tmk_core/tool/mbed/mbed-sdk/libraries/fs/sd/SDFileSystem.cpp

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2006-2012 ARM Limited
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  20  * SOFTWARE.
  21  */
  22 /* Introduction
  23  * ------------
  24  * SD and MMC cards support a number of interfaces, but common to them all
  25  * is one based on SPI. This is the one I'm implmenting because it means
  26  * it is much more portable even though not so performant, and we already
  27  * have the mbed SPI Interface!
  28  *
  29  * The main reference I'm using is Chapter 7, "SPI Mode" of:
  30  *  http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
  31  *
  32  * SPI Startup
  33  * -----------
  34  * The SD card powers up in SD mode. The SPI interface mode is selected by
  35  * asserting CS low and sending the reset command (CMD0). The card will
  36  * respond with a (R1) response.
  37  *
  38  * CMD8 is optionally sent to determine the voltage range supported, and
  39  * indirectly determine whether it is a version 1.x SD/non-SD card or
  40  * version 2.x. I'll just ignore this for now.
  41  *
  42  * ACMD41 is repeatedly issued to initialise the card, until "in idle"
  43  * (bit 0) of the R1 response goes to '0', indicating it is initialised.
  44  *
  45  * You should also indicate whether the host supports High Capicity cards,
  46  * and check whether the card is high capacity - i'll also ignore this
  47  *
  48  * SPI Protocol
  49  * ------------
  50  * The SD SPI protocol is based on transactions made up of 8-bit words, with
  51  * the host starting every bus transaction by asserting the CS signal low. The
  52  * card always responds to commands, data blocks and errors.
  53  *
  54  * The protocol supports a CRC, but by default it is off (except for the
  55  * first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
  56  * I'll leave the CRC off I think!
  57  *
  58  * Standard capacity cards have variable data block sizes, whereas High
  59  * Capacity cards fix the size of data block to 512 bytes. I'll therefore
  60  * just always use the Standard Capacity cards with a block size of 512 bytes.
  61  * This is set with CMD16.
  62  *
  63  * You can read and write single blocks (CMD17, CMD25) or multiple blocks
  64  * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
  65  * the card gets a read command, it responds with a response token, and then
  66  * a data token or an error.
  67  *
  68  * SPI Command Format
  69  * ------------------
  70  * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
  71  *
  72  * +---------------+------------+------------+-----------+----------+--------------+
  73  * | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 |
  74  * +---------------+------------+------------+-----------+----------+--------------+
  75  *
  76  * As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
  77  *
  78  * All Application Specific commands shall be preceded with APP_CMD (CMD55).
  79  *
  80  * SPI Response Format
  81  * -------------------
  82  * The main response format (R1) is a status byte (normally zero). Key flags:
  83  *  idle - 1 if the card is in an idle state/initialising
  84  *  cmd  - 1 if an illegal command code was detected
  85  *
  86  *    +-------------------------------------------------+
  87  * R1 | 0 | arg | addr | seq | crc | cmd | erase | idle |
  88  *    +-------------------------------------------------+
  89  *
  90  * R1b is the same, except it is followed by a busy signal (zeros) until
  91  * the first non-zero byte when it is ready again.
  92  *
  93  * Data Response Token
  94  * -------------------
  95  * Every data block written to the card is acknowledged by a byte
  96  * response token
  97  *
  98  * +----------------------+
  99  * | xxx | 0 | status | 1 |
 100  * +----------------------+
 101  *              010 - OK!
 102  *              101 - CRC Error
 103  *              110 - Write Error
 104  *
 105  * Single Block Read and Write
 106  * ---------------------------
 107  *
 108  * Block transfers have a byte header, followed by the data, followed
 109  * by a 16-bit CRC. In our case, the data will always be 512 bytes.
