Commit | Line | Data |
---|---|---|
612de10d | 1 | /* |
1da177e4 | 2 | * Parallel-port resource manager code. |
657e24d3 | 3 | * |
1da177e4 LT |
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 | ||
1da177e4 LT |
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> | |
174cd4b1 | 30 | #include <linux/sched/signal.h> |
1da177e4 | 31 | #include <linux/kmod.h> |
6fa45a22 | 32 | #include <linux/device.h> |
1da177e4 LT |
33 | |
34 | #include <linux/spinlock.h> | |
14cc3e2b | 35 | #include <linux/mutex.h> |
1da177e4 LT |
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 | ||
14cc3e2b | 54 | static DEFINE_MUTEX(registration_lock); |
1da177e4 LT |
55 | |
56 | /* What you can do to a port that's gone away.. */ | |
e732b93c SM |
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, | |
1da177e4 | 60 | unsigned char c) { return 0; } |
e732b93c SM |
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) | |
1da177e4 | 65 | { return 0; } |
e732b93c | 66 | static size_t dead_read(struct parport *p, void *b, size_t l, int f) |
1da177e4 LT |
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, | |
657e24d3 | 96 | |
1da177e4 LT |
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 | ||
6fa45a22 SM |
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 | { | |
a3ac7917 | 140 | return bus_register(&parport_bus_type); |
6fa45a22 SM |
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 | |
e9527365 | 151 | * know about the new port that just registered with the bus and decide if it |
6fa45a22 SM |
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 | ||
1da177e4 LT |
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; | |
6fa45a22 | 169 | |
1da177e4 LT |
170 | list_for_each_entry(drv, &drivers, list) |
171 | drv->attach(port); | |
6fa45a22 SM |
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; | |
1da177e4 LT |
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) | |
e732b93c | 197 | drv->detach(port); |
6fa45a22 SM |
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); | |
1da177e4 LT |
205 | } |
206 | ||
207 | /* Ask kmod for some lowlevel drivers. */ | |
e732b93c | 208 | static void get_lowlevel_driver(void) |
1da177e4 | 209 | { |
7b7a0a30 SM |
210 | /* |
211 | * There is no actual module called this: you should set | |
212 | * up an alias for modutils. | |
213 | */ | |
e732b93c | 214 | request_module("parport_lowlevel"); |
1da177e4 LT |
215 | } |
216 | ||
6fa45a22 SM |
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 | ||
231ec2f2 SM |
233 | /* |
234 | * Iterates through all the devices connected to the bus and return 1 | |
235 | * if the device is a parallel port. | |
236 | */ | |
237 | ||
238 | static int port_detect(struct device *dev, void *dev_drv) | |
239 | { | |
240 | if (is_parport(dev)) | |
241 | return 1; | |
242 | return 0; | |
243 | } | |
244 | ||
1da177e4 LT |
245 | /** |
246 | * parport_register_driver - register a parallel port device driver | |
247 | * @drv: structure describing the driver | |
6fa45a22 SM |
248 | * @owner: owner module of drv |
249 | * @mod_name: module name string | |
1da177e4 LT |
250 | * |
251 | * This can be called by a parallel port device driver in order | |
252 | * to receive notifications about ports being found in the | |
253 | * system, as well as ports no longer available. | |
254 | * | |
6fa45a22 SM |
255 | * If devmodel is true then the new device model is used |
256 | * for registration. | |
257 | * | |
1da177e4 LT |
258 | * The @drv structure is allocated by the caller and must not be |
259 | * deallocated until after calling parport_unregister_driver(). | |
260 | * | |
6fa45a22 | 261 | * If using the non device model: |
1da177e4 LT |
262 | * The driver's attach() function may block. The port that |
263 | * attach() is given will be valid for the duration of the | |
264 | * callback, but if the driver wants to take a copy of the | |
265 | * pointer it must call parport_get_port() to do so. Calling | |
266 | * parport_register_device() on that port will do this for you. | |
267 | * | |
268 | * The driver's detach() function may block. The port that | |
269 | * detach() is given will be valid for the duration of the | |
270 | * callback, but if the driver wants to take a copy of the | |
271 | * pointer it must call parport_get_port() to do so. | |
272 | * | |
6fa45a22 SM |
273 | * |
274 | * Returns 0 on success. The non device model will always succeeds. | |
275 | * but the new device model can fail and will return the error code. | |
1da177e4 LT |
276 | **/ |
277 | ||
6fa45a22 SM |
278 | int __parport_register_driver(struct parport_driver *drv, struct module *owner, |
279 | const char *mod_name) | |
1da177e4 | 280 | { |
6fa45a22 SM |
281 | if (drv->devmodel) { |
282 | /* using device model */ | |
283 | int ret; | |
284 | ||
285 | /* initialize common driver fields */ | |
286 | drv->driver.name = drv->name; | |
287 | drv->driver.bus = &parport_bus_type; | |
288 | drv->driver.owner = owner; | |
289 | drv->driver.mod_name = mod_name; | |
290 | ret = driver_register(&drv->driver); | |
291 | if (ret) | |
292 | return ret; | |
293 | ||
231ec2f2 SM |
294 | /* |
295 | * check if bus has any parallel port registered, if | |
296 | * none is found then load the lowlevel driver. | |
297 | */ | |
298 | ret = bus_for_each_dev(&parport_bus_type, NULL, NULL, | |
299 | port_detect); | |
300 | if (!ret) | |
301 | get_lowlevel_driver(); | |
302 | ||
6fa45a22 SM |
303 | mutex_lock(®istration_lock); |
304 | if (drv->match_port) | |
305 | bus_for_each_dev(&parport_bus_type, NULL, drv, | |
306 | port_check); | |
307 | mutex_unlock(®istration_lock); | |
308 | } else { | |
309 | struct parport *port; | |
310 | ||
311 | drv->devmodel = false; | |
312 | ||
e962cd9c SM |
313 | if (list_empty(&portlist)) |
314 | get_lowlevel_driver(); | |
6fa45a22 SM |
315 | mutex_lock(®istration_lock); |
316 | list_for_each_entry(port, &portlist, list) | |
