blob: 8067f54ce050a6c8cf3a4c18d9b4ea560f017d94 [file] [log] [blame]
Adrian Bunk612de102008-10-15 22:04:33 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#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.h>
31#include <linux/kmod.h>
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +053032#include <linux/device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#include <linux/spinlock.h>
Ingo Molnar14cc3e22006-03-26 01:37:14 -080035#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <asm/irq.h>
37
38#undef PARPORT_PARANOID
39
40#define PARPORT_DEFAULT_TIMESLICE (HZ/5)
41
42unsigned long parport_default_timeslice = PARPORT_DEFAULT_TIMESLICE;
43int parport_default_spintime = DEFAULT_SPIN_TIME;
44
45static LIST_HEAD(portlist);
46static DEFINE_SPINLOCK(parportlist_lock);
47
48/* list of all allocated ports, sorted by ->number */
49static LIST_HEAD(all_ports);
50static DEFINE_SPINLOCK(full_list_lock);
51
52static LIST_HEAD(drivers);
53
Ingo Molnar14cc3e22006-03-26 01:37:14 -080054static DEFINE_MUTEX(registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56/* What you can do to a port that's gone away.. */
57static void dead_write_lines (struct parport *p, unsigned char b){}
58static unsigned char dead_read_lines (struct parport *p) { return 0; }
59static unsigned char dead_frob_lines (struct parport *p, unsigned char b,
60 unsigned char c) { return 0; }
61static void dead_onearg (struct parport *p){}
62static void dead_initstate (struct pardevice *d, struct parport_state *s) { }
63static void dead_state (struct parport *p, struct parport_state *s) { }
64static size_t dead_write (struct parport *p, const void *b, size_t l, int f)
65{ return 0; }
66static size_t dead_read (struct parport *p, void *b, size_t l, int f)
67{ return 0; }
68static 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
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530104static struct device_type parport_device_type = {
105 .name = "parport",
106};
107
108static int is_parport(struct device *dev)
109{
110 return dev->type == &parport_device_type;
111}
112
113static 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
133static struct bus_type parport_bus_type = {
134 .name = "parport",
135 .probe = parport_probe,
136};
137
138int parport_bus_init(void)
139{
140 return bus_register(&parport_bus_type);
141}
142
143void 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 regsitered with the bus and decide if it
152 * wants to use this new port.
153 */
154static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164/* Call attach(port) for each registered driver. */
165static void attach_driver_chain(struct parport *port)
166{
167 /* caller has exclusive registration_lock */
168 struct parport_driver *drv;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530169
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 list_for_each_entry(drv, &drivers, list)
171 drv->attach(port);
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530172
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
181static 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189}
190
191/* Call detach(port) for each registered driver. */
192static 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);
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530198
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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205}
206
207/* Ask kmod for some lowlevel drivers. */
208static void get_lowlevel_driver (void)
209{
210 /* There is no actual module called this: you should set
211 * up an alias for modutils. */
212 request_module ("parport_lowlevel");
213}
214
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530215/*
216 * iterates through all the devices connected to the bus and sends the device
217 * details to the match_port callback of the driver, so that the driver can
218 * know what are all the ports that are connected to the bus and choose the
219 * port to which it wants to register its device.
220 */
221static int port_check(struct device *dev, void *dev_drv)
222{
223 struct parport_driver *drv = dev_drv;
224
225 /* only send ports, do not send other devices connected to bus */
226 if (is_parport(dev))
227 drv->match_port(to_parport_dev(dev));
228 return 0;
229}
230
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231/**
232 * parport_register_driver - register a parallel port device driver
233 * @drv: structure describing the driver
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530234 * @owner: owner module of drv
235 * @mod_name: module name string
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 *
237 * This can be called by a parallel port device driver in order
238 * to receive notifications about ports being found in the
239 * system, as well as ports no longer available.
240 *
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530241 * If devmodel is true then the new device model is used
242 * for registration.
243 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 * The @drv structure is allocated by the caller and must not be
245 * deallocated until after calling parport_unregister_driver().
246 *
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530247 * If using the non device model:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 * The driver's attach() function may block. The port that
249 * attach() is given will be valid for the duration of the
250 * callback, but if the driver wants to take a copy of the
251 * pointer it must call parport_get_port() to do so. Calling
252 * parport_register_device() on that port will do this for you.
253 *
254 * The driver's detach() function may block. The port that
255 * detach() is given will be valid for the duration of the
256 * callback, but if the driver wants to take a copy of the
257 * pointer it must call parport_get_port() to do so.
258 *
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530259 *
260 * Returns 0 on success. The non device model will always succeeds.
