blob: 510a9452429848d20abae91b47a9005aa95c4b8f [file] [log] [blame]
Len Brownc8f7a622006-07-09 17:22:28 -04001/*
2 * dock.c - ACPI dock station driver
3 *
4 * Copyright (C) 2006 Kristen Carlson Accardi <kristen.c.accardi@intel.com>
5 *
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or (at
11 * your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21 *
22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23 */
24
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/init.h>
28#include <linux/types.h>
29#include <linux/notifier.h>
30#include <acpi/acpi_bus.h>
31#include <acpi/acpi_drivers.h>
32
33#define ACPI_DOCK_DRIVER_NAME "ACPI Dock Station Driver"
34
35ACPI_MODULE_NAME("dock")
36MODULE_AUTHOR("Kristen Carlson Accardi");
37MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_NAME);
38MODULE_LICENSE("GPL");
39
40static struct atomic_notifier_head dock_notifier_list;
41
42struct dock_station {
43 acpi_handle handle;
44 unsigned long last_dock_time;
45 u32 flags;
46 spinlock_t dd_lock;
47 spinlock_t hp_lock;
48 struct list_head dependent_devices;
49 struct list_head hotplug_devices;
50};
51
52struct dock_dependent_device {
53 struct list_head list;
54 struct list_head hotplug_list;
55 acpi_handle handle;
56 acpi_notify_handler handler;
57 void *context;
58};
59
60#define DOCK_DOCKING 0x00000001
61#define DOCK_EVENT KOBJ_DOCK
62#define UNDOCK_EVENT KOBJ_UNDOCK
63
64static struct dock_station *dock_station;
65
66/*****************************************************************************
67 * Dock Dependent device functions *
68 *****************************************************************************/
69/**
70 * alloc_dock_dependent_device - allocate and init a dependent device
71 * @handle: the acpi_handle of the dependent device
72 *
73 * Allocate memory for a dependent device structure for a device referenced
74 * by the acpi handle
75 */
76static struct dock_dependent_device *
77alloc_dock_dependent_device(acpi_handle handle)
78{
79 struct dock_dependent_device *dd;
80
81 dd = kzalloc(sizeof(*dd), GFP_KERNEL);
82 if (dd) {
83 dd->handle = handle;
84 INIT_LIST_HEAD(&dd->list);
85 INIT_LIST_HEAD(&dd->hotplug_list);
86 }
87 return dd;
88}
89
90/**
91 * add_dock_dependent_device - associate a device with the dock station
92 * @ds: The dock station
93 * @dd: The dependent device
94 *
95 * Add the dependent device to the dock's dependent device list.
96 */
97static void
98add_dock_dependent_device(struct dock_station *ds,
99 struct dock_dependent_device *dd)
100{
101 spin_lock(&ds->dd_lock);
102 list_add_tail(&dd->list, &ds->dependent_devices);
103 spin_unlock(&ds->dd_lock);
104}
105
106/**
107 * dock_add_hotplug_device - associate a hotplug handler with the dock station
108 * @ds: The dock station
109 * @dd: The dependent device struct
110 *
111 * Add the dependent device to the dock's hotplug device list
112 */
113static void
114dock_add_hotplug_device(struct dock_station *ds,
115 struct dock_dependent_device *dd)
116{
117 spin_lock(&ds->hp_lock);
118 list_add_tail(&dd->hotplug_list, &ds->hotplug_devices);
119 spin_unlock(&ds->hp_lock);
120}
121
122/**
123 * dock_del_hotplug_device - remove a hotplug handler from the dock station
124 * @ds: The dock station
125 * @dd: the dependent device struct
126 *
127 * Delete the dependent device from the dock's hotplug device list
128 */
129static void
130dock_del_hotplug_device(struct dock_station *ds,
131 struct dock_dependent_device *dd)
132{
133 spin_lock(&ds->hp_lock);
134 list_del(&dd->hotplug_list);
135 spin_unlock(&ds->hp_lock);
136}
137
138/**
139 * find_dock_dependent_device - get a device dependent on this dock
140 * @ds: the dock station
141 * @handle: the acpi_handle of the device we want
142 *
143 * iterate over the dependent device list for this dock. If the
144 * dependent device matches the handle, return.