317 | drv->attach(port); | |
318 | list_add(&drv->list, &drivers); | |
319 | mutex_unlock(®istration_lock); | |
320 | } | |
321 | ||
322 | return 0; | |
323 | } | |
324 | EXPORT_SYMBOL(__parport_register_driver); | |
325 | ||
326 | static int port_detach(struct device *dev, void *_drv) | |
327 | { | |
328 | struct parport_driver *drv = _drv; | |
329 | ||
330 | if (is_parport(dev) && drv->detach) | |
331 | drv->detach(to_parport_dev(dev)); | |
1da177e4 LT |
332 | |
333 | return 0; | |
334 | } | |
335 | ||
336 | /** | |
337 | * parport_unregister_driver - deregister a parallel port device driver | |
338 | * @drv: structure describing the driver that was given to | |
339 | * parport_register_driver() | |
340 | * | |
341 | * This should be called by a parallel port device driver that | |
342 | * has registered itself using parport_register_driver() when it | |
343 | * is about to be unloaded. | |
344 | * | |
345 | * When it returns, the driver's attach() routine will no longer | |
346 | * be called, and for each port that attach() was called for, the | |
347 | * detach() routine will have been called. | |
348 | * | |
349 | * All the driver's attach() and detach() calls are guaranteed to have | |
350 | * finished by the time this function returns. | |
351 | **/ | |
352 | ||
e732b93c | 353 | void parport_unregister_driver(struct parport_driver *drv) |
1da177e4 LT |
354 | { |
355 | struct parport *port; | |
356 | ||
14cc3e2b | 357 | mutex_lock(®istration_lock); |
6fa45a22 SM |
358 | if (drv->devmodel) { |
359 | bus_for_each_dev(&parport_bus_type, NULL, drv, port_detach); | |
360 | driver_unregister(&drv->driver); | |
361 | } else { | |
362 | list_del_init(&drv->list); | |
363 | list_for_each_entry(port, &portlist, list) | |
364 | drv->detach(port); | |
365 | } | |
14cc3e2b | 366 | mutex_unlock(®istration_lock); |
1da177e4 | 367 | } |
27c6db26 | 368 | EXPORT_SYMBOL(parport_unregister_driver); |
1da177e4 | 369 | |
6fa45a22 | 370 | static void free_port(struct device *dev) |
1da177e4 LT |
371 | { |
372 | int d; | |
6fa45a22 SM |
373 | struct parport *port = to_parport_dev(dev); |
374 | ||
1da177e4 LT |
375 | spin_lock(&full_list_lock); |
376 | list_del(&port->full_list); | |
377 | spin_unlock(&full_list_lock); | |
378 | for (d = 0; d < 5; d++) { | |
6044ec88 JJ |
379 | kfree(port->probe_info[d].class_name); |
380 | kfree(port->probe_info[d].mfr); | |
381 | kfree(port->probe_info[d].model); | |
382 | kfree(port->probe_info[d].cmdset); | |
383 | kfree(port->probe_info[d].description); | |
1da177e4 LT |
384 | } |
385 | ||
386 | kfree(port->name); | |
387 | kfree(port); | |
388 | } | |
389 | ||
390 | /** | |
391 | * parport_get_port - increment a port's reference count | |
392 | * @port: the port | |
393 | * | |
7d469722 | 394 | * This ensures that a struct parport pointer remains valid |
1da177e4 LT |
395 | * until the matching parport_put_port() call. |
396 | **/ | |
397 | ||
e732b93c | 398 | struct parport *parport_get_port(struct parport *port) |
1da177e4 | 399 | { |
6fa45a22 SM |
400 | struct device *dev = get_device(&port->bus_dev); |
401 | ||
402 | return to_parport_dev(dev); | |
403 | } | |
27c6db26 | 404 | EXPORT_SYMBOL(parport_get_port); |
6fa45a22 SM |
405 | |
406 | void parport_del_port(struct parport *port) | |
407 | { | |
408 | device_unregister(&port->bus_dev); | |
1da177e4 | 409 | } |
6fa45a22 | 410 | EXPORT_SYMBOL(parport_del_port); |
1da177e4 LT |
411 | |
412 | /** | |
413 | * parport_put_port - decrement a port's reference count | |
414 | * @port: the port | |
415 | * | |
416 | * This should be called once for each call to parport_get_port(), | |
6fa45a22 SM |
417 | * once the port is no longer needed. When the reference count reaches |
418 | * zero (port is no longer used), free_port is called. | |
1da177e4 LT |
419 | **/ |
420 | ||
e732b93c | 421 | void parport_put_port(struct parport *port) |
1da177e4 | 422 | { |
6fa45a22 | 423 | put_device(&port->bus_dev); |
1da177e4 | 424 | } |
27c6db26 | 425 | EXPORT_SYMBOL(parport_put_port); |
1da177e4 LT |
426 | |
427 | /** | |
428 | * parport_register_port - register a parallel port | |
429 | * @base: base I/O address | |
430 | * @irq: IRQ line | |
431 | * @dma: DMA channel | |
432 | * @ops: pointer to the port driver's port operations structure | |
433 | * | |
434 | * When a parallel port (lowlevel) driver finds a port that | |
435 | * should be made available to parallel port device drivers, it | |
436 | * should call parport_register_port(). The @base, @irq, and | |
437 | * @dma parameters are for the convenience of port drivers, and | |
438 | * for ports where they aren't meaningful needn't be set to | |
439 | * anything special. They can be altered afterwards by adjusting | |
440 | * the relevant members of the parport structure that is returned | |
441 | * and represents the port. They should not be tampered with | |
442 | * after calling parport_announce_port, however. | |
443 | * | |
444 | * If there are parallel port device drivers in the system that | |
445 | * have registered themselves using parport_register_driver(), | |
446 | * they are not told about the port at this time; that is done by | |
447 | * parport_announce_port(). | |
448 | * | |
449 | * The @ops structure is allocated by the caller, and must not be | |
450 | * deallocated before calling parport_remove_port(). | |
451 | * | |
452 | * If there is no memory to allocate a new parport structure, | |
453 | * this function will return %NULL. | |
454 | **/ | |
455 | ||
456 | struct parport *parport_register_port(unsigned long base, int irq, int dma, | |
457 | struct parport_operations *ops) | |
458 | { | |
459 | struct list_head *l; | |
460 | struct parport *tmp; | |
461 | int num; | |
462 | int device; | |
463 | char *name; | |
6fa45a22 | 464 | int ret; |
1da177e4 | 465 | |
c32df4e1 | 466 | tmp = kzalloc(sizeof(struct parport), GFP_KERNEL); |
