blob: 3308427ed9f7a04bb50119882a2130f6e7ee13ed [file] [log] [blame]
Adrian Bunk612de102008-10-15 22:04:33 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * Parallel-port resource manager code.
Sudip Mukherjee657e24d2015-10-28 14:41:31 +05303 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * Authors: David Campbell <campbell@tirian.che.curtin.edu.au>
5 * Tim Waugh <tim@cyberelk.demon.co.uk>
6 * Jose Renau <renau@acm.org>
7 * Philip Blundell <philb@gnu.org>
8 * Andrea Arcangeli
9 *
10 * based on work by Grant Guenther <grant@torque.net>
11 * and Philip Blundell
12 *
13 * Any part of this program may be used in documents licensed under
14 * the GNU Free Documentation License, Version 1.1 or any later version
15 * published by the Free Software Foundation.
16 */
17
18#undef PARPORT_DEBUG_SHARING /* undef for production */
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/module.h>
21#include <linux/string.h>
22#include <linux/threads.h>
23#include <linux/parport.h>
24#include <linux/delay.h>
25#include <linux/errno.h>
26#include <linux/interrupt.h>
27#include <linux/ioport.h>
28#include <linux/kernel.h>
29#include <linux/slab.h>
30#include <linux/sched.h>
31#include <linux/kmod.h>
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +053032#include <linux/device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#include <linux/spinlock.h>
Ingo Molnar14cc3e22006-03-26 01:37:14 -080035#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <asm/irq.h>
37
38#undef PARPORT_PARANOID
39
40#define PARPORT_DEFAULT_TIMESLICE (HZ/5)
41
42unsigned long parport_default_timeslice = PARPORT_DEFAULT_TIMESLICE;
43int parport_default_spintime = DEFAULT_SPIN_TIME;
44
45static LIST_HEAD(portlist);
46static DEFINE_SPINLOCK(parportlist_lock);
47
48/* list of all allocated ports, sorted by ->number */
49static LIST_HEAD(all_ports);
50static DEFINE_SPINLOCK(full_list_lock);
51
52static LIST_HEAD(drivers);
53
Ingo Molnar14cc3e22006-03-26 01:37:14 -080054static DEFINE_MUTEX(registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56/* What you can do to a port that's gone away.. */
Sudip Mukherjeee732b932015-10-28 14:41:39 +053057static void dead_write_lines(struct parport *p, unsigned char b){}
58static unsigned char dead_read_lines(struct parport *p) { return 0; }
59static unsigned char dead_frob_lines(struct parport *p, unsigned char b,
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 unsigned char c) { return 0; }
Sudip Mukherjeee732b932015-10-28 14:41:39 +053061static void dead_onearg(struct parport *p){}
62static void dead_initstate(struct pardevice *d, struct parport_state *s) { }
63static void dead_state(struct parport *p, struct parport_state *s) { }
64static size_t dead_write(struct parport *p, const void *b, size_t l, int f)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065{ return 0; }
Sudip Mukherjeee732b932015-10-28 14:41:39 +053066static size_t dead_read(struct parport *p, void *b, size_t l, int f)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{ return 0; }
68static struct parport_operations dead_ops = {
69 .write_data = dead_write_lines, /* data */
70 .read_data = dead_read_lines,
71
72 .write_control = dead_write_lines, /* control */
73 .read_control = dead_read_lines,
74 .frob_control = dead_frob_lines,
75
76 .read_status = dead_read_lines, /* status */
77
78 .enable_irq = dead_onearg, /* enable_irq */
79 .disable_irq = dead_onearg, /* disable_irq */
80
81 .data_forward = dead_onearg, /* data_forward */
82 .data_reverse = dead_onearg, /* data_reverse */
83
84 .init_state = dead_initstate, /* init_state */
85 .save_state = dead_state,
86 .restore_state = dead_state,
87
88 .epp_write_data = dead_write, /* epp */
89 .epp_read_data = dead_read,
90 .epp_write_addr = dead_write,
91 .epp_read_addr = dead_read,
92
93 .ecp_write_data = dead_write, /* ecp */
94 .ecp_read_data = dead_read,
95 .ecp_write_addr = dead_write,
Sudip Mukherjee657e24d2015-10-28 14:41:31 +053096
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 .compat_write_data = dead_write, /* compat */
98 .nibble_read_data = dead_read, /* nibble */
99 .byte_read_data = dead_read, /* byte */
100
101 .owner = NULL,
102};
103
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530104static struct device_type parport_device_type = {
105 .name = "parport",
106};
107
108static int is_parport(struct device *dev)
109{
110 return dev->type == &parport_device_type;
111}
112
113static int parport_probe(struct device *dev)
114{
115 struct parport_driver *drv;
116
117 if (is_parport(dev))
118 return -ENODEV;
119
120 drv = to_parport_driver(dev->driver);
121 if (!drv->probe) {
122 /* if driver has not defined a custom probe */
123 struct pardevice *par_dev = to_pardevice(dev);
124
125 if (strcmp(par_dev->name, drv->name))
126 return -ENODEV;
127 return 0;
128 }
129 /* if driver defined its own probe */
130 return drv->probe(to_pardevice(dev));
131}
132
133static struct bus_type parport_bus_type = {
134 .name = "parport",
135 .probe = parport_probe,
136};
137
138int parport_bus_init(void)
139{
140 return bus_register(&parport_bus_type);
141}
142
143void parport_bus_exit(void)
144{
145 bus_unregister(&parport_bus_type);
146}
147
148/*
149 * iterates through all the drivers registered with the bus and sends the port
150 * details to the match_port callback of the driver, so that the driver can
Geliang Tange9527362015-10-28 14:41:30 +0530151 * know about the new port that just registered with the bus and decide if it
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530152 * wants to use this new port.
