Tyler Weaver / SDHC_FileSystem

SDHCFileSystem in a library. Requires FatFileSystem

Dependents:   sdhc_speed_test ZY_FGD1442701V1_BusOut_SDHC frdm_gpio SDcard

SDHCFileSystem.cpp@0:b553aa902f90, 2012-10-15 (annotated)

Committer:
tylerjw
Date:
Mon Oct 15 18:35:58 2012 +0000
Revision:
0:b553aa902f90
SDHC FileSystem placed in a library.; ; Requires FatFileSystem

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tylerjw 0:b553aa902f90 1 /* mbed SDFileSystem Library, for providing file access to SD cards
tylerjw 0:b553aa902f90 2 * Copyright (c) 2008-2010, sford
tylerjw 0:b553aa902f90 3 *
tylerjw 0:b553aa902f90 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
tylerjw 0:b553aa902f90 5 * of this software and associated documentation files (the "Software"), to deal
tylerjw 0:b553aa902f90 6 * in the Software without restriction, including without limitation the rights
tylerjw 0:b553aa902f90 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
tylerjw 0:b553aa902f90 8 * copies of the Software, and to permit persons to whom the Software is
tylerjw 0:b553aa902f90 9 * furnished to do so, subject to the following conditions:
tylerjw 0:b553aa902f90 10 *
tylerjw 0:b553aa902f90 11 * The above copyright notice and this permission notice shall be included in
tylerjw 0:b553aa902f90 12 * all copies or substantial portions of the Software.
tylerjw 0:b553aa902f90 13 *
tylerjw 0:b553aa902f90 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
tylerjw 0:b553aa902f90 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
tylerjw 0:b553aa902f90 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
tylerjw 0:b553aa902f90 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
tylerjw 0:b553aa902f90 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
tylerjw 0:b553aa902f90 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
tylerjw 0:b553aa902f90 20 * THE SOFTWARE.
tylerjw 0:b553aa902f90 21 */
tylerjw 0:b553aa902f90 22
tylerjw 0:b553aa902f90 23 /* Introduction
tylerjw 0:b553aa902f90 24 * ------------
tylerjw 0:b553aa902f90 25 * SD and MMC cards support a number of interfaces, but common to them all
tylerjw 0:b553aa902f90 26 * is one based on SPI. This is the one I'm implmenting because it means
tylerjw 0:b553aa902f90 27 * it is much more portable even though not so performant, and we already
tylerjw 0:b553aa902f90 28 * have the mbed SPI Interface!
tylerjw 0:b553aa902f90 29 *
tylerjw 0:b553aa902f90 30 * The main reference I'm using is Chapter 7, "SPI Mode" of:
tylerjw 0:b553aa902f90 31 * http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
tylerjw 0:b553aa902f90 32 *
tylerjw 0:b553aa902f90 33 * SPI Startup
tylerjw 0:b553aa902f90 34 * -----------
tylerjw 0:b553aa902f90 35 * The SD card powers up in SD mode. The SPI interface mode is selected by
tylerjw 0:b553aa902f90 36 * asserting CS low and sending the reset command (CMD0). The card will
tylerjw 0:b553aa902f90 37 * respond with a (R1) response.
tylerjw 0:b553aa902f90 38 *
tylerjw 0:b553aa902f90 39 * CMD8 is optionally sent to determine the voltage range supported, and
tylerjw 0:b553aa902f90 40 * indirectly determine whether it is a version 1.x SD/non-SD card or
tylerjw 0:b553aa902f90 41 * version 2.x. I'll just ignore this for now.
tylerjw 0:b553aa902f90 42 *
tylerjw 0:b553aa902f90 43 * ACMD41 is repeatedly issued to initialise the card, until "in idle"
tylerjw 0:b553aa902f90 44 * (bit 0) of the R1 response goes to '0', indicating it is initialised.
tylerjw 0:b553aa902f90 45 *
tylerjw 0:b553aa902f90 46 * You should also indicate whether the host supports High Capicity cards,
tylerjw 0:b553aa902f90 47 * and check whether the card is high capacity - i'll also ignore this
tylerjw 0:b553aa902f90 48 *
tylerjw 0:b553aa902f90 49 * SPI Protocol
tylerjw 0:b553aa902f90 50 * ------------
tylerjw 0:b553aa902f90 51 * The SD SPI protocol is based on transactions made up of 8-bit words, with
tylerjw 0:b553aa902f90 52 * the host starting every bus transaction by asserting the CS signal low. The
tylerjw 0:b553aa902f90 53 * card always responds to commands, data blocks and errors.
