Sowmiya Sivanandham / Mbed 2 deprecated Final_Sonar

seeing i robot - with all the file systems and complete code

Dependencies:   mbed SRF05 Servo CMPS03

SDFileSystem.cpp@1:2bac7b6f3840, 2010-12-17 (annotated)

Committer:
sowmy87
Date:
Fri Dec 17 22:55:25 2010 +0000
Revision:
1:2bac7b6f3840
Parent:
0:ee786e500a3c 
Sensor 1 edited

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sowmy87 0:ee786e500a3c 1 /* mbed SDFileSystem Library, for providing file access to SD cards
sowmy87 0:ee786e500a3c 2 * Copyright (c) 2008-2010, sford
sowmy87 0:ee786e500a3c 3 *
sowmy87 0:ee786e500a3c 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
sowmy87 0:ee786e500a3c 5 * of this software and associated documentation files (the "Software"), to deal
sowmy87 0:ee786e500a3c 6 * in the Software without restriction, including without limitation the rights
sowmy87 0:ee786e500a3c 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
sowmy87 0:ee786e500a3c 8 * copies of the Software, and to permit persons to whom the Software is
sowmy87 0:ee786e500a3c 9 * furnished to do so, subject to the following conditions:
sowmy87 0:ee786e500a3c 10 *
sowmy87 0:ee786e500a3c 11 * The above copyright notice and this permission notice shall be included in
sowmy87 0:ee786e500a3c 12 * all copies or substantial portions of the Software.
sowmy87 0:ee786e500a3c 13 *
sowmy87 0:ee786e500a3c 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
sowmy87 0:ee786e500a3c 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
sowmy87 0:ee786e500a3c 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
sowmy87 0:ee786e500a3c 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
sowmy87 0:ee786e500a3c 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
sowmy87 0:ee786e500a3c 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
sowmy87 0:ee786e500a3c 20 * THE SOFTWARE.
sowmy87 0:ee786e500a3c 21 */
sowmy87 0:ee786e500a3c 22
sowmy87 0:ee786e500a3c 23 /* Introduction
sowmy87 0:ee786e500a3c 24 * ------------
sowmy87 0:ee786e500a3c 25 * SD and MMC cards support a number of interfaces, but common to them all
sowmy87 0:ee786e500a3c 26 * is one based on SPI. This is the one I'm implmenting because it means
sowmy87 0:ee786e500a3c 27 * it is much more portable even though not so performant, and we already
sowmy87 0:ee786e500a3c 28 * have the mbed SPI Interface!
sowmy87 0:ee786e500a3c 29 *
sowmy87 0:ee786e500a3c 30 * The main reference I'm using is Chapter 7, "SPI Mode" of:
sowmy87 0:ee786e500a3c 31 * http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
sowmy87 0:ee786e500a3c 32 *
sowmy87 0:ee786e500a3c 33 * SPI Startup
sowmy87 0:ee786e500a3c 34 * -----------
sowmy87 0:ee786e500a3c 35 * The SD card powers up in SD mode. The SPI interface mode is selected by
sowmy87 0:ee786e500a3c 36 * asserting CS low and sending the reset command (CMD0). The card will
sowmy87 0:ee786e500a3c 37 * respond with a (R1) response.
sowmy87 0:ee786e500a3c 38 *
sowmy87 0:ee786e500a3c 39 * CMD8 is optionally sent to determine the voltage range supported, and
sowmy87 0:ee786e500a3c 40 * indirectly determine whether it is a version 1.x SD/non-SD card or
sowmy87 0:ee786e500a3c 41 * version 2.x. I'll just ignore this for now.
sowmy87 0:ee786e500a3c 42 *
sowmy87 0:ee786e500a3c 43 * ACMD41 is repeatedly issued to initialise the card, until "in idle"
sowmy87 0:ee786e500a3c 44 * (bit 0) of the R1 response goes to '0', indicating it is initialised.
