2 * dock.c - ACPI dock station driver
4 * Copyright (C) 2006 Kristen Carlson Accardi <kristen.c.accardi@intel.com>
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
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.
22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 <linux/platform_device.h>
31 #include <linux/jiffies.h>
32 #include <linux/stddef.h>
33 #include <acpi/acpi_bus.h>
34 #include <acpi/acpi_drivers.h>
36 #define ACPI_DOCK_DRIVER_DESCRIPTION "ACPI Dock Station Driver"
38 ACPI_MODULE_NAME("dock");
39 MODULE_AUTHOR("Kristen Carlson Accardi");
40 MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_DESCRIPTION);
41 MODULE_LICENSE("GPL");
43 static int immediate_undock = 1;
44 module_param(immediate_undock, bool, 0644);
45 MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
46 "undock immediately when the undock button is pressed, 0 will cause"
47 " the driver to wait for userspace to write the undock sysfs file "
50 static struct atomic_notifier_head dock_notifier_list;
51 static struct platform_device *dock_device;
52 static char dock_device_name[] = "dock";
56 unsigned long last_dock_time;
60 struct list_head dependent_devices;
61 struct list_head hotplug_devices;
64 struct dock_dependent_device {
65 struct list_head list;
66 struct list_head hotplug_list;
68 acpi_notify_handler handler;
72 #define DOCK_DOCKING 0x00000001
73 #define DOCK_UNDOCKING 0x00000002
75 #define UNDOCK_EVENT 2
77 static struct dock_station *dock_station;
79 /*****************************************************************************
80 * Dock Dependent device functions *
81 *****************************************************************************/
83 * alloc_dock_dependent_device - allocate and init a dependent device
84 * @handle: the acpi_handle of the dependent device
86 * Allocate memory for a dependent device structure for a device referenced
89 static struct dock_dependent_device *
90 alloc_dock_dependent_device(acpi_handle handle)
92 struct dock_dependent_device *dd;
94 dd = kzalloc(sizeof(*dd), GFP_KERNEL);
97 INIT_LIST_HEAD(&dd->list);
98 INIT_LIST_HEAD(&dd->hotplug_list);
104 * add_dock_dependent_device - associate a device with the dock station
105 * @ds: The dock station
106 * @dd: The dependent device
108 * Add the dependent device to the dock's dependent device list.
111 add_dock_dependent_device(struct dock_station *ds,
112 struct dock_dependent_device *dd)
114 spin_lock(&ds->dd_lock);
115 list_add_tail(&dd->list, &ds->dependent_devices);
116 spin_unlock(&ds->dd_lock);
120 * dock_add_hotplug_device - associate a hotplug handler with the dock station
121 * @ds: The dock station
122 * @dd: The dependent device struct
124 * Add the dependent device to the dock's hotplug device list
127 dock_add_hotplug_device(struct dock_station *ds,
128 struct dock_dependent_device *dd)
130 mutex_lock(&ds->hp_lock);
131 list_add_tail(&dd->hotplug_list, &ds->hotplug_devices);
132 mutex_unlock(&ds->hp_lock);
136 * dock_del_hotplug_device - remove a hotplug handler from the dock station
137 * @ds: The dock station
138 * @dd: the dependent device struct
140 * Delete the dependent device from the dock's hotplug device list
143 dock_del_hotplug_device(struct dock_station *ds,
144 struct dock_dependent_device *dd)
146 mutex_lock(&ds->hp_lock);
147 list_del(&dd->hotplug_list);
148 mutex_unlock(&ds->hp_lock);
152 * find_dock_dependent_device - get a device dependent on this dock
153 * @ds: the dock station
154 * @handle: the acpi_handle of the device we want
156 * iterate over the dependent device list for this dock. If the
157 * dependent device matches the handle, return.
159 static struct dock_dependent_device *
160 find_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
162 struct dock_dependent_device *dd;
164 spin_lock(&ds->dd_lock);
165 list_for_each_entry(dd, &ds->dependent_devices, list) {
166 if (handle == dd->handle) {
167 spin_unlock(&ds->dd_lock);
171 spin_unlock(&ds->dd_lock);
175 /*****************************************************************************
177 *****************************************************************************/
179 * is_dock - see if a device is a dock station
180 * @handle: acpi handle of the device
182 * If an acpi object has a _DCK method, then it is by definition a dock
183 * station, so return true.
