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/*
* 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);
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