sowmy87 0:ee786e500a3c 45 *
sowmy87 0:ee786e500a3c 46 * You should also indicate whether the host supports High Capicity cards,
sowmy87 0:ee786e500a3c 47 * and check whether the card is high capacity - i'll also ignore this
sowmy87 0:ee786e500a3c 48 *
sowmy87 0:ee786e500a3c 49 * SPI Protocol
sowmy87 0:ee786e500a3c 50 * ------------
sowmy87 0:ee786e500a3c 51 * The SD SPI protocol is based on transactions made up of 8-bit words, with
sowmy87 0:ee786e500a3c 52 * the host starting every bus transaction by asserting the CS signal low. The
sowmy87 0:ee786e500a3c 53 * card always responds to commands, data blocks and errors.
sowmy87 0:ee786e500a3c 54 *
sowmy87 0:ee786e500a3c 55 * The protocol supports a CRC, but by default it is off (except for the
sowmy87 0:ee786e500a3c 56 * first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
sowmy87 0:ee786e500a3c 57 * I'll leave the CRC off I think!
sowmy87 0:ee786e500a3c 58 *
sowmy87 0:ee786e500a3c 59 * Standard capacity cards have variable data block sizes, whereas High
sowmy87 0:ee786e500a3c 60 * Capacity cards fix the size of data block to 512 bytes. I'll therefore
sowmy87 0:ee786e500a3c 61 * just always use the Standard Capacity cards with a block size of 512 bytes.
sowmy87 0:ee786e500a3c 62 * This is set with CMD16.
sowmy87 0:ee786e500a3c 63 *
sowmy87 0:ee786e500a3c 64 * You can read and write single blocks (CMD17, CMD25) or multiple blocks
sowmy87 0:ee786e500a3c 65 * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
sowmy87 0:ee786e500a3c 66 * the card gets a read command, it responds with a response token, and then
sowmy87 0:ee786e500a3c 67 * a data token or an error.
sowmy87 0:ee786e500a3c 68 *
sowmy87 0:ee786e500a3c 69 * SPI Command Format
sowmy87 0:ee786e500a3c 70 * ------------------
sowmy87 0:ee786e500a3c 71 * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
sowmy87 0:ee786e500a3c 72 *
sowmy87 0:ee786e500a3c 73 * +---------------+------------+------------+-----------+----------+--------------+
sowmy87 0:ee786e500a3c 74 * | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 |
sowmy87 0:ee786e500a3c 75 * +---------------+------------+------------+-----------+----------+--------------+
sowmy87 0:ee786e500a3c 76 *
sowmy87 0:ee786e500a3c 77 * As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
sowmy87 0:ee786e500a3c 78 *
sowmy87 0:ee786e500a3c 79 * All Application Specific commands shall be preceded with APP_CMD (CMD55).
sowmy87 0:ee786e500a3c 80 *
sowmy87 0:ee786e500a3c 81 * SPI Response Format
sowmy87 0:ee786e500a3c 82 * -------------------
sowmy87 0:ee786e500a3c 83 * The main response format (R1) is a status byte (normally zero). Key flags:
sowmy87 0:ee786e500a3c 84 * idle - 1 if the card is in an idle state/initialising
sowmy87 0:ee786e500a3c 85 * cmd - 1 if an illegal command code was detected
sowmy87 0:ee786e500a3c 86 *
sowmy87 0:ee786e500a3c 87 * +-------------------------------------------------+
sowmy87 0:ee786e500a3c 88 * R1 | 0 | arg | addr | seq | crc | cmd | erase | idle |
sowmy87 0:ee786e500a3c 89 * +-------------------------------------------------+
sowmy87 0:ee786e500a3c 90 *
sowmy87 0:ee786e500a3c 91 * R1b is the same, except it is followed by a busy signal (zeros) until
sowmy87 0:ee786e500a3c 92 * the first non-zero byte when it is ready again.
sowmy87 0:ee786e500a3c 93 *
sowmy87 0:ee786e500a3c 94 * Data Response Token
sowmy87 0:ee786e500a3c 95 * -------------------
sowmy87 0:ee786e500a3c 96 * Every data block written to the card is acknowledged by a byte
sowmy87 0:ee786e500a3c 97 * response token
sowmy87 0:ee786e500a3c 98 *
sowmy87 0:ee786e500a3c 99 * +----------------------+
sowmy87 0:ee786e500a3c 100 * | xxx | 0 | status | 1 |
sowmy87 0:ee786e500a3c 101 * +----------------------+
sowmy87 0:ee786e500a3c 102 * 010 - OK!