tylerjw 0:b553aa902f90 54 *
tylerjw 0:b553aa902f90 55 * The protocol supports a CRC, but by default it is off (except for the
tylerjw 0:b553aa902f90 56 * first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
tylerjw 0:b553aa902f90 57 * I'll leave the CRC off I think!
tylerjw 0:b553aa902f90 58 *
tylerjw 0:b553aa902f90 59 * Standard capacity cards have variable data block sizes, whereas High
tylerjw 0:b553aa902f90 60 * Capacity cards fix the size of data block to 512 bytes. I'll therefore
tylerjw 0:b553aa902f90 61 * just always use the Standard Capacity cards with a block size of 512 bytes.
tylerjw 0:b553aa902f90 62 * This is set with CMD16.
tylerjw 0:b553aa902f90 63 *
tylerjw 0:b553aa902f90 64 * You can read and write single blocks (CMD17, CMD25) or multiple blocks
tylerjw 0:b553aa902f90 65 * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
tylerjw 0:b553aa902f90 66 * the card gets a read command, it responds with a response token, and then
tylerjw 0:b553aa902f90 67 * a data token or an error.
tylerjw 0:b553aa902f90 68 *
tylerjw 0:b553aa902f90 69 * SPI Command Format
tylerjw 0:b553aa902f90 70 * ------------------
tylerjw 0:b553aa902f90 71 * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
tylerjw 0:b553aa902f90 72 *
tylerjw 0:b553aa902f90 73 * +---------------+------------+------------+-----------+----------+--------------+
tylerjw 0:b553aa902f90 74 * | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 |
tylerjw 0:b553aa902f90 75 * +---------------+------------+------------+-----------+----------+--------------+
tylerjw 0:b553aa902f90 76 *
tylerjw 0:b553aa902f90 77 * As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
tylerjw 0:b553aa902f90 78 *
tylerjw 0:b553aa902f90 79 * All Application Specific commands shall be preceded with APP_CMD (CMD55).
tylerjw 0:b553aa902f90 80 *
tylerjw 0:b553aa902f90 81 * SPI Response Format
tylerjw 0:b553aa902f90 82 * -------------------
tylerjw 0:b553aa902f90 83 * The main response format (R1) is a status byte (normally zero). Key flags:
tylerjw 0:b553aa902f90 84 * idle - 1 if the card is in an idle state/initialising
tylerjw 0:b553aa902f90 85 * cmd - 1 if an illegal command code was detected
tylerjw 0:b553aa902f90 86 *
tylerjw 0:b553aa902f90 87 * +-------------------------------------------------+
tylerjw 0:b553aa902f90 88 * R1 | 0 | arg | addr | seq | crc | cmd | erase | idle |
tylerjw 0:b553aa902f90 89 * +-------------------------------------------------+
tylerjw 0:b553aa902f90 90 *
tylerjw 0:b553aa902f90 91 * R1b is the same, except it is followed by a busy signal (zeros) until
tylerjw 0:b553aa902f90 92 * the first non-zero byte when it is ready again.
tylerjw 0:b553aa902f90 93 *
tylerjw 0:b553aa902f90 94 * Data Response Token
tylerjw 0:b553aa902f90 95 * -------------------
tylerjw 0:b553aa902f90 96 * Every data block written to the card is acknowledged by a byte
tylerjw 0:b553aa902f90 97 * response token
tylerjw 0:b553aa902f90 98 *
tylerjw 0:b553aa902f90 99 * +----------------------+
tylerjw 0:b553aa902f90 100 * | xxx | 0 | status | 1 |
tylerjw 0:b553aa902f90 101 * +----------------------+
tylerjw 0:b553aa902f90 102 * 010 - OK!
tylerjw 0:b553aa902f90 103 * 101 - CRC Error
tylerjw 0:b553aa902f90 104 * 110 - Write Error
tylerjw 0:b553aa902f90 105 *
tylerjw 0:b553aa902f90 106 * Single Block Read and Write
tylerjw 0:b553aa902f90 107 * ---------------------------
tylerjw 0:b553aa902f90 108 *
tylerjw 0:b553aa902f90 109 * Block transfers have a byte header, followed by the data, followed
tylerjw 0:b553aa902f90 110 * by a 16-bit CRC. In our case, the data will always be 512 bytes.
