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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 */
24
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/slab.h>
28#include <linux/init.h>
29#include <linux/types.h>
30#include <linux/notifier.h>
31#include <linux/platform_device.h>
32#include <linux/jiffies.h>
33#include <linux/stddef.h>
34#include <acpi/acpi_bus.h>
35#include <acpi/acpi_drivers.h>
36
37#define PREFIX "ACPI: "
38
39#define ACPI_DOCK_DRIVER_DESCRIPTION "ACPI Dock Station Driver"
40
41ACPI_MODULE_NAME("dock");
42MODULE_AUTHOR("Kristen Carlson Accardi");
43MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_DESCRIPTION);
44MODULE_LICENSE("GPL");
45
46static int immediate_undock = 1;
47module_param(immediate_undock, bool, 0644);
48MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
49	"undock immediately when the undock button is pressed, 0 will cause"
50	" the driver to wait for userspace to write the undock sysfs file "
51	" before undocking");
52
53static struct atomic_notifier_head dock_notifier_list;
54
55static const struct acpi_device_id dock_device_ids[] = {
56	{"LNXDOCK", 0},
57	{"", 0},
58};
59MODULE_DEVICE_TABLE(acpi, dock_device_ids);
60
61struct dock_station {
62	acpi_handle handle;
63	unsigned long last_dock_time;
64	u32 flags;
65	spinlock_t dd_lock;
66	struct mutex hp_lock;
67	struct list_head dependent_devices;
68	struct list_head hotplug_devices;
69
70	struct list_head sibling;
71	struct platform_device *dock_device;
72};
73static LIST_HEAD(dock_stations);
74static int dock_station_count;
75
76struct dock_dependent_device {
77	struct list_head list;
78	struct list_head hotplug_list;
79	acpi_handle handle;
80	struct acpi_dock_ops *ops;
81	void *context;
82};
83
84#define DOCK_DOCKING	0x00000001
85#define DOCK_UNDOCKING  0x00000002
86#define DOCK_IS_DOCK	0x00000010
87#define DOCK_IS_ATA	0x00000020
88#define DOCK_IS_BAT	0x00000040
89#define DOCK_EVENT	3
90#define UNDOCK_EVENT	2
91
92/*****************************************************************************
93 *                         Dock Dependent device functions                   *
94 *****************************************************************************/
95/**
96 * add_dock_dependent_device - associate a device with the dock station
97 * @ds: The dock station
98 * @handle: handle of the dependent device
99 *
100 * Add the dependent device to the dock's dependent device list.
101 */
102static int
103add_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
104{
105	struct dock_dependent_device *dd;
106
107	dd = kzalloc(sizeof(*dd), GFP_KERNEL);
108	if (!dd)
109		return -ENOMEM;
110
111	dd->handle = handle;
112	INIT_LIST_HEAD(&dd->list);
113	INIT_LIST_HEAD(&dd->hotplug_list);
114
115	spin_lock(&ds->dd_lock);
116	list_add_tail(&dd->list, &ds->dependent_devices);
117	spin_unlock(&ds->dd_lock);
118
119	return 0;
120}
121
122/**
123 * dock_add_hotplug_device - associate a hotplug handler with the dock station
124 * @ds: The dock station
125 * @dd: The dependent device struct
126 *
127 * Add the dependent device to the dock's hotplug device list
128 */
129static void
130dock_add_hotplug_device(struct dock_station *ds,
131			struct dock_dependent_device *dd)
132{
133	mutex_lock(&ds->hp_lock);
134	list_add_tail(&dd->hotplug_list, &ds->hotplug_devices);
135	mutex_unlock(&ds->hp_lock);
136}
137
138/**
139 * dock_del_hotplug_device - remove a hotplug handler from the dock station
140 * @ds: The dock station
141 * @dd: the dependent device struct
142 *
143 * Delete the dependent device from the dock's hotplug device list
144 */
145static void
146dock_del_hotplug_device(struct dock_station *ds,
147			struct dock_dependent_device *dd)
148{
149	mutex_lock(&ds->hp_lock);
150	list_del(&dd->hotplug_list);
151	mutex_unlock(&ds->hp_lock);
152}
153
154/**
155 * find_dock_dependent_device - get a device dependent on this dock
156 * @ds: the dock station
157 * @handle: the acpi_handle of the device we want
158 *
159 * iterate over the dependent device list for this dock.  If the
160 * dependent device matches the handle, return.
