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BufferedBlockDevice.h
1 /* mbed Microcontroller Library
2  * Copyright (c) 2018 ARM Limited
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a copy
5  * of this software and associated documentation files (the "Software"), to deal
6  * in the Software without restriction, including without limitation the rights
7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8  * copies of the Software, and to permit persons to whom the Software is
9  * furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20  * SOFTWARE.
21  */
22 
23 /** \addtogroup storage */
24 /** @{*/
25 
26 #ifndef MBED_BUFFERED_BLOCK_DEVICE_H
27 #define MBED_BUFFERED_BLOCK_DEVICE_H
28 
29 #include "BlockDevice.h"
30 
31 namespace mbed {
32 
33 /** Block device for allowing minimal read and program sizes (of 1) for the underlying BD,
34  * using a buffer on the heap.
35  */
37 public:
38  /** Lifetime of a memory-buffered block device wrapping an underlying block device
39  *
40  * @param bd Block device to back the BufferedBlockDevice
41  */
43 
44  /** Lifetime of the memory-buffered block device
45  */
46  virtual ~BufferedBlockDevice();
47 
48  /** Initialize a buffered-memory block device and its underlying block device
49  *
50  * @return 0 on success or a negative error code on failure
51  */
52  virtual int init();
53 
54  /** Deinitialize the buffered-memory block device and its underlying block device
55  *
56  * @return 0 on success or a negative error code on failure
57  */
58  virtual int deinit();
59 
60  /** Ensure that data on the underlying storage block device is in sync with the
61  * memory-buffered block device
62  *
63  * @return 0 on success or a negative error code on failure
64  */
65  virtual int sync();
66 
67  /** Read blocks from the memory-buffered block device
68  *
69  * @param buffer Buffer to read blocks into
70  * @param addr Address of block to begin reading from
71  * @param size Size to read in bytes, must be a multiple of read block size
72  * @return 0 on success, negative error code on failure
73  */
74  virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
75 
76  /** Program data to the memory-buffered block device
77  *
78  * The write address blocks must be erased prior to being programmed.
79  *
80  * @param buffer Buffer of data to write to blocks
81  * @param addr Address of block to begin writing to
82  * @param size Size to write in bytes, must be a multiple of program block size
83  * @return 0 on success, negative error code on failure
84  */
85  virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
86 
87  /** Erase blocks from the memory-buffered block device
88  *
89  * The state of an erased block is undefined until it has been programmed,
90  * unless get_erase_value returns a non-negative byte value.
91  *
92  * @param addr Address of block to begin erasing
93  * @param size Size to erase in bytes, must be a multiple of erase block size
94  * @return 0 on success, negative error code on failure
95  */
96  virtual int erase(bd_addr_t addr, bd_size_t size);
97 
98  /** Mark blocks as no longer in use
99  *
100  * This function provides a hint to the underlying block device that a region of blocks
101  * is no longer in use and may be erased without side effects. Erase must still be called
102  * before programming, but trimming allows flash-translation-layers to schedule erases when
103  * the device is not busy.
104  *
105  * @param addr Address of block to mark as unused
106  * @param size Size to mark as unused in bytes, must be a multiple of erase block size
107  * @return 0 on success, negative error code on failure
108  */
109  virtual int trim(bd_addr_t addr, bd_size_t size);
110 
111  /** Get the size of a readable block
112  *
113  * @return Size of a readable block in bytes
114  */
115  virtual bd_size_t get_read_size() const;
116 
117  /** Get the size of a programmable block
118  *
119  * @return Size of a programmable block in bytes
120  * @note Must be a multiple of the read size
121  */
122  virtual bd_size_t get_program_size() const;
123 
124  /** Get the size of an erasable block
125  *
126  * @return Size of an erasable block in bytes
127  * @note Must be a multiple of the program size
128  */
129  virtual bd_size_t get_erase_size() const;
130 
131  /** Get the size of an erasable block of a given address
132  *
133  * @param addr Address within the erasable block
134  * @return Size of an erasable block in bytes
135  * @note Must be a multiple of the program size
136  */
137  virtual bd_size_t get_erase_size(bd_addr_t addr) const;
138 
139  /** Get the value of storage data after being erased
140  *
141  * If get_erase_value returns a non-negative byte value, the underlying
142  * storage is set to that value when erased, and storage containing
143  * that value can be programmed without another erase.
144  *
145  * @return The value of storage when erased, or -1 if you can't
146  * rely on the value of erased storage
147  */
148  virtual int get_erase_value() const;
149 
150  /** Get the total size of the underlying device
151  *
152  * @return Size of the underlying device in bytes
153  */
154  virtual bd_size_t size() const;
155 
156  /** Get the underlying BlockDevice class type
157  *
158  * @return A string representing the underlying BlockDevice class type
159  */
160  virtual const char *get_type() const;
161 
162 protected:
163  BlockDevice *_bd;
164  bd_size_t _bd_program_size;
165  bd_size_t _bd_read_size;
166  bd_size_t _bd_size;
167  bd_size_t _write_cache_addr;
168  bool _write_cache_valid;
169  uint8_t *_write_cache;
170  uint8_t *_read_buf;
171  uint32_t _init_ref_count;
172  bool _is_initialized;
173 
174 #if !(DOXYGEN_ONLY)
175  /** Flush data in cache
176  *
177  * @return 0 on success or a negative error code on failure
178  */
179  int flush();
180 
181  /** Invalidate write cache
182  *
183  * @return none
184  */
185  void invalidate_write_cache();
186 #endif //#if !(DOXYGEN_ONLY)
187 };
188 } // namespace mbed
189 
190 // Added "using" for backwards compatibility
191 #ifndef MBED_NO_GLOBAL_USING_DIRECTIVE
193 #endif
194 
195 #endif
196 
197 /** @}*/
virtual bd_size_t get_program_size() const
Get the size of a programmable block.
virtual int trim(bd_addr_t addr, bd_size_t size)
Mark blocks as no longer in use.
virtual int erase(bd_addr_t addr, bd_size_t size)
Erase blocks from the memory-buffered block device.
virtual bd_size_t get_erase_size() const
Get the size of an erasable block.
BufferedBlockDevice(BlockDevice *bd)
Lifetime of a memory-buffered block device wrapping an underlying block device.
A hardware device capable of writing and reading blocks.
Definition: BlockDevice.h:47
virtual int sync()
Ensure that data on the underlying storage block device is in sync with the memory-buffered block dev...
virtual int get_erase_value() const
Get the value of storage data after being erased.
virtual int deinit()
Deinitialize the buffered-memory block device and its underlying block device.
virtual int init()
Initialize a buffered-memory block device and its underlying block device.
Block device for allowing minimal read and program sizes (of 1) for the underlying BD...
virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size)
Program data to the memory-buffered block device.
virtual bd_size_t get_read_size() const
Get the size of a readable block.
virtual bd_size_t size() const
Get the total size of the underlying device.
Definition: AnalogIn.h:28
virtual int read(void *buffer, bd_addr_t addr, bd_size_t size)
Read blocks from the memory-buffered block device.
virtual const char * get_type() const
Get the underlying BlockDevice class type.
virtual ~BufferedBlockDevice()
Lifetime of the memory-buffered block device.
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