1 /* 2 * Parallel-port resource manager code. 3 * 4 * Authors: David Campbell <campbell@tirian.che.curtin.edu.au> 5 * Tim Waugh <tim@cyberelk.demon.co.uk> 6 * Jose Renau <renau@acm.org> 7 * Philip Blundell <philb@gnu.org> 8 * Andrea Arcangeli 9 * 10 * based on work by Grant Guenther <grant@torque.net> 11 * and Philip Blundell 12 * 13 * Any part of this program may be used in documents licensed under 14 * the GNU Free Documentation License, Version 1.1 or any later version 15 * published by the Free Software Foundation. 16 */ 17 18 #undef PARPORT_DEBUG_SHARING /* undef for production */ 19 20 #include <linux/module.h> 21 #include <linux/string.h> 22 #include <linux/threads.h> 23 #include <linux/parport.h> 24 #include <linux/delay.h> 25 #include <linux/errno.h> 26 #include <linux/interrupt.h> 27 #include <linux/ioport.h> 28 #include <linux/kernel.h> 29 #include <linux/slab.h> 30 #include <linux/sched/signal.h> 31 #include <linux/kmod.h> 32 #include <linux/device.h> 33 34 #include <linux/spinlock.h> 35 #include <linux/mutex.h> 36 #include <asm/irq.h> 37 38 #undef PARPORT_PARANOID 39 40 #define PARPORT_DEFAULT_TIMESLICE (HZ/5) 41 42 unsigned long parport_default_timeslice = PARPORT_DEFAULT_TIMESLICE; 43 int parport_default_spintime = DEFAULT_SPIN_TIME; 44 45 static LIST_HEAD(portlist); 46 static DEFINE_SPINLOCK(parportlist_lock); 47 48 /* list of all allocated ports, sorted by ->number */ 49 static LIST_HEAD(all_ports); 50 static DEFINE_SPINLOCK(full_list_lock); 51 52 static LIST_HEAD(drivers); 53 54 static DEFINE_MUTEX(registration_lock); 55 56 /* What you can do to a port that's gone away.. */ 57 static void dead_write_lines(struct parport *p, unsigned char b){} 58 static unsigned char dead_read_lines(struct parport *p) { return 0; } 59 static unsigned char dead_frob_lines(struct parport *p, unsigned char b, 60 unsigned char c) { return 0; } 61 static void dead_onearg(struct parport *p){} 62 static void dead_initstate(struct pardevice *d, struct parport_state *s) { } 63 static void dead_state(struct parport *p, struct parport_state *s) { } 64 static size_t dead_write(struct parport *p, const void *b, size_t l, int f) 65 { return 0; } 66 static size_t dead_read(struct parport *p, void *b, size_t l, int f) 67 { return 0; } 68 static struct parport_operations dead_ops = { 69 .write_data = dead_write_lines, /* data */ 70 .read_data = dead_read_lines, 71 72 .write_control = dead_write_lines, /* control */ 73 .read_control = dead_read_lines, 74 .frob_control = dead_frob_lines, 75 76 .read_status = dead_read_lines, /* status */ 77 78 .enable_irq = dead_onearg, /* enable_irq */ 79 .disable_irq = dead_onearg, /* disable_irq */ 80 81 .data_forward = dead_onearg, /* data_forward */ 82 .data_reverse = dead_onearg, /* data_reverse */ 83 84 .init_state = dead_initstate, /* init_state */ 85 .save_state = dead_state, 86 .restore_state = dead_state, 87 88 .epp_write_data = dead_write, /* epp */ 89 .epp_read_data = dead_read, 90 .epp_write_addr = dead_write, 91 .epp_read_addr = dead_read, 92 93 .ecp_write_data = dead_write, /* ecp */ 94 .ecp_read_data = dead_read, 95 .ecp_write_addr = dead_write, 96 97 .compat_write_data = dead_write, /* compat */ 98 .nibble_read_data = dead_read, /* nibble */ 99 .byte_read_data = dead_read, /* byte */ 100 101 .owner = NULL, 102 }; 103 104 static struct device_type parport_device_type = { 105 .name = "parport", 106 }; 107 108 static int is_parport(struct device *dev) 109 { 110 return dev->type == &parport_device_type; 111 } 112 113 static int parport_probe(struct device *dev) 114 { 115 struct parport_driver *drv; 116 117 if (is_parport(dev)) 118 return -ENODEV; 119 120 drv = to_parport_driver(dev->driver); 121 if (!drv->probe) { 122 /* if driver has not defined a custom probe */ 123 struct pardevice *par_dev = to_pardevice(dev); 124 125 if (strcmp(par_dev->name, drv->name)) 126 return -ENODEV; 127 return 0; 128 } 129 /* if driver defined its own probe */ 130 return drv->probe(to_pardevice(dev)); 131 } 132 133 static struct bus_type parport_bus_type = { 134 .name = "parport", 135 .probe = parport_probe, 136 }; 137 138 int parport_bus_init(void) 139 { 140 return bus_register(&parport_bus_type); 141 } 142 143 void parport_bus_exit(void) 144 { 145 bus_unregister(&parport_bus_type); 146 } 147 148 /* 149 * iterates through all the drivers registered with the bus and sends the port 150 * details to the match_port callback of the driver, so that the driver can 151 * know about the new port that just registered with the bus and decide if it 152 * wants to use this new port. 153 */ 154 static int driver_check(struct device_driver *dev_drv, void *_port) 155 { 156 struct parport *port = _port; 157 struct parport_driver *drv = to_parport_driver(dev_drv); 158 159 if (drv->match_port) 160 drv->match_port(port); 161 return 0; 162 } 163 164 /* Call attach(port) for each registered driver. */ 165 static void attach_driver_chain(struct parport *port) 166 { 167 /* caller has exclusive registration_lock */ 168 struct parport_driver *drv; 169 170 list_for_each_entry(drv, &drivers, list) 171 drv->attach(port); 172 173 /* 174 * call the driver_check function of the drivers registered in 175 * new