185 static int is_dock(acpi_handle handle)
190 status = acpi_get_handle(handle, "_DCK", &tmp);
191 if (ACPI_FAILURE(status))
197 * is_dock_device - see if a device is on a dock station
198 * @handle: acpi handle of the device
200 * If this device is either the dock station itself,
201 * or is a device dependent on the dock station, then it
204 int is_dock_device(acpi_handle handle)
209 if (is_dock(handle) || find_dock_dependent_device(dock_station, handle))
215 EXPORT_SYMBOL_GPL(is_dock_device);
218 * dock_present - see if the dock station is present.
219 * @ds: the dock station
221 * execute the _STA method. note that present does not
222 * imply that we are docked.
224 static int dock_present(struct dock_station *ds)
230 status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
231 if (ACPI_SUCCESS(status) && sta)
240 * dock_create_acpi_device - add new devices to acpi
241 * @handle - handle of the device to add
243 * This function will create a new acpi_device for the given
244 * handle if one does not exist already. This should cause
245 * acpi to scan for drivers for the given devices, and call
246 * matching driver's add routine.
248 * Returns a pointer to the acpi_device corresponding to the handle.
250 static struct acpi_device * dock_create_acpi_device(acpi_handle handle)
252 struct acpi_device *device = NULL;
253 struct acpi_device *parent_device;
257 if (acpi_bus_get_device(handle, &device)) {
259 * no device created for this object,
260 * so we should create one.
262 acpi_get_parent(handle, &parent);
263 if (acpi_bus_get_device(parent, &parent_device))
264 parent_device = NULL;
266 ret = acpi_bus_add(&device, parent_device, handle,
267 ACPI_BUS_TYPE_DEVICE);
269 pr_debug("error adding bus, %x\n",
278 * dock_remove_acpi_device - remove the acpi_device struct from acpi
279 * @handle - the handle of the device to remove
281 * Tell acpi to remove the acpi_device. This should cause any loaded
282 * driver to have it's remove routine called.
284 static void dock_remove_acpi_device(acpi_handle handle)
286 struct acpi_device *device;
289 if (!acpi_bus_get_device(handle, &device)) {
290 ret = acpi_bus_trim(device, 1);
292 pr_debug("error removing bus, %x\n", -ret);
298 * hotplug_dock_devices - insert or remove devices on the dock station
299 * @ds: the dock station
300 * @event: either bus check or eject request
302 * Some devices on the dock station need to have drivers called
303 * to perform hotplug operations after a dock event has occurred.
304 * Traverse the list of dock devices that have registered a
305 * hotplug handler, and call the handler.
307 static void hotplug_dock_devices(struct dock_station *ds, u32 event)
309 struct dock_dependent_device *dd;
311 mutex_lock(&ds->hp_lock);
314 * First call driver specific hotplug functions
316 list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list) {
318 dd->handler(dd->handle, event, dd->context);
322 * Now make sure that an acpi_device is created for each
323 * dependent device, or removed if this is an eject request.
324 * This will cause acpi_drivers to be stopped/started if they
327 list_for_each_entry(dd, &ds->dependent_devices, list) {
328 if (event == ACPI_NOTIFY_EJECT_REQUEST)
329 dock_remove_acpi_device(dd->handle);
331 dock_create_acpi_device(dd->handle);
333 mutex_unlock(&ds->hp_lock);
336 static void dock_event(struct dock_station *ds, u32 event, int num)
338 struct device *dev = &dock_device->dev;
340 * Indicate that the status of the dock station has
343 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
347 * eject_dock - respond to a dock eject request
348 * @ds: the dock station
350 * This is called after _DCK is called, to execute the dock station's
353 static void eject_dock(struct dock_station *ds)
355 struct acpi_object_list arg_list;
356 union acpi_object arg;
360 /* all dock devices should have _EJ0, but check anyway */
361 status = acpi_get_handle(ds->handle, "_EJ0", &tmp);
362 if (ACPI_FAILURE(status)) {
363 pr_debug("No _EJ0 support for dock device\n");
368 arg_list.pointer = &arg;
369 arg.type = ACPI_TYPE_INTEGER;
370 arg.integer.value = 1;
372 if (ACPI_FAILURE(acpi_evaluate_object(ds->handle, "_EJ0",
374 pr_debug("Failed to evaluate _EJ0!\n");
