1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * dock.c - ACPI dock station driver
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>
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>
23 static bool immediate_undock = 1;
24 module_param(immediate_undock, bool, 0644);
25 MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
26 "undock immediately when the undock button is pressed, 0 will cause"
27 " the driver to wait for userspace to write the undock sysfs file "
32 unsigned long last_dock_time;
34 struct list_head dependent_devices;
36 struct list_head sibling;
37 struct platform_device *dock_device;
39 static LIST_HEAD(dock_stations);
40 static int dock_station_count;
42 struct dock_dependent_device {
43 struct list_head list;
44 struct acpi_device *adev;
47 #define DOCK_DOCKING 0x00000001
48 #define DOCK_UNDOCKING 0x00000002
49 #define DOCK_IS_DOCK 0x00000010
50 #define DOCK_IS_ATA 0x00000020
51 #define DOCK_IS_BAT 0x00000040
53 #define UNDOCK_EVENT 2
55 enum dock_callback_type {
61 /*****************************************************************************
62 * Dock Dependent device functions *
63 *****************************************************************************/
65 * add_dock_dependent_device - associate a device with the dock station
67 * @adev: Dependent ACPI device object.
69 * Add the dependent device to the dock's dependent device list.
71 static int add_dock_dependent_device(struct dock_station *ds,
72 struct acpi_device *adev)
74 struct dock_dependent_device *dd;
76 dd = kzalloc(sizeof(*dd), GFP_KERNEL);
81 INIT_LIST_HEAD(&dd->list);
82 list_add_tail(&dd->list, &ds->dependent_devices);
87 static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
88 enum dock_callback_type cb_type)
90 struct acpi_device *adev = dd->adev;
92 acpi_lock_hp_context();
97 if (cb_type == DOCK_CALL_FIXUP) {
98 void (*fixup)(struct acpi_device *);
100 fixup = adev->hp->fixup;
102 acpi_unlock_hp_context();
106 } else if (cb_type == DOCK_CALL_UEVENT) {
107 void (*uevent)(struct acpi_device *, u32);
109 uevent = adev->hp->uevent;
111 acpi_unlock_hp_context();
116 int (*notify)(struct acpi_device *, u32);
118 notify = adev->hp->notify;
120 acpi_unlock_hp_context();
127 acpi_unlock_hp_context();
130 static struct dock_station *find_dock_station(acpi_handle handle)
132 struct dock_station *ds;
134 list_for_each_entry(ds, &dock_stations, sibling)
135 if (ds->handle == handle)
142 * find_dock_dependent_device - get a device dependent on this dock
143 * @ds: the dock station
144 * @adev: ACPI device object to find.
146 * iterate over the dependent device list for this dock. If the
147 * dependent device matches the handle, return.
149 static struct dock_dependent_device *
150 find_dock_dependent_device(struct dock_station *ds, struct acpi_device *adev)
152 struct dock_dependent_device *dd;
154 list_for_each_entry(dd, &ds->dependent_devices, list)
155 if (adev == dd->adev)
161 void register_dock_dependent_device(struct acpi_device *adev,
162 acpi_handle dshandle)
164 struct dock_station *ds = find_dock_station(dshandle);
166 if (ds && !find_dock_dependent_device(ds, adev))
167 add_dock_dependent_device(ds, adev);
170 /*****************************************************************************
172 *****************************************************************************/
175 * is_dock_device - see if a device is on a dock station
176 * @adev: ACPI device object to check.
178 * If this device is either the dock station itself,
179 * or is a device dependent on the dock station, then it
182 int is_dock_device(struct acpi_device *adev)
184 struct dock_station *dock_station;
186 if (!dock_station_count)
189 if (acpi_dock_match(adev->handle))
192 list_for_each_entry(dock_station, &dock_stations, sibling)
193 if (find_dock_dependent_device(dock_station, adev))
198 EXPORT_SYMBOL_GPL(is_dock_device);
201 * dock_present - see if the dock station is present.
202 * @ds: the dock station
204 * execute the _STA method. note that present does not
205 * imply that we are docked.
207 static int dock_present(struct dock_station *ds)
209 unsigned long long sta;
213 status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
214 if (ACPI_SUCCESS(status) && sta)
221 * hot_remove_dock_devices - Remove dock station devices.
224 static void hot_remove_dock_devices(struct dock_station *ds)
226 struct dock_dependent_device *dd;
229 * Walk the list in reverse order so that devices that have been added
230 * last are removed first (in case there are some indirect dependencies
233 list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
234 dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST,
237 list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
238 acpi_bus_trim(dd->adev);
242 * hotplug_dock_devices - Insert devices on a dock station.
