Alex Allen
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SDFileSystem/SDFileSystem.cpp@0:feaa05d35ccf, 2012-03-07 (annotated)
- Committer:
- AlexAllen
- Date:
- Wed Mar 07 20:02:35 2012 +0000
- Revision:
- 0:feaa05d35ccf
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| AlexAllen | 0:feaa05d35ccf | 1 | /* mbed SDFileSystem Library, for providing file access to SD cards |
| AlexAllen | 0:feaa05d35ccf | 2 | * Copyright (c) 2008-2010, sford |
| AlexAllen | 0:feaa05d35ccf | 3 | * |
| AlexAllen | 0:feaa05d35ccf | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| AlexAllen | 0:feaa05d35ccf | 5 | * of this software and associated documentation files (the "Software"), to deal |
| AlexAllen | 0:feaa05d35ccf | 6 | * in the Software without restriction, including without limitation the rights |
| AlexAllen | 0:feaa05d35ccf | 7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| AlexAllen | 0:feaa05d35ccf | 8 | * copies of the Software, and to permit persons to whom the Software is |
| AlexAllen | 0:feaa05d35ccf | 9 | * furnished to do so, subject to the following conditions: |
| AlexAllen | 0:feaa05d35ccf | 10 | * |
| AlexAllen | 0:feaa05d35ccf | 11 | * The above copyright notice and this permission notice shall be included in |
| AlexAllen | 0:feaa05d35ccf | 12 | * all copies or substantial portions of the Software. |
| AlexAllen | 0:feaa05d35ccf | 13 | * |
| AlexAllen | 0:feaa05d35ccf | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| AlexAllen | 0:feaa05d35ccf | 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| AlexAllen | 0:feaa05d35ccf | 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| AlexAllen | 0:feaa05d35ccf | 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| AlexAllen | 0:feaa05d35ccf | 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| AlexAllen | 0:feaa05d35ccf | 19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| AlexAllen | 0:feaa05d35ccf | 20 | * THE SOFTWARE. |
| AlexAllen | 0:feaa05d35ccf | 21 | */ |
| AlexAllen | 0:feaa05d35ccf | 22 | |
| AlexAllen | 0:feaa05d35ccf | 23 | /* Introduction |
| AlexAllen | 0:feaa05d35ccf | 24 | * ------------ |
| AlexAllen | 0:feaa05d35ccf | 25 | * SD and MMC cards support a number of interfaces, but common to them all |
| AlexAllen | 0:feaa05d35ccf | 26 | * is one based on SPI. This is the one I'm implmenting because it means |
| AlexAllen | 0:feaa05d35ccf | 27 | * it is much more portable even though not so performant, and we already |
| AlexAllen | 0:feaa05d35ccf | 28 | * have the mbed SPI Interface! |
| AlexAllen | 0:feaa05d35ccf | 29 | * |
| AlexAllen | 0:feaa05d35ccf | 30 | * The main reference I'm using is Chapter 7, "SPI Mode" of: |
| AlexAllen | 0:feaa05d35ccf | 31 | * http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf |
| AlexAllen | 0:feaa05d35ccf | 32 | * |
| AlexAllen | 0:feaa05d35ccf | 33 | * SPI Startup |
| AlexAllen | 0:feaa05d35ccf | 34 | * ----------- |
| AlexAllen | 0:feaa05d35ccf | 35 | * The SD card powers up in SD mode. The SPI interface mode is selected by |
| AlexAllen | 0:feaa05d35ccf | 36 | * asserting CS low and sending the reset command (CMD0). The card will |
| AlexAllen | 0:feaa05d35ccf | 37 | * respond with a (R1) response. |
| AlexAllen | 0:feaa05d35ccf | 38 | * |
| AlexAllen | 0:feaa05d35ccf | 39 | * CMD8 is optionally sent to determine the voltage range supported, and |
| AlexAllen | 0:feaa05d35ccf | 40 | * indirectly determine whether it is a version 1.x SD/non-SD card or |
| AlexAllen | 0:feaa05d35ccf | 41 | * version 2.x. I'll just ignore this for now. |
| AlexAllen | 0:feaa05d35ccf | 42 | * |
| AlexAllen | 0:feaa05d35ccf | 43 | * ACMD41 is repeatedly issued to initialise the card, until "in idle" |
