Yuji Notsu / Mbed 2 deprecated MARMEX_Oled_GPS_6

test

Dependencies:   FatFileSystem TextLCD mbed

SDFileSystem.cpp@0:2c37ad282618, 2012-09-18 (annotated)

Committer:
y_notsu
Date:
Tue Sep 18 07:24:22 2012 +0000
Revision:
0:2c37ad282618
test

Who changed what in which revision?

UserRevisionLine numberNew contents of line
y_notsu 0:2c37ad282618 1 /* mbed SDFileSystem Library, for providing file access to SD cards
y_notsu 0:2c37ad282618 2 * Copyright (c) 2008-2010, sford
y_notsu 0:2c37ad282618 3 *
y_notsu 0:2c37ad282618 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
y_notsu 0:2c37ad282618 5 * of this software and associated documentation files (the "Software"), to deal
y_notsu 0:2c37ad282618 6 * in the Software without restriction, including without limitation the rights
y_notsu 0:2c37ad282618 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
y_notsu 0:2c37ad282618 8 * copies of the Software, and to permit persons to whom the Software is
y_notsu 0:2c37ad282618 9 * furnished to do so, subject to the following conditions:
y_notsu 0:2c37ad282618 10 *
y_notsu 0:2c37ad282618 11 * The above copyright notice and this permission notice shall be included in
y_notsu 0:2c37ad282618 12 * all copies or substantial portions of the Software.
y_notsu 0:2c37ad282618 13 *
y_notsu 0:2c37ad282618 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
y_notsu 0:2c37ad282618 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
y_notsu 0:2c37ad282618 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
y_notsu 0:2c37ad282618 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
y_notsu 0:2c37ad282618 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
y_notsu 0:2c37ad282618 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
y_notsu 0:2c37ad282618 20 * THE SOFTWARE.
y_notsu 0:2c37ad282618 21 */
y_notsu 0:2c37ad282618 22
y_notsu 0:2c37ad282618 23 /* Introduction
y_notsu 0:2c37ad282618 24 * ------------
y_notsu 0:2c37ad282618 25 * SD and MMC cards support a number of interfaces, but common to them all
y_notsu 0:2c37ad282618 26 * is one based on SPI. This is the one I'm implmenting because it means
y_notsu 0:2c37ad282618 27 * it is much more portable even though not so performant, and we already
y_notsu 0:2c37ad282618 28 * have the mbed SPI Interface!
y_notsu 0:2c37ad282618 29 *
y_notsu 0:2c37ad282618 30 * The main reference I'm using is Chapter 7, "SPI Mode" of:
y_notsu 0:2c37ad282618 31 * http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
y_notsu 0:2c37ad282618 32 *
y_notsu 0:2c37ad282618 33 * SPI Startup
y_notsu 0:2c37ad282618 34 * -----------
y_notsu 0:2c37ad282618 35 * The SD card powers up in SD mode. The SPI interface mode is selected by
y_notsu 0:2c37ad282618 36 * asserting CS low and sending the reset command (CMD0). The card will
y_notsu 0:2c37ad282618 37 * respond with a (R1) response.
y_notsu 0:2c37ad282618 38 *
y_notsu 0:2c37ad282618 39 * CMD8 is optionally sent to determine the voltage range supported, and
y_notsu 0:2c37ad282618 40 * indirectly determine whether it is a version 1.x SD/non-SD card or
y_notsu 0:2c37ad282618 41 * version 2.x. I'll just ignore this for now.
y_notsu 0:2c37ad282618 42 *
y_notsu 0:2c37ad282618 43 * ACMD41 is repeatedly issued to initialise the card, until "in idle"
y_notsu 0:2c37ad282618 44 * (bit 0) of the R1 response goes to '0', indicating it is initialised.
y_notsu 0:2c37ad282618 45 *
y_notsu 0:2c37ad282618 46 * You should also indicate whether the host supports High Capicity cards,
y_notsu 0:2c37ad282618 47 * and check whether the card is high capacity - i'll also ignore this
y_notsu 0:2c37ad282618 48 *
y_notsu 0:2c37ad282618 49 * SPI Protocol
y_notsu 0:2c37ad282618 50 * ------------
y_notsu 0:2c37ad282618 51 * The SD SPI protocol is based on transactions made up of 8-bit words, with
y_notsu 0:2c37ad282618 52 * the host starting every bus transaction by asserting the CS signal low. The
y_notsu 0:2c37ad282618 53 * card always responds to commands, data blocks and errors.