sowmy87 0:ee786e500a3c 103 * 101 - CRC Error
sowmy87 0:ee786e500a3c 104 * 110 - Write Error
sowmy87 0:ee786e500a3c 105 *
sowmy87 0:ee786e500a3c 106 * Single Block Read and Write
sowmy87 0:ee786e500a3c 107 * ---------------------------
sowmy87 0:ee786e500a3c 108 *
sowmy87 0:ee786e500a3c 109 * Block transfers have a byte header, followed by the data, followed
sowmy87 0:ee786e500a3c 110 * by a 16-bit CRC. In our case, the data will always be 512 bytes.
sowmy87 0:ee786e500a3c 111 *
sowmy87 0:ee786e500a3c 112 * +------+---------+---------+- - - -+---------+-----------+----------+
sowmy87 0:ee786e500a3c 113 * | 0xFE | data[0] | data[1] | | data[n] | crc[15:8] | crc[7:0] |
sowmy87 0:ee786e500a3c 114 * +------+---------+---------+- - - -+---------+-----------+----------+
sowmy87 0:ee786e500a3c 115 */
sowmy87 0:ee786e500a3c 116
sowmy87 0:ee786e500a3c 117 #include "SDFileSystem.h"
sowmy87 0:ee786e500a3c 118
sowmy87 0:ee786e500a3c 119 #define SD_COMMAND_TIMEOUT 5000
sowmy87 0:ee786e500a3c 120
sowmy87 0:ee786e500a3c 121 SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
sowmy87 0:ee786e500a3c 122 FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) {
sowmy87 0:ee786e500a3c 123 _cs = 1;
sowmy87 0:ee786e500a3c 124 }
sowmy87 0:ee786e500a3c 125
sowmy87 0:ee786e500a3c 126 #define R1_IDLE_STATE (1 << 0)
sowmy87 0:ee786e500a3c 127 #define R1_ERASE_RESET (1 << 1)
sowmy87 0:ee786e500a3c 128 #define R1_ILLEGAL_COMMAND (1 << 2)
sowmy87 0:ee786e500a3c 129 #define R1_COM_CRC_ERROR (1 << 3)
sowmy87 0:ee786e500a3c 130 #define R1_ERASE_SEQUENCE_ERROR (1 << 4)
sowmy87 0:ee786e500a3c 131 #define R1_ADDRESS_ERROR (1 << 5)
sowmy87 0:ee786e500a3c 132 #define R1_PARAMETER_ERROR (1 << 6)
sowmy87 0:ee786e500a3c 133
sowmy87 0:ee786e500a3c 134 // Types
sowmy87 0:ee786e500a3c 135 // - v1.x Standard Capacity
sowmy87 0:ee786e500a3c 136 // - v2.x Standard Capacity
sowmy87 0:ee786e500a3c 137 // - v2.x High Capacity
sowmy87 0:ee786e500a3c 138 // - Not recognised as an SD Card
sowmy87 0:ee786e500a3c 139
sowmy87 0:ee786e500a3c 140 #define SDCARD_FAIL 0
sowmy87 0:ee786e500a3c 141 #define SDCARD_V1 1
sowmy87 0:ee786e500a3c 142 #define SDCARD_V2 2
sowmy87 0:ee786e500a3c 143 #define SDCARD_V2HC 3
sowmy87 0:ee786e500a3c 144
sowmy87 0:ee786e500a3c 145 int SDFileSystem::initialise_card() {
sowmy87 0:ee786e500a3c 146 // Set to 100kHz for initialisation, and clock card with cs = 1
sowmy87 0:ee786e500a3c 147 _spi.frequency(100000);
sowmy87 0:ee786e500a3c 148 _cs = 1;
sowmy87 0:ee786e500a3c 149 for(int i=0; i<16; i++) {
sowmy87 0:ee786e500a3c 150 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 151 }
sowmy87 0:ee786e500a3c 152
sowmy87 0:ee786e500a3c 153 // send CMD0, should return with all zeros except IDLE STATE set (bit 0)
sowmy87 0:ee786e500a3c 154 if(_cmd(0, 0) != R1_IDLE_STATE) {
sowmy87 0:ee786e500a3c 155 fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n");
