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29 * Copyright 2009 Develer S.r.l. (http://www.develer.com/)
33 * \author Francesco Sacchi <batt@develer.com>
35 * \brief KBlock interface
41 #include <cfg/compiler.h>
42 #include <cfg/debug.h>
43 #include <cfg/macros.h>
45 /** Type for addressing blocks in the device. */
46 typedef uint32_t block_idx_t;
52 * \name Prototypes for KBlock access functions.
54 * A KBlock user can choose which function subset to implement,
55 * but has to set to NULL unimplemented features.
59 typedef size_t (* kblock_read_direct_t) (struct KBlock *b, block_idx_t index, void *buf, size_t offset, size_t size);
60 typedef size_t (* kblock_read_t) (struct KBlock *b, void *buf, size_t offset, size_t size);
61 typedef size_t (* kblock_write_t) (struct KBlock *b, const void *buf, size_t offset, size_t size);
62 typedef int (* kblock_load_t) (struct KBlock *b, block_idx_t index);
63 typedef int (* kblock_store_t) (struct KBlock *b, block_idx_t index);
64 typedef int (* kblock_error_t) (struct KBlock *b);
65 typedef int (* kblock_clearerr_t) (struct KBlock *b);
66 typedef int (* kblock_close_t) (struct KBlock *b);
70 * Table of interface functions for a KBlock device.
72 typedef struct KBlockVTable
74 kblock_read_direct_t readDirect;
75 kblock_read_t readBuf;
76 kblock_write_t writeBuf;
80 kblock_error_t error; ///< \sa kblock_error()
81 kblock_clearerr_t clearerr; ///< \sa kblock_clearerr()
83 kblock_close_t close; ///< \sa kblock_close()
88 * KBlock private members.
89 * These are the private members of the KBlock class, please do not
90 * access these directly, use the KBlock API.
92 typedef struct KBlockPriv
94 DB(id_t type); ///< Used to keep track, at runtime, of the class type.
95 int flags; ///< Status and error flags.
96 block_idx_t blk_start; ///< Start block number when the device is trimmed. \sa kblock_trim()
100 struct KBlockVTable *vt; ///< Virtual table of interface functions.
104 * KBlock: interface for a generic block device.
106 * A block device is a device which can only be read/written
107 * with data blocks of constant size: flash memories,
108 * SD cards, hard disks, etc...
110 * This interface is designed to adapt to most block devices and
111 * use peculiar features in order to save CPU time and memory space.
113 * You do not have to use this structure directly, specific implementations
114 * will be supplied in the peripheral drivers.
116 typedef struct KBlock
118 KBlockPriv priv; ///< Interface private data, do not use directly.
120 /* Public access members/methods */
121 size_t blk_size; ///< Block size.
122 block_idx_t blk_cnt; ///< Number of blocks available in the device.
127 * Use a subset of the blocks on the device.
129 * This function is useful for partitioning a device and use it for
130 * different purposes at the same time.
132 * This function will limit the number of blocks used on the device by setting
133 * a start index and a number of blocks to be used counting from that index.
135 * The blocks outside this range are no more accessible.
137 * Logical block indexes will be mapped to physical indexes inside this new
138 * range automatically. Even following calls to kblock_trim() will use logical
139 * indexes, so, once trimmed, access can only be limited further and never
144 * //...init KBlock device dev
145 * kblock_trim(dev, 200, 1500); // Restrict access to the 200-1700 physical block range.
146 * kblock_load(dev, 0); // Load the physical block #200.
147 * kblock_trim(dev, 0, 300); // Restrict access to the 200-500 physical block range.
150 * \param b KBlock device.
151 * \param start The index of the start block for the limiting window in logical addressing units.
152 * \param count The number of blocks to be used.
155 INLINE void kblock_trim(struct KBlock *b, block_idx_t start, block_idx_t count)
157 ASSERT(start + count <= b->blk_cnt);
158 b->priv.blk_start += start;
163 #define KB_ASSERT_METHOD(b, method) \
167 ASSERT((b)->priv.vt); \
168 ASSERT((b)->priv.vt->method); \
174 * Get the current errors for the device.
176 * \note Calling this function will not clear the errors.
178 * \param b KBlock device.
180 * \return 0 if no error is present, a driver specific mask of errors otherwise.
182 * \sa kblock_clearerr()
184 INLINE int kblock_error(struct KBlock *b)
186 KB_ASSERT_METHOD(b, error);
187 return b->priv.vt->error(b);
191 * Clear the errors of the device.
193 * \param b KBlock device.
195 * \return 0 on success, EOF on errors.
199 INLINE int kblock_clearerr(struct KBlock *b)
201 KB_ASSERT_METHOD(b, clearerr);
202 return b->priv.vt->clearerr(b);
208 * \param b KBlock device.
210 * \return 0 on success, EOF on errors.
212 INLINE int kblock_close(struct KBlock *b)
214 KB_ASSERT_METHOD(b, close);
215 return b->priv.vt->close(b);
218 size_t kblock_read(struct KBlock *b, block_idx_t idx, void *buf, size_t offset, size_t size);
220 int kblock_flush(struct KBlock *b);
222 size_t kblock_write(struct KBlock *b, block_idx_t idx, const void *buf, size_t offset, size_t size);
224 int kblock_copy(struct KBlock *b, block_idx_t idx1, block_idx_t idx2);
226 #endif /* IO_KBLOCK_H */