y_notsu 0:2c37ad282618 54 *
y_notsu 0:2c37ad282618 55 * The protocol supports a CRC, but by default it is off (except for the
y_notsu 0:2c37ad282618 56 * first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
y_notsu 0:2c37ad282618 57 * I'll leave the CRC off I think!
y_notsu 0:2c37ad282618 58 *
y_notsu 0:2c37ad282618 59 * Standard capacity cards have variable data block sizes, whereas High
y_notsu 0:2c37ad282618 60 * Capacity cards fix the size of data block to 512 bytes. I'll therefore
y_notsu 0:2c37ad282618 61 * just always use the Standard Capacity cards with a block size of 512 bytes.
y_notsu 0:2c37ad282618 62 * This is set with CMD16.
y_notsu 0:2c37ad282618 63 *
y_notsu 0:2c37ad282618 64 * You can read and write single blocks (CMD17, CMD25) or multiple blocks
y_notsu 0:2c37ad282618 65 * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
y_notsu 0:2c37ad282618 66 * the card gets a read command, it responds with a response token, and then
y_notsu 0:2c37ad282618 67 * a data token or an error.
y_notsu 0:2c37ad282618 68 *
y_notsu 0:2c37ad282618 69 * SPI Command Format
y_notsu 0:2c37ad282618 70 * ------------------
y_notsu 0:2c37ad282618 71 * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
y_notsu 0:2c37ad282618 72 *
y_notsu 0:2c37ad282618 73 * +---------------+------------+------------+-----------+----------+--------------+
y_notsu 0:2c37ad282618 74 * | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 |
y_notsu 0:2c37ad282618 75 * +---------------+------------+------------+-----------+----------+--------------+
y_notsu 0:2c37ad282618 76 *
y_notsu 0:2c37ad282618 77 * As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
y_notsu 0:2c37ad282618 78 *
y_notsu 0:2c37ad282618 79 * All Application Specific commands shall be preceded with APP_CMD (CMD55).
y_notsu 0:2c37ad282618 80 *
y_notsu 0:2c37ad282618 81 * SPI Response Format
y_notsu 0:2c37ad282618 82 * -------------------
y_notsu 0:2c37ad282618 83 * The main response format (R1) is a status byte (normally zero). Key flags:
y_notsu 0:2c37ad282618 84 * idle - 1 if the card is in an idle state/initialising
y_notsu 0:2c37ad282618 85 * cmd - 1 if an illegal command code was detected
y_notsu 0:2c37ad282618 86 *
y_notsu 0:2c37ad282618 87 * +-------------------------------------------------+
y_notsu 0:2c37ad282618 88 * R1 | 0 | arg | addr | seq | crc | cmd | erase | idle |
y_notsu 0:2c37ad282618 89 * +-------------------------------------------------+
y_notsu 0:2c37ad282618 90 *
y_notsu 0:2c37ad282618 91 * R1b is the same, except it is followed by a busy signal (zeros) until
y_notsu 0:2c37ad282618 92 * the first non-zero byte when it is ready again.
y_notsu 0:2c37ad282618 93 *
y_notsu 0:2c37ad282618 94 * Data Response Token
y_notsu 0:2c37ad282618 95 * -------------------
y_notsu 0:2c37ad282618 96 * Every data block written to the card is acknowledged by a byte
y_notsu 0:2c37ad282618 97 * response token
y_notsu 0:2c37ad282618 98 *
y_notsu 0:2c37ad282618 99 * +----------------------+
y_notsu 0:2c37ad282618 100 * | xxx | 0 | status | 1 |
y_notsu 0:2c37ad282618 101 * +----------------------+
y_notsu 0:2c37ad282618 102 * 010 - OK!
