2 * Parallel-port resource manager code.
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>
10 * based on work by Grant Guenther <grant@torque.net>
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.
18 #undef PARPORT_DEBUG_SHARING /* undef for production */
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/threads.h>
23 #include <linux/parport.h>
24 #include <linux/delay.h>
25 #include <linux/errno.h>
26 #include <linux/interrupt.h>
27 #include <linux/ioport.h>
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/sched.h>
31 #include <linux/kmod.h>
32 #include <linux/device.h>
34 #include <linux/spinlock.h>
35 #include <linux/mutex.h>
38 #undef PARPORT_PARANOID
40 #define PARPORT_DEFAULT_TIMESLICE (HZ/5)
42 unsigned long parport_default_timeslice
= PARPORT_DEFAULT_TIMESLICE
;
43 int parport_default_spintime
= DEFAULT_SPIN_TIME
;
45 static LIST_HEAD(portlist
);
46 static DEFINE_SPINLOCK(parportlist_lock
);
48 /* list of all allocated ports, sorted by ->number */
49 static LIST_HEAD(all_ports
);
50 static DEFINE_SPINLOCK(full_list_lock
);
52 static LIST_HEAD(drivers
);
54 static DEFINE_MUTEX(registration_lock
);
56 /* What you can do to a port that's gone away.. */
57 static void dead_write_lines (struct parport
*p
, unsigned char b
){}
58 static unsigned char dead_read_lines (struct parport
*p
) { return 0; }
59 static unsigned char dead_frob_lines (struct parport
*p
, unsigned char b
,
60 unsigned char c
) { return 0; }
61 static void dead_onearg (struct parport
*p
){}
62 static void dead_initstate (struct pardevice
*d
, struct parport_state
*s
) { }
63 static void dead_state (struct parport
*p
, struct parport_state
*s
) { }
64 static size_t dead_write (struct parport
*p
, const void *b
, size_t l
, int f
)
66 static size_t dead_read (struct parport
*p
, void *b
, size_t l
, int f
)
68 static struct parport_operations dead_ops
= {
69 .write_data
= dead_write_lines
, /* data */
70 .read_data
= dead_read_lines
,
72 .write_control
= dead_write_lines
, /* control */
73 .read_control
= dead_read_lines
,
74 .frob_control
= dead_frob_lines
,
76 .read_status
= dead_read_lines
, /* status */
78 .enable_irq
= dead_onearg
, /* enable_irq */
79 .disable_irq
= dead_onearg
, /* disable_irq */
81 .data_forward
= dead_onearg
, /* data_forward */
82 .data_reverse
= dead_onearg
, /* data_reverse */
84 .init_state
= dead_initstate
, /* init_state */
85 .save_state
= dead_state
,
86 .restore_state
= dead_state
,
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
,
93 .ecp_write_data
= dead_write
, /* ecp */
94 .ecp_read_data
= dead_read
,
95 .ecp_write_addr
= dead_write
,
97 .compat_write_data
= dead_write
, /* compat */
98 .nibble_read_data
= dead_read
, /* nibble */
99 .byte_read_data
= dead_read
, /* byte */
104 static struct device_type parport_device_type
= {
108 static int is_parport(struct device
*dev
)
110 return dev
->type
== &parport_device_type
;
113 static int parport_probe(struct device
*dev
)
115 struct parport_driver
*drv
;
120 drv
= to_parport_driver(dev
->driver
);
122 /* if driver has not defined a custom probe */
123 struct pardevice
*par_dev
= to_pardevice(dev
);
125 if (strcmp(par_dev
->name
, drv
->name
))
129 /* if driver defined its own probe */
130 return drv
->probe(to_pardevice(dev
));
133 static struct bus_type parport_bus_type
= {
135 .probe
= parport_probe
,
138 int parport_bus_init(void)
140 return bus_register(&parport_bus_type
);
143 void parport_bus_exit(void)
145 bus_unregister(&parport_bus_type
);
149 * iterates through all the drivers registered with the bus and sends the port
150 * details to the match_port callback of the driver, so that the driver can
151 * know about the new port that just registered with the bus and decide if it
152 * wants to use this new port.
