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 | { | |
1aec4211 SM |
140 | int retval; |
141 | ||
142 | retval = bus_register(&parport_bus_type); | |
143 | if (retval) | |
144 | return retval; | |
145 | daisy_drv_init(); | |
146 | ||
147 | return 0; | |
6fa45a22 SM |
148 | } |
149 | ||
150 | void parport_bus_exit(void) | |
151 | { | |
1aec4211 | 152 | daisy_drv_exit(); |
6fa45a22 SM |
153 | bus_unregister(&parport_bus_type); |
154 | } | |
155 | ||
156 | /* | |
157 | * iterates through all the drivers registered with the bus and sends the port | |
158 | * details to the match_port callback of the driver, so that the driver can | |
e9527365 | 159 | * know about the new port that just registered with the bus and decide if it |
6fa45a22 SM |
160 | * wants to use this new port. |
161 | */ | |
162 | static int driver_check(struct device_driver *dev_drv, void *_port) | |
163 | { | |
164 | struct parport *port = _port; | |
165 | struct parport_driver *drv = to_parport_driver(dev_drv); | |
166 | ||
167 | if (drv->match_port) | |
168 | drv->match_port(port); | |
169 | return 0; | |
170 | } | |
171 | ||
1da177e4 LT |
172 | /* Call attach(port) for each registered driver. */ |
173 | static void attach_driver_chain(struct parport *port) | |
174 | { | |
175 | /* caller has exclusive registration_lock */ | |
176 | struct parport_driver *drv; | |
6fa45a22 | 177 | |
1da177e4 LT |
178 | list_for_each_entry(drv, &drivers, list) |
179 | drv->attach(port); | |
6fa45a22 SM |
180 | |
181 | /* | |
182 | * call the driver_check function of the drivers registered in | |
183 | * new device model | |
184 | */ | |
185 | ||
186 | bus_for_each_drv(&parport_bus_type, NULL, port, driver_check); | |
187 | } | |
188 | ||
189 | static int driver_detach(struct device_driver *_drv, void *_port) | |
190 | { | |
191 | struct parport *port = _port; | |
192 | struct parport_driver *drv = to_parport_driver(_drv); | |
193 | ||
194 | if (drv->detach) | |
195 | drv->detach(port); | |
196 | return 0; | |
1da177e4 LT |
197 | } |
198 | ||
199 | /* Call detach(port) for each registered driver. */ | |
200 | static void detach_driver_chain(struct parport *port) | |
201 | { | |
202 | struct parport_driver *drv; | |
203 | /* caller has exclusive registration_lock */ | |
204 | list_for_each_entry(drv, &drivers, list) | |
e732b93c | 205 | drv->detach(port); |
6fa45a22 SM |
206 | |
207 | /* | |
208 | * call the detach function of the drivers registered in | |
209 | * new device model | |
210 | */ | |
211 | ||
212 | bus_for_each_drv(&parport_bus_type, NULL, port, driver_detach); | |
1da177e4 LT |
213 | } |
214 | ||
215 | /* Ask kmod for some lowlevel drivers. */ | |
e732b93c | 216 | static void get_lowlevel_driver(void) |
1da177e4 | 217 | { |
7b7a0a30 SM |
218 | /* |
219 | * There is no actual module called this: you should set | |
220 | * up an alias for modutils. | |
221 | */ | |
e732b93c | 222 | request_module("parport_lowlevel"); |
1da177e4 LT |
223 | } |
224 | ||
6fa45a22 SM |
225 | /* |
226 | * iterates through all the devices connected to the bus and sends the device | |
227 | * details to the match_port callback of the driver, so that the driver can | |
228 | * know what are all the ports that are connected to the bus and choose the | |
229 | * port to which it wants to register its device. | |
230 | */ | |
231 | static int port_check(struct device *dev, void *dev_drv) | |
232 | { | |
233 | struct parport_driver *drv = dev_drv; | |
234 | ||
235 | /* only send ports, do not send other devices connected to bus */ | |
236 | if (is_parport(dev)) | |
237 | drv->match_port(to_parport_dev(dev)); | |
238 | return 0; | |
239 | } | |
240 | ||
1da177e4 LT |
241 | /** |
242 | * parport_register_driver - register a parallel port device driver | |
243 | * @drv: structure describing the driver | |
6fa45a22 SM |
244 | * @owner: owner module of drv |
245 | * @mod_name: module name string | |
1da177e4 LT |
246 | * |
247 | * This can be called by a parallel port device driver in order | |
248 | * to receive notifications about ports being found in the | |
249 | * system, as well as ports no longer available. | |
250 | * | |
6fa45a22 SM |
251 | * If devmodel is true then the new device model is used |
252 | * for registration. | |
253 | * | |
1da177e4 LT |
254 | * The @drv structure is allocated by the caller and must not be |
255 | * deallocated until after calling parport_unregister_driver(). | |
256 | * | |
6fa45a22 | 257 | * If using the non device model: |
1da177e4 LT |
258 | * The driver's attach() function may block. The port that |
259 | * attach() is given will be valid for the duration of the | |
260 | * callback, but if the driver wants to take a copy of the | |
261 | * pointer it must call parport_get_port() to do so. Calling | |
262 | * parport_register_device() on that port will do this for you. | |
263 | * | |
264 | * The driver's detach() function may block. The port that | |
265 | * detach() is given will be valid for the duration of the | |
266 | * callback, but if the driver wants to take a copy of the | |
267 | * pointer it must call parport_get_port() to do so. | |
268 | * | |
6fa45a22 SM |
269 | * |
270 | * Returns 0 on success. The non device model will always succeeds. | |
271 | * but the new device model can fail and will return the error code. | |
1da177e4 LT |
272 | **/ |
273 | ||
6fa45a22 SM |
274 | int __parport_register_driver(struct parport_driver *drv, struct module *owner, |
275 | const char *mod_name) | |
1da177e4 | 276 | { |
1da177e4 | 277 | if (list_empty(&portlist)) |
e732b93c | 278 | get_lowlevel_driver(); |
1da177e4 | 279 | |
6fa45a22 SM |
280 | if (drv->devmodel) { |
281 | /* using device model */ | |
282 | int ret; | |
283 | ||
284 | /* initialize common driver fields */ | |
285 | drv->driver.name = drv->name; | |
286 | drv->driver.bus = &parport_bus_type; | |
287 | drv->driver.owner = owner; | |
288 | drv->driver.mod_name = mod_name; | |
