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v5.9
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  dock.c - ACPI dock station driver
  4 *
  5 *  Copyright (C) 2006, 2014, Intel Corp.
  6 *  Author: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
  7 *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  8 */
  9
 10#include <linux/kernel.h>
 11#include <linux/moduleparam.h>
 12#include <linux/slab.h>
 13#include <linux/init.h>
 14#include <linux/types.h>
 15#include <linux/notifier.h>
 16#include <linux/platform_device.h>
 17#include <linux/jiffies.h>
 18#include <linux/stddef.h>
 19#include <linux/acpi.h>
 20
 21#include "internal.h"
 22
 23ACPI_MODULE_NAME("dock");
 24
 25static bool immediate_undock = 1;
 26module_param(immediate_undock, bool, 0644);
 27MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
 28	"undock immediately when the undock button is pressed, 0 will cause"
 29	" the driver to wait for userspace to write the undock sysfs file "
 30	" before undocking");
 31
 32struct dock_station {
 33	acpi_handle handle;
 34	unsigned long last_dock_time;
 35	u32 flags;
 36	struct list_head dependent_devices;
 37
 38	struct list_head sibling;
 39	struct platform_device *dock_device;
 40};
 41static LIST_HEAD(dock_stations);
 42static int dock_station_count;
 43
 44struct dock_dependent_device {
 45	struct list_head list;
 46	struct acpi_device *adev;
 47};
 48
 49#define DOCK_DOCKING	0x00000001
 50#define DOCK_UNDOCKING  0x00000002
 51#define DOCK_IS_DOCK	0x00000010
 52#define DOCK_IS_ATA	0x00000020
 53#define DOCK_IS_BAT	0x00000040
 54#define DOCK_EVENT	3
 55#define UNDOCK_EVENT	2
 56
 57enum dock_callback_type {
 58	DOCK_CALL_HANDLER,
 59	DOCK_CALL_FIXUP,
 60	DOCK_CALL_UEVENT,
 61};
 62
 63/*****************************************************************************
 64 *                         Dock Dependent device functions                   *
 65 *****************************************************************************/
 66/**
 67 * add_dock_dependent_device - associate a device with the dock station
 68 * @ds: Dock station.
 69 * @adev: Dependent ACPI device object.
 70 *
 71 * Add the dependent device to the dock's dependent device list.
 72 */
 73static int add_dock_dependent_device(struct dock_station *ds,
 74				     struct acpi_device *adev)
 75{
 76	struct dock_dependent_device *dd;
 77
 78	dd = kzalloc(sizeof(*dd), GFP_KERNEL);
 79	if (!dd)
 80		return -ENOMEM;
 81
 82	dd->adev = adev;
 83	INIT_LIST_HEAD(&dd->list);
 84	list_add_tail(&dd->list, &ds->dependent_devices);
 85
 86	return 0;
 87}
 88
 89static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
 90			       enum dock_callback_type cb_type)
 91{
 92	struct acpi_device *adev = dd->adev;
 93
 94	acpi_lock_hp_context();
 95
 96	if (!adev->hp)
 97		goto out;
 98
 99	if (cb_type == DOCK_CALL_FIXUP) {
100		void (*fixup)(struct acpi_device *);
101
102		fixup = adev->hp->fixup;
103		if (fixup) {
104			acpi_unlock_hp_context();
105			fixup(adev);
106			return;
107		}
108	} else if (cb_type == DOCK_CALL_UEVENT) {
109		void (*uevent)(struct acpi_device *, u32);
110
111		uevent = adev->hp->uevent;
112		if (uevent) {
113			acpi_unlock_hp_context();
114			uevent(adev, event);
115			return;
116		}
117	} else {
118		int (*notify)(struct acpi_device *, u32);
119
120		notify = adev->hp->notify;
121		if (notify) {
122			acpi_unlock_hp_context();
123			notify(adev, event);
124			return;
125		}
126	}
127
128 out:
129	acpi_unlock_hp_context();
130}
131
132static struct dock_station *find_dock_station(acpi_handle handle)
133{
134	struct dock_station *ds;
135
136	list_for_each_entry(ds, &dock_stations, sibling)
137		if (ds->handle == handle)
138			return ds;
139
140	return NULL;
141}
142
143/**
144 * find_dock_dependent_device - get a device dependent on this dock
145 * @ds: the dock station
146 * @adev: ACPI device object to find.
147 *
148 * iterate over the dependent device list for this dock.  If the
149 * dependent device matches the handle, return.
150 */
151static struct dock_dependent_device *
152find_dock_dependent_device(struct dock_station *ds, struct acpi_device *adev)
153{
154	struct dock_dependent_device *dd;
155
156	list_for_each_entry(dd, &ds->dependent_devices, list)
157		if (adev == dd->adev)
158			return dd;
159
160	return NULL;
161}
162
163void register_dock_dependent_device(struct acpi_device *adev,
164				    acpi_handle dshandle)
165{
166	struct dock_station *ds = find_dock_station(dshandle);
167
168	if (ds && !find_dock_dependent_device(ds, adev))
169		add_dock_dependent_device(ds, adev);
170}
171
172/*****************************************************************************
173 *                         Dock functions                                    *
174 *****************************************************************************/
175
176/**
177 * is_dock_device - see if a device is on a dock station
178 * @adev: ACPI device object to check.