device model 176 */ 177 178 bus_for_each_drv(&parport_bus_type, NULL, port, driver_check); 179 } 180 181 static int driver_detach(struct device_driver *_drv, void *_port) 182 { 183 struct parport *port = _port; 184 struct parport_driver *drv = to_parport_driver(_drv); 185 186 if (drv->detach) 187 drv->detach(port); 188 return 0; 189 } 190 191 /* Call detach(port) for each registered driver. */ 192 static void detach_driver_chain(struct parport *port) 193 { 194 struct parport_driver *drv; 195 /* caller has exclusive registration_lock */ 196 list_for_each_entry(drv, &drivers, list) 197 drv->detach(port); 198 199 /* 200 * call the detach function of the drivers registered in 201 * new device model 202 */ 203 204 bus_for_each_drv(&parport_bus_type, NULL, port, driver_detach); 205 } 206 207 /* Ask kmod for some lowlevel drivers. */ 208 static void get_lowlevel_driver(void) 209 { 210 /* 211 * There is no actual module called this: you should set 212 * up an alias for modutils. 213 */ 214 request_module("parport_lowlevel"); 215 } 216 217 /* 218 * iterates through all the devices connected to the bus and sends the device 219 * details to the match_port callback of the driver, so that the driver can 220 * know what are all the ports that are connected to the bus and choose the 221 * port to which it wants to register its device. 222 */ 223 static int port_check(struct device *dev, void *dev_drv) 224 { 225 struct parport_driver *drv = dev_drv; 226 227 /* only send ports, do not send other devices connected to bus */ 228 if (is_parport(dev)) 229 drv->match_port(to_parport_dev(dev)); 230 return 0; 231 } 232 233 /** 234 * parport_register_driver - register a parallel port device driver 235 * @drv: structure describing the driver 236 * @owner: owner module of drv 237 * @mod_name: module name string 238 * 239 * This can be called by a parallel port device driver in order 240 * to receive notifications about ports being found in the 241 * system, as well as ports no longer available. 242 * 243 * If devmodel is true then the new device model is used 244 * for registration. 245 * 246 * The @drv structure is allocated by the caller and must not be 247 * deallocated until after calling parport_unregister_driver(). 248 * 249 * If using the non device model: 250 * The driver's attach() function may block. The port that 251 * attach() is given will be valid for the duration of the 252 * callback, but if the driver wants to take a copy of the 253 * pointer it must call parport_get_port() to do so. Calling 254 * parport_register_device() on that port will do this for you. 255 * 256 * The driver's detach() function may block. The port that 257 * detach() is given will be valid for the duration of the 258 * callback, but if the driver wants to take a copy of the 259 * pointer it must call parport_get_port() to do so. 260 * 261 * 262 * Returns 0 on success. The non device model will always succeeds. 263 * but the new device model can fail and will return the error code. 264 **/ 265 266 int __parport_register_driver(struct parport_driver *drv, struct module *owner, 267 const char *mod_name) 268 { 269 if (list_empty(&portlist)) 270 get_lowlevel_driver(); 271 272 if (drv->devmodel) { 273 /* using device model */ 274 int ret; 275 276 /* initialize common driver fields */ 277 drv->driver.name = drv->name; 278 drv->driver.bus = &parport_bus_type; 279 drv->driver.owner = owner; 280 drv->driver.mod_name = mod_name; 281 ret = driver_register(&drv->driver); 282 if (ret) 283 return ret; 284 285 mutex_lock(®istration_lock); 286 if (drv->match_port) 287 bus_for_each_dev(&parport_bus_type, NULL, drv, 288 port_check); 289 mutex_unlock(®istration_lock); 290 } else { 291 struct parport *port; 292 293 drv->devmodel = false; 294 295 mutex_lock(®istration_lock); 296 list_for_each_entry(port, &portlist, list) 297 drv->attach(port); 298 list_add(&drv->list, &drivers); 299 mutex_unlock(®istration_lock); 300 } 301 302 return 0; 303 } 304 EXPORT_SYMBOL(__parport_register_driver); 305 306 static int port_detach(struct device *dev, void *_drv) 307 { 308 struct parport_driver *drv = _drv; 309 310 if (is_parport(dev) && drv->detach) 311 drv->detach(to_parport_dev(dev)); 312 313 return 0; 314 } 315 316 /** 317 * parport_unregister_driver - deregister a parallel port device driver 318 * @drv: structure describing the driver that was given to 319 * parport_register_driver() 320 * 321 * This should be called by a parallel port device driver that 322 * has registered itself using parport_register_driver() when it 323 * is about to be unloaded. 324 * 325 * When it returns, the driver's attach() routine will no longer 326 * be called, and for each port that attach() was called for, the 327 * detach() routine will have been called. 328 * 329 * All the driver's attach() and detach() calls are guaranteed to have 330 * finished by the time this function returns. 