USBMSD SD card Hello World for Mbed platforms
Dependencies: mbed USBMSD_SD USBDevice
Diff: USBDevice/USBMSD/USB_SDcard.cpp
- Revision:
- 7:6494da2a5c60
- Parent:
- 6:126c4d980196
- Child:
- 8:534fd41d8cc7
--- a/USBDevice/USBMSD/USB_SDcard.cpp Mon Nov 14 10:00:07 2011 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,374 +0,0 @@ -/* mbed USB_SDcard Library, for accessing SD cards - * Copyright (c) 2008-2010, sford - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ - -#include "USB_SDcard.h" - -#define SD_COMMAND_TIMEOUT 5000 - -USB_SDcard::USB_SDcard(PinName mosi, PinName miso, PinName sclk, PinName cs): - _spi(mosi, miso, sclk), _cs(cs) { - _cs = 1; - USBMSD::connect(); -} - -#define R1_IDLE_STATE (1 << 0) -#define R1_ERASE_RESET (1 << 1) -#define R1_ILLEGAL_COMMAND (1 << 2) -#define R1_COM_CRC_ERROR (1 << 3) -#define R1_ERASE_SEQUENCE_ERROR (1 << 4) -#define R1_ADDRESS_ERROR (1 << 5) -#define R1_PARAMETER_ERROR (1 << 6) - -// Types -// - v1.x Standard Capacity -// - v2.x Standard Capacity -// - v2.x High Capacity -// - Not recognised as an SD Card - -#define SDCARD_FAIL 0 -#define SDCARD_V1 1 -#define SDCARD_V2 2 -#define SDCARD_V2HC 3 - -int USB_SDcard::initialise_card() { - // Set to 100kHz for initialisation, and clock card with cs = 1 - _spi.frequency(100000); - _cs = 1; - for(int i=0; i<16; i++) { - _spi.write(0xFF); - } - - // send CMD0, should return with all zeros except IDLE STATE set (bit 0) - if(_cmd(0, 0) != R1_IDLE_STATE) { - fprintf(stderr, "No disk, or could not put SD card in to SPI idle state\n"); - return SDCARD_FAIL; - } - - // send CMD8 to determine whther it is ver 2.x - int r = _cmd8(); - if(r == R1_IDLE_STATE) { - return initialise_card_v2(); - } else if(r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) { - return initialise_card_v1(); - } else { - fprintf(stderr, "Not in idle state after sending CMD8 (not an SD card?)\n"); - return SDCARD_FAIL; - } -} - -int USB_SDcard::initialise_card_v1() { - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { - _cmd(55, 0); - if(_cmd(41, 0) == 0) { - return SDCARD_V1; - } - } - - fprintf(stderr, "Timeout waiting for v1.x card\n"); - return SDCARD_FAIL; -} - -int USB_SDcard::initialise_card_v2() { - - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { - _cmd(55, 0); - if(_cmd(41, 0) == 0) { - _cmd58(); - return SDCARD_V2; - } - } - - fprintf(stderr, "Timeout waiting for v2.x card\n"); - return SDCARD_FAIL; -} - -uint32_t USB_SDcard::memorySize() -{ - return (uint32_t)capacity; -} - -uint16_t USB_SDcard::blockSize() -{ - return (uint16_t)block_len; -} - -int USB_SDcard::diskInit() { - - int i = initialise_card(); -// printf("init card = %d\n", i); -// printf("OK\n"); - - _sectors = _sd_sectors(); - - // Set block length to 512 (CMD16) - if(_cmd(16, 512) != 0) { - fprintf(stderr, "Set 512-byte block timed out\n"); - return 1; - } - - _spi.frequency(1000000); // Set to 1MHz for data transfer - return 0; -} - -int USB_SDcard::blockWrite(uint8_t * buffer, uint16_t block_number) { - // set write address for single block (CMD24) - if(_cmd(24, block_number * 512) != 0) { - return 1; - } - - // send the data block - _write((const char *)buffer, 512); - return 0; -} - -int USB_SDcard::blockRead(uint8_t * buffer, uint16_t block_number) { - // set read address for single block (CMD17) - if(_cmd(17, block_number * 512) != 0) { - return 1; - } - - // receive the data - _read((char *)buffer, 512); - return 0; -} - -int USB_SDcard::disk_status() { return 0; } -int USB_SDcard::disk_sync() { return 0; } -int USB_SDcard::disk_sectors() { return _sectors; } - -// PRIVATE FUNCTIONS - -int USB_SDcard::_cmd(int cmd, int arg) { - _cs = 0; - - // send a command - _spi.write(0x40 | cmd); - _spi.write(arg >> 24); - _spi.write(arg >> 16); - _spi.write(arg >> 8); - _spi.write(arg >> 0); - _spi.write(0x95); - - // wait for the repsonse (response[7] == 0) - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { - int response = _spi.write(0xFF); - if(!