261 * but the new device model can fail and will return the error code.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 **/
263
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530264int __parport_register_driver(struct parport_driver *drv, struct module *owner,
265 const char *mod_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 if (list_empty(&portlist))
268 get_lowlevel_driver ();
269
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530270 if (drv->devmodel) {
271 /* using device model */
272 int ret;
273
274 /* initialize common driver fields */
275 drv->driver.name = drv->name;
276 drv->driver.bus = &parport_bus_type;
277 drv->driver.owner = owner;
278 drv->driver.mod_name = mod_name;
279 ret = driver_register(&drv->driver);
280 if (ret)
281 return ret;
282
283 mutex_lock(&registration_lock);
284 if (drv->match_port)
285 bus_for_each_dev(&parport_bus_type, NULL, drv,
286 port_check);
287 mutex_unlock(&registration_lock);
288 } else {
289 struct parport *port;
290
291 drv->devmodel = false;
292
293 mutex_lock(&registration_lock);
294 list_for_each_entry(port, &portlist, list)
295 drv->attach(port);
296 list_add(&drv->list, &drivers);
297 mutex_unlock(&registration_lock);
298 }
299
300 return 0;
301}
302EXPORT_SYMBOL(__parport_register_driver);
303
304static int port_detach(struct device *dev, void *_drv)
305{
306 struct parport_driver *drv = _drv;
307
308 if (is_parport(dev) && drv->detach)
309 drv->detach(to_parport_dev(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310
311 return 0;
312}
313
314/**
315 * parport_unregister_driver - deregister a parallel port device driver
316 * @drv: structure describing the driver that was given to
317 * parport_register_driver()
318 *
319 * This should be called by a parallel port device driver that
320 * has registered itself using parport_register_driver() when it
321 * is about to be unloaded.
322 *
323 * When it returns, the driver's attach() routine will no longer
324 * be called, and for each port that attach() was called for, the
325 * detach() routine will have been called.
326 *
327 * All the driver's attach() and detach() calls are guaranteed to have
328 * finished by the time this function returns.
329 **/
330
331void parport_unregister_driver (struct parport_driver *drv)
332{
333 struct parport *port;
334
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800335 mutex_lock(&registration_lock);
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530336 if (drv->devmodel) {
337 bus_for_each_dev(&parport_bus_type, NULL, drv, port_detach);
338 driver_unregister(&drv->driver);
339 } else {
340 list_del_init(&drv->list);
341 list_for_each_entry(port, &portlist, list)
342 drv->detach(port);
343 }
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800344 mutex_unlock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345}
346
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530347static void free_port(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348{
349 int d;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530350 struct parport *port = to_parport_dev(dev);
351
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 spin_lock(&full_list_lock);
353 list_del(&port->full_list);
354 spin_unlock(&full_list_lock);
355 for (d = 0; d < 5; d++) {
Jesper Juhl6044ec82005-11-07 01:01:32 -0800356 kfree(port->probe_info[d].class_name);
357 kfree(port->probe_info[d].mfr);
358 kfree(port->probe_info[d].model);
359 kfree(port->probe_info[d].cmdset);
360 kfree(port->probe_info[d].description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 }
362
363 kfree(port->name);
364 kfree(port);
365}
366
367/**
368 * parport_get_port - increment a port's reference count
369 * @port: the port
370 *
Randy Dunlap7d469722006-06-25 05:49:29 -0700371 * This ensures that a struct parport pointer remains valid
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 * until the matching parport_put_port() call.
373 **/
374
375struct parport *parport_get_port (struct parport *port)
376{
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530377 struct device *dev = get_device(&port->bus_dev);
378
379 return to_parport_dev(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380}
381
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530382void parport_del_port(struct parport *port)
383{
384 device_unregister(&port->bus_dev);
385}
386EXPORT_SYMBOL(parport_del_port);
387
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388/**
389 * parport_put_port - decrement a port's reference count
390 * @port: the port
391 *
392 * This should be called once for each call to parport_get_port(),
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530393 * once the port is no longer needed. When the reference count reaches
394 * zero (port is no longer used), free_port is called.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 **/
396
397void parport_put_port (struct parport *port)
398{
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530399 put_device(&port->bus_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400}
401
402/**
403 * parport_register_port - register a parallel port
404 * @base: base I/O address
405 * @irq: IRQ line
406 * @dma: DMA channel
407 * @ops: pointer to the port driver's port operations structure
408 *
409 * When a parallel port (lowlevel) driver finds a port that
410 * should be made available to parallel port device drivers, it
411 * should call parport_register_port(). The @base, @irq, and
412 * @dma parameters are for the convenience of port drivers, and
413 * for ports where they aren't meaningful needn't be set to
414 * anything special. They can be altered afterwards by adjusting
415 * the relevant members of the parport structure that is returned
416 * and represents the port. They should not be tampered with
417 * after calling parport_announce_port, however.
418 *
419 * If there are parallel port device drivers in the system that
420 * have registered themselves using parport_register_driver(),
421 * they are not told about the port at this time; that is done by
422 * parport_announce_port().
423 *
424 * The @ops structure is allocated by the caller, and must not be
425 * deallocated before calling parport_remove_port().
426 *
427 * If there is no memory to allocate a new parport structure,
428 * this function will return %NULL.