331 **/ 332 333 void parport_unregister_driver(struct parport_driver *drv) 334 { 335 struct parport *port; 336 337 mutex_lock(®istration_lock); 338 if (drv->devmodel) { 339 bus_for_each_dev(&parport_bus_type, NULL, drv, port_detach); 340 driver_unregister(&drv->driver); 341 } else { 342 list_del_init(&drv->list); 343 list_for_each_entry(port, &portlist, list) 344 drv->detach(port); 345 } 346 mutex_unlock(®istration_lock); 347 } 348 EXPORT_SYMBOL(parport_unregister_driver); 349 350 static void free_port(struct device *dev) 351 { 352 int d; 353 struct parport *port = to_parport_dev(dev); 354 355 spin_lock(&full_list_lock); 356 list_del(&port->full_list); 357 spin_unlock(&full_list_lock); 358 for (d = 0; d < 5; d++) { 359 kfree(port->probe_info[d].class_name); 360 kfree(port->probe_info[d].mfr); 361 kfree(port->probe_info[d].model); 362 kfree(port->probe_info[d].cmdset); 363 kfree(port->probe_info[d].description); 364 } 365 366 kfree(port->name); 367 kfree(port); 368 } 369 370 /** 371 * parport_get_port - increment a port's reference count 372 * @port: the port 373 * 374 * This ensures that a struct parport pointer remains valid 375 * until the matching parport_put_port() call. 376 **/ 377 378 struct parport *parport_get_port(struct parport *port) 379 { 380 struct device *dev = get_device(&port->bus_dev); 381 382 return to_parport_dev(dev); 383 } 384 EXPORT_SYMBOL(parport_get_port); 385 386 void parport_del_port(struct parport *port) 387 { 388 device_unregister(&port->bus_dev); 389 } 390 EXPORT_SYMBOL(parport_del_port); 391 392 /** 393 * parport_put_port - decrement a port's reference count 394 * @port: the port 395 * 396 * This should be called once for each call to parport_get_port(), 397 * once the port is no longer needed. When the reference count reaches 398 * zero (port is no longer used), free_port is called. 399 **/ 400 401 void parport_put_port(struct parport *port) 402 { 403 put_device(&port->bus_dev); 404 } 405 EXPORT_SYMBOL(parport_put_port); 406 407 /** 408 * parport_register_port - register a parallel port 409 * @base: base I/O address 410 * @irq: IRQ line 411 * @dma: DMA channel 412 * @ops: pointer to the port driver's port operations structure 413 * 414 * When a parallel port (lowlevel) driver finds a port that 415 * should be made available to parallel port device drivers, it 416 * should call parport_register_port(). The @base, @irq, and 417 * @dma parameters are for the convenience of port drivers, and 418 * for ports where they aren't meaningful needn't be set to 419 * anything special. They can be altered afterwards by adjusting 420 * the relevant members of the parport structure that is returned 421 * and represents the port. They should not be tampered with 422 * after calling parport_announce_port, however. 423 * 424 * If there are parallel port device drivers in the system that 425 * have registered themselves using parport_register_driver(), 426 * they are not told about the port at this time; that is done by 427 * parport_announce_port(). 428 * 429 * The @ops structure is allocated by the caller, and must not be 430 * deallocated before calling parport_remove_port(). 431 * 432 * If there is no memory to allocate a new parport structure, 433 * this function will return %NULL. 434 **/ 435 436 struct parport *parport_register_port(unsigned long base, int irq, int dma, 437 struct parport_operations *ops) 438 { 439 struct list_head *l; 440 struct parport *tmp; 441 int num; 442 int device; 443 char *name; 444 int ret; 445 446 tmp = kzalloc(sizeof(struct parport), GFP_KERNEL); 447 if (!tmp) 448 return NULL; 449 450 /* Init our structure */ 451 tmp->base = base; 452 tmp->irq = irq; 453 tmp->dma = dma; 454 tmp->muxport = tmp->daisy = tmp->muxsel = -1; 455 tmp->modes = 0; 456 INIT_LIST_HEAD(&tmp->list); 457 tmp->devices = tmp->cad = NULL; 458 tmp->flags = 0; 459 tmp->ops = ops; 460 tmp->physport = tmp; 461 memset(tmp->probe_info, 0, 5 * sizeof(struct parport_device_info)); 462 rwlock_init(&tmp->cad_lock); 463 spin_lock_init(&tmp->waitlist_lock); 464 spin_lock_init(&tmp->pardevice_lock); 465 tmp->ieee1284.mode = IEEE1284_MODE_COMPAT; 466 tmp->ieee1284.phase = IEEE1284_PH_FWD_IDLE; 467 sema_init(&tmp->ieee1284.irq, 0); 468 tmp->spintime = parport_default_spintime; 469 atomic_set(&tmp->ref_count, 1); 470 INIT_LIST_HEAD(&tmp->full_list); 471 472 name = kmalloc(15, GFP_KERNEL); 473 if (!name) { 474 kfree(tmp); 475 return NULL; 476 } 477 /* Search for the lowest free parport number. */ 478 479 spin_lock(&full_list_lock); 480 for (l = all_ports.next, num = 0; l != &all_ports; l = l->next, num++) { 481 struct parport *p = list_entry(l, struct parport, full_list); 482 if (p->number != num) 483 break; 484 } 485 tmp->portnum = tmp->number = num; 486 list_add_tail(&tmp->full_list, l); 487 spin_unlock(&full_list_lock); 488 489 /* 490 * Now that the portnum is known finish doing the Init. 491 */ 492 sprintf(name, "parport%d", tmp->portnum = tmp->number); 493 tmp->name = name; 494 tmp->bus_dev.bus = &parport_bus_type; 495 tmp->bus_dev.release = free_port; 496 dev_set_name(&tmp->bus_dev, name); 497 tmp->bus_dev.type = &parport_device_type; 498 499 for (device = 0; device < 5; device++) 500 /* assume the worst */ 501 tmp->probe_info[device].class = PARPORT_CLASS_LEGACY; 502 503 tmp->waithead = tmp->waittail = NULL; 504 505 ret = device_register(&tmp->bus_dev); 506 if (ret) { 507 put_device(&tmp->bus_dev); 508 return NULL; 509 } 510 511 return tmp; 512 } 513 EXPORT_SYMBOL(parport_register_port); 514 515 /** 516 * parport_announce_port - tell device drivers about a parallel port 517 * @port: parallel port to announce 518 * 519 * After a port driver has registered a parallel port with 520 * parport_register_port, and performed any necessary 521 * initialisation or adjustments, it should call 522 * parport_announce_port() in order to notify all device drivers 523 * that have called parport_register_driver(). Their attach() 524 * functions will be called, with @port as the parameter. 