179 *
180 * If this device is either the dock station itself,
181 * or is a device dependent on the dock station, then it
182 * is a dock device
183 */
184int is_dock_device(struct acpi_device *adev)
185{
186	struct dock_station *dock_station;
187
188	if (!dock_station_count)
189		return 0;
190
191	if (acpi_dock_match(adev->handle))
192		return 1;
193
194	list_for_each_entry(dock_station, &dock_stations, sibling)
195		if (find_dock_dependent_device(dock_station, adev))
196			return 1;
197
198	return 0;
199}
200EXPORT_SYMBOL_GPL(is_dock_device);
201
202/**
203 * dock_present - see if the dock station is present.
204 * @ds: the dock station
205 *
206 * execute the _STA method.  note that present does not
207 * imply that we are docked.
208 */
209static int dock_present(struct dock_station *ds)
210{
211	unsigned long long sta;
212	acpi_status status;
213
214	if (ds) {
215		status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
216		if (ACPI_SUCCESS(status) && sta)
217			return 1;
218	}
219	return 0;
220}
221
222/**
223 * hot_remove_dock_devices - Remove dock station devices.
224 * @ds: Dock station.
225 */
226static void hot_remove_dock_devices(struct dock_station *ds)
227{
228	struct dock_dependent_device *dd;
229
230	/*
231	 * Walk the list in reverse order so that devices that have been added
232	 * last are removed first (in case there are some indirect dependencies
233	 * between them).
234	 */
235	list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
236		dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST, false);
237
238	list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
239		acpi_bus_trim(dd->adev);
240}
241
242/**
243 * hotplug_dock_devices - Insert devices on a dock station.
244 * @ds: the dock station
245 * @event: either bus check or device check request
246 *
247 * Some devices on the dock station need to have drivers called
248 * to perform hotplug operations after a dock event has occurred.
249 * Traverse the list of dock devices that have registered a
250 * hotplug handler, and call the handler.
251 */
252static void hotplug_dock_devices(struct dock_station *ds, u32 event)
253{
254	struct dock_dependent_device *dd;
255
256	/* Call driver specific post-dock fixups. */
257	list_for_each_entry(dd, &ds->dependent_devices, list)
258		dock_hotplug_event(dd, event, DOCK_CALL_FIXUP);
259
260	/* Call driver specific hotplug functions. */
261	list_for_each_entry(dd, &ds->dependent_devices, list)
262		dock_hotplug_event(dd, event, DOCK_CALL_HANDLER);
263
264	/*
265	 * Check if all devices have been enumerated already.  If not, run
266	 * acpi_bus_scan() for them and that will cause scan handlers to be
267	 * attached to device objects or acpi_drivers to be stopped/started if
268	 * they are present.
269	 */
270	list_for_each_entry(dd, &ds->dependent_devices, list) {
271		struct acpi_device *adev = dd->adev;
272
273		if (!acpi_device_enumerated(adev)) {
274			int ret = acpi_bus_scan(adev->handle);
275			if (ret)
276				dev_dbg(&adev->dev, "scan error %d\n", -ret);
277		}
278	}
279}
280
281static void dock_event(struct dock_station *ds, u32 event, int num)
282{
283	struct device *dev = &ds->dock_device->dev;
284	char event_string[13];
285	char *envp[] = { event_string, NULL };
286	struct dock_dependent_device *dd;
287
288	if (num == UNDOCK_EVENT)
289		sprintf(event_string, "EVENT=undock");
290	else
291		sprintf(event_string, "EVENT=dock");
292
293	/*
294	 * Indicate that the status of the dock station has
295	 * changed.