154 static int driver_check(struct device_driver
*dev_drv
, void *_port
)
156 struct parport
*port
= _port
;
157 struct parport_driver
*drv
= to_parport_driver(dev_drv
);
160 drv
->match_port(port
);
164 /* Call attach(port) for each registered driver. */
165 static void attach_driver_chain(struct parport
*port
)
167 /* caller has exclusive registration_lock */
168 struct parport_driver
*drv
;
170 list_for_each_entry(drv
, &drivers
, list
)
174 * call the driver_check function of the drivers registered in
178 bus_for_each_drv(&parport_bus_type
, NULL
, port
, driver_check
);
181 static int driver_detach(struct device_driver
*_drv
, void *_port
)
183 struct parport
*port
= _port
;
184 struct parport_driver
*drv
= to_parport_driver(_drv
);
191 /* Call detach(port) for each registered driver. */
192 static void detach_driver_chain(struct parport
*port
)
194 struct parport_driver
*drv
;
195 /* caller has exclusive registration_lock */
196 list_for_each_entry(drv
, &drivers
, list
)
200 * call the detach function of the drivers registered in
204 bus_for_each_drv(&parport_bus_type
, NULL
, port
, driver_detach
);
207 /* Ask kmod for some lowlevel drivers. */
208 static void get_lowlevel_driver (void)
211 * There is no actual module called this: you should set
212 * up an alias for modutils.
214 request_module ("parport_lowlevel");
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.
223 static int port_check(struct device
*dev
, void *dev_drv
)
225 struct parport_driver
*drv
= dev_drv
;
227 /* only send ports, do not send other devices connected to bus */
229 drv
->match_port(to_parport_dev(dev
));
234 * parport_register_driver - register a parallel port device driver
235 * @drv: structure describing the driver
236 * @owner: owner module of drv
237 * @mod_name: module name string
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.
243 * If devmodel is true then the new device model is used
246 * The @drv structure is allocated by the caller and must not be
247 * deallocated until after calling parport_unregister_driver().
249 * If using the non device model:
250 * The driver's attach() function may block. The port that
251 * attach() is given will be valid for the duration of the
252 * callback, but if the driver wants to take a copy of the
253 * pointer it must call parport_get_port() to do so. Calling
254 * parport_register_device() on that port will do this for you.
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.
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.
266 int __parport_register_driver(struct parport_driver
*drv
, struct module
*owner
,
267 const char *mod_name
)
269 if (list_empty(&portlist
))
270 get_lowlevel_driver ();
273 /* using device model */
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
);
285 mutex_lock(®istration_lock
);
287 bus_for_each_dev(&parport_bus_type
, NULL
, drv
,
289 mutex_unlock(®istration_lock
);
291 struct parport
*port
;
293 drv
->devmodel
= false;
295 mutex_lock(®istration_lock
);
296 list_for_each_entry(port
, &portlist
, list
)
298 list_add(&drv
->list
, &drivers
);
299 mutex_unlock(®istration_lock
);
304 EXPORT_SYMBOL(__parport_register_driver
);
306 static int port_detach(struct device
*dev
, void *_drv
)
308 struct parport_driver
*drv
= _drv
;
310 if (is_parport(dev
) && drv
->detach
)
311 drv
->detach(to_parport_dev(dev
));
317 * parport_unregister_driver - deregister a parallel port device driver
318 * @drv: structure describing the driver that was given to
319 * parport_register_driver()
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.
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.
329 * All the driver's attach() and detach() calls are guaranteed to have
330 * finished by the time this function returns.
333 void parport_unregister_driver (struct parport_driver
*drv
)
335 struct parport
*port
;
337 mutex_lock(®istration_lock
);
339 bus_for_each_dev(&parport_bus_type
, NULL
, drv
, port_detach
);
340 driver_unregister(&drv
->driver
);
342 list_del_init(&drv
->list
);
343 list_for_each_entry(port
, &portlist
, list
)
346 mutex_unlock(®istration_lock
);
348 EXPORT_SYMBOL(parport_unregister_driver
);
350 static void free_port(struct device
*dev
)
353 struct parport
*port
= to_parport_dev(dev
);
355 spin_lock(&full_list_lock
);
356 list_del(&port
->full_list
);
357 spin_unlock(&full_list_lock
);
358 for (d
= 0; d
< 5; d
++) {
359 kfree(port
->probe_info
[d
].class_name
);
360 kfree(port
->probe_info
[d
].mfr
);
361 kfree(port
->probe_info
[d
].model
);
362 kfree(port
->probe_info
[d
].cmdset
);
363 kfree(port
->probe_info
[d
].description
);
371 * parport_get_port - increment a port's reference count
374 * This ensures that a struct parport pointer remains valid
375 * until the matching parport_put_port() call.
378 struct parport
*parport_get_port (struct parport
*port
)
380 struct device
*dev
= get_device(&port
->bus_dev
);
382 return to_parport_dev(dev
);
384 EXPORT_SYMBOL(parport_get_port
);
386 void parport_del_port(struct parport
*port
)
388 device_unregister(&port
->bus_dev
);
390 EXPORT_SYMBOL(parport_del_port
);
393 * parport_put_port - decrement a port's reference count
396 * This should be called once for each call to parport_get_port(),
397 * once the port is no longer needed. When the reference count reaches
398 * zero (port is no longer used), free_port is called.