153 */
154static int driver_check(struct device_driver *dev_drv, void *_port)
155{
156 struct parport *port = _port;
157 struct parport_driver *drv = to_parport_driver(dev_drv);
158
159 if (drv->match_port)
160 drv->match_port(port);
161 return 0;
162}
163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164/* Call attach(port) for each registered driver. */
165static void attach_driver_chain(struct parport *port)
166{
167 /* caller has exclusive registration_lock */
168 struct parport_driver *drv;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530169
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 list_for_each_entry(drv, &drivers, list)
171 drv->attach(port);
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530172
173 /*
174 * call the driver_check function of the drivers registered in
175 * new device model
176 */
177
178 bus_for_each_drv(&parport_bus_type, NULL, port, driver_check);
179}
180
181static int driver_detach(struct device_driver *_drv, void *_port)
182{
183 struct parport *port = _port;
184 struct parport_driver *drv = to_parport_driver(_drv);
185
186 if (drv->detach)
187 drv->detach(port);
188 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189}
190
191/* Call detach(port) for each registered driver. */
192static void detach_driver_chain(struct parport *port)
193{
194 struct parport_driver *drv;
195 /* caller has exclusive registration_lock */
196 list_for_each_entry(drv, &drivers, list)
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530197 drv->detach(port);
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530198
199 /*
200 * call the detach function of the drivers registered in
201 * new device model
202 */
203
204 bus_for_each_drv(&parport_bus_type, NULL, port, driver_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205}
206
207/* Ask kmod for some lowlevel drivers. */
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530208static void get_lowlevel_driver(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209{
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +0530210 /*
211 * There is no actual module called this: you should set
212 * up an alias for modutils.
213 */
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530214 request_module("parport_lowlevel");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215}
216
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530217/*
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 */
223static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233/**
234 * parport_register_driver - register a parallel port device driver
235 * @drv: structure describing the driver
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530236 * @owner: owner module of drv
237 * @mod_name: module name string
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 *
239 * This can be called by a parallel port device driver in order
240 * to receive notifications about ports being found in the
241 * system, as well as ports no longer available.
242 *
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530243 * If devmodel is true then the new device model is used
244 * for registration.
245 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 * The @drv structure is allocated by the caller and must not be
247 * deallocated until after calling parport_unregister_driver().
248 *
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530249 * If using the non device model:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 * The driver's attach() function may block. The port that
251 * attach() is given will be valid for the duration of the
252 * callback, but if the driver wants to take a copy of the
253 * pointer it must call parport_get_port() to do so. Calling
254 * parport_register_device() on that port will do this for you.
255 *
256 * The driver's detach() function may block. The port that
257 * detach() is given will be valid for the duration of the
258 * callback, but if the driver wants to take a copy of the
259 * pointer it must call parport_get_port() to do so.
260 *
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530261 *
262 * Returns 0 on success. The non device model will always succeeds.
263 * but the new device model can fail and will return the error code.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 **/
265
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530266int __parport_register_driver(struct parport_driver *drv, struct module *owner,
267 const char *mod_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 if (list_empty(&portlist))
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530270 get_lowlevel_driver();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530272 if (drv->devmodel) {
273 /* using device model */
274 int ret;
275
276 /* initialize common driver fields */
277 drv->driver.name = drv->name;
278 drv->driver.bus = &parport_bus_type;
279 drv->driver.owner = owner;
280 drv->driver.mod_name = mod_name;
281 ret = driver_register(&drv->driver);
282 if (ret)
283 return ret;
284
285 mutex_lock(&registration_lock);
286 if (drv->match_port)
287 bus_for_each_dev(&parport_bus_type, NULL, drv,
288 port_check);
289 mutex_unlock(&registration_lock);
290 } else {
291 struct parport *port;
292
293 drv->devmodel = false;
294
295 mutex_lock(&registration_lock);
296 list_for_each_entry(port, &portlist, list)
297 drv->attach(port);
298 list_add(&drv->list, &drivers);
299 mutex_unlock(&registration_lock);
300 }
301
302 return 0;
303}
304EXPORT_SYMBOL(__parport_register_driver);
305
306static int port_detach(struct device *dev, void *_drv)
307{
308 struct parport_driver *drv = _drv;
309
310 if (is_parport(dev) && drv->detach)
311 drv->detach(to_parport_dev(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
313 return 0;
314}
315
316/**
317 * parport_unregister_driver - deregister a parallel port device driver
318 * @drv: structure describing the driver that was given to
319 * parport_register_driver()
320 *
321 * This should be called by a parallel port device driver that
322 * has registered itself using parport_register_driver() when it
323 * is about to be unloaded.
324 *
325 * When it returns, the driver's attach() routine will no longer
326 * be called, and for each port that attach() was called for, the
327 * detach() routine will have been called.
328 *
329 * All the driver's attach() and detach() calls are guaranteed to have
330 * finished by the time this function returns.
331 **/
332
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530333void parport_unregister_driver(struct parport_driver *drv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334{
335 struct parport *port;
336
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800337 mutex_lock(&registration_lock);
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530338 if (drv->devmodel) {
339 bus_for_each_dev(&parport_bus_type, NULL, drv, port_detach);
340 driver_unregister(&drv->driver);
341 } else {
342 list_del_init(&drv->list);
343 list_for_each_entry(port, &portlist, list)
344 drv->detach(port);
345 }
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800346 mutex_unlock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +0530348EXPORT_SYMBOL(parport_unregister_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530350static void free_port(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351{
352 int d;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530353 struct parport *port = to_parport_dev(dev);
354
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 spin_lock(&full_list_lock);
356 list_del(&port->full_list);
357 spin_unlock(&full_list_lock);
358 for (d = 0; d < 5; d++) {
Jesper Juhl6044ec82005-11-07 01:01:32 -0800359 kfree(port->probe_info[d].class_name);
360 kfree(port->probe_info[d].mfr);
361 kfree(port->probe_info[d].model);
362 kfree(port->probe_info[d].cmdset);
363 kfree(port->probe_info[d].description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 }
365
366 kfree(port->name);
367 kfree(port);
368}
369
370/**
371 * parport_get_port - increment a port's reference count
372 * @port: the port
373 *
Randy Dunlap7d469722006-06-25 05:49:29 -0700374 * This ensures that a struct parport pointer remains valid
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 * until the matching parport_put_port() call.