296	 */
297	if (num == DOCK_EVENT)
298		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
299
300	list_for_each_entry(dd, &ds->dependent_devices, list)
301		dock_hotplug_event(dd, event, DOCK_CALL_UEVENT);
302
303	if (num != DOCK_EVENT)
304		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
305}
306
307/**
308 * handle_dock - handle a dock event
309 * @ds: the dock station
310 * @dock: to dock, or undock - that is the question
311 *
312 * Execute the _DCK method in response to an acpi event
313 */
314static void handle_dock(struct dock_station *ds, int dock)
315{
316	acpi_status status;
317	struct acpi_object_list arg_list;
318	union acpi_object arg;
319	unsigned long long value;
320
321	acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking");
322
323	/* _DCK method has one argument */
324	arg_list.count = 1;
325	arg_list.pointer = &arg;
326	arg.type = ACPI_TYPE_INTEGER;
327	arg.integer.value = dock;
328	status = acpi_evaluate_integer(ds->handle, "_DCK", &arg_list, &value);
329	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
330		acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n",
331				status);
332}
333
334static inline void dock(struct dock_station *ds)
335{
336	handle_dock(ds, 1);
337}
338
339static inline void undock(struct dock_station *ds)
340{
341	handle_dock(ds, 0);
342}
343
344static inline void begin_dock(struct dock_station *ds)
345{
346	ds->flags |= DOCK_DOCKING;
347}
348
349static inline void complete_dock(struct dock_station *ds)
350{
351	ds->flags &= ~(DOCK_DOCKING);
352	ds->last_dock_time = jiffies;
353}
354
355static inline void begin_undock(struct dock_station *ds)
356{
357	ds->flags |= DOCK_UNDOCKING;
358}
359
360static inline void complete_undock(struct dock_station *ds)
361{
362	ds->flags &= ~(DOCK_UNDOCKING);
363}
364
365/**
366 * dock_in_progress - see if we are in the middle of handling a dock event
367 * @ds: the dock station
368 *
369 * Sometimes while docking, false dock events can be sent to the driver
370 * because good connections aren't made or some other reason.  Ignore these
371 * if we are in the middle of doing something.
372 */
373static int dock_in_progress(struct dock_station *ds)
374{
375	if ((ds->flags & DOCK_DOCKING) ||
376	    time_before(jiffies, (ds->last_dock_time + HZ)))
377		return 1;
378	return 0;
379}
380
381/**
382 * handle_eject_request - handle an undock request checking for error conditions
383 *
384 * Check to make sure the dock device is still present, then undock and
385 * hotremove all the devices that may need removing.
386 */
387static int handle_eject_request(struct dock_station *ds, u32 event)
388{
389	if (dock_in_progress(ds))
390		return -EBUSY;
391
392	/*
393	 * here we need to generate the undock
394	 * event prior to actually doing the undock
395	 * so that the device struct still exists.
396	 * Also, even send the dock event if the
397	 * device is not present anymore
398	 */
399	dock_event(ds, event, UNDOCK_EVENT);
400
401	hot_remove_dock_devices(ds);
402	undock(ds);
403	acpi_evaluate_lck(ds->handle, 0);
404	acpi_evaluate_ej0(ds->handle);
405	if (dock_present(ds)) {
406		acpi_handle_err(ds->handle, "Unable to undock!\n");
407		return -EBUSY;
408	}
409	complete_undock(ds);
410	return 0;
411}
412
413/**
414 * dock_notify - Handle ACPI dock notification.
415 * @adev: Dock station's ACPI device object.
416 * @event: Event code.
417 *
418 * If we are notified to dock, then check to see if the dock is
419 * present and then dock.  Notify all drivers of the dock event,
420 * and then hotplug and devices that may need hotplugging.
421 */
422int dock_notify(struct acpi_device *adev, u32 event)
423{
424	acpi_handle handle = adev->handle;
425	struct dock_station *ds = find_dock_station(handle);
426	int surprise_removal = 0;
427
428	if (!ds)
429		return -ENODEV;
430
431	/*
432	 * According to acpi spec 3.0a, if a DEVICE_CHECK notification
433	 * is sent and _DCK is present, it is assumed to mean an undock
434	 * request.
435	 */
436	if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
437		event = ACPI_NOTIFY_EJECT_REQUEST;
438
439	/*
440	 * dock station: BUS_CHECK - docked or surprise removal
441	 *		 DEVICE_CHECK - undocked
442	 * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
443	 *
444	 * To simplify event handling, dock dependent device handler always
445	 * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
446	 * ACPI_NOTIFY_EJECT_REQUEST for removal
447	 */
448	switch (event) {
449	case ACPI_NOTIFY_BUS_CHECK:
450	case ACPI_NOTIFY_DEVICE_CHECK:
451		if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) {
452			begin_dock(ds);
453			dock(ds);
454			if (!dock_present(ds)) {
455				acpi_handle_err(handle, "Unable to dock!\n");
456				complete_dock(ds);
457				break;
458			}
459			hotplug_dock_devices(ds, event);
460			complete_dock(ds);
461			dock_event(ds, event, DOCK_EVENT);
462			acpi_evaluate_lck(ds->handle, 1);
463			acpi_update_all_gpes();
464			break;
465		}
466		if (dock_present(ds) || dock_in_progress(ds))
467			break;
468		/* This is a surprise removal */
469		surprise_removal = 1;
470		event = ACPI_NOTIFY_EJECT_REQUEST;
471		/* Fall back */
472		fallthrough;
473	case ACPI_NOTIFY_EJECT_REQUEST:
