Revision 19:148a0b8d23bc, committed 2011-12-11

Comitter:

samux

Date:

Sun Dec 11 15:42:23 2011 +0000

Parent:

18:08b207d10056

Child:

20:50bf1cd2e2fe

Commit message:

add disk_status to check if init and write protection

Changed in this revision

--- a/USBDevice/USBMSD/USBMSD.cpp	Sun Dec 11 15:22:50 2011 +0000
+++ b/USBDevice/USBMSD/USBMSD.cpp	Sun Dec 11 15:42:23 2011 +0000
@@ -20,6 +20,11 @@
 #include "USBMSD.h"
 #include "USBBusInterface.h"
 
+#define DISK_OK         0x00
+#define NO_INIT         0x01
+#define NO_DISK         0x02
+#define WRITE_PROTECT   0x04
+
 #define CBW_Signature               0x43425355
 #define CSW_Signature               0x53425355
 
@@ -90,18 +95,22 @@
     return success;
 }
 
-
+DigitalOut l1(LED1); 
 bool USBMSD::connect() {
 
     //disk initialization
-    disk_initialize();
+    if (disk_status() & NO_INIT) {
+        if (disk_initialize()) {
+            return false;
+        }
+    }
 
     // get number of blocks
     BlockCount = disk_sectors();
-    
+
     // get memory size
     MemorySize = disk_size();
-    
+
     if (BlockCount >= 0) {
         BlockSize = MemorySize / BlockCount;
         if (BlockSize != 0) {
@@ -212,8 +221,11 @@
         page[addr%BlockSize + i] = buf[i];
 
     // if the array is filled, write it in memory
-    if (!((addr + size)%BlockSize))
-        disk_write((const char *)page, addr/BlockSize);
+    if (!((addr + size)%BlockSize)) {
+        if (!(disk_status() & WRITE_PROTECT)) {
+            disk_write((const char *)page, addr/BlockSize);
+        }
+    }
 
     addr += size;
     length -= size;

--- a/USBDevice/USBMSD/USBMSD.h	Sun Dec 11 15:22:50 2011 +0000
+++ b/USBDevice/USBMSD/USBMSD.h	Sun Dec 11 15:42:23 2011 +0000
@@ -30,9 +30,11 @@
  *   - virtual int disk_initialize(): function to initialize the memory
  *   - virtual int disk_sectors(): return the number of blocks
  *   - virtual int disk_size(): return the memory size
+ *   - virtual int disk_status(): return the status of the storage chip
  *
- * All functions names are compatible with the fat filesystem library. So you can imagine using your own class with either
- * USBMSD or a fat filesystem library.
+ * All functions names are compatible with the fat filesystem library. So you can imagine using your own class with 
+ * USBMSD and the fat filesystem library in the same program. Just be careful because there are two different parts which
+ * will access the sd card. You can do a master/slave system using the disk_status method.
  *
  * Once these functions have been defined, you can call connect() (at the end of the constructor of your class for instance)
  * of USBMSD to connect your mass storage device ;)
@@ -128,6 +130,14 @@
     * @returns memory size
     */
     virtual int disk_size() = 0;
+    
+    
+    /*
+    * To check the status of the storage chip
+    *
+    * @returns status: 0: OK, 1: disk not initialized, 2: no medium in the drive, 4: write protected
+    */
+    virtual int disk_status() = 0;
 
     /*
     * Connect the USB MSD device. Establish disk initialization before really connect the device.