376 **/
377
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530378struct parport *parport_get_port(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379{
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530380 struct device *dev = get_device(&port->bus_dev);
381
382 return to_parport_dev(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +0530384EXPORT_SYMBOL(parport_get_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530386void parport_del_port(struct parport *port)
387{
388 device_unregister(&port->bus_dev);
389}
390EXPORT_SYMBOL(parport_del_port);
391
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392/**
393 * parport_put_port - decrement a port's reference count
394 * @port: the port
395 *
396 * This should be called once for each call to parport_get_port(),
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530397 * once the port is no longer needed. When the reference count reaches
398 * zero (port is no longer used), free_port is called.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 **/
400
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530401void parport_put_port(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402{
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530403 put_device(&port->bus_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +0530405EXPORT_SYMBOL(parport_put_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406
407/**
408 * parport_register_port - register a parallel port
409 * @base: base I/O address
410 * @irq: IRQ line
411 * @dma: DMA channel
412 * @ops: pointer to the port driver's port operations structure
413 *
414 * When a parallel port (lowlevel) driver finds a port that
415 * should be made available to parallel port device drivers, it
416 * should call parport_register_port(). The @base, @irq, and
417 * @dma parameters are for the convenience of port drivers, and
418 * for ports where they aren't meaningful needn't be set to
419 * anything special. They can be altered afterwards by adjusting
420 * the relevant members of the parport structure that is returned
421 * and represents the port. They should not be tampered with
422 * after calling parport_announce_port, however.
423 *
424 * If there are parallel port device drivers in the system that
425 * have registered themselves using parport_register_driver(),
426 * they are not told about the port at this time; that is done by
427 * parport_announce_port().
428 *
429 * The @ops structure is allocated by the caller, and must not be
430 * deallocated before calling parport_remove_port().
431 *
432 * If there is no memory to allocate a new parport structure,
433 * this function will return %NULL.
434 **/
435
436struct parport *parport_register_port(unsigned long base, int irq, int dma,
437 struct parport_operations *ops)
438{
439 struct list_head *l;
440 struct parport *tmp;
441 int num;
442 int device;
443 char *name;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530444 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
Alexandru Gheorghiuc32df4e2013-07-03 15:09:09 -0700446 tmp = kzalloc(sizeof(struct parport), GFP_KERNEL);
Sudip Mukherjee47ec57e2015-10-28 14:41:37 +0530447 if (!tmp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
450 /* Init our structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 tmp->base = base;
452 tmp->irq = irq;
453 tmp->dma = dma;
454 tmp->muxport = tmp->daisy = tmp->muxsel = -1;
455 tmp->modes = 0;
Sudip Mukherjeeb075e6f2015-10-28 14:41:34 +0530456 INIT_LIST_HEAD(&tmp->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 tmp->devices = tmp->cad = NULL;
458 tmp->flags = 0;
459 tmp->ops = ops;
460 tmp->physport = tmp;
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530461 memset(tmp->probe_info, 0, 5 * sizeof(struct parport_device_info));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 rwlock_init(&tmp->cad_lock);
463 spin_lock_init(&tmp->waitlist_lock);
464 spin_lock_init(&tmp->pardevice_lock);
465 tmp->ieee1284.mode = IEEE1284_MODE_COMPAT;
466 tmp->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
Thomas Gleixnera529f152010-09-07 14:32:34 +0000467 sema_init(&tmp->ieee1284.irq, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 tmp->spintime = parport_default_spintime;
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530469 atomic_set(&tmp->ref_count, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 INIT_LIST_HEAD(&tmp->full_list);
471
472 name = kmalloc(15, GFP_KERNEL);
473 if (!name) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 kfree(tmp);
475 return NULL;
476 }
477 /* Search for the lowest free parport number. */
478
479 spin_lock(&full_list_lock);
480 for (l = all_ports.next, num = 0; l != &all_ports; l = l->next, num++) {
481 struct parport *p = list_entry(l, struct parport, full_list);
482 if (p->number != num)
483 break;
484 }
485 tmp->portnum = tmp->number = num;
486 list_add_tail(&tmp->full_list, l);
487 spin_unlock(&full_list_lock);
488
489 /*
490 * Now that the portnum is known finish doing the Init.
491 */
492 sprintf(name, "parport%d", tmp->portnum = tmp->number);
493 tmp->name = name;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530494 tmp->bus_dev.bus = &parport_bus_type;
495 tmp->bus_dev.release = free_port;
496 dev_set_name(&tmp->bus_dev, name);
497 tmp->bus_dev.type = &parport_device_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
499 for (device = 0; device < 5; device++)
500 /* assume the worst */
501 tmp->probe_info[device].class = PARPORT_CLASS_LEGACY;
502
503 tmp->waithead = tmp->waittail = NULL;
504
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530505 ret = device_register(&tmp->bus_dev);
506 if (ret) {
507 put_device(&tmp->bus_dev);
508 return NULL;
509 }
510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 return tmp;
512}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +0530513EXPORT_SYMBOL(parport_register_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514
515/**
516 * parport_announce_port - tell device drivers about a parallel port
517 * @port: parallel port to announce
518 *
519 * After a port driver has registered a parallel port with
520 * parport_register_port, and performed any necessary
521 * initialisation or adjustments, it should call
522 * parport_announce_port() in order to notify all device drivers
523 * that have called parport_register_driver(). Their attach()
524 * functions will be called, with @port as the parameter.