378 * handle_dock - handle a dock event
379 * @ds: the dock station
380 * @dock: to dock, or undock - that is the question
382 * Execute the _DCK method in response to an acpi event
384 static void handle_dock(struct dock_station *ds, int dock)
387 struct acpi_object_list arg_list;
388 union acpi_object arg;
389 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
390 struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL };
391 union acpi_object *obj;
393 acpi_get_name(ds->handle, ACPI_FULL_PATHNAME, &name_buffer);
394 obj = name_buffer.pointer;
396 printk(KERN_INFO PREFIX "%s\n", dock ? "docking" : "undocking");
398 /* _DCK method has one argument */
400 arg_list.pointer = &arg;
401 arg.type = ACPI_TYPE_INTEGER;
402 arg.integer.value = dock;
403 status = acpi_evaluate_object(ds->handle, "_DCK", &arg_list, &buffer);
404 if (ACPI_FAILURE(status))
405 pr_debug("%s: failed to execute _DCK\n", obj->string.pointer);
406 kfree(buffer.pointer);
407 kfree(name_buffer.pointer);
410 static inline void dock(struct dock_station *ds)
415 static inline void undock(struct dock_station *ds)
420 static inline void begin_dock(struct dock_station *ds)
422 ds->flags |= DOCK_DOCKING;
425 static inline void complete_dock(struct dock_station *ds)
427 ds->flags &= ~(DOCK_DOCKING);
428 ds->last_dock_time = jiffies;
431 static inline void begin_undock(struct dock_station *ds)
433 ds->flags |= DOCK_UNDOCKING;
436 static inline void complete_undock(struct dock_station *ds)
438 ds->flags &= ~(DOCK_UNDOCKING);
442 * dock_in_progress - see if we are in the middle of handling a dock event
443 * @ds: the dock station
445 * Sometimes while docking, false dock events can be sent to the driver
446 * because good connections aren't made or some other reason. Ignore these
447 * if we are in the middle of doing something.
449 static int dock_in_progress(struct dock_station *ds)
451 if ((ds->flags & DOCK_DOCKING) ||
452 time_before(jiffies, (ds->last_dock_time + HZ)))
458 * register_dock_notifier - add yourself to the dock notifier list
459 * @nb: the callers notifier block
461 * If a driver wishes to be notified about dock events, they can
462 * use this function to put a notifier block on the dock notifier list.
463 * this notifier call chain will be called after a dock event, but
464 * before hotplugging any new devices.
466 int register_dock_notifier(struct notifier_block *nb)
471 return atomic_notifier_chain_register(&dock_notifier_list, nb);
474 EXPORT_SYMBOL_GPL(register_dock_notifier);
477 * unregister_dock_notifier - remove yourself from the dock notifier list
478 * @nb: the callers notifier block
480 void unregister_dock_notifier(struct notifier_block *nb)
485 atomic_notifier_chain_unregister(&dock_notifier_list, nb);
488 EXPORT_SYMBOL_GPL(unregister_dock_notifier);
491 * register_hotplug_dock_device - register a hotplug function
492 * @handle: the handle of the device
493 * @handler: the acpi_notifier_handler to call after docking
494 * @context: device specific data
496 * If a driver would like to perform a hotplug operation after a dock
497 * event, they can register an acpi_notifiy_handler to be called by
498 * the dock driver after _DCK is executed.
501 register_hotplug_dock_device(acpi_handle handle, acpi_notify_handler handler,
504 struct dock_dependent_device *dd;
510 * make sure this handle is for a device dependent on the dock,
511 * this would include the dock station itself
513 dd = find_dock_dependent_device(dock_station, handle);
515 dd->handler = handler;
516 dd->context = context;
517 dock_add_hotplug_device(dock_station, dd);
524 EXPORT_SYMBOL_GPL(register_hotplug_dock_device);
527 * unregister_hotplug_dock_device - remove yourself from the hotplug list
528 * @handle: the acpi handle of the device
530 void unregister_hotplug_dock_device(acpi_handle handle)
532 struct dock_dependent_device *dd;
537 dd = find_dock_dependent_device(dock_station, handle);
539 dock_del_hotplug_device(dock_station, dd);
542 EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device);
545 * handle_eject_request - handle an undock request checking for error conditions
547 * Check to make sure the dock device is still present, then undock and
548 * hotremove all the devices that may need removing.
