Diff: SDFileSystem.h

Revision:

0:85fbe134acff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem.h	Sat Aug 26 16:30:14 2017 +0000
@@ -0,0 +1,223 @@
+/* SD/MMC File System Library
+ * Copyright (c) 2016 Neil Thiessen
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SD_FILE_SYSTEM_H
+#define SD_FILE_SYSTEM_H
+
+#include "mbed.h"
+#include "FATFileSystem.h"
+
+/** SDFileSystem class.
+ *  Used for creating a virtual file system for accessing SD/MMC cards via SPI.
+ *
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "SDFileSystem.h"
+ *
+ * //Create an SDFileSystem object
+ * SDFileSystem sd(p5, p6, p7, p20, "sd");
+ *
+ * int main()
+ * {
+ *     //Mount the filesystem
+ *     sd.mount();
+ *
+ *     //Perform a write test
+ *     printf("\nWriting to SD card...");
+ *     FILE *fp = fopen("/sd/sdtest.txt", "w");
+ *     if (fp != NULL) {
+ *         fprintf(fp, "We're writing to an SD card!");
+ *         fclose(fp);
+ *         printf("success!\n");
+ *     } else {
+ *         printf("failed!\n");
+ *     }
+ *
+ *     //Perform a read test
+ *     printf("Reading from SD card...");
+ *     fp = fopen("/sd/sdtest.txt", "r");
+ *     if (fp != NULL) {
+ *         char c = fgetc(fp);
+ *         if (c == 'W')
+ *             printf("success!\n");
+ *         else
+ *             printf("incorrect char (%c)!\n", c);
+ *         fclose(fp);
+ *     } else {
+ *         printf("failed!\n");
+ *     }
+ *
+ *     //Unmount the filesystem
+ *     sd.unmount();
+ * }
+ * @endcode
+ */
+class SDFileSystem : public FATFileSystem
+{
+public:
+    /** Represents the different card detect switch types
+     */
+    enum SwitchType {
+        SWITCH_NONE,    /**< No card detect switch (assumes socket is always occupied) */
+        SWITCH_POS_NO,  /**< Switch shorts to VDD when the socket is occupied (positive logic, normally open) */
+        SWITCH_POS_NC,  /**< Switch shorts to VDD when the socket is empty (positive logic, normally closed) */
+        SWITCH_NEG_NO,  /**< Switch shorts to GND when the socket is occupied (negative logic, normally open) */
+        SWITCH_NEG_NC   /**< Switch shorts to GND when the socket is empty (negative logic, normally closed) */
+    };
+
+    /** Represents the different SD/MMC card types
+     */
+    enum CardType {
+        CARD_NONE,      /**< No card is present */
+        CARD_MMC,       /**< MMC card */
+        CARD_SD,        /**< Standard capacity SD card */
+        CARD_SDHC,      /**< High capacity SD card */
+        CARD_UNKNOWN    /**< Unknown or unsupported card */
+    };
+
+    /** Create a virtual file system for accessing SD/MMC cards via SPI
+     *
+     * @param mosi The SPI data out pin.
+     * @param miso The SPI data in pin.
+     * @param sclk The SPI clock pin.
+     * @param cs The SPI chip select pin.
+     * @param name The name used to access the virtual filesystem.
+     * @param cd The card detect pin.
+     * @param cdtype The type of card detect switch.
+     * @param hz The SPI bus frequency (defaults to 1MHz).
+     */
+    SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name, PinName cd = NC, SwitchType cdtype = SWITCH_NONE, int hz = 1000000);
+
+    /** Determine whether or not a card is present
+     *
+     * @returns
+     *   'true' if a card is present,
+     *   'false' if no card is present.
+     */
+    bool card_present();
+
+    /** Get the detected SD/MMC card type
+     *
+     * @returns The detected card type as a CardType enum.
+     *
+     * @note Valid after the filesystem has been mounted.
+     */
+    SDFileSystem::CardType card_type();
+
+    /** Get whether or not CRC is enabled for commands and data
+     *
+     * @returns
+     *   'true' if CRC is enabled for commands and data,
+     *   'false' if CRC is disabled for commands and data.