tylerjw 0:b553aa902f90 111 *
tylerjw 0:b553aa902f90 112 * +------+---------+---------+- - - -+---------+-----------+----------+
tylerjw 0:b553aa902f90 113 * | 0xFE | data[0] | data[1] | | data[n] | crc[15:8] | crc[7:0] |
tylerjw 0:b553aa902f90 114 * +------+---------+---------+- - - -+---------+-----------+----------+
tylerjw 0:b553aa902f90 115 */
tylerjw 0:b553aa902f90 116
tylerjw 0:b553aa902f90 117 /*
tylerjw 0:b553aa902f90 118 * Comment: Changes for SDHC support till 32GB
tylerjw 0:b553aa902f90 119 * Name: KB
tylerjw 0:b553aa902f90 120 * Date: 07/24/2010
tylerjw 0:b553aa902f90 121 * Release: 0.1
tylerjw 0:b553aa902f90 122 */
tylerjw 0:b553aa902f90 123
tylerjw 0:b553aa902f90 124 #include "SDHCFileSystem.h"
tylerjw 0:b553aa902f90 125
tylerjw 0:b553aa902f90 126 #define DEBUG
tylerjw 0:b553aa902f90 127 #define SD_COMMAND_TIMEOUT 5000
tylerjw 0:b553aa902f90 128
tylerjw 0:b553aa902f90 129
tylerjw 0:b553aa902f90 130 SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
tylerjw 0:b553aa902f90 131 FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) {
tylerjw 0:b553aa902f90 132 _cs = 1;
tylerjw 0:b553aa902f90 133 }
tylerjw 0:b553aa902f90 134
tylerjw 0:b553aa902f90 135 #define R1_IDLE_STATE (1 << 0)
tylerjw 0:b553aa902f90 136 #define R1_ERASE_RESET (1 << 1)
tylerjw 0:b553aa902f90 137 #define R1_ILLEGAL_COMMAND (1 << 2)
tylerjw 0:b553aa902f90 138 #define R1_COM_CRC_ERROR (1 << 3)
tylerjw 0:b553aa902f90 139 #define R1_ERASE_SEQUENCE_ERROR (1 << 4)
tylerjw 0:b553aa902f90 140 #define R1_ADDRESS_ERROR (1 << 5)
tylerjw 0:b553aa902f90 141 #define R1_PARAMETER_ERROR (1 << 6)
tylerjw 0:b553aa902f90 142
tylerjw 0:b553aa902f90 143 // Types
tylerjw 0:b553aa902f90 144 // - v1.x Standard Capacity
tylerjw 0:b553aa902f90 145 // - v2.x Standard Capacity
tylerjw 0:b553aa902f90 146 // - v2.x High Capacity
tylerjw 0:b553aa902f90 147 // - Not recognised as an SD Card
tylerjw 0:b553aa902f90 148
tylerjw 0:b553aa902f90 149 #define SDCARD_FAIL 0
tylerjw 0:b553aa902f90 150 #define SDCARD_V1 1
tylerjw 0:b553aa902f90 151 #define SDCARD_V2 2
tylerjw 0:b553aa902f90 152 #define SDCARD_V2HC 3
tylerjw 0:b553aa902f90 153
tylerjw 0:b553aa902f90 154 int SDFileSystem::initialise_card() {
tylerjw 0:b553aa902f90 155 // Set to 100kHz for initialisation, and clock card with cs = 1
tylerjw 0:b553aa902f90 156 _spi.frequency(100000);
tylerjw 0:b553aa902f90 157 _cs = 1;
tylerjw 0:b553aa902f90 158 for(int i=0; i<16; i++) {
tylerjw 0:b553aa902f90 159 _spi.write(0xFF);
tylerjw 0:b553aa902f90 160 }
tylerjw 0:b553aa902f90 161
tylerjw 0:b553aa902f90 162 // send CMD0, should return with all zeros except IDLE STATE set (bit 0)
tylerjw 0:b553aa902f90 163 if(_cmd(0, 0) != R1_IDLE_STATE) {
tylerjw 0:b553aa902f90 164 fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n");
tylerjw 0:b553aa902f90 165 return SDCARD_FAIL;
tylerjw 0:b553aa902f90 166 }
tylerjw 0:b553aa902f90 167
tylerjw 0:b553aa902f90 168 // send CMD8 to determine whther it is ver 2.x
tylerjw 0:b553aa902f90 169 int r = _cmd8();
tylerjw 0:b553aa902f90 170 if(r == R1_IDLE_STATE) {