401 void parport_put_port (struct parport
*port
)
403 put_device(&port
->bus_dev
);
405 EXPORT_SYMBOL(parport_put_port
);
408 * parport_register_port - register a parallel port
409 * @base: base I/O address
412 * @ops: pointer to the port driver's port operations structure
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.
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().
429 * The @ops structure is allocated by the caller, and must not be
430 * deallocated before calling parport_remove_port().
432 * If there is no memory to allocate a new parport structure,
433 * this function will return %NULL.
436 struct parport
*parport_register_port(unsigned long base
, int irq
, int dma
,
437 struct parport_operations
*ops
)
446 tmp
= kzalloc(sizeof(struct parport
), GFP_KERNEL
);
448 printk(KERN_WARNING
"parport: memory squeeze\n");
452 /* Init our structure */
456 tmp
->muxport
= tmp
->daisy
= tmp
->muxsel
= -1;
458 INIT_LIST_HEAD(&tmp
->list
);
459 tmp
->devices
= tmp
->cad
= NULL
;
463 memset (tmp
->probe_info
, 0, 5 * sizeof (struct parport_device_info
));
464 rwlock_init(&tmp
->cad_lock
);
465 spin_lock_init(&tmp
->waitlist_lock
);
466 spin_lock_init(&tmp
->pardevice_lock
);
467 tmp
->ieee1284
.mode
= IEEE1284_MODE_COMPAT
;
468 tmp
->ieee1284
.phase
= IEEE1284_PH_FWD_IDLE
;
469 sema_init(&tmp
->ieee1284
.irq
, 0);
470 tmp
->spintime
= parport_default_spintime
;
471 atomic_set (&tmp
->ref_count
, 1);
472 INIT_LIST_HEAD(&tmp
->full_list
);
474 name
= kmalloc(15, GFP_KERNEL
);
476 printk(KERN_ERR
"parport: memory squeeze\n");
480 /* Search for the lowest free parport number. */
482 spin_lock(&full_list_lock
);
483 for (l
= all_ports
.next
, num
= 0; l
!= &all_ports
; l
= l
->next
, num
++) {
484 struct parport
*p
= list_entry(l
, struct parport
, full_list
);
485 if (p
->number
!= num
)
488 tmp
->portnum
= tmp
->number
= num
;
489 list_add_tail(&tmp
->full_list
, l
);
490 spin_unlock(&full_list_lock
);
493 * Now that the portnum is known finish doing the Init.
495 sprintf(name
, "parport%d", tmp
->portnum
= tmp
->number
);
497 tmp
->bus_dev
.bus
= &parport_bus_type
;
498 tmp
->bus_dev
.release
= free_port
;
499 dev_set_name(&tmp
->bus_dev
, name
);
500 tmp
->bus_dev
.type
= &parport_device_type
;
502 for (device
= 0; device
< 5; device
++)
503 /* assume the worst */
504 tmp
->probe_info
[device
].class = PARPORT_CLASS_LEGACY
;
506 tmp
->waithead
= tmp
->waittail
= NULL
;
508 ret
= device_register(&tmp
->bus_dev
);
510 put_device(&tmp
->bus_dev
);
516 EXPORT_SYMBOL(parport_register_port
);
519 * parport_announce_port - tell device drivers about a parallel port
520 * @port: parallel port to announce
522 * After a port driver has registered a parallel port with
523 * parport_register_port, and performed any necessary
524 * initialisation or adjustments, it should call
525 * parport_announce_port() in order to notify all device drivers
526 * that have called parport_register_driver(). Their attach()
527 * functions will be called, with @port as the parameter.
530 void parport_announce_port (struct parport
*port
)
534 #ifdef CONFIG_PARPORT_1284
535 /* Analyse the IEEE1284.3 topology of the port. */
536 parport_daisy_init(port
);
540 printk(KERN_WARNING
"%s: fix this legacy no-device port driver!\n",
543 parport_proc_register(port
);
544 mutex_lock(®istration_lock
);
545 spin_lock_irq(&parportlist_lock
);
546 list_add_tail(&port
->list
, &portlist
);
547 for (i
= 1; i
< 3; i
++) {
548 struct parport
*slave
= port
->slaves
[i
-1];
550 list_add_tail(&slave
->list
, &portlist
);
552 spin_unlock_irq(&parportlist_lock
);
554 /* Let drivers know that new port(s) has arrived. */
555 attach_driver_chain (port
);
556 for (i
= 1; i
< 3; i
++) {
557 struct parport
*slave
= port
->slaves
[i
-1];
559 attach_driver_chain(slave
);
561 mutex_unlock(®istration_lock
);
563 EXPORT_SYMBOL(parport_announce_port
);
566 * parport_remove_port - deregister a parallel port
567 * @port: parallel port to deregister
569 * When a parallel port driver is forcibly unloaded, or a
570 * parallel port becomes inaccessible, the port driver must call
571 * this function in order to deal with device drivers that still
574 * The parport structure associated with the port has its
575 * operations structure replaced with one containing 'null'
576 * operations that return errors or just don't do anything.