y_notsu 0:2c37ad282618 103 * 101 - CRC Error
y_notsu 0:2c37ad282618 104 * 110 - Write Error
y_notsu 0:2c37ad282618 105 *
y_notsu 0:2c37ad282618 106 * Single Block Read and Write
y_notsu 0:2c37ad282618 107 * ---------------------------
y_notsu 0:2c37ad282618 108 *
y_notsu 0:2c37ad282618 109 * Block transfers have a byte header, followed by the data, followed
y_notsu 0:2c37ad282618 110 * by a 16-bit CRC. In our case, the data will always be 512 bytes.
y_notsu 0:2c37ad282618 111 *
y_notsu 0:2c37ad282618 112 * +------+---------+---------+- - - -+---------+-----------+----------+
y_notsu 0:2c37ad282618 113 * | 0xFE | data[0] | data[1] | | data[n] | crc[15:8] | crc[7:0] |
y_notsu 0:2c37ad282618 114 * +------+---------+---------+- - - -+---------+-----------+----------+
y_notsu 0:2c37ad282618 115 */
y_notsu 0:2c37ad282618 116
y_notsu 0:2c37ad282618 117 #include "SDFileSystem.h"
y_notsu 0:2c37ad282618 118
y_notsu 0:2c37ad282618 119 #define SD_COMMAND_TIMEOUT 5000
y_notsu 0:2c37ad282618 120
y_notsu 0:2c37ad282618 121 SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
y_notsu 0:2c37ad282618 122 FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) {
y_notsu 0:2c37ad282618 123 _cs = 1;
y_notsu 0:2c37ad282618 124 }
y_notsu 0:2c37ad282618 125
y_notsu 0:2c37ad282618 126 #define R1_IDLE_STATE (1 << 0)
y_notsu 0:2c37ad282618 127 #define R1_ERASE_RESET (1 << 1)
y_notsu 0:2c37ad282618 128 #define R1_ILLEGAL_COMMAND (1 << 2)
y_notsu 0:2c37ad282618 129 #define R1_COM_CRC_ERROR (1 << 3)
y_notsu 0:2c37ad282618 130 #define R1_ERASE_SEQUENCE_ERROR (1 << 4)
y_notsu 0:2c37ad282618 131 #define R1_ADDRESS_ERROR (1 << 5)
y_notsu 0:2c37ad282618 132 #define R1_PARAMETER_ERROR (1 << 6)
y_notsu 0:2c37ad282618 133
y_notsu 0:2c37ad282618 134 // Types
y_notsu 0:2c37ad282618 135 // - v1.x Standard Capacity
y_notsu 0:2c37ad282618 136 // - v2.x Standard Capacity
y_notsu 0:2c37ad282618 137 // - v2.x High Capacity
y_notsu 0:2c37ad282618 138 // - Not recognised as an SD Card
y_notsu 0:2c37ad282618 139
y_notsu 0:2c37ad282618 140 #define SDCARD_FAIL 0
y_notsu 0:2c37ad282618 141 #define SDCARD_V1 1
y_notsu 0:2c37ad282618 142 #define SDCARD_V2 2
y_notsu 0:2c37ad282618 143 #define SDCARD_V2HC 3
y_notsu 0:2c37ad282618 144
y_notsu 0:2c37ad282618 145 int SDFileSystem::initialise_card() {
y_notsu 0:2c37ad282618 146 // Set to 100kHz for initialisation, and clock card with cs = 1
y_notsu 0:2c37ad282618 147 _spi.frequency(100000);
y_notsu 0:2c37ad282618 148 _cs = 1;
y_notsu 0:2c37ad282618 149 for(int i=0; i<16; i++) {
y_notsu 0:2c37ad282618 150 _spi.write(0xFF);
y_notsu 0:2c37ad282618 151 }
y_notsu 0:2c37ad282618 152
y_notsu 0:2c37ad282618 153 // send CMD0, should return with all zeros except IDLE STATE set (bit 0)
y_notsu 0:2c37ad282618 154 if(_cmd(0, 0) != R1_IDLE_STATE) {
y_notsu 0:2c37ad282618 155 fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n");
