--- /dev/null
+/*
+ * 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);
+
+ /* 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);
projects / linux-2.6 / commitdiff