525 **/
526
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530527void parport_announce_port(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528{
529 int i;
530
531#ifdef CONFIG_PARPORT_1284
532 /* Analyse the IEEE1284.3 topology of the port. */
533 parport_daisy_init(port);
534#endif
535
David Brownellc15a3832007-05-08 00:27:35 -0700536 if (!port->dev)
Sudip Mukherjeea1621882015-10-28 14:41:35 +0530537 printk(KERN_WARNING "%s: fix this legacy no-device port driver!\n",
538 port->name);
David Brownellc15a3832007-05-08 00:27:35 -0700539
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 parport_proc_register(port);
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800541 mutex_lock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 spin_lock_irq(&parportlist_lock);
543 list_add_tail(&port->list, &portlist);
544 for (i = 1; i < 3; i++) {
545 struct parport *slave = port->slaves[i-1];
546 if (slave)
547 list_add_tail(&slave->list, &portlist);
548 }
549 spin_unlock_irq(&parportlist_lock);
550
551 /* Let drivers know that new port(s) has arrived. */
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530552 attach_driver_chain(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 for (i = 1; i < 3; i++) {
554 struct parport *slave = port->slaves[i-1];
555 if (slave)
556 attach_driver_chain(slave);
557 }
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800558 mutex_unlock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +0530560EXPORT_SYMBOL(parport_announce_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561
562/**
563 * parport_remove_port - deregister a parallel port
564 * @port: parallel port to deregister
565 *
566 * When a parallel port driver is forcibly unloaded, or a
567 * parallel port becomes inaccessible, the port driver must call
568 * this function in order to deal with device drivers that still
569 * want to use it.
570 *
571 * The parport structure associated with the port has its
572 * operations structure replaced with one containing 'null'
573 * operations that return errors or just don't do anything.
574 *
575 * Any drivers that have registered themselves using
576 * parport_register_driver() are notified that the port is no
577 * longer accessible by having their detach() routines called
578 * with @port as the parameter.
579 **/
580
581void parport_remove_port(struct parport *port)
582{
583 int i;
584
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800585 mutex_lock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586
587 /* Spread the word. */
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530588 detach_driver_chain(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589
590#ifdef CONFIG_PARPORT_1284
591 /* Forget the IEEE1284.3 topology of the port. */
592 parport_daisy_fini(port);
593 for (i = 1; i < 3; i++) {
594 struct parport *slave = port->slaves[i-1];
595 if (!slave)
596 continue;
597 detach_driver_chain(slave);
598 parport_daisy_fini(slave);
599 }
600#endif
601
602 port->ops = &dead_ops;
603 spin_lock(&parportlist_lock);
604 list_del_init(&port->list);
605 for (i = 1; i < 3; i++) {
606 struct parport *slave = port->slaves[i-1];
607 if (slave)
608 list_del_init(&slave->list);
609 }
610 spin_unlock(&parportlist_lock);
611
Ingo Molnar14cc3e22006-03-26 01:37:14 -0800612 mutex_unlock(&registration_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613
614 parport_proc_unregister(port);
615
616 for (i = 1; i < 3; i++) {
617 struct parport *slave = port->slaves[i-1];
618 if (slave)
619 parport_put_port(slave);
620 }
621}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +0530622EXPORT_SYMBOL(parport_remove_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623
624/**
625 * parport_register_device - register a device on a parallel port
626 * @port: port to which the device is attached
627 * @name: a name to refer to the device
628 * @pf: preemption callback
629 * @kf: kick callback (wake-up)
630 * @irq_func: interrupt handler
631 * @flags: registration flags
632 * @handle: data for callback functions
633 *
634 * This function, called by parallel port device drivers,
635 * declares that a device is connected to a port, and tells the
636 * system all it needs to know.
637 *
638 * The @name is allocated by the caller and must not be
639 * deallocated until the caller calls @parport_unregister_device
640 * for that device.
641 *
642 * The preemption callback function, @pf, is called when this
643 * device driver has claimed access to the port but another
644 * device driver wants to use it. It is given @handle as its
645 * parameter, and should return zero if it is willing for the
646 * system to release the port to another driver on its behalf.
647 * If it wants to keep control of the port it should return
648 * non-zero, and no action will be taken. It is good manners for
649 * the driver to try to release the port at the earliest
650 * opportunity after its preemption callback rejects a preemption
651 * attempt. Note that if a preemption callback is happy for
652 * preemption to go ahead, there is no need to release the port;
653 * it is done automatically. This function may not block, as it
654 * may be called from interrupt context. If the device driver
655 * does not support preemption, @pf can be %NULL.
656 *
657 * The wake-up ("kick") callback function, @kf, is called when
658 * the port is available to be claimed for exclusive access; that
659 * is, parport_claim() is guaranteed to succeed when called from
660 * inside the wake-up callback function. If the driver wants to
661 * claim the port it should do so; otherwise, it need not take
662 * any action. This function may not block, as it may be called
663 * from interrupt context. If the device driver does not want to
664 * be explicitly invited to claim the port in this way, @kf can
665 * be %NULL.
666 *
667 * The interrupt handler, @irq_func, is called when an interrupt
668 * arrives from the parallel port. Note that if a device driver
669 * wants to use interrupts it should use parport_enable_irq(),
670 * and can also check the irq member of the parport structure
671 * representing the port.
672 *
673 * The parallel port (lowlevel) driver is the one that has called
674 * request_irq() and whose interrupt handler is called first.
675 * This handler does whatever needs to be done to the hardware to
676 * acknowledge the interrupt (for PC-style ports there is nothing
677 * special to be done). It then tells the IEEE 1284 code about
678 * the interrupt, which may involve reacting to an IEEE 1284
679 * event depending on the current IEEE 1284 phase. After this,
680 * it calls @irq_func. Needless to say, @irq_func will be called
681 * from interrupt context, and may not block.
682 *
683 * The %PARPORT_DEV_EXCL flag is for preventing port sharing, and
684 * so should only be used when sharing the port with other device
685 * drivers is impossible and would lead to incorrect behaviour.
686 * Use it sparingly! Normally, @flags will be zero.
687 *
688 * This function returns a pointer to a structure that represents
689 * the device on the port, or %NULL if there is not enough memory
690 * to allocate space for that structure.