578 * Any drivers that have registered themselves using
579 * parport_register_driver() are notified that the port is no
580 * longer accessible by having their detach() routines called
581 * with @port as the parameter.
584 void parport_remove_port(struct parport
*port
)
588 mutex_lock(®istration_lock
);
590 /* Spread the word. */
591 detach_driver_chain (port
);
593 #ifdef CONFIG_PARPORT_1284
594 /* Forget the IEEE1284.3 topology of the port. */
595 parport_daisy_fini(port
);
596 for (i
= 1; i
< 3; i
++) {
597 struct parport
*slave
= port
->slaves
[i
-1];
600 detach_driver_chain(slave
);
601 parport_daisy_fini(slave
);
605 port
->ops
= &dead_ops
;
606 spin_lock(&parportlist_lock
);
607 list_del_init(&port
->list
);
608 for (i
= 1; i
< 3; i
++) {
609 struct parport
*slave
= port
->slaves
[i
-1];
611 list_del_init(&slave
->list
);
613 spin_unlock(&parportlist_lock
);
615 mutex_unlock(®istration_lock
);
617 parport_proc_unregister(port
);
619 for (i
= 1; i
< 3; i
++) {
620 struct parport
*slave
= port
->slaves
[i
-1];
622 parport_put_port(slave
);
625 EXPORT_SYMBOL(parport_remove_port
);
628 * parport_register_device - register a device on a parallel port
629 * @port: port to which the device is attached
630 * @name: a name to refer to the device
631 * @pf: preemption callback
632 * @kf: kick callback (wake-up)
633 * @irq_func: interrupt handler
634 * @flags: registration flags
635 * @handle: data for callback functions
637 * This function, called by parallel port device drivers,
638 * declares that a device is connected to a port, and tells the
639 * system all it needs to know.
641 * The @name is allocated by the caller and must not be
642 * deallocated until the caller calls @parport_unregister_device
645 * The preemption callback function, @pf, is called when this
646 * device driver has claimed access to the port but another
647 * device driver wants to use it. It is given @handle as its
648 * parameter, and should return zero if it is willing for the
649 * system to release the port to another driver on its behalf.
650 * If it wants to keep control of the port it should return
651 * non-zero, and no action will be taken. It is good manners for
652 * the driver to try to release the port at the earliest
653 * opportunity after its preemption callback rejects a preemption
654 * attempt. Note that if a preemption callback is happy for
655 * preemption to go ahead, there is no need to release the port;
656 * it is done automatically. This function may not block, as it
657 * may be called from interrupt context. If the device driver
658 * does not support preemption, @pf can be %NULL.
660 * The wake-up ("kick") callback function, @kf, is called when
661 * the port is available to be claimed for exclusive access; that
662 * is, parport_claim() is guaranteed to succeed when called from
663 * inside the wake-up callback function. If the driver wants to
664 * claim the port it should do so; otherwise, it need not take
665 * any action. This function may not block, as it may be called
666 * from interrupt context. If the device driver does not want to
667 * be explicitly invited to claim the port in this way, @kf can
670 * The interrupt handler, @irq_func, is called when an interrupt
671 * arrives from the parallel port. Note that if a device driver
672 * wants to use interrupts it should use parport_enable_irq(),
673 * and can also check the irq member of the parport structure
674 * representing the port.
676 * The parallel port (lowlevel) driver is the one that has called
677 * request_irq() and whose interrupt handler is called first.
678 * This handler does whatever needs to be done to the hardware to
679 * acknowledge the interrupt (for PC-style ports there is nothing
680 * special to be done). It then tells the IEEE 1284 code about
681 * the interrupt, which may involve reacting to an IEEE 1284
682 * event depending on the current IEEE 1284 phase. After this,
683 * it calls @irq_func. Needless to say, @irq_func will be called
684 * from interrupt context, and may not block.
686 * The %PARPORT_DEV_EXCL flag is for preventing port sharing, and
687 * so should only be used when sharing the port with other device
688 * drivers is impossible and would lead to incorrect behaviour.
689 * Use it sparingly! Normally, @flags will be zero.
691 * This function returns a pointer to a structure that represents
692 * the device on the port, or %NULL if there is not enough memory
693 * to allocate space for that structure.
