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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 #include <stdbool.h>
30 
31 #include <nuttx/irq.h>
32 
33 #ifdef CONFIG_FS_AUTOMOUNTER
34 
35 /****************************************************************************
36  * Pre-processor Definitions
37  ****************************************************************************/
38 
39 /* Configuration ************************************************************
40  * Automounter configuration
41  *   CONFIG_FS_AUTOMOUNTER - Enables automount support
42  *
43  * Prerequisites:
44  *   CONFIG_SCHED_WORKQUEUE -  Work queue support is required
45  *   And others that would only matter if you are working in a very minimal
46  *   configuration.
47  */
48 
49 /* Helper macros ************************************************************/
50 
51 #define AUTOMOUNT_ATTACH(s,isr,arg) ((s)->attach(s,isr,arg))
52 #define AUTOMOUNT_DETACH(s)         ((s)->attach(s,NULL,NULL))
53 #define AUTOMOUNT_ENABLE(s)         ((s)->enable(s,true))
54 #define AUTOMOUNT_DISABLE(s)        ((s)->enable(s,false))
55 #define AUTOMOUNT_INSERTED(s)       ((s)->inserted(s))
56 
57 /****************************************************************************
58  * Public Types
59  ****************************************************************************/
60 
61 /* This is the type of the automount media change handler.  The lower level
62  * code will intercept the interrupt and provide the upper level with the
63  * private data that was provided when the interrupt was attached and will
64  * also provide an indication if the media was inserted or removed.
65  */
66 
67 struct automount_lower_s; /* Forward reference.  Defined below */
68 
69 typedef CODE int
70   (*automount_handler_t)(FAR const struct automount_lower_s *lower,
71                          FAR void *arg, bool inserted);
72 
73 /* A reference to a structure of this type must be passed to the FS
74  * automounter.  This structure provides information about the volume to be
75  * mounted and provides board-specific hooks.
76  *
77  * Memory for this structure is provided by the caller.  It is not copied
78  * by the automounter and is presumed to persist while the automounter
79  * is active.
80  */
81 
82 struct automount_lower_s
83 {
84   /* Volume characterization */
85 
86   FAR const char *fstype;     /* Type of file system */
87   FAR const char *blockdev;   /* Path to the block device */
88   FAR const char *mountpoint; /* Location to mount the volume */
89 
90   /* Debounce delay in system clock ticks.  Automount operation will not
91    * be performed until the insertion/removal state has been unchanges
92    * for this duration.
93    */
94 
95   uint32_t ddelay;
96 
97   /* Unmount delay time in system clock ticks.  If a volume has open
98    * references at the time that the media is removed, then we will be
99    * unable to unmount it.  In that case, hopefully, the clients of the
100    * mount will eventually fail with file access errors and eventually close
101    * their references.  So, at some time later, it should be possible to
102    * unmount the volume.  This delay specifies the time between umount
103    * retries.
104    */
105 
106   uint32_t udelay;
107 
108   /* Interrupt related operations all hidden behind callbacks to isolate the
109    * automounter from differences in interrupt handling by varying boards
110    * and MCUs.  Board interrupts should be configured both insertion and
111    * removal of the media can be detected.
112    *
113    * attach  - Attach or detach the media change interrupt handler to the
114    *           board level interrupt
115    * enable  - Enable or disable the media change interrupt
116    */
117 
118   CODE int (*attach)(FAR const struct automount_lower_s *lower,
119                       automount_handler_t isr, FAR void *arg);
120   CODE void (*enable)(FAR const struct automount_lower_s *lower,
121                       bool enable);
122   CODE bool (*inserted)(FAR const struct automount_lower_s *lower);
123 };
124 
125 /****************************************************************************
126  * Public Data
127  ****************************************************************************/
128 
129 #ifdef __cplusplus
130 #define EXTERN extern "C"
131 extern "C"
132 {
133 #else
134 #define EXTERN extern
135 #endif
136 
137 /****************************************************************************
138  * Public Function Prototypes
139  ****************************************************************************/
140 
141 /****************************************************************************
142  * Name: automount_initialize
143  *
144  * Description:
145  *   Configure the automounter.
146  *
147  * Input Parameters:
148  *   lower - Persistent board configuration data
149  *
150  * Returned Value:
151  *   A void* handle.
152  *           The only use for this handle is with automount_uninitialize().
153  *   NULL is returned on any failure.
154  *
155  ****************************************************************************/
156 
157 FAR void *automount_initialize(FAR const struct automount_lower_s *lower);
158 
159 /****************************************************************************
160  * Name: automount_uninitialize
161  *
162  * Description:
163  *   Stop the automounter and free resources that it used.  NOTE that the
164  *   mount is left in its last state mounted/unmounted state.
165  *
166  * Input Parameters:
167  *   handle - The value previously returned by automount_initialize();
168  *
169  * Returned Value:
170  *   None
171  *
172  ****************************************************************************/
173 
174 void automount_uninitialize(FAR void *handle);
175 
176 #undef EXTERN
177 #ifdef __cplusplus
178 }
179 #endif
180 
181 #endif /* CONFIG_FS_AUTOMOUNTER */
182 #endif /* __INCLUDE_NUTTX_AUDIO_AUTOMOUNT_H */
183