hige dura
Dependencies: FatFileSystem mbed
SDFileSystem.cpp@2:307500c991dd, 2012-04-21 (annotated)
- Committer:
- higedura
- Date:
- Sat Apr 21 14:07:27 2012 +0000
- Revision:
- 2:307500c991dd
- Parent:
- 0:813b917360ac
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| higedura | 0:813b917360ac | 1 | /* mbed SDFileSystem Library, for providing file access to SD cards |
| higedura | 0:813b917360ac | 2 | * Copyright (c) 2008-2010, sford |
| higedura | 0:813b917360ac | 3 | * |
| higedura | 0:813b917360ac | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| higedura | 0:813b917360ac | 5 | * of this software and associated documentation files (the "Software"), to deal |
| higedura | 0:813b917360ac | 6 | * in the Software without restriction, including without limitation the rights |
| higedura | 0:813b917360ac | 7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| higedura | 0:813b917360ac | 8 | * copies of the Software, and to permit persons to whom the Software is |
| higedura | 0:813b917360ac | 9 | * furnished to do so, subject to the following conditions: |
| higedura | 0:813b917360ac | 10 | * |
| higedura | 0:813b917360ac | 11 | * The above copyright notice and this permission notice shall be included in |
| higedura | 0:813b917360ac | 12 | * all copies or substantial portions of the Software. |
| higedura | 0:813b917360ac | 13 | * |
| higedura | 0:813b917360ac | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| higedura | 0:813b917360ac | 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| higedura | 0:813b917360ac | 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| higedura | 0:813b917360ac | 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| higedura | 0:813b917360ac | 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| higedura | 0:813b917360ac | 19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| higedura | 0:813b917360ac | 20 | * THE SOFTWARE. |
| higedura | 0:813b917360ac | 21 | */ |
| higedura | 0:813b917360ac | 22 | |
| higedura | 0:813b917360ac | 23 | /* Introduction |
| higedura | 0:813b917360ac | 24 | * ------------ |
| higedura | 0:813b917360ac | 25 | * SD and MMC cards support a number of interfaces, but common to them all |
| higedura | 0:813b917360ac | 26 | * is one based on SPI. This is the one I'm implmenting because it means |
| higedura | 0:813b917360ac | 27 | * it is much more portable even though not so performant, and we already |
| higedura | 0:813b917360ac | 28 | * have the mbed SPI Interface! |
| higedura | 0:813b917360ac | 29 | * |
| higedura | 0:813b917360ac | 30 | * The main reference I'm using is Chapter 7, "SPI Mode" of: |
| higedura | 0:813b917360ac | 31 | * http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf |
| higedura | 0:813b917360ac | 32 | * |
| higedura | 0:813b917360ac | 33 | * SPI Startup |
| higedura | 0:813b917360ac | 34 | * ----------- |
| higedura | 0:813b917360ac | 35 | * The SD card powers up in SD mode. The SPI interface mode is selected by |
| higedura | 0:813b917360ac | 36 | * asserting CS low and sending the reset command (CMD0). The card will |
| higedura | 0:813b917360ac | 37 | * respond with a (R1) response. |
| higedura | 0:813b917360ac | 38 | * |
| higedura | 0:813b917360ac | 39 | * CMD8 is optionally sent to determine the voltage range supported, and |
| higedura | 0:813b917360ac | 40 | * indirectly determine whether it is a version 1.x SD/non-SD card or |
| higedura | 0:813b917360ac | 41 | * version 2.x. I'll just ignore this for now. |
| higedura | 0:813b917360ac | 42 | * |
| higedura | 0:813b917360ac | 43 | * ACMD41 is repeatedly issued to initialise the card, until "in idle" |