sowmy87 0:ee786e500a3c 156 return SDCARD_FAIL;
sowmy87 0:ee786e500a3c 157 }
sowmy87 0:ee786e500a3c 158
sowmy87 0:ee786e500a3c 159 // send CMD8 to determine whther it is ver 2.x
sowmy87 0:ee786e500a3c 160 int r = _cmd8();
sowmy87 0:ee786e500a3c 161 if(r == R1_IDLE_STATE) {
sowmy87 0:ee786e500a3c 162 return initialise_card_v2();
sowmy87 0:ee786e500a3c 163 } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
sowmy87 0:ee786e500a3c 164 return initialise_card_v1();
sowmy87 0:ee786e500a3c 165 } else {
sowmy87 0:ee786e500a3c 166 fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n");
sowmy87 0:ee786e500a3c 167 return SDCARD_FAIL;
sowmy87 0:ee786e500a3c 168 }
sowmy87 0:ee786e500a3c 169 }
sowmy87 0:ee786e500a3c 170
sowmy87 0:ee786e500a3c 171 int SDFileSystem::initialise_card_v1() {
sowmy87 0:ee786e500a3c 172 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
sowmy87 0:ee786e500a3c 173 _cmd(55, 0);
sowmy87 0:ee786e500a3c 174 if(_cmd(41, 0) == 0) {
sowmy87 0:ee786e500a3c 175 return SDCARD_V1;
sowmy87 0:ee786e500a3c 176 }
sowmy87 0:ee786e500a3c 177 }
sowmy87 0:ee786e500a3c 178
sowmy87 0:ee786e500a3c 179 fprintf(stderr, "Timeout waiting for v1.x card\n");
sowmy87 0:ee786e500a3c 180 return SDCARD_FAIL;
sowmy87 0:ee786e500a3c 181 }
sowmy87 0:ee786e500a3c 182
sowmy87 0:ee786e500a3c 183 int SDFileSystem::initialise_card_v2() {
sowmy87 0:ee786e500a3c 184
sowmy87 0:ee786e500a3c 185 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
sowmy87 0:ee786e500a3c 186 _cmd(55, 0);
sowmy87 0:ee786e500a3c 187 if(_cmd(41, 0) == 0) {
sowmy87 0:ee786e500a3c 188 _cmd58();
sowmy87 0:ee786e500a3c 189 return SDCARD_V2;
sowmy87 0:ee786e500a3c 190 }
sowmy87 0:ee786e500a3c 191 }
sowmy87 0:ee786e500a3c 192
sowmy87 0:ee786e500a3c 193 fprintf(stderr, "Timeout waiting for v2.x card\n");
sowmy87 0:ee786e500a3c 194 return SDCARD_FAIL;
sowmy87 0:ee786e500a3c 195 }
sowmy87 0:ee786e500a3c 196
sowmy87 0:ee786e500a3c 197 int SDFileSystem::disk_initialize() {
sowmy87 0:ee786e500a3c 198
sowmy87 0:ee786e500a3c 199 int i = initialise_card();
sowmy87 0:ee786e500a3c 200 // printf("init card = %d\n", i);
sowmy87 0:ee786e500a3c 201 // printf("OK\n");
sowmy87 0:ee786e500a3c 202
sowmy87 0:ee786e500a3c 203 _sectors = _sd_sectors();
sowmy87 0:ee786e500a3c 204
sowmy87 0:ee786e500a3c 205 // Set block length to 512 (CMD16)
sowmy87 0:ee786e500a3c 206 if(_cmd(16, 512) != 0) {
sowmy87 0:ee786e500a3c 207 fprintf(stderr, "Set 512-byte block timed out\n");
sowmy87 0:ee786e500a3c 208 return 1;
sowmy87 0:ee786e500a3c 209 }
sowmy87 0:ee786e500a3c 210
sowmy87 0:ee786e500a3c 211 _spi.frequency(1000000); // Set to 1MHz for data transfer
sowmy87 0:ee786e500a3c 212 return 0;
sowmy87 0:ee786e500a3c 213 }
sowmy87 0:ee786e500a3c 214
sowmy87 0:ee786e500a3c 215 int SDFileSystem::disk_write(const char *buffer, int block_number) {
