ia64/linux-2.6.18-xen.hg

view drivers/acpi/dock.c @ 912:dd42cdb0ab89

[IA64] Build blktap2 driver by default in x86 builds.

add CONFIG_XEN_BLKDEV_TAP2=y to buildconfigs/linux-defconfig_xen_ia64.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Isaku Yamahata <yamahata@valinux.co.jp>
date Mon Jun 29 12:09:16 2009 +0900 (2009-06-29)
parents 831230e53067
children
line source
1 /*
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 */
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>
33 #define ACPI_DOCK_DRIVER_NAME "ACPI Dock Station Driver"
35 ACPI_MODULE_NAME("dock")
36 MODULE_AUTHOR("Kristen Carlson Accardi");
37 MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_NAME);
38 MODULE_LICENSE("GPL");
40 static struct atomic_notifier_head dock_notifier_list;
42 struct 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 };
52 struct 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 };
60 #define DOCK_DOCKING 0x00000001
61 #define DOCK_EVENT 3
62 #define UNDOCK_EVENT 2
64 static struct dock_station *dock_station;
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 */
76 static struct dock_dependent_device *
77 alloc_dock_dependent_device(acpi_handle handle)
78 {
79 struct dock_dependent_device *dd;
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 }
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 */
97 static void
98 add_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 }
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 */
113 static void
114 dock_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 }
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 */
129 static void
130 dock_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 }
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 */
146 static struct dock_dependent_device *
147 find_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
148 {
149 struct dock_dependent_device *dd;
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 }
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 */
172 static int is_dock(acpi_handle handle)
173 {
174 acpi_status status;
175 acpi_handle tmp;
177 status = acpi_get_handle(handle, "_DCK", &tmp);
178 if (ACPI_FAILURE(status))
179 return 0;
180 return 1;
181 }
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 */
191 int is_dock_device(acpi_handle handle)
192 {
193 if (!dock_station)
194 return 0;
196 if (is_dock(handle) || find_dock_dependent_device(dock_station, handle))
197 return 1;
199 return 0;
200 }
202 EXPORT_SYMBOL_GPL(is_dock_device);
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 */
211 static int dock_present(struct dock_station *ds)
212 {
213 unsigned long sta;
214 acpi_status status;
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 }
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 */
237 static 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;
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;
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 }
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 */
271 static void dock_remove_acpi_device(acpi_handle handle)
272 {
273 struct acpi_device *device;
274 int ret;
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 }
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 */
294 static void hotplug_dock_devices(struct dock_station *ds, u32 event)
295 {
296 struct dock_dependent_device *dd;
298 spin_lock(&ds->hp_lock);
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 }
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 }
323 static void dock_event(struct dock_station *ds, u32 event, int num)
324 {
325 /*
326 * we don't do events until someone tells me that
327 * they would like to have them.
328 */
329 }
331 /**
332 * eject_dock - respond to a dock eject request
333 * @ds: the dock station
334 *
335 * This is called after _DCK is called, to execute the dock station's
336 * _EJ0 method.
337 */
338 static void eject_dock(struct dock_station *ds)
339 {
340 struct acpi_object_list arg_list;
341 union acpi_object arg;
342 acpi_status status;
343 acpi_handle tmp;
345 /* all dock devices should have _EJ0, but check anyway */
346 status = acpi_get_handle(ds->handle, "_EJ0", &tmp);
347 if (ACPI_FAILURE(status)) {
348 pr_debug("No _EJ0 support for dock device\n");
349 return;
350 }
352 arg_list.count = 1;
353 arg_list.pointer = &arg;
354 arg.type = ACPI_TYPE_INTEGER;
355 arg.integer.value = 1;
357 if (ACPI_FAILURE(acpi_evaluate_object(ds->handle, "_EJ0",
358 &arg_list, NULL)))
359 pr_debug("Failed to evaluate _EJ0!\n");
360 }
362 /**
363 * handle_dock - handle a dock event
364 * @ds: the dock station
365 * @dock: to dock, or undock - that is the question
366 *
367 * Execute the _DCK method in response to an acpi event
368 */
369 static void handle_dock(struct dock_station *ds, int dock)
370 {
371 acpi_status status;
372 struct acpi_object_list arg_list;
373 union acpi_object arg;
374 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
375 struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL };
376 union acpi_object *obj;
378 acpi_get_name(ds->handle, ACPI_FULL_PATHNAME, &name_buffer);
379 obj = name_buffer.pointer;
381 printk(KERN_INFO PREFIX "%s\n", dock ? "docking" : "undocking");
383 /* _DCK method has one argument */
384 arg_list.count = 1;
385 arg_list.pointer = &arg;
386 arg.type = ACPI_TYPE_INTEGER;
387 arg.integer.value = dock;
388 status = acpi_evaluate_object(ds->handle, "_DCK", &arg_list, &buffer);
389 if (ACPI_FAILURE(status))
390 pr_debug("%s: failed to execute _DCK\n", obj->string.pointer);
391 kfree(buffer.pointer);
392 kfree(name_buffer.pointer);
393 }
395 static inline void dock(struct dock_station *ds)
396 {
397 handle_dock(ds, 1);
398 }
400 static inline void undock(struct dock_station *ds)
401 {
402 handle_dock(ds, 0);
403 }
405 static inline void begin_dock(struct dock_station *ds)
406 {
407 ds->flags |= DOCK_DOCKING;
408 }
410 static inline void complete_dock(struct dock_station *ds)
411 {
412 ds->flags &= ~(DOCK_DOCKING);
413 ds->last_dock_time = jiffies;
414 }
416 /**
417 * dock_in_progress - see if we are in the middle of handling a dock event
418 * @ds: the dock station
419 *
420 * Sometimes while docking, false dock events can be sent to the driver
421 * because good connections aren't made or some other reason. Ignore these
422 * if we are in the middle of doing something.
