release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/staging/tidspbridge/include/dspbridge/ntfy.h

   1 /*
   2  * ntfy.h
   3  *
   4  * DSP-BIOS Bridge driver support functions for TI OMAP processors.
   5  *
   6  * Manage lists of notification events.
   7  *
   8  * Copyright (C) 2005-2006 Texas Instruments, Inc.
   9  *
  10  * This package is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  16  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  17  */
  18
  19 #ifndef NTFY_
  20 #define NTFY_
  21
  22 #include <dspbridge/host_os.h>
  23 #include <dspbridge/dbdefs.h>
  24 #include <dspbridge/sync.h>
  25
  26 /**
  27  * ntfy_object - head structure to nofify dspbridge events
  28  * @head:       List of notify objects
  29  * @ntfy_lock:  lock for list access.
  30  *
  31  */
  32 struct ntfy_object {
  33         struct raw_notifier_head head;/* List of notifier objects */
  34         spinlock_t ntfy_lock;   /* For critical sections */
  35 };
  36
  37 /**
  38  * ntfy_event - structure store specify event to be notified
  39  * @noti_block: List of notify objects
  40  * @event:      event that it respond
  41  * @type:       event type (only DSP_SIGNALEVENT supported)
  42  * @sync_obj:   sync_event used to set the event
  43  *
  44  */
  45 struct ntfy_event {
  46         struct notifier_block noti_block;
  47         u32 event;      /* Events to be notified about */
  48         u32 type;       /* Type of notification to be sent */
  49         struct sync_object sync_obj;
  50 };
  51
  52
  53 /**
  54  * dsp_notifier_event() - callback function to nofity events
  55  * @this:               pointer to itself struct notifier_block
  56  * @event:      event to be notified.
  57  * @data:               Currently not used.
  58  *
  59  */
  60 int dsp_notifier_event(struct notifier_block *this, unsigned long event,
  61                            void *data);
  62
  63 /**
  64  * ntfy_init() - Set the initial state of the ntfy_object structure.
  65  * @no:         pointer to ntfy_object structure.
  66  *
  67  * This function sets the initial state of the ntfy_object in order it
  68  * can be used by the other ntfy functions.
  69  */
  70
  71 static inline void ntfy_init(struct ntfy_object *no)
  72 {
  73         spin_lock_init(&no->ntfy_lock);
  74         RAW_INIT_NOTIFIER_HEAD(&no->head);
  75 }
  76
  77 /**
  78  * ntfy_delete() - delete list of nofy events registered.
  79  * @ntfy_obj:   Pointer to the ntfy object structure.
  80  *
  81  * This function is used to remove all the notify events  registered.
  82  * unregister function is not needed in this function, to unregister
  83  * a ntfy_event please look at ntfy_register function.
  84  *
  85  */
  86 static inline void ntfy_delete(struct ntfy_object *ntfy_obj)
  87 {
  88         struct ntfy_event *ne;
  89         struct notifier_block *nb;
  90
  91         spin_lock_bh(&ntfy_obj->ntfy_lock);
  92         nb = ntfy_obj->head.head;
  93         while (nb) {
  94                 ne = container_of(nb, struct ntfy_event, noti_block);
  95                 nb = nb->next;
  96                 kfree(ne);
  97         }
  98         spin_unlock_bh(&ntfy_obj->ntfy_lock);
  99 }
 100
 101 /**
 102  * ntfy_notify() - nofity all event register for an specific event.
 103  * @ntfy_obj:   Pointer to the ntfy_object structure.
 104  * @event:      event to be notified.
 105  *
 106  * This function traverses all the ntfy events registers and
 107  * set the event with mach with @event.
 108  */
 109 static inline void ntfy_notify(struct ntfy_object *ntfy_obj, u32 event)
 110 {
 111         spin_lock_bh(&ntfy_obj->ntfy_lock);
 112         raw_notifier_call_chain(&ntfy_obj->head, event, NULL);
 113         spin_unlock_bh(&ntfy_obj->ntfy_lock);
 114 }
 115
 116
 117
 118 /**
 119  * ntfy_init() - Create and initialize a ntfy_event structure.