47ec57ec | 467 | if (!tmp) |
1da177e4 | 468 | return NULL; |
1da177e4 LT |
469 | |
470 | /* Init our structure */ | |
1da177e4 LT |
471 | tmp->base = base; |
472 | tmp->irq = irq; | |
473 | tmp->dma = dma; | |
474 | tmp->muxport = tmp->daisy = tmp->muxsel = -1; | |
475 | tmp->modes = 0; | |
b075e6f0 | 476 | INIT_LIST_HEAD(&tmp->list); |
1da177e4 LT |
477 | tmp->devices = tmp->cad = NULL; |
478 | tmp->flags = 0; | |
479 | tmp->ops = ops; | |
480 | tmp->physport = tmp; | |
e732b93c | 481 | memset(tmp->probe_info, 0, 5 * sizeof(struct parport_device_info)); |
1da177e4 LT |
482 | rwlock_init(&tmp->cad_lock); |
483 | spin_lock_init(&tmp->waitlist_lock); | |
484 | spin_lock_init(&tmp->pardevice_lock); | |
485 | tmp->ieee1284.mode = IEEE1284_MODE_COMPAT; | |
486 | tmp->ieee1284.phase = IEEE1284_PH_FWD_IDLE; | |
a529f150 | 487 | sema_init(&tmp->ieee1284.irq, 0); |
1da177e4 | 488 | tmp->spintime = parport_default_spintime; |
e732b93c | 489 | atomic_set(&tmp->ref_count, 1); |
1da177e4 LT |
490 | INIT_LIST_HEAD(&tmp->full_list); |
491 | ||
492 | name = kmalloc(15, GFP_KERNEL); | |
493 | if (!name) { | |
1da177e4 LT |
494 | kfree(tmp); |
495 | return NULL; | |
496 | } | |
497 | /* Search for the lowest free parport number. */ | |
498 | ||
499 | spin_lock(&full_list_lock); | |
500 | for (l = all_ports.next, num = 0; l != &all_ports; l = l->next, num++) { | |
501 | struct parport *p = list_entry(l, struct parport, full_list); | |
502 | if (p->number != num) | |
503 | break; | |
504 | } | |
505 | tmp->portnum = tmp->number = num; | |
506 | list_add_tail(&tmp->full_list, l); | |
507 | spin_unlock(&full_list_lock); | |
508 | ||
509 | /* | |
510 | * Now that the portnum is known finish doing the Init. | |
511 | */ | |
512 | sprintf(name, "parport%d", tmp->portnum = tmp->number); | |
513 | tmp->name = name; | |
6fa45a22 SM |
514 | tmp->bus_dev.bus = &parport_bus_type; |
515 | tmp->bus_dev.release = free_port; | |
516 | dev_set_name(&tmp->bus_dev, name); | |
517 | tmp->bus_dev.type = &parport_device_type; | |
1da177e4 LT |
518 | |
519 | for (device = 0; device < 5; device++) | |
520 | /* assume the worst */ | |
521 | tmp->probe_info[device].class = PARPORT_CLASS_LEGACY; | |
522 | ||
523 | tmp->waithead = tmp->waittail = NULL; | |
524 | ||
6fa45a22 SM |
525 | ret = device_register(&tmp->bus_dev); |
526 | if (ret) { | |
527 | put_device(&tmp->bus_dev); | |
528 | return NULL; | |
529 | } | |
530 | ||
1da177e4 LT |
531 | return tmp; |
532 | } | |
27c6db26 | 533 | EXPORT_SYMBOL(parport_register_port); |
1da177e4 LT |
534 | |
535 | /** | |
536 | * parport_announce_port - tell device drivers about a parallel port | |
537 | * @port: parallel port to announce | |
538 | * | |
539 | * After a port driver has registered a parallel port with | |
540 | * parport_register_port, and performed any necessary | |
541 | * initialisation or adjustments, it should call | |
542 | * parport_announce_port() in order to notify all device drivers | |
543 | * that have called parport_register_driver(). Their attach() | |
544 | * functions will be called, with @port as the parameter. | |
545 | **/ | |
546 | ||
e732b93c | 547 | void parport_announce_port(struct parport *port) |
1da177e4 LT |
548 | { |
549 | int i; | |
550 | ||
551 | #ifdef CONFIG_PARPORT_1284 | |
552 | /* Analyse the IEEE1284.3 topology of the port. */ | |
553 | parport_daisy_init(port); | |
554 | #endif | |
555 | ||
c15a3837 | 556 | if (!port->dev) |
a162188f SM |
557 | printk(KERN_WARNING "%s: fix this legacy no-device port driver!\n", |
558 | port->name); | |
c15a3837 | 559 | |
1da177e4 | 560 | parport_proc_register(port); |
14cc3e2b | 561 | mutex_lock(®istration_lock); |
1da177e4 LT |
562 | spin_lock_irq(&parportlist_lock); |
563 | list_add_tail(&port->list, &portlist); | |
564 | for (i = 1; i < 3; i++) { | |
565 | struct parport *slave = port->slaves[i-1]; | |
566 | if (slave) | |
567 | list_add_tail(&slave->list, &portlist); | |
568 | } | |
569 | spin_unlock_irq(&parportlist_lock); | |
570 | ||
571 | /* Let drivers know that new port(s) has arrived. */ | |
e732b93c | 572 | attach_driver_chain(port); |
1da177e4 LT |
573 | for (i = 1; i < 3; i++) { |
574 | struct parport *slave = port->slaves[i-1]; | |
575 | if (slave) | |
576 | attach_driver_chain(slave); | |
577 | } | |
14cc3e2b | 578 | mutex_unlock(®istration_lock); |
1da177e4 | 579 | } |
27c6db26 | 580 | EXPORT_SYMBOL(parport_announce_port); |
1da177e4 LT |
581 | |
582 | /** | |
583 | * parport_remove_port - deregister a parallel port | |
584 | * @port: parallel port to deregister | |
585 | * | |
586 | * When a parallel port driver is forcibly unloaded, or a | |
587 | * parallel port becomes inaccessible, the port driver must call | |
588 | * this function in order to deal with device drivers that still | |
589 | * want to use it. | |
590 | * | |
591 | * The parport structure associated with the port has its | |
592 | * operations structure replaced with one containing 'null' | |
593 | * operations that return errors or just don't do anything. | |
594 | * | |
595 | * Any drivers that have registered themselves using | |
596 | * parport_register_driver() are notified that the port is no | |
597 | * longer accessible by having their detach() routines called | |
598 | * with @port as the parameter. | |
599 | **/ | |
600 | ||
601 | void parport_remove_port(struct parport *port) | |
602 | { | |
603 | int i; | |
604 | ||
14cc3e2b | 605 | mutex_lock(®istration_lock); |
1da177e4 LT |
606 | |
607 | /* Spread the word. */ | |
e732b93c | 608 | detach_driver_chain(port); |
1da177e4 LT |
609 | |
610 | #ifdef CONFIG_PARPORT_1284 | |
611 | /* Forget the IEEE1284.3 topology of the port. */ | |
612 | parport_daisy_fini(port); | |
613 | for (i = 1; i < 3; i++) { | |
614 | struct parport *slave = port->slaves[i-1]; | |
615 | if (!slave) | |
616 | continue; | |
617 | detach_driver_chain(slave); | |
618 | parport_daisy_fini(slave); | |