| higedura | 0:813b917360ac | 44 | * (bit 0) of the R1 response goes to '0', indicating it is initialised. |
| higedura | 0:813b917360ac | 45 | * |
| higedura | 0:813b917360ac | 46 | * You should also indicate whether the host supports High Capicity cards, |
| higedura | 0:813b917360ac | 47 | * and check whether the card is high capacity - i'll also ignore this |
| higedura | 0:813b917360ac | 48 | * |
| higedura | 0:813b917360ac | 49 | * SPI Protocol |
| higedura | 0:813b917360ac | 50 | * ------------ |
| higedura | 0:813b917360ac | 51 | * The SD SPI protocol is based on transactions made up of 8-bit words, with |
| higedura | 0:813b917360ac | 52 | * the host starting every bus transaction by asserting the CS signal low. The |
| higedura | 0:813b917360ac | 53 | * card always responds to commands, data blocks and errors. |
| higedura | 0:813b917360ac | 54 | * |
| higedura | 0:813b917360ac | 55 | * The protocol supports a CRC, but by default it is off (except for the |
| higedura | 0:813b917360ac | 56 | * first reset CMD0, where the CRC can just be pre-calculated, and CMD8) |
| higedura | 0:813b917360ac | 57 | * I'll leave the CRC off I think! |
| higedura | 0:813b917360ac | 58 | * |
| higedura | 0:813b917360ac | 59 | * Standard capacity cards have variable data block sizes, whereas High |
| higedura | 0:813b917360ac | 60 | * Capacity cards fix the size of data block to 512 bytes. I'll therefore |
| higedura | 0:813b917360ac | 61 | * just always use the Standard Capacity cards with a block size of 512 bytes. |
| higedura | 0:813b917360ac | 62 | * This is set with CMD16. |
| higedura | 0:813b917360ac | 63 | * |
| higedura | 0:813b917360ac | 64 | * You can read and write single blocks (CMD17, CMD25) or multiple blocks |
| higedura | 0:813b917360ac | 65 | * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When |
| higedura | 0:813b917360ac | 66 | * the card gets a read command, it responds with a response token, and then |
| higedura | 0:813b917360ac | 67 | * a data token or an error. |
| higedura | 0:813b917360ac | 68 | * |
| higedura | 0:813b917360ac | 69 | * SPI Command Format |
| higedura | 0:813b917360ac | 70 | * ------------------ |
| higedura | 0:813b917360ac | 71 | * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC. |
| higedura | 0:813b917360ac | 72 | * |
| higedura | 0:813b917360ac | 73 | * +---------------+------------+------------+-----------+----------+--------------+ |
| higedura | 0:813b917360ac | 74 | * | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 | |
| higedura | 0:813b917360ac | 75 | * +---------------+------------+------------+-----------+----------+--------------+ |
| higedura | 0:813b917360ac | 76 | * |
| higedura | 0:813b917360ac | 77 | * As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95) |
| higedura | 0:813b917360ac | 78 | * |
| higedura | 0:813b917360ac | 79 | * All Application Specific commands shall be preceded with APP_CMD (CMD55). |
| higedura | 0:813b917360ac | 80 | * |
| higedura | 0:813b917360ac | 81 | * SPI Response Format |
| higedura | 0:813b917360ac | 82 | * ------------------- |
| higedura | 0:813b917360ac | 83 | * The main response format (R1) is a status byte (normally zero). Key flags: |
| higedura | 0:813b917360ac | 84 | * idle - 1 if the card is in an idle state/initialising |
| higedura | 0:813b917360ac | 85 | * cmd - 1 if an illegal command code was detected |
| higedura | 0:813b917360ac | 86 | * |
| higedura | 0:813b917360ac | 87 | * +-------------------------------------------------+ |
| higedura | 0:813b917360ac | 88 | * R1 | 0 | arg | addr | seq | crc | cmd | erase | idle | |