691 **/
692
693struct pardevice *
694parport_register_device(struct parport *port, const char *name,
695 int (*pf)(void *), void (*kf)(void *),
Sudip Mukherjee657e24d2015-10-28 14:41:31 +0530696 void (*irq_func)(void *),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 int flags, void *handle)
698{
699 struct pardevice *tmp;
700
701 if (port->physport->flags & PARPORT_FLAG_EXCL) {
702 /* An exclusive device is registered. */
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530703 printk(KERN_DEBUG "%s: no more devices allowed\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 port->name);
705 return NULL;
706 }
707
708 if (flags & PARPORT_DEV_LURK) {
709 if (!pf || !kf) {
710 printk(KERN_INFO "%s: refused to register lurking device (%s) without callbacks\n", port->name, name);
711 return NULL;
712 }
713 }
714
Sudip Mukherjee50566ac82015-06-12 15:20:20 +0530715 if (flags & PARPORT_DEV_EXCL) {
716 if (port->physport->devices) {
717 /*
718 * If a device is already registered and this new
719 * device wants exclusive access, then no need to
720 * continue as we can not grant exclusive access to
721 * this device.
722 */
723 pr_err("%s: cannot grant exclusive access for device %s\n",
724 port->name, name);
725 return NULL;
726 }
727 }
728
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +0530729 /*
730 * We up our own module reference count, and that of the port
731 * on which a device is to be registered, to ensure that
732 * neither of us gets unloaded while we sleep in (e.g.)
733 * kmalloc.
734 */
Sudip Mukherjee13efa752015-10-28 14:41:36 +0530735 if (!try_module_get(port->ops->owner))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 return NULL;
Sudip Mukherjee657e24d2015-10-28 14:41:31 +0530737
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530738 parport_get_port(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739
740 tmp = kmalloc(sizeof(struct pardevice), GFP_KERNEL);
Sudip Mukherjeeb95b9d62015-10-28 14:41:38 +0530741 if (!tmp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743
744 tmp->state = kmalloc(sizeof(struct parport_state), GFP_KERNEL);
Sudip Mukherjeeb95b9d62015-10-28 14:41:38 +0530745 if (!tmp->state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 goto out_free_pardevice;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747
748 tmp->name = name;
749 tmp->port = port;
750 tmp->daisy = -1;
751 tmp->preempt = pf;
752 tmp->wakeup = kf;
753 tmp->private = handle;
754 tmp->flags = flags;
755 tmp->irq_func = irq_func;
756 tmp->waiting = 0;
757 tmp->timeout = 5 * HZ;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530758 tmp->devmodel = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
760 /* Chain this onto the list */
761 tmp->prev = NULL;
762 /*
763 * This function must not run from an irq handler so we don' t need
764 * to clear irq on the local CPU. -arca
765 */
766 spin_lock(&port->physport->pardevice_lock);
767
768 if (flags & PARPORT_DEV_EXCL) {
769 if (port->physport->devices) {
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530770 spin_unlock(&port->physport->pardevice_lock);
771 printk(KERN_DEBUG
Sudip Mukherjeea1621882015-10-28 14:41:35 +0530772 "%s: cannot grant exclusive access for device %s\n",
773 port->name, name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 goto out_free_all;
775 }
776 port->flags |= PARPORT_FLAG_EXCL;
777 }
778
779 tmp->next = port->physport->devices;
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +0530780 wmb(); /*
781 * Make sure that tmp->next is written before it's
782 * added to the list; see comments marked 'no locking
783 * required'
784 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 if (port->physport->devices)
786 port->physport->devices->prev = tmp;
787 port->physport->devices = tmp;
788 spin_unlock(&port->physport->pardevice_lock);
789
790 init_waitqueue_head(&tmp->wait_q);
791 tmp->timeslice = parport_default_timeslice;
792 tmp->waitnext = tmp->waitprev = NULL;
793
794 /*
795 * This has to be run as last thing since init_state may need other
796 * pardevice fields. -arca
797 */
798 port->ops->init_state(tmp, tmp->state);
Alan Cox05ad7092009-06-02 16:58:10 +0100799 if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) {
800 port->proc_device = tmp;
801 parport_device_proc_register(tmp);
802 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 return tmp;
804
805 out_free_all:
Jesper Juhl6044ec82005-11-07 01:01:32 -0800806 kfree(tmp->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 out_free_pardevice:
Jesper Juhl6044ec82005-11-07 01:01:32 -0800808 kfree(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 out:
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530810 parport_put_port(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 module_put(port->ops->owner);
812
813 return NULL;
814}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +0530815EXPORT_SYMBOL(parport_register_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530817static void free_pardevice(struct device *dev)
818{
819 struct pardevice *par_dev = to_pardevice(dev);
820
821 kfree(par_dev->name);
822 kfree(par_dev);
823}
824
825struct pardevice *
826parport_register_dev_model(struct parport *port, const char *name,
827 const struct pardev_cb *par_dev_cb, int id)
828{
829 struct pardevice *par_dev;
830 int ret;
831 char *devname;
832
833 if (port->physport->flags & PARPORT_FLAG_EXCL) {
834 /* An exclusive device is registered. */
835 pr_err("%s: no more devices allowed\n", port->name);
836 return NULL;
837 }
838
839 if (par_dev_cb->flags & PARPORT_DEV_LURK) {
840 if (!par_dev_cb->preempt || !par_dev_cb->wakeup) {
841 pr_info("%s: refused to register lurking device (%s) without callbacks\n",
842 port->name, name);
843 return NULL;
844 }
845 }
846
Sudip Mukherjee50566ac82015-06-12 15:20:20 +0530847 if (par_dev_cb->flags & PARPORT_DEV_EXCL) {
848 if (port->physport->devices) {
849 /*
850 * If a device is already registered and this new
851 * device wants exclusive access, then no need to
852 * continue as we can not grant exclusive access to
853 * this device.
