SDFileSystem.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_SDFILESYSTEM_H
00023 #define MBED_SDFILESYSTEM_H
00024 
00025 #include "mbed.h"
00026 #include "FATFileSystem.h"
00027 #include <stdint.h>
00028 
00029 /** Access the filesystem on an SD Card using SPI
00030  *
00031  * @code
00032  * #include "mbed.h"
00033  * #include "SDFileSystem.h"
00034  *
00035  * SDFileSystem sd(p5, p6, p7, p12, "sd"); // mosi, miso, sclk, cs
00036  *
00037  * int main() {
00038  *     FILE *fp = fopen("/sd/myfile.txt", "w");
00039  *     fprintf(fp, "Hello World!\n");
00040  *     fclose(fp);
00041  * }
00042  */
00043 class SDFileSystem : public FATFileSystem {
00044 public:
00045 
00046     /** Create the File System for accessing an SD Card using SPI
00047      *
00048      * @param mosi SPI mosi pin connected to SD Card
00049      * @param miso SPI miso pin conencted to SD Card
00050      * @param sclk SPI sclk pin connected to SD Card
00051      * @param cs   DigitalOut pin used as SD Card chip select
00052      * @param name The name used to access the virtual filesystem
00053      */
00054     SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name);
00055     virtual int disk_initialize();
00056     virtual int disk_status();
00057     virtual int disk_read(uint8_t* buffer, uint32_t block_number, uint32_t count);
00058     virtual int disk_write(const uint8_t* buffer, uint32_t block_number, uint32_t count);
00059     virtual int disk_sync();
00060     virtual uint32_t disk_sectors();
00061 
00062 protected:
00063 
00064     int _cmd(int cmd, int arg);
00065     int _cmdx(int cmd, int arg);
00066     int _cmd8();
00067     int _cmd58();
00068     int initialise_card();
00069     int initialise_card_v1();
00070     int initialise_card_v2();
00071 
00072     int _read(uint8_t * buffer, uint32_t length);
00073     int _write(const uint8_t *buffer, uint32_t length);
00074     uint32_t _sd_sectors();
00075     uint32_t _sectors;
00076 
00077     void set_init_sck(uint32_t sck) { _init_sck = sck; }
00078     // Note: The highest SPI clock rate is 20 MHz for MMC and 25 MHz for SD
00079     void set_transfer_sck(uint32_t sck) { _transfer_sck = sck; }
00080     uint32_t _init_sck;
00081     uint32_t _transfer_sck;
00082 
00083     SPI _spi;
00084     DigitalOut _cs;
00085     int cdv;
00086     int _is_initialized;
00087 };
00088 
00089 #endif