289 | ret = driver_register(&drv->driver); | |
290 | if (ret) | |
291 | return ret; | |
292 | ||
293 | mutex_lock(®istration_lock); | |
294 | if (drv->match_port) | |
295 | bus_for_each_dev(&parport_bus_type, NULL, drv, | |
296 | port_check); | |
297 | mutex_unlock(®istration_lock); | |
298 | } else { | |
299 | struct parport *port; | |
300 | ||
301 | drv->devmodel = false; | |
302 | ||
303 | mutex_lock(®istration_lock); | |
304 | list_for_each_entry(port, &portlist, list) | |
305 | drv->attach(port); | |
306 | list_add(&drv->list, &drivers); | |
307 | mutex_unlock(®istration_lock); | |
308 | } | |
309 | ||
310 | return 0; | |
311 | } | |
312 | EXPORT_SYMBOL(__parport_register_driver); | |
313 | ||
314 | static int port_detach(struct device *dev, void *_drv) | |
315 | { | |
316 | struct parport_driver *drv = _drv; | |
317 | ||
318 | if (is_parport(dev) && drv->detach) | |
319 | drv->detach(to_parport_dev(dev)); | |
1da177e4 LT |
320 | |
321 | return 0; | |
322 | } | |
323 | ||
324 | /** | |
325 | * parport_unregister_driver - deregister a parallel port device driver | |
326 | * @drv: structure describing the driver that was given to | |
327 | * parport_register_driver() | |
328 | * | |
329 | * This should be called by a parallel port device driver that | |
330 | * has registered itself using parport_register_driver() when it | |
331 | * is about to be unloaded. | |
332 | * | |
333 | * When it returns, the driver's attach() routine will no longer | |
334 | * be called, and for each port that attach() was called for, the | |
335 | * detach() routine will have been called. | |
336 | * | |
337 | * All the driver's attach() and detach() calls are guaranteed to have | |
338 | * finished by the time this function returns. | |
339 | **/ | |
340 | ||
e732b93c | 341 | void parport_unregister_driver(struct parport_driver *drv) |
1da177e4 LT |
342 | { |
343 | struct parport *port; | |
344 | ||
14cc3e2b | 345 | mutex_lock(®istration_lock); |
6fa45a22 SM |
346 | if (drv->devmodel) { |
347 | bus_for_each_dev(&parport_bus_type, NULL, drv, port_detach); | |
348 | driver_unregister(&drv->driver); | |
349 | } else { | |
350 | list_del_init(&drv->list); | |
351 | list_for_each_entry(port, &portlist, list) | |
352 | drv->detach(port); | |
353 | } | |
14cc3e2b | 354 | mutex_unlock(®istration_lock); |
1da177e4 | 355 | } |
27c6db26 | 356 | EXPORT_SYMBOL(parport_unregister_driver); |
1da177e4 | 357 | |
6fa45a22 | 358 | static void free_port(struct device *dev) |
1da177e4 LT |
359 | { |
360 | int d; | |
6fa45a22 SM |
361 | struct parport *port = to_parport_dev(dev); |
362 | ||
1da177e4 LT |
363 | spin_lock(&full_list_lock); |
364 | list_del(&port->full_list); | |
365 | spin_unlock(&full_list_lock); | |
366 | for (d = 0; d < 5; d++) { | |
6044ec88 JJ |
367 | kfree(port->probe_info[d].class_name); |
368 | kfree(port->probe_info[d].mfr); | |
369 | kfree(port->probe_info[d].model); | |
370 | kfree(port->probe_info[d].cmdset); | |
371 | kfree(port->probe_info[d].description); | |
1da177e4 LT |
372 | } |
373 | ||
374 | kfree(port->name); | |
375 | kfree(port); | |
376 | } | |
377 | ||
378 | /** | |
379 | * parport_get_port - increment a port's reference count | |
380 | * @port: the port | |
381 | * | |
7d469722 | 382 | * This ensures that a struct parport pointer remains valid |
1da177e4 LT |
383 | * until the matching parport_put_port() call. |
384 | **/ | |
385 | ||
e732b93c | 386 | struct parport *parport_get_port(struct parport *port) |
1da177e4 | 387 | { |
6fa45a22 SM |
388 | struct device *dev = get_device(&port->bus_dev); |
389 | ||
390 | return to_parport_dev(dev); | |
391 | } | |
27c6db26 | 392 | EXPORT_SYMBOL(parport_get_port); |
6fa45a22 SM |
393 | |
394 | void parport_del_port(struct parport *port) | |
395 | { | |
396 | device_unregister(&port->bus_dev); | |
1da177e4 | 397 | } |
6fa45a22 | 398 | EXPORT_SYMBOL(parport_del_port); |
1da177e4 LT |
399 | |
400 | /** | |
401 | * parport_put_port - decrement a port's reference count | |
402 | * @port: the port | |
403 | * | |
404 | * This should be called once for each call to parport_get_port(), | |
6fa45a22 SM |
405 | * once the port is no longer needed. When the reference count reaches |
406 | * zero (port is no longer used), free_port is called. | |
1da177e4 LT |
407 | **/ |
408 | ||
e732b93c | 409 | void parport_put_port(struct parport *port) |
1da177e4 | 410 | { |
6fa45a22 | 411 | put_device(&port->bus_dev); |
1da177e4 | 412 | } |
27c6db26 | 413 | EXPORT_SYMBOL(parport_put_port); |
1da177e4 LT |
414 | |
415 | /** | |
416 | * parport_register_port - register a parallel port | |
417 | * @base: base I/O address | |
418 | * @irq: IRQ line | |
419 | * @dma: DMA channel | |
420 | * @ops: pointer to the port driver's port operations structure | |
421 | * | |
422 | * When a parallel port (lowlevel) driver finds a port that | |
423 | * should be made available to parallel port device drivers, it | |
424 | * should call parport_register_port(). The @base, @irq, and | |
425 | * @dma parameters are for the convenience of port drivers, and | |
426 | * for ports where they aren't meaningful needn't be set to | |
427 | * anything special. They can be altered afterwards by adjusting | |
428 | * the relevant members of the parport structure that is returned | |
429 | * and represents the port. They should not be tampered with | |
430 | * after calling parport_announce_port, however. | |
431 | * | |
432 | * If there are parallel port device drivers in the system that | |
433 | * have registered themselves using parport_register_driver(), | |
434 | * they are not told about the port at this time; that is done by | |
435 | * parport_announce_port(). | |
436 | * | |
437 | * The @ops structure is allocated by the caller, and must not be | |
438 | * deallocated before calling parport_remove_port(). | |
439 | * | |
440 | * If there is no memory to allocate a new parport structure, | |
441 | * this function will return %NULL. | |