423 */
424 static int dock_in_progress(struct dock_station *ds)
425 {
426 if ((ds->flags & DOCK_DOCKING) ||
427 time_before(jiffies, (ds->last_dock_time + HZ)))
428 return 1;
429 return 0;
430 }
432 /**
433 * register_dock_notifier - add yourself to the dock notifier list
434 * @nb: the callers notifier block
435 *
436 * If a driver wishes to be notified about dock events, they can
437 * use this function to put a notifier block on the dock notifier list.
438 * this notifier call chain will be called after a dock event, but
439 * before hotplugging any new devices.
440 */
441 int register_dock_notifier(struct notifier_block *nb)
442 {
443 return atomic_notifier_chain_register(&dock_notifier_list, nb);
444 }
446 EXPORT_SYMBOL_GPL(register_dock_notifier);
448 /**
449 * unregister_dock_notifier - remove yourself from the dock notifier list
450 * @nb: the callers notifier block
451 */
452 void unregister_dock_notifier(struct notifier_block *nb)
453 {
454 atomic_notifier_chain_unregister(&dock_notifier_list, nb);
455 }
457 EXPORT_SYMBOL_GPL(unregister_dock_notifier);
459 /**
460 * register_hotplug_dock_device - register a hotplug function
461 * @handle: the handle of the device
462 * @handler: the acpi_notifier_handler to call after docking
463 * @context: device specific data
464 *
465 * If a driver would like to perform a hotplug operation after a dock
466 * event, they can register an acpi_notifiy_handler to be called by
467 * the dock driver after _DCK is executed.
468 */
469 int
470 register_hotplug_dock_device(acpi_handle handle, acpi_notify_handler handler,
471 void *context)
472 {
473 struct dock_dependent_device *dd;
475 if (!dock_station)
476 return -ENODEV;
478 /*
479 * make sure this handle is for a device dependent on the dock,
480 * this would include the dock station itself
481 */
482 dd = find_dock_dependent_device(dock_station, handle);
483 if (dd) {
484 dd->handler = handler;
485 dd->context = context;
486 dock_add_hotplug_device(dock_station, dd);
487 return 0;
488 }
490 return -EINVAL;
491 }
493 EXPORT_SYMBOL_GPL(register_hotplug_dock_device);
495 /**
496 * unregister_hotplug_dock_device - remove yourself from the hotplug list
497 * @handle: the acpi handle of the device
498 */
499 void unregister_hotplug_dock_device(acpi_handle handle)
500 {
501 struct dock_dependent_device *dd;
503 if (!dock_station)
504 return;
506 dd = find_dock_dependent_device(dock_station, handle);
507 if (dd)
508 dock_del_hotplug_device(dock_station, dd);
509 }
511 EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device);
513 /**
514 * dock_notify - act upon an acpi dock notification
515 * @handle: the dock station handle
516 * @event: the acpi event
517 * @data: our driver data struct
518 *
519 * If we are notified to dock, then check to see if the dock is
520 * present and then dock. Notify all drivers of the dock event,
521 * and then hotplug and devices that may need hotplugging. For undock
522 * check to make sure the dock device is still present, then undock
523 * and hotremove all the devices that may need removing.
524 */
525 static void dock_notify(acpi_handle handle, u32 event, void *data)
526 {
527 struct dock_station *ds = (struct dock_station *)data;
529 switch (event) {
530 case ACPI_NOTIFY_BUS_CHECK:
531 if (!dock_in_progress(ds) && dock_present(ds)) {
532 begin_dock(ds);
533 dock(ds);
534 if (!dock_present(ds)) {
535 printk(KERN_ERR PREFIX "Unable to dock!\n");
536 break;
537 }
538 atomic_notifier_call_chain(&dock_notifier_list,
539 event, NULL);
540 hotplug_dock_devices(ds, event);
541 complete_dock(ds);
542 dock_event(ds, event, DOCK_EVENT);
543 }
544 break;
545 case ACPI_NOTIFY_DEVICE_CHECK:
546 /*
547 * According to acpi spec 3.0a, if a DEVICE_CHECK notification
548 * is sent and _DCK is present, it is assumed to mean an
549 * undock request. This notify routine will only be called
550 * for objects defining _DCK, so we will fall through to eject
551 * request here. However, we will pass an eject request through
552 * to the driver who wish to hotplug.
