8255.c revision e4e1f289be88a75dc8b63d50ade1f9a2e6168021
1/* 2 comedi/drivers/8255.c 3 Driver for 8255 4 5 COMEDI - Linux Control and Measurement Device Interface 6 Copyright (C) 1998 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: 8255 25Description: generic 8255 support 26Devices: [standard] 8255 (8255) 27Author: ds 28Status: works 29Updated: Fri, 7 Jun 2002 12:56:45 -0700 30 31The classic in digital I/O. The 8255 appears in Comedi as a single 32digital I/O subdevice with 24 channels. The channel 0 corresponds 33to the 8255's port A, bit 0; channel 23 corresponds to port C, bit 347. Direction configuration is done in blocks, with channels 0-7, 358-15, 16-19, and 20-23 making up the 4 blocks. The only 8255 mode 36supported is mode 0. 37 38You should enable compilation this driver if you plan to use a board 39that has an 8255 chip. For multifunction boards, the main driver will 40configure the 8255 subdevice automatically. 41 42This driver also works independently with ISA and PCI cards that 43directly map the 8255 registers to I/O ports, including cards with 44multiple 8255 chips. To configure the driver for such a card, the 45option list should be a list of the I/O port bases for each of the 468255 chips. For example, 47 48 comedi_config /dev/comedi0 8255 0x200,0x204,0x208,0x20c 49 50Note that most PCI 8255 boards do NOT work with this driver, and 51need a separate driver as a wrapper. For those that do work, the 52I/O port base address can be found in the output of 'lspci -v'. 53 54*/ 55 56/* 57 This file contains an exported subdevice for driving an 8255. 58 59 To use this subdevice as part of another driver, you need to 60 set up the subdevice in the attach function of the driver by 61 calling: 62 63 subdev_8255_init(device, subdevice, callback_function, arg) 64 65 device and subdevice are pointers to the device and subdevice 66 structures. callback_function will be called to provide the 67 low-level input/output to the device, i.e., actual register 68 access. callback_function will be called with the value of arg 69 as the last parameter. If the 8255 device is mapped as 4 70 consecutive I/O ports, you can use NULL for callback_function 71 and the I/O port base for arg, and an internal function will 72 handle the register access. 73 74 In addition, if the main driver handles interrupts, you can 75 enable commands on the subdevice by calling subdev_8255_init_irq() 76 instead. Then, when you get an interrupt that is likely to be 77 from the 8255, you should call subdev_8255_interrupt(), which 78 will copy the latched value to a Comedi buffer. 79 */ 80 81#include "../comedidev.h" 82 83#include <linux/ioport.h> 84#include <linux/slab.h> 85#include "8255.h" 86 87#define _8255_SIZE 4 88 89#define _8255_DATA 0 90#define _8255_CR 3 91 92#define CR_C_LO_IO 0x01 93#define CR_B_IO 0x02 94#define CR_B_MODE 0x04 95#define CR_C_HI_IO 0x08 96#define CR_A_IO 0x10 97#define CR_A_MODE(a) ((a)<<5) 98#define CR_CW 0x80 99 100struct subdev_8255_struct { 101 unsigned long cb_arg; 102 int (*cb_func) (int, int, int, unsigned long); 103 int have_irq; 104}; 105 106#define CALLBACK_ARG (((struct subdev_8255_struct *)s->private)->cb_arg) 107#define CALLBACK_FUNC (((struct subdev_8255_struct *)s->private)->cb_func) 108#define subdevpriv ((struct subdev_8255_struct *)s->private) 109 110static int dev_8255_attach(struct comedi_device *dev, 111 struct comedi_devconfig *it); 112static int dev_8255_detach(struct comedi_device *dev); 113static struct comedi_driver driver_8255 = { 114 .driver_name = "8255", 115 .module = THIS_MODULE, 116 .attach = dev_8255_attach, 117 .detach = dev_8255_detach, 118}; 119 120static int __init driver_8255_init_module(void) 121{ 122 return comedi_driver_register(&driver_8255); 123} 124 125static void __exit driver_8255_cleanup_module(void) 126{ 127 comedi_driver_unregister(&driver_8255); 128} 129 