619 | } | |
620 | #endif | |
621 | ||
622 | port->ops = &dead_ops; | |
623 | spin_lock(&parportlist_lock); | |
624 | list_del_init(&port->list); | |
625 | for (i = 1; i < 3; i++) { | |
626 | struct parport *slave = port->slaves[i-1]; | |
627 | if (slave) | |
628 | list_del_init(&slave->list); | |
629 | } | |
630 | spin_unlock(&parportlist_lock); | |
631 | ||
14cc3e2b | 632 | mutex_unlock(®istration_lock); |
1da177e4 LT |
633 | |
634 | parport_proc_unregister(port); | |
635 | ||
636 | for (i = 1; i < 3; i++) { | |
637 | struct parport *slave = port->slaves[i-1]; | |
638 | if (slave) | |
639 | parport_put_port(slave); | |
640 | } | |
641 | } | |
27c6db26 | 642 | EXPORT_SYMBOL(parport_remove_port); |
1da177e4 LT |
643 | |
644 | /** | |
645 | * parport_register_device - register a device on a parallel port | |
646 | * @port: port to which the device is attached | |
647 | * @name: a name to refer to the device | |
648 | * @pf: preemption callback | |
649 | * @kf: kick callback (wake-up) | |
650 | * @irq_func: interrupt handler | |
651 | * @flags: registration flags | |
652 | * @handle: data for callback functions | |
653 | * | |
654 | * This function, called by parallel port device drivers, | |
655 | * declares that a device is connected to a port, and tells the | |
656 | * system all it needs to know. | |
657 | * | |
658 | * The @name is allocated by the caller and must not be | |
659 | * deallocated until the caller calls @parport_unregister_device | |
660 | * for that device. | |
661 | * | |
662 | * The preemption callback function, @pf, is called when this | |
663 | * device driver has claimed access to the port but another | |
664 | * device driver wants to use it. It is given @handle as its | |
665 | * parameter, and should return zero if it is willing for the | |
666 | * system to release the port to another driver on its behalf. | |
667 | * If it wants to keep control of the port it should return | |
668 | * non-zero, and no action will be taken. It is good manners for | |
669 | * the driver to try to release the port at the earliest | |
670 | * opportunity after its preemption callback rejects a preemption | |
671 | * attempt. Note that if a preemption callback is happy for | |
672 | * preemption to go ahead, there is no need to release the port; | |
673 | * it is done automatically. This function may not block, as it | |
674 | * may be called from interrupt context. If the device driver | |
675 | * does not support preemption, @pf can be %NULL. | |
676 | * | |
677 | * The wake-up ("kick") callback function, @kf, is called when | |
678 | * the port is available to be claimed for exclusive access; that | |
679 | * is, parport_claim() is guaranteed to succeed when called from | |
680 | * inside the wake-up callback function. If the driver wants to | |
681 | * claim the port it should do so; otherwise, it need not take | |
682 | * any action. This function may not block, as it may be called | |
683 | * from interrupt context. If the device driver does not want to | |
684 | * be explicitly invited to claim the port in this way, @kf can | |
685 | * be %NULL. | |
686 | * | |
687 | * The interrupt handler, @irq_func, is called when an interrupt | |
688 | * arrives from the parallel port. Note that if a device driver | |
689 | * wants to use interrupts it should use parport_enable_irq(), | |
690 | * and can also check the irq member of the parport structure | |
691 | * representing the port. | |
692 | * | |
693 | * The parallel port (lowlevel) driver is the one that has called | |
694 | * request_irq() and whose interrupt handler is called first. | |
695 | * This handler does whatever needs to be done to the hardware to | |
696 | * acknowledge the interrupt (for PC-style ports there is nothing | |
697 | * special to be done). It then tells the IEEE 1284 code about | |
698 | * the interrupt, which may involve reacting to an IEEE 1284 | |
699 | * event depending on the current IEEE 1284 phase. After this, | |
700 | * it calls @irq_func. Needless to say, @irq_func will be called | |
701 | * from interrupt context, and may not block. | |
702 | * | |
703 | * The %PARPORT_DEV_EXCL flag is for preventing port sharing, and | |
704 | * so should only be used when sharing the port with other device | |
705 | * drivers is impossible and would lead to incorrect behaviour. | |
706 | * Use it sparingly! Normally, @flags will be zero. | |
707 | * | |
708 | * This function returns a pointer to a structure that represents | |
709 | * the device on the port, or %NULL if there is not enough memory | |
710 | * to allocate space for that structure. | |
711 | **/ | |
712 | ||
713 | struct pardevice * | |
714 | parport_register_device(struct parport *port, const char *name, | |
715 | int (*pf)(void *), void (*kf)(void *), | |
657e24d3 | 716 | void (*irq_func)(void *), |
1da177e4 LT |
717 | int flags, void *handle) |
718 | { | |
719 | struct pardevice *tmp; | |
720 | ||
721 | if (port->physport->flags & PARPORT_FLAG_EXCL) { | |
722 | /* An exclusive device is registered. */ | |
e732b93c | 723 | printk(KERN_DEBUG "%s: no more devices allowed\n", |
1da177e4 LT |
724 | port->name); |
725 | return NULL; | |
726 | } | |
727 | ||
728 | if (flags & PARPORT_DEV_LURK) { | |
729 | if (!pf || !kf) { | |
730 | printk(KERN_INFO "%s: refused to register lurking device (%s) without callbacks\n", port->name, name); | |
731 | return NULL; | |
732 | } | |
733 | } | |
734 | ||
50566ac8 SM |
735 | if (flags & PARPORT_DEV_EXCL) { |
736 | if (port->physport->devices) { | |
737 | /* | |
738 | * If a device is already registered and this new | |
739 | * device wants exclusive access, then no need to | |
740 | * continue as we can not grant exclusive access to | |
741 | * this device. | |
742 | */ | |
743 | pr_err("%s: cannot grant exclusive access for device %s\n", | |
744 | port->name, name); | |
745 | return NULL; | |