 110  *
 111  * +------+---------+---------+- -  - -+---------+-----------+----------+
 112  * | 0xFE | data[0] | data[1] |        | data[n] | crc[15:8] | crc[7:0] |
 113  * +------+---------+---------+- -  - -+---------+-----------+----------+
 114  */
 115 #include "SDFileSystem.h"
 116 #include "mbed_debug.h"
 117
 118 #define SD_COMMAND_TIMEOUT 5000
 119
 120 #define SD_DBG             0
 121
 122 SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
 123     FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs), _is_initialized(0) {
 124     _cs = 1;
 125
 126     // Set default to 100kHz for initialisation and 1MHz for data transfer
 127     _init_sck = 100000;
 128     _transfer_sck = 1000000;
 129 }
 130
 131 #define R1_IDLE_STATE           (1 << 0)
 132 #define R1_ERASE_RESET          (1 << 1)
 133 #define R1_ILLEGAL_COMMAND      (1 << 2)
 134 #define R1_COM_CRC_ERROR        (1 << 3)
 135 #define R1_ERASE_SEQUENCE_ERROR (1 << 4)
 136 #define R1_ADDRESS_ERROR        (1 << 5)
 137 #define R1_PARAMETER_ERROR      (1 << 6)
 138
 139 // Types
 140 //  - v1.x Standard Capacity
 141 //  - v2.x Standard Capacity
 142 //  - v2.x High Capacity
 143 //  - Not recognised as an SD Card
 144 #define SDCARD_FAIL 0
 145 #define SDCARD_V1   1
 146 #define SDCARD_V2   2
 147 #define SDCARD_V2HC 3
 148
 149 int SDFileSystem::initialise_card() {
 150     // Set to SCK for initialisation, and clock card with cs = 1
 151     _spi.frequency(_init_sck);
 152     _cs = 1;
 153     for (int i = 0; i < 16; i++) {
 154         _spi.write(0xFF);
 155     }
 156
 157     // send CMD0, should return with all zeros except IDLE STATE set (bit 0)
 158     if (_cmd(0, 0) != R1_IDLE_STATE) {
 159         debug("No disk, or could not put SD card in to SPI idle state\n");
 160         return SDCARD_FAIL;
 161     }
 162
 163     // send CMD8 to determine whther it is ver 2.x
 164     int r = _cmd8();
 165     if (r == R1_IDLE_STATE) {
 166         return initialise_card_v2();
 167     } else if (r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
 168         return initialise_card_v1();
 169     } else {
 170         debug("Not in idle state after sending CMD8 (not an SD card?)\n");
 171         return SDCARD_FAIL;
 172     }
 173 }
 174
 175 int SDFileSystem::initialise_card_v1() {
 176     for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
 177         _cmd(55, 0);
 178         if (_cmd(41, 0) == 0) {
 179             cdv = 512;
 180             debug_if(SD_DBG, "\n\rInit: SEDCARD_V1\n\r");
 181             return SDCARD_V1;
 182         }
 183     }
 184
 185     debug("Timeout waiting for v1.x card\n");
 186     return SDCARD_FAIL;
 187 }
 188
 189 int SDFileSystem::initialise_card_v2() {
 190     for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
 191         wait_ms(50);
 192         _cmd58();
 193         _cmd(55, 0);
 194         if (_cmd(41, 0x40000000) == 0) {
 195             _cmd58();
 196             debug_if(SD_DBG, "\n\rInit: SDCARD_V2\n\r");
 197             cdv = 1;
 198             return SDCARD_V2;
 199         }
 200     }
 201
 202     debug("Timeout waiting for v2.x card\n");
 203     return SDCARD_FAIL;
 204 }
 205
 206 int SDFileSystem::disk_initialize() {
 207     _is_initialized = initialise_card();
 208     if (_is_initialized == 0) {
 209         debug("Fail to initialize card\n");
 210         return 1;
 211     }
 212     debug_if(SD_DBG, "init card = %d\n", _is_initialized);
 213     _sectors = _sd_sectors();
 214
 215     // Set block length to 512 (CMD16)
 216     if (_cmd(16, 512) != 0) {
 217         debug("Set 512-byte block timed out\n");
 218         return 1;
 219     }
 220
 221     // Set SCK for data transfer
 222     _spi.frequency(_transfer_sck);
 223     return 0;
 224 }
 225
 226 int SDFileSystem::disk_write(const uint8_t* buffer, uint64_t block_number, uint8_t count) {
 227     if (!_is_initialized) {
 228         return -1;
 229     }
 230