y_notsu 0:2c37ad282618 156 return SDCARD_FAIL;
y_notsu 0:2c37ad282618 157 }
y_notsu 0:2c37ad282618 158
y_notsu 0:2c37ad282618 159 // send CMD8 to determine whther it is ver 2.x
y_notsu 0:2c37ad282618 160 int r = _cmd8();
y_notsu 0:2c37ad282618 161 if(r == R1_IDLE_STATE) {
y_notsu 0:2c37ad282618 162 return initialise_card_v2();
y_notsu 0:2c37ad282618 163 } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
y_notsu 0:2c37ad282618 164 return initialise_card_v1();
y_notsu 0:2c37ad282618 165 } else {
y_notsu 0:2c37ad282618 166 fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n");
y_notsu 0:2c37ad282618 167 return SDCARD_FAIL;
y_notsu 0:2c37ad282618 168 }
y_notsu 0:2c37ad282618 169 }
y_notsu 0:2c37ad282618 170
y_notsu 0:2c37ad282618 171 int SDFileSystem::initialise_card_v1() {
y_notsu 0:2c37ad282618 172 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
y_notsu 0:2c37ad282618 173 _cmd(55, 0);
y_notsu 0:2c37ad282618 174 if(_cmd(41, 0) == 0) {
y_notsu 0:2c37ad282618 175 return SDCARD_V1;
y_notsu 0:2c37ad282618 176 }
y_notsu 0:2c37ad282618 177 }
y_notsu 0:2c37ad282618 178
y_notsu 0:2c37ad282618 179 fprintf(stderr, "Timeout waiting for v1.x card\n");
y_notsu 0:2c37ad282618 180 return SDCARD_FAIL;
y_notsu 0:2c37ad282618 181 }
y_notsu 0:2c37ad282618 182
y_notsu 0:2c37ad282618 183 int SDFileSystem::initialise_card_v2() {
y_notsu 0:2c37ad282618 184
y_notsu 0:2c37ad282618 185 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
y_notsu 0:2c37ad282618 186 _cmd(55, 0);
y_notsu 0:2c37ad282618 187 if(_cmd(41, 0) == 0) {
y_notsu 0:2c37ad282618 188 _cmd58();
y_notsu 0:2c37ad282618 189 return SDCARD_V2;
y_notsu 0:2c37ad282618 190 }
y_notsu 0:2c37ad282618 191 }
y_notsu 0:2c37ad282618 192
y_notsu 0:2c37ad282618 193 fprintf(stderr, "Timeout waiting for v2.x card\n");
y_notsu 0:2c37ad282618 194 return SDCARD_FAIL;
y_notsu 0:2c37ad282618 195 }
y_notsu 0:2c37ad282618 196
y_notsu 0:2c37ad282618 197 int SDFileSystem::disk_initialize() {
y_notsu 0:2c37ad282618 198
y_notsu 0:2c37ad282618 199 int i = initialise_card();
y_notsu 0:2c37ad282618 200 // printf("init card = %d\n", i);
y_notsu 0:2c37ad282618 201 // printf("OK\n");
y_notsu 0:2c37ad282618 202
y_notsu 0:2c37ad282618 203 _sectors = _sd_sectors();
y_notsu 0:2c37ad282618 204
y_notsu 0:2c37ad282618 205 // Set block length to 512 (CMD16)
y_notsu 0:2c37ad282618 206 if(_cmd(16, 512) != 0) {
y_notsu 0:2c37ad282618 207 fprintf(stderr, "Set 512-byte block timed out\n");
y_notsu 0:2c37ad282618 208 return 1;
y_notsu 0:2c37ad282618 209 }
y_notsu 0:2c37ad282618 210
y_notsu 0:2c37ad282618 211 // _spi.frequency(1000000); // Set to 1MHz for data transfer
y_notsu 0:2c37ad282618 212 _spi.frequency(5000000); // Set to 1MHz for data transfer
y_notsu 0:2c37ad282618 213 return 0;
y_notsu 0:2c37ad282618 214 }
y_notsu 0:2c37ad282618 215