525 **/ 526 527 void parport_announce_port(struct parport *port) 528 { 529 int i; 530 531 #ifdef CONFIG_PARPORT_1284 532 /* Analyse the IEEE1284.3 topology of the port. */ 533 parport_daisy_init(port); 534 #endif 535 536 if (!port->dev) 537 printk(KERN_WARNING "%s: fix this legacy no-device port driver!\n", 538 port->name); 539 540 parport_proc_register(port); 541 mutex_lock(®istration_lock); 542 spin_lock_irq(&parportlist_lock); 543 list_add_tail(&port->list, &portlist); 544 for (i = 1; i < 3; i++) { 545 struct parport *slave = port->slaves[i-1]; 546 if (slave) 547 list_add_tail(&slave->list, &portlist); 548 } 549 spin_unlock_irq(&parportlist_lock); 550 551 /* Let drivers know that new port(s) has arrived. */ 552 attach_driver_chain(port); 553 for (i = 1; i < 3; i++) { 554 struct parport *slave = port->slaves[i-1]; 555 if (slave) 556 attach_driver_chain(slave); 557 } 558 mutex_unlock(®istration_lock); 559 } 560 EXPORT_SYMBOL(parport_announce_port); 561 562 /** 563 * parport_remove_port - deregister a parallel port 564 * @port: parallel port to deregister 565 * 566 * When a parallel port driver is forcibly unloaded, or a 567 * parallel port becomes inaccessible, the port driver must call 568 * this function in order to deal with device drivers that still 569 * want to use it. 570 * 571 * The parport structure associated with the port has its 572 * operations structure replaced with one containing 'null' 573 * operations that return errors or just don't do anything. 574 * 575 * Any drivers that have registered themselves using 576 * parport_register_driver() are notified that the port is no 577 * longer accessible by having their detach() routines called 578 * with @port as the parameter. 579 **/ 580 581 void parport_remove_port(struct parport *port) 582 { 583 int i; 584 585 mutex_lock(®istration_lock); 586 587 /* Spread the word. */ 588 detach_driver_chain(port); 589 590 #ifdef CONFIG_PARPORT_1284 591 /* Forget the IEEE1284.3 topology of the port. */ 592 parport_daisy_fini(port); 593 for (i = 1; i < 3; i++) { 594 struct parport *slave = port->slaves[i-1]; 595 if (!slave) 596 continue; 597 detach_driver_chain(slave); 598 parport_daisy_fini(slave); 599 } 600 #endif 601 602 port->ops = &dead_ops; 603 spin_lock(&parportlist_lock); 604 list_del_init(&port->list); 605 for (i = 1; i < 3; i++) { 606 struct parport *slave = port->slaves[i-1]; 607 if (slave) 608 list_del_init(&slave->list); 609 } 610 spin_unlock(&parportlist_lock); 611 612 mutex_unlock(®istration_lock); 613 614 parport_proc_unregister(port); 615 616 for (i = 1; i < 3; i++) { 617 struct parport *slave = port->slaves[i-1]; 618 if (slave) 619 parport_put_port(slave); 620 } 621 } 622 EXPORT_SYMBOL(parport_remove_port); 623 624 /** 625 * parport_register_device - register a device on a parallel port 626 * @port: port to which the device is attached 627 * @name: a name to refer to the device 628 * @pf: preemption callback 629 * @kf: kick callback (wake-up) 630 * @irq_func: interrupt handler 631 * @flags: registration flags 632 * @handle: data for callback functions 633 * 634 * This function, called by parallel port device drivers, 635 * declares that a device is connected to a port, and tells the 636 * system all it needs to know. 637 * 638 * The @name is allocated by the caller and must not be 639 * deallocated until the caller calls @parport_unregister_device 640 * for that device. 641 * 642 * The preemption callback function, @pf, is called when this 643 * device driver has claimed access to the port but another 644 * device driver wants to use it. It is given @handle as its 645 * parameter, and should return zero if it is willing for the 646 * system to release the port to another driver on its behalf. 647 * If it wants to keep control of the port it should return 648 * non-zero, and no action will be taken. It is good manners for 649 * the driver to try to release the port at the earliest 650 * opportunity after its preemption callback rejects a preemption 651 * attempt. Note that if a preemption callback is happy for 652 * preemption to go ahead, there is no need to release the port; 653 * it is done automatically. This function may not block, as it 654 * may be called from interrupt context. If the device driver 655 * does not support preemption, @pf can be %NULL. 656 * 657 * The wake-up ("kick") callback function, @kf, is called when 658 * the port is available to be claimed for exclusive access; that 659 * is, parport_claim() is guaranteed to succeed when called from 660 * inside the wake-up callback function. If the driver wants to 661 * claim the port it should do so; otherwise, it need not take 662 * any action. This function may not block, as it may be called 663 * from interrupt context. If the device driver does not want to 664 * be explicitly invited to claim the port in this way, @kf can 665 * be %NULL. 666 * 667 * The interrupt handler, @irq_func, is called when an interrupt 668 * arrives from the parallel port. Note that if a device driver 669 * wants to use interrupts it should use parport_enable_irq(), 670 * and can also check the irq member of the parport structure 671 * representing the port. 672 * 673 * The parallel port (lowlevel) driver is the one that has called 674 * request_irq() and whose interrupt handler is called first. 