854 */
855 pr_err("%s: cannot grant exclusive access for device %s\n",
856 port->name, name);
857 return NULL;
858 }
859 }
860
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530861 if (!try_module_get(port->ops->owner))
862 return NULL;
863
864 parport_get_port(port);
865
866 par_dev = kzalloc(sizeof(*par_dev), GFP_KERNEL);
867 if (!par_dev)
868 goto err_put_port;
869
870 par_dev->state = kzalloc(sizeof(*par_dev->state), GFP_KERNEL);
871 if (!par_dev->state)
872 goto err_put_par_dev;
873
874 devname = kstrdup(name, GFP_KERNEL);
875 if (!devname)
876 goto err_free_par_dev;
877
878 par_dev->name = devname;
879 par_dev->port = port;
880 par_dev->daisy = -1;
881 par_dev->preempt = par_dev_cb->preempt;
882 par_dev->wakeup = par_dev_cb->wakeup;
883 par_dev->private = par_dev_cb->private;
884 par_dev->flags = par_dev_cb->flags;
885 par_dev->irq_func = par_dev_cb->irq_func;
886 par_dev->waiting = 0;
887 par_dev->timeout = 5 * HZ;
888
889 par_dev->dev.parent = &port->bus_dev;
890 par_dev->dev.bus = &parport_bus_type;
891 ret = dev_set_name(&par_dev->dev, "%s.%d", devname, id);
892 if (ret)
893 goto err_free_devname;
894 par_dev->dev.release = free_pardevice;
895 par_dev->devmodel = true;
896 ret = device_register(&par_dev->dev);
Sudip Mukherjee68d35c72015-06-15 20:05:51 +0530897 if (ret) {
898 put_device(&par_dev->dev);
899 goto err_put_port;
900 }
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530901
902 /* Chain this onto the list */
903 par_dev->prev = NULL;
904 /*
905 * This function must not run from an irq handler so we don' t need
906 * to clear irq on the local CPU. -arca
907 */
908 spin_lock(&port->physport->pardevice_lock);
909
910 if (par_dev_cb->flags & PARPORT_DEV_EXCL) {
911 if (port->physport->devices) {
912 spin_unlock(&port->physport->pardevice_lock);
913 pr_debug("%s: cannot grant exclusive access for device %s\n",
914 port->name, name);
Sudip Mukherjeecabea692015-06-15 20:05:49 +0530915 device_unregister(&par_dev->dev);
916 goto err_put_port;
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530917 }
918 port->flags |= PARPORT_FLAG_EXCL;
919 }
920
921 par_dev->next = port->physport->devices;
922 wmb(); /*
923 * Make sure that tmp->next is written before it's
924 * added to the list; see comments marked 'no locking
925 * required'
926 */
927 if (port->physport->devices)
928 port->physport->devices->prev = par_dev;
929 port->physport->devices = par_dev;
930 spin_unlock(&port->physport->pardevice_lock);
931
932 init_waitqueue_head(&par_dev->wait_q);
933 par_dev->timeslice = parport_default_timeslice;
934 par_dev->waitnext = NULL;
935 par_dev->waitprev = NULL;
936
937 /*
938 * This has to be run as last thing since init_state may need other
939 * pardevice fields. -arca
940 */
941 port->ops->init_state(par_dev, par_dev->state);
942 port->proc_device = par_dev;
943 parport_device_proc_register(par_dev);
944
945 return par_dev;
946
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +0530947err_free_devname:
948 kfree(devname);
949err_free_par_dev:
950 kfree(par_dev->state);
951err_put_par_dev:
952 if (!par_dev->devmodel)
953 kfree(par_dev);
954err_put_port:
955 parport_put_port(port);
956 module_put(port->ops->owner);
957
958 return NULL;
959}
960EXPORT_SYMBOL(parport_register_dev_model);
961
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962/**
963 * parport_unregister_device - deregister a device on a parallel port
964 * @dev: pointer to structure representing device
965 *
966 * This undoes the effect of parport_register_device().
967 **/
968
969void parport_unregister_device(struct pardevice *dev)
970{
971 struct parport *port;
972
973#ifdef PARPORT_PARANOID
Sudip Mukherjeeb95b9d62015-10-28 14:41:38 +0530974 if (!dev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 printk(KERN_ERR "parport_unregister_device: passed NULL\n");
976 return;
977 }
978#endif
979
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 port = dev->port->physport;
981
Alan Cox05ad7092009-06-02 16:58:10 +0100982 if (port->proc_device == dev) {
983 port->proc_device = NULL;
984 clear_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags);
985 parport_device_proc_unregister(dev);
986 }
987
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 if (port->cad == dev) {
989 printk(KERN_DEBUG "%s: %s forgot to release port\n",
990 port->name, dev->name);
Sudip Mukherjeee732b932015-10-28 14:41:39 +0530991 parport_release(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 }
993
994 spin_lock(&port->pardevice_lock);
995 if (dev->next)
996 dev->next->prev = dev->prev;
997 if (dev->prev)
998 dev->prev->next = dev->next;
999 else
1000 port->devices = dev->next;
1001
1002 if (dev->flags & PARPORT_DEV_EXCL)
1003 port->flags &= ~PARPORT_FLAG_EXCL;
1004
1005 spin_unlock(&port->pardevice_lock);
1006
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +05301007 /*
1008 * Make sure we haven't left any pointers around in the wait
1009 * list.
1010 */
Alexander Gordeevcbeb4b72011-01-25 15:07:16 -08001011 spin_lock_irq(&port->waitlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 if (dev->waitprev || dev->waitnext || port->waithead == dev) {
1013 if (dev->waitprev)
1014 dev->waitprev->waitnext = dev->waitnext;
1015 else
1016 port->waithead = dev->waitnext;
1017 if (dev->waitnext)
1018 dev->waitnext->waitprev = dev->waitprev;
1019 else
1020 port->waittail = dev->waitprev;
1021 }
Alexander Gordeevcbeb4b72011-01-25 15:07:16 -08001022 spin_unlock_irq(&port->waitlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023
1024 kfree(dev->state);
Sudip Mukherjee6fa45a22015-05-20 20:56:57 +05301025 if (dev->devmodel)
1026 device_unregister(&dev->dev);
1027 else
1028 kfree(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029
1030 module_put(port->ops->owner);
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301031 parport_put_port(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +05301033EXPORT_SYMBOL(parport_unregister_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034
1035/**
1036 * parport_find_number - find a parallel port by number
1037 * @number: parallel port number
1038 *
1039 * This returns the parallel port with the specified number, or
1040 * %NULL if there is none.