474		begin_undock(ds);
475		if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
476		   || surprise_removal)
477			handle_eject_request(ds, event);
478		else
479			dock_event(ds, event, UNDOCK_EVENT);
480		break;
481	}
482	return 0;
483}
484
485/*
486 * show_docked - read method for "docked" file in sysfs
487 */
488static ssize_t show_docked(struct device *dev,
489			   struct device_attribute *attr, char *buf)
490{
491	struct dock_station *dock_station = dev->platform_data;
492	struct acpi_device *adev = NULL;
493
494	acpi_bus_get_device(dock_station->handle, &adev);
495	return snprintf(buf, PAGE_SIZE, "%u\n", acpi_device_enumerated(adev));
496}
497static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
498
499/*
500 * show_flags - read method for flags file in sysfs
501 */
502static ssize_t show_flags(struct device *dev,
503			  struct device_attribute *attr, char *buf)
504{
505	struct dock_station *dock_station = dev->platform_data;
506	return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
507
508}
509static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
510
511/*
512 * write_undock - write method for "undock" file in sysfs
513 */
514static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
515			   const char *buf, size_t count)
516{
517	int ret;
518	struct dock_station *dock_station = dev->platform_data;
519
520	if (!count)
521		return -EINVAL;
522
523	acpi_scan_lock_acquire();
524	begin_undock(dock_station);
525	ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
526	acpi_scan_lock_release();
527	return ret ? ret: count;
528}
529static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
530
531/*
532 * show_dock_uid - read method for "uid" file in sysfs
533 */
534static ssize_t show_dock_uid(struct device *dev,
535			     struct device_attribute *attr, char *buf)
536{
537	unsigned long long lbuf;
538	struct dock_station *dock_station = dev->platform_data;
539	acpi_status status = acpi_evaluate_integer(dock_station->handle,
540					"_UID", NULL, &lbuf);
541	if (ACPI_FAILURE(status))
542	    return 0;
543
544	return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf);
545}
546static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
547
548static ssize_t show_dock_type(struct device *dev,
549		struct device_attribute *attr, char *buf)
550{
551	struct dock_station *dock_station = dev->platform_data;
552	char *type;
553
554	if (dock_station->flags & DOCK_IS_DOCK)
555		type = "dock_station";
556	else if (dock_station->flags & DOCK_IS_ATA)
557		type = "ata_bay";
558	else if (dock_station->flags & DOCK_IS_BAT)
559		type = "battery_bay";
560	else
561		type = "unknown";
562
563	return snprintf(buf, PAGE_SIZE, "%s\n", type);
564}
565static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
566
567static struct attribute *dock_attributes[] = {
568	&dev_attr_docked.attr,
569	&dev_attr_flags.attr,
570	&dev_attr_undock.attr,
571	&dev_attr_uid.attr,
572	&dev_attr_type.attr,
573	NULL
574};
575
576static const struct attribute_group dock_attribute_group = {
577	.attrs = dock_attributes
578};
579
580/**
581 * acpi_dock_add - Add a new dock station
582 * @adev: Dock station ACPI device object.
583 *
584 * allocated and initialize a new dock station device.
585 */
586void acpi_dock_add(struct acpi_device *adev)
587{
588	struct dock_station *dock_station, ds = { NULL, };
589	struct platform_device_info pdevinfo;
590	acpi_handle handle = adev->handle;
591	struct platform_device *dd;
592	int ret;
593
594	memset(&pdevinfo, 0, sizeof(pdevinfo));
595	pdevinfo.name = "dock";
596	pdevinfo.id = dock_station_count;
597	pdevinfo.fwnode = acpi_fwnode_handle(adev);
598	pdevinfo.data = &ds;
599	pdevinfo.size_data = sizeof(ds);
600	dd = platform_device_register_full(&pdevinfo);
601	if (IS_ERR(dd))
602		return;
603
604	dock_station = dd->dev.platform_data;
605
606	dock_station->handle = handle;
607	dock_station->dock_device = dd;
608	dock_station->last_dock_time = jiffies - HZ;
609
610	INIT_LIST_HEAD(&dock_station->sibling);
611	INIT_LIST_HEAD(&dock_station->dependent_devices);
612
613	/* we want the dock device to send uevents */
614	dev_set_uevent_suppress(&dd->dev, 0);
615
616	if (acpi_dock_match(handle))
617		dock_station->flags |= DOCK_IS_DOCK;
618	if (acpi_ata_match(handle))
619		dock_station->flags |= DOCK_IS_ATA;
620	if (acpi_device_is_battery(adev))
621		dock_station->flags |= DOCK_IS_BAT;
622
623	ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
624	if (ret)
625		goto err_unregister;
626
627	/* add the dock station as a device dependent on itself */
628	ret = add_dock_dependent_device(dock_station, adev);
629	if (ret)
630		goto err_rmgroup;
631
632	dock_station_count++;
633	list_add(&dock_station->sibling, &dock_stations);
634	adev->flags.is_dock_station = true;
635	dev_info(&adev->dev, "ACPI dock station (docks/bays count: %d)\n",
636		 dock_station_count);
637	return;
638
639err_rmgroup:
640	sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
641
642err_unregister:
643	platform_device_unregister(dd);
644	acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
645}
v4.17
 
  1/*
  2 *  dock.c - ACPI dock station driver
  3 *
  4 *  Copyright (C) 2006, 2014, Intel Corp.