y_notsu 0:2c37ad282618 216 int SDFileSystem::disk_write(const char *buffer, int block_number) {
y_notsu 0:2c37ad282618 217 // set write address for single block (CMD24)
y_notsu 0:2c37ad282618 218 if(_cmd(24, block_number * 512) != 0) {
y_notsu 0:2c37ad282618 219 return 1;
y_notsu 0:2c37ad282618 220 }
y_notsu 0:2c37ad282618 221
y_notsu 0:2c37ad282618 222 // send the data block
y_notsu 0:2c37ad282618 223 _write(buffer, 512);
y_notsu 0:2c37ad282618 224 return 0;
y_notsu 0:2c37ad282618 225 }
y_notsu 0:2c37ad282618 226
y_notsu 0:2c37ad282618 227 int SDFileSystem::disk_read(char *buffer, int block_number) {
y_notsu 0:2c37ad282618 228 // set read address for single block (CMD17)
y_notsu 0:2c37ad282618 229 if(_cmd(17, block_number * 512) != 0) {
y_notsu 0:2c37ad282618 230 return 1;
y_notsu 0:2c37ad282618 231 }
y_notsu 0:2c37ad282618 232
y_notsu 0:2c37ad282618 233 // receive the data
y_notsu 0:2c37ad282618 234 _read(buffer, 512);
y_notsu 0:2c37ad282618 235 return 0;
y_notsu 0:2c37ad282618 236 }
y_notsu 0:2c37ad282618 237
y_notsu 0:2c37ad282618 238 int SDFileSystem::disk_status() { return 0; }
y_notsu 0:2c37ad282618 239 int SDFileSystem::disk_sync() { return 0; }
y_notsu 0:2c37ad282618 240 int SDFileSystem::disk_sectors() { return _sectors; }
y_notsu 0:2c37ad282618 241
y_notsu 0:2c37ad282618 242 // PRIVATE FUNCTIONS
y_notsu 0:2c37ad282618 243
y_notsu 0:2c37ad282618 244 int SDFileSystem::_cmd(int cmd, int arg) {
y_notsu 0:2c37ad282618 245 _cs = 0;
y_notsu 0:2c37ad282618 246
y_notsu 0:2c37ad282618 247 // send a command
y_notsu 0:2c37ad282618 248 _spi.write(0x40 | cmd);
y_notsu 0:2c37ad282618 249 _spi.write(arg >> 24);
y_notsu 0:2c37ad282618 250 _spi.write(arg >> 16);
y_notsu 0:2c37ad282618 251 _spi.write(arg >> 8);
y_notsu 0:2c37ad282618 252 _spi.write(arg >> 0);
y_notsu 0:2c37ad282618 253 _spi.write(0x95);
y_notsu 0:2c37ad282618 254
y_notsu 0:2c37ad282618 255 // wait for the repsonse (response[7] == 0)
y_notsu 0:2c37ad282618 256 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
y_notsu 0:2c37ad282618 257 int response = _spi.write(0xFF);
y_notsu 0:2c37ad282618 258 if(!(response & 0x80)) {
y_notsu 0:2c37ad282618 259 _cs = 1;
y_notsu 0:2c37ad282618 260 _spi.write(0xFF);
y_notsu 0:2c37ad282618 261 return response;
y_notsu 0:2c37ad282618 262 }
y_notsu 0:2c37ad282618 263 }
y_notsu 0:2c37ad282618 264 _cs = 1;
y_notsu 0:2c37ad282618 265 _spi.write(0xFF);
y_notsu 0:2c37ad282618 266 return -1; // timeout
y_notsu 0:2c37ad282618 267 }
y_notsu 0:2c37ad282618 268 int SDFileSystem::_cmdx(int cmd, int arg) {
y_notsu 0:2c37ad282618 269 _cs = 0;
y_notsu 0:2c37ad282618 270
y_notsu 0:2c37ad282618 271 // send a command
y_notsu 0:2c37ad282618 272 _spi.write(0x40 | cmd);
y_notsu 0:2c37ad282618 273 _spi.write(arg >> 24);
y_notsu 0:2c37ad282618 274 _spi.write(arg >> 16);
y_notsu 0:2c37ad282618 275 _spi.write(arg >> 8);