--- a/USBMSD_SD.lib	Sun Dec 11 15:22:50 2011 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +0,0 @@
-http://mbed.org/users/samux/libraries/USBMSD_SD/m20o3f
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBMSD_SD/.lib	Sun Dec 11 15:42:23 2011 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/samux/libraries/USBMSD_SD/m20o3f
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBMSD_SD/USBMSD_SD.cpp	Sun Dec 11 15:42:23 2011 +0000
@@ -0,0 +1,467 @@
+/* mbed USBMSD_SD Library, for providing file access to SD cards
+ * Copyright (c) 2008-2010, sford
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/* Introduction
+ * ------------
+ * SD and MMC cards support a number of interfaces, but common to them all
+ * is one based on SPI. This is the one I'm implmenting because it means
+ * it is much more portable even though not so performant, and we already 
+ * have the mbed SPI Interface!
+ *
+ * The main reference I'm using is Chapter 7, "SPI Mode" of: 
+ *  http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
+ *
+ * SPI Startup
+ * -----------
+ * The SD card powers up in SD mode. The SPI interface mode is selected by
+ * asserting CS low and sending the reset command (CMD0). The card will 
+ * respond with a (R1) response.
+ *
+ * CMD8 is optionally sent to determine the voltage range supported, and 
+ * indirectly determine whether it is a version 1.x SD/non-SD card or 
+ * version 2.x. I'll just ignore this for now.
+ *
+ * ACMD41 is repeatedly issued to initialise the card, until "in idle"
+ * (bit 0) of the R1 response goes to '0', indicating it is initialised.
+ *
+ * You should also indicate whether the host supports High Capicity cards,
+ * and check whether the card is high capacity - i'll also ignore this
+ *
+ * SPI Protocol
+ * ------------
+ * The SD SPI protocol is based on transactions made up of 8-bit words, with
+ * the host starting every bus transaction by asserting the CS signal low. The
+ * card always responds to commands, data blocks and errors.
+ * 
+ * The protocol supports a CRC, but by default it is off (except for the 
+ * first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
+ * I'll leave the CRC off I think! 
+ * 
+ * Standard capacity cards have variable data block sizes, whereas High 
+ * Capacity cards fix the size of data block to 512 bytes. I'll therefore
+ * just always use the Standard Capacity cards with a block size of 512 bytes.
+ * This is set with CMD16.
+ *
+ * You can read and write single blocks (CMD17, CMD25) or multiple blocks 
+ * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
+ * the card gets a read command, it responds with a response token, and then 
+ * a data token or an error.
+ * 
+ * SPI Command Format
+ * ------------------
+ * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
+ *
+ * +---------------+------------+------------+-----------+----------+--------------+
+ * | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 |
+ * +---------------+------------+------------+-----------+----------+--------------+
+ *
+ * As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
+ *
+ * All Application Specific commands shall be preceded with APP_CMD (CMD55).
+ *
+ * SPI Response Format
+ * -------------------
+ * The main response format (R1) is a status byte (normally zero). Key flags:
+ *  idle - 1 if the card is in an idle state/initialising 
+ *  cmd  - 1 if an illegal command code was detected
+ *
+ *    +-------------------------------------------------+
+ * R1 | 0 | arg | addr | seq | crc | cmd | erase | idle |
+ *    +-------------------------------------------------+
+ *
+ * R1b is the same, except it is followed by a busy signal (zeros) until
+ * the first non-zero byte when it is ready again.
+ *
+ * Data Response Token
+ * -------------------