| AlexAllen | 0:feaa05d35ccf | 44 | * (bit 0) of the R1 response goes to '0', indicating it is initialised. |
| AlexAllen | 0:feaa05d35ccf | 45 | * |
| AlexAllen | 0:feaa05d35ccf | 46 | * You should also indicate whether the host supports High Capicity cards, |
| AlexAllen | 0:feaa05d35ccf | 47 | * and check whether the card is high capacity - i'll also ignore this |
| AlexAllen | 0:feaa05d35ccf | 48 | * |
| AlexAllen | 0:feaa05d35ccf | 49 | * SPI Protocol |
| AlexAllen | 0:feaa05d35ccf | 50 | * ------------ |
| AlexAllen | 0:feaa05d35ccf | 51 | * The SD SPI protocol is based on transactions made up of 8-bit words, with |
| AlexAllen | 0:feaa05d35ccf | 52 | * the host starting every bus transaction by asserting the CS signal low. The |
| AlexAllen | 0:feaa05d35ccf | 53 | * card always responds to commands, data blocks and errors. |
| AlexAllen | 0:feaa05d35ccf | 54 | * |
| AlexAllen | 0:feaa05d35ccf | 55 | * The protocol supports a CRC, but by default it is off (except for the |
| AlexAllen | 0:feaa05d35ccf | 56 | * first reset CMD0, where the CRC can just be pre-calculated, and CMD8) |
| AlexAllen | 0:feaa05d35ccf | 57 | * I'll leave the CRC off I think! |
| AlexAllen | 0:feaa05d35ccf | 58 | * |
| AlexAllen | 0:feaa05d35ccf | 59 | * Standard capacity cards have variable data block sizes, whereas High |
| AlexAllen | 0:feaa05d35ccf | 60 | * Capacity cards fix the size of data block to 512 bytes. I'll therefore |
| AlexAllen | 0:feaa05d35ccf | 61 | * just always use the Standard Capacity cards with a block size of 512 bytes. |
| AlexAllen | 0:feaa05d35ccf | 62 | * This is set with CMD16. |
| AlexAllen | 0:feaa05d35ccf | 63 | * |
| AlexAllen | 0:feaa05d35ccf | 64 | * You can read and write single blocks (CMD17, CMD25) or multiple blocks |
| AlexAllen | 0:feaa05d35ccf | 65 | * (CMD18, CMD25). For simplicity, I'll just use single block accesses. When |
| AlexAllen | 0:feaa05d35ccf | 66 | * the card gets a read command, it responds with a response token, and then |
| AlexAllen | 0:feaa05d35ccf | 67 | * a data token or an error. |
| AlexAllen | 0:feaa05d35ccf | 68 | * |
| AlexAllen | 0:feaa05d35ccf | 69 | * SPI Command Format |
| AlexAllen | 0:feaa05d35ccf | 70 | * ------------------ |
| AlexAllen | 0:feaa05d35ccf | 71 | * Commands are 6-bytes long, containing the command, 32-bit argument, and CRC. |
| AlexAllen | 0:feaa05d35ccf | 72 | * |
| AlexAllen | 0:feaa05d35ccf | 73 | * +---------------+------------+------------+-----------+----------+--------------+ |
| AlexAllen | 0:feaa05d35ccf | 74 | * | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 | |
| AlexAllen | 0:feaa05d35ccf | 75 | * +---------------+------------+------------+-----------+----------+--------------+ |
| AlexAllen | 0:feaa05d35ccf | 76 | * |
| AlexAllen | 0:feaa05d35ccf | 77 | * As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95) |
| AlexAllen | 0:feaa05d35ccf | 78 | * |
| AlexAllen | 0:feaa05d35ccf | 79 | * All Application Specific commands shall be preceded with APP_CMD (CMD55). |
| AlexAllen | 0:feaa05d35ccf | 80 | * |
| AlexAllen | 0:feaa05d35ccf | 81 | * SPI Response Format |
| AlexAllen | 0:feaa05d35ccf | 82 | * ------------------- |
| AlexAllen | 0:feaa05d35ccf | 83 | * The main response format (R1) is a status byte (normally zero). Key flags: |
| AlexAllen | 0:feaa05d35ccf | 84 | * idle - 1 if the card is in an idle state/initialising |
| AlexAllen | 0:feaa05d35ccf | 85 | * cmd - 1 if an illegal command code was detected |
| AlexAllen | 0:feaa05d35ccf | 86 | * |
| AlexAllen | 0:feaa05d35ccf | 87 | * +-------------------------------------------------+ |
| AlexAllen | 0:feaa05d35ccf | 88 | * R1 | 0 | arg | addr | seq | crc | cmd | erase | idle | |