161 */
162static struct dock_dependent_device *
163find_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
164{
165	struct dock_dependent_device *dd;
166
167	spin_lock(&ds->dd_lock);
168	list_for_each_entry(dd, &ds->dependent_devices, list) {
169		if (handle == dd->handle) {
170			spin_unlock(&ds->dd_lock);
171			return dd;
172		}
173	}
174	spin_unlock(&ds->dd_lock);
175	return NULL;
176}
177
178/*****************************************************************************
179 *                         Dock functions                                    *
180 *****************************************************************************/
181/**
182 * is_dock - see if a device is a dock station
183 * @handle: acpi handle of the device
184 *
185 * If an acpi object has a _DCK method, then it is by definition a dock
186 * station, so return true.
187 */
188static int is_dock(acpi_handle handle)
189{
190	acpi_status status;
191	acpi_handle tmp;
192
193	status = acpi_get_handle(handle, "_DCK", &tmp);
194	if (ACPI_FAILURE(status))
195		return 0;
196	return 1;
197}
198
199static int is_ejectable(acpi_handle handle)
200{
201	acpi_status status;
202	acpi_handle tmp;
203
204	status = acpi_get_handle(handle, "_EJ0", &tmp);
205	if (ACPI_FAILURE(status))
206		return 0;
207	return 1;
208}
209
210static int is_ata(acpi_handle handle)
211{
212	acpi_handle tmp;
213
214	if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
215	   (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
216	   (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
217	   (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
218		return 1;
219
220	return 0;
221}
222
223static int is_battery(acpi_handle handle)
224{
225	struct acpi_device_info *info;
226	int ret = 1;
227
228	if (!ACPI_SUCCESS(acpi_get_object_info(handle, &info)))
229		return 0;
230	if (!(info->valid & ACPI_VALID_HID))
231		ret = 0;
232	else
233		ret = !strcmp("PNP0C0A", info->hardware_id.string);
234
235	kfree(info);
236	return ret;
237}
238
239static int is_ejectable_bay(acpi_handle handle)
240{
241	acpi_handle phandle;
242
243	if (!is_ejectable(handle))
244		return 0;
245	if (is_battery(handle) || is_ata(handle))
246		return 1;
247	if (!acpi_get_parent(handle, &phandle) && is_ata(phandle))
248		return 1;
249	return 0;
250}
251
252/**
253 * is_dock_device - see if a device is on a dock station
254 * @handle: acpi handle of the device
255 *
256 * If this device is either the dock station itself,
257 * or is a device dependent on the dock station, then it
258 * is a dock device
259 */
260int is_dock_device(acpi_handle handle)
261{
262	struct dock_station *dock_station;
263
264	if (!dock_station_count)
265		return 0;
266
267	if (is_dock(handle))
268		return 1;
269
270	list_for_each_entry(dock_station, &dock_stations, sibling)
271		if (find_dock_dependent_device(dock_station, handle))
272			return 1;
273
274	return 0;
275}
276EXPORT_SYMBOL_GPL(is_dock_device);
277
278/**
279 * dock_present - see if the dock station is present.
280 * @ds: the dock station
281 *
282 * execute the _STA method.  note that present does not
283 * imply that we are docked.
284 */
285static int dock_present(struct dock_station *ds)
286{
287	unsigned long long sta;
288	acpi_status status;
289
290	if (ds) {
291		status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
292		if (ACPI_SUCCESS(status) && sta)
293			return 1;
294	}
295	return 0;
296}
297
298/**
299 * dock_create_acpi_device - add new devices to acpi
300 * @handle - handle of the device to add
301 *
302 *  This function will create a new acpi_device for the given
303 *  handle if one does not exist already.  This should cause
304 *  acpi to scan for drivers for the given devices, and call
305 *  matching driver's add routine.
306 *
307 *  Returns a pointer to the acpi_device corresponding to the handle.