 231     for (uint64_t b = block_number; b < block_number + count; b++) {
 232         // set write address for single block (CMD24)
 233         if (_cmd(24, b * cdv) != 0) {
 234             return 1;
 235         }
 236
 237         // send the data block
 238         _write(buffer, 512);
 239         buffer += 512;
 240     }
 241
 242     return 0;
 243 }
 244
 245 int SDFileSystem::disk_read(uint8_t* buffer, uint64_t block_number, uint8_t count) {
 246     if (!_is_initialized) {
 247         return -1;
 248     }
 249
 250     for (uint64_t b = block_number; b < block_number + count; b++) {
 251         // set read address for single block (CMD17)
 252         if (_cmd(17, b * cdv) != 0) {
 253             return 1;
 254         }
 255
 256         // receive the data
 257         _read(buffer, 512);
 258         buffer += 512;
 259     }
 260
 261     return 0;
 262 }
 263
 264 int SDFileSystem::disk_status() {
 265     // FATFileSystem::disk_status() returns 0 when initialized
 266     if (_is_initialized) {
 267         return 0;
 268     } else {
 269         return 1;
 270     }
 271 }
 272
 273 int SDFileSystem::disk_sync() { return 0; }
 274 uint64_t SDFileSystem::disk_sectors() { return _sectors; }
 275
 276
 277 // PRIVATE FUNCTIONS
 278 int SDFileSystem::_cmd(int cmd, int arg) {
 279     _cs = 0;
 280
 281     // send a command
 282     _spi.write(0x40 | cmd);
 283     _spi.write(arg >> 24);
 284     _spi.write(arg >> 16);
 285     _spi.write(arg >> 8);
 286     _spi.write(arg >> 0);
 287     _spi.write(0x95);
 288
 289     // wait for the repsonse (response[7] == 0)
 290     for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
 291         int response = _spi.write(0xFF);
 292         if (!(response & 0x80)) {
 293             _cs = 1;
 294             _spi.write(0xFF);
 295             return response;
 296         }
 297     }
 298     _cs = 1;
 299     _spi.write(0xFF);
 300     return -1; // timeout
 301 }
 302 int SDFileSystem::_cmdx(int cmd, int arg) {
 303     _cs = 0;
 304
 305     // send a command
 306     _spi.write(0x40 | cmd);
 307     _spi.write(arg >> 24);
 308     _spi.write(arg >> 16);
 309     _spi.write(arg >> 8);
 310     _spi.write(arg >> 0);
 311     _spi.write(0x95);
 312
 313     // wait for the repsonse (response[7] == 0)
 314     for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
 315         int response = _spi.write(0xFF);
 316         if (!(response & 0x80)) {
 317             return response;
 318         }
 319     }
 320     _cs = 1;
 321     _spi.write(0xFF);
 322     return -1; // timeout
 323 }
 324
 325
 326 int SDFileSystem::_cmd58() {
 327     _cs = 0;
 328     int arg = 0;
 329
 330     // send a command
 331     _spi.write(0x40 | 58);
 332     _spi.write(arg >> 24);
 333     _spi.write(arg >> 16);
 334     _spi.write(arg >> 8);
 335     _spi.write(arg >> 0);
 336     _spi.write(0x95);
 337
 338     // wait for the repsonse (response[7] == 0)
 339     for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
 340         int response = _spi.write(0xFF);
 341         if (!(response & 0x80)) {
 342             int ocr = _spi.write(0xFF) << 24;
 343             ocr |= _spi.write(0xFF) << 16;
 344             ocr |= _spi.write(0xFF) << 8;
 345             ocr |= _spi.write(0xFF) << 0;
 346             _cs = 1;
 347             _spi.write(0xFF);
 348             return response;
 349         }
 350     }
 351     _cs = 1;
 352     _spi.write(0xFF);
 353     return -1; // timeout
 354 }
 355
 356 int SDFileSystem::_cmd8() {
 357     _cs = 0;
 358
 359     // send a command
 360     _spi.write(0x40 | 8); // CMD8
 361     _spi.write(0x00);     // reserved
 362     _spi.write(0x00);     // reserved
 363     _spi.write(0x01);     // 3.3v
 364     _spi.write(0xAA);     // check pattern
 365     _spi.write(0x87);     // crc
 366
 367     // wait for the repsonse (response[7] == 0)
 368     for (int i = 0; i < SD_COMMAND_TIMEOUT * 1000; i++) {
 369         char response[5];