550 static int handle_eject_request(struct dock_station *ds, u32 event)
552 if (!dock_present(ds))
555 if (dock_in_progress(ds))
559 * here we need to generate the undock
560 * event prior to actually doing the undock
561 * so that the device struct still exists.
563 dock_event(ds, event, UNDOCK_EVENT);
564 hotplug_dock_devices(ds, ACPI_NOTIFY_EJECT_REQUEST);
567 if (dock_present(ds)) {
568 printk(KERN_ERR PREFIX "Unable to undock!\n");
576 * dock_notify - act upon an acpi dock notification
577 * @handle: the dock station handle
578 * @event: the acpi event
579 * @data: our driver data struct
581 * If we are notified to dock, then check to see if the dock is
582 * present and then dock. Notify all drivers of the dock event,
583 * and then hotplug and devices that may need hotplugging.
585 static void dock_notify(acpi_handle handle, u32 event, void *data)
587 struct dock_station *ds = data;
590 case ACPI_NOTIFY_BUS_CHECK:
591 if (!dock_in_progress(ds) && dock_present(ds)) {
594 if (!dock_present(ds)) {
595 printk(KERN_ERR PREFIX "Unable to dock!\n");
598 atomic_notifier_call_chain(&dock_notifier_list,
600 hotplug_dock_devices(ds, event);
602 dock_event(ds, event, DOCK_EVENT);
605 case ACPI_NOTIFY_DEVICE_CHECK:
607 * According to acpi spec 3.0a, if a DEVICE_CHECK notification
608 * is sent and _DCK is present, it is assumed to mean an
609 * undock request. This notify routine will only be called
610 * for objects defining _DCK, so we will fall through to eject
611 * request here. However, we will pass an eject request through
612 * to the driver who wish to hotplug.
614 case ACPI_NOTIFY_EJECT_REQUEST:
616 if (immediate_undock)
617 handle_eject_request(ds, event);
619 dock_event(ds, event, UNDOCK_EVENT);
622 printk(KERN_ERR PREFIX "Unknown dock event %d\n", event);
627 * find_dock_devices - find devices on the dock station
628 * @handle: the handle of the device we are examining
630 * @context: the dock station private data
633 * This function is called by acpi_walk_namespace. It will
634 * check to see if an object has an _EJD method. If it does, then it
635 * will see if it is dependent on the dock station.
638 find_dock_devices(acpi_handle handle, u32 lvl, void *context, void **rv)
641 acpi_handle tmp, parent;
642 struct dock_station *ds = context;
643 struct dock_dependent_device *dd;
645 status = acpi_bus_get_ejd(handle, &tmp);
646 if (ACPI_FAILURE(status)) {
647 /* try the parent device as well */
648 status = acpi_get_parent(handle, &parent);
649 if (ACPI_FAILURE(status))
651 /* see if parent is dependent on dock */
652 status = acpi_bus_get_ejd(parent, &tmp);
653 if (ACPI_FAILURE(status))
657 if (tmp == ds->handle) {
658 dd = alloc_dock_dependent_device(handle);
660 add_dock_dependent_device(ds, dd);
667 * show_docked - read method for "docked" file in sysfs
669 static ssize_t show_docked(struct device *dev,
670 struct device_attribute *attr, char *buf)
672 return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));
675 DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
678 * show_flags - read method for flags file in sysfs
680 static ssize_t show_flags(struct device *dev,
681 struct device_attribute *attr, char *buf)
683 return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
686 DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
689 * write_undock - write method for "undock" file in sysfs
691 static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
692 const char *buf, size_t count)
699 ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
700 return ret ? ret: count;
702 DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
705 * show_dock_uid - read method for "uid" file in sysfs
707 static ssize_t show_dock_uid(struct device *dev,
708 struct device_attribute *attr, char *buf)
711 acpi_status status = acpi_evaluate_integer(dock_station->handle,
712 "_UID", NULL, &lbuf);
713 if (ACPI_FAILURE(status))
716 return snprintf(buf, PAGE_SIZE, "%lx\n", lbuf);
718 DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
721 * dock_add - add a new dock station
722 * @handle: the dock station handle
724 * allocated and initialize a new dock station device. Find all devices
725 * that are on the dock station, and register for dock event notifications.