553 */
554 case ACPI_NOTIFY_EJECT_REQUEST:
555 if (!dock_in_progress(ds) && dock_present(ds)) {
556 /*
557 * here we need to generate the undock
558 * event prior to actually doing the undock
559 * so that the device struct still exists.
560 */
561 dock_event(ds, event, UNDOCK_EVENT);
562 hotplug_dock_devices(ds, ACPI_NOTIFY_EJECT_REQUEST);
563 undock(ds);
564 eject_dock(ds);
565 if (dock_present(ds))
566 printk(KERN_ERR PREFIX "Unable to undock!\n");
567 }
568 break;
569 default:
570 printk(KERN_ERR PREFIX "Unknown dock event %d\n", event);
571 }
572 }
574 /**
575 * find_dock_devices - find devices on the dock station
576 * @handle: the handle of the device we are examining
577 * @lvl: unused
578 * @context: the dock station private data
579 * @rv: unused
580 *
581 * This function is called by acpi_walk_namespace. It will
582 * check to see if an object has an _EJD method. If it does, then it
583 * will see if it is dependent on the dock station.
584 */
585 static acpi_status
586 find_dock_devices(acpi_handle handle, u32 lvl, void *context, void **rv)
587 {
588 acpi_status status;
589 acpi_handle tmp;
590 struct dock_station *ds = (struct dock_station *)context;
591 struct dock_dependent_device *dd;
593 status = acpi_bus_get_ejd(handle, &tmp);
594 if (ACPI_FAILURE(status))
595 return AE_OK;
597 if (tmp == ds->handle) {
598 dd = alloc_dock_dependent_device(handle);
599 if (dd)
600 add_dock_dependent_device(ds, dd);
601 }
603 return AE_OK;
604 }
606 /**
607 * dock_add - add a new dock station
608 * @handle: the dock station handle
609 *
610 * allocated and initialize a new dock station device. Find all devices
611 * that are on the dock station, and register for dock event notifications.
612 */
613 static int dock_add(acpi_handle handle)
614 {
615 int ret;
616 acpi_status status;
617 struct dock_dependent_device *dd;
619 /* allocate & initialize the dock_station private data */
620 dock_station = kzalloc(sizeof(*dock_station), GFP_KERNEL);
621 if (!dock_station)
622 return -ENOMEM;
623 dock_station->handle = handle;
624 dock_station->last_dock_time = jiffies - HZ;
625 INIT_LIST_HEAD(&dock_station->dependent_devices);
626 INIT_LIST_HEAD(&dock_station->hotplug_devices);
627 spin_lock_init(&dock_station->dd_lock);
628 spin_lock_init(&dock_station->hp_lock);
629 ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);
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);
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);
644 /* register for dock events */
645 status = acpi_install_notify_handler(dock_station->handle,
646 ACPI_SYSTEM_NOTIFY,
647 dock_notify, dock_station);
649 if (ACPI_FAILURE(status)) {
650 printk(KERN_ERR PREFIX "Error installing notify handler\n");
651 ret = -ENODEV;
652 goto dock_add_err;
653 }
655 printk(KERN_INFO PREFIX "%s \n", ACPI_DOCK_DRIVER_NAME);
657 return 0;
659 dock_add_err:
660 kfree(dock_station);
661 kfree(dd);
662 return ret;
663 }
665 /**
666 * dock_remove - free up resources related to the dock station
667 */
668 static int dock_remove(void)
669 {
670 struct dock_dependent_device *dd, *tmp;
671 acpi_status status;
673 if (!dock_station)
674 return 0;
676 /* remove dependent devices */
677 list_for_each_entry_safe(dd, tmp, &dock_station->dependent_devices,
678 list)
679 kfree(dd);
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");
688 /* free dock station memory */
689 kfree(dock_station);
690 return 0;
691 }
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 */
702 static acpi_status
703 find_dock(acpi_handle handle, u32 lvl, void *context, void **rv)
704 {
705 int *count = (int *)context;
706 acpi_status status = AE_OK;
708 if (is_dock(handle)) {
709 if (dock_add(handle) >= 0) {
710 (*count)++;
711 status = AE_CTRL_TERMINATE;
712 }
713 }
714 return status;
715 }
717 static int __init dock_init(void)
718 {
719 int num = 0;
721 dock_station = NULL;
723 /* look for a dock station */
724 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
725 ACPI_UINT32_MAX, find_dock, &num, NULL);
727 if (!num)
728 return -ENODEV;
730 return 0;
731 }
733 static void __exit dock_exit(void)
734 {
735 dock_remove();
736 }
738 postcore_initcall(dock_init);
739 module_exit(dock_exit);