/* * 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 <linux/platform_device.h> #include <linux/jiffies.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; static struct platform_device dock_device; static char dock_device_name[] = "dock"; struct dock_station { acpi_handle handle; unsigned long last_dock_time; u32 flags; spinlock_t dd_lock; struct mutex 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 3 #define UNDOCK_EVENT 2 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) { mutex_lock(&ds->hp_lock); list_add_tail(&dd->hotplug_list, &ds->hotplug_devices); mutex_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) { mutex_lock(&ds->hp_lock); list_del(&dd->hotplug_list); mutex_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; mutex_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); } mutex_unlock(&ds->hp_lock); } static void dock_event(struct dock_station *ds, u32 event, int num) { struct device *dev = &dock_device.dev; /* * Indicate that the status of the dock station has * changed. */ kobject_uevent(&dev->kobj, KOBJ_CHANGE); } /** * 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) { if (!dock_station) return -ENODEV; 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) { if (!dock_station) return; 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); /** * handle_eject_request - handle an undock request checking for error conditions * * Check to make sure the dock device is still present, then undock and * hotremove all the devices that may need removing. */ static int handle_eject_request(struct dock_station *ds, u32 event) { if (!dock_present(ds)) return -ENODEV; if (dock_in_progress(ds)) return -EBUSY; /* * 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"); return -EBUSY; } return 0; } /** * 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. */ static void dock_notify(acpi_handle handle, u32 event, void *data) { struct dock_station *ds = 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: handle_eject_request(ds, event); 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, parent; struct dock_station *ds = context; struct dock_dependent_device *dd; status = acpi_bus_get_ejd(handle, &tmp); if (ACPI_FAILURE(status)) { /* try the parent device as well */ status = acpi_get_parent(handle, &parent); if (ACPI_FAILURE(status)) goto fdd_out; /* see if parent is dependent on dock */ status = acpi_bus_get_ejd(parent, &tmp); if (ACPI_FAILURE(status)) goto fdd_out; } if (tmp == ds->handle) { dd = alloc_dock_dependent_device(handle); if (dd) add_dock_dependent_device(ds, dd); } fdd_out: return AE_OK; } /* * show_docked - read method for "docked" file in sysfs */ static ssize_t show_docked(struct device *dev, struct device_attribute *attr, char *buf) { return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station)); } DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL); /* * write_undock - write method for "undock" file in sysfs */ static ssize_t write_undock(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int ret; if (!count) return -EINVAL; ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST); return ret ? ret: count; } DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock); /** * 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); mutex_init(&dock_station->hp_lock); ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list); /* initialize platform device stuff */ dock_device.name = dock_device_name; ret = platform_device_register(&dock_device); if (ret) { printk(KERN_ERR PREFIX "Error %d registering dock device\n", ret); kfree(dock_station); return ret; } ret = device_create_file(&dock_device.dev, &dev_attr_docked); if (ret) { printk("Error %d adding sysfs file\n", ret); platform_device_unregister(&dock_device); kfree(dock_station); return ret; } ret = device_create_file(&dock_device.dev, &dev_attr_undock); if (ret) { printk("Error %d adding sysfs file\n", ret); device_remove_file(&dock_device.dev, &dev_attr_docked); platform_device_unregister(&dock_device); kfree(dock_station); return ret; } /* 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); ret = -ENOMEM; goto dock_add_err_unregister; } 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(dd); dock_add_err_unregister: device_remove_file(&dock_device.dev, &dev_attr_docked); device_remove_file(&dock_device.dev, &dev_attr_undock); platform_device_unregister(&dock_device); kfree(dock_station); 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"); /* cleanup sysfs */ device_remove_file(&dock_device.dev, &dev_attr_docked); device_remove_file(&dock_device.dev, &dev_attr_undock); platform_device_unregister(&dock_device); /* 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 = 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) printk(KERN_INFO "No dock devices found.\n"); return 0; } static void __exit dock_exit(void) { dock_remove(); } postcore_initcall(dock_init); module_exit(dock_exit);