1041 *
1042 * There is an implicit parport_get_port() done already; to throw
1043 * away the reference to the port that parport_find_number()
1044 * gives you, use parport_put_port().
1045 */
1046
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301047struct parport *parport_find_number(int number)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048{
1049 struct parport *port, *result = NULL;
1050
1051 if (list_empty(&portlist))
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301052 get_lowlevel_driver();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301054 spin_lock(&parportlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055 list_for_each_entry(port, &portlist, list) {
1056 if (port->number == number) {
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301057 result = parport_get_port(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 break;
1059 }
1060 }
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301061 spin_unlock(&parportlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 return result;
1063}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +05301064EXPORT_SYMBOL(parport_find_number);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065
1066/**
1067 * parport_find_base - find a parallel port by base address
1068 * @base: base I/O address
1069 *
1070 * This returns the parallel port with the specified base
1071 * address, or %NULL if there is none.
1072 *
1073 * There is an implicit parport_get_port() done already; to throw
1074 * away the reference to the port that parport_find_base()
1075 * gives you, use parport_put_port().
1076 */
1077
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301078struct parport *parport_find_base(unsigned long base)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079{
1080 struct parport *port, *result = NULL;
1081
1082 if (list_empty(&portlist))
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301083 get_lowlevel_driver();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301085 spin_lock(&parportlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086 list_for_each_entry(port, &portlist, list) {
1087 if (port->base == base) {
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301088 result = parport_get_port(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089 break;
1090 }
1091 }
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301092 spin_unlock(&parportlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 return result;
1094}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +05301095EXPORT_SYMBOL(parport_find_base);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096
1097/**
1098 * parport_claim - claim access to a parallel port device
1099 * @dev: pointer to structure representing a device on the port
1100 *
1101 * This function will not block and so can be used from interrupt
1102 * context. If parport_claim() succeeds in claiming access to
1103 * the port it returns zero and the port is available to use. It
1104 * may fail (returning non-zero) if the port is in use by another
1105 * driver and that driver is not willing to relinquish control of
1106 * the port.
1107 **/
1108
1109int parport_claim(struct pardevice *dev)
1110{
1111 struct pardevice *oldcad;
1112 struct parport *port = dev->port->physport;
1113 unsigned long flags;
1114
1115 if (port->cad == dev) {
1116 printk(KERN_INFO "%s: %s already owner\n",
1117 dev->port->name,dev->name);
1118 return 0;
1119 }
1120
1121 /* Preempt any current device */
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301122 write_lock_irqsave(&port->cad_lock, flags);
Sudip Mukherjeee0a7f1f2015-10-28 14:41:40 +05301123 oldcad = port->cad;
1124 if (oldcad) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 if (oldcad->preempt) {
1126 if (oldcad->preempt(oldcad->private))
1127 goto blocked;
1128 port->ops->save_state(port, dev->state);
1129 } else
1130 goto blocked;
1131
1132 if (port->cad != oldcad) {
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +05301133 /*
1134 * I think we'll actually deadlock rather than
1135 * get here, but just in case..
1136 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 printk(KERN_WARNING
1138 "%s: %s released port when preempted!\n",
1139 port->name, oldcad->name);
1140 if (port->cad)
1141 goto blocked;
1142 }
1143 }
1144
1145 /* Can't fail from now on, so mark ourselves as no longer waiting. */
1146 if (dev->waiting & 1) {
1147 dev->waiting = 0;
1148
1149 /* Take ourselves out of the wait list again. */
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301150 spin_lock_irq(&port->waitlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151 if (dev->waitprev)
1152 dev->waitprev->waitnext = dev->waitnext;
1153 else
1154 port->waithead = dev->waitnext;
1155 if (dev->waitnext)
1156 dev->waitnext->waitprev = dev->waitprev;
1157 else
1158 port->waittail = dev->waitprev;
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301159 spin_unlock_irq(&port->waitlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 dev->waitprev = dev->waitnext = NULL;
1161 }
1162
1163 /* Now we do the change of devices */
1164 port->cad = dev;
1165
1166#ifdef CONFIG_PARPORT_1284
1167 /* If it's a mux port, select it. */
1168 if (dev->port->muxport >= 0) {
1169 /* FIXME */
1170 port->muxsel = dev->port->muxport;
1171 }
1172
1173 /* If it's a daisy chain device, select it. */
1174 if (dev->daisy >= 0) {
1175 /* This could be lazier. */
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301176 if (!parport_daisy_select(port, dev->daisy,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 IEEE1284_MODE_COMPAT))
1178 port->daisy = dev->daisy;
1179 }
1180#endif /* IEEE1284.3 support */
1181
1182 /* Restore control registers */
1183 port->ops->restore_state(port, dev->state);
1184 write_unlock_irqrestore(&port->cad_lock, flags);
1185 dev->time = jiffies;
1186 return 0;
1187
1188blocked:
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +05301189 /*
1190 * If this is the first time we tried to claim the port, register an
1191 * interest. This is only allowed for devices sleeping in
1192 * parport_claim_or_block(), or those with a wakeup function.
1193 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194
1195 /* The cad_lock is still held for writing here */
1196 if (dev->waiting & 2 || dev->wakeup) {
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301197 spin_lock(&port->waitlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 if (test_and_set_bit(0, &dev->waiting) == 0) {
1199 /* First add ourselves to the end of the wait list. */
1200 dev->waitnext = NULL;
1201 dev->waitprev = port->waittail;
1202 if (port->waittail) {
1203 port->waittail->waitnext = dev;
1204 port->waittail = dev;
1205 } else
1206 port->waithead = port->waittail = dev;
1207 }
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301208 spin_unlock(&port->waitlist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209 }
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301210 write_unlock_irqrestore(&port->cad_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211 return -EAGAIN;
1212}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +05301213EXPORT_SYMBOL(parport_claim);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214
1215/**
1216 * parport_claim_or_block - claim access to a parallel port device
1217 * @dev: pointer to structure representing a device on the port
1218 *
1219 * This behaves like parport_claim(), but will block if necessary
1220 * to wait for the port to be free. A return value of 1
1221 * indicates that it slept; 0 means that it succeeded without
1222 * needing to sleep. A negative error code indicates failure.
