From 046050f6e623e442e9c71c525462ebd395dae526 Mon Sep 17 00:00:00 2001 From: Chanwoo Choi Date: Tue, 19 May 2015 20:01:12 +0900 Subject: extcon: Update the prototype of extcon_register_notifier() with enum extcon Previously, extcon consumer driver used the extcon_register_interest() to register the notifier chain and then to receive the notifier event when external connector's state is changed. When registering the notifier chain for specific external connector with extcon_register_interest(), it used the the string name of external connector directly. There are potential problem because of unclear, non-standard and inconsequent cable name. Namely, it is not appropriate method to identify each external connector. So, this patch modify the prototype of extcon_register_notifier() by using the 'enum extcon' which are the unique id for each external connector instead of unclear string method. - Previously, the extcon consumer driver used the extcon_register_interest() with 'cable_name' to point out the specific external connector. Also. it used the un-needed structure (struct extcon_specific_cable_nb). : int extcon_register_interest(struct extcon_specific_cable_nb *obj, const char *extcon_name, const char *cable_name, struct notifier_block *nb) - Newly, the updated extcon_register_notifier() would definitely support the same feature to detech the changed state of external connector without any specific structure (struct extcon_specific_cable_nb). : int extcon_register_notifier(struct extcon_dev *edev, enum extcon id, struct notifier_block *nb) This patch support the both extcon_register_interest() and new extcon_register_ notifier(). But the extcon_{register|unregister}_interest() will be deprecated because extcon core would support the notifier event for extcon consumer driver with only updated extcon_register_notifier() and 'extcon_specific_cable_nb' will be removed if there are no extcon consumer driver with legacy extcon_{register|unregister}_interest(). Signed-off-by: Chanwoo Choi Reviewed-by: Krzysztof Kozlowski --- drivers/extcon/extcon.c | 91 ++++++++++++++++++++++++++----------------------- include/linux/extcon.h | 17 +++++---- 2 files changed, 56 insertions(+), 52 deletions(-) diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c index fce2687bde8e..5099c11d8833 100644 --- a/drivers/extcon/extcon.c +++ b/drivers/extcon/extcon.c @@ -146,6 +146,16 @@ static int find_cable_index_by_name(struct extcon_dev *edev, const char *name) return find_cable_index_by_id(edev, id); } +static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached) +{ + if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) { + *attached = new ? true : false; + return true; + } + + return false; +} + static ssize_t state_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -254,23 +264,27 @@ int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state) char *envp[3]; int env_offset = 0; int length; + int index; unsigned long flags; + bool attached; spin_lock_irqsave(&edev->lock, flags); if (edev->state != ((edev->state & ~mask) | (state & mask))) { - u32 old_state = edev->state; - if (check_mutually_exclusive(edev, (edev->state & ~mask) | (state & mask))) { spin_unlock_irqrestore(&edev->lock, flags); return -EPERM; } + for (index = 0; index < edev->max_supported; index++) { + if (is_extcon_changed(edev->state, state, index, &attached)) + raw_notifier_call_chain(&edev->nh[index], attached, edev); + } + edev->state &= ~mask; edev->state |= state & mask; - raw_notifier_call_chain(&edev->nh, old_state, edev); /* This could be in interrupt handler */ prop_buf = (char *)get_zeroed_page(GFP_ATOMIC); if (prop_buf) { @@ -423,29 +437,6 @@ out: } EXPORT_SYMBOL_GPL(extcon_get_extcon_dev); -static int _call_per_cable(struct notifier_block *nb, unsigned long val, - void *ptr) -{ - struct extcon_specific_cable_nb *obj = container_of(nb, - struct extcon_specific_cable_nb, internal_nb); - struct extcon_dev *edev = ptr; - - if ((val & (1 << obj->cable_index)) != - (edev->state & (1 << obj->cable_index))) { - bool cable_state = true; - - obj->previous_value = val; - - if (val & (1 << obj->cable_index)) - cable_state = false; - - return obj->user_nb->notifier_call(obj->user_nb, - cable_state, ptr); - } - - return NOTIFY_OK; -} - /** * extcon_register_interest() - Register a notifier for a state change of a * specific cable, not an entier set of cables of a @@ -491,11 +482,10 @@ int extcon_register_interest(struct extcon_specific_cable_nb *obj, obj->user_nb = nb; - obj->internal_nb.notifier_call = _call_per_cable; - spin_lock_irqsave(&obj->edev->lock, flags); - ret = raw_notifier_chain_register(&obj->edev->nh, - &obj->internal_nb); + ret = raw_notifier_chain_register( + &obj->edev->nh[obj->cable_index], + obj->user_nb); spin_unlock_irqrestore(&obj->edev->lock, flags); } else { struct class_dev_iter iter; @@ -538,7 +528,8 @@ int