746 | } | |
747 | } | |
748 | ||
7b7a0a30 SM |
749 | /* |
750 | * We up our own module reference count, and that of the port | |
751 | * on which a device is to be registered, to ensure that | |
752 | * neither of us gets unloaded while we sleep in (e.g.) | |
753 | * kmalloc. | |
754 | */ | |
13efa75d | 755 | if (!try_module_get(port->ops->owner)) |
1da177e4 | 756 | return NULL; |
657e24d3 | 757 | |
e732b93c | 758 | parport_get_port(port); |
1da177e4 LT |
759 | |
760 | tmp = kmalloc(sizeof(struct pardevice), GFP_KERNEL); | |
b95b9d6c | 761 | if (!tmp) |
1da177e4 | 762 | goto out; |
1da177e4 LT |
763 | |
764 | tmp->state = kmalloc(sizeof(struct parport_state), GFP_KERNEL); | |
b95b9d6c | 765 | if (!tmp->state) |
1da177e4 | 766 | goto out_free_pardevice; |
1da177e4 LT |
767 | |
768 | tmp->name = name; | |
769 | tmp->port = port; | |
770 | tmp->daisy = -1; | |
771 | tmp->preempt = pf; | |
772 | tmp->wakeup = kf; | |
773 | tmp->private = handle; | |
774 | tmp->flags = flags; | |
775 | tmp->irq_func = irq_func; | |
776 | tmp->waiting = 0; | |
777 | tmp->timeout = 5 * HZ; | |
6fa45a22 | 778 | tmp->devmodel = false; |
1da177e4 LT |
779 | |
780 | /* Chain this onto the list */ | |
781 | tmp->prev = NULL; | |
782 | /* | |
783 | * This function must not run from an irq handler so we don' t need | |
784 | * to clear irq on the local CPU. -arca | |
785 | */ | |
786 | spin_lock(&port->physport->pardevice_lock); | |
787 | ||
788 | if (flags & PARPORT_DEV_EXCL) { | |
789 | if (port->physport->devices) { | |
e732b93c SM |
790 | spin_unlock(&port->physport->pardevice_lock); |
791 | printk(KERN_DEBUG | |
a162188f SM |
792 | "%s: cannot grant exclusive access for device %s\n", |
793 | port->name, name); | |
1da177e4 LT |
794 | goto out_free_all; |
795 | } | |
796 | port->flags |= PARPORT_FLAG_EXCL; | |
797 | } | |
798 | ||
799 | tmp->next = port->physport->devices; | |
7b7a0a30 SM |
800 | wmb(); /* |
801 | * Make sure that tmp->next is written before it's | |
802 | * added to the list; see comments marked 'no locking | |
803 | * required' | |
804 | */ | |
1da177e4 LT |
805 | if (port->physport->devices) |
806 | port->physport->devices->prev = tmp; | |
807 | port->physport->devices = tmp; | |
808 | spin_unlock(&port->physport->pardevice_lock); | |
809 | ||
810 | init_waitqueue_head(&tmp->wait_q); | |
811 | tmp->timeslice = parport_default_timeslice; | |
812 | tmp->waitnext = tmp->waitprev = NULL; | |
813 | ||
814 | /* | |
815 | * This has to be run as last thing since init_state may need other | |
816 | * pardevice fields. -arca | |
817 | */ | |
818 | port->ops->init_state(tmp, tmp->state); | |
05ad709d AC |
819 | if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) { |
820 | port->proc_device = tmp; | |
821 | parport_device_proc_register(tmp); | |
822 | } | |
1da177e4 LT |
823 | return tmp; |
824 | ||
825 | out_free_all: | |
6044ec88 | 826 | kfree(tmp->state); |
1da177e4 | 827 | out_free_pardevice: |
6044ec88 | 828 | kfree(tmp); |
1da177e4 | 829 | out: |
e732b93c | 830 | parport_put_port(port); |
1da177e4 LT |
831 | module_put(port->ops->owner); |
832 | ||
833 | return NULL; | |
834 | } | |
27c6db26 | 835 | EXPORT_SYMBOL(parport_register_device); |
1da177e4 | 836 | |
6fa45a22 SM |
837 | static void free_pardevice(struct device *dev) |
838 | { | |
839 | struct pardevice *par_dev = to_pardevice(dev); | |
840 | ||
841 | kfree(par_dev->name); | |
842 | kfree(par_dev); | |
843 | } | |
844 | ||
845 | struct pardevice * | |
846 | parport_register_dev_model(struct parport *port, const char *name, | |
847 | const struct pardev_cb *par_dev_cb, int id) | |
848 | { | |
849 | struct pardevice *par_dev; | |
850 | int ret; | |
851 | char *devname; | |
852 | ||
853 | if (port->physport->flags & PARPORT_FLAG_EXCL) { | |
854 | /* An exclusive device is registered. */ | |
855 | pr_err("%s: no more devices allowed\n", port->name); | |
856 | return NULL; | |
857 | } | |
858 | ||
859 | if (par_dev_cb->flags & PARPORT_DEV_LURK) { | |
860 | if (!par_dev_cb->preempt || !par_dev_cb->wakeup) { | |
861 | pr_info("%s: refused to register lurking device (%s) without callbacks\n", | |
862 | port->name, name); | |
863 | return NULL; | |
864 | } | |
865 | } | |
866 | ||
50566ac8 SM |
867 | if (par_dev_cb->flags & PARPORT_DEV_EXCL) { |
868 | if (port->physport->devices) { | |
869 | /* | |
870 | * If a device is already registered and this new | |
871 | * device wants exclusive access, then no need to | |
872 | * continue as we can not grant exclusive access to | |
873 | * this device. | |
874 | */ | |
875 | pr_err("%s: cannot grant exclusive access for device %s\n", | |
876 | port->name, name); | |
877 | return NULL; | |
878 | } | |
879 | } | |
880 | ||
6fa45a22 SM |
881 | if (!try_module_get(port->ops->owner)) |
882 | return NULL; | |
883 | ||
884 | parport_get_port(port); | |
885 | ||
886 | par_dev = kzalloc(sizeof(*par_dev), GFP_KERNEL); | |
887 | if (!par_dev) | |
888 | goto err_put_port; | |
889 | ||
890 | par_dev->state = kzalloc(sizeof(*par_dev->state), GFP_KERNEL); | |
891 | if (!par_dev->state) | |
892 | goto err_put_par_dev; | |
893 | ||
894 | devname = kstrdup(name, GFP_KERNEL); | |
895 | if (!devname) | |
896 | goto err_free_par_dev; | |
897 | ||
898 | par_dev->name = devname; | |
899 | par_dev->port = port; | |
900 | par_dev->daisy = -1; | |
901 | par_dev->preempt = par_dev_cb->preempt; | |
902 | par_dev->wakeup = par_dev_cb->wakeup; | |
903 | par_dev->private = par_dev_cb->private; | |
904 | par_dev->flags = par_dev_cb->flags; | |
905 | par_dev->irq_func = par_dev_cb->irq_func; | |
906 | par_dev->waiting = 0; | |
907 | par_dev->timeout = 5 * HZ; | |
908 | ||
909 | par_dev->dev.parent = &port->bus_dev; | |
910 | par_dev->dev.bus = &parport_bus_type; | |
911 | ret = dev_set_name(&par_dev->dev, "%s.%d", devname, id); | |
912 | if (ret) | |
913 | goto err_free_devname; | |
914 | par_dev->dev.release = free_pardevice; | |