| AlexAllen | 0:feaa05d35ccf | 89 | * +-------------------------------------------------+ |
| AlexAllen | 0:feaa05d35ccf | 90 | * |
| AlexAllen | 0:feaa05d35ccf | 91 | * R1b is the same, except it is followed by a busy signal (zeros) until |
| AlexAllen | 0:feaa05d35ccf | 92 | * the first non-zero byte when it is ready again. |
| AlexAllen | 0:feaa05d35ccf | 93 | * |
| AlexAllen | 0:feaa05d35ccf | 94 | * Data Response Token |
| AlexAllen | 0:feaa05d35ccf | 95 | * ------------------- |
| AlexAllen | 0:feaa05d35ccf | 96 | * Every data block written to the card is acknowledged by a byte |
| AlexAllen | 0:feaa05d35ccf | 97 | * response token |
| AlexAllen | 0:feaa05d35ccf | 98 | * |
| AlexAllen | 0:feaa05d35ccf | 99 | * +----------------------+ |
| AlexAllen | 0:feaa05d35ccf | 100 | * | xxx | 0 | status | 1 | |
| AlexAllen | 0:feaa05d35ccf | 101 | * +----------------------+ |
| AlexAllen | 0:feaa05d35ccf | 102 | * 010 - OK! |
| AlexAllen | 0:feaa05d35ccf | 103 | * 101 - CRC Error |
| AlexAllen | 0:feaa05d35ccf | 104 | * 110 - Write Error |
| AlexAllen | 0:feaa05d35ccf | 105 | * |
| AlexAllen | 0:feaa05d35ccf | 106 | * Single Block Read and Write |
| AlexAllen | 0:feaa05d35ccf | 107 | * --------------------------- |
| AlexAllen | 0:feaa05d35ccf | 108 | * |
| AlexAllen | 0:feaa05d35ccf | 109 | * Block transfers have a byte header, followed by the data, followed |
| AlexAllen | 0:feaa05d35ccf | 110 | * by a 16-bit CRC. In our case, the data will always be 512 bytes. |
| AlexAllen | 0:feaa05d35ccf | 111 | * |
| AlexAllen | 0:feaa05d35ccf | 112 | * +------+---------+---------+- - - -+---------+-----------+----------+ |
| AlexAllen | 0:feaa05d35ccf | 113 | * | 0xFE | data[0] | data[1] | | data[n] | crc[15:8] | crc[7:0] | |
| AlexAllen | 0:feaa05d35ccf | 114 | * +------+---------+---------+- - - -+---------+-----------+----------+ |
| AlexAllen | 0:feaa05d35ccf | 115 | */ |
| AlexAllen | 0:feaa05d35ccf | 116 | |
| AlexAllen | 0:feaa05d35ccf | 117 | #include "SDFileSystem.h" |
| AlexAllen | 0:feaa05d35ccf | 118 | |
| AlexAllen | 0:feaa05d35ccf | 119 | #define SD_COMMAND_TIMEOUT 5000 |
| AlexAllen | 0:feaa05d35ccf | 120 | |
| AlexAllen | 0:feaa05d35ccf | 121 | SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) : |
| AlexAllen | 0:feaa05d35ccf | 122 | FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) { |
| AlexAllen | 0:feaa05d35ccf | 123 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 124 | } |
| AlexAllen | 0:feaa05d35ccf | 125 | |
| AlexAllen | 0:feaa05d35ccf | 126 | #define R1_IDLE_STATE (1 << 0) |
| AlexAllen | 0:feaa05d35ccf | 127 | #define R1_ERASE_RESET (1 << 1) |
| AlexAllen | 0:feaa05d35ccf | 128 | #define R1_ILLEGAL_COMMAND (1 << 2) |
| AlexAllen | 0:feaa05d35ccf | 129 | #define R1_COM_CRC_ERROR (1 << 3) |
| AlexAllen | 0:feaa05d35ccf | 130 | #define R1_ERASE_SEQUENCE_ERROR (1 << 4) |
| AlexAllen | 0:feaa05d35ccf | 131 | #define R1_ADDRESS_ERROR (1 << 5) |
| AlexAllen | 0:feaa05d35ccf | 132 | #define R1_PARAMETER_ERROR (1 << 6) |
| AlexAllen | 0:feaa05d35ccf | 133 | |
| AlexAllen | 0:feaa05d35ccf | 134 | // Types |
| AlexAllen | 0:feaa05d35ccf | 135 | // - v1.x Standard Capacity |
| AlexAllen | 0:feaa05d35ccf | 136 | // - v2.x Standard Capacity |
| AlexAllen | 0:feaa05d35ccf | 137 | // - v2.x High Capacity |
| AlexAllen | 0:feaa05d35ccf | 138 | // - Not recognised as an SD Card |
| AlexAllen | 0:feaa05d35ccf | 139 | |
| AlexAllen | 0:feaa05d35ccf | 140 | #define SDCARD_FAIL 0 |
| AlexAllen | 0:feaa05d35ccf | 141 | #define SDCARD_V1 1 |
| AlexAllen | 0:feaa05d35ccf | 142 | #define SDCARD_V2 2 |
| AlexAllen | 0:feaa05d35ccf | 143 | #define SDCARD_V2HC 3 |
| AlexAllen | 0:feaa05d35ccf | 144 | |
| AlexAllen | 0:feaa05d35ccf | 145 | int SDFileSystem::initialise_card() { |