145 */
146static struct dock_dependent_device *
147find_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
148{
149 struct dock_dependent_device *dd;
150
151 spin_lock(&ds->dd_lock);
152 list_for_each_entry(dd, &ds->dependent_devices, list) {
153 if (handle == dd->handle) {
154 spin_unlock(&ds->dd_lock);
155 return dd;
156 }
157 }
158 spin_unlock(&ds->dd_lock);
159 return NULL;
160}
161
162/*****************************************************************************
163 * Dock functions *
164 *****************************************************************************/
165/**
166 * is_dock - see if a device is a dock station
167 * @handle: acpi handle of the device
168 *
169 * If an acpi object has a _DCK method, then it is by definition a dock
170 * station, so return true.
171 */
172static int is_dock(acpi_handle handle)
173{
174 acpi_status status;
175 acpi_handle tmp;
176
177 status = acpi_get_handle(handle, "_DCK", &tmp);
178 if (ACPI_FAILURE(status))
179 return 0;
180 return 1;
181}
182
183/**
184 * is_dock_device - see if a device is on a dock station
185 * @handle: acpi handle of the device
186 *
187 * If this device is either the dock station itself,
188 * or is a device dependent on the dock station, then it
189 * is a dock device
190 */
191int is_dock_device(acpi_handle handle)
192{
193 if (!dock_station)
194 return 0;
195
196 if (is_dock(handle) || find_dock_dependent_device(dock_station, handle))
197 return 1;
198
199 return 0;
200}
201
202EXPORT_SYMBOL_GPL(is_dock_device);
203
204/**
205 * dock_present - see if the dock station is present.
206 * @ds: the dock station
207 *
208 * execute the _STA method. note that present does not
209 * imply that we are docked.
210 */
211static int dock_present(struct dock_station *ds)
212{
213 unsigned long sta;
214 acpi_status status;
215
216 if (ds) {
217 status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
218 if (ACPI_SUCCESS(status) && sta)
219 return 1;
220 }
221 return 0;
222}
223
224
225
226/**
227 * dock_create_acpi_device - add new devices to acpi
228 * @handle - handle of the device to add
229 *
230 * This function will create a new acpi_device for the given
231 * handle if one does not exist already. This should cause
232 * acpi to scan for drivers for the given devices, and call
233 * matching driver's add routine.
234 *
235 * Returns a pointer to the acpi_device corresponding to the handle.
236 */
237static struct acpi_device * dock_create_acpi_device(acpi_handle handle)
238{
239 struct acpi_device *device = NULL;
240 struct acpi_device *parent_device;
241 acpi_handle parent;
242 int ret;
243
244 if (acpi_bus_get_device(handle, &device)) {
245 /*
246 * no device created for this object,
247 * so we should create one.
248 */
249 acpi_get_parent(handle, &parent);
250 if (acpi_bus_get_device(parent, &parent_device))
251 parent_device = NULL;
252
253 ret = acpi_bus_add(&device, parent_device, handle,
254 ACPI_BUS_TYPE_DEVICE);
255 if (ret) {
256 pr_debug("error adding bus, %x\n",
257 -ret);
258 return NULL;
259 }
260 }
261 return device;
262}
263
264/**
265 * dock_remove_acpi_device - remove the acpi_device struct from acpi
266 * @handle - the handle of the device to remove
267 *
268 * Tell acpi to remove the acpi_device. This should cause any loaded
269 * driver to have it's remove routine called.
270 */
271static void dock_remove_acpi_device(acpi_handle handle)
272{
273 struct acpi_device *device;
274 int ret;
275
276 if (!acpi_bus_get_device(handle, &device)) {
277 ret = acpi_bus_trim(device, 1);
278 if (ret)
279 pr_debug("error removing bus, %x\n", -ret);
280 }
281}
282
283
284/**
285 * hotplug_dock_devices - insert or remove devices on the dock station
286 * @ds: the dock station
287 * @event: either bus check or eject request
288 *
289 * Some devices on the dock station need to have drivers called
290 * to perform hotplug operations after a dock event has occurred.
291 * Traverse the list of dock devices that have registered a
292 * hotplug handler, and call the handler.
293 */
294static void hotplug_dock_devices(struct dock_station *ds, u32 event)
295{
296 struct dock_dependent_device *dd;
297
298 spin_lock(&ds->hp_lock);
299
300 /*
301 * First call driver specific hotplug functions
302 */
303 list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list) {
304 if (dd->handler)
305 dd->handler(dd->handle, event, dd->context);
306 }
307
308 /*
309 * Now make sure that an acpi_device is created for each
310 * dependent device, or removed if this is an eject request.