915 | par_dev->devmodel = true; | |
916 | ret = device_register(&par_dev->dev); | |
68d35c7b | 917 | if (ret) { |
1c7ebeab | 918 | kfree(par_dev->state); |
68d35c7b SM |
919 | put_device(&par_dev->dev); |
920 | goto err_put_port; | |
921 | } | |
6fa45a22 SM |
922 | |
923 | /* Chain this onto the list */ | |
924 | par_dev->prev = NULL; | |
925 | /* | |
926 | * This function must not run from an irq handler so we don' t need | |
927 | * to clear irq on the local CPU. -arca | |
928 | */ | |
929 | spin_lock(&port->physport->pardevice_lock); | |
930 | ||
931 | if (par_dev_cb->flags & PARPORT_DEV_EXCL) { | |
932 | if (port->physport->devices) { | |
933 | spin_unlock(&port->physport->pardevice_lock); | |
934 | pr_debug("%s: cannot grant exclusive access for device %s\n", | |
935 | port->name, name); | |
1c7ebeab | 936 | kfree(par_dev->state); |
cabea695 SM |
937 | device_unregister(&par_dev->dev); |
938 | goto err_put_port; | |
6fa45a22 SM |
939 | } |
940 | port->flags |= PARPORT_FLAG_EXCL; | |
941 | } | |
942 | ||
943 | par_dev->next = port->physport->devices; | |
944 | wmb(); /* | |
945 | * Make sure that tmp->next is written before it's | |
946 | * added to the list; see comments marked 'no locking | |
947 | * required' | |
948 | */ | |
949 | if (port->physport->devices) | |
950 | port->physport->devices->prev = par_dev; | |
951 | port->physport->devices = par_dev; | |
952 | spin_unlock(&port->physport->pardevice_lock); | |
953 | ||
954 | init_waitqueue_head(&par_dev->wait_q); | |
955 | par_dev->timeslice = parport_default_timeslice; | |
956 | par_dev->waitnext = NULL; | |
957 | par_dev->waitprev = NULL; | |
958 | ||
959 | /* | |
960 | * This has to be run as last thing since init_state may need other | |
961 | * pardevice fields. -arca | |
962 | */ | |
963 | port->ops->init_state(par_dev, par_dev->state); | |
03270c6a SM |
964 | if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) { |
965 | port->proc_device = par_dev; | |
966 | parport_device_proc_register(par_dev); | |
967 | } | |
6fa45a22 SM |
968 | |
969 | return par_dev; | |
970 | ||
6fa45a22 SM |
971 | err_free_devname: |
972 | kfree(devname); | |
973 | err_free_par_dev: | |
974 | kfree(par_dev->state); | |
975 | err_put_par_dev: | |
976 | if (!par_dev->devmodel) | |
977 | kfree(par_dev); | |
978 | err_put_port: | |
979 | parport_put_port(port); | |
980 | module_put(port->ops->owner); | |
981 | ||
982 | return NULL; | |
983 | } | |
984 | EXPORT_SYMBOL(parport_register_dev_model); | |
985 | ||
1da177e4 LT |
986 | /** |
987 | * parport_unregister_device - deregister a device on a parallel port | |
988 | * @dev: pointer to structure representing device | |
989 | * | |
990 | * This undoes the effect of parport_register_device(). | |
991 | **/ | |
992 | ||
993 | void parport_unregister_device(struct pardevice *dev) | |
994 | { | |
995 | struct parport *port; | |
996 | ||
997 | #ifdef PARPORT_PARANOID | |
b95b9d6c | 998 | if (!dev) { |
1da177e4 LT |
999 | printk(KERN_ERR "parport_unregister_device: passed NULL\n"); |
1000 | return; | |
1001 | } | |
1002 | #endif | |
1003 | ||
1da177e4 LT |
1004 | port = dev->port->physport; |
1005 | ||
05ad709d AC |
1006 | if (port->proc_device == dev) { |
1007 | port->proc_device = NULL; | |
1008 | clear_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags); | |
1009 | parport_device_proc_unregister(dev); | |
1010 | } | |
1011 | ||
1da177e4 LT |
1012 | if (port->cad == dev) { |
1013 | printk(KERN_DEBUG "%s: %s forgot to release port\n", | |
1014 | port->name, dev->name); | |
e732b93c | 1015 | parport_release(dev); |
1da177e4 LT |
1016 | } |
1017 | ||
1018 | spin_lock(&port->pardevice_lock); | |
1019 | if (dev->next) | |
1020 | dev->next->prev = dev->prev; | |
1021 | if (dev->prev) | |
1022 | dev->prev->next = dev->next; | |
1023 | else | |
1024 | port->devices = dev->next; | |
1025 | ||
1026 | if (dev->flags & PARPORT_DEV_EXCL) | |
1027 | port->flags &= ~PARPORT_FLAG_EXCL; | |
1028 | ||
1029 | spin_unlock(&port->pardevice_lock); | |
1030 | ||
7b7a0a30 SM |
1031 | /* |
1032 | * Make sure we haven't left any pointers around in the wait | |
1033 | * list. | |
1034 | */ | |
cbeb4b7a | 1035 | spin_lock_irq(&port->waitlist_lock); |
1da177e4 LT |
1036 | if (dev->waitprev || dev->waitnext || port->waithead == dev) { |
1037 | if (dev->waitprev) | |
1038 | dev->waitprev->waitnext = dev->waitnext; | |
1039 | else | |
1040 | port->waithead = dev->waitnext; | |
1041 | if (dev->waitnext) | |
1042 | dev->waitnext->waitprev = dev->waitprev; | |
1043 | else | |
1044 | port->waittail = dev->waitprev; | |
1045 | } | |
cbeb4b7a | 1046 | spin_unlock_irq(&port->waitlist_lock); |
1da177e4 LT |
1047 | |
1048 | kfree(dev->state); | |
6fa45a22 SM |
1049 | if (dev->devmodel) |
1050 | device_unregister(&dev->dev); | |
1051 | else | |
1052 | kfree(dev); | |
1da177e4 LT |
1053 | |
1054 | module_put(port->ops->owner); | |
e732b93c | 1055 | parport_put_port(port); |
1da177e4 | 1056 | } |
27c6db26 | 1057 | EXPORT_SYMBOL(parport_unregister_device); |
1da177e4 LT |
1058 | |
1059 | /** | |
1060 | * parport_find_number - find a parallel port by number | |
1061 | * @number: parallel port number | |
1062 | * | |
1063 | * This returns the parallel port with the specified number, or | |
1064 | * %NULL if there is none. | |
1065 | * | |
1066 | * There is an implicit parport_get_port() done already; to throw | |
1067 | * away the reference to the port that parport_find_number() | |
1068 | * gives you, use parport_put_port(). | |
1069 | */ | |
1070 | ||
e732b93c | 1071 | struct parport *parport_find_number(int number) |
1da177e4 LT |
1072 | { |
1073 | struct parport *port, *result = NULL; | |
1074 | ||
1075 | if (list_empty(&portlist)) | |
e732b93c | 1076 | get_lowlevel_driver(); |
1da177e4 | 1077 | |
e732b93c | 1078 | spin_lock(&parportlist_lock); |
1da177e4 LT |
1079 | list_for_each_entry(port, &portlist, list) { |