429 **/
430
431struct parport *parport_register_port(unsigned long base, int irq, int dma,
432 struct parport_operations *ops)
433{
434 struct list_head *l;
435 struct parport *tmp;
436 int num;
437 int device;
438 char *name;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530439 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
Alexandru Gheorghiuc32df4e2013-07-03 15:09:09 -0700441 tmp = kzalloc(sizeof(struct parport), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 if (!tmp) {
443 printk(KERN_WARNING "parport: memory squeeze\n");
444 return NULL;
445 }
446
447 /* Init our structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 tmp->base = base;
449 tmp->irq = irq;
450 tmp->dma = dma;
451 tmp->muxport = tmp->daisy = tmp->muxsel = -1;
452 tmp->modes = 0;
453 INIT_LIST_HEAD(&tmp->list);
454 tmp->devices = tmp->cad = NULL;
455 tmp->flags = 0;
456 tmp->ops = ops;
457 tmp->physport = tmp;
458 memset (tmp->probe_info, 0, 5 * sizeof (struct parport_device_info));
459 rwlock_init(&tmp->cad_lock);
460 spin_lock_init(&tmp->waitlist_lock);
461 spin_lock_init(&tmp->pardevice_lock);
462 tmp->ieee1284.mode = IEEE1284_MODE_COMPAT;
463 tmp->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
Thomas Gleixnera529f152010-09-07 14:32:34 +0000464 sema_init(&tmp->ieee1284.irq, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 tmp->spintime = parport_default_spintime;
466 atomic_set (&tmp->ref_count, 1);
467 INIT_LIST_HEAD(&tmp->full_list);
468
469 name = kmalloc(15, GFP_KERNEL);
470 if (!name) {
471 printk(KERN_ERR "parport: memory squeeze\n");
472 kfree(tmp);
473 return NULL;
474 }
475 /* Search for the lowest free parport number. */
476
477 spin_lock(&full_list_lock);
478 for (l = all_ports.next, num = 0; l != &all_ports; l = l->next, num++) {
479 struct parport *p = list_entry(l, struct parport, full_list);
480 if (p->number != num)
481 break;
482 }
483 tmp->portnum = tmp->number = num;
484 list_add_tail(&tmp->full_list, l);
485 spin_unlock(&full_list_lock);
486
487 /*
488 * Now that the portnum is known finish doing the Init.
489 */
490 sprintf(name, "parport%d", tmp->portnum = tmp->number);
491 tmp->name = name;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530492 tmp->bus_dev.bus = &parport_bus_type;
493 tmp->bus_dev.release = free_port;
494 dev_set_name(&tmp->bus_dev, name);
495 tmp->bus_dev.type = &parport_device_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
497 for (device = 0; device < 5; device++)
498 /* assume the worst */
499 tmp->probe_info[device].class = PARPORT_CLASS_LEGACY;
500
501 tmp->waithead = tmp->waittail = NULL;
502
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530503 ret = device_register(&tmp->bus_dev);
504 if (ret) {
505 put_device(&tmp->bus_dev);
506 return NULL;
507 }
508
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 return tmp;
510}
511
512/**
513 * parport_announce_port - tell device drivers about a parallel port
514 * @port: parallel port to announce
515 *
516 * After a port driver has registered a parallel port with
517 * parport_register_port, and performed any necessary
518 * initialisation or adjustments, it should call
519 * parport_announce_port() in order to notify all device drivers
520 * that have called parport_register_driver(). Their attach()
521 * functions will be called, with @port as the parameter.
522 **/
523
524void parport_announce_port (struct parport *port)
525{
526 int i;
527
528#ifdef CONFIG_PARPORT_1284
529 /* Analyse the IEEE1284.3 topology of the port. */
530 parport_daisy_init(port);
531#endif
532
David Brownellc15a3832007-05-08 00:27:35 -0700533 if (!port->dev)
534 printk(KERN_WARNING "%s: fix this legacy "
535 "no-device port driver!\n",
536 port->name);
537
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 parport_proc_register(port);
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800539 mutex_lock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 spin_lock_irq(&parportlist_lock);
541 list_add_tail(&port->list, &portlist);
542 for (i = 1; i < 3; i++) {
543 struct parport *slave = port->slaves[i-1];
544 if (slave)
545 list_add_tail(&slave->list, &portlist);
546 }
547 spin_unlock_irq(&parportlist_lock);
548
549 /* Let drivers know that new port(s) has arrived. */
550 attach_driver_chain (port);
551 for (i = 1; i < 3; i++) {
552 struct parport *slave = port->slaves[i-1];
553 if (slave)
554 attach_driver_chain(slave);
555 }
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800556 mutex_unlock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557}
558
559/**
560 * parport_remove_port - deregister a parallel port
561 * @port: parallel port to deregister
562 *
563 * When a parallel port driver is forcibly unloaded, or a
564 * parallel port becomes inaccessible, the port driver must call
565 * this function in order to deal with device drivers that still
566 * want to use it.
567 *
568 * The parport structure associated with the port has its
569 * operations structure replaced with one containing 'null'
570 * operations that return errors or just don't do anything.
571 *
572 * Any drivers that have registered themselves using
573 * parport_register_driver() are notified that the port is no
574 * longer accessible by having their detach() routines called
575 * with @port as the parameter.