y_notsu 0:2c37ad282618 276 _spi.write(arg >> 0);
y_notsu 0:2c37ad282618 277 _spi.write(0x95);
y_notsu 0:2c37ad282618 278
y_notsu 0:2c37ad282618 279 // wait for the repsonse (response[7] == 0)
y_notsu 0:2c37ad282618 280 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
y_notsu 0:2c37ad282618 281 int response = _spi.write(0xFF);
y_notsu 0:2c37ad282618 282 if(!(response & 0x80)) {
y_notsu 0:2c37ad282618 283 return response;
y_notsu 0:2c37ad282618 284 }
y_notsu 0:2c37ad282618 285 }
y_notsu 0:2c37ad282618 286 _cs = 1;
y_notsu 0:2c37ad282618 287 _spi.write(0xFF);
y_notsu 0:2c37ad282618 288 return -1; // timeout
y_notsu 0:2c37ad282618 289 }
y_notsu 0:2c37ad282618 290
y_notsu 0:2c37ad282618 291
y_notsu 0:2c37ad282618 292 int SDFileSystem::_cmd58() {
y_notsu 0:2c37ad282618 293 _cs = 0;
y_notsu 0:2c37ad282618 294 int arg = 0;
y_notsu 0:2c37ad282618 295
y_notsu 0:2c37ad282618 296 // send a command
y_notsu 0:2c37ad282618 297 _spi.write(0x40 | 58);
y_notsu 0:2c37ad282618 298 _spi.write(arg >> 24);
y_notsu 0:2c37ad282618 299 _spi.write(arg >> 16);
y_notsu 0:2c37ad282618 300 _spi.write(arg >> 8);
y_notsu 0:2c37ad282618 301 _spi.write(arg >> 0);
y_notsu 0:2c37ad282618 302 _spi.write(0x95);
y_notsu 0:2c37ad282618 303
y_notsu 0:2c37ad282618 304 // wait for the repsonse (response[7] == 0)
y_notsu 0:2c37ad282618 305 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
y_notsu 0:2c37ad282618 306 int response = _spi.write(0xFF);
y_notsu 0:2c37ad282618 307 if(!(response & 0x80)) {
y_notsu 0:2c37ad282618 308 int ocr = _spi.write(0xFF) << 24;
y_notsu 0:2c37ad282618 309 ocr |= _spi.write(0xFF) << 16;
y_notsu 0:2c37ad282618 310 ocr |= _spi.write(0xFF) << 8;
y_notsu 0:2c37ad282618 311 ocr |= _spi.write(0xFF) << 0;
y_notsu 0:2c37ad282618 312 // printf("OCR = 0x%08X\n", ocr);
y_notsu 0:2c37ad282618 313 _cs = 1;
y_notsu 0:2c37ad282618 314 _spi.write(0xFF);
y_notsu 0:2c37ad282618 315 return response;
y_notsu 0:2c37ad282618 316 }
y_notsu 0:2c37ad282618 317 }
y_notsu 0:2c37ad282618 318 _cs = 1;
y_notsu 0:2c37ad282618 319 _spi.write(0xFF);
y_notsu 0:2c37ad282618 320 return -1; // timeout
y_notsu 0:2c37ad282618 321 }
y_notsu 0:2c37ad282618 322
y_notsu 0:2c37ad282618 323 int SDFileSystem::_cmd8() {
y_notsu 0:2c37ad282618 324 _cs = 0;
y_notsu 0:2c37ad282618 325
y_notsu 0:2c37ad282618 326 // send a command
y_notsu 0:2c37ad282618 327 _spi.write(0x40 | 8); // CMD8
y_notsu 0:2c37ad282618 328 _spi.write(0x00); // reserved
y_notsu 0:2c37ad282618 329 _spi.write(0x00); // reserved
y_notsu 0:2c37ad282618 330 _spi.write(0x01); // 3.3v
y_notsu 0:2c37ad282618 331 _spi.write(0xAA); // check pattern
y_notsu 0:2c37ad282618 332 _spi.write(0x87); // crc
y_notsu 0:2c37ad282618 333
y_notsu 0:2c37ad282618 334 // wait for the repsonse (response[7] == 0)
y_notsu 0:2c37ad282618 335 for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) {