697 parport_register_device(struct parport
*port
, const char *name
,
698 int (*pf
)(void *), void (*kf
)(void *),
699 void (*irq_func
)(void *),
700 int flags
, void *handle
)
702 struct pardevice
*tmp
;
704 if (port
->physport
->flags
& PARPORT_FLAG_EXCL
) {
705 /* An exclusive device is registered. */
706 printk (KERN_DEBUG
"%s: no more devices allowed\n",
711 if (flags
& PARPORT_DEV_LURK
) {
713 printk(KERN_INFO
"%s: refused to register lurking device (%s) without callbacks\n", port
->name
, name
);
718 if (flags
& PARPORT_DEV_EXCL
) {
719 if (port
->physport
->devices
) {
721 * If a device is already registered and this new
722 * device wants exclusive access, then no need to
723 * continue as we can not grant exclusive access to
726 pr_err("%s: cannot grant exclusive access for device %s\n",
733 * We up our own module reference count, and that of the port
734 * on which a device is to be registered, to ensure that
735 * neither of us gets unloaded while we sleep in (e.g.)
738 if (!try_module_get(port
->ops
->owner
))
741 parport_get_port (port
);
743 tmp
= kmalloc(sizeof(struct pardevice
), GFP_KERNEL
);
745 printk(KERN_WARNING
"%s: memory squeeze, couldn't register %s.\n", port
->name
, name
);
749 tmp
->state
= kmalloc(sizeof(struct parport_state
), GFP_KERNEL
);
750 if (tmp
->state
== NULL
) {
751 printk(KERN_WARNING
"%s: memory squeeze, couldn't register %s.\n", port
->name
, name
);
752 goto out_free_pardevice
;
760 tmp
->private = handle
;
762 tmp
->irq_func
= irq_func
;
764 tmp
->timeout
= 5 * HZ
;
765 tmp
->devmodel
= false;
767 /* Chain this onto the list */
770 * This function must not run from an irq handler so we don' t need
771 * to clear irq on the local CPU. -arca
773 spin_lock(&port
->physport
->pardevice_lock
);
775 if (flags
& PARPORT_DEV_EXCL
) {
776 if (port
->physport
->devices
) {
777 spin_unlock (&port
->physport
->pardevice_lock
);
779 "%s: cannot grant exclusive access for device %s\n",
783 port
->flags
|= PARPORT_FLAG_EXCL
;
786 tmp
->next
= port
->physport
->devices
;
788 * Make sure that tmp->next is written before it's
789 * added to the list; see comments marked 'no locking
792 if (port
->physport
->devices
)
793 port
->physport
->devices
->prev
= tmp
;
794 port
->physport
->devices
= tmp
;
795 spin_unlock(&port
->physport
->pardevice_lock
);
797 init_waitqueue_head(&tmp
->wait_q
);
798 tmp
->timeslice
= parport_default_timeslice
;
799 tmp
->waitnext
= tmp
->waitprev
= NULL
;
802 * This has to be run as last thing since init_state may need other
803 * pardevice fields. -arca
805 port
->ops
->init_state(tmp
, tmp
->state
);
806 if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED
, &port
->devflags
)) {
807 port
->proc_device
= tmp
;
808 parport_device_proc_register(tmp
);
817 parport_put_port (port
);
818 module_put(port
->ops
->owner
);
822 EXPORT_SYMBOL(parport_register_device
);
824 static void free_pardevice(struct device
*dev
)
826 struct pardevice
*par_dev
= to_pardevice(dev
);
828 kfree(par_dev
->name
);
833 parport_register_dev_model(struct parport
*port
, const char *name
,
834 const struct pardev_cb
*par_dev_cb
, int id
)
836 struct pardevice
*par_dev
;
840 if (port
->physport
->flags
& PARPORT_FLAG_EXCL
) {
841 /* An exclusive device is registered. */
842 pr_err("%s: no more devices allowed\n", port
->name
);
846 if (par_dev_cb
->flags
& PARPORT_DEV_LURK
) {
847 if (!par_dev_cb
->preempt
|| !par_dev_cb
->wakeup
) {
848 pr_info("%s: refused to register lurking device (%s) without callbacks\n",
854 if (par_dev_cb
->flags
& PARPORT_DEV_EXCL
) {
855 if (port
->physport
->devices
) {
857 * If a device is already registered and this new
858 * device wants exclusive access, then no need to
859 * continue as we can not grant exclusive access to
862 pr_err("%s: cannot grant exclusive access for device %s\n",
868 if (!try_module_get(port
->ops
->owner
))
871 parport_get_port(port
);
873 par_dev
= kzalloc(sizeof(*par_dev
), GFP_KERNEL
);
877 par_dev
->state
= kzalloc(sizeof(*par_dev
->state
), GFP_KERNEL
);
879 goto err_put_par_dev
;
881 devname
= kstrdup(name
, GFP_KERNEL