| AlexAllen | 0:feaa05d35ccf | 146 | // Set to 100kHz for initialisation, and clock card with cs = 1 |
| AlexAllen | 0:feaa05d35ccf | 147 | _spi.frequency(100000); |
| AlexAllen | 0:feaa05d35ccf | 148 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 149 | for(int i=0; i<16; i++) { |
| AlexAllen | 0:feaa05d35ccf | 150 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 151 | } |
| AlexAllen | 0:feaa05d35ccf | 152 | |
| AlexAllen | 0:feaa05d35ccf | 153 | // send CMD0, should return with all zeros except IDLE STATE set (bit 0) |
| AlexAllen | 0:feaa05d35ccf | 154 | if(_cmd(0, 0) != R1_IDLE_STATE) { |
| AlexAllen | 0:feaa05d35ccf | 155 | fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n"); |
| AlexAllen | 0:feaa05d35ccf | 156 | return SDCARD_FAIL; |
| AlexAllen | 0:feaa05d35ccf | 157 | } |
| AlexAllen | 0:feaa05d35ccf | 158 | |
| AlexAllen | 0:feaa05d35ccf | 159 | // send CMD8 to determine whther it is ver 2.x |
| AlexAllen | 0:feaa05d35ccf | 160 | int r = _cmd8(); |
| AlexAllen | 0:feaa05d35ccf | 161 | if(r == R1_IDLE_STATE) { |
| AlexAllen | 0:feaa05d35ccf | 162 | return initialise_card_v2(); |
| AlexAllen | 0:feaa05d35ccf | 163 | } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) { |
| AlexAllen | 0:feaa05d35ccf | 164 | return initialise_card_v1(); |
| AlexAllen | 0:feaa05d35ccf | 165 | } else { |
| AlexAllen | 0:feaa05d35ccf | 166 | fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n"); |
| AlexAllen | 0:feaa05d35ccf | 167 | return SDCARD_FAIL; |
| AlexAllen | 0:feaa05d35ccf | 168 | } |
| AlexAllen | 0:feaa05d35ccf | 169 | } |
| AlexAllen | 0:feaa05d35ccf | 170 | |
| AlexAllen | 0:feaa05d35ccf | 171 | int SDFileSystem::initialise_card_v1() { |
| AlexAllen | 0:feaa05d35ccf | 172 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| AlexAllen | 0:feaa05d35ccf | 173 | _cmd(55, 0); |
| AlexAllen | 0:feaa05d35ccf | 174 | if(_cmd(41, 0) == 0) { |
| AlexAllen | 0:feaa05d35ccf | 175 | return SDCARD_V1; |
| AlexAllen | 0:feaa05d35ccf | 176 | } |
| AlexAllen | 0:feaa05d35ccf | 177 | } |
| AlexAllen | 0:feaa05d35ccf | 178 | |
| AlexAllen | 0:feaa05d35ccf | 179 | fprintf(stderr, "Timeout waiting for v1.x card\n"); |
| AlexAllen | 0:feaa05d35ccf | 180 | return SDCARD_FAIL; |
| AlexAllen | 0:feaa05d35ccf | 181 | } |
| AlexAllen | 0:feaa05d35ccf | 182 | |
| AlexAllen | 0:feaa05d35ccf | 183 | int SDFileSystem::initialise_card_v2() { |
| AlexAllen | 0:feaa05d35ccf | 184 | |
| AlexAllen | 0:feaa05d35ccf | 185 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| AlexAllen | 0:feaa05d35ccf | 186 | _cmd(55, 0); |
| AlexAllen | 0:feaa05d35ccf | 187 | if(_cmd(41, 0) == 0) { |
| AlexAllen | 0:feaa05d35ccf | 188 | _cmd58(); |
| AlexAllen | 0:feaa05d35ccf | 189 | return SDCARD_V2; |
| AlexAllen | 0:feaa05d35ccf | 190 | } |
| AlexAllen | 0:feaa05d35ccf | 191 | } |
| AlexAllen | 0:feaa05d35ccf | 192 | |
| AlexAllen | 0:feaa05d35ccf | 193 | fprintf(stderr, "Timeout waiting for v2.x card\n"); |
| AlexAllen | 0:feaa05d35ccf | 194 | return SDCARD_FAIL; |
| AlexAllen | 0:feaa05d35ccf | 195 | } |
| AlexAllen | 0:feaa05d35ccf | 196 | |
| AlexAllen | 0:feaa05d35ccf | 197 | int SDFileSystem::disk_initialize() { |
| AlexAllen | 0:feaa05d35ccf | 198 | |
| AlexAllen | 0:feaa05d35ccf | 199 | int i = initialise_card(); |
| AlexAllen | 0:feaa05d35ccf | 200 | // printf("init card = %d\n", i); |
| AlexAllen | 0:feaa05d35ccf | 201 | // printf("OK\n"); |
| AlexAllen | 0:feaa05d35ccf | 202 | |
| AlexAllen | 0:feaa05d35ccf | 203 | _sectors = _sd_sectors(); |
| AlexAllen | 0:feaa05d35ccf | 204 | |
| AlexAllen | 0:feaa05d35ccf | 205 | // Set block length to 512 (CMD16) |
| AlexAllen | 0:feaa05d35ccf | 206 | if(_cmd(16, 512) != 0) { |
