * resources. 293 * This function is also called when _attach() fails, so it should be 294 * careful not to release resources that were not necessarily 295 * allocated by _attach(). dev->private and dev->subdevices are 296 * deallocated automatically by the core. 297 */ 298static int skel_detach(struct comedi_device *dev) 299{ 300 printk("comedi%d: skel: remove\n", dev->minor); 301 302 return 0; 303} 304 305/* 306 * "instructions" read/write data in "one-shot" or "software-triggered" 307 * mode. 308 */ 309static int skel_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, 310 struct comedi_insn *insn, unsigned int *data) 311{ 312 int n, i; 313 unsigned int d; 314 unsigned int status; 315 316 /* a typical programming sequence */ 317 318 /* write channel to multiplexer */ 319 /* outw(chan,dev->iobase + SKEL_MUX); */ 320 321 /* don't wait for mux to settle */ 322 323 /* convert n samples */ 324 for (n = 0; n < insn->n; n++) { 325 /* trigger conversion */ 326 /* outw(0,dev->iobase + SKEL_CONVERT); */ 327 328#define TIMEOUT 100 329 /* wait for conversion to end */ 330 for (i = 0; i < TIMEOUT; i++) { 331 status = 1; 332 /* status = inb(dev->iobase + SKEL_STATUS); */ 333 if (status) 334 break; 335 } 336 if (i == TIMEOUT) { 337 /* printk() should be used instead of printk() 338 * whenever the code can be called from real-time. */ 339 printk("timeout\n"); 340 return -ETIMEDOUT; 341 } 342 343 /* read data */ 344 /* d = inw(dev->iobase + SKEL_AI_DATA); */ 345 d = 0; 346 347 /* mangle the data as necessary */ 348 d ^= 1 << (thisboard->ai_bits - 1); 349 350 data[n] = d; 351 } 352 353 /* return the number of samples read/written */ 354 return n; 355} 356 357static int skel_ai_cmdtest(struct comedi_device *dev, 358 struct comedi_subdevice *s, struct comedi_cmd *cmd) 359{ 360 int err = 0; 361 int tmp; 362 363 /* cmdtest tests a particular command to see if it is valid. 364 * Using the cmdtest ioctl, a user can create a valid cmd 365 * and then have it executes by the cmd ioctl. 366 * 367 * cmdtest returns 1,2,3,4 or 0, depending on which tests 368 * the command passes. */ 369 370 /* step 1: make sure trigger sources are trivially valid */ 371 372 tmp = cmd->start_src; 373 cmd->start_src &= TRIG_NOW; 374 if (!cmd->start_src || tmp != cmd->start_src) 375 err++; 376 377 tmp = cmd->scan_begin_src; 378 cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT; 379 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src) 380 err++; 381 382 tmp = cmd->convert_src; 383 cmd->convert_src &= TRIG_TIMER | TRIG_EXT; 384 if (!cmd->convert_src || tmp != cmd->convert_src) 385 err++; 386 387 tmp = cmd->scan_end_src; 388 cmd->scan_end_src &= TRIG_COUNT; 389 if (!cmd->scan_end_src || tmp != cmd->scan_end_src) 390 err++; 391 392 tmp = cmd->stop_src; 393 cmd->stop_src &= TRIG_COUNT | TRIG_NONE; 394 if (!cmd->stop_src || tmp != cmd->stop_src) 395 err++; 396 397 if (err) 398 return 1; 399 400 /* step 2: make sure trigger sources are unique and mutually compatible */ 401 402 /* note that mutual compatibility is not an issue here */ 403 if (cmd->scan_begin_src != TRIG_TIMER && 404 cmd->scan_begin_src != TRIG_EXT) 405 err++; 406 if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT) 407 err++; 408 if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE) 409 err++; 410 411 if (err) 412 return 2; 413 414 /* step 3: make sure arguments are trivially compatible */ 415 416 if (cmd->start_arg != 0) { 417 cmd->start_arg = 0; 418 err++; 419 } 420#define MAX_SPEED 10000 /* in nanoseconds */ 421#define MIN_SPEED 1000000000 /* in nanoseconds */ 422 423 if (cmd->scan_begin_src == TRIG_TIMER) { 424 if (cmd->scan_begin_arg < MAX_SPEED) { 425 cmd->scan_begin_arg = MAX_SPEED; 426 err++; 427 } 428 if (cmd->scan_begin_arg > MIN_SPEED) { 429 cmd->scan_begin_arg = MIN_SPEED; 430 err++; 431 } 432 } else { 433 /* external trigger */ 434 /* should be level/edge, hi/lo specification here */ 435 /* should specify multiple external triggers */ 436 if (cmd->scan_begin_arg > 9) { 437 cmd->scan_begin_arg = 9; 438 err++; 439 } 440 } 441 if (cmd->convert_src == TRIG_TIMER) { 442 if (cmd->convert_arg < MAX_SPEED) { 443 cmd->convert_arg = MAX_SPEED; 444 err++; 445 } 446 if (cmd->convert_arg > MIN_SPEED) { 447 cmd->convert_arg = MIN_SPEED; 448 err++; 449 } 450 } else { 451 /* external trigger */ 452 /* see above */ 453 if (cmd->convert_arg > 9) { 454 cmd->convert_arg = 9; 455 err++; 456 } 457 } 458 459 if (cmd->scan_end_arg != cmd->chanlist_len) { 460 cmd->scan_end_arg = cmd->chanlist_len; 461 err++; 462 } 463 if (cmd->stop_src == TRIG_COUNT) { 464 if (cmd->stop_arg > 0x00ffffff) { 465 cmd->stop_arg = 0x00ffffff; 466 err++; 467 } 468 } else { 469 /* TRIG_NONE */ 470 if (cmd->stop_arg != 0) { 471 cmd->stop_arg = 0; 472 err++; 473 } 474 } 475 476 if (err) 477 return 3; 