311 * This will cause acpi_drivers to be stopped/started if they
312 * exist
313 */
314 list_for_each_entry(dd, &ds->dependent_devices, list) {
315 if (event == ACPI_NOTIFY_EJECT_REQUEST)
316 dock_remove_acpi_device(dd->handle);
317 else
318 dock_create_acpi_device(dd->handle);
319 }
320 spin_unlock(&ds->hp_lock);
321}
322
323static void dock_event(struct dock_station *ds, u32 event, int num)
324{
325 struct acpi_device *device;
326
327 device = dock_create_acpi_device(ds->handle);
328 if (device)
329 kobject_uevent(&device->kobj, num);
330}
331
332/**
333 * eject_dock - respond to a dock eject request
334 * @ds: the dock station
335 *
336 * This is called after _DCK is called, to execute the dock station's
337 * _EJ0 method.
338 */
339static void eject_dock(struct dock_station *ds)
340{
341 struct acpi_object_list arg_list;
342 union acpi_object arg;
343 acpi_status status;
344 acpi_handle tmp;
345
346 /* all dock devices should have _EJ0, but check anyway */
347 status = acpi_get_handle(ds->handle, "_EJ0", &tmp);
348 if (ACPI_FAILURE(status)) {
349 pr_debug("No _EJ0 support for dock device\n");
350 return;
351 }
352
353 arg_list.count = 1;
354 arg_list.pointer = &arg;
355 arg.type = ACPI_TYPE_INTEGER;
356 arg.integer.value = 1;
357
358 if (ACPI_FAILURE(acpi_evaluate_object(ds->handle, "_EJ0",
359 &arg_list, NULL)))
360 pr_debug("Failed to evaluate _EJ0!\n");
361}
362
363/**
364 * handle_dock - handle a dock event
365 * @ds: the dock station
366 * @dock: to dock, or undock - that is the question
367 *
368 * Execute the _DCK method in response to an acpi event
369 */
370static void handle_dock(struct dock_station *ds, int dock)
371{
372 acpi_status status;
373 struct acpi_object_list arg_list;
374 union acpi_object arg;
375 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
376 struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL };
377 union acpi_object *obj;
378
379 acpi_get_name(ds->handle, ACPI_FULL_PATHNAME, &name_buffer);
380 obj = name_buffer.pointer;
381
382 printk(KERN_INFO PREFIX "%s\n", dock ? "docking" : "undocking");
383
384 /* _DCK method has one argument */
385 arg_list.count = 1;
386 arg_list.pointer = &arg;
387 arg.type = ACPI_TYPE_INTEGER;
388 arg.integer.value = dock;
389 status = acpi_evaluate_object(ds->handle, "_DCK", &arg_list, &buffer);
390 if (ACPI_FAILURE(status))
391 pr_debug("%s: failed to execute _DCK\n", obj->string.pointer);
392 kfree(buffer.pointer);
393 kfree(name_buffer.pointer);
394}
395
396static inline void dock(struct dock_station *ds)
397{
398 handle_dock(ds, 1);
399}
400
401static inline void undock(struct dock_station *ds)
402{
403 handle_dock(ds, 0);
404}
405
406static inline void begin_dock(struct dock_station *ds)
407{
408 ds->flags |= DOCK_DOCKING;
409}
410
411static inline void complete_dock(struct dock_station *ds)
412{
413 ds->flags &= ~(DOCK_DOCKING);
414 ds->last_dock_time = jiffies;
415}
416
417/**
418 * dock_in_progress - see if we are in the middle of handling a dock event
419 * @ds: the dock station
420 *
421 * Sometimes while docking, false dock events can be sent to the driver
422 * because good connections aren't made or some other reason. Ignore these
423 * if we are in the middle of doing something.
424 */
425static int dock_in_progress(struct dock_station *ds)
426{
427 if ((ds->flags & DOCK_DOCKING) ||
428 time_before(jiffies, (ds->last_dock_time + HZ)))
429 return 1;
430 return 0;
431}
432
433/**
434 * register_dock_notifier - add yourself to the dock notifier list
435 * @nb: the callers notifier block
436 *
437 * If a driver wishes to be notified about dock events, they can
438 * use this function to put a notifier block on the dock notifier list.
439 * this notifier call chain will be called after a dock event, but
440 * before hotplugging any new devices.