+     */
+    bool crc();
+
+    /** Set whether or not CRC is enabled for commands and data
+     *
+     * @param enabled Whether or not to enable CRC for commands and data.
+     */
+    void crc(bool enabled);
+
+    /** Get whether or not 16-bit frames are enabled for data read/write operations
+     *
+     * @returns
+     *   'true' if 16-bit frames will be used during data read/write operations,
+     *   'false' if 8-bit frames will be used during data read/write operations.
+     */
+    bool large_frames();
+
+    /** Set whether or not 16-bit frames are enabled for data read/write operations
+     *
+     * @param enabled Whether or not 16-bit frames are enabled for data read/write operations.
+     */
+    void large_frames(bool enabled);
+
+    /** Get whether or not write validation is enabled for data write operations
+     *
+     * @returns
+     *   'true' if data writes will be verified using CMD13,
+     *   'false' if data writes will not be verified.
+     */
+    bool write_validation();
+
+    /** Set whether or not write validation is enabled for data write operations
+     *
+     * @param enabled Whether or not write validation is enabled for data write operations.
+     */
+    void write_validation(bool enabled);
+
+    virtual int unmount();
+    virtual int disk_initialize();
+    virtual int disk_status();
+    virtual int disk_read(uint8_t* buffer, uint32_t sector, uint32_t count);
+    virtual int disk_write(const uint8_t* buffer, uint32_t sector, uint32_t count);
+    virtual int disk_sync();
+    virtual uint32_t disk_sectors();
+
+private:
+    //Commands
+    enum Command {
+        CMD0 = (0x40 | 0),      /**< GO_IDLE_STATE */
+        CMD1 = (0x40 | 1),      /**< SEND_OP_COND */
+        CMD8 = (0x40 | 8),      /**< SEND_IF_COND */
+        CMD9 = (0x40 | 9),      /**< SEND_CSD */
+        CMD12 = (0x40 | 12),    /**< STOP_TRANSMISSION */
+        CMD13 = (0x40 | 13),    /**< SEND_STATUS */
+        CMD16 = (0x40 | 16),    /**< SET_BLOCKLEN */
+        CMD17 = (0x40 | 17),    /**< READ_SINGLE_BLOCK */
+        CMD18 = (0x40 | 18),    /**< READ_MULTIPLE_BLOCK */
+        ACMD22 = (0x40 | 22),   /**< SEND_NUM_WR_BLOCKS */
+        ACMD23 = (0x40 | 23),   /**< SET_WR_BLK_ERASE_COUNT */
+        CMD24 = (0x40 | 24),    /**< WRITE_BLOCK */
+        CMD25 = (0x40 | 25),    /**< WRITE_MULTIPLE_BLOCK */
+        ACMD41 = (0x40 | 41),   /**< SD_SEND_OP_COND */
+        ACMD42 = (0x40 | 42),   /**< SET_CLR_CARD_DETECT */
+        CMD55 = (0x40 | 55),    /**< APP_CMD */
+        CMD58 = (0x40 | 58),    /**< READ_OCR */
+        CMD59 = (0x40 | 59)     /**< CRC_ON_OFF */
+    };
+
+    //Member variables
+    Timer m_Timer;
+    SPI m_Spi;
+    DigitalOut m_Cs;
+    InterruptIn m_Cd;
+    int m_CdAssert;
+    const int m_FREQ;
+    SDFileSystem::CardType m_CardType;
+    bool m_Crc;
+    bool m_LargeFrames;
+    bool m_WriteValidation;
+    int m_Status;
+
+    //Internal methods
+    void onCardRemoval();
+    void checkSocket();
+    bool waitReady(int timeout);
+    bool select();
+    void deselect();
+    char commandTransaction(char cmd, unsigned int arg, unsigned int* resp = NULL);
+    char writeCommand(char cmd, unsigned int arg, unsigned int* resp = NULL);
+    bool readData(char* buffer, int length);
+    char writeData(const char* buffer, char token);
+    bool readBlock(char* buffer, unsigned int lba);
+    bool readBlocks(char* buffer, unsigned int lba, unsigned int count);
+    bool writeBlock(const char* buffer, unsigned int lba);
+    bool writeBlocks(const char* buffer, unsigned int lba, unsigned int count);
+};
+
+#endif