);
883 goto err_free_par_dev
;
885 par_dev
->name
= devname
;
886 par_dev
->port
= port
;
888 par_dev
->preempt
= par_dev_cb
->preempt
;
889 par_dev
->wakeup
= par_dev_cb
->wakeup
;
890 par_dev
->private = par_dev_cb
->private;
891 par_dev
->flags
= par_dev_cb
->flags
;
892 par_dev
->irq_func
= par_dev_cb
->irq_func
;
893 par_dev
->waiting
= 0;
894 par_dev
->timeout
= 5 * HZ
;
896 par_dev
->dev
.parent
= &port
->bus_dev
;
897 par_dev
->dev
.bus
= &parport_bus_type
;
898 ret
= dev_set_name(&par_dev
->dev
, "%s.%d", devname
, id
);
900 goto err_free_devname
;
901 par_dev
->dev
.release
= free_pardevice
;
902 par_dev
->devmodel
= true;
903 ret
= device_register(&par_dev
->dev
);
905 put_device(&par_dev
->dev
);
909 /* Chain this onto the list */
910 par_dev
->prev
= NULL
;
912 * This function must not run from an irq handler so we don' t need
913 * to clear irq on the local CPU. -arca
915 spin_lock(&port
->physport
->pardevice_lock
);
917 if (par_dev_cb
->flags
& PARPORT_DEV_EXCL
) {
918 if (port
->physport
->devices
) {
919 spin_unlock(&port
->physport
->pardevice_lock
);
920 pr_debug("%s: cannot grant exclusive access for device %s\n",
922 device_unregister(&par_dev
->dev
);
925 port
->flags
|= PARPORT_FLAG_EXCL
;
928 par_dev
->next
= port
->physport
->devices
;
930 * Make sure that tmp->next is written before it's
931 * added to the list; see comments marked 'no locking
934 if (port
->physport
->devices
)
935 port
->physport
->devices
->prev
= par_dev
;
936 port
->physport
->devices
= par_dev
;
937 spin_unlock(&port
->physport
->pardevice_lock
);
939 init_waitqueue_head(&par_dev
->wait_q
);
940 par_dev
->timeslice
= parport_default_timeslice
;
941 par_dev
->waitnext
= NULL
;
942 par_dev
->waitprev
= NULL
;
945 * This has to be run as last thing since init_state may need other
946 * pardevice fields. -arca
948 port
->ops
->init_state(par_dev
, par_dev
->state
);
949 port
->proc_device
= par_dev
;
950 parport_device_proc_register(par_dev
);
957 kfree(par_dev
->state
);
959 if (!par_dev
->devmodel
)
962 parport_put_port(port
);
963 module_put(port
->ops
->owner
);
967 EXPORT_SYMBOL(parport_register_dev_model
);
970 * parport_unregister_device - deregister a device on a parallel port
971 * @dev: pointer to structure representing device
973 * This undoes the effect of parport_register_device().
976 void parport_unregister_device(struct pardevice
*dev
)
978 struct parport
*port
;
980 #ifdef PARPORT_PARANOID
982 printk(KERN_ERR
"parport_unregister_device: passed NULL\n");
987 port
= dev
->port
->physport
;
989 if (port
->proc_device
== dev
) {
990 port
->proc_device
= NULL
;
991 clear_bit(PARPORT_DEVPROC_REGISTERED
, &port
->devflags
);
992 parport_device_proc_unregister(dev
);
995 if (port
->cad
== dev
) {
996 printk(KERN_DEBUG
"%s: %s forgot to release port\n",
997 port
->name
, dev
->name
);
998 parport_release (dev
);
1001 spin_lock(&port
->pardevice_lock
);
1003 dev
->next
->prev
= dev
->prev
;
1005 dev
->prev
->next
= dev
->next
;
1007 port
->devices
= dev
->next
;
1009 if (dev
->flags
& PARPORT_DEV_EXCL
)
1010 port
->flags
&= ~PARPORT_FLAG_EXCL
;
1012 spin_unlock(&port
->pardevice_lock
);
1015 * Make sure we haven't left any pointers around in the wait
1018 spin_lock_irq(&port
->waitlist_lock
);
1019 if (dev
->waitprev
|| dev
->waitnext
|| port
->waithead
== dev
) {
1021 dev
->waitprev
->waitnext
= dev
->waitnext
;
1023 port
->waithead
= dev
->waitnext
;
1025 dev
->waitnext
->waitprev
= dev
->waitprev
;
1027 port
->waittail
= dev
->waitprev
;
1029 spin_unlock_irq(&port
->waitlist_lock
);
1033 device_unregister(&dev
->dev
);
1037 module_put(port
->ops
->owner
);
1038 parport_put_port (port
);
1040 EXPORT_SYMBOL(parport_unregister_device
);
1043 * parport_find_number - find a parallel port by number
1044 * @number: parallel port number
1046 * This returns the parallel port with the specified number, or
1047 * %NULL if there is none.
1049 * There is an implicit parport_get_port() done already; to throw
1050 * away the reference to the port that parport_find_number()
1051 * gives you, use parport_put_port().
