diff options
Diffstat (limited to 'drivers/acpi/dock.c')
| -rw-r--r-- | drivers/acpi/dock.c | 740 |
1 files changed, 740 insertions, 0 deletions
diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c new file mode 100644 index 000000000000..1c0a39d8b04e --- /dev/null +++ b/drivers/acpi/dock.c @@ -0,0 +1,740 @@ +/* + * dock.c - ACPI dock station driver + * + * Copyright (C) 2006 Kristen Carlson Accardi <kristen.c.accardi@intel.com> + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/notifier.h> +#include <acpi/acpi_bus.h> +#include <acpi/acpi_drivers.h> + +#define ACPI_DOCK_DRIVER_NAME "ACPI Dock Station Driver" + +ACPI_MODULE_NAME("dock") +MODULE_AUTHOR("Kristen Carlson Accardi"); +MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_NAME); +MODULE_LICENSE("GPL"); + +static struct atomic_notifier_head dock_notifier_list; + +struct dock_station { + acpi_handle handle; + unsigned long last_dock_time; + u32 flags; + spinlock_t dd_lock; + spinlock_t hp_lock; + struct list_head dependent_devices; + struct list_head hotplug_devices; +}; + +struct dock_dependent_device { + struct list_head list; + struct list_head hotplug_list; + acpi_handle handle; + acpi_notify_handler handler; + void *context; +}; + +#define DOCK_DOCKING 0x00000001 +#define DOCK_EVENT KOBJ_DOCK +#define UNDOCK_EVENT KOBJ_UNDOCK + +static struct dock_station *dock_station; + +/***************************************************************************** + * Dock Dependent device functions * + *****************************************************************************/ +/** + * alloc_dock_dependent_device - allocate and init a dependent device + * @handle: the acpi_handle of the dependent device + * + * Allocate memory for a dependent device structure for a device referenced + * by the acpi handle + */ +static struct dock_dependent_device * +alloc_dock_dependent_device(acpi_handle handle) +{ + struct dock_dependent_device *dd; + + dd = kzalloc(sizeof(*dd), GFP_KERNEL); + if (dd) { + dd->handle = handle; + INIT_LIST_HEAD(&dd->list); + INIT_LIST_HEAD(&dd->hotplug_list); + } + return dd; +} + +/** + * add_dock_dependent_device - associate a device with the dock station + * @ds: The dock station + * @dd: The dependent device + * + * Add the dependent device to the dock's dependent device list. + */ +static void +add_dock_dependent_device(struct dock_station *ds, + struct dock_dependent_device *dd) +{ + spin_lock(&ds->dd_lock); + list_add_tail(&dd->list, &ds->dependent_devices); + spin_unlock(&ds->dd_lock); +} + +/** + * dock_add_hotplug_device - associate a hotplug handler with the dock station + * @ds: The dock station + * @dd: The dependent device struct + * + * Add the dependent device to the dock's hotplug device list + */ +static void +dock_add_hotplug_device(struct dock_station *ds, + struct dock_dependent_device *dd) +{ + spin_lock(&ds->hp_lock); + list_add_tail(&dd->hotplug_list, &ds->hotplug_devices); + spin_unlock(&ds->hp_lock); +} + +/** + * dock_del_hotplug_device - remove a hotplug handler from the dock station + * @ds: The dock station + * @dd: the dependent device struct + * + * Delete the dependent device from the dock's hotplug device list + */ +static void +dock_del_hotplug_device(struct dock_station *ds, + struct dock_dependent_device *dd) +{ + spin_lock(&ds->hp_lock); + list_del(&dd->hotplug_list); + spin_unlock(&ds->hp_lock); +} + +/** + * find_dock_dependent_device - get a device dependent on this dock + * @ds: the dock station + * @handle: the acpi_handle of the device we want + * + * iterate over the dependent device list for this dock. If the + * dependent device matches the handle, return. + */ +static struct dock_dependent_device * +find_dock_dependent_device(struct dock_station *ds, acpi_handle handle) +{ + struct dock_dependent_device *dd; + + spin_lock(&ds->dd_lock); + list_for_each_entry(dd, &ds->dependent_devices, list) { + if (handle == dd->handle) { + spin_unlock(&ds->dd_lock); + return dd; + } + } + spin_unlock(&ds->dd_lock); + return NULL; +} + +/***************************************************************************** + * Dock functions * + *****************************************************************************/ +/** + * is_dock - see if a device is a dock station + * @handle: acpi handle of the device + * + * If an acpi object has a _DCK method, then it is by definition a dock + * station, so return true. + */ +static int is_dock(acpi_handle handle) +{ + acpi_status status; + acpi_handle tmp; + + status = acpi_get_handle(handle, "_DCK", &tmp); + if (ACPI_FAILURE(status)) + return 0; + return 1; +} + +/** + * is_dock_device - see if a device is on a dock station + * @handle: acpi handle of the device + * + * If this device is either the dock station itself, + * or is a device dependent on the dock station, then it + * is a dock device + */ +int is_dock_device(acpi_handle handle) +{ + if (!dock_station) + return 0; + + if (is_dock(handle) || find_dock_dependent_device(dock_station, handle)) + return 1; + + return 0; +} + +EXPORT_SYMBOL_GPL(is_dock_device); + +/** + * dock_present - see if the dock station is present. + * @ds: the dock station + * + * execute the _STA method. note that present does not + * imply that we are docked. + */ +static int dock_present(struct dock_station *ds) +{ + unsigned long sta; + acpi_status status; + + if (ds) { + status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta); + if (ACPI_SUCCESS(status) && sta) + return 1; + } + return 0; +} + + + +/** + * dock_create_acpi_device - add new devices to acpi + * @handle - handle of the device to add + * + * This function will create a new acpi_device for the given + * handle if one does not exist already. This should cause + * acpi to scan for drivers for the given devices, and call + * matching driver's add routine. + * + * Returns a pointer to the acpi_device corresponding to the handle. + */ +static struct acpi_device * dock_create_acpi_device(acpi_handle handle) +{ + struct acpi_device *device = NULL; + struct acpi_device *parent_device; + acpi_handle parent; + int ret; + + if (acpi_bus_get_device(handle, &device)) { + /* + * no device created for this object, + * so we should create one. + */ + acpi_get_parent(handle, &parent); + if (acpi_bus_get_device(parent, &parent_device)) + parent_device = NULL; + + ret = acpi_bus_add(&device, parent_device, handle, + ACPI_BUS_TYPE_DEVICE); + if (ret) { + pr_debug("error adding bus, %x\n", + -ret); + return NULL; + } + } + return device; +} + +/** + * dock_remove_acpi_device - remove the acpi_device struct from acpi + * @handle - the handle of the device to remove + * + * Tell acpi to remove the acpi_device. This should cause any loaded + * driver to have it's remove routine called. + */ +static void dock_remove_acpi_device(acpi_handle handle) +{ + struct acpi_device *device; + int ret; + + if (!acpi_bus_get_device(handle, &device)) { + ret = acpi_bus_trim(device, 1); + if (ret) + pr_debug("error removing bus, %x\n", -ret); + } +} + + +/** + * hotplug_dock_devices - insert or remove devices on the dock station + * @ds: the dock station + * @event: either bus check or eject request + * + * Some devices on the dock station need to have drivers called + * to perform hotplug operations after a dock event has occurred. + * Traverse the list of dock devices that have registered a + * hotplug handler, and call the handler. + */ +static void hotplug_dock_devices(struct dock_station *ds, u32 event) +{ + struct dock_dependent_device *dd; + + spin_lock(&ds->hp_lock); + + /* + * First call driver specific hotplug functions + */ + list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list) { + if (dd->handler) + dd->handler(dd->handle, event, dd->context); + } + + /* + * Now make sure that an acpi_device is created for each + * dependent device, or removed if this is an eject request. + * This will cause acpi_drivers to be stopped/started if they + * exist + */ + list_for_each_entry(dd, &ds->dependent_devices, list) { + if (event == ACPI_NOTIFY_EJECT_REQUEST) + dock_remove_acpi_device(dd->handle); + else + dock_create_acpi_device(dd->handle); + } + spin_unlock(&ds->hp_lock); +} + +static void dock_event(struct dock_station *ds, u32 event, int num) +{ + struct acpi_device *device; + + device = dock_create_acpi_device(ds->handle); + if (device) + kobject_uevent(&device->kobj, num); +} + +/** + * eject_dock - respond to a dock eject request + * @ds: the dock station + * + * This is called after _DCK is called, to execute the dock station's + * _EJ0 method. + */ +static void eject_dock(struct dock_station *ds) +{ + struct acpi_object_list arg_list; + union acpi_object arg; + acpi_status status; + acpi_handle tmp; + + /* all dock devices should have _EJ0, but check anyway */ + status = acpi_get_handle(ds->handle, "_EJ0", &tmp); + if (ACPI_FAILURE(status)) { + pr_debug("No _EJ0 support for dock device\n"); + return; + } + + arg_list.count = 1; + arg_list.pointer = &arg; + arg.type = ACPI_TYPE_INTEGER; + arg.integer.value = 1; + + if (ACPI_FAILURE(acpi_evaluate_object(ds->handle, "_EJ0", + &arg_list, NULL))) + pr_debug("Failed to evaluate _EJ0!\n"); +} + +/** + * handle_dock - handle a dock event + * @ds: the dock station + * @dock: to dock, or undock - that is the question + * + * Execute the _DCK method in response to an acpi event + */ +static void handle_dock(struct dock_station *ds, int dock) +{ + acpi_status status; + struct acpi_object_list arg_list; + union acpi_object arg; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object *obj; + + acpi_get_name(ds->handle, ACPI_FULL_PATHNAME, &name_buffer); + obj = name_buffer.pointer; + + printk(KERN_INFO PREFIX "%s\n", dock ? "docking" : "undocking"); + + /* _DCK method has one argument */ + arg_list.count = 1; + arg_list.pointer = &arg; + arg.type = ACPI_TYPE_INTEGER; + arg.integer.value = dock; + status = acpi_evaluate_object(ds->handle, "_DCK", &arg_list, &buffer); + if (ACPI_FAILURE(status)) + pr_debug("%s: failed to execute _DCK\n", obj->string.pointer); + kfree(buffer.pointer); + kfree(name_buffer.pointer); +} + +static inline void dock(struct dock_station *ds) +{ + handle_dock(ds, 1); +} + +static inline void undock(struct dock_station *ds) +{ + handle_dock(ds, 0); +} + +static inline void begin_dock(struct dock_station *ds) +{ + ds->flags |= DOCK_DOCKING; +} + +static inline void complete_dock(struct dock_station *ds) +{ + ds->flags &= ~(DOCK_DOCKING); + ds->last_dock_time = jiffies; +} + +/** + * dock_in_progress - see if we are in the middle of handling a dock event + * @ds: the dock station + * + * Sometimes while docking, false dock events can be sent to the driver + * because good connections aren't made or some other reason. Ignore these + * if we are in the middle of doing something. + */ +static int dock_in_progress(struct dock_station *ds) +{ + if ((ds->flags & DOCK_DOCKING) || + time_before(jiffies, (ds->last_dock_time + HZ))) + return 1; + return 0; +} + +/** + * register_dock_notifier - add yourself to the dock notifier list + * @nb: the callers notifier block + * + * If a driver wishes to be notified about dock events, they can + * use this function to put a notifier block on the dock notifier list. + * this notifier call chain will be called after a dock event, but + * before hotplugging any new devices. + */ +int register_dock_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_register(&dock_notifier_list, nb); +} + +EXPORT_SYMBOL_GPL(register_dock_notifier); + +/** + * unregister_dock_notifier - remove yourself from the dock notifier list + * @nb: the callers notifier block + */ +void unregister_dock_notifier(struct notifier_block *nb) +{ + atomic_notifier_chain_unregister(&dock_notifier_list, nb); +} + +EXPORT_SYMBOL_GPL(unregister_dock_notifier); + +/** + * register_hotplug_dock_device - register a hotplug function + * @handle: the handle of the device + * @handler: the acpi_notifier_handler to call after docking + * @context: device specific data + * + * If a driver would like to perform a hotplug operation after a dock + * event, they can register an acpi_notifiy_handler to be called by + * the dock driver after _DCK is executed. + */ +int +register_hotplug_dock_device(acpi_handle handle, acpi_notify_handler handler, + void *context) +{ + struct dock_dependent_device *dd; + + if (!dock_station) + return -ENODEV; + + /* + * make sure this handle is for a device dependent on the dock, + * this would include the dock station itself + */ + dd = find_dock_dependent_device(dock_station, handle); + if (dd) { + dd->handler = handler; + dd->context = context; + dock_add_hotplug_device(dock_station, dd); + return 0; + } + + return -EINVAL; +} + +EXPORT_SYMBOL_GPL(register_hotplug_dock_device); + +/** + * unregister_hotplug_dock_device - remove yourself from the hotplug list + * @handle: the acpi handle of the device + */ +void unregister_hotplug_dock_device(acpi_handle handle) +{ + struct dock_dependent_device *dd; + + if (!dock_station) + return; + + dd = find_dock_dependent_device(dock_station, handle); + if (dd) + dock_del_hotplug_device(dock_station, dd); +} + +EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device); + +/** + * dock_notify - act upon an acpi dock notification + * @handle: the dock station handle + * @event: the acpi event + * @data: our driver data struct + * + * If we are notified to dock, then check to see if the dock is + * present and then dock. Notify all drivers of the dock event, + * and then hotplug and devices that may need hotplugging. For undock + * check to make sure the dock device is still present, then undock + * and hotremove all the devices that may need removing. + */ +static void dock_notify(acpi_handle handle, u32 event, void *data) +{ + struct dock_station *ds = (struct dock_station *)data; + + switch (event) { + case ACPI_NOTIFY_BUS_CHECK: + if (!dock_in_progress(ds) && dock_present(ds)) { + begin_dock(ds); + dock(ds); + if (!dock_present(ds)) { + printk(KERN_ERR PREFIX "Unable to dock!\n"); + break; + } + atomic_notifier_call_chain(&dock_notifier_list, + event, NULL); + hotplug_dock_devices(ds, event); + complete_dock(ds); + dock_event(ds, event, DOCK_EVENT); + } + break; + case ACPI_NOTIFY_DEVICE_CHECK: + /* + * According to acpi spec 3.0a, if a DEVICE_CHECK notification + * is sent and _DCK is present, it is assumed to mean an + * undock request. This notify routine will only be called + * for objects defining _DCK, so we will fall through to eject + * request here. However, we will pass an eject request through + * to the driver who wish to hotplug. + */ + case ACPI_NOTIFY_EJECT_REQUEST: + if (!dock_in_progress(ds) && dock_present(ds)) { + /* + * here we need to generate the undock + * event prior to actually doing the undock + * so that the device struct still exists. + */ + dock_event(ds, event, UNDOCK_EVENT); + hotplug_dock_devices(ds, ACPI_NOTIFY_EJECT_REQUEST); + undock(ds); + eject_dock(ds); + if (dock_present(ds)) + printk(KERN_ERR PREFIX "Unable to undock!