+ * Every data block written to the card is acknowledged by a byte 
+ * response token
+ *
+ * +----------------------+
+ * | xxx | 0 | status | 1 |
+ * +----------------------+
+ *              010 - OK!
+ *              101 - CRC Error
+ *              110 - Write Error
+ *
+ * Single Block Read and Write
+ * ---------------------------
+ *
+ * Block transfers have a byte header, followed by the data, followed
+ * by a 16-bit CRC. In our case, the data will always be 512 bytes.
+ *  
+ * +------+---------+---------+- -  - -+---------+-----------+----------+
+ * | 0xFE | data[0] | data[1] |        | data[n] | crc[15:8] | crc[7:0] | 
+ * +------+---------+---------+- -  - -+---------+-----------+----------+
+ */
+ 
+#include "USBMSD_SD.h"
+
+#define SD_COMMAND_TIMEOUT 5000
+
+USBMSD_SD::USBMSD_SD(PinName mosi, PinName miso, PinName sclk, PinName cs) :
+   _spi(mosi, miso, sclk), _cs(cs) {
+      _cs = 1;
+      //no init
+      _status = 0x01;
+      connect();
+}
+
+#define R1_IDLE_STATE           (1 << 0)
+#define R1_ERASE_RESET          (1 << 1)
+#define R1_ILLEGAL_COMMAND      (1 << 2)
+#define R1_COM_CRC_ERROR        (1 << 3)
+#define R1_ERASE_SEQUENCE_ERROR (1 << 4)
+#define R1_ADDRESS_ERROR        (1 << 5)
+#define R1_PARAMETER_ERROR      (1 << 6)
+
+// Types
+//  - v1.x Standard Capacity
+//  - v2.x Standard Capacity
+//  - v2.x High Capacity
+//  - Not recognised as an SD Card
+
+#define SDCARD_FAIL 0
+#define SDCARD_V1   1
+#define SDCARD_V2   2
+#define SDCARD_V2HC 3
+
+int USBMSD_SD::initialise_card() {
+    // Set to 100kHz for initialisation, and clock card with cs = 1
+    _spi.frequency(100000); 
+    _cs = 1;
+    for(int i=0; i<16; i++) {
+        _spi.write(0xFF);
+    }
+
+    // send CMD0, should return with all zeros except IDLE STATE set (bit 0)
+    if(_cmd(0, 0) != R1_IDLE_STATE) { 
+        fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n");
+        return SDCARD_FAIL;
+    }
+
+    // send CMD8 to determine whther it is ver 2.x
+    int r = _cmd8();
+    if(r == R1_IDLE_STATE) {
+        return initialise_card_v2();
+    } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
+        return initialise_card_v1();
+    } else {
+        fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n");
+        return SDCARD_FAIL;
+    }
+}
+
+int USBMSD_SD::initialise_card_v1() {
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        _cmd(55, 0); 
+        if(_cmd(41, 0) == 0) { 
+            return SDCARD_V1;
+        }
+    }
+
+    fprintf(stderr, "Timeout waiting for v1.x card\n");
+    return SDCARD_FAIL;
+}
+
+int USBMSD_SD::initialise_card_v2() {
+    
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        _cmd(55, 0); 
+        if(_cmd(41, 0) == 0) { 
+            _cmd58();
+            return SDCARD_V2;
+        }
+    }
+
+    fprintf(stderr, "Timeout waiting for v2.x card\n");
+    return SDCARD_FAIL;
+}
+
+int USBMSD_SD::disk_initialize() {
+
+    int i = initialise_card();
+//    printf("init card = %d\n", i);
+//    printf("OK\n");
+
+    _sectors = _sd_sectors();
+
+    // Set block length to 512 (CMD16)
+    if(_cmd(16, 512) != 0) {
+        fprintf(stderr, "Set 512-byte block timed out\n");
+        return 1;
+    }
+        
+    _spi.frequency(5000000); // Set to 5MHz for data transfer
+    // OK
+    _status = 0x00;
+    return 0;
+}
+
+int USBMSD_SD::disk_write(const char *buffer, int block_number) {
+    // set write address for single block (CMD24)
+    if(_cmd(24, block_number * 512) != 0) {
+        return 1;
+    }
+
+    // send the data block
+    _write(buffer, 512);    
+    return 0;    
+}
+
+int USBMSD_SD::disk_read(char *buffer, int block_number) {        
+    // set read address for single block (CMD17)
+    if(_cmd(17, block_number * 512) != 0) {
+        return 1;