tylerjw 0:b553aa902f90 171 return initialise_card_v2();
tylerjw 0:b553aa902f90 172 } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
tylerjw 0:b553aa902f90 173 return initialise_card_v1();
tylerjw 0:b553aa902f90 174 } else {
tylerjw 0:b553aa902f90 175 fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n");
tylerjw 0:b553aa902f90 176 return SDCARD_FAIL;
tylerjw 0:b553aa902f90 177 }
tylerjw 0:b553aa902f90 178 }
tylerjw 0:b553aa902f90 179
tylerjw 0:b553aa902f90 180 int SDFileSystem::initialise_card_v1() {
tylerjw 0:b553aa902f90 181 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
tylerjw 0:b553aa902f90 182 _cmd(55, 0);
tylerjw 0:b553aa902f90 183 if(_cmd(41, 0) == 0) {
tylerjw 0:b553aa902f90 184 cdv = 512;
tylerjw 0:b553aa902f90 185 #ifdef DEBUG
tylerjw 0:b553aa902f90 186 printf("\n\rInit: SEDCARD_V1\n\r");
tylerjw 0:b553aa902f90 187 #endif
tylerjw 0:b553aa902f90 188 return SDCARD_V1;
tylerjw 0:b553aa902f90 189 }
tylerjw 0:b553aa902f90 190 }
tylerjw 0:b553aa902f90 191
tylerjw 0:b553aa902f90 192 fprintf(stderr, "Timeout waiting for v1.x card\n");
tylerjw 0:b553aa902f90 193 return SDCARD_FAIL;
tylerjw 0:b553aa902f90 194 }
tylerjw 0:b553aa902f90 195
tylerjw 0:b553aa902f90 196 int SDFileSystem::initialise_card_v2() {
tylerjw 0:b553aa902f90 197
tylerjw 0:b553aa902f90 198 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
tylerjw 0:b553aa902f90 199 wait_ms(50);
tylerjw 0:b553aa902f90 200 _cmd58();
tylerjw 0:b553aa902f90 201 _cmd(55, 0);
tylerjw 0:b553aa902f90 202 if(_cmd(41, 0x40000000) == 0) {
tylerjw 0:b553aa902f90 203 _cmd58();
tylerjw 0:b553aa902f90 204 #ifdef DEBUG
tylerjw 0:b553aa902f90 205 printf("\n\rInit: SDCARD_V2\n\r");
tylerjw 0:b553aa902f90 206 #endif
tylerjw 0:b553aa902f90 207 cdv = 1;
tylerjw 0:b553aa902f90 208 return SDCARD_V2;
tylerjw 0:b553aa902f90 209 }
tylerjw 0:b553aa902f90 210 }
tylerjw 0:b553aa902f90 211
tylerjw 0:b553aa902f90 212 fprintf(stderr, "Timeout waiting for v2.x card\n");
tylerjw 0:b553aa902f90 213 return SDCARD_FAIL;
tylerjw 0:b553aa902f90 214 }
tylerjw 0:b553aa902f90 215
tylerjw 0:b553aa902f90 216 int SDFileSystem::disk_initialize() {
tylerjw 0:b553aa902f90 217
tylerjw 0:b553aa902f90 218 int i = initialise_card();
tylerjw 0:b553aa902f90 219 #ifdef DEBUG
tylerjw 0:b553aa902f90 220 printf("init card = %d\n", i);
tylerjw 0:b553aa902f90 221 #endif
tylerjw 0:b553aa902f90 222 _sectors = _sd_sectors();
tylerjw 0:b553aa902f90 223
tylerjw 0:b553aa902f90 224 // Set block length to 512 (CMD16)
tylerjw 0:b553aa902f90 225 if(_cmd(16, 512) != 0) {
tylerjw 0:b553aa902f90 226 fprintf(stderr, "Set 512-byte block timed out\n");
tylerjw 0:b553aa902f90 227 return 1;
tylerjw 0:b553aa902f90 228 }
tylerjw 0:b553aa902f90 229
tylerjw 0:b553aa902f90 230 _spi.frequency(1000000); // Set to 1MHz for data transfer
tylerjw 0:b553aa902f90 231 return 0;
tylerjw 0:b553aa902f90 232 }
tylerjw 0:b553aa902f90 233
tylerjw 0:b553aa902f90 234 int SDFileSystem::disk_write(const char *buffer, int block_number) {