 370         response[0] = _spi.write(0xFF);
 371         if (!(response[0] & 0x80)) {
 372             for (int j = 1; j < 5; j++) {
 373                 response[i] = _spi.write(0xFF);
 374             }
 375             _cs = 1;
 376             _spi.write(0xFF);
 377             return response[0];
 378         }
 379     }
 380     _cs = 1;
 381     _spi.write(0xFF);
 382     return -1; // timeout
 383 }
 384
 385 int SDFileSystem::_read(uint8_t *buffer, uint32_t length) {
 386     _cs = 0;
 387
 388     // read until start byte (0xFF)
 389     while (_spi.write(0xFF) != 0xFE);
 390
 391     // read data
 392     for (uint32_t i = 0; i < length; i++) {
 393         buffer[i] = _spi.write(0xFF);
 394     }
 395     _spi.write(0xFF); // checksum
 396     _spi.write(0xFF);
 397
 398     _cs = 1;
 399     _spi.write(0xFF);
 400     return 0;
 401 }
 402
 403 int SDFileSystem::_write(const uint8_t*buffer, uint32_t length) {
 404     _cs = 0;
 405
 406     // indicate start of block
 407     _spi.write(0xFE);
 408
 409     // write the data
 410     for (uint32_t i = 0; i < length; i++) {
 411         _spi.write(buffer[i]);
 412     }
 413
 414     // write the checksum
 415     _spi.write(0xFF);
 416     _spi.write(0xFF);
 417
 418     // check the response token
 419     if ((_spi.write(0xFF) & 0x1F) != 0x05) {
 420         _cs = 1;
 421         _spi.write(0xFF);
 422         return 1;
 423     }
 424
 425     // wait for write to finish
 426     while (_spi.write(0xFF) == 0);
 427
 428     _cs = 1;
 429     _spi.write(0xFF);
 430     return 0;
 431 }
 432
 433 static uint32_t ext_bits(unsigned char *data, int msb, int lsb) {
 434     uint32_t bits = 0;
 435     uint32_t size = 1 + msb - lsb;
 436     for (uint32_t i = 0; i < size; i++) {
 437         uint32_t position = lsb + i;
 438         uint32_t byte = 15 - (position >> 3);
 439         uint32_t bit = position & 0x7;
 440         uint32_t value = (data[byte] >> bit) & 1;
 441         bits |= value << i;
 442     }
 443     return bits;
 444 }
 445
 446 uint64_t SDFileSystem::_sd_sectors() {
 447     uint32_t c_size, c_size_mult, read_bl_len;
 448     uint32_t block_len, mult, blocknr, capacity;
 449     uint32_t hc_c_size;
 450     uint64_t blocks;
 451
 452     // CMD9, Response R2 (R1 byte + 16-byte block read)
 453     if (_cmdx(9, 0) != 0) {
 454         debug("Didn't get a response from the disk\n");
 455         return 0;
 456     }
 457
 458     uint8_t csd[16];
 459     if (_read(csd, 16) != 0) {
 460         debug("Couldn't read csd response from disk\n");
 461         return 0;
 462     }
 463
 464     // csd_structure : csd[127:126]
 465     // c_size        : csd[73:62]
 466     // c_size_mult   : csd[49:47]
 467     // read_bl_len   : csd[83:80] - the *maximum* read block length
 468
 469     int csd_structure = ext_bits(csd, 127, 126);
 470
 471     switch (csd_structure) {
 472         case 0:
 473             cdv = 512;
 474             c_size = ext_bits(csd, 73, 62);
 475             c_size_mult = ext_bits(csd, 49, 47);
 476             read_bl_len = ext_bits(csd, 83, 80);
 477
 478             block_len = 1 << read_bl_len;
 479             mult = 1 << (c_size_mult + 2);
 480             blocknr = (c_size + 1) * mult;
 481             capacity = blocknr * block_len;
 482             blocks = capacity / 512;
 483             debug_if(SD_DBG, "\n\rSDCard\n\rc_size: %d \n\rcapacity: %ld \n\rsectors: %lld\n\r", c_size, capacity, blocks);
 484             break;
 485
 486         case 1:
 487             cdv = 1;
 488             hc_c_size = ext_bits(csd, 63, 48);
 489             blocks = (hc_c_size+1)*1024;
 490             debug_if(SD_DBG, "\n\rSDHC Card \n\rhc_c_size: %d\n\rcapacity: %lld \n\rsectors: %lld\n\r", hc_c_size, blocks*512, blocks);
 491             break;
 492
 493         default:
 494             debug("CSD struct unsupported\r\n");
 495             return 0;
 496     };
 497     return blocks;
 498 }