| higedura | 0:813b917360ac | 89 | * +-------------------------------------------------+ |
| higedura | 0:813b917360ac | 90 | * |
| higedura | 0:813b917360ac | 91 | * R1b is the same, except it is followed by a busy signal (zeros) until |
| higedura | 0:813b917360ac | 92 | * the first non-zero byte when it is ready again. |
| higedura | 0:813b917360ac | 93 | * |
| higedura | 0:813b917360ac | 94 | * Data Response Token |
| higedura | 0:813b917360ac | 95 | * ------------------- |
| higedura | 0:813b917360ac | 96 | * Every data block written to the card is acknowledged by a byte |
| higedura | 0:813b917360ac | 97 | * response token |
| higedura | 0:813b917360ac | 98 | * |
| higedura | 0:813b917360ac | 99 | * +----------------------+ |
| higedura | 0:813b917360ac | 100 | * | xxx | 0 | status | 1 | |
| higedura | 0:813b917360ac | 101 | * +----------------------+ |
| higedura | 0:813b917360ac | 102 | * 010 - OK! |
| higedura | 0:813b917360ac | 103 | * 101 - CRC Error |
| higedura | 0:813b917360ac | 104 | * 110 - Write Error |
| higedura | 0:813b917360ac | 105 | * |
| higedura | 0:813b917360ac | 106 | * Single Block Read and Write |
| higedura | 0:813b917360ac | 107 | * --------------------------- |
| higedura | 0:813b917360ac | 108 | * |
| higedura | 0:813b917360ac | 109 | * Block transfers have a byte header, followed by the data, followed |
| higedura | 0:813b917360ac | 110 | * by a 16-bit CRC. In our case, the data will always be 512 bytes. |
| higedura | 0:813b917360ac | 111 | * |
| higedura | 0:813b917360ac | 112 | * +------+---------+---------+- - - -+---------+-----------+----------+ |
| higedura | 0:813b917360ac | 113 | * | 0xFE | data[0] | data[1] | | data[n] | crc[15:8] | crc[7:0] | |
| higedura | 0:813b917360ac | 114 | * +------+---------+---------+- - - -+---------+-----------+----------+ |
| higedura | 0:813b917360ac | 115 | */ |
| higedura | 0:813b917360ac | 116 | |
| higedura | 0:813b917360ac | 117 | #include "SDFileSystem.h" |
| higedura | 0:813b917360ac | 118 | |
| higedura | 0:813b917360ac | 119 | #define SD_COMMAND_TIMEOUT 5000 |
| higedura | 0:813b917360ac | 120 | |
| higedura | 0:813b917360ac | 121 | SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) : |
| higedura | 0:813b917360ac | 122 | FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) { |
| higedura | 0:813b917360ac | 123 | _cs = 1; |
| higedura | 0:813b917360ac | 124 | } |
| higedura | 0:813b917360ac | 125 | |
| higedura | 0:813b917360ac | 126 | #define R1_IDLE_STATE (1 << 0) |
| higedura | 0:813b917360ac | 127 | #define R1_ERASE_RESET (1 << 1) |
| higedura | 0:813b917360ac | 128 | #define R1_ILLEGAL_COMMAND (1 << 2) |
| higedura | 0:813b917360ac | 129 | #define R1_COM_CRC_ERROR (1 << 3) |
| higedura | 0:813b917360ac | 130 | #define R1_ERASE_SEQUENCE_ERROR (1 << 4) |
| higedura | 0:813b917360ac | 131 | #define R1_ADDRESS_ERROR (1 << 5) |
| higedura | 0:813b917360ac | 132 | #define R1_PARAMETER_ERROR (1 << 6) |
| higedura | 0:813b917360ac | 133 | |
| higedura | 0:813b917360ac | 134 | // Types |
| higedura | 0:813b917360ac | 135 | // - v1.x Standard Capacity |
| higedura | 0:813b917360ac | 136 | // - v2.x Standard Capacity |
| higedura | 0:813b917360ac | 137 | // - v2.x High Capacity |
| higedura | 0:813b917360ac | 138 | // - Not recognised as an SD Card |
| higedura | 0:813b917360ac | 139 | |
| higedura | 0:813b917360ac | 140 | #define SDCARD_FAIL 0 |
| higedura | 0:813b917360ac | 141 | #define SDCARD_V1 1 |
| higedura | 0:813b917360ac | 142 | #define SDCARD_V2 2 |
| higedura | 0:813b917360ac | 143 | #define SDCARD_V2HC 3 |
| higedura | 0:813b917360ac | 144 | |