442 | **/ | |
443 | ||
444 | struct parport *parport_register_port(unsigned long base, int irq, int dma, | |
445 | struct parport_operations *ops) | |
446 | { | |
447 | struct list_head *l; | |
448 | struct parport *tmp; | |
449 | int num; | |
450 | int device; | |
451 | char *name; | |
6fa45a22 | 452 | int ret; |
1da177e4 | 453 | |
c32df4e1 | 454 | tmp = kzalloc(sizeof(struct parport), GFP_KERNEL); |
47ec57ec | 455 | if (!tmp) |
1da177e4 | 456 | return NULL; |
1da177e4 LT |
457 | |
458 | /* Init our structure */ | |
1da177e4 LT |
459 | tmp->base = base; |
460 | tmp->irq = irq; | |
461 | tmp->dma = dma; | |
462 | tmp->muxport = tmp->daisy = tmp->muxsel = -1; | |
463 | tmp->modes = 0; | |
b075e6f0 | 464 | INIT_LIST_HEAD(&tmp->list); |
1da177e4 LT |
465 | tmp->devices = tmp->cad = NULL; |
466 | tmp->flags = 0; | |
467 | tmp->ops = ops; | |
468 | tmp->physport = tmp; | |
e732b93c | 469 | memset(tmp->probe_info, 0, 5 * sizeof(struct parport_device_info)); |
1da177e4 LT |
470 | rwlock_init(&tmp->cad_lock); |
471 | spin_lock_init(&tmp->waitlist_lock); | |
472 | spin_lock_init(&tmp->pardevice_lock); | |
473 | tmp->ieee1284.mode = IEEE1284_MODE_COMPAT; | |
474 | tmp->ieee1284.phase = IEEE1284_PH_FWD_IDLE; | |
a529f150 | 475 | sema_init(&tmp->ieee1284.irq, 0); |
1da177e4 | 476 | tmp->spintime = parport_default_spintime; |
e732b93c | 477 | atomic_set(&tmp->ref_count, 1); |
1da177e4 LT |
478 | INIT_LIST_HEAD(&tmp->full_list); |
479 | ||
480 | name = kmalloc(15, GFP_KERNEL); | |
481 | if (!name) { | |
1da177e4 LT |
482 | kfree(tmp); |
483 | return NULL; | |
484 | } | |
485 | /* Search for the lowest free parport number. */ | |
486 | ||
487 | spin_lock(&full_list_lock); | |
488 | for (l = all_ports.next, num = 0; l != &all_ports; l = l->next, num++) { | |
489 | struct parport *p = list_entry(l, struct parport, full_list); | |
490 | if (p->number != num) | |
491 | break; | |
492 | } | |
493 | tmp->portnum = tmp->number = num; | |
494 | list_add_tail(&tmp->full_list, l); | |
495 | spin_unlock(&full_list_lock); | |
496 | ||
497 | /* | |
498 | * Now that the portnum is known finish doing the Init. | |
499 | */ | |
500 | sprintf(name, "parport%d", tmp->portnum = tmp->number); | |
501 | tmp->name = name; | |
6fa45a22 SM |
502 | tmp->bus_dev.bus = &parport_bus_type; |
503 | tmp->bus_dev.release = free_port; | |
504 | dev_set_name(&tmp->bus_dev, name); | |
505 | tmp->bus_dev.type = &parport_device_type; | |
1da177e4 LT |
506 | |
507 | for (device = 0; device < 5; device++) | |
508 | /* assume the worst */ | |
509 | tmp->probe_info[device].class = PARPORT_CLASS_LEGACY; | |
510 | ||
511 | tmp->waithead = tmp->waittail = NULL; | |
512 | ||
6fa45a22 SM |
513 | ret = device_register(&tmp->bus_dev); |
514 | if (ret) { | |
515 | put_device(&tmp->bus_dev); | |
516 | return NULL; | |
517 | } | |
518 | ||
1da177e4 LT |
519 | return tmp; |
520 | } | |
27c6db26 | 521 | EXPORT_SYMBOL(parport_register_port); |
1da177e4 LT |
522 | |
523 | /** | |
524 | * parport_announce_port - tell device drivers about a parallel port | |
525 | * @port: parallel port to announce | |
526 | * | |
527 | * After a port driver has registered a parallel port with | |
528 | * parport_register_port, and performed any necessary | |
529 | * initialisation or adjustments, it should call | |
530 | * parport_announce_port() in order to notify all device drivers | |
531 | * that have called parport_register_driver(). Their attach() | |
532 | * functions will be called, with @port as the parameter. | |
533 | **/ | |
534 | ||
e732b93c | 535 | void parport_announce_port(struct parport *port) |
1da177e4 LT |
536 | { |
537 | int i; | |
538 | ||
539 | #ifdef CONFIG_PARPORT_1284 | |
540 | /* Analyse the IEEE1284.3 topology of the port. */ | |
541 | parport_daisy_init(port); | |
542 | #endif | |
543 | ||
c15a3837 | 544 | if (!port->dev) |
a162188f SM |
545 | printk(KERN_WARNING "%s: fix this legacy no-device port driver!\n", |
546 | port->name); | |
c15a3837 | 547 | |
1da177e4 | 548 | parport_proc_register(port); |
14cc3e2b | 549 | mutex_lock(®istration_lock); |
1da177e4 LT |
550 | spin_lock_irq(&parportlist_lock); |
551 | list_add_tail(&port->list, &portlist); | |
552 | for (i = 1; i < 3; i++) { | |
553 | struct parport *slave = port->slaves[i-1]; | |
554 | if (slave) | |
555 | list_add_tail(&slave->list, &portlist); | |
556 | } | |
557 | spin_unlock_irq(&parportlist_lock); | |
558 | ||
559 | /* Let drivers know that new port(s) has arrived. */ | |
e732b93c | 560 | attach_driver_chain(port); |
1da177e4 LT |
561 | for (i = 1; i < 3; i++) { |
562 | struct parport *slave = port->slaves[i-1]; | |
563 | if (slave) | |
564 | attach_driver_chain(slave); | |
565 | } | |
14cc3e2b | 566 | mutex_unlock(®istration_lock); |
1da177e4 | 567 | } |
27c6db26 | 568 | EXPORT_SYMBOL(parport_announce_port); |
1da177e4 LT |
569 | |
570 | /** | |
571 | * parport_remove_port - deregister a parallel port | |
572 | * @port: parallel port to deregister | |
573 | * | |
574 | * When a parallel port driver is forcibly unloaded, or a | |
575 | * parallel port becomes inaccessible, the port driver must call | |
576 | * this function in order to deal with device drivers that still | |
577 | * want to use it. | |
578 | * | |
579 | * The parport structure associated with the port has its | |
580 | * operations structure replaced with one containing 'null' | |
581 | * operations that return errors or just don't do anything. | |
582 | * | |
583 | * Any drivers that have registered themselves using | |
584 | * parport_register_driver() are notified that the port is no | |
585 | * longer accessible by having their detach() routines called | |
586 | * with @port as the parameter. | |
587 | **/ | |
588 | ||
589 | void parport_remove_port(struct parport *port) | |
590 | { | |
591 | int i; | |
592 | ||
14cc3e2b | 593 | mutex_lock(®istration_lock); |
1da177e4 LT |
594 | |
595 | /* Spread the word. */ | |
e732b93c | 596 | detach_driver_chain(port); |