  5 *  Author: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
  6 *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  7 *
  8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  9 *
 10 *  This program is free software; you can redistribute it and/or modify
 11 *  it under the terms of the GNU General Public License as published by
 12 *  the Free Software Foundation; either version 2 of the License, or (at
 13 *  your option) any later version.
 14 *
 15 *  This program is distributed in the hope that it will be useful, but
 16 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 18 *  General Public License for more details.
 19 *
 20 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 21 */
 22
 23#include <linux/kernel.h>
 24#include <linux/moduleparam.h>
 25#include <linux/slab.h>
 26#include <linux/init.h>
 27#include <linux/types.h>
 28#include <linux/notifier.h>
 29#include <linux/platform_device.h>
 30#include <linux/jiffies.h>
 31#include <linux/stddef.h>
 32#include <linux/acpi.h>
 33
 34#include "internal.h"
 35
 36ACPI_MODULE_NAME("dock");
 37
 38static bool immediate_undock = 1;
 39module_param(immediate_undock, bool, 0644);
 40MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
 41	"undock immediately when the undock button is pressed, 0 will cause"
 42	" the driver to wait for userspace to write the undock sysfs file "
 43	" before undocking");
 44
 45struct dock_station {
 46	acpi_handle handle;
 47	unsigned long last_dock_time;
 48	u32 flags;
 49	struct list_head dependent_devices;
 50
 51	struct list_head sibling;
 52	struct platform_device *dock_device;
 53};
 54static LIST_HEAD(dock_stations);
 55static int dock_station_count;
 56
 57struct dock_dependent_device {
 58	struct list_head list;
 59	struct acpi_device *adev;
 60};
 61
 62#define DOCK_DOCKING	0x00000001
 63#define DOCK_UNDOCKING  0x00000002
 64#define DOCK_IS_DOCK	0x00000010
 65#define DOCK_IS_ATA	0x00000020
 66#define DOCK_IS_BAT	0x00000040
 67#define DOCK_EVENT	3
 68#define UNDOCK_EVENT	2
 69
 70enum dock_callback_type {
 71	DOCK_CALL_HANDLER,
 72	DOCK_CALL_FIXUP,
 73	DOCK_CALL_UEVENT,
 74};
 75
 76/*****************************************************************************
 77 *                         Dock Dependent device functions                   *
 78 *****************************************************************************/
 79/**
 80 * add_dock_dependent_device - associate a device with the dock station
 81 * @ds: Dock station.
 82 * @adev: Dependent ACPI device object.
 83 *
 84 * Add the dependent device to the dock's dependent device list.
 85 */
 86static int add_dock_dependent_device(struct dock_station *ds,
 87				     struct acpi_device *adev)
 88{
 89	struct dock_dependent_device *dd;
 90
 91	dd = kzalloc(sizeof(*dd), GFP_KERNEL);
 92	if (!dd)
 93		return -ENOMEM;
 94
 95	dd->adev = adev;
 96	INIT_LIST_HEAD(&dd->list);
 97	list_add_tail(&dd->list, &ds->dependent_devices);
 98
 99	return 0;
100}
101
102static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
103			       enum dock_callback_type cb_type)
104{
105	struct acpi_device *adev = dd->adev;
106
107	acpi_lock_hp_context();
108
109	if (!adev->hp)
110		goto out;
111
112	if (cb_type == DOCK_CALL_FIXUP) {
113		void (*fixup)(struct acpi_device *);
114
115		fixup = adev->hp->fixup;
116		if (fixup) {
117			acpi_unlock_hp_context();
118			fixup(adev);
119			return;
120		}
121	} else if (cb_type == DOCK_CALL_UEVENT) {
122		void (*uevent)(struct acpi_device *, u32);
123
124		uevent = adev->hp->uevent;
125		if (uevent) {
126			acpi_unlock_hp_context();
127			uevent(adev, event);
128			return;
129		}
130	} else {
131		int (*notify)(struct acpi_device *, u32);
132
133		notify = adev->hp->notify;
134		if (notify) {
135			acpi_unlock_hp_context();
136			notify(adev, event);
137			return;
138		}
139	}
140
141 out:
142	acpi_unlock_hp_context();
143}
144
145static struct dock_station *find_dock_station(acpi_handle handle)
146{
147	struct dock_station *ds;
148
149	list_for_each_entry(ds, &dock_stations, sibling)
150		if (ds->handle == handle)
151			return ds;
152
153	return NULL;
154}
155
156/**
157 * find_dock_dependent_device - get a device dependent on this dock
158 * @ds: the dock station
159 * @adev: ACPI device object to find.
160 *
161 * iterate over the dependent device list for this dock.  If the
162 * dependent device matches the handle, return.
