/* * Universal power supply monitor class * * Copyright © 2007 Anton Vorontsov * Copyright © 2004 Szabolcs Gyurko * Copyright © 2003 Ian Molton * * Modified: 2004, Oct Szabolcs Gyurko * * You may use this code as per GPL version 2 */ #include #include #include #include #include #include #include #include #include #include "power_supply.h" /* exported for the APM Power driver, APM emulation */ struct class *power_supply_class; EXPORT_SYMBOL_GPL(power_supply_class); ATOMIC_NOTIFIER_HEAD(power_supply_notifier); EXPORT_SYMBOL_GPL(power_supply_notifier); static struct device_type power_supply_dev_type; #define POWER_SUPPLY_DEFERRED_REGISTER_TIME msecs_to_jiffies(10) static bool __power_supply_is_supplied_by(struct power_supply *supplier, struct power_supply *supply) { int i; if (!supply->supplied_from && !supplier->supplied_to) return false; /* Support both supplied_to and supplied_from modes */ if (supply->supplied_from) { if (!supplier->desc->name) return false; for (i = 0; i < supply->num_supplies; i++) if (!strcmp(supplier->desc->name, supply->supplied_from[i])) return true; } else { if (!supply->desc->name) return false; for (i = 0; i < supplier->num_supplicants; i++) if (!strcmp(supplier->supplied_to[i], supply->desc->name)) return true; } return false; } static int __power_supply_changed_work(struct device *dev, void *data) { struct power_supply *psy = data; struct power_supply *pst = dev_get_drvdata(dev); if (__power_supply_is_supplied_by(psy, pst)) { if (pst->desc->external_power_changed) pst->desc->external_power_changed(pst); } return 0; } static void power_supply_changed_work(struct work_struct *work) { unsigned long flags; struct power_supply *psy = container_of(work, struct power_supply, changed_work); dev_dbg(&psy->dev, "%s\n", __func__); spin_lock_irqsave(&psy->changed_lock, flags); /* * Check 'changed' here to avoid issues due to race between * power_supply_changed() and this routine. In worst case * power_supply_changed() can be called again just before we take above * lock. During the first call of this routine we will mark 'changed' as * false and it will stay false for the next call as well. */ if (likely(psy->changed)) { psy->changed = false; spin_unlock_irqrestore(&psy->changed_lock, flags); class_for_each_device(power_supply_class, NULL, psy, __power_supply_changed_work); power_supply_update_leds(psy); atomic_notifier_call_chain(&power_supply_notifier, PSY_EVENT_PROP_CHANGED, psy); kobject_uevent(&psy->dev.kobj, KOBJ_CHANGE); spin_lock_irqsave(&psy->changed_lock, flags); } /* * Hold the wakeup_source until all events are processed. * power_supply_changed() might have called again and have set 'changed' * to true. */ if (likely(!psy->changed)) pm_relax(&psy->dev); spin_unlock_irqrestore(&psy->changed_lock, flags); } void power_supply_changed(struct power_supply *psy) { unsigned long flags; dev_dbg(&psy->dev, "%s\n", __func__); spin_lock_irqsave(&psy->changed_lock, flags); psy->changed = true; pm_stay_awake(&psy->dev); spin_unlock_irqrestore(&psy->changed_lock, flags); schedule_work(&psy->changed_work); } EXPORT_SYMBOL_GPL(power_supply_changed); /* * Notify that power supply was registered after parent finished the probing. * * Often power supply is registered from driver's probe function. However * calling power_supply_changed() directly from power_supply_register() * would lead to execution of get_property() function provided by the driver * too early - before the probe ends. * * Avoid that by waiting on parent's mutex. */ static void power_supply_deferred_register_work(struct work_struct *work) { struct power_supply *psy = container_of(work, struct power_supply, deferred_register_work.work); if (psy->dev.parent) mutex_lock(&psy->dev.parent->mutex); power_supply_changed(psy); if (psy->dev.parent) mutex_unlock(&psy->dev.parent->mutex); } #ifdef CONFIG_OF #include static int __power_supply_populate_supplied_from(struct device *dev, void *data) { struct power_supply *psy = data; struct power_supply *epsy = dev_get_drvdata(dev); struct device_node *np; int i = 0; do { np = of_parse_phandle(psy->of_node, "power-supplies", i++); if (!np) break; if (np == epsy->of_node) { dev_info(&psy->dev, "%s: Found supply : %s\n", psy->desc->name, epsy->desc->name); psy->supplied_from[i-1] = (char *)epsy->desc->name; psy->num_supplies++; of_node_put(np); break; } of_node_put(np); } while (np); return 0; } static int power_supply_populate_supplied_from(struct power_supply *psy) { int error; error = class_for_each_device(power_supply_class, NULL, psy, __power_supply_populate_supplied_from); dev_dbg(&psy->dev, "%s %d\n", __func__, error); return error; } static int __power_supply_find_supply_from_node(struct device *dev, void *data) { struct device_node *np = data; struct power_supply *epsy = dev_get_drvdata(dev); /* returning non-zero breaks out of class_for_each_device loop */ if (epsy->of_node == np) return 1; return 0; } static int power_supply_find_supply_from_node(struct device_node *supply_node) { int error; /* * class_for_each_device() either returns its own errors or values * returned by __power_supply_find_supply_from_node(). * * __power_supply_find_supply_from_node() will return 0 (no match) * or 1 (match). * * We return 0 if class_for_each_device() returned 1, -EPROBE_DEFER if * it returned 0, or error as returned by it. */ error = class_for_each_device(power_supply_class, NULL, supply_node, __power_supply_find_supply_from_node); return error ? (error == 1 ? 0 : error) : -EPROBE_DEFER; } static int power_supply_check_supplies(struct power_supply *psy) { struct device_node *np; int cnt = 0; /* If there is already a list honor it */ if (psy->supplied_from && psy->num_supplies > 0) return 0; /* No device node found, nothing to do */ if (!psy->of_node) return 0; do { int ret; np = of_parse_phandle(psy->of_node, "power-supplies", cnt++); if (!np) break; ret = power_supply_find_supply_from_node(np); of_node_put(np); if (ret) { dev_dbg(&psy->dev, "Failed to find supply!\n"); return ret; } } while (np); /* Missing valid "power-supplies" entries */ if (cnt == 1) return 0; /* All supplies found, allocate char ** array for filling */ psy->supplied_from = devm_kzalloc(&psy->dev, sizeof(psy->supplied_from), GFP_KERNEL); if (!psy->supplied_from) { dev_err(&psy->dev, "Couldn't allocate memory for supply list\n"); return -ENOMEM; } *psy->supplied_from = devm_kzalloc(&psy->dev, sizeof(char *) * (cnt - 1), GFP_KERNEL); if (!*psy->supplied_from) { dev_err(&psy->dev, "Couldn't allocate memory for supply list\n"); return -ENOMEM; } return power_supply_populate_supplied_from(psy); } #else static inline int power_supply_check_supplies(struct power_supply *psy) { return 0; } #endif static int __power_supply_am_i_supplied(struct device *dev, void *data) { union power_supply_propval ret = {0,}; struct power_supply *psy = data; struct power_supply *epsy = dev_get_drvdata(dev); if (__power_supply_is_supplied_by(epsy, psy)) if (!epsy->desc->get_property(epsy, POWER_SUPPLY_PROP_ONLINE, &ret)) return ret.intval; return 0; } int power_supply_am_i_supplied(struct power_supply *psy) { int error; error = class_for_each_device(power_supply_class, NULL, psy, __power_supply_am_i_supplied); dev_dbg(&psy->dev, "%s %d\n", __func__, error); return error; } EXPORT_SYMBOL_GPL(power_supply_am_i_supplied); static int __power_supply_is_system_supplied(struct device *dev, void *data) { union power_supply_propval ret = {0,}; struct power_supply *psy = dev_get_drvdata(dev); unsigned int *count = data; (*count)++; if (psy->desc->type != POWER_SUPPLY_TYPE_BATTERY) if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret)) return ret.intval; return 0; } int power_supply_is_system_supplied(void) { int error; unsigned int count = 0; error = class_for_each_device(power_supply_class, NULL, &count, __power_supply_is_system_supplied); /* * If no power class device was found at all, most probably we are * running on a desktop system, so assume we are on mains power. */ if (count == 0) return 1; return error; } EXPORT_SYMBOL_GPL(power_supply_is_system_supplied); int power_supply_set_battery_charged(struct power_supply *psy) { if (atomic_read(&psy->use_cnt) >= 0 && psy->desc->type == POWER_SUPPLY_TYPE_BATTERY && psy->desc->set_charged) { psy->desc->set_charged(psy); return 0; } return -EINVAL; } EXPORT_SYMBOL_GPL(power_supply_set_battery_charged); static int power_supply_match_device_by_name(struct device *dev, const void *data) { const char *name = data; struct power_supply *psy = dev_get_drvdata(dev); return strcmp(psy->desc->name, name) == 0; } /** * power_supply_get_by_name() - Search for a power supply and returns its ref * @name: Power supply name to fetch * * If power supply was found, it increases reference count for the * internal power supply's device. The user should power_supply_put() * after usage. * * Return: On success returns a reference to a power supply with * matching name equals to @name, a NULL otherwise. */ struct power_supply *power_supply_get_by_name(const char *name) { struct power_supply *psy = NULL; struct device *dev = class_find_device(power_supply_class, NULL, name, power_supply_match_device_by_name); if (dev) { psy = dev_get_drvdata(dev); atomic_inc(&psy->use_cnt); } return psy; } EXPORT_SYMBOL_GPL(power_supply_get_by_name); /** * power_supply_put() - Drop reference obtained with power_supply_get_by_name * @psy: Reference to put * * The reference to power supply should be put before unregistering * the power supply. */ void power_supply_put(struct power_supply *psy) { might_sleep(); atomic_dec(&psy->use_cnt); put_device(&psy->dev); } EXPORT_SYMBOL_GPL(power_supply_put); #ifdef CONFIG_OF static int power_supply_match_device_node(struct device *dev, const void *data) { return dev->parent && dev->parent->of_node == data; } /** * power_supply_get_by_phandle() - Search for a power supply and returns its ref * @np: Pointer to device node holding phandle property * @property: Name of property holding a power supply name * * If power supply was found, it increases reference count for the * internal power supply's device. The user should power_supply_put() * after usage. * * Return: On success returns a reference to a power supply with * matching name equals to value under @property, NULL or ERR_PTR otherwise. */ struct power_supply *power_supply_get_by_phandle(struct device_node *np, const char *property) { struct device_node *power_supply_np; struct power_supply *psy = NULL; struct device *dev; power_supply_np = of_parse_phandle(np, property, 0); if (!power_supply_np) return ERR_PTR(-ENODEV); dev = class_find_device(power_supply_class, NULL, power_supply_np, power_supply_match_device_node); of_node_put(power_supply_np); if (dev) { psy = dev_get_drvdata(dev); atomic_inc(&psy->use_cnt); } return psy; } EXPORT_SYMBOL_GPL(power_supply_get_by_phandle); static void devm_power_supply_put(struct device *dev, void *res) { struct power_supply **psy = res; power_supply_put(*psy); } /** * devm_power_supply_get_by_phandle() - Resource managed version of * power_supply_get_by_phandle() * @dev: Pointer to device holding phandle property * @property: Name of property holding a power supply phandle * * Return: On success returns a reference to a power supply with * matching name equals to value under @property, NULL or ERR_PTR otherwise. */ struct power_supply *devm_power_supply_get_by_phandle(struct device *dev, const char *property) { struct power_supply **ptr, *psy; if (!dev->of_node) return ERR_PTR(-ENODEV); ptr = devres_alloc(devm_power_supply_put, sizeof(*ptr), GFP_KERNEL); if (!ptr) return ERR_PTR(-ENOMEM); psy = power_supply_get_by_phandle(dev->of_node, property); if (IS_ERR_OR_NULL(psy)) { devres_free(ptr); } else { *ptr = psy; devres_add(dev, ptr); } return psy; } EXPORT_SYMBOL_GPL(devm_power_supply_get_by_phandle); #endif /* CONFIG_OF */ int power_supply_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { if (atomic_read(&psy->use_cnt) <= 0) { if (!psy->initialized) return -EAGAIN; return -ENODEV; } return psy->desc->get_property(psy, psp, val); } EXPORT_SYMBOL_GPL(power_supply_get_property); int power_supply_set_property(struct power_supply *psy, enum power_supply_property psp, const union