1da177e4 LT |
597 | |
598 | #ifdef CONFIG_PARPORT_1284 | |
599 | /* Forget the IEEE1284.3 topology of the port. */ | |
600 | parport_daisy_fini(port); | |
601 | for (i = 1; i < 3; i++) { | |
602 | struct parport *slave = port->slaves[i-1]; | |
603 | if (!slave) | |
604 | continue; | |
605 | detach_driver_chain(slave); | |
606 | parport_daisy_fini(slave); | |
607 | } | |
608 | #endif | |
609 | ||
610 | port->ops = &dead_ops; | |
611 | spin_lock(&parportlist_lock); | |
612 | list_del_init(&port->list); | |
613 | for (i = 1; i < 3; i++) { | |
614 | struct parport *slave = port->slaves[i-1]; | |
615 | if (slave) | |
616 | list_del_init(&slave->list); | |
617 | } | |
618 | spin_unlock(&parportlist_lock); | |
619 | ||
14cc3e2b | 620 | mutex_unlock(®istration_lock); |
1da177e4 LT |
621 | |
622 | parport_proc_unregister(port); | |
623 | ||
624 | for (i = 1; i < 3; i++) { | |
625 | struct parport *slave = port->slaves[i-1]; | |
626 | if (slave) | |
627 | parport_put_port(slave); | |
628 | } | |
629 | } | |
27c6db26 | 630 | EXPORT_SYMBOL(parport_remove_port); |
1da177e4 LT |
631 | |
632 | /** | |
633 | * parport_register_device - register a device on a parallel port | |
634 | * @port: port to which the device is attached | |
635 | * @name: a name to refer to the device | |
636 | * @pf: preemption callback | |
637 | * @kf: kick callback (wake-up) | |
638 | * @irq_func: interrupt handler | |
639 | * @flags: registration flags | |
640 | * @handle: data for callback functions | |
641 | * | |
642 | * This function, called by parallel port device drivers, | |
643 | * declares that a device is connected to a port, and tells the | |
644 | * system all it needs to know. | |
645 | * | |
646 | * The @name is allocated by the caller and must not be | |
647 | * deallocated until the caller calls @parport_unregister_device | |
648 | * for that device. | |
649 | * | |
650 | * The preemption callback function, @pf, is called when this | |
651 | * device driver has claimed access to the port but another | |
652 | * device driver wants to use it. It is given @handle as its | |
653 | * parameter, and should return zero if it is willing for the | |
654 | * system to release the port to another driver on its behalf. | |
655 | * If it wants to keep control of the port it should return | |
656 | * non-zero, and no action will be taken. It is good manners for | |
657 | * the driver to try to release the port at the earliest | |
658 | * opportunity after its preemption callback rejects a preemption | |
659 | * attempt. Note that if a preemption callback is happy for | |
660 | * preemption to go ahead, there is no need to release the port; | |
661 | * it is done automatically. This function may not block, as it | |
662 | * may be called from interrupt context. If the device driver | |
663 | * does not support preemption, @pf can be %NULL. | |
664 | * | |
665 | * The wake-up ("kick") callback function, @kf, is called when | |
666 | * the port is available to be claimed for exclusive access; that | |
667 | * is, parport_claim() is guaranteed to succeed when called from | |
668 | * inside the wake-up callback function. If the driver wants to | |
669 | * claim the port it should do so; otherwise, it need not take | |
670 | * any action. This function may not block, as it may be called | |
671 | * from interrupt context. If the device driver does not want to | |
672 | * be explicitly invited to claim the port in this way, @kf can | |
673 | * be %NULL. | |
674 | * | |
675 | * The interrupt handler, @irq_func, is called when an interrupt | |
676 | * arrives from the parallel port. Note that if a device driver | |
677 | * wants to use interrupts it should use parport_enable_irq(), | |
678 | * and can also check the irq member of the parport structure | |
679 | * representing the port. | |
680 | * | |
681 | * The parallel port (lowlevel) driver is the one that has called | |
682 | * request_irq() and whose interrupt handler is called first. | |
683 | * This handler does whatever needs to be done to the hardware to | |
684 | * acknowledge the interrupt (for PC-style ports there is nothing | |
685 | * special to be done). It then tells the IEEE 1284 code about | |
686 | * the interrupt, which may involve reacting to an IEEE 1284 | |
687 | * event depending on the current IEEE 1284 phase. After this, | |
688 | * it calls @irq_func. Needless to say, @irq_func will be called | |
689 | * from interrupt context, and may not block. | |
690 | * | |
691 | * The %PARPORT_DEV_EXCL flag is for preventing port sharing, and | |
692 | * so should only be used when sharing the port with other device | |
693 | * drivers is impossible and would lead to incorrect behaviour. | |
694 | * Use it sparingly! Normally, @flags will be zero. | |
695 | * | |
696 | * This function returns a pointer to a structure that represents | |
697 | * the device on the port, or %NULL if there is not enough memory | |
698 | * to allocate space for that structure. | |
699 | **/ | |
700 | ||
701 | struct pardevice * | |
702 | parport_register_device(struct parport *port, const char *name, | |
703 | int (*pf)(void *), void (*kf)(void *), | |
657e24d3 | 704 | void (*irq_func)(void *), |
1da177e4 LT |
705 | int flags, void *handle) |
706 | { | |
707 | struct pardevice *tmp; | |
708 | ||
709 | if (port->physport->flags & PARPORT_FLAG_EXCL) { | |
710 | /* An exclusive device is registered. */ | |
e732b93c | 711 | printk(KERN_DEBUG "%s: no more devices allowed\n", |
1da177e4 LT |
712 | port->name); |
713 | return NULL; | |
714 | } | |
715 | ||
716 | if (flags & PARPORT_DEV_LURK) { | |
717 | if (!pf || !kf) { | |
718 | printk(KERN_INFO "%s: refused to register lurking device (%s) without callbacks\n", port->name, name); | |
719 | return NULL; | |
720 | } | |
721 | } | |
722 | ||
50566ac8 SM |
723 | if (flags & PARPORT_DEV_EXCL) { |
724 | if (port->physport->devices) { | |
725 | /* | |