1223 **/
1224
1225int parport_claim_or_block(struct pardevice *dev)
1226{
1227 int r;
1228
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +05301229 /*
1230 * Signal to parport_claim() that we can wait even without a
1231 * wakeup function.
1232 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 dev->waiting = 2;
1234
1235 /* Try to claim the port. If this fails, we need to sleep. */
1236 r = parport_claim(dev);
1237 if (r == -EAGAIN) {
1238#ifdef PARPORT_DEBUG_SHARING
1239 printk(KERN_DEBUG "%s: parport_claim() returned -EAGAIN\n", dev->name);
1240#endif
1241 /*
1242 * FIXME!!! Use the proper locking for dev->waiting,
1243 * and make this use the "wait_event_interruptible()"
1244 * interfaces. The cli/sti that used to be here
1245 * did nothing.
1246 *
1247 * See also parport_release()
1248 */
1249
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +05301250 /*
1251 * If dev->waiting is clear now, an interrupt
1252 * gave us the port and we would deadlock if we slept.
1253 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 if (dev->waiting) {
Arnd Bergmann76ae0532014-02-26 12:01:49 +01001255 wait_event_interruptible(dev->wait_q,
1256 !dev->waiting);
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301257 if (signal_pending(current))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 return -EINTR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259 r = 1;
1260 } else {
1261 r = 0;
1262#ifdef PARPORT_DEBUG_SHARING
1263 printk(KERN_DEBUG "%s: didn't sleep in parport_claim_or_block()\n",
1264 dev->name);
1265#endif
1266 }
1267
1268#ifdef PARPORT_DEBUG_SHARING
1269 if (dev->port->physport->cad != dev)
Sudip Mukherjeea1621882015-10-28 14:41:35 +05301270 printk(KERN_DEBUG "%s: exiting parport_claim_or_block but %s owns port!\n",
1271 dev->name, dev->port->physport->cad ?
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 dev->port->physport->cad->name:"nobody");
1273#endif
1274 }
1275 dev->waiting = 0;
1276 return r;
1277}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +05301278EXPORT_SYMBOL(parport_claim_or_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279
1280/**
1281 * parport_release - give up access to a parallel port device
1282 * @dev: pointer to structure representing parallel port device
1283 *
1284 * This function cannot fail, but it should not be called without
1285 * the port claimed. Similarly, if the port is already claimed
1286 * you should not try claiming it again.
1287 **/
1288
1289void parport_release(struct pardevice *dev)
1290{
1291 struct parport *port = dev->port->physport;
1292 struct pardevice *pd;
1293 unsigned long flags;
1294
1295 /* Make sure that dev is the current device */
1296 write_lock_irqsave(&port->cad_lock, flags);
1297 if (port->cad != dev) {
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301298 write_unlock_irqrestore(&port->cad_lock, flags);
Sudip Mukherjeea1621882015-10-28 14:41:35 +05301299 printk(KERN_WARNING "%s: %s tried to release parport when not owner\n",
1300 port->name, dev->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 return;
1302 }
1303
1304#ifdef CONFIG_PARPORT_1284
1305 /* If this is on a mux port, deselect it. */
1306 if (dev->port->muxport >= 0) {
1307 /* FIXME */
1308 port->muxsel = -1;
1309 }
1310
1311 /* If this is a daisy device, deselect it. */
1312 if (dev->daisy >= 0) {
Sudip Mukherjeee732b932015-10-28 14:41:39 +05301313 parport_daisy_deselect_all(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 port->daisy = -1;
1315 }
1316#endif
1317
1318 port->cad = NULL;
1319 write_unlock_irqrestore(&port->cad_lock, flags);
1320
1321 /* Save control registers */
1322 port->ops->save_state(port, dev->state);
1323
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +05301324 /*
1325 * If anybody is waiting, find out who's been there longest and
1326 * then wake them up. (Note: no locking required)
1327 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328 /* !!! LOCKING IS NEEDED HERE */
1329 for (pd = port->waithead; pd; pd = pd->waitnext) {
1330 if (pd->waiting & 2) { /* sleeping in claim_or_block */
1331 parport_claim(pd);
1332 if (waitqueue_active(&pd->wait_q))
1333 wake_up_interruptible(&pd->wait_q);
1334 return;
1335 } else if (pd->wakeup) {
1336 pd->wakeup(pd->private);
1337 if (dev->port->cad) /* racy but no matter */
1338 return;
1339 } else {
1340 printk(KERN_ERR "%s: don't know how to wake %s\n", port->name, pd->name);
1341 }
1342 }
1343
Sudip Mukherjee7b7a0a32015-10-28 14:41:33 +05301344 /*
1345 * Nobody was waiting, so walk the list to see if anyone is
1346 * interested in being woken up. (Note: no locking required)
1347 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348 /* !!! LOCKING IS NEEDED HERE */
Sudip Mukherjeeb95b9d62015-10-28 14:41:38 +05301349 for (pd = port->devices; !port->cad && pd; pd = pd->next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350 if (pd->wakeup && pd != dev)
1351 pd->wakeup(pd->private);
1352 }
1353}
Sudip Mukherjee27c6db22015-10-28 14:41:32 +05301354EXPORT_SYMBOL(parport_release);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355
Jeff Garzik3f2e40d2007-10-19 01:42:14 -04001356irqreturn_t parport_irq_handler(int irq, void *dev_id)
1357{
1358 struct parport *port = dev_id;
1359
Jeff Garzikf230d102007-10-19 01:56:02 -04001360 parport_generic_irq(port);
Jeff Garzik3f2e40d2007-10-19 01:42:14 -04001361
1362 return IRQ_HANDLED;
1363}
Jeff Garzik3f2e40d2007-10-19 01:42:14 -04001364EXPORT_SYMBOL(parport_irq_handler);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365
1366MODULE_LICENSE("GPL");