sowmy87 0:ee786e500a3c 216 // set write address for single block (CMD24)
sowmy87 0:ee786e500a3c 217 if(_cmd(24, block_number * 512) != 0) {
sowmy87 0:ee786e500a3c 218 return 1;
sowmy87 0:ee786e500a3c 219 }
sowmy87 0:ee786e500a3c 220
sowmy87 0:ee786e500a3c 221 // send the data block
sowmy87 0:ee786e500a3c 222 _write(buffer, 512);
sowmy87 0:ee786e500a3c 223 return 0;
sowmy87 0:ee786e500a3c 224 }
sowmy87 0:ee786e500a3c 225
sowmy87 0:ee786e500a3c 226 int SDFileSystem::disk_read(char *buffer, int block_number) {
sowmy87 0:ee786e500a3c 227 // set read address for single block (CMD17)
sowmy87 0:ee786e500a3c 228 if(_cmd(17, block_number * 512) != 0) {
sowmy87 0:ee786e500a3c 229 return 1;
sowmy87 0:ee786e500a3c 230 }
sowmy87 0:ee786e500a3c 231
sowmy87 0:ee786e500a3c 232 // receive the data
sowmy87 0:ee786e500a3c 233 _read(buffer, 512);
sowmy87 0:ee786e500a3c 234 return 0;
sowmy87 0:ee786e500a3c 235 }
sowmy87 0:ee786e500a3c 236
sowmy87 0:ee786e500a3c 237 int SDFileSystem::disk_status() { return 0; }
sowmy87 0:ee786e500a3c 238 int SDFileSystem::disk_sync() { return 0; }
sowmy87 0:ee786e500a3c 239 int SDFileSystem::disk_sectors() { return _sectors; }
sowmy87 0:ee786e500a3c 240
sowmy87 0:ee786e500a3c 241 // PRIVATE FUNCTIONS
sowmy87 0:ee786e500a3c 242
sowmy87 0:ee786e500a3c 243 int SDFileSystem::_cmd(int cmd, int arg) {
sowmy87 0:ee786e500a3c 244 _cs = 0;
sowmy87 0:ee786e500a3c 245
sowmy87 0:ee786e500a3c 246 // send a command
sowmy87 0:ee786e500a3c 247 _spi.write(0x40 | cmd);
sowmy87 0:ee786e500a3c 248 _spi.write(arg >> 24);
sowmy87 0:ee786e500a3c 249 _spi.write(arg >> 16);
sowmy87 0:ee786e500a3c 250 _spi.write(arg >> 8);
sowmy87 0:ee786e500a3c 251 _spi.write(arg >> 0);
sowmy87 0:ee786e500a3c 252 _spi.write(0x95);
sowmy87 0:ee786e500a3c 253
sowmy87 0:ee786e500a3c 254 // wait for the repsonse (response[7] == 0)
sowmy87 0:ee786e500a3c 255 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
sowmy87 0:ee786e500a3c 256 int response = _spi.write(0xFF);
sowmy87 0:ee786e500a3c 257 if(!(response & 0x80)) {
sowmy87 0:ee786e500a3c 258 _cs = 1;
sowmy87 0:ee786e500a3c 259 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 260 return response;
sowmy87 0:ee786e500a3c 261 }
sowmy87 0:ee786e500a3c 262 }
sowmy87 0:ee786e500a3c 263 _cs = 1;
sowmy87 0:ee786e500a3c 264 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 265 return -1; // timeout
sowmy87 0:ee786e500a3c 266 }
sowmy87 0:ee786e500a3c 267 int SDFileSystem::_cmdx(int cmd, int arg) {
sowmy87 0:ee786e500a3c 268 _cs = 0;
sowmy87 0:ee786e500a3c 269
sowmy87 0:ee786e500a3c 270 // send a command
sowmy87 0:ee786e500a3c 271 _spi.write(0x40 | cmd);
sowmy87 0:ee786e500a3c 272 _spi.write(arg >> 24);
sowmy87 0:ee786e500a3c 273 _spi.write(arg >> 16);
sowmy87 0:ee786e500a3c 274 _spi.write(arg >> 8);
sowmy87 0:ee786e500a3c 275 _spi.write(arg >> 0);
sowmy87 0:ee786e500a3c 276 _spi.write(0x95);
sowmy87 0:ee786e500a3c 277