675 * This handler does whatever needs to be done to the hardware to 676 * acknowledge the interrupt (for PC-style ports there is nothing 677 * special to be done). It then tells the IEEE 1284 code about 678 * the interrupt, which may involve reacting to an IEEE 1284 679 * event depending on the current IEEE 1284 phase. After this, 680 * it calls @irq_func. Needless to say, @irq_func will be called 681 * from interrupt context, and may not block. 682 * 683 * The %PARPORT_DEV_EXCL flag is for preventing port sharing, and 684 * so should only be used when sharing the port with other device 685 * drivers is impossible and would lead to incorrect behaviour. 686 * Use it sparingly! Normally, @flags will be zero. 687 * 688 * This function returns a pointer to a structure that represents 689 * the device on the port, or %NULL if there is not enough memory 690 * to allocate space for that structure. 691 **/ 692 693 struct pardevice * 694 parport_register_device(struct parport *port, const char *name, 695 int (*pf)(void *), void (*kf)(void *), 696 void (*irq_func)(void *), 697 int flags, void *handle) 698 { 699 struct pardevice *tmp; 700 701 if (port->physport->flags & PARPORT_FLAG_EXCL) { 702 /* An exclusive device is registered. */ 703 printk(KERN_DEBUG "%s: no more devices allowed\n", 704 port->name); 705 return NULL; 706 } 707 708 if (flags & PARPORT_DEV_LURK) { 709 if (!pf || !kf) { 710 printk(KERN_INFO "%s: refused to register lurking device (%s) without callbacks\n", port->name, name); 711 return NULL; 712 } 713 } 714 715 if (flags & PARPORT_DEV_EXCL) { 716 if (port->physport->devices) { 717 /* 718 * If a device is already registered and this new 719 * device wants exclusive access, then no need to 720 * continue as we can not grant exclusive access to 721 * this device. 722 */ 723 pr_err("%s: cannot grant exclusive access for device %s\n", 724 port->name, name); 725 return NULL; 726 } 727 } 728 729 /* 730 * We up our own module reference count, and that of the port 731 * on which a device is to be registered, to ensure that 732 * neither of us gets unloaded while we sleep in (e.g.) 733 * kmalloc. 734 */ 735 if (!try_module_get(port->ops->owner)) 736 return NULL; 737 738 parport_get_port(port); 739 740 tmp = kmalloc(sizeof(struct pardevice), GFP_KERNEL); 741 if (!tmp) 742 goto out; 743 744 tmp->state = kmalloc(sizeof(struct parport_state), GFP_KERNEL); 745 if (!tmp->state) 746 goto out_free_pardevice; 747 748 tmp->name = name; 749 tmp->port = port; 750 tmp->daisy = -1; 751 tmp->preempt = pf; 752 tmp->wakeup = kf; 753 tmp->private = handle; 754 tmp->flags = flags; 755 tmp->irq_func = irq_func; 756 tmp->waiting = 0; 757 tmp->timeout = 5 * HZ; 758 tmp->devmodel = false; 759 760 /* Chain this onto the list */ 761 tmp->prev = NULL; 762 /* 763 * This function must not run from an irq handler so we don' t need 764 * to clear irq on the local CPU. -arca 765 */ 766 spin_lock(&port->physport->pardevice_lock); 767 768 if (flags & PARPORT_DEV_EXCL) { 769 if (port->physport->devices) { 770 spin_unlock(&port->physport->pardevice_lock); 771 printk(KERN_DEBUG 772 "%s: cannot grant exclusive access for device %s\n", 773 port->name, name); 774 goto out_free_all; 775 } 776 port->flags |= PARPORT_FLAG_EXCL; 777 } 778 779 tmp->next = port->physport->devices; 780 wmb(); /* 781 * Make sure that tmp->next is written before it's 782 * added to the list; see comments marked 'no locking 783 * required' 784 */ 785 if (port->physport->devices) 786 port->physport->devices->prev = tmp; 787 port->physport->devices = tmp; 788 spin_unlock(&port->physport->pardevice_lock); 789 790 init_waitqueue_head(&tmp->wait_q); 791 tmp->timeslice = parport_default_timeslice; 792 tmp->waitnext = tmp->waitprev = NULL; 793 794 /* 795 * This has to be run as last thing since init_state may need other 796 * pardevice fields. -arca 797 */ 798 port->ops->init_state(tmp, tmp->state); 799 if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) { 800 port->proc_device = tmp; 801 parport_device_proc_register(tmp); 802 } 803 return tmp; 804 805 out_free_all: 806 kfree(tmp->state); 807 out_free_pardevice: 808 kfree(tmp); 809 out: 810 parport_put_port(port); 811 module_put(port->ops->owner); 812 813 return NULL; 814 } 815 EXPORT_SYMBOL(parport_register_device); 816 817 static void free_pardevice(struct device *dev) 818 { 819 struct pardevice *par_dev = to_pardevice(dev); 820 821 kfree(par_dev->name); 822 kfree(par_dev); 823 } 824 825 struct pardevice * 826 parport_register_dev_model(struct parport *port, const char *name, 827 const struct