+    }
+    
+    // receive the data
+    _read(buffer, 512);
+    return 0;
+}
+
+int USBMSD_SD::disk_status() { return _status; }
+int USBMSD_SD::disk_sync() { return 0; }
+int USBMSD_SD::disk_sectors() { return _sectors; }
+
+// PRIVATE FUNCTIONS
+
+int USBMSD_SD::_cmd(int cmd, int arg) {
+    _cs = 0; 
+
+    // send a command
+    _spi.write(0x40 | cmd);
+    _spi.write(arg >> 24);
+    _spi.write(arg >> 16);
+    _spi.write(arg >> 8);
+    _spi.write(arg >> 0);
+    _spi.write(0x95);
+
+    // wait for the repsonse (response[7] == 0)
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        int response = _spi.write(0xFF);
+        if(!(response & 0x80)) {
+            _cs = 1;
+            _spi.write(0xFF);
+            return response;
+        }
+    }
+    _cs = 1;
+    _spi.write(0xFF);
+    return -1; // timeout
+}
+int USBMSD_SD::_cmdx(int cmd, int arg) {
+    _cs = 0; 
+
+    // send a command
+    _spi.write(0x40 | cmd);
+    _spi.write(arg >> 24);
+    _spi.write(arg >> 16);
+    _spi.write(arg >> 8);
+    _spi.write(arg >> 0);
+    _spi.write(0x95);
+
+    // wait for the repsonse (response[7] == 0)
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        int response = _spi.write(0xFF);
+        if(!(response & 0x80)) {
+            return response;
+        }
+    }
+    _cs = 1;
+    _spi.write(0xFF);
+    return -1; // timeout
+}
+
+
+int USBMSD_SD::_cmd58() {
+    _cs = 0; 
+    int arg = 0;
+    
+    // send a command
+    _spi.write(0x40 | 58);
+    _spi.write(arg >> 24);
+    _spi.write(arg >> 16);
+    _spi.write(arg >> 8);
+    _spi.write(arg >> 0);
+    _spi.write(0x95);
+
+    // wait for the repsonse (response[7] == 0)
+    for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
+        int response = _spi.write(0xFF);
+        if(!(response & 0x80)) {
+            int ocr = _spi.write(0xFF) << 24;
+            ocr |= _spi.write(0xFF) << 16;
+            ocr |= _spi.write(0xFF) << 8;
+            ocr |= _spi.write(0xFF) << 0;
+//            printf("OCR = 0x%08X\n", ocr);
+            _cs = 1;
+            _spi.write(0xFF);
+            return response;
+        }
+    }
+    _cs = 1;
+    _spi.write(0xFF);
+    return -1; // timeout
+}
+
+int USBMSD_SD::_cmd8() {
+    _cs = 0; 
+    
+    // send a command
+    _spi.write(0x40 | 8); // CMD8
+    _spi.write(0x00);     // reserved
+    _spi.write(0x00);     // reserved
+    _spi.write(0x01);     // 3.3v
+    _spi.write(0xAA);     // check pattern
+    _spi.write(0x87);     // crc
+
+    // wait for the repsonse (response[7] == 0)
+    for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) {
+        char response[5];
+        response[0] = _spi.write(0xFF);
+        if(!(response[0] & 0x80)) {
+                for(int j=1; j<5; j++) {
+                    response[i] = _spi.write(0xFF);
+                }
+                _cs = 1;
+                _spi.write(0xFF);
+                return response[0];
+        }
+    }
+    _cs = 1;
+    _spi.write(0xFF);
+    return -1; // timeout
+}
+
+int USBMSD_SD::_read(char *buffer, int length) {
+    _cs = 0;
+
+    // read until start byte (0xFF)
+    while(_spi.write(0xFF) != 0xFE);
+
+    // read data
+    for(int i=0; i<length; i++) {
+        buffer[i] = _spi.write(0xFF);
+    }
+    _spi.write(0xFF); // checksum
+    _spi.write(0xFF);
+
+    _cs = 1;    
+    _spi.write(0xFF);
+    return 0;
+}
+
+int USBMSD_SD::_write(const char *buffer, int length) {
+    _cs = 0;
+    
+    // indicate start of block
+    _spi.write(0xFE);
+    
+    // write the data
+    for(int i=0; i<length; i++) {
+        _spi.write(buffer[i]);
+    }
+    
+    // write the checksum
+    _spi.write(0xFF); 
+    _spi.write(0xFF);
+
+    // check the repsonse token
+    if((_spi.write(0xFF) & 0x1F) != 0x05) {
+        _cs = 1;
