Klaus Bu
/
SDHCFileSystem
SDHC support till 32GB
Revision 0:90601632692f, committed 2010-07-24
- Comitter:
- xxll
- Date:
- Sat Jul 24 19:45:29 2010 +0000
- Commit message:
Changed in this revision
diff -r 000000000000 -r 90601632692f FATFileSystem.lib --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/FATFileSystem.lib Sat Jul 24 19:45:29 2010 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_unsupported/code/fatfilesystem/ \ No newline at end of file
diff -r 000000000000 -r 90601632692f SDHCFileSystem.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/SDHCFileSystem.cpp Sat Jul 24 19:45:29 2010 +0000 @@ -0,0 +1,495 @@ +/* mbed SDFileSystem 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] | + * +------+---------+---------+- - - -+---------+-----------+----------+ + */ + + /* + * Comment: Changes for SDHC support till 32GB + * Name: KB + * Date: 07/24/2010 + * Release: 0.1 + */ + +#include "SDHCFileSystem.h" + +#define DEBUG +#define SD_COMMAND_TIMEOUT 5000 + + +SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) : + FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) { + _cs = 1; +} + +#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 SDFileSystem::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 SDFileSystem::initialise_card_v1() { + for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { + _cmd(55, 0); + if(_cmd(41, 0) == 0) { + cdv = 512; + #ifdef DEBUG + printf("\n\rInit: SEDCARD_V1\n\r"); + #endif + return SDCARD_V1; + } + } + + fprintf(stderr, "Timeout waiting for v1.x card\n"); + return SDCARD_FAIL; +} + +int SDFileSystem::initialise_card_v2() { + + for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { + wait_ms(50); + _cmd58(); + _cmd(55, 0); + if(_cmd(41, 0x40000000) == 0) { + _cmd58(); + #ifdef DEBUG + printf("\n\rInit: SDCARD_V2\n\r"); + #endif + cdv = 1; + return SDCARD_V2; + } + } + + fprintf(stderr, "Timeout waiting for v2.x card\n"); + return SDCARD_FAIL; +} + +int SDFileSystem::disk_initialize() { + + int i = initialise_card(); + #ifdef DEBUG + printf("init card = %d\n", i); + #endif + _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(1000000); // Set to 1MHz for data transfer + return 0; +} + +int SDFileSystem::disk_write(const char *buffer, int block_number) { + // set write address for single block (CMD24) + if(_cmd(24, block_number * cdv) != 0) { + return 1; + } + + // send the data block + _write(buffer, 512); + return 0; +} + +int SDFileSystem::disk_read(char *buffer, int block_number) { + // set read address for single block (CMD17) + if(_cmd(17, block_number * cdv) != 0) { + return 1; + } + + // receive the data + _read(buffer, 512); + return 0; +} + +int SDFileSystem::disk_status() { return 0; } +int SDFileSystem::disk_sync() { return 0; } +int SDFileSystem::disk_sectors() { return _sectors; } + +// PRIVATE FUNCTIONS + +int SDFileSystem::_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 SDFileSystem::_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 SDFileSystem::_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 SDFileSystem::_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 SDFileSystem::_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 SDFileSystem::_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 SDFileSystem::_sd_sectors() { + + int c_size, c_size_mult, read_bl_len; + int block_len, mult, blocknr, capacity; + int blocks, hc_c_size; + uint64_t hc_capacity; + + // 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); + + #ifdef DEBUG + printf("\n\rCSD_STRUCT = %d\n", csd_structure); + #endif + + switch (csd_structure){ + case 0: + cdv = 512; + c_size = ext_bits(csd, 73, 62); + c_size_mult = ext_bits(csd, 49, 47); + read_bl_len = ext_bits(csd, 83, 80); + + block_len = 1 << read_bl_len; + mult = 1 << (c_size_mult + 2); + blocknr = (c_size + 1) * mult; + capacity = blocknr * block_len; + blocks = capacity / 512; + #ifdef DEBUG + printf("\n\rSDCard\n\rc_size: %.4X \n\rcapacity: %.ld \n\rsectors: %d\n\r", c_size, capacity, blocks); + #endif + break; + + case 1: + cdv = 1; + hc_c_size = ext_bits(csd, 63, 48); + int hc_read_bl_len = ext_bits(csd, 83, 80); + hc_capacity = hc_c_size+1; + blocks = (hc_c_size+1)*1024; + #ifdef DEBUG + printf("\n\rSDHC Card \n\rhc_c_size: %.4X \n\rcapacity: %.lld \n\rsectors: %d\n\r", hc_c_size, hc_capacity*512*1024, blocks); + #endif + break; + + default: + fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n"); + return 0; + break; + }; + return blocks; +}
diff -r 000000000000 -r 90601632692f SDHCFileSystem.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/SDHCFileSystem.h Sat Jul 24 19:45:29 2010 +0000 @@ -0,0 +1,86 @@ +/* mbed SDFileSystem 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 MBED_SDHCFILESYSTEM_H +#define MBED_SDHCFILESYSTEM_H + +#include "mbed.h" +#include "FATFileSystem.h" + +/* Double Words */ +typedef unsigned long long uint64_t; +typedef long long sint64_t; + +/** Access the filesystem on an SD Card using SPI + * + * @code + * #include "mbed.h" + * #include "SDFileSystem.h" + * + * SDFileSystem sd(p5, p6, p7, p12, "sd"); // mosi, miso, sclk, cs + * + * int main() { + * FILE *fp = fopen("/sd/myfile.txt", "w"); + * fprintf(fp, "Hello World!\n"); + * fclose(fp); + * } + */ +class SDFileSystem : public FATFileSystem { +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 + */ + SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name); + 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(); + +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; + + SPI _spi; + DigitalOut _cs; + int cdv; +}; + +#endif
diff -r 000000000000 -r 90601632692f main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Sat Jul 24 19:45:29 2010 +0000 @@ -0,0 +1,12 @@ + #include "mbed.h" + #include "string" + #include "SDHCFileSystem.h" + + SDFileSystem sd(p5, p6, p7, p8, "sd"); // mosi, miso, sclk, cs + + int main() { + + FILE *fp = fopen("/sd/myfile.txt", "w"); + fprintf(fp, "\n\rHello World!\n\r"); + fclose(fp); + } \ No newline at end of file
diff -r 000000000000 -r 90601632692f mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Sat Jul 24 19:45:29 2010 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/9114680c05da