478 479 /* step 4: fix up any arguments */ 480 481 if (cmd->scan_begin_src == TRIG_TIMER) { 482 tmp = cmd->scan_begin_arg; 483 skel_ns_to_timer(&cmd->scan_begin_arg, 484 cmd->flags & TRIG_ROUND_MASK); 485 if (tmp != cmd->scan_begin_arg) 486 err++; 487 } 488 if (cmd->convert_src == TRIG_TIMER) { 489 tmp = cmd->convert_arg; 490 skel_ns_to_timer(&cmd->convert_arg, 491 cmd->flags & TRIG_ROUND_MASK); 492 if (tmp != cmd->convert_arg) 493 err++; 494 if (cmd->scan_begin_src == TRIG_TIMER && 495 cmd->scan_begin_arg < 496 cmd->convert_arg * cmd->scan_end_arg) { 497 cmd->scan_begin_arg = 498 cmd->convert_arg * cmd->scan_end_arg; 499 err++; 500 } 501 } 502 503 if (err) 504 return 4; 505 506 return 0; 507} 508 509/* This function doesn't require a particular form, this is just 510 * what happens to be used in some of the drivers. It should 511 * convert ns nanoseconds to a counter value suitable for programming 512 * the device. Also, it should adjust ns so that it cooresponds to 513 * the actual time that the device will use. */ 514static int skel_ns_to_timer(unsigned int *ns, int round) 515{ 516 /* trivial timer */ 517 /* if your timing is done through two cascaded timers, the 518 * i8253_cascade_ns_to_timer() function in 8253.h can be 519 * very helpful. There are also i8254_load() and i8254_mm_load() 520 * which can be used to load values into the ubiquitous 8254 counters 521 */ 522 523 return *ns; 524} 525 526static int skel_ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s, 527 struct comedi_insn *insn, unsigned int *data) 528{ 529 int i; 530 int chan = CR_CHAN(insn->chanspec); 531 532 printk("skel_ao_winsn\n"); 533 /* Writing a list of values to an AO channel is probably not 534 * very useful, but that's how the interface is defined. */ 535 for (i = 0; i < insn->n; i++) { 536 /* a typical programming sequence */ 537 /* outw(data[i],dev->iobase + SKEL_DA0 + chan); */ 538 devpriv->ao_readback[chan] = data[i]; 539 } 540 541 /* return the number of samples read/written */ 542 return i; 543} 544 545/* AO subdevices should have a read insn as well as a write insn. 546 * Usually this means copying a value stored in devpriv. */ 547static int skel_ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, 548 struct comedi_insn *insn, unsigned int *data) 549{ 550 int i; 551 int chan = CR_CHAN(insn->chanspec); 552 553 for (i = 0; i < insn->n; i++) 554 data[i] = devpriv->ao_readback[chan]; 555 556 return i; 557} 558 559/* DIO devices are slightly special. Although it is possible to 560 * implement the insn_read/insn_write interface, it is much more 561 * useful to applications if you implement the insn_bits interface. 562 * This allows packed reading/writing of the DIO channels. The 563 * comedi core can convert between insn_bits and insn_read/write */ 564static int skel_dio_insn_bits(struct comedi_device *dev, 565 struct comedi_subdevice *s, 566 struct comedi_insn *insn, unsigned int *data) 567{ 568 if (insn->n != 2) 569 return -EINVAL; 570 571 /* The insn data is a mask in data[0] and the new data 572 * in data[1], each channel cooresponding to a bit. */ 573 if (data[0]) { 574 s->state &= ~data[0]; 575 s->state |= data[0] & data[1]; 576 /* Write out the new digital output lines */ 577 /* outw(s->state,dev->iobase + SKEL_DIO); */ 578 } 579 580 /* on return, data[1] contains the value of the digital 581 * input and output lines. */ 582 /* data[1]=inw(dev->iobase + SKEL_DIO); */ 583 /* or we could just return the software copy of the output values if 584 * it was a purely digital output subdevice */ 585 /* data[1]=s->state; */ 586 587 return 2; 588} 589 590static int skel_dio_insn_config(struct comedi_device *dev, 591 struct comedi_subdevice *s, 592 struct comedi_insn *insn, unsigned int *data) 593{ 594 int chan = CR_CHAN(insn->chanspec); 595 596 /* The input or output configuration of each digital line is 597 * configured by a special insn_config instruction. chanspec 598 * contains the channel to be changed, and data[0] contains the 599 * value COMEDI_INPUT or COMEDI_OUTPUT. */ 600 switch (data[0]) { 601 case INSN_CONFIG_DIO_OUTPUT: 602 s->io_bits |= 1 << chan; 603 break; 604 case INSN_CONFIG_DIO_INPUT: 605 s->io_bits &= ~(1 << chan); 606 break; 607 case INSN_CONFIG_DIO_QUERY: 608 data[1] = 609 (s->io_bits & (1 << chan)) ? COMEDI_OUTPUT : COMEDI_INPUT; 610 return insn->n; 611 break; 612 default: 613 return -EINVAL; 614 break; 615 } 616 /* outw(s->io_bits,dev->iobase + SKEL_DIO_CONFIG); */ 617 618 return insn->n; 619} 620 621/* 622 * A convenient macro that defines init_module() and cleanup_module(), 623 * as necessary. 624 */ 625COMEDI_INITCLEANUP(driver_skel); 626/* If you are writing a PCI driver you should use COMEDI_PCI_INITCLEANUP instead. 627*/ 628/* COMEDI_PCI_INITCLEANUP(driver_skel, skel_pci_table) */ 629