 120  * @event:      event that the ntfy event will respond
 121  * @type                event type (only DSP_SIGNALEVENT supported)
 122  *
 123  * This function create a ntfy_event element and sets the event it will
 124  * respond the ntfy_event in order it can be used by the other ntfy functions.
 125  * In case of success it will return a pointer to the ntfy_event struct
 126  * created. Otherwise it will return NULL;
 127  */
 128
 129 static inline struct ntfy_event *ntfy_event_create(u32 event, u32 type)
 130 {
 131         struct ntfy_event *ne;
 132         ne = kmalloc(sizeof(struct ntfy_event), GFP_KERNEL);
 133         if (ne) {
 134                 sync_init_event(&ne->sync_obj);
 135                 ne->noti_block.notifier_call = dsp_notifier_event;
 136                 ne->event = event;
 137                 ne->type = type;
 138         }
 139         return ne;
 140 }
 141
 142 /**
 143  * ntfy_register() - register new ntfy_event into a given ntfy_object
 144  * @ntfy_obj:   Pointer to the ntfy_object structure.
 145  * @noti:               Pointer to the handle to be returned to the user space.
 146  * @event       event that the ntfy event will respond
 147  * @type                event type (only DSP_SIGNALEVENT supported)
 148  *
 149  * This function register a new ntfy_event into the ntfy_object list,
 150  * which will respond to the @event passed.
 151  * This function will return 0 in case of error.
 152  * -EFAULT in case of bad pointers and
 153  * DSP_EMemory in case of no memory to create ntfy_event.
 154  */
 155 static  inline int ntfy_register(struct ntfy_object *ntfy_obj,
 156                          struct dsp_notification *noti,
 157                          u32 event, u32 type)
 158 {
 159         struct ntfy_event *ne;
 160         int status = 0;
 161
 162         if (!noti || !ntfy_obj) {
 163                 status = -EFAULT;
 164                 goto func_end;
 165         }
 166         if (!event) {
 167                 status = -EINVAL;
 168                 goto func_end;
 169         }
 170         ne = ntfy_event_create(event, type);
 171         if (!ne) {
 172                 status = -ENOMEM;
 173                 goto func_end;
 174         }
 175         noti->handle = &ne->sync_obj;
 176
 177         spin_lock_bh(&ntfy_obj->ntfy_lock);
 178         raw_notifier_chain_register(&ntfy_obj->head, &ne->noti_block);
 179         spin_unlock_bh(&ntfy_obj->ntfy_lock);
 180 func_end:
 181         return status;
 182 }
 183
 184 /**
 185  * ntfy_unregister() - unregister a ntfy_event from a given ntfy_object
 186  * @ntfy_obj:   Pointer to the ntfy_object structure.
 187  * @noti:               Pointer to the event that will be removed.
 188  *
 189  * This function unregister a ntfy_event from the ntfy_object list,
 190  * @noti contains the event which is wanted to be removed.
 191  * This function will return 0 in case of error.
 192  * -EFAULT in case of bad pointers and
 193  * DSP_EMemory in case of no memory to create ntfy_event.
 194  */
 195 static  inline int ntfy_unregister(struct ntfy_object *ntfy_obj,
 196                          struct dsp_notification *noti)
 197 {
 198         int status = 0;
 199         struct ntfy_event *ne;
 200
 201         if (!noti || !ntfy_obj) {
 202                 status = -EFAULT;
 203                 goto func_end;
 204         }
 205
 206         ne = container_of((struct sync_object *)noti, struct ntfy_event,
 207                                                                 sync_obj);
 208         spin_lock_bh(&ntfy_obj->ntfy_lock);
 209         raw_notifier_chain_unregister(&ntfy_obj->head,
 210                                                 &ne->noti_block);
 211         kfree(ne);
 212         spin_unlock_bh(&ntfy_obj->ntfy_lock);
 213 func_end:
 214         return status;
 215 }
 216
 217 #endif                          /* NTFY_ */