441 */
442int register_dock_notifier(struct notifier_block *nb)
443{
444 return atomic_notifier_chain_register(&dock_notifier_list, nb);
445}
446
447EXPORT_SYMBOL_GPL(register_dock_notifier);
448
449/**
450 * unregister_dock_notifier - remove yourself from the dock notifier list
451 * @nb: the callers notifier block
452 */
453void unregister_dock_notifier(struct notifier_block *nb)
454{
455 atomic_notifier_chain_unregister(&dock_notifier_list, nb);
456}
457
458EXPORT_SYMBOL_GPL(unregister_dock_notifier);
459
460/**
461 * register_hotplug_dock_device - register a hotplug function
462 * @handle: the handle of the device
463 * @handler: the acpi_notifier_handler to call after docking
464 * @context: device specific data
465 *
466 * If a driver would like to perform a hotplug operation after a dock
467 * event, they can register an acpi_notifiy_handler to be called by
468 * the dock driver after _DCK is executed.
469 */
470int
471register_hotplug_dock_device(acpi_handle handle, acpi_notify_handler handler,
472 void *context)
473{
474 struct dock_dependent_device *dd;
475
476 if (!dock_station)
477 return -ENODEV;
478
479 /*
480 * make sure this handle is for a device dependent on the dock,
481 * this would include the dock station itself
482 */
483 dd = find_dock_dependent_device(dock_station, handle);
484 if (dd) {
485 dd->handler = handler;
486 dd->context = context;
487 dock_add_hotplug_device(dock_station, dd);
488 return 0;
489 }
490
491 return -EINVAL;
492}
493
494EXPORT_SYMBOL_GPL(register_hotplug_dock_device);
495
496/**
497 * unregister_hotplug_dock_device - remove yourself from the hotplug list
498 * @handle: the acpi handle of the device
499 */
500void unregister_hotplug_dock_device(acpi_handle handle)
501{
502 struct dock_dependent_device *dd;
503
504 if (!dock_station)
505 return;
506
507 dd = find_dock_dependent_device(dock_station, handle);
508 if (dd)
509 dock_del_hotplug_device(dock_station, dd);
510}
511
512EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device);
513
514/**
515 * dock_notify - act upon an acpi dock notification
516 * @handle: the dock station handle
517 * @event: the acpi event
518 * @data: our driver data struct
519 *
520 * If we are notified to dock, then check to see if the dock is
521 * present and then dock. Notify all drivers of the dock event,
522 * and then hotplug and devices that may need hotplugging. For undock
523 * check to make sure the dock device is still present, then undock
524 * and hotremove all the devices that may need removing.
525 */
526static void dock_notify(acpi_handle handle, u32 event, void *data)
527{
528 struct dock_station *ds = (struct dock_station *)data;
529
530 switch (event) {
531 case ACPI_NOTIFY_BUS_CHECK:
532 if (!dock_in_progress(ds) && dock_present(ds)) {
533 begin_dock(ds);
534 dock(ds);
535 if (!dock_present(ds)) {
536 printk(KERN_ERR PREFIX "Unable to dock!\n");
537 break;
538 }
539 atomic_notifier_call_chain(&dock_notifier_list,
540 event, NULL);
541 hotplug_dock_devices(ds, event);
542 complete_dock(ds);
543 dock_event(ds, event, DOCK_EVENT);
544 }
545 break;
546 case ACPI_NOTIFY_DEVICE_CHECK:
547 /*
548 * According to acpi spec 3.0a, if a DEVICE_CHECK notification
549 * is sent and _DCK is present, it is assumed to mean an
550 * undock request. This notify routine will only be called
551 * for objects defining _DCK, so we will fall through to eject
552 * request here. However, we will pass an eject request through
553 * to the driver who wish to hotplug.
554 */
555 case ACPI_NOTIFY_EJECT_REQUEST:
556 if (!dock_in_progress(ds) && dock_present(ds)) {
557 /*
558 * here we need to generate the undock
559 * event prior to actually doing the undock
560 * so that the device struct still exists.
561 */
562 dock_event(ds, event, UNDOCK_EVENT);
563 hotplug_dock_devices(ds, ACPI_NOTIFY_EJECT_REQUEST);
564 undock(ds);
565 eject_dock(ds);
566 if (dock_present(ds))
567 printk(KERN_ERR PREFIX "Unable to undock!\n");
568 }
569 break;
570 default:
571 printk(KERN_ERR PREFIX "Unknown dock event %d\n", event);
572 }
573}
574
575/**
576 * find_dock_devices - find devices on the dock station
577 * @handle: the handle of the device we are examining
578 * @lvl: unused
579 * @context: the dock station private data
580 * @rv: unused
581 *
582 * This function is called by acpi_walk_namespace. It will
583 * check to see if an object has an _EJD method. If it does, then it
584 * will see if it is dependent on the dock station.