726 | * If a device is already registered and this new | |
727 | * device wants exclusive access, then no need to | |
728 | * continue as we can not grant exclusive access to | |
729 | * this device. | |
730 | */ | |
731 | pr_err("%s: cannot grant exclusive access for device %s\n", | |
732 | port->name, name); | |
733 | return NULL; | |
734 | } | |
735 | } | |
736 | ||
7b7a0a30 SM |
737 | /* |
738 | * We up our own module reference count, and that of the port | |
739 | * on which a device is to be registered, to ensure that | |
740 | * neither of us gets unloaded while we sleep in (e.g.) | |
741 | * kmalloc. | |
742 | */ | |
13efa75d | 743 | if (!try_module_get(port->ops->owner)) |
1da177e4 | 744 | return NULL; |
657e24d3 | 745 | |
e732b93c | 746 | parport_get_port(port); |
1da177e4 LT |
747 | |
748 | tmp = kmalloc(sizeof(struct pardevice), GFP_KERNEL); | |
b95b9d6c | 749 | if (!tmp) |
1da177e4 | 750 | goto out; |
1da177e4 LT |
751 | |
752 | tmp->state = kmalloc(sizeof(struct parport_state), GFP_KERNEL); | |
b95b9d6c | 753 | if (!tmp->state) |
1da177e4 | 754 | goto out_free_pardevice; |
1da177e4 LT |
755 | |
756 | tmp->name = name; | |
757 | tmp->port = port; | |
758 | tmp->daisy = -1; | |
759 | tmp->preempt = pf; | |
760 | tmp->wakeup = kf; | |
761 | tmp->private = handle; | |
762 | tmp->flags = flags; | |
763 | tmp->irq_func = irq_func; | |
764 | tmp->waiting = 0; | |
765 | tmp->timeout = 5 * HZ; | |
6fa45a22 | 766 | tmp->devmodel = false; |
1da177e4 LT |
767 | |
768 | /* Chain this onto the list */ | |
769 | tmp->prev = NULL; | |
770 | /* | |
771 | * This function must not run from an irq handler so we don' t need | |
772 | * to clear irq on the local CPU. -arca | |
773 | */ | |
774 | spin_lock(&port->physport->pardevice_lock); | |
775 | ||
776 | if (flags & PARPORT_DEV_EXCL) { | |
777 | if (port->physport->devices) { | |
e732b93c SM |
778 | spin_unlock(&port->physport->pardevice_lock); |
779 | printk(KERN_DEBUG | |
a162188f SM |
780 | "%s: cannot grant exclusive access for device %s\n", |
781 | port->name, name); | |
1da177e4 LT |
782 | goto out_free_all; |
783 | } | |
784 | port->flags |= PARPORT_FLAG_EXCL; | |
785 | } | |
786 | ||
787 | tmp->next = port->physport->devices; | |
7b7a0a30 SM |
788 | wmb(); /* |
789 | * Make sure that tmp->next is written before it's | |
790 | * added to the list; see comments marked 'no locking | |
791 | * required' | |
792 | */ | |
1da177e4 LT |
793 | if (port->physport->devices) |
794 | port->physport->devices->prev = tmp; | |
795 | port->physport->devices = tmp; | |
796 | spin_unlock(&port->physport->pardevice_lock); | |
797 | ||
798 | init_waitqueue_head(&tmp->wait_q); | |
799 | tmp->timeslice = parport_default_timeslice; | |
800 | tmp->waitnext = tmp->waitprev = NULL; | |
801 | ||
802 | /* | |
803 | * This has to be run as last thing since init_state may need other | |
804 | * pardevice fields. -arca | |
805 | */ | |
806 | port->ops->init_state(tmp, tmp->state); | |
05ad709d AC |
807 | if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) { |
808 | port->proc_device = tmp; | |
809 | parport_device_proc_register(tmp); | |
810 | } | |
1da177e4 LT |
811 | return tmp; |
812 | ||
813 | out_free_all: | |
6044ec88 | 814 | kfree(tmp->state); |
1da177e4 | 815 | out_free_pardevice: |
6044ec88 | 816 | kfree(tmp); |
1da177e4 | 817 | out: |
e732b93c | 818 | parport_put_port(port); |
1da177e4 LT |
819 | module_put(port->ops->owner); |
820 | ||
821 | return NULL; | |
822 | } | |
27c6db26 | 823 | EXPORT_SYMBOL(parport_register_device); |
1da177e4 | 824 | |
6fa45a22 SM |
825 | static void free_pardevice(struct device *dev) |
826 | { | |
827 | struct pardevice *par_dev = to_pardevice(dev); | |
828 | ||
829 | kfree(par_dev->name); | |
830 | kfree(par_dev); | |
831 | } | |
832 | ||
833 | struct pardevice * | |
834 | parport_register_dev_model(struct parport *port, const char *name, | |
835 | const struct pardev_cb *par_dev_cb, int id) | |
836 | { | |
837 | struct pardevice *par_dev; | |
838 | int ret; | |
839 | char *devname; | |
840 | ||
841 | if (port->physport->flags & PARPORT_FLAG_EXCL) { | |
842 | /* An exclusive device is registered. */ | |
843 | pr_err("%s: no more devices allowed\n", port->name); | |
844 | return NULL; | |
845 | } | |
846 | ||
847 | if (par_dev_cb->flags & PARPORT_DEV_LURK) { | |
848 | if (!par_dev_cb->preempt || !par_dev_cb->wakeup) { | |
849 | pr_info("%s: refused to register lurking device (%s) without callbacks\n", | |
850 | port->name, name); | |
851 | return NULL; | |
852 | } | |
853 | } | |
854 | ||
50566ac8 SM |
855 | if (par_dev_cb->flags & PARPORT_DEV_EXCL) { |
856 | if (port->physport->devices) { | |
857 | /* | |
858 | * If a device is already registered and this new | |
859 | * device wants exclusive access, then no need to | |
860 | * continue as we can not grant exclusive access to | |
861 | * this device. | |
862 | */ | |
863 | pr_err("%s: cannot grant exclusive access for device %s\n", | |
864 | port->name, name); | |
865 | return NULL; | |
866 | } | |
867 | } | |
868 | ||
6fa45a22 SM |
869 | if (!try_module_get(port->ops->owner)) |
870 | return NULL; | |
871 | ||
872 | parport_get_port(port); | |
873 | ||
874 | par_dev = kzalloc(sizeof(*par_dev), GFP_KERNEL); | |
875 | if (!par_dev) | |
876 | goto err_put_port; | |
877 | ||
878 | par_dev->state = kzalloc(sizeof(*par_dev->state), GFP_KERNEL); | |
879 | if (!par_dev->state) | |
880 | goto err_put_par_dev; | |
881 | ||
882 | devname = kstrdup(name, GFP_KERNEL); | |
883 | if (!devname) | |
884 | goto err_free_par_dev; | |
885 | ||
886 | par_dev->name = devname; | |
887 | par_dev->port = port; | |
888 | par_dev->daisy = -1; | |
889 | par_dev->preempt = par_dev_cb->preempt; | |
890 | par_dev->wakeup = par_dev_cb->wakeup; | |
891 | par_dev->private = par_dev_cb->private; | |
892 | par_dev->flags = par_dev_cb->flags; | |
893 | par_dev->irq_func = par_dev_cb->irq_func; | |
894 | par_dev->waiting = 0; | |
895 | par_dev->timeout = 5 * HZ; | |