\n"); + } + break; + default: + printk(KERN_ERR PREFIX "Unknown dock event %d\n", event); + } +} + +/** + * find_dock_devices - find devices on the dock station + * @handle: the handle of the device we are examining + * @lvl: unused + * @context: the dock station private data + * @rv: unused + * + * This function is called by acpi_walk_namespace. It will + * check to see if an object has an _EJD method. If it does, then it + * will see if it is dependent on the dock station. + */ +static acpi_status +find_dock_devices(acpi_handle handle, u32 lvl, void *context, void **rv) +{ + acpi_status status; + acpi_handle tmp; + struct dock_station *ds = (struct dock_station *)context; + struct dock_dependent_device *dd; + + status = acpi_bus_get_ejd(handle, &tmp); + if (ACPI_FAILURE(status)) + return AE_OK; + + if (tmp == ds->handle) { + dd = alloc_dock_dependent_device(handle); + if (dd) + add_dock_dependent_device(ds, dd); + } + + return AE_OK; +} + +/** + * dock_add - add a new dock station + * @handle: the dock station handle + * + * allocated and initialize a new dock station device. Find all devices + * that are on the dock station, and register for dock event notifications. + */ +static int dock_add(acpi_handle handle) +{ + int ret; + acpi_status status; + struct dock_dependent_device *dd; + + /* allocate & initialize the dock_station private data */ + dock_station = kzalloc(sizeof(*dock_station), GFP_KERNEL); + if (!dock_station) + return -ENOMEM; + dock_station->handle = handle; + dock_station->last_dock_time = jiffies - HZ; + INIT_LIST_HEAD(&dock_station->dependent_devices); + INIT_LIST_HEAD(&dock_station->hotplug_devices); + spin_lock_init(&dock_station->dd_lock); + spin_lock_init(&dock_station->hp_lock); + ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list); + + /* Find dependent devices */ + acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, + ACPI_UINT32_MAX, find_dock_devices, dock_station, + NULL); + + /* add the dock station as a device dependent on itself */ + dd = alloc_dock_dependent_device(handle); + if (!dd) { + kfree(dock_station); + return -ENOMEM; + } + add_dock_dependent_device(dock_station, dd); + + /* register for dock events */ + status = acpi_install_notify_handler(dock_station->handle, + ACPI_SYSTEM_NOTIFY, + dock_notify, dock_station); + + if (ACPI_FAILURE(status)) { + printk(KERN_ERR PREFIX "Error installing notify handler\n"); + ret = -ENODEV; + goto dock_add_err; + } + + printk(KERN_INFO PREFIX "%s \n", ACPI_DOCK_DRIVER_NAME); + + return 0; + +dock_add_err: + kfree(dock_station); + kfree(dd); + return ret; +} + +/** + * dock_remove - free up resources related to the dock station + */ +static int dock_remove(void) +{ + struct dock_dependent_device *dd, *tmp; + acpi_status status; + + if (!dock_station) + return 0; + + /* remove dependent devices */ + list_for_each_entry_safe(dd, tmp, &dock_station->dependent_devices, + list) + kfree(dd); + + /* remove dock notify handler */ + status = acpi_remove_notify_handler(dock_station->handle, + ACPI_SYSTEM_NOTIFY, + dock_notify); + if (ACPI_FAILURE(status)) + printk(KERN_ERR "Error removing notify handler\n"); + + /* free dock station memory */ + kfree(dock_station); + return 0; +} + +/** + * find_dock - look for a dock station + * @handle: acpi handle of a device + * @lvl: unused + * @context: counter of dock stations found + * @rv: unused + * + * This is called by acpi_walk_namespace to look for dock stations. + */ +static acpi_status +find_dock(acpi_handle handle, u32 lvl, void *context, void **rv) +{ + int *count = (int *)context; + acpi_status status = AE_OK; + + if (is_dock(handle)) { + if (dock_add(handle) >= 0) { + (*count)++; + status = AE_CTRL_TERMINATE; + } + } + return status; +} + +static int __init dock_init(void) +{ + int num = 0; + + dock_station = NULL; + + /* look for a dock station */ + acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, + ACPI_UINT32_MAX, find_dock, &num, NULL); + + if (!num) + return -ENODEV; + + return 0; +} + +static void __exit dock_exit(void) +{ + dock_remove(); +} + +postcore_initcall(dock_init); +module_exit(dock_exit); |