308 */
309static struct acpi_device * dock_create_acpi_device(acpi_handle handle)
310{
311	struct acpi_device *device;
312	struct acpi_device *parent_device;
313	acpi_handle parent;
314	int ret;
315
316	if (acpi_bus_get_device(handle, &device)) {
317		/*
318		 * no device created for this object,
319		 * so we should create one.
320		 */
321		acpi_get_parent(handle, &parent);
322		if (acpi_bus_get_device(parent, &parent_device))
323			parent_device = NULL;
324
325		ret = acpi_bus_add(&device, parent_device, handle,
326			ACPI_BUS_TYPE_DEVICE);
327		if (ret) {
328			pr_debug("error adding bus, %x\n", -ret);
329			return NULL;
330		}
331	}
332	return device;
333}
334
335/**
336 * dock_remove_acpi_device - remove the acpi_device struct from acpi
337 * @handle - the handle of the device to remove
338 *
339 *  Tell acpi to remove the acpi_device.  This should cause any loaded
340 *  driver to have it's remove routine called.
341 */
342static void dock_remove_acpi_device(acpi_handle handle)
343{
344	struct acpi_device *device;
345	int ret;
346
347	if (!acpi_bus_get_device(handle, &device)) {
348		ret = acpi_bus_trim(device, 1);
349		if (ret)
350			pr_debug("error removing bus, %x\n", -ret);
351	}
352}
353
354/**
355 * hotplug_dock_devices - insert or remove devices on the dock station
356 * @ds: the dock station
357 * @event: either bus check or eject request
358 *
359 * Some devices on the dock station need to have drivers called
360 * to perform hotplug operations after a dock event has occurred.
361 * Traverse the list of dock devices that have registered a
362 * hotplug handler, and call the handler.
363 */
364static void hotplug_dock_devices(struct dock_station *ds, u32 event)
365{
366	struct dock_dependent_device *dd;
367
368	mutex_lock(&ds->hp_lock);
369
370	/*
371	 * First call driver specific hotplug functions
372	 */
373	list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list)
374		if (dd->ops && dd->ops->handler)
375			dd->ops->handler(dd->handle, event, dd->context);
376
377	/*
378	 * Now make sure that an acpi_device is created for each
379	 * dependent device, or removed if this is an eject request.
380	 * This will cause acpi_drivers to be stopped/started if they
381	 * exist
382	 */
383	list_for_each_entry(dd, &ds->dependent_devices, list) {
384		if (event == ACPI_NOTIFY_EJECT_REQUEST)
385			dock_remove_acpi_device(dd->handle);
386		else
387			dock_create_acpi_device(dd->handle);
388	}
389	mutex_unlock(&ds->hp_lock);
390}
391
392static void dock_event(struct dock_station *ds, u32 event, int num)
393{
394	struct device *dev = &ds->dock_device->dev;
395	char event_string[13];
396	char *envp[] = { event_string, NULL };
397	struct dock_dependent_device *dd;
398
399	if (num == UNDOCK_EVENT)
400		sprintf(event_string, "EVENT=undock");
401	else
402		sprintf(event_string, "EVENT=dock");
403
404	/*
405	 * Indicate that the status of the dock station has
406	 * changed.
407	 */
408	if (num == DOCK_EVENT)
409		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
410
411	list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list)
412		if (dd->ops && dd->ops->uevent)
413			dd->ops->uevent(dd->handle, event, dd->context);
414
415	if (num != DOCK_EVENT)
416		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
417}
418
419/**
420 * eject_dock - respond to a dock eject request
421 * @ds: the dock station
422 *
423 * This is called after _DCK is called, to execute the dock station's
424 * _EJ0 method.