power_supply_propval *val) { if (atomic_read(&psy->use_cnt) <= 0 || !psy->desc->set_property) return -ENODEV; return psy->desc->set_property(psy, psp, val); } EXPORT_SYMBOL_GPL(power_supply_set_property); int power_supply_property_is_writeable(struct power_supply *psy, enum power_supply_property psp) { if (atomic_read(&psy->use_cnt) <= 0 || !psy->desc->property_is_writeable) return -ENODEV; return psy->desc->property_is_writeable(psy, psp); } EXPORT_SYMBOL_GPL(power_supply_property_is_writeable); void power_supply_external_power_changed(struct power_supply *psy) { if (atomic_read(&psy->use_cnt) <= 0 || !psy->desc->external_power_changed) return; psy->desc->external_power_changed(psy); } EXPORT_SYMBOL_GPL(power_supply_external_power_changed); int power_supply_powers(struct power_supply *psy, struct device *dev) { return sysfs_create_link(&psy->dev.kobj, &dev->kobj, "powers"); } EXPORT_SYMBOL_GPL(power_supply_powers); static void power_supply_dev_release(struct device *dev) { struct power_supply *psy = container_of(dev, struct power_supply, dev); pr_debug("device: '%s': %s\n", dev_name(dev), __func__); kfree(psy); } int power_supply_reg_notifier(struct notifier_block *nb) { return atomic_notifier_chain_register(&power_supply_notifier, nb); } EXPORT_SYMBOL_GPL(power_supply_reg_notifier); void power_supply_unreg_notifier(struct notifier_block *nb) { atomic_notifier_chain_unregister(&power_supply_notifier, nb); } EXPORT_SYMBOL_GPL(power_supply_unreg_notifier); #ifdef CONFIG_THERMAL static int power_supply_read_temp(struct thermal_zone_device *tzd, int *temp) { struct power_supply *psy; union power_supply_propval val; int ret; WARN_ON(tzd == NULL); psy = tzd->devdata; ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_TEMP, &val); if (ret) return ret; /* Convert tenths of degree Celsius to milli degree Celsius. */ *temp = val.intval * 100; return ret; } static struct thermal_zone_device_ops psy_tzd_ops = { .get_temp = power_supply_read_temp, }; static int psy_register_thermal(struct power_supply *psy) { int i; if (psy->desc->no_thermal) return 0; /* Register battery zone device psy reports temperature */ for (i = 0; i < psy->desc->num_properties; i++) { if (psy->desc->properties[i] == POWER_SUPPLY_PROP_TEMP) { psy->tzd = thermal_zone_device_register(psy->desc->name, 0, 0, psy, &psy_tzd_ops, NULL, 0, 0); return PTR_ERR_OR_ZERO(psy->tzd); } } return 0; } static void psy_unregister_thermal(struct power_supply *psy) { if (IS_ERR_OR_NULL(psy->tzd)) return; thermal_zone_device_unregister(psy->tzd); } /* thermal cooling device callbacks */ static int ps_get_max_charge_cntl_limit(struct thermal_cooling_device *tcd, unsigned long *state) { struct power_supply *psy; union power_supply_propval val; int ret; psy = tcd->devdata; ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX, &val); if (ret) return ret; *state = val.intval; return ret; } static int ps_get_cur_chrage_cntl_limit(struct thermal_cooling_device *tcd, unsigned long *state) { struct power_supply *psy; union power_supply_propval val; int ret; psy = tcd->devdata; ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val); if (ret) return ret; *state = val.intval; return ret; } static int ps_set_cur_charge_cntl_limit(struct thermal_cooling_device *tcd, unsigned long state) { struct power_supply *psy; union power_supply_propval val; int ret; psy = tcd->devdata; val.intval = state; ret = psy->desc->set_property(psy, POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val); return ret; } static struct thermal_cooling_device_ops psy_tcd_ops = { .get_max_state = ps_get_max_charge_cntl_limit, .get_cur_state = ps_get_cur_chrage_cntl_limit, .set_cur_state = ps_set_cur_charge_cntl_limit, }; static int psy_register_cooler(struct power_supply *psy) { int i; /* Register for cooling device if psy can control charging */ for (i = 0; i < psy->desc->num_properties; i++) { if (psy->desc->properties[i] == POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT) { psy->tcd = thermal_cooling_device_register( (char *)psy->desc->name, psy, &psy_tcd_ops); return