| higedura | 0:813b917360ac | 145 | int SDFileSystem::initialise_card() { |
| higedura | 0:813b917360ac | 146 | // Set to 100kHz for initialisation, and clock card with cs = 1 |
| higedura | 0:813b917360ac | 147 | _spi.frequency(100000); |
| higedura | 0:813b917360ac | 148 | _cs = 1; |
| higedura | 0:813b917360ac | 149 | for(int i=0; i<16; i++) { |
| higedura | 0:813b917360ac | 150 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 151 | } |
| higedura | 0:813b917360ac | 152 | |
| higedura | 0:813b917360ac | 153 | // send CMD0, should return with all zeros except IDLE STATE set (bit 0) |
| higedura | 0:813b917360ac | 154 | if(_cmd(0, 0) != R1_IDLE_STATE) { |
| higedura | 0:813b917360ac | 155 | fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n"); |
| higedura | 0:813b917360ac | 156 | return SDCARD_FAIL; |
| higedura | 0:813b917360ac | 157 | } |
| higedura | 0:813b917360ac | 158 | |
| higedura | 0:813b917360ac | 159 | // send CMD8 to determine whther it is ver 2.x |
| higedura | 0:813b917360ac | 160 | int r = _cmd8(); |
| higedura | 0:813b917360ac | 161 | if(r == R1_IDLE_STATE) { |
| higedura | 0:813b917360ac | 162 | return initialise_card_v2(); |
| higedura | 0:813b917360ac | 163 | } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) { |
| higedura | 0:813b917360ac | 164 | return initialise_card_v1(); |
| higedura | 0:813b917360ac | 165 | } else { |
| higedura | 0:813b917360ac | 166 | fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n"); |
| higedura | 0:813b917360ac | 167 | return SDCARD_FAIL; |
| higedura | 0:813b917360ac | 168 | } |
| higedura | 0:813b917360ac | 169 | } |
| higedura | 0:813b917360ac | 170 | |
| higedura | 0:813b917360ac | 171 | int SDFileSystem::initialise_card_v1() { |
| higedura | 0:813b917360ac | 172 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| higedura | 0:813b917360ac | 173 | _cmd(55, 0); |
| higedura | 0:813b917360ac | 174 | if(_cmd(41, 0) == 0) { |
| higedura | 0:813b917360ac | 175 | return SDCARD_V1; |
| higedura | 0:813b917360ac | 176 | } |
| higedura | 0:813b917360ac | 177 | } |
| higedura | 0:813b917360ac | 178 | |
| higedura | 0:813b917360ac | 179 | fprintf(stderr, "Timeout waiting for v1.x card\n"); |
| higedura | 0:813b917360ac | 180 | return SDCARD_FAIL; |
| higedura | 0:813b917360ac | 181 | } |
| higedura | 0:813b917360ac | 182 | |
| higedura | 0:813b917360ac | 183 | int SDFileSystem::initialise_card_v2() { |
| higedura | 0:813b917360ac | 184 | |
| higedura | 0:813b917360ac | 185 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| higedura | 0:813b917360ac | 186 | _cmd(55, 0); |
| higedura | 0:813b917360ac | 187 | if(_cmd(41, 0) == 0) { |
| higedura | 0:813b917360ac | 188 | _cmd58(); |
| higedura | 0:813b917360ac | 189 | return SDCARD_V2; |
| higedura | 0:813b917360ac | 190 | } |
| higedura | 0:813b917360ac | 191 | } |
| higedura | 0:813b917360ac | 192 | |
| higedura | 0:813b917360ac | 193 | fprintf(stderr, "Timeout waiting for v2.x card\n"); |
| higedura | 0:813b917360ac | 194 | return SDCARD_FAIL; |
| higedura | 0:813b917360ac | 195 | } |
| higedura | 0:813b917360ac | 196 | |
| higedura | 0:813b917360ac | 197 | int SDFileSystem::disk_initialize() { |
| higedura | 0:813b917360ac | 198 | |
| higedura | 0:813b917360ac | 199 | int i = initialise_card(); |
| higedura | 0:813b917360ac | 200 | // printf("init card = %d\n", i); |
| higedura | 0:813b917360ac | 201 | // printf("OK\n"); |
| higedura | 0:813b917360ac | 202 | |
| higedura | 0:813b917360ac | 203 | _sectors = _sd_sectors(); |
| higedura | 0:813b917360ac | 204 | |
| higedura | 0:813b917360ac | 205 | // Set block length to 512 (CMD16) |
| higedura | 0:813b917360ac | 206 | if(_cmd(16, 512) != 0) { |