585 */
586static acpi_status
587find_dock_devices(acpi_handle handle, u32 lvl, void *context, void **rv)
588{
589 acpi_status status;
590 acpi_handle tmp;
591 struct dock_station *ds = (struct dock_station *)context;
592 struct dock_dependent_device *dd;
593
594 status = acpi_bus_get_ejd(handle, &tmp);
595 if (ACPI_FAILURE(status))
596 return AE_OK;
597
598 if (tmp == ds->handle) {
599 dd = alloc_dock_dependent_device(handle);
600 if (dd)
601 add_dock_dependent_device(ds, dd);
602 }
603
604 return AE_OK;
605}
606
607/**
608 * dock_add - add a new dock station
609 * @handle: the dock station handle
610 *
611 * allocated and initialize a new dock station device. Find all devices
612 * that are on the dock station, and register for dock event notifications.
613 */
614static int dock_add(acpi_handle handle)
615{
616 int ret;
617 acpi_status status;
618 struct dock_dependent_device *dd;
619
620 /* allocate & initialize the dock_station private data */
621 dock_station = kzalloc(sizeof(*dock_station), GFP_KERNEL);
622 if (!dock_station)
623 return -ENOMEM;
624 dock_station->handle = handle;
625 dock_station->last_dock_time = jiffies - HZ;
626 INIT_LIST_HEAD(&dock_station->dependent_devices);
627 INIT_LIST_HEAD(&dock_station->hotplug_devices);
628 spin_lock_init(&dock_station->dd_lock);
629 spin_lock_init(&dock_station->hp_lock);
630
631 /* Find dependent devices */
632 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
633 ACPI_UINT32_MAX, find_dock_devices, dock_station,
634 NULL);
635
636 /* add the dock station as a device dependent on itself */
637 dd = alloc_dock_dependent_device(handle);
638 if (!dd) {
639 kfree(dock_station);
640 return -ENOMEM;
641 }
642 add_dock_dependent_device(dock_station, dd);
643
644 /* register for dock events */
645 status = acpi_install_notify_handler(dock_station->handle,
646 ACPI_SYSTEM_NOTIFY,
647 dock_notify, dock_station);
648
649 if (ACPI_FAILURE(status)) {
650 printk(KERN_ERR PREFIX "Error installing notify handler\n");
651 ret = -ENODEV;
652 goto dock_add_err;
653 }
654
655 printk(KERN_INFO PREFIX "%s \n", ACPI_DOCK_DRIVER_NAME);
656
657 return 0;
658
659dock_add_err:
660 kfree(dock_station);
661 kfree(dd);
662 return ret;
663}
664
665/**
666 * dock_remove - free up resources related to the dock station
667 */
668static int dock_remove(void)
669{
670 struct dock_dependent_device *dd, *tmp;
671 acpi_status status;
672
673 if (!dock_station)
674 return 0;
675
676 /* remove dependent devices */
677 list_for_each_entry_safe(dd, tmp, &dock_station->dependent_devices,
678 list)
679 kfree(dd);
680
681 /* remove dock notify handler */
682 status = acpi_remove_notify_handler(dock_station->handle,
683 ACPI_SYSTEM_NOTIFY,
684 dock_notify);
685 if (ACPI_FAILURE(status))
686 printk(KERN_ERR "Error removing notify handler\n");
687
688 /* free dock station memory */
689 kfree(dock_station);
690 return 0;
691}
692
693/**
694 * find_dock - look for a dock station
695 * @handle: acpi handle of a device
696 * @lvl: unused
697 * @context: counter of dock stations found
698 * @rv: unused
699 *
700 * This is called by acpi_walk_namespace to look for dock stations.
701 */
702static acpi_status
703find_dock(acpi_handle handle, u32 lvl, void *context, void **rv)
704{
705 int *count = (int *)context;
706 acpi_status status = AE_OK;
707
708 if (is_dock(handle)) {
709 if (dock_add(handle) >= 0) {
710 (*count)++;
711 status = AE_CTRL_TERMINATE;
712 }
713 }
714 return status;
715}
716
717static int __init dock_init(void)
718{
719 int num = 0;
720
721 dock_station = NULL;
722
723 /* look for a dock station */
724 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
725 ACPI_UINT32_MAX, find_dock, &num, NULL);
726
727 if (!num)
728 return -ENODEV;
729
730 return 0;
731}
732
733static void __exit dock_exit(void)
734{
735 dock_remove();
736}
737
738postcore_initcall(dock_init);
739module_exit(dock_exit);