PTR_ERR_OR_ZERO(psy->tcd); } } return 0; } static void psy_unregister_cooler(struct power_supply *psy) { if (IS_ERR_OR_NULL(psy->tcd)) return; thermal_cooling_device_unregister(psy->tcd); } #else static int psy_register_thermal(struct power_supply *psy) { return 0; } static void psy_unregister_thermal(struct power_supply *psy) { } static int psy_register_cooler(struct power_supply *psy) { return 0; } static void psy_unregister_cooler(struct power_supply *psy) { } #endif static struct power_supply *__must_check __power_supply_register(struct device *parent, const struct power_supply_desc *desc, const struct power_supply_config *cfg, bool ws) { struct device *dev; struct power_supply *psy; int rc; if (!parent) pr_warn("%s: Expected proper parent device for '%s'\n", __func__, desc->name); psy = kzalloc(sizeof(*psy), GFP_KERNEL); if (!psy) return ERR_PTR(-ENOMEM); dev = &psy->dev; device_initialize(dev); dev->class = power_supply_class; dev->type = &power_supply_dev_type; dev->parent = parent; dev->release = power_supply_dev_release; dev_set_drvdata(dev, psy); psy->desc = desc; if (cfg) { psy->drv_data = cfg->drv_data; psy->of_node = cfg->of_node; psy->supplied_to = cfg->supplied_to; psy->num_supplicants = cfg->num_supplicants; } rc = dev_set_name(dev, "%s", desc->name); if (rc) goto dev_set_name_failed; INIT_WORK(&psy->changed_work, power_supply_changed_work); INIT_DELAYED_WORK(&psy->deferred_register_work, power_supply_deferred_register_work); rc = power_supply_check_supplies(psy); if (rc) { dev_info(dev, "Not all required supplies found, defer probe\n"); goto check_supplies_failed; } spin_lock_init(&psy->changed_lock); rc = device_init_wakeup(dev, ws); if (rc) goto wakeup_init_failed; rc = device_add(dev); if (rc) goto device_add_failed; rc = psy_register_thermal(psy); if (rc) goto register_thermal_failed; rc = psy_register_cooler(psy); if (rc) goto register_cooler_failed; rc = power_supply_create_triggers(psy); if (rc) goto create_triggers_failed; /* * Update use_cnt after any uevents (most notably from device_add()). * We are here still during driver's probe but * the power_supply_uevent() calls back driver's get_property * method so: * 1. Driver did not assigned the returned struct power_supply, * 2. Driver could not finish initialization (anything in its probe * after calling power_supply_register()). */ atomic_inc(&psy->use_cnt); psy->initialized = true; queue_delayed_work(system_power_efficient_wq, &psy->deferred_register_work, POWER_SUPPLY_DEFERRED_REGISTER_TIME); return psy; create_triggers_failed: psy_unregister_cooler(psy); register_cooler_failed: psy_unregister_thermal(psy); register_thermal_failed: device_del(dev); device_add_failed: wakeup_init_failed: check_supplies_failed: dev_set_name_failed: put_device(dev); return ERR_PTR(rc); } /** * power_supply_register() - Register new power supply * @parent: Device to be a parent of power supply's device, usually * the device which probe function calls this * @desc: Description of power supply, must be valid through whole * lifetime of this power supply * @cfg: Run-time specific configuration accessed during registering, * may be NULL * * Return: A pointer to newly allocated power_supply on success * or ERR_PTR otherwise. * Use power_supply_unregister() on returned power_supply pointer to release * resources. */ struct power_supply *__must_check power_supply_register(struct device *parent, const struct power_supply_desc *desc, const struct power_supply_config *cfg) { return __power_supply_register(parent, desc, cfg, true); } EXPORT_SYMBOL_GPL(power_supply_register); /** * power_supply_register_no_ws() - Register new non-waking-source power supply * @parent: Device to be a parent of power supply's device, usually * the device which probe function calls this * @desc: Description of power supply, must be valid through whole * lifetime of this power supply * @cfg: Run-time specific configuration accessed during registering, * may be NULL * * Return: A pointer to newly allocated power_supply on success * or ERR_PTR otherwise. * Use