425 */
426static void eject_dock(struct dock_station *ds)
427{
428	struct acpi_object_list arg_list;
429	union acpi_object arg;
430	acpi_status status;
431	acpi_handle tmp;
432
433	/* all dock devices should have _EJ0, but check anyway */
434	status = acpi_get_handle(ds->handle, "_EJ0", &tmp);
435	if (ACPI_FAILURE(status)) {
436		pr_debug("No _EJ0 support for dock device\n");
437		return;
438	}
439
440	arg_list.count = 1;
441	arg_list.pointer = &arg;
442	arg.type = ACPI_TYPE_INTEGER;
443	arg.integer.value = 1;
444
445	status = acpi_evaluate_object(ds->handle, "_EJ0", &arg_list, NULL);
446	if (ACPI_FAILURE(status))
447		pr_debug("Failed to evaluate _EJ0!\n");
448}
449
450/**
451 * handle_dock - handle a dock event
452 * @ds: the dock station
453 * @dock: to dock, or undock - that is the question
454 *
455 * Execute the _DCK method in response to an acpi event
456 */
457static void handle_dock(struct dock_station *ds, int dock)
458{
459	acpi_status status;
460	struct acpi_object_list arg_list;
461	union acpi_object arg;
462	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
463	struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL };
464
465	acpi_get_name(ds->handle, ACPI_FULL_PATHNAME, &name_buffer);
466
467	printk(KERN_INFO PREFIX "%s - %s\n",
468		(char *)name_buffer.pointer, dock ? "docking" : "undocking");
469
470	/* _DCK method has one argument */
471	arg_list.count = 1;
472	arg_list.pointer = &arg;
473	arg.type = ACPI_TYPE_INTEGER;
474	arg.integer.value = dock;
475	status = acpi_evaluate_object(ds->handle, "_DCK", &arg_list, &buffer);
476	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
477		ACPI_EXCEPTION((AE_INFO, status, "%s - failed to execute"
478			" _DCK\n", (char *)name_buffer.pointer));
479
480	kfree(buffer.pointer);
481	kfree(name_buffer.pointer);
482}
483
484static inline void dock(struct dock_station *ds)
485{
486	handle_dock(ds, 1);
487}
488
489static inline void undock(struct dock_station *ds)
490{
491	handle_dock(ds, 0);
492}
493
494static inline void begin_dock(struct dock_station *ds)
495{
496	ds->flags |= DOCK_DOCKING;
497}
498
499static inline void complete_dock(struct dock_station *ds)
500{
501	ds->flags &= ~(DOCK_DOCKING);
502	ds->last_dock_time = jiffies;
503}
504
505static inline void begin_undock(struct dock_station *ds)
506{
507	ds->flags |= DOCK_UNDOCKING;
508}
509
510static inline void complete_undock(struct dock_station *ds)
511{
512	ds->flags &= ~(DOCK_UNDOCKING);
513}
514
515static void dock_lock(struct dock_station *ds, int lock)
516{
517	struct acpi_object_list arg_list;
518	union acpi_object arg;
519	acpi_status status;
520
521	arg_list.count = 1;
522	arg_list.pointer = &arg;
523	arg.type = ACPI_TYPE_INTEGER;
524	arg.integer.value = !!lock;
525	status = acpi_evaluate_object(ds->handle, "_LCK", &arg_list, NULL);
526	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
527		if (lock)
528			printk(KERN_WARNING PREFIX "Locking device failed\n");
529		else
530			printk(KERN_WARNING PREFIX "Unlocking device failed\n");
531	}
532}
533
534/**
535 * dock_in_progress - see if we are in the middle of handling a dock event
536 * @ds: the dock station
537 *
538 * Sometimes while docking, false dock events can be sent to the driver
539 * because good connections aren't made or some other reason.  Ignore these
540 * if we are in the middle of doing something.
541 */
542static int dock_in_progress(struct dock_station *ds)
543{
544	if ((ds->flags & DOCK_DOCKING) ||
545	    time_before(jiffies, (ds->last_dock_time + HZ)))
546		return 1;
547	return 0;
548}
549
550/**
551 * register_dock_notifier - add yourself to the dock notifier list
552 * @nb: the callers notifier block
553 *
554 * If a driver wishes to be notified about dock events, they can
555 * use this function to put a notifier block on the dock notifier list.
556 * this notifier call chain will be called after a dock event, but
557 * before hotplugging any new devices.