1080 | if (port->number == number) { | |
e732b93c | 1081 | result = parport_get_port(port); |
1da177e4 LT |
1082 | break; |
1083 | } | |
1084 | } | |
e732b93c | 1085 | spin_unlock(&parportlist_lock); |
1da177e4 LT |
1086 | return result; |
1087 | } | |
27c6db26 | 1088 | EXPORT_SYMBOL(parport_find_number); |
1da177e4 LT |
1089 | |
1090 | /** | |
1091 | * parport_find_base - find a parallel port by base address | |
1092 | * @base: base I/O address | |
1093 | * | |
1094 | * This returns the parallel port with the specified base | |
1095 | * address, or %NULL if there is none. | |
1096 | * | |
1097 | * There is an implicit parport_get_port() done already; to throw | |
1098 | * away the reference to the port that parport_find_base() | |
1099 | * gives you, use parport_put_port(). | |
1100 | */ | |
1101 | ||
e732b93c | 1102 | struct parport *parport_find_base(unsigned long base) |
1da177e4 LT |
1103 | { |
1104 | struct parport *port, *result = NULL; | |
1105 | ||
1106 | if (list_empty(&portlist)) | |
e732b93c | 1107 | get_lowlevel_driver(); |
1da177e4 | 1108 | |
e732b93c | 1109 | spin_lock(&parportlist_lock); |
1da177e4 LT |
1110 | list_for_each_entry(port, &portlist, list) { |
1111 | if (port->base == base) { | |
e732b93c | 1112 | result = parport_get_port(port); |
1da177e4 LT |
1113 | break; |
1114 | } | |
1115 | } | |
e732b93c | 1116 | spin_unlock(&parportlist_lock); |
1da177e4 LT |
1117 | return result; |
1118 | } | |
27c6db26 | 1119 | EXPORT_SYMBOL(parport_find_base); |
1da177e4 LT |
1120 | |
1121 | /** | |
1122 | * parport_claim - claim access to a parallel port device | |
1123 | * @dev: pointer to structure representing a device on the port | |
1124 | * | |
1125 | * This function will not block and so can be used from interrupt | |
1126 | * context. If parport_claim() succeeds in claiming access to | |
1127 | * the port it returns zero and the port is available to use. It | |
1128 | * may fail (returning non-zero) if the port is in use by another | |
1129 | * driver and that driver is not willing to relinquish control of | |
1130 | * the port. | |
1131 | **/ | |
1132 | ||
1133 | int parport_claim(struct pardevice *dev) | |
1134 | { | |
1135 | struct pardevice *oldcad; | |
1136 | struct parport *port = dev->port->physport; | |
1137 | unsigned long flags; | |
1138 | ||
1139 | if (port->cad == dev) { | |
1140 | printk(KERN_INFO "%s: %s already owner\n", | |
1141 | dev->port->name,dev->name); | |
1142 | return 0; | |
1143 | } | |
1144 | ||
1145 | /* Preempt any current device */ | |
e732b93c | 1146 | write_lock_irqsave(&port->cad_lock, flags); |
e0a7f1f0 SM |
1147 | oldcad = port->cad; |
1148 | if (oldcad) { | |
1da177e4 LT |
1149 | if (oldcad->preempt) { |
1150 | if (oldcad->preempt(oldcad->private)) | |
1151 | goto blocked; | |
1152 | port->ops->save_state(port, dev->state); | |
1153 | } else | |
1154 | goto blocked; | |
1155 | ||
1156 | if (port->cad != oldcad) { | |
7b7a0a30 SM |
1157 | /* |
1158 | * I think we'll actually deadlock rather than | |
1159 | * get here, but just in case.. | |
1160 | */ | |
1da177e4 LT |
1161 | printk(KERN_WARNING |
1162 | "%s: %s released port when preempted!\n", | |
1163 | port->name, oldcad->name); | |
1164 | if (port->cad) | |
1165 | goto blocked; | |
1166 | } | |
1167 | } | |
1168 | ||
1169 | /* Can't fail from now on, so mark ourselves as no longer waiting. */ | |
1170 | if (dev->waiting & 1) { | |
1171 | dev->waiting = 0; | |
1172 | ||
1173 | /* Take ourselves out of the wait list again. */ | |
e732b93c | 1174 | spin_lock_irq(&port->waitlist_lock); |
1da177e4 LT |
1175 | if (dev->waitprev) |
1176 | dev->waitprev->waitnext = dev->waitnext; | |
1177 | else | |
1178 | port->waithead = dev->waitnext; | |
1179 | if (dev->waitnext) | |
1180 | dev->waitnext->waitprev = dev->waitprev; | |
1181 | else | |
1182 | port->waittail = dev->waitprev; | |
e732b93c | 1183 | spin_unlock_irq(&port->waitlist_lock); |
1da177e4 LT |
1184 | dev->waitprev = dev->waitnext = NULL; |
1185 | } | |
1186 | ||
1187 | /* Now we do the change of devices */ | |
1188 | port->cad = dev; | |
1189 | ||
1190 | #ifdef CONFIG_PARPORT_1284 | |
1191 | /* If it's a mux port, select it. */ | |
1192 | if (dev->port->muxport >= 0) { | |
1193 | /* FIXME */ | |
1194 | port->muxsel = dev->port->muxport; | |
1195 | } | |
1196 | ||
1197 | /* If it's a daisy chain device, select it. */ | |
1198 | if (dev->daisy >= 0) { | |
1199 | /* This could be lazier. */ | |
e732b93c | 1200 | if (!parport_daisy_select(port, dev->daisy, |
1da177e4 LT |
1201 | IEEE1284_MODE_COMPAT)) |
1202 | port->daisy = dev->daisy; | |
1203 | } | |
1204 | #endif /* IEEE1284.3 support */ | |
1205 | ||
1206 | /* Restore control registers */ | |
1207 | port->ops->restore_state(port, dev->state); | |
1208 | write_unlock_irqrestore(&port->cad_lock, flags); | |
1209 | dev->time = jiffies; | |
1210 | return 0; | |
1211 | ||
1212 | blocked: | |
7b7a0a30 SM |
1213 | /* |
1214 | * If this is the first time we tried to claim the port, register an | |
1215 | * interest. This is only allowed for devices sleeping in | |
1216 | * parport_claim_or_block(), or those with a wakeup function. | |
1217 | */ | |
1da177e4 LT |
1218 | |
1219 | /* The cad_lock is still held for writing here */ | |
1220 | if (dev->waiting & 2 || dev->wakeup) { | |
e732b93c | 1221 | spin_lock(&port->waitlist_lock); |
1da177e4 LT |
1222 | if (test_and_set_bit(0, &dev->waiting) == 0) { |
1223 | /* First add ourselves to the end of the wait list. */ | |
1224 | dev->waitnext = NULL; | |
1225 | dev->waitprev = port->waittail; | |
1226 | if (port->waittail) { | |
1227 | port->waittail->waitnext = dev; | |
1228 | port->waittail = dev; | |
1229 | } else | |
1230 | port->waithead = port->waittail = dev; | |
1231 | } | |
e732b93c | 1232 | spin_unlock(&port->waitlist_lock); |
1da177e4 | 1233 | } |
e732b93c | 1234 | write_unlock_irqrestore(&port->cad_lock, flags); |