(response & 0x80)) { - _cs = 1; - _spi.write(0xFF); - return response; - } - } - _cs = 1; - _spi.write(0xFF); - return -1; // timeout -} -int USB_SDcard::_cmdx(int cmd, int arg) { - _cs = 0; - - // send a command - _spi.write(0x40 | cmd); - _spi.write(arg >> 24); - _spi.write(arg >> 16); - _spi.write(arg >> 8); - _spi.write(arg >> 0); - _spi.write(0x95); - - // wait for the repsonse (response[7] == 0) - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { - int response = _spi.write(0xFF); - if(!(response & 0x80)) { - return response; - } - } - _cs = 1; - _spi.write(0xFF); - return -1; // timeout -} - - -int USB_SDcard::_cmd58() { - _cs = 0; - int arg = 0; - - // send a command - _spi.write(0x40 | 58); - _spi.write(arg >> 24); - _spi.write(arg >> 16); - _spi.write(arg >> 8); - _spi.write(arg >> 0); - _spi.write(0x95); - - // wait for the repsonse (response[7] == 0) - for(int i=0; i<SD_COMMAND_TIMEOUT; i++) { - int response = _spi.write(0xFF); - if(!(response & 0x80)) { - int ocr = _spi.write(0xFF) << 24; - ocr |= _spi.write(0xFF) << 16; - ocr |= _spi.write(0xFF) << 8; - ocr |= _spi.write(0xFF) << 0; -// printf("OCR = 0x%08X\n", ocr); - _cs = 1; - _spi.write(0xFF); - return response; - } - } - _cs = 1; - _spi.write(0xFF); - return -1; // timeout -} - -int USB_SDcard::_cmd8() { - _cs = 0; - - // send a command - _spi.write(0x40 | 8); // CMD8 - _spi.write(0x00); // reserved - _spi.write(0x00); // reserved - _spi.write(0x01); // 3.3v - _spi.write(0xAA); // check pattern - _spi.write(0x87); // crc - - // wait for the repsonse (response[7] == 0) - for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) { - char response[5]; - response[0] = _spi.write(0xFF); - if(!(response[0] & 0x80)) { - for(int j=1; j<5; j++) { - response[i] = _spi.write(0xFF); - } - _cs = 1; - _spi.write(0xFF); - return response[0]; - } - } - _cs = 1; - _spi.write(0xFF); - return -1; // timeout -} - -int USB_SDcard::_read(char *buffer, int length) { - _cs = 0; - - // read until start byte (0xFF) - while(_spi.write(0xFF) != 0xFE); - - // read data - for(int i=0; i<length; i++) { - buffer[i] = _spi.write(0xFF); - } - _spi.write(0xFF); // checksum - _spi.write(0xFF); - - _cs = 1; - _spi.write(0xFF); - return 0; -} - -int USB_SDcard::_write(const char *buffer, int length) { - _cs = 0; - - // indicate start of block - _spi.write(0xFE); - - // write the data - for(int i=0; i<length; i++) { - _spi.write(buffer[i]); - } - - // write the checksum - _spi.write(0xFF); - _spi.write(0xFF); - - // check the repsonse token - if((_spi.write(0xFF) & 0x1F) != 0x05) { - _cs = 1; - _spi.write(0xFF); - return 1; - } - - // wait for write to finish - while(_spi.write(0xFF) == 0); - - _cs = 1; - _spi.write(0xFF); - return 0; -} - -static int ext_bits(char *data, int msb, int lsb) { - int bits = 0; - int size = 1 + msb - lsb; - for(int i=0; i<size; i++) { - int position = lsb + i; - int byte = 15 - (position >> 3); - int bit = position & 0x7; - int value = (data[byte] >> bit) & 1; - bits |= value << i; - } - return bits; -} - -int USB_SDcard::_sd_sectors() { - - // CMD9, Response R2 (R1 byte + 16-byte block read) - if(_cmdx(9, 0) != 0) { - fprintf(stderr, "Didn't get a response from the disk\n"); - return 0; - } - - char csd[16]; - if(_read(csd, 16) != 0) { - fprintf(stderr, "Couldn't read csd response from disk\n"); - return 0; - } - - // csd_structure : csd[127:126] - // c_size : csd[73:62] - // c_size_mult : csd[49:47] - // read_bl_len : csd[83:80] - the *maximum* read block length - - int csd_structure = ext_bits(csd, 127, 126); - int c_size = ext_bits(csd, 73, 62); - int c_size_mult = ext_bits(csd, 49, 47); - int read_bl_len = ext_bits(csd, 83, 80); - -// printf("CSD_STRUCT = %d\n", csd_structure); - - if(csd_structure != 0) { - fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures\n"); - return 0; - } - - // memory capacity = BLOCKNR * BLOCK_LEN - // where - // BLOCKNR = (C_SIZE+1) * MULT - // MULT = 2^(C_SIZE_MULT+2) (C_SIZE_MULT < 8) - // BLOCK_LEN = 2^READ_BL_LEN, (READ_BL_LEN < 12) - - block_len = 1 << read_bl_len; - int mult = 1 << (c_size_mult + 2); - int blocknr = (c_size + 1) * mult; - capacity = blocknr * block_len; - - int blocks = capacity / 512; - - return blocks; -}