558 */
559int register_dock_notifier(struct notifier_block *nb)
560{
561	if (!dock_station_count)
562		return -ENODEV;
563
564	return atomic_notifier_chain_register(&dock_notifier_list, nb);
565}
566EXPORT_SYMBOL_GPL(register_dock_notifier);
567
568/**
569 * unregister_dock_notifier - remove yourself from the dock notifier list
570 * @nb: the callers notifier block
571 */
572void unregister_dock_notifier(struct notifier_block *nb)
573{
574	if (!dock_station_count)
575		return;
576
577	atomic_notifier_chain_unregister(&dock_notifier_list, nb);
578}
579EXPORT_SYMBOL_GPL(unregister_dock_notifier);
580
581/**
582 * register_hotplug_dock_device - register a hotplug function
583 * @handle: the handle of the device
584 * @ops: handlers to call after docking
585 * @context: device specific data
586 *
587 * If a driver would like to perform a hotplug operation after a dock
588 * event, they can register an acpi_notifiy_handler to be called by
589 * the dock driver after _DCK is executed.
590 */
591int
592register_hotplug_dock_device(acpi_handle handle, struct acpi_dock_ops *ops,
593			     void *context)
594{
595	struct dock_dependent_device *dd;
596	struct dock_station *dock_station;
597	int ret = -EINVAL;
598
599	if (!dock_station_count)
600		return -ENODEV;
601
602	/*
603	 * make sure this handle is for a device dependent on the dock,
604	 * this would include the dock station itself
605	 */
606	list_for_each_entry(dock_station, &dock_stations, sibling) {
607		/*
608		 * An ATA bay can be in a dock and itself can be ejected
609		 * separately, so there are two 'dock stations' which need the
610		 * ops
611		 */
612		dd = find_dock_dependent_device(dock_station, handle);
613		if (dd) {
614			dd->ops = ops;
615			dd->context = context;
616			dock_add_hotplug_device(dock_station, dd);
617			ret = 0;
618		}
619	}
620
621	return ret;
622}
623EXPORT_SYMBOL_GPL(register_hotplug_dock_device);
624
625/**
626 * unregister_hotplug_dock_device - remove yourself from the hotplug list
627 * @handle: the acpi handle of the device
628 */
629void unregister_hotplug_dock_device(acpi_handle handle)
630{
631	struct dock_dependent_device *dd;
632	struct dock_station *dock_station;
633
634	if (!dock_station_count)
635		return;
636
637	list_for_each_entry(dock_station, &dock_stations, sibling) {
638		dd = find_dock_dependent_device(dock_station, handle);
639		if (dd)
640			dock_del_hotplug_device(dock_station, dd);
641	}
642}
643EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device);
644
645/**
646 * handle_eject_request - handle an undock request checking for error conditions
647 *
648 * Check to make sure the dock device is still present, then undock and
649 * hotremove all the devices that may need removing.
650 */
651static int handle_eject_request(struct dock_station *ds, u32 event)
652{
653	if (dock_in_progress(ds))
654		return -EBUSY;
655
656	/*
657	 * here we need to generate the undock
658	 * event prior to actually doing the undock
659	 * so that the device struct still exists.
660	 * Also, even send the dock event if the
661	 * device is not present anymore
662	 */
663	dock_event(ds, event, UNDOCK_EVENT);
664
665	hotplug_dock_devices(ds, ACPI_NOTIFY_EJECT_REQUEST);
666	undock(ds);
667	dock_lock(ds, 0);
668	eject_dock(ds);
669	if (dock_present(ds)) {
670		printk(KERN_ERR PREFIX "Unable to undock!\n");
671		return -EBUSY;
672	}
673	complete_undock(ds);
674	return 0;
675}
676
677/**
678 * dock_notify - act upon an acpi dock notification
679 * @handle: the dock station handle
680 * @event: the acpi event
681 * @data: our driver data struct
682 *
683 * If we are notified to dock, then check to see if the dock is
684 * present and then dock.  Notify all drivers of the dock event,
685 * and then hotplug and devices that may need hotplugging.
686 */
687static void dock_notify(acpi_handle handle, u32 event, void *data)
688{
689	struct dock_station *ds = data;
690	struct acpi_device *tmp;
691	int surprise_removal = 0;
692
693	/*
694	 * According to acpi spec 3.0a, if a DEVICE_CHECK notification
695	 * is sent and _DCK is present, it is assumed to mean an undock
696	 * request.