1da177e4 LT |
1235 | return -EAGAIN; |
1236 | } | |
27c6db26 | 1237 | EXPORT_SYMBOL(parport_claim); |
1da177e4 LT |
1238 | |
1239 | /** | |
1240 | * parport_claim_or_block - claim access to a parallel port device | |
1241 | * @dev: pointer to structure representing a device on the port | |
1242 | * | |
1243 | * This behaves like parport_claim(), but will block if necessary | |
1244 | * to wait for the port to be free. A return value of 1 | |
1245 | * indicates that it slept; 0 means that it succeeded without | |
1246 | * needing to sleep. A negative error code indicates failure. | |
1247 | **/ | |
1248 | ||
1249 | int parport_claim_or_block(struct pardevice *dev) | |
1250 | { | |
1251 | int r; | |
1252 | ||
7b7a0a30 SM |
1253 | /* |
1254 | * Signal to parport_claim() that we can wait even without a | |
1255 | * wakeup function. | |
1256 | */ | |
1da177e4 LT |
1257 | dev->waiting = 2; |
1258 | ||
1259 | /* Try to claim the port. If this fails, we need to sleep. */ | |
1260 | r = parport_claim(dev); | |
1261 | if (r == -EAGAIN) { | |
1262 | #ifdef PARPORT_DEBUG_SHARING | |
1263 | printk(KERN_DEBUG "%s: parport_claim() returned -EAGAIN\n", dev->name); | |
1264 | #endif | |
1265 | /* | |
1266 | * FIXME!!! Use the proper locking for dev->waiting, | |
1267 | * and make this use the "wait_event_interruptible()" | |
1268 | * interfaces. The cli/sti that used to be here | |
1269 | * did nothing. | |
1270 | * | |
1271 | * See also parport_release() | |
1272 | */ | |
1273 | ||
7b7a0a30 SM |
1274 | /* |
1275 | * If dev->waiting is clear now, an interrupt | |
1276 | * gave us the port and we would deadlock if we slept. | |
1277 | */ | |
1da177e4 | 1278 | if (dev->waiting) { |
76ae0536 AB |
1279 | wait_event_interruptible(dev->wait_q, |
1280 | !dev->waiting); | |
e732b93c | 1281 | if (signal_pending(current)) |
1da177e4 | 1282 | return -EINTR; |
1da177e4 LT |
1283 | r = 1; |
1284 | } else { | |
1285 | r = 0; | |
1286 | #ifdef PARPORT_DEBUG_SHARING | |
1287 | printk(KERN_DEBUG "%s: didn't sleep in parport_claim_or_block()\n", | |
1288 | dev->name); | |
1289 | #endif | |
1290 | } | |
1291 | ||
1292 | #ifdef PARPORT_DEBUG_SHARING | |
1293 | if (dev->port->physport->cad != dev) | |
a162188f SM |
1294 | printk(KERN_DEBUG "%s: exiting parport_claim_or_block but %s owns port!\n", |
1295 | dev->name, dev->port->physport->cad ? | |
1da177e4 LT |
1296 | dev->port->physport->cad->name:"nobody"); |
1297 | #endif | |
1298 | } | |
1299 | dev->waiting = 0; | |
1300 | return r; | |
1301 | } | |
27c6db26 | 1302 | EXPORT_SYMBOL(parport_claim_or_block); |
1da177e4 LT |
1303 | |
1304 | /** | |
1305 | * parport_release - give up access to a parallel port device | |
1306 | * @dev: pointer to structure representing parallel port device | |
1307 | * | |
1308 | * This function cannot fail, but it should not be called without | |
1309 | * the port claimed. Similarly, if the port is already claimed | |
1310 | * you should not try claiming it again. | |
1311 | **/ | |
1312 | ||
1313 | void parport_release(struct pardevice *dev) | |
1314 | { | |
1315 | struct parport *port = dev->port->physport; | |
1316 | struct pardevice *pd; | |
1317 | unsigned long flags; | |
1318 | ||
1319 | /* Make sure that dev is the current device */ | |
1320 | write_lock_irqsave(&port->cad_lock, flags); | |
1321 | if (port->cad != dev) { | |
e732b93c | 1322 | write_unlock_irqrestore(&port->cad_lock, flags); |
a162188f SM |
1323 | printk(KERN_WARNING "%s: %s tried to release parport when not owner\n", |
1324 | port->name, dev->name); | |
1da177e4 LT |
1325 | return; |
1326 | } | |
1327 | ||
1328 | #ifdef CONFIG_PARPORT_1284 | |
1329 | /* If this is on a mux port, deselect it. */ | |
1330 | if (dev->port->muxport >= 0) { | |
1331 | /* FIXME */ | |
1332 | port->muxsel = -1; | |
1333 | } | |
1334 | ||
1335 | /* If this is a daisy device, deselect it. */ | |
1336 | if (dev->daisy >= 0) { | |
e732b93c | 1337 | parport_daisy_deselect_all(port); |
1da177e4 LT |
1338 | port->daisy = -1; |
1339 | } | |
1340 | #endif | |
1341 | ||
1342 | port->cad = NULL; | |
1343 | write_unlock_irqrestore(&port->cad_lock, flags); | |
1344 | ||
1345 | /* Save control registers */ | |
1346 | port->ops->save_state(port, dev->state); | |
1347 | ||
7b7a0a30 SM |
1348 | /* |
1349 | * If anybody is waiting, find out who's been there longest and | |
1350 | * then wake them up. (Note: no locking required) | |
1351 | */ | |
1da177e4 LT |
1352 | /* !!! LOCKING IS NEEDED HERE */ |
1353 | for (pd = port->waithead; pd; pd = pd->waitnext) { | |
1354 | if (pd->waiting & 2) { /* sleeping in claim_or_block */ | |
1355 | parport_claim(pd); | |
1356 | if (waitqueue_active(&pd->wait_q)) | |
1357 | wake_up_interruptible(&pd->wait_q); | |
1358 | return; | |
1359 | } else if (pd->wakeup) { | |
1360 | pd->wakeup(pd->private); | |
1361 | if (dev->port->cad) /* racy but no matter */ | |
1362 | return; | |
1363 | } else { | |
1364 | printk(KERN_ERR "%s: don't know how to wake %s\n", port->name, pd->name); | |
1365 | } | |
1366 | } | |
1367 | ||
7b7a0a30 SM |
1368 | /* |
1369 | * Nobody was waiting, so walk the list to see if anyone is | |
1370 | * interested in being woken up. (Note: no locking required) | |
1371 | */ | |
1da177e4 | 1372 | /* !!! LOCKING IS NEEDED HERE */ |
b95b9d6c | 1373 | for (pd = port->devices; !port->cad && pd; pd = pd->next) { |
1da177e4 LT |
1374 | if (pd->wakeup && pd != dev) |
1375 | pd->wakeup(pd->private); | |
1376 | } | |
1377 | } | |
27c6db26 | 1378 | EXPORT_SYMBOL(parport_release); |
1da177e4 | 1379 | |
3f2e40df JG |
1380 | irqreturn_t parport_irq_handler(int irq, void *dev_id) |
1381 | { | |
1382 | struct parport *port = dev_id; | |
1383 | ||
f230d101 | 1384 | parport_generic_irq(port); |
3f2e40df JG |
1385 | |
1386 | return IRQ_HANDLED; | |
1387 | } | |
3f2e40df | 1388 | EXPORT_SYMBOL(parport_irq_handler); |
1da177e4 LT |
1389 | |
1390 | MODULE_LICENSE("GPL"); |