sowmy87 0:ee786e500a3c 278 // wait for the repsonse (response[7] == 0)
sowmy87 0:ee786e500a3c 279 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
sowmy87 0:ee786e500a3c 280 int response = _spi.write(0xFF);
sowmy87 0:ee786e500a3c 281 if(!(response & 0x80)) {
sowmy87 0:ee786e500a3c 282 return response;
sowmy87 0:ee786e500a3c 283 }
sowmy87 0:ee786e500a3c 284 }
sowmy87 0:ee786e500a3c 285 _cs = 1;
sowmy87 0:ee786e500a3c 286 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 287 return -1; // timeout
sowmy87 0:ee786e500a3c 288 }
sowmy87 0:ee786e500a3c 289
sowmy87 0:ee786e500a3c 290
sowmy87 0:ee786e500a3c 291 int SDFileSystem::_cmd58() {
sowmy87 0:ee786e500a3c 292 _cs = 0;
sowmy87 0:ee786e500a3c 293 int arg = 0;
sowmy87 0:ee786e500a3c 294
sowmy87 0:ee786e500a3c 295 // send a command
sowmy87 0:ee786e500a3c 296 _spi.write(0x40 | 58);
sowmy87 0:ee786e500a3c 297 _spi.write(arg >> 24);
sowmy87 0:ee786e500a3c 298 _spi.write(arg >> 16);
sowmy87 0:ee786e500a3c 299 _spi.write(arg >> 8);
sowmy87 0:ee786e500a3c 300 _spi.write(arg >> 0);
sowmy87 0:ee786e500a3c 301 _spi.write(0x95);
sowmy87 0:ee786e500a3c 302
sowmy87 0:ee786e500a3c 303 // wait for the repsonse (response[7] == 0)
sowmy87 0:ee786e500a3c 304 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
sowmy87 0:ee786e500a3c 305 int response = _spi.write(0xFF);
sowmy87 0:ee786e500a3c 306 if(!(response & 0x80)) {
sowmy87 0:ee786e500a3c 307 int ocr = _spi.write(0xFF) << 24;
sowmy87 0:ee786e500a3c 308 ocr |= _spi.write(0xFF) << 16;
sowmy87 0:ee786e500a3c 309 ocr |= _spi.write(0xFF) << 8;
sowmy87 0:ee786e500a3c 310 ocr |= _spi.write(0xFF) << 0;
sowmy87 0:ee786e500a3c 311 // printf("OCR = 0x%08X\n", ocr);
sowmy87 0:ee786e500a3c 312 _cs = 1;
sowmy87 0:ee786e500a3c 313 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 314 return response;
sowmy87 0:ee786e500a3c 315 }
sowmy87 0:ee786e500a3c 316 }
sowmy87 0:ee786e500a3c 317 _cs = 1;
sowmy87 0:ee786e500a3c 318 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 319 return -1; // timeout
sowmy87 0:ee786e500a3c 320 }
sowmy87 0:ee786e500a3c 321
sowmy87 0:ee786e500a3c 322 int SDFileSystem::_cmd8() {
sowmy87 0:ee786e500a3c 323 _cs = 0;
sowmy87 0:ee786e500a3c 324
sowmy87 0:ee786e500a3c 325 // send a command
sowmy87 0:ee786e500a3c 326 _spi.write(0x40 | 8); // CMD8
sowmy87 0:ee786e500a3c 327 _spi.write(0x00); // reserved
sowmy87 0:ee786e500a3c 328 _spi.write(0x00); // reserved
sowmy87 0:ee786e500a3c 329 _spi.write(0x01); // 3.3v
sowmy87 0:ee786e500a3c 330 _spi.write(0xAA); // check pattern
sowmy87 0:ee786e500a3c 331 _spi.write(0x87); // crc
sowmy87 0:ee786e500a3c 332
sowmy87 0:ee786e500a3c 333 // wait for the repsonse (response[7] == 0)
sowmy87 0:ee786e500a3c 334 for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) {
sowmy87 0:ee786e500a3c 335 char response[5];
sowmy87 0:ee786e500a3c 336 response[0] = _spi.write(0xFF);
