SDBlockDevice.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2012 ARM Limited
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00020  * SOFTWARE.
00021  */
00022 #ifndef MBED_SD_BLOCK_DEVICE_H
00023 #define MBED_SD_BLOCK_DEVICE_H
00024 
00025 /* If the target has no SPI support then SDCard is not supported */
00026 #ifdef DEVICE_SPI
00027 
00028 #include "BlockDevice.h"
00029 #include "mbed.h"
00030 
00031 
00032 /** Access an SD Card using SPI
00033  *
00034  * @code
00035  * #include "mbed.h"
00036  * #include "SDBlockDevice.h"
00037  *
00038  * SDBlockDevice sd(p5, p6, p7, p12); // mosi, miso, sclk, cs
00039  * uint8_t block[512] = "Hello World!\n";
00040  *
00041  * int main() {
00042  *     sd.init();
00043  *     sd.write(block, 0, 512);
00044  *     sd.read(block, 0, 512);
00045  *     printf("%s", block);
00046  *     sd.deinit();
00047  * }
00048  */
00049 class SDBlockDevice : public BlockDevice {
00050 public:
00051     /** Lifetime of an SD card
00052      */
00053     SDBlockDevice(PinName mosi, PinName miso, PinName sclk, PinName cs);
00054     virtual ~SDBlockDevice();
00055 
00056     /** Initialize a block device
00057      *
00058      *  @return         0 on success or a negative error code on failure
00059      */
00060     virtual int init();
00061 
00062     /** Deinitialize a block device
00063      *
00064      *  @return         0 on success or a negative error code on failure
00065      */
00066     virtual int deinit();
00067 
00068     /** Read blocks from a block device
00069      *
00070      *  @param buffer   Buffer to write blocks to
00071      *  @param addr     Address of block to begin reading from
00072      *  @param size     Size to read in bytes, must be a multiple of read block size
00073      *  @return         0 on success, negative error code on failure
00074      */
00075     virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
00076 
00077     /** Program blocks to a block device
00078      *
00079      *  The blocks must have been erased prior to being programmed
00080      *
00081      *  @param buffer   Buffer of data to write to blocks
00082      *  @param addr     Address of block to begin writing to
00083      *  @param size     Size to write in bytes, must be a multiple of program block size
00084      *  @return         0 on success, negative error code on failure
00085      */
00086     virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
00087 
00088     /** Erase blocks on a block device
00089      *
00090      *  The state of an erased block is undefined until it has been programmed
00091      *
00092      *  @param addr     Address of block to begin erasing
00093      *  @param size     Size to erase in bytes, must be a multiple of erase block size
00094      *  @return         0 on success, negative error code on failure
00095      */
00096     virtual int erase(bd_addr_t addr, bd_size_t size);
00097 
00098     /** Get the size of a readable block
00099      *
00100      *  @return         Size of a readable block in bytes
00101      */
00102     virtual bd_size_t get_read_size() const;
00103 
00104     /** Get the size of a programable block
00105      *
00106      *  @return         Size of a programable block in bytes
00107      *  @note Must be a multiple of the read size
00108      */
00109     virtual bd_size_t get_program_size() const;
00110 
00111     /** Get the size of a eraseable block
00112      *
00113      *  @return         Size of a eraseable block in bytes
00114      *  @note Must be a multiple of the program size
00115      */
00116     virtual bd_size_t get_erase_size() const;
00117 
00118     /** Get the total size of the underlying device
00119      *
00120      *  @return         Size of the underlying device in bytes
00121      */
00122     virtual bd_size_t size() const;
00123 
00124     /** Enable or disable debugging
00125      *
00126      *  @param          State of debugging
00127      */
00128     virtual void debug(bool dbg);
00129 
00130 private:
00131     int _cmd(int cmd, int arg);
00132     int _cmdx(int cmd, int arg);
00133     int _cmd8();
00134     int _cmd58();
00135     int _initialise_card();
00136     int _initialise_card_v1();
00137     int _initialise_card_v2();
00138 
00139     int _read(uint8_t * buffer, uint32_t length);
00140     int _write(const uint8_t *buffer, uint32_t length);
00141     uint32_t _sd_sectors();
00142     uint32_t _sectors;
00143 
00144     uint32_t _init_sck;
00145     uint32_t _transfer_sck;
00146 
00147     SPI _spi;
00148     DigitalOut _cs;
00149     unsigned _block_size;
00150     bool _is_initialized;
00151     bool _dbg;
00152     Mutex _lock;
00153 };
00154 
00155 
00156 #endif  /* DEVICE_SPI */
00157 
00158 #endif  /* MBED_SD_BLOCK_DEVICE_H */