| higedura | 0:813b917360ac | 207 | fprintf(stderr, "Set 512-byte block timed out\n"); |
| higedura | 0:813b917360ac | 208 | return 1; |
| higedura | 0:813b917360ac | 209 | } |
| higedura | 0:813b917360ac | 210 | |
| higedura | 0:813b917360ac | 211 | _spi.frequency(1000000); // Set to 1MHz for data transfer |
| higedura | 0:813b917360ac | 212 | return 0; |
| higedura | 0:813b917360ac | 213 | } |
| higedura | 0:813b917360ac | 214 | |
| higedura | 0:813b917360ac | 215 | int SDFileSystem::disk_write(const char *buffer, int block_number) { |
| higedura | 0:813b917360ac | 216 | // set write address for single block (CMD24) |
| higedura | 0:813b917360ac | 217 | if(_cmd(24, block_number * 512) != 0) { |
| higedura | 0:813b917360ac | 218 | return 1; |
| higedura | 0:813b917360ac | 219 | } |
| higedura | 0:813b917360ac | 220 | |
| higedura | 0:813b917360ac | 221 | // send the data block |
| higedura | 0:813b917360ac | 222 | _write(buffer, 512); |
| higedura | 0:813b917360ac | 223 | return 0; |
| higedura | 0:813b917360ac | 224 | } |
| higedura | 0:813b917360ac | 225 | |
| higedura | 0:813b917360ac | 226 | int SDFileSystem::disk_read(char *buffer, int block_number) { |
| higedura | 0:813b917360ac | 227 | // set read address for single block (CMD17) |
| higedura | 0:813b917360ac | 228 | if(_cmd(17, block_number * 512) != 0) { |
| higedura | 0:813b917360ac | 229 | return 1; |
| higedura | 0:813b917360ac | 230 | } |
| higedura | 0:813b917360ac | 231 | |
| higedura | 0:813b917360ac | 232 | // receive the data |
| higedura | 0:813b917360ac | 233 | _read(buffer, 512); |
| higedura | 0:813b917360ac | 234 | return 0; |
| higedura | 0:813b917360ac | 235 | } |
| higedura | 0:813b917360ac | 236 | |
| higedura | 0:813b917360ac | 237 | int SDFileSystem::disk_status() { return 0; } |
| higedura | 0:813b917360ac | 238 | int SDFileSystem::disk_sync() { return 0; } |
| higedura | 0:813b917360ac | 239 | int SDFileSystem::disk_sectors() { return _sectors; } |
| higedura | 0:813b917360ac | 240 | |
| higedura | 0:813b917360ac | 241 | // PRIVATE FUNCTIONS |
| higedura | 0:813b917360ac | 242 | |
| higedura | 0:813b917360ac | 243 | int SDFileSystem::_cmd(int cmd, int arg) { |
| higedura | 0:813b917360ac | 244 | _cs = 0; |
| higedura | 0:813b917360ac | 245 | |
| higedura | 0:813b917360ac | 246 | // send a command |
| higedura | 0:813b917360ac | 247 | _spi.write(0x40 | cmd); |
| higedura | 0:813b917360ac | 248 | _spi.write(arg >> 24); |
| higedura | 0:813b917360ac | 249 | _spi.write(arg >> 16); |
| higedura | 0:813b917360ac | 250 | _spi.write(arg >> 8); |
| higedura | 0:813b917360ac | 251 | _spi.write(arg >> 0); |
| higedura | 0:813b917360ac | 252 | _spi.write(0x95); |
| higedura | 0:813b917360ac | 253 | |
| higedura | 0:813b917360ac | 254 | // wait for the repsonse (response[7] == 0) |
| higedura | 0:813b917360ac | 255 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| higedura | 0:813b917360ac | 256 | int response = _spi.write(0xFF); |
| higedura | 0:813b917360ac | 257 | if(!(response & 0x80)) { |
| higedura | 0:813b917360ac | 258 | _cs = 1; |
| higedura | 0:813b917360ac | 259 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 260 | return response; |
| higedura | 0:813b917360ac | 261 | } |
| higedura | 0:813b917360ac | 262 | } |
| higedura | 0:813b917360ac | 263 | _cs = 1; |
| higedura | 0:813b917360ac | 264 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 265 | return -1; // timeout |
| higedura | 0:813b917360ac | 266 | } |
| higedura | 0:813b917360ac | 267 | int SDFileSystem::_cmdx(int cmd, int arg) { |
| higedura | 0:813b917360ac | 268 | _cs = 0; |