243 * @ds: the dock station
244 * @event: either bus check or device check request
246 * Some devices on the dock station need to have drivers called
247 * to perform hotplug operations after a dock event has occurred.
248 * Traverse the list of dock devices that have registered a
249 * hotplug handler, and call the handler.
251 static void hotplug_dock_devices(struct dock_station *ds, u32 event)
253 struct dock_dependent_device *dd;
255 /* Call driver specific post-dock fixups. */
256 list_for_each_entry(dd, &ds->dependent_devices, list)
257 dock_hotplug_event(dd, event, DOCK_CALL_FIXUP);
259 /* Call driver specific hotplug functions. */
260 list_for_each_entry(dd, &ds->dependent_devices, list)
261 dock_hotplug_event(dd, event, DOCK_CALL_HANDLER);
264 * Check if all devices have been enumerated already. If not, run
265 * acpi_bus_scan() for them and that will cause scan handlers to be
266 * attached to device objects or acpi_drivers to be stopped/started if
269 list_for_each_entry(dd, &ds->dependent_devices, list) {
270 struct acpi_device *adev = dd->adev;
272 if (!acpi_device_enumerated(adev)) {
273 int ret = acpi_bus_scan(adev->handle);
276 dev_dbg(&adev->dev, "scan error %d\n", -ret);
281 static void dock_event(struct dock_station *ds, u32 event, int num)
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;
288 if (num == UNDOCK_EVENT)
289 sprintf(event_string, "EVENT=undock");
291 sprintf(event_string, "EVENT=dock");
294 * Indicate that the status of the dock station has
297 if (num == DOCK_EVENT)
298 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
300 list_for_each_entry(dd, &ds->dependent_devices, list)
301 dock_hotplug_event(dd, event, DOCK_CALL_UEVENT);
303 if (num != DOCK_EVENT)
304 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
308 * handle_dock - handle a dock event
309 * @ds: the dock station
310 * @dock: to dock, or undock - that is the question
312 * Execute the _DCK method in response to an acpi event
314 static void handle_dock(struct dock_station *ds, int dock)
317 struct acpi_object_list arg_list;
318 union acpi_object arg;
319 unsigned long long value;
321 acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking");
323 /* _DCK method has one argument */
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",
334 static inline void dock(struct dock_station *ds)
339 static inline void undock(struct dock_station *ds)
344 static inline void begin_dock(struct dock_station *ds)
346 ds->flags |= DOCK_DOCKING;
349 static inline void complete_dock(struct dock_station *ds)
351 ds->flags &= ~(DOCK_DOCKING);
352 ds->last_dock_time = jiffies;
355 static inline void begin_undock(struct dock_station *ds)
357 ds->flags |= DOCK_UNDOCKING;
360 static inline void complete_undock(struct dock_station *ds)
362 ds->flags &= ~(DOCK_UNDOCKING);
366 * dock_in_progress - see if we are in the middle of handling a dock event
367 * @ds: the dock station
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.
373 static int dock_in_progress(struct dock_station *ds)
375 if ((ds->flags & DOCK_DOCKING) ||
376 time_before(jiffies, (ds->last_dock_time + HZ)))
382 * handle_eject_request - handle an undock request checking for error conditions
384 * Check to make sure the dock device is still present, then undock and
385 * hotremove all the devices that may need removing.
387 static int handle_eject_request(struct dock_station *ds, u32 event)
389 if (dock_in_progress(ds))
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
399 dock_event(ds, event, UNDOCK_EVENT);
401 hot_remove_dock_devices(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");
414 * dock_notify - Handle ACPI dock notification.
415 * @adev: Dock station's ACPI device object.
416 * @event: Event code.
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.