pardev_cb *par_dev_cb, int id) 828 { 829 struct pardevice *par_dev; 830 int ret; 831 char *devname; 832 833 if (port->physport->flags & PARPORT_FLAG_EXCL) { 834 /* An exclusive device is registered. */ 835 pr_err("%s: no more devices allowed\n", port->name); 836 return NULL; 837 } 838 839 if (par_dev_cb->flags & PARPORT_DEV_LURK) { 840 if (!par_dev_cb->preempt || !par_dev_cb->wakeup) { 841 pr_info("%s: refused to register lurking device (%s) without callbacks\n", 842 port->name, name); 843 return NULL; 844 } 845 } 846 847 if (par_dev_cb->flags & PARPORT_DEV_EXCL) { 848 if (port->physport->devices) { 849 /* 850 * If a device is already registered and this new 851 * device wants exclusive access, then no need to 852 * continue as we can not grant exclusive access to 853 * this device. 854 */ 855 pr_err("%s: cannot grant exclusive access for device %s\n", 856 port->name, name); 857 return NULL; 858 } 859 } 860 861 if (!try_module_get(port->ops->owner)) 862 return NULL; 863 864 parport_get_port(port); 865 866 par_dev = kzalloc(sizeof(*par_dev), GFP_KERNEL); 867 if (!par_dev) 868 goto err_put_port; 869 870 par_dev->state = kzalloc(sizeof(*par_dev->state), GFP_KERNEL); 871 if (!par_dev->state) 872 goto err_put_par_dev; 873 874 devname = kstrdup(name, GFP_KERNEL); 875 if (!devname) 876 goto err_free_par_dev; 877 878 par_dev->name = devname; 879 par_dev->port = port; 880 par_dev->daisy = -1; 881 par_dev->preempt = par_dev_cb->preempt; 882 par_dev->wakeup = par_dev_cb->wakeup; 883 par_dev->private = par_dev_cb->private; 884 par_dev->flags = par_dev_cb->flags; 885 par_dev->irq_func = par_dev_cb->irq_func; 886 par_dev->waiting = 0; 887 par_dev->timeout = 5 * HZ; 888 889 par_dev->dev.parent = &port->bus_dev; 890 par_dev->dev.bus = &parport_bus_type; 891 ret = dev_set_name(&par_dev->dev, "%s.%d", devname, id); 892 if (ret) 893 goto err_free_devname; 894 par_dev->dev.release = free_pardevice; 895 par_dev->devmodel = true; 896 ret = device_register(&par_dev->dev); 897 if (ret) { 898 put_device(&par_dev->dev); 899 goto err_put_port; 900 } 901 902 /* Chain this onto the list */ 903 par_dev->prev = NULL; 904 /* 905 * This function must not run from an irq handler so we don' t need 906 * to clear irq on the local CPU. -arca 907 */ 908 spin_lock(&port->physport->pardevice_lock); 909 910 if (par_dev_cb->flags & PARPORT_DEV_EXCL) { 911 if (port->physport->devices) { 912 spin_unlock(&port->physport->pardevice_lock); 913 pr_debug("%s: cannot grant exclusive access for device %s\n", 914 port->name, name); 915 device_unregister(&par_dev->dev); 916 goto err_put_port; 917 } 918 port->flags |= PARPORT_FLAG_EXCL; 919 } 920 921 par_dev->next = port->physport->devices; 922 wmb(); /* 923 * Make sure that tmp->next is written before it's 924 * added to the list; see comments marked 'no locking 925 * required' 926 */ 927 if (port->physport->devices) 928 port->physport->devices->prev = par_dev; 929 port->physport->devices = par_dev; 930 spin_unlock(&port->physport->pardevice_lock); 931 932 init_waitqueue_head(&par_dev->wait_q); 933 par_dev->timeslice = parport_default_timeslice; 934 par_dev->waitnext = NULL; 935 par_dev->waitprev = NULL; 936 937 /* 938 * This has to be run as last thing since init_state may need other 939 * pardevice fields. -arca 940 */ 941 port->ops->init_state(par_dev, par_dev->state); 942 if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) { 943 port->proc_device = par_dev; 944 parport_device_proc_register(par_dev); 945 } 946 947 return par_dev; 948 949 err_free_devname: 950 kfree(devname); 951 err_free_par_dev: 952 kfree(par_dev->state); 953 err_put_par_dev: 954 if (!par_dev->devmodel) 955 kfree(par_dev); 956 err_put_port: 957 parport_put_port(port); 958 module_put(port->ops->owner); 959 960 return NULL; 961 } 962 EXPORT_SYMBOL(parport_register_dev_model); 963 964 /** 965 * parport_unregister_device - deregister a device on a parallel port 966 * @dev: pointer to structure representing device 967 * 968 * This undoes the effect of parport_register_device(). 969 **/ 970 971 void parport_unregister_device(struct pardevice *dev) 972 { 973 struct parport *port; 974 975 #ifdef PARPORT_PARANOID 976 if (!dev) { 977 printk(KERN_ERR "parport_unregister_device: passed NULL\n"); 978 return; 979 } 980 #endif 981 982 port = dev->port->physport; 983 984 if (port->proc_device == dev) { 985 port->proc_device = NULL; 986 clear_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags); 987 parport_device_proc_unregister(dev); 988 } 989 990 if (port->cad == dev) { 991 printk(KERN_DEBUG "%s: %s forgot to release port\n", 992 port->name, dev->name); 993 parport_release(dev); 994 } 995 996 spin_lock(&port->pardevice_lock); 997 if (dev->next) 998 dev->next->prev = dev->prev; 999 if (dev->prev) 1000 dev->prev->next = dev->next; 1001 else 1002 port->devices = dev->next; 1003 1004 if (dev->flags & PARPORT_DEV_EXCL) 1005 port->flags &= ~PARPORT_FLAG_EXCL; 1006 1007 spin_unlock(&port->pardevice_lock); 1008 1009 /* 1010 * Make sure we haven't left any pointers around in the wait 1011 * list. 1012 */ 1013 spin_lock_irq(&port->waitlist_lock); 1014 if (dev->waitprev || dev->waitnext || port->waithead == dev) { 1015 if (dev->waitprev) 