896 | ||
897 | par_dev->dev.parent = &port->bus_dev; | |
898 | par_dev->dev.bus = &parport_bus_type; | |
899 | ret = dev_set_name(&par_dev->dev, "%s.%d", devname, id); | |
900 | if (ret) | |
901 | goto err_free_devname; | |
902 | par_dev->dev.release = free_pardevice; | |
903 | par_dev->devmodel = true; | |
904 | ret = device_register(&par_dev->dev); | |
68d35c7b SM |
905 | if (ret) { |
906 | put_device(&par_dev->dev); | |
907 | goto err_put_port; | |
908 | } | |
6fa45a22 SM |
909 | |
910 | /* Chain this onto the list */ | |
911 | par_dev->prev = NULL; | |
912 | /* | |
913 | * This function must not run from an irq handler so we don' t need | |
914 | * to clear irq on the local CPU. -arca | |
915 | */ | |
916 | spin_lock(&port->physport->pardevice_lock); | |
917 | ||
918 | if (par_dev_cb->flags & PARPORT_DEV_EXCL) { | |
919 | if (port->physport->devices) { | |
920 | spin_unlock(&port->physport->pardevice_lock); | |
921 | pr_debug("%s: cannot grant exclusive access for device %s\n", | |
922 | port->name, name); | |
cabea695 SM |
923 | device_unregister(&par_dev->dev); |
924 | goto err_put_port; | |
6fa45a22 SM |
925 | } |
926 | port->flags |= PARPORT_FLAG_EXCL; | |
927 | } | |
928 | ||
929 | par_dev->next = port->physport->devices; | |
930 | wmb(); /* | |
931 | * Make sure that tmp->next is written before it's | |
932 | * added to the list; see comments marked 'no locking | |
933 | * required' | |
934 | */ | |
935 | if (port->physport->devices) | |
936 | port->physport->devices->prev = par_dev; | |
937 | port->physport->devices = par_dev; | |
938 | spin_unlock(&port->physport->pardevice_lock); | |
939 | ||
940 | init_waitqueue_head(&par_dev->wait_q); | |
941 | par_dev->timeslice = parport_default_timeslice; | |
942 | par_dev->waitnext = NULL; | |
943 | par_dev->waitprev = NULL; | |
944 | ||
945 | /* | |
946 | * This has to be run as last thing since init_state may need other | |
947 | * pardevice fields. -arca | |
948 | */ | |
949 | port->ops->init_state(par_dev, par_dev->state); | |
03270c6a SM |
950 | if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) { |
951 | port->proc_device = par_dev; | |
952 | parport_device_proc_register(par_dev); | |
953 | } | |
6fa45a22 SM |
954 | |
955 | return par_dev; | |
956 | ||
6fa45a22 SM |
957 | err_free_devname: |
958 | kfree(devname); | |
959 | err_free_par_dev: | |
960 | kfree(par_dev->state); | |
961 | err_put_par_dev: | |
962 | if (!par_dev->devmodel) | |
963 | kfree(par_dev); | |
964 | err_put_port: | |
965 | parport_put_port(port); | |
966 | module_put(port->ops->owner); | |
967 | ||
968 | return NULL; | |
969 | } | |
970 | EXPORT_SYMBOL(parport_register_dev_model); | |
971 | ||
1da177e4 LT |
972 | /** |
973 | * parport_unregister_device - deregister a device on a parallel port | |
974 | * @dev: pointer to structure representing device | |
975 | * | |
976 | * This undoes the effect of parport_register_device(). | |
977 | **/ | |
978 | ||
979 | void parport_unregister_device(struct pardevice *dev) | |
980 | { | |
981 | struct parport *port; | |
982 | ||
983 | #ifdef PARPORT_PARANOID | |
b95b9d6c | 984 | if (!dev) { |
1da177e4 LT |
985 | printk(KERN_ERR "parport_unregister_device: passed NULL\n"); |
986 | return; | |
987 | } | |
988 | #endif | |
989 | ||
1da177e4 LT |
990 | port = dev->port->physport; |
991 | ||
05ad709d AC |
992 | if (port->proc_device == dev) { |
993 | port->proc_device = NULL; | |
994 | clear_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags); | |
995 | parport_device_proc_unregister(dev); | |
996 | } | |
997 | ||
1da177e4 LT |
998 | if (port->cad == dev) { |
999 | printk(KERN_DEBUG "%s: %s forgot to release port\n", | |
1000 | port->name, dev->name); | |
e732b93c | 1001 | parport_release(dev); |
1da177e4 LT |
1002 | } |
1003 | ||
1004 | spin_lock(&port->pardevice_lock); | |
1005 | if (dev->next) | |
1006 | dev->next->prev = dev->prev; | |
1007 | if (dev->prev) | |
1008 | dev->prev->next = dev->next; | |
1009 | else | |
1010 | port->devices = dev->next; | |
1011 | ||
1012 | if (dev->flags & PARPORT_DEV_EXCL) | |
1013 | port->flags &= ~PARPORT_FLAG_EXCL; | |
1014 | ||
1015 | spin_unlock(&port->pardevice_lock); | |
1016 | ||
7b7a0a30 SM |
1017 | /* |
1018 | * Make sure we haven't left any pointers around in the wait | |
1019 | * list. | |
1020 | */ | |
cbeb4b7a | 1021 | spin_lock_irq(&port->waitlist_lock); |
1da177e4 LT |
1022 | if (dev->waitprev || dev->waitnext || port->waithead == dev) { |
1023 | if (dev->waitprev) | |
1024 | dev->waitprev->waitnext = dev->waitnext; | |
1025 | else | |
1026 | port->waithead = dev->waitnext; | |
1027 | if (dev->waitnext) | |
1028 | dev->waitnext->waitprev = dev->waitprev; | |
1029 | else | |
1030 | port->waittail = dev->waitprev; | |
1031 | } | |
cbeb4b7a | 1032 | spin_unlock_irq(&port->waitlist_lock); |
1da177e4 LT |
1033 | |
1034 | kfree(dev->state); | |
6fa45a22 SM |
1035 | if (dev->devmodel) |
1036 | device_unregister(&dev->dev); | |
1037 | else | |
1038 | kfree(dev); | |
1da177e4 LT |
1039 | |
1040 | module_put(port->ops->owner); | |
e732b93c | 1041 | parport_put_port(port); |
1da177e4 | 1042 | } |
27c6db26 | 1043 | EXPORT_SYMBOL(parport_unregister_device); |
1da177e4 LT |
1044 | |
1045 | /** | |
1046 | * parport_find_number - find a parallel port by number | |
1047 | * @number: parallel port number | |
1048 | * | |
1049 | * This returns the parallel port with the specified number, or | |
1050 | * %NULL if there is none. | |
1051 | * | |
1052 | * There is an implicit parport_get_port() done already; to throw | |
1053 | * away the reference to the port that parport_find_number() | |
1054 | * gives you, use parport_put_port(). | |
1055 | */ | |
1056 | ||
e732b93c | 1057 | struct parport *parport_find_number(int number) |
1da177e4 LT |
1058 | { |
1059 | struct parport *port, *result = NULL; | |
1060 | ||
1061 | if (list_empty(&portlist)) | |
e732b93c | 1062 | get_lowlevel_driver(); |
1da177e4 | 1063 | |