| AlexAllen | 0:feaa05d35ccf | 207 | fprintf(stderr, "Set 512-byte block timed out\n"); |
| AlexAllen | 0:feaa05d35ccf | 208 | return 1; |
| AlexAllen | 0:feaa05d35ccf | 209 | } |
| AlexAllen | 0:feaa05d35ccf | 210 | |
| AlexAllen | 0:feaa05d35ccf | 211 | _spi.frequency(1000000); // Set to 1MHz for data transfer |
| AlexAllen | 0:feaa05d35ccf | 212 | return 0; |
| AlexAllen | 0:feaa05d35ccf | 213 | } |
| AlexAllen | 0:feaa05d35ccf | 214 | |
| AlexAllen | 0:feaa05d35ccf | 215 | int SDFileSystem::disk_write(const char *buffer, int block_number) { |
| AlexAllen | 0:feaa05d35ccf | 216 | // set write address for single block (CMD24) |
| AlexAllen | 0:feaa05d35ccf | 217 | if(_cmd(24, block_number * 512) != 0) { |
| AlexAllen | 0:feaa05d35ccf | 218 | return 1; |
| AlexAllen | 0:feaa05d35ccf | 219 | } |
| AlexAllen | 0:feaa05d35ccf | 220 | |
| AlexAllen | 0:feaa05d35ccf | 221 | // send the data block |
| AlexAllen | 0:feaa05d35ccf | 222 | _write(buffer, 512); |
| AlexAllen | 0:feaa05d35ccf | 223 | return 0; |
| AlexAllen | 0:feaa05d35ccf | 224 | } |
| AlexAllen | 0:feaa05d35ccf | 225 | |
| AlexAllen | 0:feaa05d35ccf | 226 | int SDFileSystem::disk_read(char *buffer, int block_number) { |
| AlexAllen | 0:feaa05d35ccf | 227 | // set read address for single block (CMD17) |
| AlexAllen | 0:feaa05d35ccf | 228 | if(_cmd(17, block_number * 512) != 0) { |
| AlexAllen | 0:feaa05d35ccf | 229 | return 1; |
| AlexAllen | 0:feaa05d35ccf | 230 | } |
| AlexAllen | 0:feaa05d35ccf | 231 | |
| AlexAllen | 0:feaa05d35ccf | 232 | // receive the data |
| AlexAllen | 0:feaa05d35ccf | 233 | _read(buffer, 512); |
| AlexAllen | 0:feaa05d35ccf | 234 | return 0; |
| AlexAllen | 0:feaa05d35ccf | 235 | } |
| AlexAllen | 0:feaa05d35ccf | 236 | |
| AlexAllen | 0:feaa05d35ccf | 237 | int SDFileSystem::disk_status() { return 0; } |
| AlexAllen | 0:feaa05d35ccf | 238 | int SDFileSystem::disk_sync() { return 0; } |
| AlexAllen | 0:feaa05d35ccf | 239 | int SDFileSystem::disk_sectors() { return _sectors; } |
| AlexAllen | 0:feaa05d35ccf | 240 | |
| AlexAllen | 0:feaa05d35ccf | 241 | // PRIVATE FUNCTIONS |
| AlexAllen | 0:feaa05d35ccf | 242 | |
| AlexAllen | 0:feaa05d35ccf | 243 | int SDFileSystem::_cmd(int cmd, int arg) { |
| AlexAllen | 0:feaa05d35ccf | 244 | _cs = 0; |
| AlexAllen | 0:feaa05d35ccf | 245 | |
| AlexAllen | 0:feaa05d35ccf | 246 | // send a command |
| AlexAllen | 0:feaa05d35ccf | 247 | _spi.write(0x40 | cmd); |
| AlexAllen | 0:feaa05d35ccf | 248 | _spi.write(arg >> 24); |
| AlexAllen | 0:feaa05d35ccf | 249 | _spi.write(arg >> 16); |
| AlexAllen | 0:feaa05d35ccf | 250 | _spi.write(arg >> 8); |
| AlexAllen | 0:feaa05d35ccf | 251 | _spi.write(arg >> 0); |
| AlexAllen | 0:feaa05d35ccf | 252 | _spi.write(0x95); |
| AlexAllen | 0:feaa05d35ccf | 253 | |
| AlexAllen | 0:feaa05d35ccf | 254 | // wait for the repsonse (response[7] == 0) |
| AlexAllen | 0:feaa05d35ccf | 255 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| AlexAllen | 0:feaa05d35ccf | 256 | int response = _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 257 | if(!(response & 0x80)) { |
| AlexAllen | 0:feaa05d35ccf | 258 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 259 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 260 | return response; |
| AlexAllen | 0:feaa05d35ccf | 261 | } |
| AlexAllen | 0:feaa05d35ccf | 262 | } |
| AlexAllen | 0:feaa05d35ccf | 263 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 264 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 265 | return -1; // timeout |
| AlexAllen | 0:feaa05d35ccf | 266 | } |
| AlexAllen | 0:feaa05d35ccf | 267 | int SDFileSystem::_cmdx(int cmd, int arg) { |
| AlexAllen | 0:feaa05d35ccf | 268 | _cs = 0; |
| AlexAllen | 0:feaa05d35ccf | 269 | |