| higedura | 0:813b917360ac | 269 | |
| higedura | 0:813b917360ac | 270 | // send a command |
| higedura | 0:813b917360ac | 271 | _spi.write(0x40 | cmd); |
| higedura | 0:813b917360ac | 272 | _spi.write(arg >> 24); |
| higedura | 0:813b917360ac | 273 | _spi.write(arg >> 16); |
| higedura | 0:813b917360ac | 274 | _spi.write(arg >> 8); |
| higedura | 0:813b917360ac | 275 | _spi.write(arg >> 0); |
| higedura | 0:813b917360ac | 276 | _spi.write(0x95); |
| higedura | 0:813b917360ac | 277 | |
| higedura | 0:813b917360ac | 278 | // wait for the repsonse (response[7] == 0) |
| higedura | 0:813b917360ac | 279 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| higedura | 0:813b917360ac | 280 | int response = _spi.write(0xFF); |
| higedura | 0:813b917360ac | 281 | if(!(response & 0x80)) { |
| higedura | 0:813b917360ac | 282 | return response; |
| higedura | 0:813b917360ac | 283 | } |
| higedura | 0:813b917360ac | 284 | } |
| higedura | 0:813b917360ac | 285 | _cs = 1; |
| higedura | 0:813b917360ac | 286 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 287 | return -1; // timeout |
| higedura | 0:813b917360ac | 288 | } |
| higedura | 0:813b917360ac | 289 | |
| higedura | 0:813b917360ac | 290 | |
| higedura | 0:813b917360ac | 291 | int SDFileSystem::_cmd58() { |
| higedura | 0:813b917360ac | 292 | _cs = 0; |
| higedura | 0:813b917360ac | 293 | int arg = 0; |
| higedura | 0:813b917360ac | 294 | |
| higedura | 0:813b917360ac | 295 | // send a command |
| higedura | 0:813b917360ac | 296 | _spi.write(0x40 | 58); |
| higedura | 0:813b917360ac | 297 | _spi.write(arg >> 24); |
| higedura | 0:813b917360ac | 298 | _spi.write(arg >> 16); |
| higedura | 0:813b917360ac | 299 | _spi.write(arg >> 8); |
| higedura | 0:813b917360ac | 300 | _spi.write(arg >> 0); |
| higedura | 0:813b917360ac | 301 | _spi.write(0x95); |
| higedura | 0:813b917360ac | 302 | |
| higedura | 0:813b917360ac | 303 | // wait for the repsonse (response[7] == 0) |
| higedura | 0:813b917360ac | 304 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| higedura | 0:813b917360ac | 305 | int response = _spi.write(0xFF); |
| higedura | 0:813b917360ac | 306 | if(!(response & 0x80)) { |
| higedura | 0:813b917360ac | 307 | int ocr = _spi.write(0xFF) << 24; |
| higedura | 0:813b917360ac | 308 | ocr |= _spi.write(0xFF) << 16; |
| higedura | 0:813b917360ac | 309 | ocr |= _spi.write(0xFF) << 8; |
| higedura | 0:813b917360ac | 310 | ocr |= _spi.write(0xFF) << 0; |
| higedura | 0:813b917360ac | 311 | // printf("OCR = 0x%08X\n", ocr); |
| higedura | 0:813b917360ac | 312 | _cs = 1; |
| higedura | 0:813b917360ac | 313 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 314 | return response; |
| higedura | 0:813b917360ac | 315 | } |
| higedura | 0:813b917360ac | 316 | } |
| higedura | 0:813b917360ac | 317 | _cs = 1; |
| higedura | 0:813b917360ac | 318 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 319 | return -1; // timeout |
| higedura | 0:813b917360ac | 320 | } |
| higedura | 0:813b917360ac | 321 | |
| higedura | 0:813b917360ac | 322 | int SDFileSystem::_cmd8() { |
| higedura | 0:813b917360ac | 323 | _cs = 0; |
| higedura | 0:813b917360ac | 324 | |
| higedura | 0:813b917360ac | 325 | // send a command |
| higedura | 0:813b917360ac | 326 | _spi.write(0x40 | 8); // CMD8 |
| higedura | 0:813b917360ac | 327 | _spi.write(0x00); // reserved |
| higedura | 0:813b917360ac | 328 | _spi.write(0x00); // reserved |
| higedura | 0:813b917360ac | 329 | _spi.write(0x01); // 3.3v |
| higedura | 0:813b917360ac | 330 | _spi.write(0xAA); // check pattern |
| higedura | 0:813b917360ac | 331 | _spi.write(0x87); // crc |
| higedura | 0:813b917360ac | 332 | |