697	 */
698	if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
699		event = ACPI_NOTIFY_EJECT_REQUEST;
700
701	/*
702	 * dock station: BUS_CHECK - docked or surprise removal
703	 *		 DEVICE_CHECK - undocked
704	 * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
705	 *
706	 * To simplify event handling, dock dependent device handler always
707	 * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
708	 * ACPI_NOTIFY_EJECT_REQUEST for removal
709	 */
710	switch (event) {
711	case ACPI_NOTIFY_BUS_CHECK:
712	case ACPI_NOTIFY_DEVICE_CHECK:
713		if (!dock_in_progress(ds) && acpi_bus_get_device(ds->handle,
714		   &tmp)) {
715			begin_dock(ds);
716			dock(ds);
717			if (!dock_present(ds)) {
718				printk(KERN_ERR PREFIX "Unable to dock!\n");
719				complete_dock(ds);
720				break;
721			}
722			atomic_notifier_call_chain(&dock_notifier_list,
723						   event, NULL);
724			hotplug_dock_devices(ds, event);
725			complete_dock(ds);
726			dock_event(ds, event, DOCK_EVENT);
727			dock_lock(ds, 1);
728			break;
729		}
730		if (dock_present(ds) || dock_in_progress(ds))
731			break;
732		/* This is a surprise removal */
733		surprise_removal = 1;
734		event = ACPI_NOTIFY_EJECT_REQUEST;
735		/* Fall back */
736	case ACPI_NOTIFY_EJECT_REQUEST:
737		begin_undock(ds);
738		if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
739		   || surprise_removal)
740			handle_eject_request(ds, event);
741		else
742			dock_event(ds, event, UNDOCK_EVENT);
743		break;
744	default:
745		printk(KERN_ERR PREFIX "Unknown dock event %d\n", event);
746	}
747}
748
749struct dock_data {
750	acpi_handle handle;
751	unsigned long event;
752	struct dock_station *ds;
753};
754
755static void acpi_dock_deferred_cb(void *context)
756{
757	struct dock_data *data = context;
758
759	dock_notify(data->handle, data->event, data->ds);
760	kfree(data);
761}
762
763static int acpi_dock_notifier_call(struct notifier_block *this,
764	unsigned long event, void *data)
765{
766	struct dock_station *dock_station;
767	acpi_handle handle = data;
768
769	if (event != ACPI_NOTIFY_BUS_CHECK && event != ACPI_NOTIFY_DEVICE_CHECK
770	   && event != ACPI_NOTIFY_EJECT_REQUEST)
771		return 0;
772	list_for_each_entry(dock_station, &dock_stations, sibling) {
773		if (dock_station->handle == handle) {
774			struct dock_data *dd;
775
776			dd = kmalloc(sizeof(*dd), GFP_KERNEL);
777			if (!dd)
778				return 0;
779			dd->handle = handle;
780			dd->event = event;
781			dd->ds = dock_station;
782			acpi_os_hotplug_execute(acpi_dock_deferred_cb, dd);
783			return 0 ;
784		}
785	}
786	return 0;
787}
788
789static struct notifier_block dock_acpi_notifier = {
790	.notifier_call = acpi_dock_notifier_call,
791};
792
793/**
794 * find_dock_devices - find devices on the dock station
795 * @handle: the handle of the device we are examining
796 * @lvl: unused
797 * @context: the dock station private data
798 * @rv: unused
799 *
800 * This function is called by acpi_walk_namespace.  It will
801 * check to see if an object has an _EJD method.  If it does, then it
802 * will see if it is dependent on the dock station.