1054 struct parport
*parport_find_number (int number
)
1056 struct parport
*port
, *result
= NULL
;
1058 if (list_empty(&portlist
))
1059 get_lowlevel_driver ();
1061 spin_lock (&parportlist_lock
);
1062 list_for_each_entry(port
, &portlist
, list
) {
1063 if (port
->number
== number
) {
1064 result
= parport_get_port (port
);
1068 spin_unlock (&parportlist_lock
);
1071 EXPORT_SYMBOL(parport_find_number
);
1074 * parport_find_base - find a parallel port by base address
1075 * @base: base I/O address
1077 * This returns the parallel port with the specified base
1078 * address, or %NULL if there is none.
1080 * There is an implicit parport_get_port() done already; to throw
1081 * away the reference to the port that parport_find_base()
1082 * gives you, use parport_put_port().
1085 struct parport
*parport_find_base (unsigned long base
)
1087 struct parport
*port
, *result
= NULL
;
1089 if (list_empty(&portlist
))
1090 get_lowlevel_driver ();
1092 spin_lock (&parportlist_lock
);
1093 list_for_each_entry(port
, &portlist
, list
) {
1094 if (port
->base
== base
) {
1095 result
= parport_get_port (port
);
1099 spin_unlock (&parportlist_lock
);
1102 EXPORT_SYMBOL(parport_find_base
);
1105 * parport_claim - claim access to a parallel port device
1106 * @dev: pointer to structure representing a device on the port
1108 * This function will not block and so can be used from interrupt
1109 * context. If parport_claim() succeeds in claiming access to
1110 * the port it returns zero and the port is available to use. It
1111 * may fail (returning non-zero) if the port is in use by another
1112 * driver and that driver is not willing to relinquish control of
1116 int parport_claim(struct pardevice
*dev
)
1118 struct pardevice
*oldcad
;
1119 struct parport
*port
= dev
->port
->physport
;
1120 unsigned long flags
;
1122 if (port
->cad
== dev
) {
1123 printk(KERN_INFO
"%s: %s already owner\n",
1124 dev
->port
->name
,dev
->name
);
1128 /* Preempt any current device */
1129 write_lock_irqsave (&port
->cad_lock
, flags
);
1130 if ((oldcad
= port
->cad
) != NULL
) {
1131 if (oldcad
->preempt
) {
1132 if (oldcad
->preempt(oldcad
->private))
1134 port
->ops
->save_state(port
, dev
->state
);
1138 if (port
->cad
!= oldcad
) {
1140 * I think we'll actually deadlock rather than
1141 * get here, but just in case..
1144 "%s: %s released port when preempted!\n",
1145 port
->name
, oldcad
->name
);
1151 /* Can't fail from now on, so mark ourselves as no longer waiting. */
1152 if (dev
->waiting
& 1) {
1155 /* Take ourselves out of the wait list again. */
1156 spin_lock_irq (&port
->waitlist_lock
);
1158 dev
->waitprev
->waitnext
= dev
->waitnext
;
1160 port
->waithead
= dev
->waitnext
;
1162 dev
->waitnext
->waitprev
= dev
->waitprev
;
1164 port
->waittail
= dev
->waitprev
;
1165 spin_unlock_irq (&port
->waitlist_lock
);
1166 dev
->waitprev
= dev
->waitnext
= NULL
;
1169 /* Now we do the change of devices */
1172 #ifdef CONFIG_PARPORT_1284
1173 /* If it's a mux port, select it. */
1174 if (dev
->port
->muxport
>= 0) {
1176 port
->muxsel
= dev
->port
->muxport
;
1179 /* If it's a daisy chain device, select it. */
1180 if (dev
->daisy
>= 0) {
1181 /* This could be lazier. */
1182 if (!parport_daisy_select (port
, dev
->daisy
,
1183 IEEE1284_MODE_COMPAT
))
1184 port
->daisy
= dev
->daisy
;
1186 #endif /* IEEE1284.3 support */
1188 /* Restore control registers */
1189 port
->ops
->restore_state(port
, dev
->state
);
1190 write_unlock_irqrestore(&port
->cad_lock
, flags
);
1191 dev
->time
= jiffies
;
1196 * If this is the first time we tried to claim the port, register an
1197 * interest. This is only allowed for devices sleeping in
1198 * parport_claim_or_block(), or those with a wakeup function.
1201 /* The cad_lock is still held for writing here */
1202 if (dev
->waiting
& 2 || dev
->wakeup
) {
1203 spin_lock (&port
->waitlist_lock
);
1204 if (test_and_set_bit(0, &dev
->waiting
) == 0) {
1205 /* First add ourselves to the end of the wait list. */
1206 dev
->waitnext
= NULL
;
1207 dev
->waitprev
= port
->waittail
;
1208 if (port
->waittail
) {
1209 port
->waittail
->waitnext
= dev
;
1210 port
->waittail
= dev
;
1212 port
->waithead
= port
->waittail
= dev
;
1214 spin_unlock (&port
->waitlist_lock
);
1216 write_unlock_irqrestore (&port
->cad_lock
, flags
);
1219 EXPORT_SYMBOL(parport_claim
);
1222 * parport_claim_or_block - claim access to a parallel port device
1223 * @dev: pointer to structure representing a device on the port
1225 * This behaves like parport_claim(), but will block if necessary
1226 * to wait for the port to be free. A return value of 1
1227 * indicates that it slept; 0 means that it succeeded without
1228 * needing to sleep. A negative error code indicates failure.