576 **/
577
578void parport_remove_port(struct parport *port)
579{
580 int i;
581
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800582 mutex_lock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583
584 /* Spread the word. */
585 detach_driver_chain (port);
586
587#ifdef CONFIG_PARPORT_1284
588 /* Forget the IEEE1284.3 topology of the port. */
589 parport_daisy_fini(port);
590 for (i = 1; i < 3; i++) {
591 struct parport *slave = port->slaves[i-1];
592 if (!slave)
593 continue;
594 detach_driver_chain(slave);
595 parport_daisy_fini(slave);
596 }
597#endif
598
599 port->ops = &dead_ops;
600 spin_lock(&parportlist_lock);
601 list_del_init(&port->list);
602 for (i = 1; i < 3; i++) {
603 struct parport *slave = port->slaves[i-1];
604 if (slave)
605 list_del_init(&slave->list);
606 }
607 spin_unlock(&parportlist_lock);
608
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800609 mutex_unlock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610
611 parport_proc_unregister(port);
612
613 for (i = 1; i < 3; i++) {
614 struct parport *slave = port->slaves[i-1];
615 if (slave)
616 parport_put_port(slave);
617 }
618}
619
620/**
621 * parport_register_device - register a device on a parallel port
622 * @port: port to which the device is attached
623 * @name: a name to refer to the device
624 * @pf: preemption callback
625 * @kf: kick callback (wake-up)
626 * @irq_func: interrupt handler
627 * @flags: registration flags
628 * @handle: data for callback functions
629 *
630 * This function, called by parallel port device drivers,
631 * declares that a device is connected to a port, and tells the
632 * system all it needs to know.
633 *
634 * The @name is allocated by the caller and must not be
635 * deallocated until the caller calls @parport_unregister_device
636 * for that device.
637 *
638 * The preemption callback function, @pf, is called when this
639 * device driver has claimed access to the port but another
640 * device driver wants to use it. It is given @handle as its
641 * parameter, and should return zero if it is willing for the
642 * system to release the port to another driver on its behalf.
643 * If it wants to keep control of the port it should return
644 * non-zero, and no action will be taken. It is good manners for
645 * the driver to try to release the port at the earliest
646 * opportunity after its preemption callback rejects a preemption
647 * attempt. Note that if a preemption callback is happy for
648 * preemption to go ahead, there is no need to release the port;
649 * it is done automatically. This function may not block, as it
650 * may be called from interrupt context. If the device driver
651 * does not support preemption, @pf can be %NULL.
652 *
653 * The wake-up ("kick") callback function, @kf, is called when
654 * the port is available to be claimed for exclusive access; that
655 * is, parport_claim() is guaranteed to succeed when called from
656 * inside the wake-up callback function. If the driver wants to
657 * claim the port it should do so; otherwise, it need not take
658 * any action. This function may not block, as it may be called
659 * from interrupt context. If the device driver does not want to
660 * be explicitly invited to claim the port in this way, @kf can
661 * be %NULL.
662 *
663 * The interrupt handler, @irq_func, is called when an interrupt
664 * arrives from the parallel port. Note that if a device driver
665 * wants to use interrupts it should use parport_enable_irq(),
666 * and can also check the irq member of the parport structure
667 * representing the port.
668 *
669 * The parallel port (lowlevel) driver is the one that has called
670 * request_irq() and whose interrupt handler is called first.
671 * This handler does whatever needs to be done to the hardware to
672 * acknowledge the interrupt (for PC-style ports there is nothing
673 * special to be done). It then tells the IEEE 1284 code about
674 * the interrupt, which may involve reacting to an IEEE 1284
675 * event depending on the current IEEE 1284 phase. After this,
676 * it calls @irq_func. Needless to say, @irq_func will be called
677 * from interrupt context, and may not block.
678 *
679 * The %PARPORT_DEV_EXCL flag is for preventing port sharing, and
680 * so should only be used when sharing the port with other device
681 * drivers is impossible and would lead to incorrect behaviour.
682 * Use it sparingly! Normally, @flags will be zero.
683 *
684 * This function returns a pointer to a structure that represents
685 * the device on the port, or %NULL if there is not enough memory
686 * to allocate space for that structure.
687 **/
688
689struct pardevice *
690parport_register_device(struct parport *port, const char *name,
691 int (*pf)(void *), void (*kf)(void *),
Jeff Garzik5712cb32007-10-19 02:54:26 -0400692 void (*irq_func)(void *),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 int flags, void *handle)
694{
695 struct pardevice *tmp;
696
697 if (port->physport->flags & PARPORT_FLAG_EXCL) {
698 /* An exclusive device is registered. */
699 printk (KERN_DEBUG "%s: no more devices allowed\n",
700 port->name);
701 return NULL;
702 }
703
704 if (flags & PARPORT_DEV_LURK) {
705 if (!pf || !kf) {
706 printk(KERN_INFO "%s: refused to register lurking device (%s) without callbacks\n", port->name, name);
707 return NULL;
708 }
709 }
710
Sudip Mukherjee50566ac82015-06-12 15:20:20 +0530711 if (flags & PARPORT_DEV_EXCL) {
712 if (port->physport->devices) {
713 /*
714 * If a device is already registered and this new
715 * device wants exclusive access, then no need to
716 * continue as we can not grant exclusive access to
717 * this device.
718 */
719 pr_err("%s: cannot grant exclusive access for device %s\n",
720 port->name, name);
721 return NULL;
722 }
723 }
724
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 /* We up our own module reference count, and that of the port
726 on which a device is to be registered, to ensure that
727 neither of us gets unloaded while we sleep in (e.g.)
728 kmalloc.