e732b93c | 1064 | spin_lock(&parportlist_lock); |
1da177e4 LT |
1065 | list_for_each_entry(port, &portlist, list) { |
1066 | if (port->number == number) { | |
e732b93c | 1067 | result = parport_get_port(port); |
1da177e4 LT |
1068 | break; |
1069 | } | |
1070 | } | |
e732b93c | 1071 | spin_unlock(&parportlist_lock); |
1da177e4 LT |
1072 | return result; |
1073 | } | |
27c6db26 | 1074 | EXPORT_SYMBOL(parport_find_number); |
1da177e4 LT |
1075 | |
1076 | /** | |
1077 | * parport_find_base - find a parallel port by base address | |
1078 | * @base: base I/O address | |
1079 | * | |
1080 | * This returns the parallel port with the specified base | |
1081 | * address, or %NULL if there is none. | |
1082 | * | |
1083 | * There is an implicit parport_get_port() done already; to throw | |
1084 | * away the reference to the port that parport_find_base() | |
1085 | * gives you, use parport_put_port(). | |
1086 | */ | |
1087 | ||
e732b93c | 1088 | struct parport *parport_find_base(unsigned long base) |
1da177e4 LT |
1089 | { |
1090 | struct parport *port, *result = NULL; | |
1091 | ||
1092 | if (list_empty(&portlist)) | |
e732b93c | 1093 | get_lowlevel_driver(); |
1da177e4 | 1094 | |
e732b93c | 1095 | spin_lock(&parportlist_lock); |
1da177e4 LT |
1096 | list_for_each_entry(port, &portlist, list) { |
1097 | if (port->base == base) { | |
e732b93c | 1098 | result = parport_get_port(port); |
1da177e4 LT |
1099 | break; |
1100 | } | |
1101 | } | |
e732b93c | 1102 | spin_unlock(&parportlist_lock); |
1da177e4 LT |
1103 | return result; |
1104 | } | |
27c6db26 | 1105 | EXPORT_SYMBOL(parport_find_base); |
1da177e4 LT |
1106 | |
1107 | /** | |
1108 | * parport_claim - claim access to a parallel port device | |
1109 | * @dev: pointer to structure representing a device on the port | |
1110 | * | |
1111 | * This function will not block and so can be used from interrupt | |
1112 | * context. If parport_claim() succeeds in claiming access to | |
1113 | * the port it returns zero and the port is available to use. It | |
1114 | * may fail (returning non-zero) if the port is in use by another | |
1115 | * driver and that driver is not willing to relinquish control of | |
1116 | * the port. | |
1117 | **/ | |
1118 | ||
1119 | int parport_claim(struct pardevice *dev) | |
1120 | { | |
1121 | struct pardevice *oldcad; | |
1122 | struct parport *port = dev->port->physport; | |
1123 | unsigned long flags; | |
1124 | ||
1125 | if (port->cad == dev) { | |
1126 | printk(KERN_INFO "%s: %s already owner\n", | |
1127 | dev->port->name,dev->name); | |
1128 | return 0; | |
1129 | } | |
1130 | ||
1131 | /* Preempt any current device */ | |
e732b93c | 1132 | write_lock_irqsave(&port->cad_lock, flags); |
e0a7f1f0 SM |
1133 | oldcad = port->cad; |
1134 | if (oldcad) { | |
1da177e4 LT |
1135 | if (oldcad->preempt) { |
1136 | if (oldcad->preempt(oldcad->private)) | |
1137 | goto blocked; | |
1138 | port->ops->save_state(port, dev->state); | |
1139 | } else | |
1140 | goto blocked; | |
1141 | ||
1142 | if (port->cad != oldcad) { | |
7b7a0a30 SM |
1143 | /* |
1144 | * I think we'll actually deadlock rather than | |
1145 | * get here, but just in case.. | |
1146 | */ | |
1da177e4 LT |
1147 | printk(KERN_WARNING |
1148 | "%s: %s released port when preempted!\n", | |
1149 | port->name, oldcad->name); | |
1150 | if (port->cad) | |
1151 | goto blocked; | |
1152 | } | |
1153 | } | |
1154 | ||
1155 | /* Can't fail from now on, so mark ourselves as no longer waiting. */ | |
1156 | if (dev->waiting & 1) { | |
1157 | dev->waiting = 0; | |
1158 | ||
1159 | /* Take ourselves out of the wait list again. */ | |
e732b93c | 1160 | spin_lock_irq(&port->waitlist_lock); |
1da177e4 LT |
1161 | if (dev->waitprev) |
1162 | dev->waitprev->waitnext = dev->waitnext; | |
1163 | else | |
1164 | port->waithead = dev->waitnext; | |
1165 | if (dev->waitnext) | |
1166 | dev->waitnext->waitprev = dev->waitprev; | |
1167 | else | |
1168 | port->waittail = dev->waitprev; | |
e732b93c | 1169 | spin_unlock_irq(&port->waitlist_lock); |
1da177e4 LT |
1170 | dev->waitprev = dev->waitnext = NULL; |
1171 | } | |
1172 | ||
1173 | /* Now we do the change of devices */ | |
1174 | port->cad = dev; | |
1175 | ||
1176 | #ifdef CONFIG_PARPORT_1284 | |
1177 | /* If it's a mux port, select it. */ | |
1178 | if (dev->port->muxport >= 0) { | |
1179 | /* FIXME */ | |
1180 | port->muxsel = dev->port->muxport; | |
1181 | } | |
1182 | ||
1183 | /* If it's a daisy chain device, select it. */ | |
1184 | if (dev->daisy >= 0) { | |
1185 | /* This could be lazier. */ | |
e732b93c | 1186 | if (!parport_daisy_select(port, dev->daisy, |
1da177e4 LT |
1187 | IEEE1284_MODE_COMPAT)) |
1188 | port->daisy = dev->daisy; | |
1189 | } | |
1190 | #endif /* IEEE1284.3 support */ | |
1191 | ||
1192 | /* Restore control registers */ | |
1193 | port->ops->restore_state(port, dev->state); | |
1194 | write_unlock_irqrestore(&port->cad_lock, flags); | |
1195 | dev->time = jiffies; | |
1196 | return 0; | |
1197 | ||
1198 | blocked: | |
7b7a0a30 SM |
1199 | /* |
1200 | * If this is the first time we tried to claim the port, register an | |
1201 | * interest. This is only allowed for devices sleeping in | |
1202 | * parport_claim_or_block(), or those with a wakeup function. | |
1203 | */ | |
1da177e4 LT |
1204 | |
1205 | /* The cad_lock is still held for writing here */ | |
1206 | if (dev->waiting & 2 || dev->wakeup) { | |
e732b93c | 1207 | spin_lock(&port->waitlist_lock); |
1da177e4 LT |
1208 | if (test_and_set_bit(0, &dev->waiting) == 0) { |
1209 | /* First add ourselves to the end of the wait list. */ | |
1210 | dev->waitnext = NULL; | |
1211 | dev->waitprev = port->waittail; | |
1212 | if (port->waittail) { | |
1213 | port->waittail->waitnext = dev; | |
1214 | port->waittail = dev; | |
1215 | } else | |
1216 | port->waithead = port->waittail = dev; | |
1217 | } | |
e732b93c | 1218 | spin_unlock(&port->waitlist_lock); |
1da177e4 | 1219 | } |