tylerjw 0:b553aa902f90 235 // set write address for single block (CMD24)
tylerjw 0:b553aa902f90 236 if(_cmd(24, block_number * cdv) != 0) {
tylerjw 0:b553aa902f90 237 return 1;
tylerjw 0:b553aa902f90 238 }
tylerjw 0:b553aa902f90 239
tylerjw 0:b553aa902f90 240 // send the data block
tylerjw 0:b553aa902f90 241 _write(buffer, 512);
tylerjw 0:b553aa902f90 242 return 0;
tylerjw 0:b553aa902f90 243 }
tylerjw 0:b553aa902f90 244
tylerjw 0:b553aa902f90 245 int SDFileSystem::disk_read(char *buffer, int block_number) {
tylerjw 0:b553aa902f90 246 // set read address for single block (CMD17)
tylerjw 0:b553aa902f90 247 if(_cmd(17, block_number * cdv) != 0) {
tylerjw 0:b553aa902f90 248 return 1;
tylerjw 0:b553aa902f90 249 }
tylerjw 0:b553aa902f90 250
tylerjw 0:b553aa902f90 251 // receive the data
tylerjw 0:b553aa902f90 252 _read(buffer, 512);
tylerjw 0:b553aa902f90 253 return 0;
tylerjw 0:b553aa902f90 254 }
tylerjw 0:b553aa902f90 255
tylerjw 0:b553aa902f90 256 int SDFileSystem::disk_status() { return 0; }
tylerjw 0:b553aa902f90 257 int SDFileSystem::disk_sync() { return 0; }
tylerjw 0:b553aa902f90 258 int SDFileSystem::disk_sectors() { return _sectors; }
tylerjw 0:b553aa902f90 259
tylerjw 0:b553aa902f90 260 // PRIVATE FUNCTIONS
tylerjw 0:b553aa902f90 261
tylerjw 0:b553aa902f90 262 int SDFileSystem::_cmd(int cmd, int arg) {
tylerjw 0:b553aa902f90 263 _cs = 0;
tylerjw 0:b553aa902f90 264
tylerjw 0:b553aa902f90 265 // send a command
tylerjw 0:b553aa902f90 266 _spi.write(0x40 | cmd);
tylerjw 0:b553aa902f90 267 _spi.write(arg >> 24);
tylerjw 0:b553aa902f90 268 _spi.write(arg >> 16);
tylerjw 0:b553aa902f90 269 _spi.write(arg >> 8);
tylerjw 0:b553aa902f90 270 _spi.write(arg >> 0);
tylerjw 0:b553aa902f90 271 _spi.write(0x95);
tylerjw 0:b553aa902f90 272
tylerjw 0:b553aa902f90 273 // wait for the repsonse (response[7] == 0)
tylerjw 0:b553aa902f90 274 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
tylerjw 0:b553aa902f90 275 int response = _spi.write(0xFF);
tylerjw 0:b553aa902f90 276 if(!(response & 0x80)) {
tylerjw 0:b553aa902f90 277 _cs = 1;
tylerjw 0:b553aa902f90 278 _spi.write(0xFF);
tylerjw 0:b553aa902f90 279 return response;
tylerjw 0:b553aa902f90 280 }
tylerjw 0:b553aa902f90 281 }
tylerjw 0:b553aa902f90 282 _cs = 1;
tylerjw 0:b553aa902f90 283 _spi.write(0xFF);
tylerjw 0:b553aa902f90 284 return -1; // timeout
tylerjw 0:b553aa902f90 285 }
tylerjw 0:b553aa902f90 286 int SDFileSystem::_cmdx(int cmd, int arg) {
tylerjw 0:b553aa902f90 287 _cs = 0;
tylerjw 0:b553aa902f90 288
tylerjw 0:b553aa902f90 289 // send a command
tylerjw 0:b553aa902f90 290 _spi.write(0x40 | cmd);
tylerjw 0:b553aa902f90 291 _spi.write(arg >> 24);
tylerjw 0:b553aa902f90 292 _spi.write(arg >> 16);
tylerjw 0:b553aa902f90 293 _spi.write(arg >> 8);
tylerjw 0:b553aa902f90 294 _spi.write(arg >> 0);
tylerjw 0:b553aa902f90 295 _spi.write(0x95);
tylerjw 0:b553aa902f90 296
tylerjw 0:b553aa902f90 297 // wait for the repsonse (response[7] == 0)
tylerjw 0:b553aa902f90 298 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
tylerjw 0:b553aa902f90 299 int response = _spi.write(0xFF);