729 */
730 if (!try_module_get(port->ops->owner)) {
731 return NULL;
732 }
733
734 parport_get_port (port);
735
736 tmp = kmalloc(sizeof(struct pardevice), GFP_KERNEL);
737 if (tmp == NULL) {
738 printk(KERN_WARNING "%s: memory squeeze, couldn't register %s.\n", port->name, name);
739 goto out;
740 }
741
742 tmp->state = kmalloc(sizeof(struct parport_state), GFP_KERNEL);
743 if (tmp->state == NULL) {
744 printk(KERN_WARNING "%s: memory squeeze, couldn't register %s.\n", port->name, name);
745 goto out_free_pardevice;
746 }
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;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530758 tmp->devmodel = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
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 "
773 "device %s\n", 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(); /* Make sure that tmp->next is written before it's
781 added to the list; see comments marked 'no locking
782 required' */
783 if (port->physport->devices)
784 port->physport->devices->prev = tmp;
785 port->physport->devices = tmp;
786 spin_unlock(&port->physport->pardevice_lock);
787
788 init_waitqueue_head(&tmp->wait_q);
789 tmp->timeslice = parport_default_timeslice;
790 tmp->waitnext = tmp->waitprev = NULL;
791
792 /*
793 * This has to be run as last thing since init_state may need other
794 * pardevice fields. -arca
795 */
796 port->ops->init_state(tmp, tmp->state);
Alan Cox05ad7092009-06-02 16:58:10 +0100797 if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) {
798 port->proc_device = tmp;
799 parport_device_proc_register(tmp);
800 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 return tmp;
802
803 out_free_all:
Jesper Juhl6044ec82005-11-07 01:01:32 -0800804 kfree(tmp->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 out_free_pardevice:
Jesper Juhl6044ec82005-11-07 01:01:32 -0800806 kfree(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 out:
808 parport_put_port (port);
809 module_put(port->ops->owner);
810
811 return NULL;
812}
813
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530814static void free_pardevice(struct device *dev)
815{
816 struct pardevice *par_dev = to_pardevice(dev);
817
818 kfree(par_dev->name);
819 kfree(par_dev);
820}
821
822struct pardevice *
823parport_register_dev_model(struct parport *port, const char *name,
824 const struct pardev_cb *par_dev_cb, int id)
825{
826 struct pardevice *par_dev;
827 int ret;
828 char *devname;
829
830 if (port->physport->flags & PARPORT_FLAG_EXCL) {
831 /* An exclusive device is registered. */
832 pr_err("%s: no more devices allowed\n", port->name);
833 return NULL;
834 }
835
836 if (par_dev_cb->flags & PARPORT_DEV_LURK) {
837 if (!par_dev_cb->preempt || !par_dev_cb->wakeup) {
838 pr_info("%s: refused to register lurking device (%s) without callbacks\n",
839 port->name, name);
840 return NULL;
841 }
842 }
843
Sudip Mukherjee50566ac82015-06-12 15:20:20 +0530844 if (par_dev_cb->flags & PARPORT_DEV_EXCL) {
845 if (port->physport->devices) {
846 /*
847 * If a device is already registered and this new
848 * device wants exclusive access, then no need to
849 * continue as we can not grant exclusive access to
850 * this device.
851 */
852 pr_err("%s: cannot grant exclusive access for device %s\n",
853 port->name, name);
854 return NULL;
855 }
856 }
857
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530858 if (!try_module_get(port->ops->owner))
859 return NULL;
860
861 parport_get_port(port);
862
863 par_dev = kzalloc(sizeof(*par_dev), GFP_KERNEL);
864 if (!par_dev)
865 goto err_put_port;
866
867 par_dev->state = kzalloc(sizeof(*par_dev->state), GFP_KERNEL);
868 if (!par_dev->state)
869 goto err_put_par_dev;
870
871 devname = kstrdup(name, GFP_KERNEL);
872 if (!devname)
873 goto err_free_par_dev;
874
875 par_dev->name = devname;
876 par_dev->port = port;
877 par_dev->daisy = -1;
878 par_dev->preempt = par_dev_cb->preempt;
879 par_dev->wakeup = par_dev_cb->wakeup;
880 par_dev->private = par_dev_cb->private;
881 par_dev->flags = par_dev_cb->flags;
882 par_dev->irq_func = par_dev_cb->irq_func;
883 par_dev->waiting = 0;
884 par_dev->timeout = 5 * HZ;
885
886 par_dev->dev.parent = &port->bus_dev;
887 par_dev->dev.bus = &parport_bus_type;
888 ret = dev_set_name(&par_dev->dev, "%s.%d", devname, id);
889 if (ret)
890 goto err_free_devname;
891 par_dev->dev.release = free_pardevice;
892 par_dev->devmodel = true;
893 ret = device_register(&par_dev->dev);
894 if (ret)
895 goto err_put_dev;
896
897 /* Chain this onto the list */
898 par_dev->prev = NULL;
899 /*
900 * This function must not run from an irq handler so we don' t need
901 * to clear irq on the local CPU. -arca
902 */
903 spin_lock(&port->physport->pardevice_lock);
904
905 if (par_dev_cb->flags & PARPORT_DEV_EXCL) {
906 if (port->physport->devices) {
907 spin_unlock(&port->physport->pardevice_lock);
908 pr_debug("%s: cannot grant exclusive access for device %s\n",
909 port->name, name);
910 goto err_put_dev;
911 }
912 port->flags |= PARPORT_FLAG_EXCL;
913 }
914
915 par_dev->next = port->physport->devices;
916 wmb(); /*
917 * Make sure that tmp->next is written before it's
918 * added to the list; see comments marked 'no locking
919 * required'
920 */
921 if (port->physport->devices)
922 port->physport->devices->prev = par_dev;
923 port->physport->devices = par_dev;
924 spin_unlock(&port->physport->pardevice_lock);
925
926 init_waitqueue_head(&par_dev->wait_q);
927 par_dev->timeslice = parport_default_timeslice;
928 par_dev->waitnext = NULL;
929 par_dev->waitprev = NULL;
930
931 /*
932 * This has to be run as last thing since init_state may need other
933 * pardevice fields. -arca
934 */
935 port->ops->init_state(par_dev, par_dev->state);
936 port->proc_device = par_dev;
937 parport_device_proc_register(par_dev);
938
939 return par_dev;
940
941err_put_dev:
942 put_device(&par_dev->dev);
943err_free_devname:
944 kfree(devname);
945err_free_par_dev:
946 kfree(par_dev->state);
947err_put_par_dev:
948 if (!par_dev->devmodel)
949 kfree(par_dev);
950err_put_port:
951 parport_put_port(port);
952 module_put(port->ops->owner);
953
954 return NULL;
955}
956EXPORT_SYMBOL(parport_register_dev_model);
957
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958/**
959 * parport_unregister_device - deregister a device on a parallel port
960 * @dev: pointer to structure representing device
961 *
962 * This undoes the effect of parport_register_device().