extcon_unregister_interest(struct extcon_specific_cable_nb *obj) return -EINVAL; spin_lock_irqsave(&obj->edev->lock, flags); - ret = raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb); + ret = raw_notifier_chain_unregister( + &obj->edev->nh[obj->cable_index], obj->user_nb); spin_unlock_irqrestore(&obj->edev->lock, flags); return ret; @@ -548,21 +539,24 @@ EXPORT_SYMBOL_GPL(extcon_unregister_interest); /** * extcon_register_notifier() - Register a notifiee to get notified by * any attach status changes from the extcon. - * @edev: the extcon device. + * @edev: the extcon device that has the external connecotr. + * @id: the unique id of each external connector in extcon enumeration. * @nb: a notifier block to be registered. * * Note that the second parameter given to the callback of nb (val) is * "old_state", not the current state. The current state can be retrieved * by looking at the third pameter (edev pointer)'s state value. */ -int extcon_register_notifier(struct extcon_dev *edev, - struct notifier_block *nb) +int extcon_register_notifier(struct extcon_dev *edev, enum extcon id, + struct notifier_block *nb) { unsigned long flags; - int ret; + int ret, idx; + + idx = find_cable_index_by_id(edev, id); spin_lock_irqsave(&edev->lock, flags); - ret = raw_notifier_chain_register(&edev->nh, nb); + ret = raw_notifier_chain_register(&edev->nh[idx], nb); spin_unlock_irqrestore(&edev->lock, flags); return ret; @@ -571,17 +565,20 @@ EXPORT_SYMBOL_GPL(extcon_register_notifier); /** * extcon_unregister_notifier() - Unregister a notifiee from the extcon device. - * @edev: the extcon device. - * @nb: a registered notifier block to be unregistered. + * @edev: the extcon device that has the external connecotr. + * @id: the unique id of each external connector in extcon enumeration. + * @nb: a notifier block to be registered. */ -int extcon_unregister_notifier(struct extcon_dev *edev, - struct notifier_block *nb) +int extcon_unregister_notifier(struct extcon_dev *edev, enum extcon id, + struct notifier_block *nb) { unsigned long flags; - int ret; + int ret, idx; + + idx = find_cable_index_by_id(edev, id); spin_lock_irqsave(&edev->lock, flags); - ret = raw_notifier_chain_unregister(&edev->nh, nb); + ret = raw_notifier_chain_unregister(&edev->nh[idx], nb); spin_unlock_irqrestore(&edev->lock, flags); return ret; @@ -893,7 +890,15 @@ int extcon_dev_register(struct extcon_dev *edev) spin_lock_init(&edev->lock); - RAW_INIT_NOTIFIER_HEAD(&edev->nh); + edev->nh = devm_kzalloc(&edev->dev, + sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL); + if (!edev->nh) { + ret = -ENOMEM; + goto err_dev; + } + + for (index = 0; index < edev->max_supported; index++) + RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]); dev_set_drvdata(&edev->dev, edev); edev->state = 0; diff --git a/include/linux/extcon.h b/include/linux/extcon.h index 85c882f0029e..be9652b3a154 100644 --- a/include/linux/extcon.h +++ b/include/linux/extcon.h @@ -116,7 +116,7 @@ struct extcon_dev { /* Internal data. Please do not set. */ struct device dev; - struct raw_notifier_head nh; + struct raw_notifier_head *nh; struct list_head entry; int max_supported; spinlock_t lock; /* could be called by irq handler */ @@ -155,8 +155,6 @@ struct extcon_cable { /** * struct extcon_specific_cable_nb - An internal data for * extcon_register_interest(). - * @internal_nb: A notifier block bridging extcon notifier - * and cable notifier. * @user_nb: user provided notifier block for events from * a specific cable. * @cable_index: the target cable. @@ -164,7 +162,6 @@ struct extcon_cable { * @previous_value: the saved previous event value. */ struct extcon_specific_cable_nb { - struct notifier_block internal_nb; struct notifier_block *user_nb; int cable_index; struct extcon_dev *edev; @@ -240,10 +237,10 @@ extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb); * we do not recommend to use this for normal 'notifiee' device drivers who * want to be notified by a specific external port of the notifier. */ -extern int extcon_register_notifier(struct extcon_dev *edev, +extern int extcon_register_notifier(struct extcon_dev *edev, enum extcon id, + struct notifier_block *nb); +extern int extcon_unregister_notifier(struct extcon_dev *edev, enum extcon id, struct notifier_block *nb); -extern int extcon_unregister_notifier(struct extcon_dev *edev, - struct notifier_block *nb); /* * Following API get the extcon device from devicetree. @@ -333,13 +330,15 @@ static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name) } static inline int extcon_register_notifier(struct extcon_dev *edev, - struct notifier_block *nb) + enum extcon id, + struct notifier_block *nb) { return 0; } static inline int extcon_unregister_notifier(struct extcon_dev *edev, - struct notifier_block *nb) + enum extcon id, + struct notifier_block *nb) { return 0; } -- cgit v1.2.3-59-g8ed1b