| higedura | 0:813b917360ac | 333 | // wait for the repsonse (response[7] == 0) |
| higedura | 0:813b917360ac | 334 | for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) { |
| higedura | 0:813b917360ac | 335 | char response[5]; |
| higedura | 0:813b917360ac | 336 | response[0] = _spi.write(0xFF); |
| higedura | 0:813b917360ac | 337 | if(!(response[0] & 0x80)) { |
| higedura | 0:813b917360ac | 338 | for(int j=1; j<5; j++) { |
| higedura | 0:813b917360ac | 339 | response[i] = _spi.write(0xFF); |
| higedura | 0:813b917360ac | 340 | } |
| higedura | 0:813b917360ac | 341 | _cs = 1; |
| higedura | 0:813b917360ac | 342 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 343 | return response[0]; |
| higedura | 0:813b917360ac | 344 | } |
| higedura | 0:813b917360ac | 345 | } |
| higedura | 0:813b917360ac | 346 | _cs = 1; |
| higedura | 0:813b917360ac | 347 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 348 | return -1; // timeout |
| higedura | 0:813b917360ac | 349 | } |
| higedura | 0:813b917360ac | 350 | |
| higedura | 0:813b917360ac | 351 | int SDFileSystem::_read(char *buffer, int length) { |
| higedura | 0:813b917360ac | 352 | _cs = 0; |
| higedura | 0:813b917360ac | 353 | |
| higedura | 0:813b917360ac | 354 | // read until start byte (0xFF) |
| higedura | 0:813b917360ac | 355 | while(_spi.write(0xFF) != 0xFE); |
| higedura | 0:813b917360ac | 356 | |
| higedura | 0:813b917360ac | 357 | // read data |
| higedura | 0:813b917360ac | 358 | for(int i=0; i<length; i++) { |
| higedura | 0:813b917360ac | 359 | buffer[i] = _spi.write(0xFF); |
| higedura | 0:813b917360ac | 360 | } |
| higedura | 0:813b917360ac | 361 | _spi.write(0xFF); // checksum |
| higedura | 0:813b917360ac | 362 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 363 | |
| higedura | 0:813b917360ac | 364 | _cs = 1; |
| higedura | 0:813b917360ac | 365 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 366 | return 0; |
| higedura | 0:813b917360ac | 367 | } |
| higedura | 0:813b917360ac | 368 | |
| higedura | 0:813b917360ac | 369 | int SDFileSystem::_write(const char *buffer, int length) { |
| higedura | 0:813b917360ac | 370 | _cs = 0; |
| higedura | 0:813b917360ac | 371 | |
| higedura | 0:813b917360ac | 372 | // indicate start of block |
| higedura | 0:813b917360ac | 373 | _spi.write(0xFE); |
| higedura | 0:813b917360ac | 374 | |
| higedura | 0:813b917360ac | 375 | // write the data |
| higedura | 0:813b917360ac | 376 | for(int i=0; i<length; i++) { |
| higedura | 0:813b917360ac | 377 | _spi.write(buffer[i]); |
| higedura | 0:813b917360ac | 378 | } |
| higedura | 0:813b917360ac | 379 | |
| higedura | 0:813b917360ac | 380 | // write the checksum |
| higedura | 0:813b917360ac | 381 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 382 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 383 | |
| higedura | 0:813b917360ac | 384 | // check the repsonse token |
| higedura | 0:813b917360ac | 385 | if((_spi.write(0xFF) & 0x1F) != 0x05) { |
| higedura | 0:813b917360ac | 386 | _cs = 1; |
| higedura | 0:813b917360ac | 387 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 388 | return 1; |
| higedura | 0:813b917360ac | 389 | } |
| higedura | 0:813b917360ac | 390 | |
| higedura | 0:813b917360ac | 391 | // wait for write to finish |
| higedura | 0:813b917360ac | 392 | while(_spi.write(0xFF) == 0); |
| higedura | 0:813b917360ac | 393 | |
| higedura | 0:813b917360ac | 394 | _cs = 1; |
| higedura | 0:813b917360ac | 395 | _spi.write(0xFF); |
| higedura | 0:813b917360ac | 396 | return 0; |
| higedura | 0:813b917360ac | 397 | } |
| higedura | 0:813b917360ac | 398 | |