tylerjw 0:b553aa902f90 300 if(!(response & 0x80)) {
tylerjw 0:b553aa902f90 301 return response;
tylerjw 0:b553aa902f90 302 }
tylerjw 0:b553aa902f90 303 }
tylerjw 0:b553aa902f90 304 _cs = 1;
tylerjw 0:b553aa902f90 305 _spi.write(0xFF);
tylerjw 0:b553aa902f90 306 return -1; // timeout
tylerjw 0:b553aa902f90 307 }
tylerjw 0:b553aa902f90 308
tylerjw 0:b553aa902f90 309
tylerjw 0:b553aa902f90 310 int SDFileSystem::_cmd58() {
tylerjw 0:b553aa902f90 311 _cs = 0;
tylerjw 0:b553aa902f90 312 int arg = 0;
tylerjw 0:b553aa902f90 313
tylerjw 0:b553aa902f90 314 // send a command
tylerjw 0:b553aa902f90 315 _spi.write(0x40 | 58);
tylerjw 0:b553aa902f90 316 _spi.write(arg >> 24);
tylerjw 0:b553aa902f90 317 _spi.write(arg >> 16);
tylerjw 0:b553aa902f90 318 _spi.write(arg >> 8);
tylerjw 0:b553aa902f90 319 _spi.write(arg >> 0);
tylerjw 0:b553aa902f90 320 _spi.write(0x95);
tylerjw 0:b553aa902f90 321
tylerjw 0:b553aa902f90 322 // wait for the repsonse (response[7] == 0)
tylerjw 0:b553aa902f90 323 for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
tylerjw 0:b553aa902f90 324 int response = _spi.write(0xFF);
tylerjw 0:b553aa902f90 325 if(!(response & 0x80)) {
tylerjw 0:b553aa902f90 326 int ocr = _spi.write(0xFF) << 24;
tylerjw 0:b553aa902f90 327 ocr |= _spi.write(0xFF) << 16;
tylerjw 0:b553aa902f90 328 ocr |= _spi.write(0xFF) << 8;
tylerjw 0:b553aa902f90 329 ocr |= _spi.write(0xFF) << 0;
tylerjw 0:b553aa902f90 330 // printf("OCR = 0x%08X\n", ocr);
tylerjw 0:b553aa902f90 331 _cs = 1;
tylerjw 0:b553aa902f90 332 _spi.write(0xFF);
tylerjw 0:b553aa902f90 333 return response;
tylerjw 0:b553aa902f90 334 }
tylerjw 0:b553aa902f90 335 }
tylerjw 0:b553aa902f90 336 _cs = 1;
tylerjw 0:b553aa902f90 337 _spi.write(0xFF);
tylerjw 0:b553aa902f90 338 return -1; // timeout
tylerjw 0:b553aa902f90 339 }
tylerjw 0:b553aa902f90 340
tylerjw 0:b553aa902f90 341 int SDFileSystem::_cmd8() {
tylerjw 0:b553aa902f90 342 _cs = 0;
tylerjw 0:b553aa902f90 343
tylerjw 0:b553aa902f90 344 // send a command
tylerjw 0:b553aa902f90 345 _spi.write(0x40 | 8); // CMD8
tylerjw 0:b553aa902f90 346 _spi.write(0x00); // reserved
tylerjw 0:b553aa902f90 347 _spi.write(0x00); // reserved
tylerjw 0:b553aa902f90 348 _spi.write(0x01); // 3.3v
tylerjw 0:b553aa902f90 349 _spi.write(0xAA); // check pattern
tylerjw 0:b553aa902f90 350 _spi.write(0x87); // crc
tylerjw 0:b553aa902f90 351
tylerjw 0:b553aa902f90 352 // wait for the repsonse (response[7] == 0)
tylerjw 0:b553aa902f90 353 for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) {
tylerjw 0:b553aa902f90 354 char response[5];
tylerjw 0:b553aa902f90 355 response[0] = _spi.write(0xFF);
tylerjw 0:b553aa902f90 356 if(!(response[0] & 0x80)) {
tylerjw 0:b553aa902f90 357 for(int j=1; j<5; j++) {
tylerjw 0:b553aa902f90 358 response[i] = _spi.write(0xFF);
tylerjw 0:b553aa902f90 359 }
tylerjw 0:b553aa902f90 360 _cs = 1;
tylerjw 0:b553aa902f90 361 _spi.write(0xFF);
tylerjw 0:b553aa902f90 362 return response[0];
tylerjw 0:b553aa902f90 363 }
tylerjw 0:b553aa902f90 364 }