163 */
164static struct dock_dependent_device *
165find_dock_dependent_device(struct dock_station *ds, struct acpi_device *adev)
166{
167	struct dock_dependent_device *dd;
168
169	list_for_each_entry(dd, &ds->dependent_devices, list)
170		if (adev == dd->adev)
171			return dd;
172
173	return NULL;
174}
175
176void register_dock_dependent_device(struct acpi_device *adev,
177				    acpi_handle dshandle)
178{
179	struct dock_station *ds = find_dock_station(dshandle);
180
181	if (ds && !find_dock_dependent_device(ds, adev))
182		add_dock_dependent_device(ds, adev);
183}
184
185/*****************************************************************************
186 *                         Dock functions                                    *
187 *****************************************************************************/
188
189/**
190 * is_dock_device - see if a device is on a dock station
191 * @adev: ACPI device object to check.
192 *
193 * If this device is either the dock station itself,
194 * or is a device dependent on the dock station, then it
195 * is a dock device
196 */
197int is_dock_device(struct acpi_device *adev)
198{
199	struct dock_station *dock_station;
200
201	if (!dock_station_count)
202		return 0;
203
204	if (acpi_dock_match(adev->handle))
205		return 1;
206
207	list_for_each_entry(dock_station, &dock_stations, sibling)
208		if (find_dock_dependent_device(dock_station, adev))
209			return 1;
210
211	return 0;
212}
213EXPORT_SYMBOL_GPL(is_dock_device);
214
215/**
216 * dock_present - see if the dock station is present.
217 * @ds: the dock station
218 *
219 * execute the _STA method.  note that present does not
220 * imply that we are docked.
221 */
222static int dock_present(struct dock_station *ds)
223{
224	unsigned long long sta;
225	acpi_status status;
226
227	if (ds) {
228		status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
229		if (ACPI_SUCCESS(status) && sta)
230			return 1;
231	}
232	return 0;
233}
234
235/**
236 * hot_remove_dock_devices - Remove dock station devices.
237 * @ds: Dock station.
238 */
239static void hot_remove_dock_devices(struct dock_station *ds)
240{
241	struct dock_dependent_device *dd;
242
243	/*
244	 * Walk the list in reverse order so that devices that have been added
245	 * last are removed first (in case there are some indirect dependencies
246	 * between them).
247	 */
248	list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
249		dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST, false);
250
251	list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
252		acpi_bus_trim(dd->adev);
253}
254
255/**
256 * hotplug_dock_devices - Insert devices on a dock station.
257 * @ds: the dock station
258 * @event: either bus check or device check request
259 *
260 * Some devices on the dock station need to have drivers called
261 * to perform hotplug operations after a dock event has occurred.
262 * Traverse the list of dock devices that have registered a
263 * hotplug handler, and call the handler.
264 */
265static void hotplug_dock_devices(struct dock_station *ds, u32 event)
266{
267	struct dock_dependent_device *dd;
268
269	/* Call driver specific post-dock fixups. */
270	list_for_each_entry(dd, &ds->dependent_devices, list)
271		dock_hotplug_event(dd, event, DOCK_CALL_FIXUP);
272
273	/* Call driver specific hotplug functions. */
274	list_for_each_entry(dd, &ds->dependent_devices, list)
275		dock_hotplug_event(dd, event, DOCK_CALL_HANDLER);
276
277	/*
278	 * Check if all devices have been enumerated already.  If not, run
279	 * acpi_bus_scan() for them and that will cause scan handlers to be
280	 * attached to device objects or acpi_drivers to be stopped/started if
281	 * they are present.
282	 */
283	list_for_each_entry(dd, &ds->dependent_devices, list) {
284		struct acpi_device *adev = dd->adev;
285
286		if (!acpi_device_enumerated(adev)) {
287			int ret = acpi_bus_scan(adev->handle);
288			if (ret)
289				dev_dbg(&adev->dev, "scan error %d\n", -ret);
290		}
291	}
292}
293
294static void dock_event(struct dock_station *ds, u32 event, int num)
295{
296	struct device *dev = &ds->dock_device->dev;
297	char event_string[13];
298	char *envp[] = { event_string, NULL };
299	struct dock_dependent_device *dd;
300
301	if (num == UNDOCK_EVENT)
302		sprintf(event_string, "EVENT=undock");
303	else
304		sprintf(event_string, "EVENT=dock");
305
306	/*
307	 * Indicate that the status of the dock station has
308	 * changed.