963 **/
964
965void parport_unregister_device(struct pardevice *dev)
966{
967 struct parport *port;
968
969#ifdef PARPORT_PARANOID
970 if (dev == NULL) {
971 printk(KERN_ERR "parport_unregister_device: passed NULL\n");
972 return;
973 }
974#endif
975
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 port = dev->port->physport;
977
Alan Cox05ad7092009-06-02 16:58:10 +0100978 if (port->proc_device == dev) {
979 port->proc_device = NULL;
980 clear_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags);
981 parport_device_proc_unregister(dev);
982 }
983
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 if (port->cad == dev) {
985 printk(KERN_DEBUG "%s: %s forgot to release port\n",
986 port->name, dev->name);
987 parport_release (dev);
988 }
989
990 spin_lock(&port->pardevice_lock);
991 if (dev->next)
992 dev->next->prev = dev->prev;
993 if (dev->prev)
994 dev->prev->next = dev->next;
995 else
996 port->devices = dev->next;
997
998 if (dev->flags & PARPORT_DEV_EXCL)
999 port->flags &= ~PARPORT_FLAG_EXCL;
1000
1001 spin_unlock(&port->pardevice_lock);
1002
1003 /* Make sure we haven't left any pointers around in the wait
1004 * list. */
Alexander Gordeevcbeb4b72011-01-25 15:07:16 -08001005 spin_lock_irq(&port->waitlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006 if (dev->waitprev || dev->waitnext || port->waithead == dev) {
1007 if (dev->waitprev)
1008 dev->waitprev->waitnext = dev->waitnext;
1009 else
1010 port->waithead = dev->waitnext;
1011 if (dev->waitnext)
1012 dev->waitnext->waitprev = dev->waitprev;
1013 else
1014 port->waittail = dev->waitprev;
1015 }
Alexander Gordeevcbeb4b72011-01-25 15:07:16 -08001016 spin_unlock_irq(&port->waitlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017
1018 kfree(dev->state);
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +05301019 if (dev->devmodel)
1020 device_unregister(&dev->dev);
1021 else
1022 kfree(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023
1024 module_put(port->ops->owner);
1025 parport_put_port (port);
1026}
1027
1028/**
1029 * parport_find_number - find a parallel port by number
1030 * @number: parallel port number
1031 *
1032 * This returns the parallel port with the specified number, or
1033 * %NULL if there is none.
1034 *
1035 * There is an implicit parport_get_port() done already; to throw
1036 * away the reference to the port that parport_find_number()
1037 * gives you, use parport_put_port().
1038 */
1039
1040struct parport *parport_find_number (int number)
1041{
1042 struct parport *port, *result = NULL;
1043
1044 if (list_empty(&portlist))
1045 get_lowlevel_driver ();
1046
1047 spin_lock (&parportlist_lock);
1048 list_for_each_entry(port, &portlist, list) {
1049 if (port->number == number) {
1050 result = parport_get_port (port);
1051 break;
1052 }
1053 }
1054 spin_unlock (&parportlist_lock);
1055 return result;
1056}
1057
1058/**
1059 * parport_find_base - find a parallel port by base address
1060 * @base: base I/O address
1061 *
1062 * This returns the parallel port with the specified base
1063 * address, or %NULL if there is none.
1064 *
1065 * There is an implicit parport_get_port() done already; to throw
1066 * away the reference to the port that parport_find_base()
1067 * gives you, use parport_put_port().
1068 */
1069
1070struct parport *parport_find_base (unsigned long base)
1071{
1072 struct parport *port, *result = NULL;
1073
1074 if (list_empty(&portlist))
1075 get_lowlevel_driver ();
1076
1077 spin_lock (&parportlist_lock);
1078 list_for_each_entry(port, &portlist, list) {
1079 if (port->base == base) {
1080 result = parport_get_port (port);
1081 break;
1082 }
1083 }
1084 spin_unlock (&parportlist_lock);
1085 return result;
1086}
1087
1088/**
1089 * parport_claim - claim access to a parallel port device
1090 * @dev: pointer to structure representing a device on the port
1091 *
1092 * This function will not block and so can be used from interrupt
1093 * context. If parport_claim() succeeds in claiming access to
1094 * the port it returns zero and the port is available to use. It
1095 * may fail (returning non-zero) if the port is in use by another
1096 * driver and that driver is not willing to relinquish control of
1097 * the port.
