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1 /****************************************************************************
2  * include/nuttx/fs/automount.h
3  *
4  * Licensed to the Apache Software Foundation (ASF) under one or more
5  * contributor license agreements.  See the NOTICE file distributed with
6  * this work for additional information regarding copyright ownership.  The
7  * ASF licenses this file to you under the Apache License, Version 2.0 (the
8  * "License"); you may not use this file except in compliance with the
9  * License.  You may obtain a copy of the License at
10  *
11  *   http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing, software
14  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
16  * License for the specific language governing permissions and limitations
17  * under the License.
18  *
19  ****************************************************************************/
20 
21 #ifndef __INCLUDE_NUTTX_AUDIO_AUTOMOUNT_H
22 #define __INCLUDE_NUTTX_AUDIO_AUTOMOUNT_H
23 
24 /****************************************************************************
25  * Included Files
26  ****************************************************************************/
27 
28 #include "stdint.h"
29 
30 
31 #ifdef __cplusplus
32 #if __cplusplus
33 extern "C" {
34 #endif /* __cplusplus */
35 #endif /* __cplusplus */
36 
37 /****************************************************************************
38  * Pre-processor Definitions
39  ****************************************************************************/
40 
41 /* Configuration ************************************************************
42  * Automounter configuration
43  *   CONFIG_FS_AUTOMOUNTER - Enables automount support
44  *
45  * Prerequisites:
46  *   CONFIG_SCHED_WORKQUEUE -  Work queue support is required
47  *   And others that would only matter if you are working in a very minimal
48  *   configuration.
49  */
50 
51 /* Helper macros ************************************************************/
52 
53 #define AUTOMOUNT_ATTACH(s,isr,arg) ((s)->attach(s,isr,arg))
54 #define AUTOMOUNT_DETACH(s)         ((s)->attach(s,NULL,NULL))
55 #define AUTOMOUNT_ENABLE(s)         ((s)->enable(s,true))
56 #define AUTOMOUNT_DISABLE(s)        ((s)->enable(s,false))
57 #define AUTOMOUNT_INSERTED(s)       ((s)->inserted(s))
58 
59 /****************************************************************************
60  * Public Types
61  ****************************************************************************/
62 
63 /* This is the type of the automount media change handler.  The lower level
64  * code will intercept the interrupt and provide the upper level with the
65  * private data that was provided when the interrupt was attached and will
66  * also provide an indication if the media was inserted or removed.
67  */
68 
69 struct automount_lower_s; /* Forward reference.  Defined below */
70 
71 typedef CODE int
72   (*automount_handler_t)(FAR const struct automount_lower_s *lower,
73                          FAR void *arg, bool inserted);
74 
75 /* A reference to a structure of this type must be passed to the FS
76  * automounter.  This structure provides information about the volume to be
77  * mounted and provides board-specific hooks.
78  *
79  * Memory for this structure is provided by the caller.  It is not copied
80  * by the automounter and is presumed to persist while the automounter
81  * is active.
82  */
83 
84 struct automount_lower_s
85 {
86   /* Volume characterization */
87 
88   FAR const char *fstype;     /* Type of file system */
89   FAR const char *blockdev;   /* Path to the block device */
90   FAR const char *mountpoint; /* Location to mount the volume */
91 
92   /* Debounce delay in system clock ticks.  Automount operation will not
93    * be performed until the insertion/removal state has been unchanges
94    * for this duration.
95    */
96 
97   uint32_t ddelay;
98 
99   /* Unmount delay time in system clock ticks.  If a volume has open
100    * references at the time that the media is removed, then we will be
101    * unable to unmount it.  In that case, hopefully, the clients of the
102    * mount will eventually fail with file access errors and eventually close
103    * their references.  So, at some time later, it should be possible to
104    * unmount the volume.  This delay specifies the time between umount
105    * retries.
106    */
107 
108   uint32_t udelay;
109 
110   /* Interrupt related operations all hidden behind callbacks to isolate the
111    * automounter from differences in interrupt handling by varying boards
112    * and MCUs.  Board interrupts should be configured both insertion and
113    * removal of the media can be detected.
114    *
115    * attach  - Attach or detach the media change interrupt handler to the
116    *           board level interrupt
117    * enable  - Enable or disable the media change interrupt
118    */
119 
120   CODE int (*attach)(FAR const struct automount_lower_s *lower,
121                       automount_handler_t isr, FAR void *arg);
122   CODE void (*enable)(FAR const struct automount_lower_s *lower,
123                       bool enable);
124   CODE bool (*inserted)(FAR const struct automount_lower_s *lower);
125 };
126 
127 /****************************************************************************
128  * Public Data
129  ****************************************************************************/
130 
131 #ifdef __cplusplus
132 #define EXTERN extern "C"
133 extern "C"
134 {
135 #else
136 #define EXTERN extern
137 #endif
138 
139 /****************************************************************************
140  * Public Function Prototypes
141  ****************************************************************************/
142 
143 /****************************************************************************
144  * Name: automount_initialize
145  *
146  * Description:
147  *   Configure the automounter.
148  *
149  * Input Parameters:
150  *   lower - Persistent board configuration data
151  *
152  * Returned Value:
153  *   A void* handle.
154  *           The only use for this handle is with automount_uninitialize().
155  *   NULL is returned on any failure.
156  *
157  ****************************************************************************/
158 
159 FAR void *automount_initialize(FAR const struct automount_lower_s *lower);
160 
161 /****************************************************************************
162  * Name: automount_uninitialize
163  *
164  * Description:
165  *   Stop the automounter and free resources that it used.  NOTE that the
166  *   mount is left in its last state mounted/unmounted state.
167  *
168  * Input Parameters:
169  *   handle - The value previously returned by automount_initialize();
170  *
171  * Returned Value:
172  *   None
173  *
174  ****************************************************************************/
175 
176 void automount_uninitialize(FAR void *handle);
177 
178 #undef EXTERN
179 #ifdef __cplusplus
180 }
181 #endif
182 #ifdef __cplusplus
183 #if __cplusplus
184 }
185 #endif /* __cplusplus */
186 #endif /* __cplusplus */
187 
188 #endif /* __INCLUDE_NUTTX_AUDIO_AUTOMOUNT_H */
189