From 9ca0ab9c40325c9d6f74ac31c5bb992429a7bc69 Mon Sep 17 00:00:00 2001 From: batt Date: Fri, 9 Jul 2010 16:39:21 +0000 Subject: [PATCH] Add some documentation. git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4020 38d2e660-2303-0410-9eaa-f027e97ec537 --- bertos/io/kblock.h | 134 +++++++++++++++++++++++++++++++++++++++------ 1 file changed, 116 insertions(+), 18 deletions(-) diff --git a/bertos/io/kblock.h b/bertos/io/kblock.h index c0d23e03..99135ab2 100644 --- a/bertos/io/kblock.h +++ b/bertos/io/kblock.h @@ -49,10 +49,11 @@ typedef uint32_t block_idx_t; struct KBlock; /** - * \name Prototypes for KBlock access functions. + * \name Prototypes for KBlock low level access functions. * - * A KBlock user can choose which function subset to implement, - * but has to set to NULL unimplemented features. + * When writing a driver implementing the KBlock interface you can choose which + * function subset to implement, but you have to set to NULL unimplemented + * features. * * \{ */ @@ -76,12 +77,12 @@ typedef struct KBlockVTable { kblock_read_direct_t readDirect; kblock_write_block_t writeBlock; - + kblock_read_t readBuf; kblock_write_t writeBuf; kblock_load_t load; kblock_store_t store; - + kblock_error_t error; ///< \sa kblock_error() kblock_clearerr_t clearerr; ///< \sa kblock_clearerr() @@ -89,21 +90,21 @@ typedef struct KBlockVTable } KBlockVTable; -#define KB_BUFFERED BV(0) -#define KB_CACHE_DIRTY BV(1) +#define KB_BUFFERED BV(0) ///< Internal flag: true if the KBlock has a buffer +#define KB_CACHE_DIRTY BV(1) ///< Internal flag: true if the cache is dirty /** * KBlock private members. - * These are the private members of the KBlock class, please do not + * These are the private members of the KBlock interface, please do not * access these directly, use the KBlock API. */ typedef struct KBlockPriv { DB(id_t type); ///< Used to keep track, at runtime, of the class type. int flags; ///< Status and error flags. - void *buf; - block_idx_t blk_start; ///< Start block number when the device is trimmed. \sa kblock_trim() - block_idx_t curr_blk; + void *buf; ///< Pointer to the page buffer for RAM-cached KBlocks. + block_idx_t blk_start; ///< Start block number when the device is trimmed. \sa kblock_trim(). + block_idx_t curr_blk; ///< Current cached block number in cached KBlocks. const struct KBlockVTable *vt; ///< Virtual table of interface functions. } KBlockPriv; @@ -151,7 +152,7 @@ typedef struct KBlock * \code * //...init KBlock device dev * kblock_trim(dev, 200, 1500); // Restrict access to the 200-1700 physical block range. - * kblock_load(dev, 0); // Load the physical block #200. + * kblock_read(dev, 0, buf, 0, dev->blk_size); // Read from physical block #200. * kblock_trim(dev, 0, 300); // Restrict access to the 200-500 physical block range. * \endcode * @@ -223,30 +224,127 @@ INLINE int kblock_close(struct KBlock *b) return b->priv.vt->close(b); } -INLINE bool kblock_cacheDirty(struct KBlock *b) +/** + * \return true if the device \a b is buffered, false otherwise. + * \param b KBlock device. + * \sa kblock_cachedBlock(), kblock_cacheDirty(). + */ +INLINE bool kblock_buffered(struct KBlock *b) { ASSERT(b); - return (b->priv.flags & KB_CACHE_DIRTY); + return (b->priv.flags & KB_BUFFERED); } + +/** + * \return The current cached block number if the device is buffered. + * \param b KBlock device. + * \note This function will throw an ASSERT if called on a non buffered KBlock. + * \sa kblock_buffered(), kblock_cacheDirty(). + */ INLINE block_idx_t kblock_cachedBlock(struct KBlock *b) { + ASSERT(kblock_buffered(b)); return b->priv.curr_blk; } -INLINE bool kblock_buffered(struct KBlock *b) + +/** + * Return the status of the internal cache. + * + * \param b KBlock device. + * \return If the device supports buffering, returns true if the cache is dirty, + * false if the cache is clean and coherent with device content. + * \note This function will throw an ASSERT if called on a non buffered KBlock. + * \sa kblock_cachedBlock(), kblock_buffered(). + */ +INLINE bool kblock_cacheDirty(struct KBlock *b) { - ASSERT(b); - return (b->priv.flags & KB_BUFFERED); + ASSERT(kblock_buffered(b)); + return kblock_buffered(b) && (b->priv.flags & KB_CACHE_DIRTY); } + +/** + * Read data from the block device. + * + * This function will read \a size bytes from block \a idx starting at + * address \a offset inside the block. + * + * Most block devices (almost all flash memories, for instance), + * can efficiently read even a part of the block. + * + * \note This function can be slow if you try to partial read a block from + * a device which does not support partial block reads and is opened + * in unbuffered mode. + * + * \param b KBlock device. + * \param idx the block number where you want to read. + * \param buf a buffer where the data will be read. + * \param offset the offset inside the block from which data reading will start. + * \param size the size of data to be read. + * + * \return the number of bytes read. + * + * \sa kblock_write(). + */ size_t kblock_read(struct KBlock *b, block_idx_t idx, void *buf, size_t offset, size_t size); + +/** + * Write data to the block device. + * + * This function will write \a size bytes to block \a idx starting at + * address \a offset inside the block. + * + * \note Partial block writes are supported only if the device is opened in + * buffered mode. You can use kblock_buffered() to check if the device + * has an internal cache or not. + * + * \note If the device is opened in buffered mode, this function will use + * efficiently and trasparently the cache provided. + * In order to be sure that all modifications are actually written + * to the device you have to call kblock_flush(). + * + * \param b KBlock device. + * \param idx the block number where you want to write. + * \param buf a pointer to the data to be written. + * \param offset the offset inside the block from which data writing will start. + * \param size the size of data to be written. + * + * \return the number of bytes written. + * + * \sa kblock_read(), kblock_flush(), kblock_buffered(). + */ size_t kblock_write(struct KBlock *b, block_idx_t idx, const void *buf, size_t offset, size_t size); + +/** + * Flush the cache (if any) to the device. + * + * This function will write any pending modifications to the device. + * If the device does not have a cache, this function will do nothing. + * + * \return 0 if all is OK, EOF on errors. + * \sa kblock_read(), kblock_write(), kblock_buffered(). + */ int kblock_flush(struct KBlock *b); -int kblock_copy(struct KBlock *b, block_idx_t idx1, block_idx_t idx2); + +/** + * Copy one block to another. + * + * This function will copy the content of block \a src to block \a dest. + * + * \note This function is available only on devices opened in buffered mode. + * + * \param b KBlock device. + * \param src source block number. + * \param dest destination block number. + * + * \return 0 if all is OK, EOF on errors. + */ +int kblock_copy(struct KBlock *b, block_idx_t src, block_idx_t dest); int kblock_swLoad(struct KBlock *b, block_idx_t index); int kblock_swStore(struct KBlock *b, block_idx_t index); -- 2.25.1