1231 int parport_claim_or_block(struct pardevice
*dev
)
1236 * Signal to parport_claim() that we can wait even without a
1241 /* Try to claim the port. If this fails, we need to sleep. */
1242 r
= parport_claim(dev
);
1244 #ifdef PARPORT_DEBUG_SHARING
1245 printk(KERN_DEBUG
"%s: parport_claim() returned -EAGAIN\n", dev
->name
);
1248 * FIXME!!! Use the proper locking for dev->waiting,
1249 * and make this use the "wait_event_interruptible()"
1250 * interfaces. The cli/sti that used to be here
1253 * See also parport_release()
1257 * If dev->waiting is clear now, an interrupt
1258 * gave us the port and we would deadlock if we slept.
1261 wait_event_interruptible(dev
->wait_q
,
1263 if (signal_pending (current
))
1268 #ifdef PARPORT_DEBUG_SHARING
1269 printk(KERN_DEBUG
"%s: didn't sleep in parport_claim_or_block()\n",
1274 #ifdef PARPORT_DEBUG_SHARING
1275 if (dev
->port
->physport
->cad
!= dev
)
1276 printk(KERN_DEBUG
"%s: exiting parport_claim_or_block but %s owns port!\n",
1277 dev
->name
, dev
->port
->physport
->cad
?
1278 dev
->port
->physport
->cad
->name
:"nobody");
1284 EXPORT_SYMBOL(parport_claim_or_block
);
1287 * parport_release - give up access to a parallel port device
1288 * @dev: pointer to structure representing parallel port device
1290 * This function cannot fail, but it should not be called without
1291 * the port claimed. Similarly, if the port is already claimed
1292 * you should not try claiming it again.
1295 void parport_release(struct pardevice
*dev
)
1297 struct parport
*port
= dev
->port
->physport
;
1298 struct pardevice
*pd
;
1299 unsigned long flags
;
1301 /* Make sure that dev is the current device */
1302 write_lock_irqsave(&port
->cad_lock
, flags
);
1303 if (port
->cad
!= dev
) {
1304 write_unlock_irqrestore (&port
->cad_lock
, flags
);
1305 printk(KERN_WARNING
"%s: %s tried to release parport when not owner\n",
1306 port
->name
, dev
->name
);
1310 #ifdef CONFIG_PARPORT_1284
1311 /* If this is on a mux port, deselect it. */
1312 if (dev
->port
->muxport
>= 0) {
1317 /* If this is a daisy device, deselect it. */
1318 if (dev
->daisy
>= 0) {
1319 parport_daisy_deselect_all (port
);
1325 write_unlock_irqrestore(&port
->cad_lock
, flags
);
1327 /* Save control registers */
1328 port
->ops
->save_state(port
, dev
->state
);
1331 * If anybody is waiting, find out who's been there longest and
1332 * then wake them up. (Note: no locking required)
1334 /* !!! LOCKING IS NEEDED HERE */
1335 for (pd
= port
->waithead
; pd
; pd
= pd
->waitnext
) {
1336 if (pd
->waiting
& 2) { /* sleeping in claim_or_block */
1338 if (waitqueue_active(&pd
->wait_q
))
1339 wake_up_interruptible(&pd
->wait_q
);
1341 } else if (pd
->wakeup
) {
1342 pd
->wakeup(pd
->private);
1343 if (dev
->port
->cad
) /* racy but no matter */
1346 printk(KERN_ERR
"%s: don't know how to wake %s\n", port
->name
, pd
->name
);
1351 * Nobody was waiting, so walk the list to see if anyone is
1352 * interested in being woken up. (Note: no locking required)
1354 /* !!! LOCKING IS NEEDED HERE */
1355 for (pd
= port
->devices
; (port
->cad
== NULL
) && pd
; pd
= pd
->next
) {
1356 if (pd
->wakeup
&& pd
!= dev
)
1357 pd
->wakeup(pd
->private);
1360 EXPORT_SYMBOL(parport_release
);
1362 irqreturn_t
parport_irq_handler(int irq
, void *dev_id
)
1364 struct parport
*port
= dev_id
;
1366 parport_generic_irq(port
);
1370 EXPORT_SYMBOL(parport_irq_handler
);
1372 MODULE_LICENSE("GPL");