| AlexAllen | 0:feaa05d35ccf | 270 | // send a command |
| AlexAllen | 0:feaa05d35ccf | 271 | _spi.write(0x40 | cmd); |
| AlexAllen | 0:feaa05d35ccf | 272 | _spi.write(arg >> 24); |
| AlexAllen | 0:feaa05d35ccf | 273 | _spi.write(arg >> 16); |
| AlexAllen | 0:feaa05d35ccf | 274 | _spi.write(arg >> 8); |
| AlexAllen | 0:feaa05d35ccf | 275 | _spi.write(arg >> 0); |
| AlexAllen | 0:feaa05d35ccf | 276 | _spi.write(0x95); |
| AlexAllen | 0:feaa05d35ccf | 277 | |
| AlexAllen | 0:feaa05d35ccf | 278 | // wait for the repsonse (response[7] == 0) |
| AlexAllen | 0:feaa05d35ccf | 279 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| AlexAllen | 0:feaa05d35ccf | 280 | int response = _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 281 | if(!(response & 0x80)) { |
| AlexAllen | 0:feaa05d35ccf | 282 | return response; |
| AlexAllen | 0:feaa05d35ccf | 283 | } |
| AlexAllen | 0:feaa05d35ccf | 284 | } |
| AlexAllen | 0:feaa05d35ccf | 285 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 286 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 287 | return -1; // timeout |
| AlexAllen | 0:feaa05d35ccf | 288 | } |
| AlexAllen | 0:feaa05d35ccf | 289 | |
| AlexAllen | 0:feaa05d35ccf | 290 | |
| AlexAllen | 0:feaa05d35ccf | 291 | int SDFileSystem::_cmd58() { |
| AlexAllen | 0:feaa05d35ccf | 292 | _cs = 0; |
| AlexAllen | 0:feaa05d35ccf | 293 | int arg = 0; |
| AlexAllen | 0:feaa05d35ccf | 294 | |
| AlexAllen | 0:feaa05d35ccf | 295 | // send a command |
| AlexAllen | 0:feaa05d35ccf | 296 | _spi.write(0x40 | 58); |
| AlexAllen | 0:feaa05d35ccf | 297 | _spi.write(arg >> 24); |
| AlexAllen | 0:feaa05d35ccf | 298 | _spi.write(arg >> 16); |
| AlexAllen | 0:feaa05d35ccf | 299 | _spi.write(arg >> 8); |
| AlexAllen | 0:feaa05d35ccf | 300 | _spi.write(arg >> 0); |
| AlexAllen | 0:feaa05d35ccf | 301 | _spi.write(0x95); |
| AlexAllen | 0:feaa05d35ccf | 302 | |
| AlexAllen | 0:feaa05d35ccf | 303 | // wait for the repsonse (response[7] == 0) |
| AlexAllen | 0:feaa05d35ccf | 304 | for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { |
| AlexAllen | 0:feaa05d35ccf | 305 | int response = _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 306 | if(!(response & 0x80)) { |
| AlexAllen | 0:feaa05d35ccf | 307 | int ocr = _spi.write(0xFF) << 24; |
| AlexAllen | 0:feaa05d35ccf | 308 | ocr |= _spi.write(0xFF) << 16; |
| AlexAllen | 0:feaa05d35ccf | 309 | ocr |= _spi.write(0xFF) << 8; |
| AlexAllen | 0:feaa05d35ccf | 310 | ocr |= _spi.write(0xFF) << 0; |
| AlexAllen | 0:feaa05d35ccf | 311 | // printf("OCR = 0x%08X\n", ocr); |
| AlexAllen | 0:feaa05d35ccf | 312 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 313 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 314 | return response; |
| AlexAllen | 0:feaa05d35ccf | 315 | } |
| AlexAllen | 0:feaa05d35ccf | 316 | } |
| AlexAllen | 0:feaa05d35ccf | 317 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 318 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 319 | return -1; // timeout |
| AlexAllen | 0:feaa05d35ccf | 320 | } |
| AlexAllen | 0:feaa05d35ccf | 321 | |
| AlexAllen | 0:feaa05d35ccf | 322 | int SDFileSystem::_cmd8() { |
| AlexAllen | 0:feaa05d35ccf | 323 | _cs = 0; |
| AlexAllen | 0:feaa05d35ccf | 324 | |
| AlexAllen | 0:feaa05d35ccf | 325 | // send a command |
| AlexAllen | 0:feaa05d35ccf | 326 | _spi.write(0x40 | 8); // CMD8 |
| AlexAllen | 0:feaa05d35ccf | 327 | _spi.write(0x00); // reserved |
| AlexAllen | 0:feaa05d35ccf | 328 | _spi.write(0x00); // reserved |
| AlexAllen | 0:feaa05d35ccf | 329 | _spi.write(0x01); // 3.3v |
| AlexAllen | 0:feaa05d35ccf | 330 | _spi.write(0xAA); // check pattern |
| AlexAllen | 0:feaa05d35ccf | 331 | _spi.write(0x87); // crc |
| AlexAllen | 0:feaa05d35ccf | 332 | |