803 */
804static acpi_status
805find_dock_devices(acpi_handle handle, u32 lvl, void *context, void **rv)
806{
807	acpi_status status;
808	acpi_handle tmp, parent;
809	struct dock_station *ds = context;
810
811	status = acpi_bus_get_ejd(handle, &tmp);
812	if (ACPI_FAILURE(status)) {
813		/* try the parent device as well */
814		status = acpi_get_parent(handle, &parent);
815		if (ACPI_FAILURE(status))
816			goto fdd_out;
817		/* see if parent is dependent on dock */
818		status = acpi_bus_get_ejd(parent, &tmp);
819		if (ACPI_FAILURE(status))
820			goto fdd_out;
821	}
822
823	if (tmp == ds->handle)
824		add_dock_dependent_device(ds, handle);
825
826fdd_out:
827	return AE_OK;
828}
829
830/*
831 * show_docked - read method for "docked" file in sysfs
832 */
833static ssize_t show_docked(struct device *dev,
834			   struct device_attribute *attr, char *buf)
835{
836	struct acpi_device *tmp;
837
838	struct dock_station *dock_station = dev->platform_data;
839
840	if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
841		return snprintf(buf, PAGE_SIZE, "1\n");
842	return snprintf(buf, PAGE_SIZE, "0\n");
843}
844static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
845
846/*
847 * show_flags - read method for flags file in sysfs
848 */
849static ssize_t show_flags(struct device *dev,
850			  struct device_attribute *attr, char *buf)
851{
852	struct dock_station *dock_station = dev->platform_data;
853	return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
854
855}
856static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
857
858/*
859 * write_undock - write method for "undock" file in sysfs
860 */
861static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
862			   const char *buf, size_t count)
863{
864	int ret;
865	struct dock_station *dock_station = dev->platform_data;
866
867	if (!count)
868		return -EINVAL;
869
870	begin_undock(dock_station);
871	ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
872	return ret ? ret: count;
873}
874static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
875
876/*
877 * show_dock_uid - read method for "uid" file in sysfs
878 */
879static ssize_t show_dock_uid(struct device *dev,
880			     struct device_attribute *attr, char *buf)
881{
882	unsigned long long lbuf;
883	struct dock_station *dock_station = dev->platform_data;
884	acpi_status status = acpi_evaluate_integer(dock_station->handle,
885					"_UID", NULL, &lbuf);
886	if (ACPI_FAILURE(status))
887	    return 0;
888
889	return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf);
890}
891static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
892
893static ssize_t show_dock_type(struct device *dev,
894		struct device_attribute *attr, char *buf)
895{
896	struct dock_station *dock_station = dev->platform_data;
897	char *type;
898
899	if (dock_station->flags & DOCK_IS_DOCK)
900		type = "dock_station";
901	else if (dock_station->flags & DOCK_IS_ATA)
902		type = "ata_bay";
903	else if (dock_station->flags & DOCK_IS_BAT)
904		type = "battery_bay";
905	else
906		type = "unknown";
907
908	return snprintf(buf, PAGE_SIZE, "%s\n", type);
909}
910static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
911
912static struct attribute *dock_attributes[] = {
913	&dev_attr_docked.attr,
914	&dev_attr_flags.attr,
915	&dev_attr_undock.attr,
916	&dev_attr_uid.attr,
917	&dev_attr_type.attr,
918	NULL
919};
920
921static struct attribute_group dock_attribute_group = {
922	.attrs = dock_attributes
923};
924
925/**
926 * dock_add - add a new dock station
927 * @handle: the dock station handle
928 *
929 * allocated and initialize a new dock station device.  Find all devices
930 * that are on the dock station, and register for dock event notifications.