130module_init(driver_8255_init_module); 131module_exit(driver_8255_cleanup_module); 132 133static void do_config(struct comedi_device *dev, struct comedi_subdevice *s); 134 135void subdev_8255_interrupt(struct comedi_device *dev, 136 struct comedi_subdevice *s) 137{ 138 short d; 139 140 d = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG); 141 d |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8); 142 143 comedi_buf_put(s->async, d); 144 s->async->events |= COMEDI_CB_EOS; 145 146 comedi_event(dev, s); 147} 148EXPORT_SYMBOL(subdev_8255_interrupt); 149 150static int subdev_8255_cb(int dir, int port, int data, unsigned long arg) 151{ 152 unsigned long iobase = arg; 153 154 if (dir) { 155 outb(data, iobase + port); 156 return 0; 157 } else { 158 return inb(iobase + port); 159 } 160} 161 162static int subdev_8255_insn(struct comedi_device *dev, 163 struct comedi_subdevice *s, 164 struct comedi_insn *insn, unsigned int *data) 165{ 166 if (data[0]) { 167 s->state &= ~data[0]; 168 s->state |= (data[0] & data[1]); 169 170 if (data[0] & 0xff) 171 CALLBACK_FUNC(1, _8255_DATA, s->state & 0xff, 172 CALLBACK_ARG); 173 if (data[0] & 0xff00) 174 CALLBACK_FUNC(1, _8255_DATA + 1, (s->state >> 8) & 0xff, 175 CALLBACK_ARG); 176 if (data[0] & 0xff0000) 177 CALLBACK_FUNC(1, _8255_DATA + 2, 178 (s->state >> 16) & 0xff, CALLBACK_ARG); 179 } 180 181 data[1] = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG); 182 data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8); 183 data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 2, 0, CALLBACK_ARG) << 16); 184 185 return 2; 186} 187 188static int subdev_8255_insn_config(struct comedi_device *dev, 189 struct comedi_subdevice *s, 190 struct comedi_insn *insn, unsigned int *data) 191{ 192 unsigned int mask; 193 unsigned int bits; 194 195 mask = 1 << CR_CHAN(insn->chanspec); 196 if (mask & 0x0000ff) 197 bits = 0x0000ff; 198 else if (mask & 0x00ff00) 199 bits = 0x00ff00; 200 else if (mask & 0x0f0000) 201 bits = 0x0f0000; 202 else 203 bits = 0xf00000; 204 205 switch (data[0]) { 206 case INSN_CONFIG_DIO_INPUT: 207 s->io_bits &= ~bits; 208 break; 209 case INSN_CONFIG_DIO_OUTPUT: 210 s->io_bits |= bits; 211 break; 212 case INSN_CONFIG_DIO_QUERY: 213 data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT; 214 return insn->n; 215 break; 216 default: 217 return -EINVAL; 218 } 219 220 do_config(dev, s); 221 222 return 1; 223} 224 225static void do_config(struct comedi_device *dev, struct comedi_subdevice *s) 226{ 227 int config; 228 229 config = CR_CW; 230 /* 1 in io_bits indicates output, 1 in config indicates input */ 231 if (!(s->io_bits & 0x0000ff)) 232 config |= CR_A_IO; 233 if (!(s->io_bits & 0x00ff00)) 234 config |= CR_B_IO; 235 if (!(s->io_bits & 0x0f0000)) 236 config |= CR_C_LO_IO; 237 if (!(s->io_bits & 0xf00000)) 238 config |= CR_C_HI_IO; 239 CALLBACK_FUNC(1, _8255_CR, config, CALLBACK_ARG); 240} 241 242static int subdev_8255_cmdtest(struct comedi_device *dev, 243 struct comedi_subdevice *s, 244 struct comedi_cmd *cmd) 245{ 246 int err = 0; 247 unsigned int tmp; 248 249 /* step 1 */ 250 251 tmp = cmd->start_src; 252 cmd->start_src &= TRIG_NOW; 253 if (!cmd->start_src || tmp != cmd->start_src) 254 err++; 255 256 tmp = cmd->scan_begin_src; 257 cmd->scan_begin_src &= TRIG_EXT; 258 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src) 259 err++; 260 261 tmp = cmd->convert_src; 262 cmd->convert_src &= TRIG_FOLLOW; 263 if (!cmd->convert_src || tmp != cmd->convert_src) 264 err++; 265 266 tmp = cmd->scan_end_src; 267 cmd->scan_end_src &= TRIG_COUNT; 268 if (!cmd->scan_end_src || tmp != cmd->scan_end_src) 269 err++; 270 271 tmp = cmd->stop_src; 272 cmd->stop_src &= TRIG_NONE; 273 if (!cmd->stop_src || tmp != cmd->stop_src) 274 err++; 275 276 if (err) 277 return 1; 278 279 /* step 2 */ 280 281 if (err) 282 return 2; 283 284 /* step 3 */ 285 286 if (cmd->start_arg != 0) { 287 cmd->start_arg = 0; 288 err++; 289 } 290 if (cmd->scan_begin_arg != 0) { 291 cmd->scan_begin_arg = 0; 292 err++; 293 } 294 if (cmd->convert_arg != 0) { 295 cmd->convert_arg = 0; 296 err++; 297 } 298 if (cmd->scan_end_arg != 1) { 299 cmd->scan_end_arg = 1; 300 err++; 301 } 302 if (cmd->stop_arg != 0) { 303 cmd->stop_arg = 0; 304 err++; 305 } 306 307 if (err) 308 return 3; 309 310 /* step 4 */ 311 312 if (err) 313 return 4; 314 315 return 0; 316} 317 318static int subdev_8255_cmd(struct comedi_device *dev, 319 struct comedi_subdevice *s) 320{ 321 /* FIXME */ 322 323 return 0; 324} 325 326static int subdev_8255_cancel(struct comedi_device *dev, 327 struct comedi_subdevice *s) 328{ 329 /* FIXME */ 330 331 return 0; 332} 333 334int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s, 335 int (*cb) (int, int, int, unsigned long), 336 unsigned long arg) 337{ 338 s->type = COMEDI_SUBD_DIO; 339 s->subdev_flags = SDF_READABLE | SDF_WRITABLE; 340 s->n_chan = 24; 341 s->range_table = &range_digital; 342 s->maxdata = 1; 343 344 s->private = kmalloc(sizeof(struct subdev_8255_struct), GFP_KERNEL); 345 if (!s->private) 346 return -ENOMEM; 347 348 CALLBACK_ARG = arg; 349 if (cb == NULL) 350 CALLBACK_FUNC = subdev_8255_cb; 351 else 352 CALLBACK_FUNC = cb; 353 s->insn_bits = subdev_8255_insn; 354 s->insn_config = subdev_8255_insn_config; 355 356 s->state = 0; 357 s->io_bits = 0; 358 do_config(dev, s); 359 360 return 0; 361} 362EXPORT_SYMBOL(subdev_8255_init); 363 364int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s, 365 int (*cb) (int, int, int, unsigned long), 366 unsigned long arg) 367{ 368 int ret; 369 370 ret = subdev_8255_init(dev, s, cb, arg); 371 if (ret < 0) 372 return ret; 373 374 s->do_cmdtest = subdev_8255_cmdtest; 375 s->do_cmd = subdev_8255_cmd; 376 s->cancel = subdev_8255_cancel; 377 378 subdevpriv->have_irq = 1; 379 380 return 0; 381} 382EXPORT_SYMBOL(subdev_8255_init_irq); 383 384void subdev_8255_cleanup(struct comedi_device *dev, struct comedi_subdevice *s) 385{ 386 kfree(s->private); 387} 388EXPORT_SYMBOL(subdev_8255_cleanup); 389 390/* 391 392 Start of the 8255 standalone device 393 394 */ 395 396static int dev_8255_attach(struct comedi_device *dev, 397 struct comedi_devconfig *it) 398{ 399 int ret; 400 unsigned long iobase; 401 int i; 402 403 dev->board_name = "8255"; 404 405 for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) { 406 iobase = it->options[i]; 407 if (!iobase) 408 break; 409 } 410 if (i == 0) { 411 printk(KERN_WARNING 412 "comedi%d: 8255: no devices specified\n", dev->minor); 413 return -EINVAL; 414 } 415 416 ret = alloc_subdevices(dev, i); 417 if (ret < 0) { 418 /* FIXME this printk call should give a proper message, the 419 * below line just maintains previous functionality */ 420 printk("comedi%d: 8255:", dev->minor); 421 return ret; 422 } 423 424 printk(KERN_INFO "comedi%d: 8255:", dev->minor); 425 426 for (i = 0; i < dev->n_subdevices; i++) { 427 iobase = it->options[i]; 428 429 printk(" 0x%04lx", iobase); 430 if (!request_region(iobase, _8255_SIZE, "8255")) { 431 printk(" (I/O port conflict)"); 432 433 dev->subdevices[i].type = COMEDI_SUBD_UNUSED; 434 } else { 435 subdev_8255_init(dev, dev->subdevices + i, NULL, 436 iobase); 437 } 438 } 439 440 printk("\n"); 441 442 return 0; 443} 444 445static int dev_8255_detach(struct comedi_device *dev) 446{ 447 int i; 448 unsigned long iobase; 449 struct comedi_subdevice *s; 450 451 printk(KERN_INFO "comedi%d: 8255: remove\n", dev->minor); 452 453 for (i = 0; i < dev->n_subdevices; i++) { 454 s = dev->subdevices + i; 455 if (s->type != COMEDI_SUBD_UNUSED) { 456 iobase = CALLBACK_ARG; 457 release_region(iobase, _8255_SIZE); 458 } 459 subdev_8255_cleanup(dev, s); 460 } 461 462 return 0; 463} 464 465MODULE_AUTHOR("Comedi http://www.comedi.org"); 466MODULE_DESCRIPTION("Comedi low-level driver"); 467MODULE_LICENSE("GPL"); 468