1016 dev->waitprev->waitnext = dev->waitnext; 1017 else 1018 port->waithead = dev->waitnext; 1019 if (dev->waitnext) 1020 dev->waitnext->waitprev = dev->waitprev; 1021 else 1022 port->waittail = dev->waitprev; 1023 } 1024 spin_unlock_irq(&port->waitlist_lock); 1025 1026 kfree(dev->state); 1027 if (dev->devmodel) 1028 device_unregister(&dev->dev); 1029 else 1030 kfree(dev); 1031 1032 module_put(port->ops->owner); 1033 parport_put_port(port); 1034 } 1035 EXPORT_SYMBOL(parport_unregister_device); 1036 1037 /** 1038 * parport_find_number - find a parallel port by number 1039 * @number: parallel port number 1040 * 1041 * This returns the parallel port with the specified number, or 1042 * %NULL if there is none. 1043 * 1044 * There is an implicit parport_get_port() done already; to throw 1045 * away the reference to the port that parport_find_number() 1046 * gives you, use parport_put_port(). 1047 */ 1048 1049 struct parport *parport_find_number(int number) 1050 { 1051 struct parport *port, *result = NULL; 1052 1053 if (list_empty(&portlist)) 1054 get_lowlevel_driver(); 1055 1056 spin_lock(&parportlist_lock); 1057 list_for_each_entry(port, &portlist, list) { 1058 if (port->number == number) { 1059 result = parport_get_port(port); 1060 break; 1061 } 1062 } 1063 spin_unlock(&parportlist_lock); 1064 return result; 1065 } 1066 EXPORT_SYMBOL(parport_find_number); 1067 1068 /** 1069 * parport_find_base - find a parallel port by base address 1070 * @base: base I/O address 1071 * 1072 * This returns the parallel port with the specified base 1073 * address, or %NULL if there is none. 1074 * 1075 * There is an implicit parport_get_port() done already; to throw 1076 * away the reference to the port that parport_find_base() 1077 * gives you, use parport_put_port(). 1078 */ 1079 1080 struct parport *parport_find_base(unsigned long base) 1081 { 1082 struct parport *port, *result = NULL; 1083 1084 if (list_empty(&portlist)) 1085 get_lowlevel_driver(); 1086 1087 spin_lock(&parportlist_lock); 1088 list_for_each_entry(port, &portlist, list) { 1089 if (port->base == base) { 1090 result = parport_get_port(port); 1091 break; 1092 } 1093 } 1094 spin_unlock(&parportlist_lock); 1095 return result; 1096 } 1097 EXPORT_SYMBOL(parport_find_base); 1098 1099 /** 1100 * parport_claim - claim access to a parallel port device 1101 * @dev: pointer to structure representing a device on the port 1102 * 1103 * This function will not block and so can be used from interrupt 1104 * context. If parport_claim() succeeds in claiming access to 1105 * the port it returns zero and the port is available to use. It 1106 * may fail (returning non-zero) if the port is in use by another 1107 * driver and that driver is not willing to relinquish control of 1108 * the port. 1109 **/ 1110 1111 int parport_claim(struct pardevice *dev) 1112 { 1113 struct pardevice *oldcad; 1114 struct parport *port = dev->port->physport; 1115 unsigned long flags; 1116 1117 if (port->cad == dev) { 1118 printk(KERN_INFO "%s: %s already owner\n", 1119 dev->port->name,dev->name); 1120 return 0; 1121 } 1122 1123 /* Preempt any current device */ 1124 write_lock_irqsave(&port->cad_lock, flags); 1125 oldcad = port->cad; 1126 if (oldcad) { 1127 if (oldcad->preempt) { 1128 if (oldcad->preempt(oldcad->private)) 1129 goto blocked; 1130 port->ops->save_state(port, dev->state); 1131 } else 1132 goto blocked; 1133 1134 if (port->cad != oldcad) { 1135 /* 1136 * I think we'll actually deadlock rather than 1137 * get here, but just in case.. 1138 */ 1139 printk(KERN_WARNING 1140 "%s: %s released port when preempted!\n", 1141 port->name, oldcad->name); 1142 if (port->cad) 1143 goto blocked; 1144 } 1145 } 1146 1147 /* Can't fail from now on, so mark ourselves as no longer waiting. */ 1148 if (dev->waiting & 1) { 1149 dev->waiting = 0; 1150 1151 /* Take ourselves out of the wait list again. */ 1152 spin_lock_irq(&port->waitlist_lock); 1153 if (dev->waitprev) 1154 dev->waitprev->waitnext = dev->waitnext; 1155 else 1156 port->waithead = dev->waitnext; 1157 if (dev->waitnext) 1158 dev->waitnext->waitprev = dev->waitprev; 1159 else 1160 port->waittail = dev->waitprev; 1161 spin_unlock_irq(&port->waitlist_lock); 1162 dev->waitprev = dev->waitnext = NULL; 1163 } 1164 1165 /* Now we do the change of devices */ 1166 port->cad = dev; 1167 1168 #ifdef CONFIG_PARPORT_1284 1169 /* If it's a mux port, select it. */ 1170 if (dev->port->muxport >= 0) { 1171 /* FIXME */ 1172 port->muxsel = dev->port->muxport; 1173 } 1174 1175 /* If it's a daisy chain device, select it. */ 1176 if (dev->daisy >= 0) { 1177 /* This could be lazier. */ 1178 if (!parport_daisy_select(port, dev->daisy, 1179 IEEE1284_MODE_COMPAT)) 1180 port->daisy = dev->daisy; 1181 } 1182 #endif /* IEEE1284.3 support */ 1183 1184 /* Restore control registers */ 1185 port->ops->restore_state(port, dev->state); 1186 write_unlock_irqrestore(&port->cad_lock, flags); 1187 dev->time = jiffies; 1188 return 0; 1189 1190 blocked: 1191 /* 1192 * If this is the first time we tried to claim the port, register an 1193 * interest. This is only allowed for devices sleeping in 1194 * parport_claim_or_block(), or those with a wakeup function. 