931 */
932static int dock_add(acpi_handle handle)
933{
934	int ret, id;
935	struct dock_station ds, *dock_station;
936	struct platform_device *dd;
937
938	id = dock_station_count;
939	memset(&ds, 0, sizeof(ds));
940	dd = platform_device_register_data(NULL, "dock", id, &ds, sizeof(ds));
941	if (IS_ERR(dd))
942		return PTR_ERR(dd);
943
944	dock_station = dd->dev.platform_data;
945
946	dock_station->handle = handle;
947	dock_station->dock_device = dd;
948	dock_station->last_dock_time = jiffies - HZ;
949
950	mutex_init(&dock_station->hp_lock);
951	spin_lock_init(&dock_station->dd_lock);
952	INIT_LIST_HEAD(&dock_station->sibling);
953	INIT_LIST_HEAD(&dock_station->hotplug_devices);
954	ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);
955	INIT_LIST_HEAD(&dock_station->dependent_devices);
956
957	/* we want the dock device to send uevents */
958	dev_set_uevent_suppress(&dd->dev, 0);
959
960	if (is_dock(handle))
961		dock_station->flags |= DOCK_IS_DOCK;
962	if (is_ata(handle))
963		dock_station->flags |= DOCK_IS_ATA;
964	if (is_battery(handle))
965		dock_station->flags |= DOCK_IS_BAT;
966
967	ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
968	if (ret)
969		goto err_unregister;
970
971	/* Find dependent devices */
972	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
973			    ACPI_UINT32_MAX, find_dock_devices, NULL,
974			    dock_station, NULL);
975
976	/* add the dock station as a device dependent on itself */
977	ret = add_dock_dependent_device(dock_station, handle);
978	if (ret)
979		goto err_rmgroup;
980
981	dock_station_count++;
982	list_add(&dock_station->sibling, &dock_stations);
983	return 0;
984
985err_rmgroup:
986	sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
987err_unregister:
988	platform_device_unregister(dd);
989	printk(KERN_ERR "%s encountered error %d\n", __func__, ret);
990	return ret;
991}
992
993/**
994 * dock_remove - free up resources related to the dock station
995 */
996static int dock_remove(struct dock_station *ds)
997{
998	struct dock_dependent_device *dd, *tmp;
999	struct platform_device *dock_device = ds->dock_device;
1000
1001	if (!dock_station_count)
1002		return 0;
1003
1004	/* remove dependent devices */
1005	list_for_each_entry_safe(dd, tmp, &ds->dependent_devices, list)
1006		kfree(dd);
1007
1008	list_del(&ds->sibling);
1009
1010	/* cleanup sysfs */
1011	sysfs_remove_group(&dock_device->dev.kobj, &dock_attribute_group);
1012	platform_device_unregister(dock_device);
1013
1014	return 0;
1015}
1016
1017/**
1018 * find_dock - look for a dock station
1019 * @handle: acpi handle of a device
1020 * @lvl: unused
1021 * @context: counter of dock stations found
1022 * @rv: unused
1023 *
1024 * This is called by acpi_walk_namespace to look for dock stations.
1025 */
1026static acpi_status
1027find_dock(acpi_handle handle, u32 lvl, void *context, void **rv)
1028{
1029	if (is_dock(handle))
1030		dock_add(handle);
1031
1032	return AE_OK;
1033}
1034
1035static acpi_status
1036find_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
1037{
1038	/* If bay is a dock, it's already handled */
1039	if (is_ejectable_bay(handle) && !is_dock(handle))
1040		dock_add(handle);
1041	return AE_OK;
1042}
1043
1044static int __init dock_init(void)
1045{
1046	if (acpi_disabled)
1047		return 0;
1048
1049	/* look for a dock station */
1050	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
1051			    ACPI_UINT32_MAX, find_dock, NULL, NULL, NULL);
1052
1053	/* look for bay */
1054	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
1055			ACPI_UINT32_MAX, find_bay, NULL, NULL, NULL);
1056	if (!dock_station_count) {
1057		printk(KERN_INFO PREFIX "No dock devices found.\n");
1058		return 0;
1059	}
1060
1061	register_acpi_bus_notifier(&dock_acpi_notifier);
1062	printk(KERN_INFO PREFIX "%s: %d docks/bays found\n",
1063		ACPI_DOCK_DRIVER_DESCRIPTION, dock_station_count);
1064	return 0;
1065}
1066
1067static void __exit dock_exit(void)
1068{
1069	struct dock_station *tmp, *dock_station;
1070
1071	unregister_acpi_bus_notifier(&dock_acpi_notifier);
1072	list_for_each_entry_safe(dock_station, tmp, &dock_stations, sibling)
1073		dock_remove(dock_station);
1074}
1075
1076/*
1077 * Must be called before drivers of devices in dock, otherwise we can't know
1078 * which devices are in a dock
1079 */
1080subsys_initcall(dock_init);
1081module_exit(dock_exit);
1082