power_supply_unregister() on returned power_supply pointer to release * resources. */ struct power_supply *__must_check power_supply_register_no_ws(struct device *parent, const struct power_supply_desc *desc, const struct power_supply_config *cfg) { return __power_supply_register(parent, desc, cfg, false); } EXPORT_SYMBOL_GPL(power_supply_register_no_ws); static void devm_power_supply_release(struct device *dev, void *res) { struct power_supply **psy = res; power_supply_unregister(*psy); } /** * devm_power_supply_register() - Register managed power supply * @parent: Device to be a parent of power supply's device, usually * the device which probe function calls this * @desc: Description of power supply, must be valid through whole * lifetime of this power supply * @cfg: Run-time specific configuration accessed during registering, * may be NULL * * Return: A pointer to newly allocated power_supply on success * or ERR_PTR otherwise. * The returned power_supply pointer will be automatically unregistered * on driver detach. */ struct power_supply *__must_check devm_power_supply_register(struct device *parent, const struct power_supply_desc *desc, const struct power_supply_config *cfg) { struct power_supply **ptr, *psy; ptr = devres_alloc(devm_power_supply_release, sizeof(*ptr), GFP_KERNEL); if (!ptr) return ERR_PTR(-ENOMEM); psy = __power_supply_register(parent, desc, cfg, true); if (IS_ERR(psy)) { devres_free(ptr); } else { *ptr = psy; devres_add(parent, ptr); } return psy; } EXPORT_SYMBOL_GPL(devm_power_supply_register); /** * devm_power_supply_register_no_ws() - Register managed non-waking-source power supply * @parent: Device to be a parent of power supply's device, usually * the device which probe function calls this * @desc: Description of power supply, must be valid through whole * lifetime of this power supply * @cfg: Run-time specific configuration accessed during registering, * may be NULL * * Return: A pointer to newly allocated power_supply on success * or ERR_PTR otherwise. * The returned power_supply pointer will be automatically unregistered * on driver detach. */ struct power_supply *__must_check devm_power_supply_register_no_ws(struct device *parent, const struct power_supply_desc *desc, const struct power_supply_config *cfg) { struct power_supply **ptr, *psy; ptr = devres_alloc(devm_power_supply_release, sizeof(*ptr), GFP_KERNEL); if (!ptr) return ERR_PTR(-ENOMEM); psy = __power_supply_register(parent, desc, cfg, false); if (IS_ERR(psy)) { devres_free(ptr); } else { *ptr = psy; devres_add(parent, ptr); } return psy; } EXPORT_SYMBOL_GPL(devm_power_supply_register_no_ws); /** * power_supply_unregister() - Remove this power supply from system * @psy: Pointer to power supply to unregister * * Remove this power supply from the system. The resources of power supply * will be freed here or on last power_supply_put() call. */ void power_supply_unregister(struct power_supply *psy) { WARN_ON(atomic_dec_return(&psy->use_cnt)); cancel_work_sync(&psy->changed_work); cancel_delayed_work_sync(&psy->deferred_register_work); sysfs_remove_link(&psy->dev.kobj, "powers"); power_supply_remove_triggers(psy); psy_unregister_cooler(psy); psy_unregister_thermal(psy); device_init_wakeup(&psy->dev, false); device_unregister(&psy->dev); } EXPORT_SYMBOL_GPL(power_supply_unregister); void *power_supply_get_drvdata(struct power_supply *psy) { return psy->drv_data; } EXPORT_SYMBOL_GPL(power_supply_get_drvdata); static int __init power_supply_class_init(void) { power_supply_class = class_create(THIS_MODULE, "power_supply"); if (IS_ERR(power_supply_class)) return PTR_ERR(power_supply_class); power_supply_class->dev_uevent = power_supply_uevent; power_supply_init_attrs(&power_supply_dev_type); return 0; } static void __exit power_supply_class_exit(void) { class_destroy(power_supply_class); } subsys_initcall(power_supply_class_init); module_exit(power_supply_class_exit); MODULE_DESCRIPTION("Universal power supply monitor class"); MODULE_AUTHOR("Ian Molton , " "Szabolcs Gyurko, " "Anton Vorontsov "); MODULE_LICENSE("GPL");