309	 */
310	if (num == DOCK_EVENT)
311		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
312
313	list_for_each_entry(dd, &ds->dependent_devices, list)
314		dock_hotplug_event(dd, event, DOCK_CALL_UEVENT);
315
316	if (num != DOCK_EVENT)
317		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
318}
319
320/**
321 * handle_dock - handle a dock event
322 * @ds: the dock station
323 * @dock: to dock, or undock - that is the question
324 *
325 * Execute the _DCK method in response to an acpi event
326 */
327static void handle_dock(struct dock_station *ds, int dock)
328{
329	acpi_status status;
330	struct acpi_object_list arg_list;
331	union acpi_object arg;
332	unsigned long long value;
333
334	acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking");
335
336	/* _DCK method has one argument */
337	arg_list.count = 1;
338	arg_list.pointer = &arg;
339	arg.type = ACPI_TYPE_INTEGER;
340	arg.integer.value = dock;
341	status = acpi_evaluate_integer(ds->handle, "_DCK", &arg_list, &value);
342	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
343		acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n",
344				status);
345}
346
347static inline void dock(struct dock_station *ds)
348{
349	handle_dock(ds, 1);
350}
351
352static inline void undock(struct dock_station *ds)
353{
354	handle_dock(ds, 0);
355}
356
357static inline void begin_dock(struct dock_station *ds)
358{
359	ds->flags |= DOCK_DOCKING;
360}
361
362static inline void complete_dock(struct dock_station *ds)
363{
364	ds->flags &= ~(DOCK_DOCKING);
365	ds->last_dock_time = jiffies;
366}
367
368static inline void begin_undock(struct dock_station *ds)
369{
370	ds->flags |= DOCK_UNDOCKING;
371}
372
373static inline void complete_undock(struct dock_station *ds)
374{
375	ds->flags &= ~(DOCK_UNDOCKING);
376}
377
378/**
379 * dock_in_progress - see if we are in the middle of handling a dock event
380 * @ds: the dock station
381 *
382 * Sometimes while docking, false dock events can be sent to the driver
383 * because good connections aren't made or some other reason.  Ignore these
384 * if we are in the middle of doing something.
385 */
386static int dock_in_progress(struct dock_station *ds)
387{
388	if ((ds->flags & DOCK_DOCKING) ||
389	    time_before(jiffies, (ds->last_dock_time + HZ)))
390		return 1;
391	return 0;
392}
393
394/**
395 * handle_eject_request - handle an undock request checking for error conditions
396 *
397 * Check to make sure the dock device is still present, then undock and
398 * hotremove all the devices that may need removing.
399 */
400static int handle_eject_request(struct dock_station *ds, u32 event)
401{
402	if (dock_in_progress(ds))
403		return -EBUSY;
404
405	/*
406	 * here we need to generate the undock
407	 * event prior to actually doing the undock
408	 * so that the device struct still exists.
409	 * Also, even send the dock event if the
410	 * device is not present anymore
411	 */
412	dock_event(ds, event, UNDOCK_EVENT);
413
414	hot_remove_dock_devices(ds);
415	undock(ds);
416	acpi_evaluate_lck(ds->handle, 0);
417	acpi_evaluate_ej0(ds->handle);
418	if (dock_present(ds)) {
419		acpi_handle_err(ds->handle, "Unable to undock!\n");
420		return -EBUSY;
421	}
422	complete_undock(ds);
423	return 0;
424}
425
426/**
427 * dock_notify - Handle ACPI dock notification.
428 * @adev: Dock station's ACPI device object.
429 * @event: Event code.
430 *
431 * If we are notified to dock, then check to see if the dock is
432 * present and then dock.  Notify all drivers of the dock event,
433 * and then hotplug and devices that may need hotplugging.
434 */
435int dock_notify(struct acpi_device *adev, u32 event)
436{
437	acpi_handle handle = adev->handle;
438	struct dock_station *ds = find_dock_station(handle);
439	int surprise_removal = 0;
440
441	if (!ds)
442		return -ENODEV;
443
444	/*
445	 * According to acpi spec 3.0a, if a DEVICE_CHECK notification
446	 * is sent and _DCK is present, it is assumed to mean an undock
447	 * request.
448	 */
449	if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
450		event = ACPI_NOTIFY_EJECT_REQUEST;
451
452	/*
453	 * dock station: BUS_CHECK - docked or surprise removal
454	 *		 DEVICE_CHECK - undocked
455	 * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
456	 *
457	 * To simplify event handling, dock dependent device handler always
458	 * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
459	 * ACPI_NOTIFY_EJECT_REQUEST for removal
460	 */
461	switch (event) {
462	case ACPI_NOTIFY_BUS_CHECK:
463	case ACPI_NOTIFY_DEVICE_CHECK:
464		if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) {
465			begin_dock(ds);
466			dock(ds);
467			if (!dock_present(ds)) {
468				acpi_handle_err(handle, "Unable to dock!\n");
469				complete_dock(ds);
470				break;
471			}
472			hotplug_dock_devices(ds, event);
473			complete_dock(ds);
474			dock_event(ds, event, DOCK_EVENT);
475			acpi_evaluate_lck(ds->handle, 1);
476			acpi_update_all_gpes();
477			break;
478		}
479		if (dock_present(ds) || dock_in_progress(ds))
480			break;
481		/* This is a surprise removal */
482		surprise_removal = 1;
483		event = ACPI_NOTIFY_EJECT_REQUEST;
484		/* Fall back */
