mirror of
https://github.com/wiiu-env/libfat.git
synced 2024-11-30 05:34:18 +01:00
211 lines
6.1 KiB
C
211 lines
6.1 KiB
C
/*
|
|
io_sd_common.c
|
|
|
|
By chishm (Michael Chisholm)
|
|
|
|
Common SD card routines
|
|
|
|
SD routines partially based on sd.s by Romman
|
|
|
|
Copyright (c) 2006 Michael "Chishm" Chisholm
|
|
|
|
Redistribution and use in source and binary forms, with or without modification,
|
|
are permitted provided that the following conditions are met:
|
|
|
|
1. Redistributions of source code must retain the above copyright notice,
|
|
this list of conditions and the following disclaimer.
|
|
2. Redistributions in binary form must reproduce the above copyright notice,
|
|
this list of conditions and the following disclaimer in the documentation and/or
|
|
other materials provided with the distribution.
|
|
3. The name of the author may not be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
|
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
|
|
AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
|
|
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
2006-08-07 - Chishm
|
|
* Moved the SD initialization to a common function
|
|
* Increased timeouts for slower cards
|
|
|
|
2006-08-08 - Chishm
|
|
* Init aborts when it doesn't get a valid response to APP_CMD - speeds up detection when no card is inserted
|
|
*/
|
|
|
|
#include "io_sd_common.h"
|
|
|
|
#define MAX_STARTUP_TRIES 1000 // Arbitrary value, check if the card is ready 20 times before giving up
|
|
#define RESPONSE_TIMEOUT 256 // Number of clocks sent to the SD card before giving up
|
|
|
|
/*
|
|
Improved CRC7 function provided by cory1492
|
|
Calculates the CRC of an SD command, and includes the end bit in the byte
|
|
*/
|
|
u8 _SD_CRC7(u8* data, int cnt) {
|
|
int i, a;
|
|
u8 crc, temp;
|
|
|
|
crc = 0;
|
|
for (a = 0; a < cnt; a++)
|
|
{
|
|
temp = data[a];
|
|
for (i = 0; i < 8; i++)
|
|
{
|
|
crc <<= 1;
|
|
if ((temp & 0x80) ^ (crc & 0x80)) crc ^= 0x09;
|
|
temp <<= 1;
|
|
}
|
|
}
|
|
crc = (crc << 1) | 1;
|
|
return(crc);
|
|
}
|
|
|
|
/*
|
|
Calculates the CRC16 for a sector of data. Calculates it
|
|
as 4 separate lots, merged into one buffer. This is used
|
|
for 4 SD data lines, not for 1 data line alone.
|
|
*/
|
|
void _SD_CRC16 (u8* buff, int buffLength, u8* crc16buff) {
|
|
u32 a, b, c, d;
|
|
int count;
|
|
u32 bitPattern = 0x80808080; // r7
|
|
u32 crcConst = 0x1021; // r8
|
|
u32 dataByte = 0; // r2
|
|
|
|
a = 0; // r3
|
|
b = 0; // r4
|
|
c = 0; // r5
|
|
d = 0; // r6
|
|
|
|
buffLength = buffLength * 8;
|
|
|
|
|
|
do {
|
|
if (bitPattern & 0x80) dataByte = *buff++;
|
|
|
|
a = a << 1;
|
|
if ( a & 0x10000) a ^= crcConst;
|
|
if (dataByte & (bitPattern >> 24)) a ^= crcConst;
|
|
|
|
b = b << 1;
|
|
if (b & 0x10000) b ^= crcConst;
|
|
if (dataByte & (bitPattern >> 25)) b ^= crcConst;
|
|
|
|
c = c << 1;
|
|
if (c & 0x10000) c ^= crcConst;
|
|
if (dataByte & (bitPattern >> 26)) c ^= crcConst;
|
|
|
|
d = d << 1;
|
|
if (d & 0x10000) d ^= crcConst;
|
|
if (dataByte & (bitPattern >> 27)) d ^= crcConst;
|
|
|
|
bitPattern = (bitPattern >> 4) | (bitPattern << 28);
|
|
} while (buffLength-=4);
|
|
|
|
count = 16; // r8
|
|
|
|
do {
|
|
bitPattern = bitPattern << 4;
|
|
if (a & 0x8000) bitPattern |= 8;
|
|
if (b & 0x8000) bitPattern |= 4;
|
|
if (c & 0x8000) bitPattern |= 2;
|
|
if (d & 0x8000) bitPattern |= 1;
|
|
|
|
a = a << 1;
|
|
b = b << 1;
|
|
c = c << 1;
|
|
d = d << 1;
|
|
|
|
count--;
|
|
|
|
if (!(count & 0x01)) {
|
|
*crc16buff++ = (u8)(bitPattern & 0xff);
|
|
}
|
|
} while (count != 0);
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
Initialise the SD card, after it has been sent into an Idle state
|
|
cmd_6byte_response: a pointer to a function that sends the SD card a command and gets a 6 byte response
|
|
cmd_17byte_response: a pointer to a function that sends the SD card a command and gets a 17 byte response
|
|
use4bitBus: initialise card to use a 4 bit data bus when communicating with the card
|
|
RCA: a pointer to the location to store the card's Relative Card Address, preshifted up by 16 bits.