y_notsu 0:2c37ad282618 336 char response[5];
y_notsu 0:2c37ad282618 337 response[0] = _spi.write(0xFF);
y_notsu 0:2c37ad282618 338 if(!(response[0] & 0x80)) {
y_notsu 0:2c37ad282618 339 for(int j=1; j<5; j++) {
y_notsu 0:2c37ad282618 340 response[i] = _spi.write(0xFF);
y_notsu 0:2c37ad282618 341 }
y_notsu 0:2c37ad282618 342 _cs = 1;
y_notsu 0:2c37ad282618 343 _spi.write(0xFF);
y_notsu 0:2c37ad282618 344 return response[0];
y_notsu 0:2c37ad282618 345 }
y_notsu 0:2c37ad282618 346 }
y_notsu 0:2c37ad282618 347 _cs = 1;
y_notsu 0:2c37ad282618 348 _spi.write(0xFF);
y_notsu 0:2c37ad282618 349 return -1; // timeout
y_notsu 0:2c37ad282618 350 }
y_notsu 0:2c37ad282618 351
y_notsu 0:2c37ad282618 352 int SDFileSystem::_read(char *buffer, int length) {
y_notsu 0:2c37ad282618 353 _cs = 0;
y_notsu 0:2c37ad282618 354
y_notsu 0:2c37ad282618 355 // read until start byte (0xFF)
y_notsu 0:2c37ad282618 356 while(_spi.write(0xFF) != 0xFE);
y_notsu 0:2c37ad282618 357
y_notsu 0:2c37ad282618 358 // read data
y_notsu 0:2c37ad282618 359 for(int i=0; i<length; i++) {
y_notsu 0:2c37ad282618 360 buffer[i] = _spi.write(0xFF);
y_notsu 0:2c37ad282618 361 }
y_notsu 0:2c37ad282618 362 _spi.write(0xFF); // checksum
y_notsu 0:2c37ad282618 363 _spi.write(0xFF);
y_notsu 0:2c37ad282618 364
y_notsu 0:2c37ad282618 365 _cs = 1;
y_notsu 0:2c37ad282618 366 _spi.write(0xFF);
y_notsu 0:2c37ad282618 367 return 0;
y_notsu 0:2c37ad282618 368 }
y_notsu 0:2c37ad282618 369
y_notsu 0:2c37ad282618 370 int SDFileSystem::_write(const char *buffer, int length) {
y_notsu 0:2c37ad282618 371 _cs = 0;
y_notsu 0:2c37ad282618 372
y_notsu 0:2c37ad282618 373 // indicate start of block
y_notsu 0:2c37ad282618 374 _spi.write(0xFE);
y_notsu 0:2c37ad282618 375
y_notsu 0:2c37ad282618 376 // write the data
y_notsu 0:2c37ad282618 377 for(int i=0; i<length; i++) {
y_notsu 0:2c37ad282618 378 _spi.write(buffer[i]);
y_notsu 0:2c37ad282618 379 }
y_notsu 0:2c37ad282618 380
y_notsu 0:2c37ad282618 381 // write the checksum
y_notsu 0:2c37ad282618 382 _spi.write(0xFF);
y_notsu 0:2c37ad282618 383 _spi.write(0xFF);
y_notsu 0:2c37ad282618 384
y_notsu 0:2c37ad282618 385 // check the repsonse token
y_notsu 0:2c37ad282618 386 if((_spi.write(0xFF) & 0x1F) != 0x05) {
y_notsu 0:2c37ad282618 387 _cs = 1;
y_notsu 0:2c37ad282618 388 _spi.write(0xFF);
y_notsu 0:2c37ad282618 389 return 1;
y_notsu 0:2c37ad282618 390 }
y_notsu 0:2c37ad282618 391
y_notsu 0:2c37ad282618 392 // wait for write to finish
y_notsu 0:2c37ad282618 393 while(_spi.write(0xFF) == 0);
y_notsu 0:2c37ad282618 394
y_notsu 0:2c37ad282618 395 _cs = 1;
y_notsu 0:2c37ad282618 396 _spi.write(0xFF);
y_notsu 0:2c37ad282618 397 return 0;
y_notsu 0:2c37ad282618 398 }
y_notsu 0:2c37ad282618 399
y_notsu 0:2c37ad282618 400 static int ext_bits(char *data, int msb, int lsb) {
y_notsu 0:2c37ad282618 401 int bits = 0;
y_notsu 0:2c37ad282618 402 int size = 1 + msb - lsb;