1098 **/
1099
1100int parport_claim(struct pardevice *dev)
1101{
1102 struct pardevice *oldcad;
1103 struct parport *port = dev->port->physport;
1104 unsigned long flags;
1105
1106 if (port->cad == dev) {
1107 printk(KERN_INFO "%s: %s already owner\n",
1108 dev->port->name,dev->name);
1109 return 0;
1110 }
1111
1112 /* Preempt any current device */
1113 write_lock_irqsave (&port->cad_lock, flags);
1114 if ((oldcad = port->cad) != NULL) {
1115 if (oldcad->preempt) {
1116 if (oldcad->preempt(oldcad->private))
1117 goto blocked;
1118 port->ops->save_state(port, dev->state);
1119 } else
1120 goto blocked;
1121
1122 if (port->cad != oldcad) {
1123 /* I think we'll actually deadlock rather than
1124 get here, but just in case.. */
1125 printk(KERN_WARNING
1126 "%s: %s released port when preempted!\n",
1127 port->name, oldcad->name);
1128 if (port->cad)
1129 goto blocked;
1130 }
1131 }
1132
1133 /* Can't fail from now on, so mark ourselves as no longer waiting. */
1134 if (dev->waiting & 1) {
1135 dev->waiting = 0;
1136
1137 /* Take ourselves out of the wait list again. */
1138 spin_lock_irq (&port->waitlist_lock);
1139 if (dev->waitprev)
1140 dev->waitprev->waitnext = dev->waitnext;
1141 else
1142 port->waithead = dev->waitnext;
1143 if (dev->waitnext)
1144 dev->waitnext->waitprev = dev->waitprev;
1145 else
1146 port->waittail = dev->waitprev;
1147 spin_unlock_irq (&port->waitlist_lock);
1148 dev->waitprev = dev->waitnext = NULL;
1149 }
1150
1151 /* Now we do the change of devices */
1152 port->cad = dev;
1153
1154#ifdef CONFIG_PARPORT_1284
1155 /* If it's a mux port, select it. */
1156 if (dev->port->muxport >= 0) {
1157 /* FIXME */
1158 port->muxsel = dev->port->muxport;
1159 }
1160
1161 /* If it's a daisy chain device, select it. */
1162 if (dev->daisy >= 0) {
1163 /* This could be lazier. */
1164 if (!parport_daisy_select (port, dev->daisy,
1165 IEEE1284_MODE_COMPAT))
1166 port->daisy = dev->daisy;
1167 }
1168#endif /* IEEE1284.3 support */
1169
1170 /* Restore control registers */
1171 port->ops->restore_state(port, dev->state);
1172 write_unlock_irqrestore(&port->cad_lock, flags);
1173 dev->time = jiffies;
1174 return 0;
1175
1176blocked:
1177 /* If this is the first time we tried to claim the port, register an
1178 interest. This is only allowed for devices sleeping in
1179 parport_claim_or_block(), or those with a wakeup function. */
1180
1181 /* The cad_lock is still held for writing here */
1182 if (dev->waiting & 2 || dev->wakeup) {
1183 spin_lock (&port->waitlist_lock);
1184 if (test_and_set_bit(0, &dev->waiting) == 0) {
1185 /* First add ourselves to the end of the wait list. */
1186 dev->waitnext = NULL;
1187 dev->waitprev = port->waittail;
1188 if (port->waittail) {
1189 port->waittail->waitnext = dev;
1190 port->waittail = dev;
1191 } else
1192 port->waithead = port->waittail = dev;
1193 }
1194 spin_unlock (&port->waitlist_lock);
1195 }
1196 write_unlock_irqrestore (&port->cad_lock, flags);
1197 return -EAGAIN;
1198}
1199
1200/**
1201 * parport_claim_or_block - claim access to a parallel port device
1202 * @dev: pointer to structure representing a device on the port
1203 *
1204 * This behaves like parport_claim(), but will block if necessary
1205 * to wait for the port to be free. A return value of 1
1206 * indicates that it slept; 0 means that it succeeded without
1207 * needing to sleep. A negative error code indicates failure.
1208 **/
1209
1210int parport_claim_or_block(struct pardevice *dev)
1211{
1212 int r;
1213
1214 /* Signal to parport_claim() that we can wait even without a
1215 wakeup function. */
1216 dev->waiting = 2;
1217
1218 /* Try to claim the port. If this fails, we need to sleep. */
1219 r = parport_claim(dev);
1220 if (r == -EAGAIN) {
1221#ifdef PARPORT_DEBUG_SHARING
1222 printk(KERN_DEBUG "%s: parport_claim() returned -EAGAIN\n", dev->name);
1223#endif
1224 /*
1225 * FIXME!!! Use the proper locking for dev->waiting,
1226 * and make this use the "wait_event_interruptible()"
1227 * interfaces. The cli/sti that used to be here
1228 * did nothing.