e732b93c | 1220 | write_unlock_irqrestore(&port->cad_lock, flags); |
1da177e4 LT |
1221 | return -EAGAIN; |
1222 | } | |
27c6db26 | 1223 | EXPORT_SYMBOL(parport_claim); |
1da177e4 LT |
1224 | |
1225 | /** | |
1226 | * parport_claim_or_block - claim access to a parallel port device | |
1227 | * @dev: pointer to structure representing a device on the port | |
1228 | * | |
1229 | * This behaves like parport_claim(), but will block if necessary | |
1230 | * to wait for the port to be free. A return value of 1 | |
1231 | * indicates that it slept; 0 means that it succeeded without | |
1232 | * needing to sleep. A negative error code indicates failure. | |
1233 | **/ | |
1234 | ||
1235 | int parport_claim_or_block(struct pardevice *dev) | |
1236 | { | |
1237 | int r; | |
1238 | ||
7b7a0a30 SM |
1239 | /* |
1240 | * Signal to parport_claim() that we can wait even without a | |
1241 | * wakeup function. | |
1242 | */ | |
1da177e4 LT |
1243 | dev->waiting = 2; |
1244 | ||
1245 | /* Try to claim the port. If this fails, we need to sleep. */ | |
1246 | r = parport_claim(dev); | |
1247 | if (r == -EAGAIN) { | |
1248 | #ifdef PARPORT_DEBUG_SHARING | |
1249 | printk(KERN_DEBUG "%s: parport_claim() returned -EAGAIN\n", dev->name); | |
1250 | #endif | |
1251 | /* | |
1252 | * FIXME!!! Use the proper locking for dev->waiting, | |
1253 | * and make this use the "wait_event_interruptible()" | |
1254 | * interfaces. The cli/sti that used to be here | |
1255 | * did nothing. | |
1256 | * | |
1257 | * See also parport_release() | |
1258 | */ | |
1259 | ||
7b7a0a30 SM |
1260 | /* |
1261 | * If dev->waiting is clear now, an interrupt | |
1262 | * gave us the port and we would deadlock if we slept. | |
1263 | */ | |
1da177e4 | 1264 | if (dev->waiting) { |
76ae0536 AB |
1265 | wait_event_interruptible(dev->wait_q, |
1266 | !dev->waiting); | |
e732b93c | 1267 | if (signal_pending(current)) |
1da177e4 | 1268 | return -EINTR; |
1da177e4 LT |
1269 | r = 1; |
1270 | } else { | |
1271 | r = 0; | |
1272 | #ifdef PARPORT_DEBUG_SHARING | |
1273 | printk(KERN_DEBUG "%s: didn't sleep in parport_claim_or_block()\n", | |
1274 | dev->name); | |
1275 | #endif | |
1276 | } | |
1277 | ||
1278 | #ifdef PARPORT_DEBUG_SHARING | |
1279 | if (dev->port->physport->cad != dev) | |
a162188f SM |
1280 | printk(KERN_DEBUG "%s: exiting parport_claim_or_block but %s owns port!\n", |
1281 | dev->name, dev->port->physport->cad ? | |
1da177e4 LT |
1282 | dev->port->physport->cad->name:"nobody"); |
1283 | #endif | |
1284 | } | |
1285 | dev->waiting = 0; | |
1286 | return r; | |
1287 | } | |
27c6db26 | 1288 | EXPORT_SYMBOL(parport_claim_or_block); |
1da177e4 LT |
1289 | |
1290 | /** | |
1291 | * parport_release - give up access to a parallel port device | |
1292 | * @dev: pointer to structure representing parallel port device | |
1293 | * | |
1294 | * This function cannot fail, but it should not be called without | |
1295 | * the port claimed. Similarly, if the port is already claimed | |
1296 | * you should not try claiming it again. | |
1297 | **/ | |
1298 | ||
1299 | void parport_release(struct pardevice *dev) | |
1300 | { | |
1301 | struct parport *port = dev->port->physport; | |
1302 | struct pardevice *pd; | |
1303 | unsigned long flags; | |
1304 | ||
1305 | /* Make sure that dev is the current device */ | |
1306 | write_lock_irqsave(&port->cad_lock, flags); | |
1307 | if (port->cad != dev) { | |
e732b93c | 1308 | write_unlock_irqrestore(&port->cad_lock, flags); |
a162188f SM |
1309 | printk(KERN_WARNING "%s: %s tried to release parport when not owner\n", |
1310 | port->name, dev->name); | |
1da177e4 LT |
1311 | return; |
1312 | } | |
1313 | ||
1314 | #ifdef CONFIG_PARPORT_1284 | |
1315 | /* If this is on a mux port, deselect it. */ | |
1316 | if (dev->port->muxport >= 0) { | |
1317 | /* FIXME */ | |
1318 | port->muxsel = -1; | |
1319 | } | |
1320 | ||
1321 | /* If this is a daisy device, deselect it. */ | |
1322 | if (dev->daisy >= 0) { | |
e732b93c | 1323 | parport_daisy_deselect_all(port); |
1da177e4 LT |
1324 | port->daisy = -1; |
1325 | } | |
1326 | #endif | |
1327 | ||
1328 | port->cad = NULL; | |
1329 | write_unlock_irqrestore(&port->cad_lock, flags); | |
1330 | ||
1331 | /* Save control registers */ | |
1332 | port->ops->save_state(port, dev->state); | |
1333 | ||
7b7a0a30 SM |
1334 | /* |
1335 | * If anybody is waiting, find out who's been there longest and | |
1336 | * then wake them up. (Note: no locking required) | |
1337 | */ | |
1da177e4 LT |
1338 | /* !!! LOCKING IS NEEDED HERE */ |
1339 | for (pd = port->waithead; pd; pd = pd->waitnext) { | |
1340 | if (pd->waiting & 2) { /* sleeping in claim_or_block */ | |
1341 | parport_claim(pd); | |
1342 | if (waitqueue_active(&pd->wait_q)) | |
1343 | wake_up_interruptible(&pd->wait_q); | |
1344 | return; | |
1345 | } else if (pd->wakeup) { | |
1346 | pd->wakeup(pd->private); | |
1347 | if (dev->port->cad) /* racy but no matter */ | |
1348 | return; | |
1349 | } else { | |
1350 | printk(KERN_ERR "%s: don't know how to wake %s\n", port->name, pd->name); | |
1351 | } | |
1352 | } | |
1353 | ||
7b7a0a30 SM |
1354 | /* |
1355 | * Nobody was waiting, so walk the list to see if anyone is | |
1356 | * interested in being woken up. (Note: no locking required) | |
1357 | */ | |
1da177e4 | 1358 | /* !!! LOCKING IS NEEDED HERE */ |
b95b9d6c | 1359 | for (pd = port->devices; !port->cad && pd; pd = pd->next) { |
1da177e4 LT |
1360 | if (pd->wakeup && pd != dev) |
1361 | pd->wakeup(pd->private); | |
1362 | } | |
1363 | } | |
27c6db26 | 1364 | EXPORT_SYMBOL(parport_release); |
1da177e4 | 1365 | |
3f2e40df JG |
1366 | irqreturn_t parport_irq_handler(int irq, void *dev_id) |
1367 | { | |
1368 | struct parport *port = dev_id; | |
1369 | ||
f230d101 | 1370 | parport_generic_irq(port); |
3f2e40df JG |
1371 | |
1372 | return IRQ_HANDLED; | |
1373 | } | |
3f2e40df | 1374 | EXPORT_SYMBOL(parport_irq_handler); |
1da177e4 LT |
1375 | |
1376 | MODULE_LICENSE("GPL"); |