485		/* fall through */
486	case ACPI_NOTIFY_EJECT_REQUEST:
487		begin_undock(ds);
488		if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
489		   || surprise_removal)
490			handle_eject_request(ds, event);
491		else
492			dock_event(ds, event, UNDOCK_EVENT);
493		break;
494	}
495	return 0;
496}
497
498/*
499 * show_docked - read method for "docked" file in sysfs
500 */
501static ssize_t show_docked(struct device *dev,
502			   struct device_attribute *attr, char *buf)
503{
504	struct dock_station *dock_station = dev->platform_data;
505	struct acpi_device *adev = NULL;
506
507	acpi_bus_get_device(dock_station->handle, &adev);
508	return snprintf(buf, PAGE_SIZE, "%u\n", acpi_device_enumerated(adev));
509}
510static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
511
512/*
513 * show_flags - read method for flags file in sysfs
514 */
515static ssize_t show_flags(struct device *dev,
516			  struct device_attribute *attr, char *buf)
517{
518	struct dock_station *dock_station = dev->platform_data;
519	return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
520
521}
522static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
523
524/*
525 * write_undock - write method for "undock" file in sysfs
526 */
527static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
528			   const char *buf, size_t count)
529{
530	int ret;
531	struct dock_station *dock_station = dev->platform_data;
532
533	if (!count)
534		return -EINVAL;
535
536	acpi_scan_lock_acquire();
537	begin_undock(dock_station);
538	ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
539	acpi_scan_lock_release();
540	return ret ? ret: count;
541}
542static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
543
544/*
545 * show_dock_uid - read method for "uid" file in sysfs
546 */
547static ssize_t show_dock_uid(struct device *dev,
548			     struct device_attribute *attr, char *buf)
549{
550	unsigned long long lbuf;
551	struct dock_station *dock_station = dev->platform_data;
552	acpi_status status = acpi_evaluate_integer(dock_station->handle,
553					"_UID", NULL, &lbuf);
554	if (ACPI_FAILURE(status))
555	    return 0;
556
557	return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf);
558}
559static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
560
561static ssize_t show_dock_type(struct device *dev,
562		struct device_attribute *attr, char *buf)
563{
564	struct dock_station *dock_station = dev->platform_data;
565	char *type;
566
567	if (dock_station->flags & DOCK_IS_DOCK)
568		type = "dock_station";
569	else if (dock_station->flags & DOCK_IS_ATA)
570		type = "ata_bay";
571	else if (dock_station->flags & DOCK_IS_BAT)
572		type = "battery_bay";
573	else
574		type = "unknown";
575
576	return snprintf(buf, PAGE_SIZE, "%s\n", type);
577}
578static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
579
580static struct attribute *dock_attributes[] = {
581	&dev_attr_docked.attr,
582	&dev_attr_flags.attr,
583	&dev_attr_undock.attr,
584	&dev_attr_uid.attr,
585	&dev_attr_type.attr,
586	NULL
587};
588
589static const struct attribute_group dock_attribute_group = {
590	.attrs = dock_attributes
591};
592
593/**
594 * acpi_dock_add - Add a new dock station
595 * @adev: Dock station ACPI device object.
596 *
597 * allocated and initialize a new dock station device.
598 */
599void acpi_dock_add(struct acpi_device *adev)
600{
601	struct dock_station *dock_station, ds = { NULL, };
602	struct platform_device_info pdevinfo;
603	acpi_handle handle = adev->handle;
604	struct platform_device *dd;
605	int ret;
606
607	memset(&pdevinfo, 0, sizeof(pdevinfo));
608	pdevinfo.name = "dock";
609	pdevinfo.id = dock_station_count;
610	pdevinfo.fwnode = acpi_fwnode_handle(adev);
611	pdevinfo.data = &ds;
612	pdevinfo.size_data = sizeof(ds);
613	dd = platform_device_register_full(&pdevinfo);
614	if (IS_ERR(dd))
615		return;
616
617	dock_station = dd->dev.platform_data;
618
619	dock_station->handle = handle;
620	dock_station->dock_device = dd;
621	dock_station->last_dock_time = jiffies - HZ;
622
623	INIT_LIST_HEAD(&dock_station->sibling);
624	INIT_LIST_HEAD(&dock_station->dependent_devices);
625
626	/* we want the dock device to send uevents */
627	dev_set_uevent_suppress(&dd->dev, 0);
628
629	if (acpi_dock_match(handle))
630		dock_station->flags |= DOCK_IS_DOCK;
631	if (acpi_ata_match(handle))
632		dock_station->flags |= DOCK_IS_ATA;
633	if (acpi_device_is_battery(adev))
634		dock_station->flags |= DOCK_IS_BAT;
635
636	ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
637	if (ret)
638		goto err_unregister;
639
640	/* add the dock station as a device dependent on itself */
641	ret = add_dock_dependent_device(dock_station, adev);
642	if (ret)
643		goto err_rmgroup;
644
645	dock_station_count++;
646	list_add(&dock_station->sibling, &dock_stations);
647	adev->flags.is_dock_station = true;
648	dev_info(&adev->dev, "ACPI dock station (docks/bays count: %d)\n",
649		 dock_station_count);
650	return;
651
652err_rmgroup:
653	sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
654
655err_unregister:
656	platform_device_unregister(dd);
657	acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
658}