diff options
Diffstat (limited to 'drivers/mxc/pmic/core/pmic_event.c')
| -rw-r--r-- | drivers/mxc/pmic/core/pmic_event.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/mxc/pmic/core/pmic_event.c b/drivers/mxc/pmic/core/pmic_event.c new file mode 100644 index 000000000000..c8ffc63a4973 --- /dev/null +++ b/drivers/mxc/pmic/core/pmic_event.c @@ -0,0 +1,236 @@ +/* + * Copyright 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +/*! + * @file pmic_event.c + * @brief This file manage all event of PMIC component. + * + * It contains event subscription, unsubscription and callback + * launch methods implemeted. + * + * @ingroup PMIC_CORE + */ + +/* + * Includes + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/pmic_external.h> +#include <linux/pmic_status.h> +#include "pmic.h" + +/*! + * This structure is used to keep a list of subscribed + * callbacks for an event. + */ +typedef struct { + /*! + * Keeps a list of subscribed clients to an event. + */ + struct list_head list; + + /*! + * Callback function with parameter, called when event occurs + */ + pmic_event_callback_t callback; +} pmic_event_callback_list_t; + +/* Create a mutex to be used to prevent concurrent access to the event list */ +static DEFINE_MUTEX(event_mutex); + +/* This is a pointer to the event handler array. It defines the currently + * active set of events and user-defined callback functions. + */ +static struct list_head pmic_events[PMIC_MAX_EVENTS]; + +/*! + * This function initializes event list for PMIC event handling. + * + */ +void pmic_event_list_init(void) +{ + int i; + + for (i = 0; i < PMIC_MAX_EVENTS; i++) { + INIT_LIST_HEAD(&pmic_events[i]); + } + + mutex_init(&event_mutex); + return; +} + +/*! + * This function is used to subscribe on an event. + * + * @param event the event number to be subscribed + * @param callback the callback funtion to be subscribed + * + * @return This function returns 0 on SUCCESS, error on FAILURE. + */ +PMIC_STATUS pmic_event_subscribe(type_event event, + pmic_event_callback_t callback) +{ + pmic_event_callback_list_t *new = NULL; + + pr_debug("Event:%d Subscribe\n", event); + + /* Check whether the event & callback are valid? */ + if (event >= PMIC_MAX_EVENTS) { + pr_debug("Invalid Event:%d\n", event); + return -EINVAL; + } + if (NULL == callback.func) { + pr_debug("Null or Invalid Callback\n"); + return -EINVAL; + } + + /* Create a new linked list entry */ + new = kmalloc(sizeof(pmic_event_callback_list_t), GFP_KERNEL); + if (NULL == new) { + return -ENOMEM; + } + /* Initialize the list node fields */ + new->callback.func = callback.func; + new->callback.param = callback.param; + INIT_LIST_HEAD(&new->list); + + /* Obtain the lock to access the list */ + if (mutex_lock_interruptible(&event_mutex)) { + kfree(new); + return PMIC_SYSTEM_ERROR_EINTR; + } + + /* Unmask the requested event */ + if (list_empty(&pmic_events[event])) { + if (pmic_event_unmask(event) != PMIC_SUCCESS) { + kfree(new); + mutex_unlock(&event_mutex); + return PMIC_ERROR; + } + } + + /* Add this entry to the event list */ + list_add_tail(&new->list, &pmic_events[event]); + + /* Release the lock */ + mutex_unlock(&event_mutex); + + return PMIC_SUCCESS; +} + +/*! + * This function is used to unsubscribe on an event. + * + * @param event the event number to be unsubscribed + * @param callback the callback funtion to be unsubscribed + * + * @return This function returns 0 on SUCCESS, error on FAILURE. + */ +PMIC_STATUS pmic_event_unsubscribe(type_event event, + pmic_event_callback_t callback) +{ + struct list_head *p; + struct list_head *n; + pmic_event_callback_list_t *temp = NULL; + int ret = PMIC_EVENT_NOT_SUBSCRIBED; + + pr_debug("Event:%d Unsubscribe\n", event); + + /* Check whether the event & callback are valid? */ + if (event >= PMIC_MAX_EVENTS) { + pr_debug("Invalid Event:%d\n", event); + return -EINVAL; + } + + if (NULL == callback.func) { + pr_debug("Null or Invalid Callback\n"); + return -EINVAL; + } + + /* Obtain the lock to access the list */ + if (mutex_lock_interruptible(&event_mutex)) { + return PMIC_SYSTEM_ERROR_EINTR; + } + + /* Find the entry in the list */ + list_for_each_safe(p, n, &pmic_events[event]) { + temp = list_entry(p, pmic_event_callback_list_t, list); + if (temp->callback.func == callback.func + && temp->callback.param == callback.param) { + /* Remove the entry from the list */ + list_del(p); + kfree(temp); + ret = PMIC_SUCCESS; + break; + } + } + + /* Unmask the requested event */ + if (list_empty(&pmic_events[event])) { + if (pmic_event_mask(event) != PMIC_SUCCESS) { + ret = PMIC_UNSUBSCRIBE_ERROR; + } + } + + /* Release the lock */ + mutex_unlock(&event_mutex); + + return ret; +} + +/*! + * This function calls all callback of a specific event. + * + * @param event the active event number + * + * @return None + */ +void pmic_event_callback(type_event event) +{ + struct list_head *p; + pmic_event_callback_list_t *temp = NULL; + + /* Obtain the lock to access the list */ + if (mutex_lock_interruptible(&event_mutex)) { + return; + } + + if (list_empty(&pmic_events[event])) { + pr_debug("PMIC Event:%d detected. No callback subscribed\n", + event); + mutex_unlock(&event_mutex); + return; + } + + list_for_each(p, &pmic_events[event]) { + temp = list_entry(p, pmic_event_callback_list_t, list); + temp->callback.func(temp->callback.param); + } + + /* Release the lock */ + mutex_unlock(&event_mutex); + + return; + +} + +EXPORT_SYMBOL(pmic_event_subscribe); +EXPORT_SYMBOL(pmic_event_unsubscribe); |