tylerjw 0:b553aa902f90 365 _cs = 1;
tylerjw 0:b553aa902f90 366 _spi.write(0xFF);
tylerjw 0:b553aa902f90 367 return -1; // timeout
tylerjw 0:b553aa902f90 368 }
tylerjw 0:b553aa902f90 369
tylerjw 0:b553aa902f90 370 int SDFileSystem::_read(char *buffer, int length) {
tylerjw 0:b553aa902f90 371 _cs = 0;
tylerjw 0:b553aa902f90 372
tylerjw 0:b553aa902f90 373 // read until start byte (0xFF)
tylerjw 0:b553aa902f90 374 while(_spi.write(0xFF) != 0xFE);
tylerjw 0:b553aa902f90 375
tylerjw 0:b553aa902f90 376 // read data
tylerjw 0:b553aa902f90 377 for(int i=0; i<length; i++) {
tylerjw 0:b553aa902f90 378 buffer[i] = _spi.write(0xFF);
tylerjw 0:b553aa902f90 379 }
tylerjw 0:b553aa902f90 380 _spi.write(0xFF); // checksum
tylerjw 0:b553aa902f90 381 _spi.write(0xFF);
tylerjw 0:b553aa902f90 382
tylerjw 0:b553aa902f90 383 _cs = 1;
tylerjw 0:b553aa902f90 384 _spi.write(0xFF);
tylerjw 0:b553aa902f90 385 return 0;
tylerjw 0:b553aa902f90 386 }
tylerjw 0:b553aa902f90 387
tylerjw 0:b553aa902f90 388 int SDFileSystem::_write(const char *buffer, int length) {
tylerjw 0:b553aa902f90 389 _cs = 0;
tylerjw 0:b553aa902f90 390
tylerjw 0:b553aa902f90 391 // indicate start of block
tylerjw 0:b553aa902f90 392 _spi.write(0xFE);
tylerjw 0:b553aa902f90 393
tylerjw 0:b553aa902f90 394 // write the data
tylerjw 0:b553aa902f90 395 for(int i=0; i<length; i++) {
tylerjw 0:b553aa902f90 396 _spi.write(buffer[i]);
tylerjw 0:b553aa902f90 397 }
tylerjw 0:b553aa902f90 398
tylerjw 0:b553aa902f90 399 // write the checksum
tylerjw 0:b553aa902f90 400 _spi.write(0xFF);
tylerjw 0:b553aa902f90 401 _spi.write(0xFF);
tylerjw 0:b553aa902f90 402
tylerjw 0:b553aa902f90 403 // check the repsonse token
tylerjw 0:b553aa902f90 404 if((_spi.write(0xFF) & 0x1F) != 0x05) {
tylerjw 0:b553aa902f90 405 _cs = 1;
tylerjw 0:b553aa902f90 406 _spi.write(0xFF);
tylerjw 0:b553aa902f90 407 return 1;
tylerjw 0:b553aa902f90 408 }
tylerjw 0:b553aa902f90 409
tylerjw 0:b553aa902f90 410 // wait for write to finish
tylerjw 0:b553aa902f90 411 while(_spi.write(0xFF) == 0);
tylerjw 0:b553aa902f90 412
tylerjw 0:b553aa902f90 413 _cs = 1;
tylerjw 0:b553aa902f90 414 _spi.write(0xFF);
tylerjw 0:b553aa902f90 415 return 0;
tylerjw 0:b553aa902f90 416 }
tylerjw 0:b553aa902f90 417
tylerjw 0:b553aa902f90 418 static int ext_bits(char *data, int msb, int lsb) {
tylerjw 0:b553aa902f90 419 int bits = 0;
tylerjw 0:b553aa902f90 420 int size = 1 + msb - lsb;
tylerjw 0:b553aa902f90 421 for(int i=0; i<size; i++) {
tylerjw 0:b553aa902f90 422 int position = lsb + i;
tylerjw 0:b553aa902f90 423 int byte = 15 - (position >> 3);
tylerjw 0:b553aa902f90 424 int bit = position & 0x7;
tylerjw 0:b553aa902f90 425 int value = (data[byte] >> bit) & 1;
tylerjw 0:b553aa902f90 426 bits |= value << i;
tylerjw 0:b553aa902f90 427 }
tylerjw 0:b553aa902f90 428 return bits;
tylerjw 0:b553aa902f90 429 }
tylerjw 0:b553aa902f90 430
tylerjw 0:b553aa902f90 431 int SDFileSystem::_sd_sectors() {
tylerjw 0:b553aa902f90 432
tylerjw 0:b553aa902f90 433 int c_size, c_size_mult, read_bl_len;