| AlexAllen | 0:feaa05d35ccf | 333 | // wait for the repsonse (response[7] == 0) |
| AlexAllen | 0:feaa05d35ccf | 334 | for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) { |
| AlexAllen | 0:feaa05d35ccf | 335 | char response[5]; |
| AlexAllen | 0:feaa05d35ccf | 336 | response[0] = _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 337 | if(!(response[0] & 0x80)) { |
| AlexAllen | 0:feaa05d35ccf | 338 | for(int j=1; j<5; j++) { |
| AlexAllen | 0:feaa05d35ccf | 339 | response[i] = _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 340 | } |
| AlexAllen | 0:feaa05d35ccf | 341 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 342 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 343 | return response[0]; |
| AlexAllen | 0:feaa05d35ccf | 344 | } |
| AlexAllen | 0:feaa05d35ccf | 345 | } |
| AlexAllen | 0:feaa05d35ccf | 346 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 347 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 348 | return -1; // timeout |
| AlexAllen | 0:feaa05d35ccf | 349 | } |
| AlexAllen | 0:feaa05d35ccf | 350 | |
| AlexAllen | 0:feaa05d35ccf | 351 | int SDFileSystem::_read(char *buffer, int length) { |
| AlexAllen | 0:feaa05d35ccf | 352 | _cs = 0; |
| AlexAllen | 0:feaa05d35ccf | 353 | |
| AlexAllen | 0:feaa05d35ccf | 354 | // read until start byte (0xFF) |
| AlexAllen | 0:feaa05d35ccf | 355 | while(_spi.write(0xFF) != 0xFE); |
| AlexAllen | 0:feaa05d35ccf | 356 | |
| AlexAllen | 0:feaa05d35ccf | 357 | // read data |
| AlexAllen | 0:feaa05d35ccf | 358 | for(int i=0; i<length; i++) { |
| AlexAllen | 0:feaa05d35ccf | 359 | buffer[i] = _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 360 | } |
| AlexAllen | 0:feaa05d35ccf | 361 | _spi.write(0xFF); // checksum |
| AlexAllen | 0:feaa05d35ccf | 362 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 363 | |
| AlexAllen | 0:feaa05d35ccf | 364 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 365 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 366 | return 0; |
| AlexAllen | 0:feaa05d35ccf | 367 | } |
| AlexAllen | 0:feaa05d35ccf | 368 | |
| AlexAllen | 0:feaa05d35ccf | 369 | int SDFileSystem::_write(const char *buffer, int length) { |
| AlexAllen | 0:feaa05d35ccf | 370 | _cs = 0; |
| AlexAllen | 0:feaa05d35ccf | 371 | |
| AlexAllen | 0:feaa05d35ccf | 372 | // indicate start of block |
| AlexAllen | 0:feaa05d35ccf | 373 | _spi.write(0xFE); |
| AlexAllen | 0:feaa05d35ccf | 374 | |
| AlexAllen | 0:feaa05d35ccf | 375 | // write the data |
| AlexAllen | 0:feaa05d35ccf | 376 | for(int i=0; i<length; i++) { |
| AlexAllen | 0:feaa05d35ccf | 377 | _spi.write(buffer[i]); |
| AlexAllen | 0:feaa05d35ccf | 378 | } |
| AlexAllen | 0:feaa05d35ccf | 379 | |
| AlexAllen | 0:feaa05d35ccf | 380 | // write the checksum |
| AlexAllen | 0:feaa05d35ccf | 381 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 382 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 383 | |
| AlexAllen | 0:feaa05d35ccf | 384 | // check the repsonse token |
| AlexAllen | 0:feaa05d35ccf | 385 | if((_spi.write(0xFF) & 0x1F) != 0x05) { |
| AlexAllen | 0:feaa05d35ccf | 386 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 387 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 388 | return 1; |
| AlexAllen | 0:feaa05d35ccf | 389 | } |
| AlexAllen | 0:feaa05d35ccf | 390 | |
| AlexAllen | 0:feaa05d35ccf | 391 | // wait for write to finish |
| AlexAllen | 0:feaa05d35ccf | 392 | while(_spi.write(0xFF) == 0); |
| AlexAllen | 0:feaa05d35ccf | 393 | |
| AlexAllen | 0:feaa05d35ccf | 394 | _cs = 1; |
| AlexAllen | 0:feaa05d35ccf | 395 | _spi.write(0xFF); |
| AlexAllen | 0:feaa05d35ccf | 396 | return 0; |
| AlexAllen | 0:feaa05d35ccf | 397 | } |
| AlexAllen | 0:feaa05d35ccf | 398 | |