sowmy87 0:ee786e500a3c 337 if(!(response[0] & 0x80)) {
sowmy87 0:ee786e500a3c 338 for(int j=1; j<5; j++) {
sowmy87 0:ee786e500a3c 339 response[i] = _spi.write(0xFF);
sowmy87 0:ee786e500a3c 340 }
sowmy87 0:ee786e500a3c 341 _cs = 1;
sowmy87 0:ee786e500a3c 342 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 343 return response[0];
sowmy87 0:ee786e500a3c 344 }
sowmy87 0:ee786e500a3c 345 }
sowmy87 0:ee786e500a3c 346 _cs = 1;
sowmy87 0:ee786e500a3c 347 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 348 return -1; // timeout
sowmy87 0:ee786e500a3c 349 }
sowmy87 0:ee786e500a3c 350
sowmy87 0:ee786e500a3c 351 int SDFileSystem::_read(char *buffer, int length) {
sowmy87 0:ee786e500a3c 352 _cs = 0;
sowmy87 0:ee786e500a3c 353
sowmy87 0:ee786e500a3c 354 // read until start byte (0xFF)
sowmy87 0:ee786e500a3c 355 while(_spi.write(0xFF) != 0xFE);
sowmy87 0:ee786e500a3c 356
sowmy87 0:ee786e500a3c 357 // read data
sowmy87 0:ee786e500a3c 358 for(int i=0; i<length; i++) {
sowmy87 0:ee786e500a3c 359 buffer[i] = _spi.write(0xFF);
sowmy87 0:ee786e500a3c 360 }
sowmy87 0:ee786e500a3c 361 _spi.write(0xFF); // checksum
sowmy87 0:ee786e500a3c 362 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 363
sowmy87 0:ee786e500a3c 364 _cs = 1;
sowmy87 0:ee786e500a3c 365 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 366 return 0;
sowmy87 0:ee786e500a3c 367 }
sowmy87 0:ee786e500a3c 368
sowmy87 0:ee786e500a3c 369 int SDFileSystem::_write(const char *buffer, int length) {
sowmy87 0:ee786e500a3c 370 _cs = 0;
sowmy87 0:ee786e500a3c 371
sowmy87 0:ee786e500a3c 372 // indicate start of block
sowmy87 0:ee786e500a3c 373 _spi.write(0xFE);
sowmy87 0:ee786e500a3c 374
sowmy87 0:ee786e500a3c 375 // write the data
sowmy87 0:ee786e500a3c 376 for(int i=0; i<length; i++) {
sowmy87 0:ee786e500a3c 377 _spi.write(buffer[i]);
sowmy87 0:ee786e500a3c 378 }
sowmy87 0:ee786e500a3c 379
sowmy87 0:ee786e500a3c 380 // write the checksum
sowmy87 0:ee786e500a3c 381 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 382 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 383
sowmy87 0:ee786e500a3c 384 // check the repsonse token
sowmy87 0:ee786e500a3c 385 if((_spi.write(0xFF) & 0x1F) != 0x05) {
sowmy87 0:ee786e500a3c 386 _cs = 1;
sowmy87 0:ee786e500a3c 387 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 388 return 1;
sowmy87 0:ee786e500a3c 389 }
sowmy87 0:ee786e500a3c 390
sowmy87 0:ee786e500a3c 391 // wait for write to finish
sowmy87 0:ee786e500a3c 392 while(_spi.write(0xFF) == 0);
sowmy87 0:ee786e500a3c 393
sowmy87 0:ee786e500a3c 394 _cs = 1;
sowmy87 0:ee786e500a3c 395 _spi.write(0xFF);
sowmy87 0:ee786e500a3c 396 return 0;
sowmy87 0:ee786e500a3c 397 }
sowmy87 0:ee786e500a3c 398
sowmy87 0:ee786e500a3c 399 static int ext_bits(char *data, int msb, int lsb) {
sowmy87 0:ee786e500a3c 400 int bits = 0;