| higedura | 0:813b917360ac | 399 | static int ext_bits(char *data, int msb, int lsb) { |
| higedura | 0:813b917360ac | 400 | int bits = 0; |
| higedura | 0:813b917360ac | 401 | int size = 1 + msb - lsb; |
| higedura | 0:813b917360ac | 402 | for(int i=0; i<size; i++) { |
| higedura | 0:813b917360ac | 403 | int position = lsb + i; |
| higedura | 0:813b917360ac | 404 | int byte = 15 - (position >> 3); |
| higedura | 0:813b917360ac | 405 | int bit = position & 0x7; |
| higedura | 0:813b917360ac | 406 | int value = (data[byte] >> bit) & 1; |
| higedura | 0:813b917360ac | 407 | bits |= value << i; |
| higedura | 0:813b917360ac | 408 | } |
| higedura | 0:813b917360ac | 409 | return bits; |
| higedura | 0:813b917360ac | 410 | } |
| higedura | 0:813b917360ac | 411 | |
| higedura | 0:813b917360ac | 412 | int SDFileSystem::_sd_sectors() { |
| higedura | 0:813b917360ac | 413 | |
| higedura | 0:813b917360ac | 414 | // CMD9, Response R2 (R1 byte + 16-byte block read) |
| higedura | 0:813b917360ac | 415 | if(_cmdx(9, 0) != 0) { |
| higedura | 0:813b917360ac | 416 | fprintf(stderr, "Didn't get a response from the disk\n"); |
| higedura | 0:813b917360ac | 417 | return 0; |
| higedura | 0:813b917360ac | 418 | } |
| higedura | 0:813b917360ac | 419 | |
| higedura | 0:813b917360ac | 420 | char csd[16]; |
| higedura | 0:813b917360ac | 421 | if(_read(csd, 16) != 0) { |
| higedura | 0:813b917360ac | 422 | fprintf(stderr, "Couldn't read csd response from disk\n"); |
| higedura | 0:813b917360ac | 423 | return 0; |
| higedura | 0:813b917360ac | 424 | } |
| higedura | 0:813b917360ac | 425 | |
| higedura | 0:813b917360ac | 426 | // csd_structure : csd[127:126] |
| higedura | 0:813b917360ac | 427 | // c_size : csd[73:62] |
| higedura | 0:813b917360ac | 428 | // c_size_mult : csd[49:47] |
| higedura | 0:813b917360ac | 429 | // read_bl_len : csd[83:80] - the *maximum* read block length |
| higedura | 0:813b917360ac | 430 | |
| higedura | 0:813b917360ac | 431 | int csd_structure = ext_bits(csd, 127, 126); |
| higedura | 0:813b917360ac | 432 | int c_size = ext_bits(csd, 73, 62); |
| higedura | 0:813b917360ac | 433 | int c_size_mult = ext_bits(csd, 49, 47); |
| higedura | 0:813b917360ac | 434 | int read_bl_len = ext_bits(csd, 83, 80); |
| higedura | 0:813b917360ac | 435 | |
| higedura | 0:813b917360ac | 436 | // printf("CSD_STRUCT = %d\n", csd_structure); |
| higedura | 0:813b917360ac | 437 | |
| higedura | 0:813b917360ac | 438 | if(csd_structure != 0) { |
| higedura | 0:813b917360ac | 439 | fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n"); |
| higedura | 0:813b917360ac | 440 | return 0; |
| higedura | 0:813b917360ac | 441 | } |
| higedura | 0:813b917360ac | 442 | |
| higedura | 0:813b917360ac | 443 | // memory capacity = BLOCKNR * BLOCK_LEN |
| higedura | 0:813b917360ac | 444 | // where |
| higedura | 0:813b917360ac | 445 | // BLOCKNR = (C_SIZE+1) * MULT |
| higedura | 0:813b917360ac | 446 | // MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8) |
| higedura | 0:813b917360ac | 447 | // BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12) |
| higedura | 0:813b917360ac | 448 | |
| higedura | 0:813b917360ac | 449 | int block_len = 1 << read_bl_len; |
| higedura | 0:813b917360ac | 450 | int mult = 1 << (c_size_mult + 2); |
| higedura | 0:813b917360ac | 451 | int blocknr = (c_size + 1) * mult; |
| higedura | 0:813b917360ac | 452 | int capacity = blocknr * block_len; |
| higedura | 0:813b917360ac | 453 | |
| higedura | 0:813b917360ac | 454 | int blocks = capacity / 512; |
| higedura | 0:813b917360ac | 455 | |
| higedura | 0:813b917360ac | 456 | return blocks; |
| higedura | 0:813b917360ac | 457 | } |