tylerjw 0:b553aa902f90 434 int block_len, mult, blocknr, capacity;
tylerjw 0:b553aa902f90 435 int blocks, hc_c_size;
tylerjw 0:b553aa902f90 436 uint64_t hc_capacity;
tylerjw 0:b553aa902f90 437
tylerjw 0:b553aa902f90 438 // CMD9, Response R2 (R1 byte + 16-byte block read)
tylerjw 0:b553aa902f90 439 if(_cmdx(9, 0) != 0) {
tylerjw 0:b553aa902f90 440 fprintf(stderr, "Didn't get a response from the disk\n");
tylerjw 0:b553aa902f90 441 return 0;
tylerjw 0:b553aa902f90 442 }
tylerjw 0:b553aa902f90 443
tylerjw 0:b553aa902f90 444 char csd[16];
tylerjw 0:b553aa902f90 445 if(_read(csd, 16) != 0) {
tylerjw 0:b553aa902f90 446 fprintf(stderr, "Couldn't read csd response from disk\n");
tylerjw 0:b553aa902f90 447 return 0;
tylerjw 0:b553aa902f90 448 }
tylerjw 0:b553aa902f90 449
tylerjw 0:b553aa902f90 450 // csd_structure : csd[127:126]
tylerjw 0:b553aa902f90 451 // c_size : csd[73:62]
tylerjw 0:b553aa902f90 452 // c_size_mult : csd[49:47]
tylerjw 0:b553aa902f90 453 // read_bl_len : csd[83:80] - the *maximum* read block length
tylerjw 0:b553aa902f90 454
tylerjw 0:b553aa902f90 455 int csd_structure = ext_bits(csd, 127, 126);
tylerjw 0:b553aa902f90 456
tylerjw 0:b553aa902f90 457 #ifdef DEBUG
tylerjw 0:b553aa902f90 458 printf("\n\rCSD_STRUCT = %d\n", csd_structure);
tylerjw 0:b553aa902f90 459 #endif
tylerjw 0:b553aa902f90 460
tylerjw 0:b553aa902f90 461 switch (csd_structure){
tylerjw 0:b553aa902f90 462 case 0:
tylerjw 0:b553aa902f90 463 cdv = 512;
tylerjw 0:b553aa902f90 464 c_size = ext_bits(csd, 73, 62);
tylerjw 0:b553aa902f90 465 c_size_mult = ext_bits(csd, 49, 47);
tylerjw 0:b553aa902f90 466 read_bl_len = ext_bits(csd, 83, 80);
tylerjw 0:b553aa902f90 467
tylerjw 0:b553aa902f90 468 block_len = 1 << read_bl_len;
tylerjw 0:b553aa902f90 469 mult = 1 << (c_size_mult + 2);
tylerjw 0:b553aa902f90 470 blocknr = (c_size + 1) * mult;
tylerjw 0:b553aa902f90 471 capacity = blocknr * block_len;
tylerjw 0:b553aa902f90 472 blocks = capacity / 512;
tylerjw 0:b553aa902f90 473 #ifdef DEBUG
tylerjw 0:b553aa902f90 474 printf("\n\rSDCard\n\rc_size: %.4X \n\rcapacity: %.ld \n\rsectors: %d\n\r", c_size, capacity, blocks);
tylerjw 0:b553aa902f90 475 #endif
tylerjw 0:b553aa902f90 476 break;
tylerjw 0:b553aa902f90 477
tylerjw 0:b553aa902f90 478 case 1:
tylerjw 0:b553aa902f90 479 cdv = 1;
tylerjw 0:b553aa902f90 480 hc_c_size = ext_bits(csd, 63, 48);
tylerjw 0:b553aa902f90 481 int hc_read_bl_len = ext_bits(csd, 83, 80);
tylerjw 0:b553aa902f90 482 hc_capacity = hc_c_size+1;
tylerjw 0:b553aa902f90 483 blocks = (hc_c_size+1)*1024;
tylerjw 0:b553aa902f90 484 #ifdef DEBUG
tylerjw 0:b553aa902f90 485 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);
tylerjw 0:b553aa902f90 486 #endif
tylerjw 0:b553aa902f90 487 break;
tylerjw 0:b553aa902f90 488
tylerjw 0:b553aa902f90 489 default:
tylerjw 0:b553aa902f90 490 fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n");
tylerjw 0:b553aa902f90 491 return 0;
tylerjw 0:b553aa902f90 492 break;
tylerjw 0:b553aa902f90 493 };
tylerjw 0:b553aa902f90 494 return blocks;
tylerjw 0:b553aa902f90 495 }