422 int dock_notify(struct acpi_device *adev, u32 event)
424 acpi_handle handle = adev->handle;
425 struct dock_station *ds = find_dock_station(handle);
426 int surprise_removal = 0;
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
436 if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
437 event = ACPI_NOTIFY_EJECT_REQUEST;
440 * dock station: BUS_CHECK - docked or surprise removal
441 * DEVICE_CHECK - undocked
442 * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
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
449 case ACPI_NOTIFY_BUS_CHECK:
450 case ACPI_NOTIFY_DEVICE_CHECK:
451 if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) {
454 if (!dock_present(ds)) {
455 acpi_handle_err(handle, "Unable to dock!\n");
459 hotplug_dock_devices(ds, event);
461 dock_event(ds, event, DOCK_EVENT);
462 acpi_evaluate_lck(ds->handle, 1);
463 acpi_update_all_gpes();
466 if (dock_present(ds) || dock_in_progress(ds))
468 /* This is a surprise removal */
469 surprise_removal = 1;
470 event = ACPI_NOTIFY_EJECT_REQUEST;
473 case ACPI_NOTIFY_EJECT_REQUEST:
475 if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
477 handle_eject_request(ds, event);
479 dock_event(ds, event, UNDOCK_EVENT);
486 * show_docked - read method for "docked" file in sysfs
488 static ssize_t docked_show(struct device *dev,
489 struct device_attribute *attr, char *buf)
491 struct dock_station *dock_station = dev->platform_data;
492 struct acpi_device *adev = NULL;
494 acpi_bus_get_device(dock_station->handle, &adev);
495 return snprintf(buf, PAGE_SIZE, "%u\n", acpi_device_enumerated(adev));
497 static DEVICE_ATTR_RO(docked);
500 * show_flags - read method for flags file in sysfs
502 static ssize_t flags_show(struct device *dev,
503 struct device_attribute *attr, char *buf)
505 struct dock_station *dock_station = dev->platform_data;
507 return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
510 static DEVICE_ATTR_RO(flags);
513 * write_undock - write method for "undock" file in sysfs
515 static ssize_t undock_store(struct device *dev, struct device_attribute *attr,
516 const char *buf, size_t count)
519 struct dock_station *dock_station = dev->platform_data;
524 acpi_scan_lock_acquire();
525 begin_undock(dock_station);
526 ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
527 acpi_scan_lock_release();
528 return ret ? ret : count;
530 static DEVICE_ATTR_WO(undock);
533 * show_dock_uid - read method for "uid" file in sysfs
535 static ssize_t uid_show(struct device *dev,
536 struct device_attribute *attr, char *buf)
538 unsigned long long lbuf;
539 struct dock_station *dock_station = dev->platform_data;
541 acpi_status status = acpi_evaluate_integer(dock_station->handle,
542 "_UID", NULL, &lbuf);
543 if (ACPI_FAILURE(status))
546 return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf);
548 static DEVICE_ATTR_RO(uid);
550 static ssize_t type_show(struct device *dev,
551 struct device_attribute *attr, char *buf)
553 struct dock_station *dock_station = dev->platform_data;
556 if (dock_station->flags & DOCK_IS_DOCK)
557 type = "dock_station";
558 else if (dock_station->flags & DOCK_IS_ATA)
560 else if (dock_station->flags & DOCK_IS_BAT)
561 type = "battery_bay";
565 return snprintf(buf, PAGE_SIZE, "%s\n", type);
567 static DEVICE_ATTR_RO(type);
569 static struct attribute *dock_attributes[] = {
570 &dev_attr_docked.attr,
571 &dev_attr_flags.attr,
572 &dev_attr_undock.attr,
578 static const struct attribute_group dock_attribute_group = {
579 .attrs = dock_attributes
583 * acpi_dock_add - Add a new dock station
584 * @adev: Dock station ACPI device object.
586 * allocated and initialize a new dock station device.
588 void acpi_dock_add(struct acpi_device *adev)
590 struct dock_station *dock_station, ds = { NULL, };
591 struct platform_device_info pdevinfo;
592 acpi_handle handle = adev->handle;
593 struct platform_device *dd;
596 memset(&pdevinfo, 0, sizeof(pdevinfo));
597 pdevinfo.name = "dock";
598 pdevinfo.id = dock_station_count;
599 pdevinfo.fwnode = acpi_fwnode_handle(adev);
601 pdevinfo.size_data = sizeof(ds);
602 dd = platform_device_register_full(&pdevinfo);
606 dock_station = dd->dev.platform_data;
608 dock_station->handle = handle;
609 dock_station->dock_device = dd;
610 dock_station->last_dock_time = jiffies - HZ;
612 INIT_LIST_HEAD(&dock_station->sibling);
613 INIT_LIST_HEAD(&dock_station->dependent_devices);
615 /* we want the dock device to send uevents */
616 dev_set_uevent_suppress(&dd->dev, 0);
618 if (acpi_dock_match(handle))
619 dock_station->flags |= DOCK_IS_DOCK;
620 if (acpi_ata_match(handle))
621 dock_station->flags |= DOCK_IS_ATA;
622 if (acpi_device_is_battery(adev))
623 dock_station->flags |= DOCK_IS_BAT;
625 ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
629 /* add the dock station as a device dependent on itself */
630 ret = add_dock_dependent_device(dock_station, adev);
634 dock_station_count++;
635 list_add(&dock_station->sibling, &dock_stations);
636 adev->flags.is_dock_station = true;
637 dev_info(&adev->dev, "ACPI dock station (docks/bays count: %d)\n",
642 sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
645 platform_device_unregister(dd);
646 acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);