y_notsu 0:2c37ad282618 403 for(int i=0; i<size; i++) {
y_notsu 0:2c37ad282618 404 int position = lsb + i;
y_notsu 0:2c37ad282618 405 int byte = 15 - (position >> 3);
y_notsu 0:2c37ad282618 406 int bit = position & 0x7;
y_notsu 0:2c37ad282618 407 int value = (data[byte] >> bit) & 1;
y_notsu 0:2c37ad282618 408 bits |= value << i;
y_notsu 0:2c37ad282618 409 }
y_notsu 0:2c37ad282618 410 return bits;
y_notsu 0:2c37ad282618 411 }
y_notsu 0:2c37ad282618 412
y_notsu 0:2c37ad282618 413 int SDFileSystem::_sd_sectors() {
y_notsu 0:2c37ad282618 414
y_notsu 0:2c37ad282618 415 // CMD9, Response R2 (R1 byte + 16-byte block read)
y_notsu 0:2c37ad282618 416 if(_cmdx(9, 0) != 0) {
y_notsu 0:2c37ad282618 417 fprintf(stderr, "Didn't get a response from the disk\n");
y_notsu 0:2c37ad282618 418 return 0;
y_notsu 0:2c37ad282618 419 }
y_notsu 0:2c37ad282618 420
y_notsu 0:2c37ad282618 421 char csd[16];
y_notsu 0:2c37ad282618 422 if(_read(csd, 16) != 0) {
y_notsu 0:2c37ad282618 423 fprintf(stderr, "Couldn't read csd response from disk\n");
y_notsu 0:2c37ad282618 424 return 0;
y_notsu 0:2c37ad282618 425 }
y_notsu 0:2c37ad282618 426
y_notsu 0:2c37ad282618 427 // csd_structure : csd[127:126]
y_notsu 0:2c37ad282618 428 // c_size : csd[73:62]
y_notsu 0:2c37ad282618 429 // c_size_mult : csd[49:47]
y_notsu 0:2c37ad282618 430 // read_bl_len : csd[83:80] - the *maximum* read block length
y_notsu 0:2c37ad282618 431
y_notsu 0:2c37ad282618 432 int csd_structure = ext_bits(csd, 127, 126);
y_notsu 0:2c37ad282618 433 int c_size = ext_bits(csd, 73, 62);
y_notsu 0:2c37ad282618 434 int c_size_mult = ext_bits(csd, 49, 47);
y_notsu 0:2c37ad282618 435 int read_bl_len = ext_bits(csd, 83, 80);
y_notsu 0:2c37ad282618 436
y_notsu 0:2c37ad282618 437 // printf("CSD_STRUCT = %d\n", csd_structure);
y_notsu 0:2c37ad282618 438
y_notsu 0:2c37ad282618 439 if(csd_structure != 0) {
y_notsu 0:2c37ad282618 440 fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n");
y_notsu 0:2c37ad282618 441 return 0;
y_notsu 0:2c37ad282618 442 }
y_notsu 0:2c37ad282618 443
y_notsu 0:2c37ad282618 444 // memory capacity = BLOCKNR * BLOCK_LEN
y_notsu 0:2c37ad282618 445 // where
y_notsu 0:2c37ad282618 446 // BLOCKNR = (C_SIZE+1) * MULT
y_notsu 0:2c37ad282618 447 // MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8)
y_notsu 0:2c37ad282618 448 // BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12)
y_notsu 0:2c37ad282618 449
y_notsu 0:2c37ad282618 450 int block_len = 1 << read_bl_len;
y_notsu 0:2c37ad282618 451 int mult = 1 << (c_size_mult + 2);
y_notsu 0:2c37ad282618 452 int blocknr = (c_size + 1) * mult;
y_notsu 0:2c37ad282618 453 int capacity = blocknr * block_len;
y_notsu 0:2c37ad282618 454
y_notsu 0:2c37ad282618 455 int blocks = capacity / 512;
y_notsu 0:2c37ad282618 456
y_notsu 0:2c37ad282618 457 return blocks;
y_notsu 0:2c37ad282618 458 }