727 static int dock_add(acpi_handle handle)
731 struct dock_dependent_device *dd;
733 /* allocate & initialize the dock_station private data */
734 dock_station = kzalloc(sizeof(*dock_station), GFP_KERNEL);
737 dock_station->handle = handle;
738 dock_station->last_dock_time = jiffies - HZ;
739 INIT_LIST_HEAD(&dock_station->dependent_devices);
740 INIT_LIST_HEAD(&dock_station->hotplug_devices);
741 spin_lock_init(&dock_station->dd_lock);
742 mutex_init(&dock_station->hp_lock);
743 ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);
745 /* initialize platform device stuff */
747 platform_device_register_simple(dock_device_name, 0, NULL, 0);
748 if (IS_ERR(dock_device)) {
751 return PTR_ERR(dock_device);
754 ret = device_create_file(&dock_device->dev, &dev_attr_docked);
756 printk("Error %d adding sysfs file\n", ret);
757 platform_device_unregister(dock_device);
762 ret = device_create_file(&dock_device->dev, &dev_attr_undock);
764 printk("Error %d adding sysfs file\n", ret);
765 device_remove_file(&dock_device->dev, &dev_attr_docked);
766 platform_device_unregister(dock_device);
771 ret = device_create_file(&dock_device->dev, &dev_attr_uid);
773 printk("Error %d adding sysfs file\n", ret);
774 device_remove_file(&dock_device->dev, &dev_attr_docked);
775 device_remove_file(&dock_device->dev, &dev_attr_undock);
776 platform_device_unregister(dock_device);
781 ret = device_create_file(&dock_device->dev, &dev_attr_flags);
783 printk("Error %d adding sysfs file\n", ret);
784 device_remove_file(&dock_device->dev, &dev_attr_docked);
785 device_remove_file(&dock_device->dev, &dev_attr_undock);
786 device_remove_file(&dock_device->dev, &dev_attr_uid);
787 platform_device_unregister(dock_device);
793 /* Find dependent devices */
794 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
795 ACPI_UINT32_MAX, find_dock_devices, dock_station,
798 /* add the dock station as a device dependent on itself */
799 dd = alloc_dock_dependent_device(handle);
804 goto dock_add_err_unregister;
806 add_dock_dependent_device(dock_station, dd);
808 /* register for dock events */
809 status = acpi_install_notify_handler(dock_station->handle,
811 dock_notify, dock_station);
813 if (ACPI_FAILURE(status)) {
814 printk(KERN_ERR PREFIX "Error installing notify handler\n");
819 printk(KERN_INFO PREFIX "%s \n", ACPI_DOCK_DRIVER_DESCRIPTION);
825 dock_add_err_unregister:
826 device_remove_file(&dock_device->dev, &dev_attr_docked);
827 device_remove_file(&dock_device->dev, &dev_attr_undock);
828 device_remove_file(&dock_device->dev, &dev_attr_uid);
829 device_remove_file(&dock_device->dev, &dev_attr_flags);
830 platform_device_unregister(dock_device);
837 * dock_remove - free up resources related to the dock station
839 static int dock_remove(void)
841 struct dock_dependent_device *dd, *tmp;
847 /* remove dependent devices */
848 list_for_each_entry_safe(dd, tmp, &dock_station->dependent_devices,
852 /* remove dock notify handler */
853 status = acpi_remove_notify_handler(dock_station->handle,
856 if (ACPI_FAILURE(status))
857 printk(KERN_ERR "Error removing notify handler\n");
860 device_remove_file(&dock_device->dev, &dev_attr_docked);
861 device_remove_file(&dock_device->dev, &dev_attr_undock);
862 device_remove_file(&dock_device->dev, &dev_attr_uid);
863 device_remove_file(&dock_device->dev, &dev_attr_flags);
864 platform_device_unregister(dock_device);
866 /* free dock station memory */
873 * find_dock - look for a dock station
874 * @handle: acpi handle of a device
876 * @context: counter of dock stations found
879 * This is called by acpi_walk_namespace to look for dock stations.
882 find_dock(acpi_handle handle, u32 lvl, void *context, void **rv)
884 int *count = context;
885 acpi_status status = AE_OK;
887 if (is_dock(handle)) {
888 if (dock_add(handle) >= 0) {
890 status = AE_CTRL_TERMINATE;
896 static int __init dock_init(void)
902 /* look for a dock station */
903 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
904 ACPI_UINT32_MAX, find_dock, &num, NULL);
907 printk(KERN_INFO "No dock devices found.\n");
912 static void __exit dock_exit(void)
917 postcore_initcall(dock_init);
918 module_exit(dock_exit);