1229 *
1230 * See also parport_release()
1231 */
1232
1233 /* If dev->waiting is clear now, an interrupt
1234 gave us the port and we would deadlock if we slept. */
1235 if (dev->waiting) {
Arnd Bergmann76ae0532014-02-26 12:01:49 +01001236 wait_event_interruptible(dev->wait_q,
1237 !dev->waiting);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238 if (signal_pending (current)) {
1239 return -EINTR;
1240 }
1241 r = 1;
1242 } else {
1243 r = 0;
1244#ifdef PARPORT_DEBUG_SHARING
1245 printk(KERN_DEBUG "%s: didn't sleep in parport_claim_or_block()\n",
1246 dev->name);
1247#endif
1248 }
1249
1250#ifdef PARPORT_DEBUG_SHARING
1251 if (dev->port->physport->cad != dev)
1252 printk(KERN_DEBUG "%s: exiting parport_claim_or_block "
1253 "but %s owns port!\n", dev->name,
1254 dev->port->physport->cad ?
1255 dev->port->physport->cad->name:"nobody");
1256#endif
1257 }
1258 dev->waiting = 0;
1259 return r;
1260}
1261
1262/**
1263 * parport_release - give up access to a parallel port device
1264 * @dev: pointer to structure representing parallel port device
1265 *
1266 * This function cannot fail, but it should not be called without
1267 * the port claimed. Similarly, if the port is already claimed
1268 * you should not try claiming it again.
1269 **/
1270
1271void parport_release(struct pardevice *dev)
1272{
1273 struct parport *port = dev->port->physport;
1274 struct pardevice *pd;
1275 unsigned long flags;
1276
1277 /* Make sure that dev is the current device */
1278 write_lock_irqsave(&port->cad_lock, flags);
1279 if (port->cad != dev) {
1280 write_unlock_irqrestore (&port->cad_lock, flags);
1281 printk(KERN_WARNING "%s: %s tried to release parport "
1282 "when not owner\n", port->name, dev->name);
1283 return;
1284 }
1285
1286#ifdef CONFIG_PARPORT_1284
1287 /* If this is on a mux port, deselect it. */
1288 if (dev->port->muxport >= 0) {
1289 /* FIXME */
1290 port->muxsel = -1;
1291 }
1292
1293 /* If this is a daisy device, deselect it. */
1294 if (dev->daisy >= 0) {
1295 parport_daisy_deselect_all (port);
1296 port->daisy = -1;
1297 }
1298#endif
1299
1300 port->cad = NULL;
1301 write_unlock_irqrestore(&port->cad_lock, flags);
1302
1303 /* Save control registers */
1304 port->ops->save_state(port, dev->state);
1305
1306 /* If anybody is waiting, find out who's been there longest and
1307 then wake them up. (Note: no locking required) */
1308 /* !!! LOCKING IS NEEDED HERE */
1309 for (pd = port->waithead; pd; pd = pd->waitnext) {
1310 if (pd->waiting & 2) { /* sleeping in claim_or_block */
1311 parport_claim(pd);
1312 if (waitqueue_active(&pd->wait_q))
1313 wake_up_interruptible(&pd->wait_q);
1314 return;
1315 } else if (pd->wakeup) {
1316 pd->wakeup(pd->private);
1317 if (dev->port->cad) /* racy but no matter */
1318 return;
1319 } else {
1320 printk(KERN_ERR "%s: don't know how to wake %s\n", port->name, pd->name);
1321 }
1322 }
1323
1324 /* Nobody was waiting, so walk the list to see if anyone is
1325 interested in being woken up. (Note: no locking required) */
1326 /* !!! LOCKING IS NEEDED HERE */
1327 for (pd = port->devices; (port->cad == NULL) && pd; pd = pd->next) {
1328 if (pd->wakeup && pd != dev)
1329 pd->wakeup(pd->private);
1330 }
1331}
1332
Jeff Garzik3f2e40d2007-10-19 01:42:14 -04001333irqreturn_t parport_irq_handler(int irq, void *dev_id)
1334{
1335 struct parport *port = dev_id;
1336
Jeff Garzikf230d102007-10-19 01:56:02 -04001337 parport_generic_irq(port);
Jeff Garzik3f2e40d2007-10-19 01:42:14 -04001338
1339 return IRQ_HANDLED;
1340}
1341
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342/* Exported symbols for modules. */
1343
1344EXPORT_SYMBOL(parport_claim);
1345EXPORT_SYMBOL(parport_claim_or_block);
1346EXPORT_SYMBOL(parport_release);
1347EXPORT_SYMBOL(parport_register_port);
1348EXPORT_SYMBOL(parport_announce_port);
1349EXPORT_SYMBOL(parport_remove_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350EXPORT_SYMBOL(parport_unregister_driver);
1351EXPORT_SYMBOL(parport_register_device);
1352EXPORT_SYMBOL(parport_unregister_device);
Marko Kohtala94b82092006-01-06 00:19:51 -08001353EXPORT_SYMBOL(parport_get_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354EXPORT_SYMBOL(parport_put_port);
1355EXPORT_SYMBOL(parport_find_number);
1356EXPORT_SYMBOL(parport_find_base);
Jeff Garzik3f2e40d2007-10-19 01:42:14 -04001357EXPORT_SYMBOL(parport_irq_handler);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001358
1359MODULE_LICENSE("GPL");