|
|
*/
|
|
bool _SD_InitCard (_SD_FN_CMD_6BYTE_RESPONSE cmd_6byte_response,
|
|
_SD_FN_CMD_17BYTE_RESPONSE cmd_17byte_response,
|
|
bool use4bitBus,
|
|
u32 *RCA)
|
|
{
|
|
u8 responseBuffer[17] = {0};
|
|
int i;
|
|
|
|
for (i = 0; i < MAX_STARTUP_TRIES ; i++) {
|
|
cmd_6byte_response (responseBuffer, APP_CMD, 0);
|
|
// Check that the card gave the correct response
|
|
if (responseBuffer[0] != APP_CMD) {
|
|
return false;
|
|
}
|
|
if (
|
|
cmd_6byte_response (responseBuffer, SD_APP_OP_COND, SD_OCR_VALUE) &&
|
|
((responseBuffer[1] & 0x80) != 0))
|
|
{
|
|
// Card is ready to receive commands now
|
|
break;
|
|
}
|
|
}
|
|
if (i >= MAX_STARTUP_TRIES) {
|
|
return false;
|
|
}
|
|
|
|
// The card's name, as assigned by the manufacturer
|
|
cmd_17byte_response (responseBuffer, ALL_SEND_CID, 0);
|
|
|
|
// Get a new address
|
|
for (i = 0; i < MAX_STARTUP_TRIES ; i++) {
|
|
cmd_6byte_response (responseBuffer, SEND_RELATIVE_ADDR, 0);
|
|
*RCA = (responseBuffer[1] << 24) | (responseBuffer[2] << 16);
|
|
if ((responseBuffer[3] & 0x1e) != (SD_STATE_STBY << 1)) {
|
|
break;
|
|
}
|
|
}
|
|
if (i >= MAX_STARTUP_TRIES) {
|
|
return false;
|
|
}
|
|
|
|
// Some cards won't go to higher speeds unless they think you checked their capabilities
|
|
cmd_17byte_response (responseBuffer, SEND_CSD, *RCA);
|
|
|
|
// Only this card should respond to all future commands
|
|
cmd_6byte_response (responseBuffer, SELECT_CARD, *RCA);
|
|
|
|
if (use4bitBus) {
|
|
// Set a 4 bit data bus
|
|
cmd_6byte_response (responseBuffer, APP_CMD, *RCA);
|
|
cmd_6byte_response (responseBuffer, SET_BUS_WIDTH, 2); // 4-bit mode.
|
|
}
|
|
|
|
// Use 512 byte blocks
|
|
cmd_6byte_response (responseBuffer, SET_BLOCKLEN, 512); // 512 byte blocks
|
|
|
|
// Wait until card is ready for data
|
|
i = 0;
|
|
do {
|
|
if (i >= RESPONSE_TIMEOUT) {
|
|
return false;
|
|
}
|
|
i++;
|
|
} while (!cmd_6byte_response (responseBuffer, SEND_STATUS, *RCA) && ((responseBuffer[3] & 0x1f) != ((SD_STATE_TRAN << 1) | READY_FOR_DATA)));
|
|
|
|
return true;
|
|
}
|
|
|
|
|