+        _spi.write(0xFF);        
+        return 1;
+    }
+
+    // wait for write to finish
+    while(_spi.write(0xFF) == 0);
+
+    _cs = 1; 
+    _spi.write(0xFF);
+    return 0;
+}
+
+static int ext_bits(char *data, int msb, int lsb) {
+    int bits = 0;
+    int size = 1 + msb - lsb; 
+    for(int i=0; i<size; i++) {
+        int position = lsb + i;
+        int byte = 15 - (position >> 3);
+        int bit = position & 0x7;
+        int value = (data[byte] >> bit) & 1;
+        bits |= value << i;
+    }
+    return bits;
+}
+
+int USBMSD_SD::_sd_sectors() {
+
+    // CMD9, Response R2 (R1 byte + 16-byte block read)
+    if(_cmdx(9, 0) != 0) {
+        fprintf(stderr, "Didn't get a response from the disk\n");
+        return 0;
+    }
+    
+    char csd[16];    
+    if(_read(csd, 16) != 0) {
+        fprintf(stderr, "Couldn't read csd response from disk\n");
+        return 0;
+    }
+
+    // csd_structure : csd[127:126]
+    // c_size        : csd[73:62]
+    // c_size_mult   : csd[49:47]
+    // read_bl_len   : csd[83:80] - the *maximum* read block length
+
+    int csd_structure = ext_bits(csd, 127, 126);
+    int c_size = ext_bits(csd, 73, 62);
+    int c_size_mult = ext_bits(csd, 49, 47);
+    int read_bl_len = ext_bits(csd, 83, 80);
+
+//    printf("CSD_STRUCT = %d\n", csd_structure);
+    
+    if(csd_structure != 0) {
+        fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n");
+        return 0;
+    }
+
+    // memory capacity = BLOCKNR * BLOCK_LEN
+    // where
+    //  BLOCKNR = (C_SIZE+1) * MULT
+    //  MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8)
+    //  BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12)         
+
+    int block_len = 1 << read_bl_len;
+    int mult = 1 << (c_size_mult + 2);
+    int blocknr = (c_size + 1) * mult;
+    capacity = blocknr * block_len;
+
+    int blocks = capacity / 512;
+        
+    return blocks;
+}
+
+
+int USBMSD_SD::disk_size() {
+    return capacity;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBMSD_SD/USBMSD_SD.h	Sun Dec 11 15:42:23 2011 +0000
@@ -0,0 +1,85 @@
+/* mbed USBMSD_SD Library, for providing file access to SD cards
+ * Copyright (c) 2008-2010, sford
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef USBMSD_SD_H
+#define USBMSD_SD_H
+
+#include "mbed.h"
+#include "USBMSD.h"
+
+/** Use the SDcard as mass storage device using the USBMSD class
+ *
+ * @code
+ * #include "mbed.h"
+ * #include "USBMSD_SD.h"
+ *
+ * USBMSD_SD sd(p5, p6, p7, p8);
+ *
+ * int main() {
+ *   while(1);
+ * }
+ *
+ * @endcode
+ */
+class USBMSD_SD : public USBMSD {
+public:
+
+    /** Create the File System for accessing an SD Card using SPI
+     *
+     * @param mosi SPI mosi pin connected to SD Card
+     * @param miso SPI miso pin conencted to SD Card
+     * @param sclk SPI sclk pin connected to SD Card
+     * @param cs   DigitalOut pin used as SD Card chip select
+     * @param name The name used to access the virtual filesystem
+     */
+    USBMSD_SD(PinName mosi, PinName miso, PinName sclk, PinName cs);
+    virtual int disk_initialize();
+    virtual int disk_write(const char *buffer, int block_number);
+    virtual int disk_read(char *buffer, int block_number);    
+    virtual int disk_status();
+    virtual int disk_sync();
+    virtual int disk_sectors();
+    virtual int disk_size();
+
+protected:
+
+    int _cmd(int cmd, int arg);
+    int _cmdx(int cmd, int arg);
+    int _cmd8();
+    int _cmd58();
+    int initialise_card();
+    int initialise_card_v1();
+    int initialise_card_v2();
+    
+    int _read(char *buffer, int length);
+    int _write(const char *buffer, int length);
+    int _sd_sectors();
+    int _sectors;
+    
+    int capacity;
+    int _status;
+    
+    SPI _spi;
+    DigitalOut _cs;
+};
+
+#endif