1195 */ 1196 1197 /* The cad_lock is still held for writing here */ 1198 if (dev->waiting & 2 || dev->wakeup) { 1199 spin_lock(&port->waitlist_lock); 1200 if (test_and_set_bit(0, &dev->waiting) == 0) { 1201 /* First add ourselves to the end of the wait list. */ 1202 dev->waitnext = NULL; 1203 dev->waitprev = port->waittail; 1204 if (port->waittail) { 1205 port->waittail->waitnext = dev; 1206 port->waittail = dev; 1207 } else 1208 port->waithead = port->waittail = dev; 1209 } 1210 spin_unlock(&port->waitlist_lock); 1211 } 1212 write_unlock_irqrestore(&port->cad_lock, flags); 1213 return -EAGAIN; 1214 } 1215 EXPORT_SYMBOL(parport_claim); 1216 1217 /** 1218 * parport_claim_or_block - claim access to a parallel port device 1219 * @dev: pointer to structure representing a device on the port 1220 * 1221 * This behaves like parport_claim(), but will block if necessary 1222 * to wait for the port to be free. A return value of 1 1223 * indicates that it slept; 0 means that it succeeded without 1224 * needing to sleep. A negative error code indicates failure. 1225 **/ 1226 1227 int parport_claim_or_block(struct pardevice *dev) 1228 { 1229 int r; 1230 1231 /* 1232 * Signal to parport_claim() that we can wait even without a 1233 * wakeup function. 1234 */ 1235 dev->waiting = 2; 1236 1237 /* Try to claim the port. If this fails, we need to sleep. */ 1238 r = parport_claim(dev); 1239 if (r == -EAGAIN) { 1240 #ifdef PARPORT_DEBUG_SHARING 1241 printk(KERN_DEBUG "%s: parport_claim() returned -EAGAIN\n", dev->name); 1242 #endif 1243 /* 1244 * FIXME!!! Use the proper locking for dev->waiting, 1245 * and make this use the "wait_event_interruptible()" 1246 * interfaces. The cli/sti that used to be here 1247 * did nothing. 1248 * 1249 * See also parport_release() 1250 */ 1251 1252 /* 1253 * If dev->waiting is clear now, an interrupt 1254 * gave us the port and we would deadlock if we slept. 1255 */ 1256 if (dev->waiting) { 1257 wait_event_interruptible(dev->wait_q, 1258 !dev->waiting); 1259 if (signal_pending(current)) 1260 return -EINTR; 1261 r = 1; 1262 } else { 1263 r = 0; 1264 #ifdef PARPORT_DEBUG_SHARING 1265 printk(KERN_DEBUG "%s: didn't sleep in parport_claim_or_block()\n", 1266 dev->name); 1267 #endif 1268 } 1269 1270 #ifdef PARPORT_DEBUG_SHARING 1271 if (dev->port->physport->cad != dev) 1272 printk(KERN_DEBUG "%s: exiting parport_claim_or_block but %s owns port!\n", 1273 dev->name, dev->port->physport->cad ? 1274 dev->port->physport->cad->name:"nobody"); 1275 #endif 1276 } 1277 dev->waiting = 0; 1278 return r; 1279 } 1280 EXPORT_SYMBOL(parport_claim_or_block); 1281 1282 /** 1283 * parport_release - give up access to a parallel port device 1284 * @dev: pointer to structure representing parallel port device 1285 * 1286 * This function cannot fail, but it should not be called without 1287 * the port claimed. Similarly, if the port is already claimed 1288 * you should not try claiming it again. 1289 **/ 1290 1291 void parport_release(struct pardevice *dev) 1292 { 1293 struct parport *port = dev->port->physport; 1294 struct pardevice *pd; 1295 unsigned long flags; 1296 1297 /* Make sure that dev is the current device */ 1298 write_lock_irqsave(&port->cad_lock, flags); 1299 if (port->cad != dev) { 1300 write_unlock_irqrestore(&port->cad_lock, flags); 1301 printk(KERN_WARNING "%s: %s tried to release parport when not owner\n", 1302 port->name, dev->name); 1303 return; 1304 } 1305 1306 #ifdef CONFIG_PARPORT_1284 1307 /* If this is on a mux port, deselect it. */ 1308 if (dev->port->muxport >= 0) { 1309 /* FIXME */ 1310 port->muxsel = -1; 1311 } 1312 1313 /* If this is a daisy device, deselect it. */ 1314 if (dev->daisy >= 0) { 1315 parport_daisy_deselect_all(port); 1316 port->daisy = -1; 1317 } 1318 #endif 1319 1320 port->cad = NULL; 1321 write_unlock_irqrestore(&port->cad_lock, flags); 1322 1323 /* Save control registers */ 1324 port->ops->save_state(port, dev->state); 1325 1326 /* 1327 * If anybody is waiting, find out who's been there longest and 1328 * then wake them up. (Note: no locking required) 1329 */ 1330 /* !!! LOCKING IS NEEDED HERE */ 1331 for (pd = port->waithead; pd; pd = pd->waitnext) { 1332 if (pd->waiting & 2) { /* sleeping in claim_or_block */ 1333 parport_claim(pd); 1334 if (waitqueue_active(&pd->wait_q)) 1335 wake_up_interruptible(&pd->wait_q); 1336 return; 1337 } else if (pd->wakeup) { 1338 pd->wakeup(pd->private); 1339 if (dev->port->cad) /* racy but no matter */ 1340 return; 1341 } else { 1342 printk(KERN_ERR "%s: don't know how to wake %s\n", port->name, pd->name); 1343 } 1344 } 1345 1346 /* 1347 * Nobody was waiting, so walk the list to see if anyone is 1348 * interested in being woken up. (Note: no locking required) 1349 */ 1350 /* !!! LOCKING IS NEEDED HERE */ 1351 for (pd = port->devices; !port->cad && pd; pd = pd->next) { 1352 if (pd->wakeup && pd != dev) 1353 pd->wakeup(pd->private); 1354 } 1355 } 1356 EXPORT_SYMBOL(parport_release); 1357 1358 irqreturn_t parport_irq_handler(int irq, void *dev_id) 1359 { 1360 struct parport *port = dev_id; 1361 1362 parport_generic_irq(port); 1363 1364 return IRQ_HANDLED; 1365 } 1366 EXPORT_SYMBOL(parport_irq_handler); 1367 1368 MODULE_LICENSE("GPL"); 1369