| AlexAllen | 0:feaa05d35ccf | 399 | static int ext_bits(char *data, int msb, int lsb) { |
| AlexAllen | 0:feaa05d35ccf | 400 | int bits = 0; |
| AlexAllen | 0:feaa05d35ccf | 401 | int size = 1 + msb - lsb; |
| AlexAllen | 0:feaa05d35ccf | 402 | for(int i=0; i<size; i++) { |
| AlexAllen | 0:feaa05d35ccf | 403 | int position = lsb + i; |
| AlexAllen | 0:feaa05d35ccf | 404 | int byte = 15 - (position >> 3); |
| AlexAllen | 0:feaa05d35ccf | 405 | int bit = position & 0x7; |
| AlexAllen | 0:feaa05d35ccf | 406 | int value = (data[byte] >> bit) & 1; |
| AlexAllen | 0:feaa05d35ccf | 407 | bits |= value << i; |
| AlexAllen | 0:feaa05d35ccf | 408 | } |
| AlexAllen | 0:feaa05d35ccf | 409 | return bits; |
| AlexAllen | 0:feaa05d35ccf | 410 | } |
| AlexAllen | 0:feaa05d35ccf | 411 | |
| AlexAllen | 0:feaa05d35ccf | 412 | int SDFileSystem::_sd_sectors() { |
| AlexAllen | 0:feaa05d35ccf | 413 | |
| AlexAllen | 0:feaa05d35ccf | 414 | // CMD9, Response R2 (R1 byte + 16-byte block read) |
| AlexAllen | 0:feaa05d35ccf | 415 | if(_cmdx(9, 0) != 0) { |
| AlexAllen | 0:feaa05d35ccf | 416 | fprintf(stderr, "Didn't get a response from the disk\n"); |
| AlexAllen | 0:feaa05d35ccf | 417 | return 0; |
| AlexAllen | 0:feaa05d35ccf | 418 | } |
| AlexAllen | 0:feaa05d35ccf | 419 | |
| AlexAllen | 0:feaa05d35ccf | 420 | char csd[16]; |
| AlexAllen | 0:feaa05d35ccf | 421 | if(_read(csd, 16) != 0) { |
| AlexAllen | 0:feaa05d35ccf | 422 | fprintf(stderr, "Couldn't read csd response from disk\n"); |
| AlexAllen | 0:feaa05d35ccf | 423 | return 0; |
| AlexAllen | 0:feaa05d35ccf | 424 | } |
| AlexAllen | 0:feaa05d35ccf | 425 | |
| AlexAllen | 0:feaa05d35ccf | 426 | // csd_structure : csd[127:126] |
| AlexAllen | 0:feaa05d35ccf | 427 | // c_size : csd[73:62] |
| AlexAllen | 0:feaa05d35ccf | 428 | // c_size_mult : csd[49:47] |
| AlexAllen | 0:feaa05d35ccf | 429 | // read_bl_len : csd[83:80] - the *maximum* read block length |
| AlexAllen | 0:feaa05d35ccf | 430 | |
| AlexAllen | 0:feaa05d35ccf | 431 | int csd_structure = ext_bits(csd, 127, 126); |
| AlexAllen | 0:feaa05d35ccf | 432 | int c_size = ext_bits(csd, 73, 62); |
| AlexAllen | 0:feaa05d35ccf | 433 | int c_size_mult = ext_bits(csd, 49, 47); |
| AlexAllen | 0:feaa05d35ccf | 434 | int read_bl_len = ext_bits(csd, 83, 80); |
| AlexAllen | 0:feaa05d35ccf | 435 | |
| AlexAllen | 0:feaa05d35ccf | 436 | // printf("CSD_STRUCT = %d\n", csd_structure); |
| AlexAllen | 0:feaa05d35ccf | 437 | |
| AlexAllen | 0:feaa05d35ccf | 438 | if(csd_structure != 0) { |
| AlexAllen | 0:feaa05d35ccf | 439 | fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n"); |
| AlexAllen | 0:feaa05d35ccf | 440 | return 0; |
| AlexAllen | 0:feaa05d35ccf | 441 | } |
| AlexAllen | 0:feaa05d35ccf | 442 | |
| AlexAllen | 0:feaa05d35ccf | 443 | // memory capacity = BLOCKNR * BLOCK_LEN |
| AlexAllen | 0:feaa05d35ccf | 444 | // where |
| AlexAllen | 0:feaa05d35ccf | 445 | // BLOCKNR = (C_SIZE+1) * MULT |
| AlexAllen | 0:feaa05d35ccf | 446 | // MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8) |
| AlexAllen | 0:feaa05d35ccf | 447 | // BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12) |
| AlexAllen | 0:feaa05d35ccf | 448 | |
| AlexAllen | 0:feaa05d35ccf | 449 | int block_len = 1 << read_bl_len; |
| AlexAllen | 0:feaa05d35ccf | 450 | int mult = 1 << (c_size_mult + 2); |
| AlexAllen | 0:feaa05d35ccf | 451 | int blocknr = (c_size + 1) * mult; |
| AlexAllen | 0:feaa05d35ccf | 452 | int capacity = blocknr * block_len; |
| AlexAllen | 0:feaa05d35ccf | 453 | |
| AlexAllen | 0:feaa05d35ccf | 454 | int blocks = capacity / 512; |
| AlexAllen | 0:feaa05d35ccf | 455 | |
| AlexAllen | 0:feaa05d35ccf | 456 | return blocks; |
| AlexAllen | 0:feaa05d35ccf | 457 | } |