Eli Hughes
test
Diff: chan_fs/diskio.c
- Revision:
- 1:68378811b1e2
- Parent:
- 0:c1253c12d4bc
--- a/chan_fs/diskio.c Sun Feb 21 02:45:09 2010 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,300 +0,0 @@
-/*-----------------------------------------------------------------------*/
-/* Low level disk I/O module skeleton for FatFs (C)ChaN, 2007 */
-/*-----------------------------------------------------------------------*/
-/* This is a stub disk I/O module that acts as front end of the existing */
-/* disk I/O modules and attach it to FatFs module with common interface. */
-/*-----------------------------------------------------------------------*/
-
-#include "diskio.h"
-#include "mbed.h"
-
-
-//******************************************************************************************************************
-// MBED SPI/CS Select functions.... Modify for your layout.
-//**************************************************************************************
-
-SPI _spi(p5, p6, p7); // mosi, miso, sclk
-DigitalOut _cs(p8);
-
-//******************************************************************************************************************
-// Low Level Sector Access Function Prototypes('C' Castrated versions of Simon Ford's C++ MBED SDFileSystem class
-//******************************************************************************************************************
-int _cmd(int cmd, int arg);
-int _read(BYTE *buffer, int length);
-int _write(BYTE *buffer, int length);
-int ext_bits(BYTE *data, int msb, int lsb);
-int _sd_sectors();
-int _sectors;
-
-#define SD_COMMAND_TIMEOUT 5000
-
-
-//******************************************************************************************************************
-// Sector Access functions for CHAN FatFs
-//******************************************************************************************************************
-
-DRESULT disk_ioctl (
- BYTE drv, /* Physical drive nmuber (0..) */
- BYTE ctrl, /* Control code */
- void *buff /* Buffer to send/receive control data */
-)
-{
- DRESULT res;
-
- switch(ctrl)
- {
- case CTRL_SYNC:
- res = RES_OK;
- break;
-
- case GET_SECTOR_SIZE:
- res = RES_OK;
- *(WORD *)buff = 512;
- break;
-
- case GET_SECTOR_COUNT:
- res = RES_OK;
- *(DWORD *)buff = (WORD)_sd_sectors();
- break;
-
- case GET_BLOCK_SIZE:
- res = RES_OK;
- *(DWORD *)buff = 1;
- break;
-
- default:
- res = RES_OK;
- break;
- }
- return res;
-}
-
-DSTATUS disk_initialize(BYTE Drive) {
-
- _spi.frequency(100000); // Set to 100kHz for initialisation
-
- // Initialise the card by clocking it a bit (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) != 0x01) {
- fprintf(stderr, "Not in idle state\n");
- return STA_NOINIT;
- }
-
- // ACMD41 to give host capacity support (repeat until not busy)
- // ACMD41 is application specific command, so we send APP_CMD (CMD55) beforehand
- for(int i=0;; i++) {
- _cmd(55, 0);
- int response = _cmd(41, 0);
- if(response == 0) {
- break;
- } else if(i > SD_COMMAND_TIMEOUT) {
- fprintf(stderr, "Timeout waiting for card\n");
- return STA_NOINIT;
- }
- }
-
- _sectors = _sd_sectors();
-
- // Set block length to 512 (CMD16)
- if(_cmd(16, 512) != 0) {
- fprintf(stderr, "Set block timeout\n");
- return STA_NOINIT;
- }
-
- _spi.frequency(10000000); // Set to 10MHz for data transfer
- return 0;
-}
-
-DRESULT disk_write(BYTE Drive,const BYTE * Buffer, DWORD SectorNumber, BYTE SectorCount)
-{
- BYTE i;
-
- BYTE * MyBufOut = (BYTE *)Buffer;
-
- for(i=0;i<SectorCount;i++)
- {
- // set write address for single block (CMD24)
- if(_cmd(24, (SectorNumber + i) * 512 ) != 0) {
- return RES_ERROR;
- }
-
- // send the data block
- _write(MyBufOut, 512);
-
- MyBufOut+=512;
- }
- return RES_OK;
-}
-
-DRESULT disk_read(BYTE Drive, BYTE * Buffer,DWORD SectorNumber, BYTE SectorCount)
-{
- BYTE i;
- for(i=0;i<SectorCount;i++)
- {
- // set read address for single block (CMD17)
- if(_cmd(17, (SectorNumber+i) * 512) != 0)
- {
- return RES_ERROR;
- }
- // receive the data
- _read(Buffer, 512);
-
- Buffer+=512;
- }
- return RES_OK;
-}
-
-
-DWORD get_fattime(void)
-{
- time_t CurrentTimeStamp;
- tm *CurrentLocalTime;
- DWORD FATFSTimeCode;
-
- CurrentTimeStamp = time(NULL);
- CurrentLocalTime = localtime(&CurrentTimeStamp);
-
- //Map the tm struct time into the FatFs time code
- FATFSTimeCode = ((CurrentLocalTime->tm_year-80)<<25) |
- ((CurrentLocalTime->tm_mon+1)<<21) |
- ((CurrentLocalTime->tm_mday)<<16) |
- ((CurrentLocalTime->tm_hour)<<11) |
- ((CurrentLocalTime->tm_min)<<5) |
- ((CurrentLocalTime->tm_sec));
-
- return FATFSTimeCode;
-}
-
-DSTATUS disk_status(BYTE Drive)
-{
- return 0;
-}
-
-//**************************************************************************************
-// Low Level Sector Access Functions (Castrated versions of Simon Fords C++ MBED class
-//**************************************************************************************
-
-int _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;
- return response;
- }
- }
- _cs = 1;
- return -1; // timeout
-}
-
-int _read(BYTE *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;
- return 0;
-}
-
-int _write(BYTE *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;
- return 1;
- }
-
- // wait for write to finish
- while(_spi.write(0xFF) == 0);
-
- _cs = 1;
- return 0;
-}
-
-int ext_bits(BYTE *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 _sd_sectors() {
-
- // CMD9, Response R2 (R1 byte + 16-byte block read)
- if(_cmd(9, 0) != 0) {
- fprintf(stderr, "Didn't get a response from the disk\n");
- return 0;
- }
-
- BYTE 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]
-
- 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);
-
- if(csd_structure != 0) {
- fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures");
- return 0;
- }
-
- int blocks = (c_size + 1) * (1 << (c_size_mult + 2));
- int block_size = 1 << read_bl_len;
-
- if(block_size != 512) {
- fprintf(stderr, "This disk tastes funny! I only like 512 byte blocks (%d)\r\n",block_size);
- return 0;
- }
-
- return blocks;
-}