sowmy87 0:ee786e500a3c 401 int size = 1 + msb - lsb;
sowmy87 0:ee786e500a3c 402 for(int i=0; i<size; i++) {
sowmy87 0:ee786e500a3c 403 int position = lsb + i;
sowmy87 0:ee786e500a3c 404 int byte = 15 - (position >> 3);
sowmy87 0:ee786e500a3c 405 int bit = position & 0x7;
sowmy87 0:ee786e500a3c 406 int value = (data[byte] >> bit) & 1;
sowmy87 0:ee786e500a3c 407 bits |= value << i;
sowmy87 0:ee786e500a3c 408 }
sowmy87 0:ee786e500a3c 409 return bits;
sowmy87 0:ee786e500a3c 410 }
sowmy87 0:ee786e500a3c 411
sowmy87 0:ee786e500a3c 412 int SDFileSystem::_sd_sectors() {
sowmy87 0:ee786e500a3c 413
sowmy87 0:ee786e500a3c 414 // CMD9, Response R2 (R1 byte + 16-byte block read)
sowmy87 0:ee786e500a3c 415 if(_cmdx(9, 0) != 0) {
sowmy87 0:ee786e500a3c 416 fprintf(stderr, "Didn't get a response from the disk\n");
sowmy87 0:ee786e500a3c 417 return 0;
sowmy87 0:ee786e500a3c 418 }
sowmy87 0:ee786e500a3c 419
sowmy87 0:ee786e500a3c 420 char csd[16];
sowmy87 0:ee786e500a3c 421 if(_read(csd, 16) != 0) {
sowmy87 0:ee786e500a3c 422 fprintf(stderr, "Couldn't read csd response from disk\n");
sowmy87 0:ee786e500a3c 423 return 0;
sowmy87 0:ee786e500a3c 424 }
sowmy87 0:ee786e500a3c 425
sowmy87 0:ee786e500a3c 426 // csd_structure : csd[127:126]
sowmy87 0:ee786e500a3c 427 // c_size : csd[73:62]
sowmy87 0:ee786e500a3c 428 // c_size_mult : csd[49:47]
sowmy87 0:ee786e500a3c 429 // read_bl_len : csd[83:80] - the *maximum* read block length
sowmy87 0:ee786e500a3c 430
sowmy87 0:ee786e500a3c 431 int csd_structure = ext_bits(csd, 127, 126);
sowmy87 0:ee786e500a3c 432 int c_size = ext_bits(csd, 73, 62);
sowmy87 0:ee786e500a3c 433 int c_size_mult = ext_bits(csd, 49, 47);
sowmy87 0:ee786e500a3c 434 int read_bl_len = ext_bits(csd, 83, 80);
sowmy87 0:ee786e500a3c 435
sowmy87 0:ee786e500a3c 436 // printf("CSD_STRUCT = %d\n", csd_structure);
sowmy87 0:ee786e500a3c 437
sowmy87 0:ee786e500a3c 438 if(csd_structure != 0) {
sowmy87 0:ee786e500a3c 439 fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n");
sowmy87 0:ee786e500a3c 440 return 0;
sowmy87 0:ee786e500a3c 441 }
sowmy87 0:ee786e500a3c 442
sowmy87 0:ee786e500a3c 443 // memory capacity = BLOCKNR * BLOCK_LEN
sowmy87 0:ee786e500a3c 444 // where
sowmy87 0:ee786e500a3c 445 // BLOCKNR = (C_SIZE+1) * MULT
sowmy87 0:ee786e500a3c 446 // MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8)
sowmy87 0:ee786e500a3c 447 // BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12)
sowmy87 0:ee786e500a3c 448
sowmy87 0:ee786e500a3c 449 int block_len = 1 << read_bl_len;
sowmy87 0:ee786e500a3c 450 int mult = 1 << (c_size_mult + 2);
sowmy87 0:ee786e500a3c 451 int blocknr = (c_size + 1) * mult;
sowmy87 0:ee786e500a3c 452 int capacity = blocknr * block_len;
sowmy87 0:ee786e500a3c 453
sowmy87 0:ee786e500a3c 454 int blocks = capacity / 512;
sowmy87 0:ee786e500a3c 455
sowmy87 0:ee786e500a3c 456 return blocks;
sowmy87 0:ee786e500a3c 457 }