115 lines
2.6 KiB
C
115 lines
2.6 KiB
C
|
#include <stdio.h>
|
||
|
|
#include "sdc.h"
|
||
|
|
|
||
|
|
void sdc_init(SDC *sdc)
|
||
|
|
{
|
||
|
|
sdc->selected = false;
|
||
|
|
sdc->initstat = 0;
|
||
|
|
sdc->recvidx = 0;
|
||
|
|
sdc->sendidx = -1;
|
||
|
|
sdc->resp = 0xff;
|
||
|
|
}
|
||
|
|
|
||
|
|
void sdc_cslow(SDC *sdc)
|
||
|
|
{
|
||
|
|
sdc->selected = true;
|
||
|
|
}
|
||
|
|
|
||
|
|
void sdc_cshigh(SDC *sdc)
|
||
|
|
{
|
||
|
|
sdc->selected = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
void sdc_spi_wr(SDC *sdc, uint8_t val)
|
||
|
|
{
|
||
|
|
if (!sdc->selected) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
sdc->resp = 0xff;
|
||
|
|
if (sdc->initstat < 8) {
|
||
|
|
// not woken yet.
|
||
|
|
sdc->initstat++;
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (sdc->sendidx >= 0) {
|
||
|
|
sdc->resp = sdc->sendbuf[sdc->sendidx++];
|
||
|
|
if (sdc->sendidx == 5) {
|
||
|
|
sdc->sendidx = -1;
|
||
|
|
}
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if ((sdc->recvidx == 0) && ((val > 0x7f) || (val < 0x40))) {
|
||
|
|
// not a command
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
sdc->recvbuf[sdc->recvidx++] = val;
|
||
|
|
if (sdc->recvidx < 6) {
|
||
|
|
// incomplete command
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
// Command complete
|
||
|
|
val &= 0x3f;
|
||
|
|
sdc->recvidx = 0;
|
||
|
|
uint8_t *b = sdc->recvbuf;
|
||
|
|
fprintf(stderr, "cmd %02x %02x %02x %02x %02x\n", b[0], b[1], b[2], b[3], b[4]);
|
||
|
|
uint8_t cmd = b[0] & 0x3f;
|
||
|
|
if (sdc->initstat == 8) {
|
||
|
|
// At this stage, we're expecting CMD0
|
||
|
|
if (cmd == 0) {
|
||
|
|
sdc->initstat++;
|
||
|
|
sdc->sendbuf[4] = 0x01;
|
||
|
|
sdc->sendidx = 4;
|
||
|
|
}
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (sdc->initstat == 9) {
|
||
|
|
// At this stage, we're expecting CMD8 with 0x1aa arg2
|
||
|
|
if ((cmd == 8) && (b[3] == 0x01) && (b[4] == 0xaa)) {
|
||
|
|
sdc->initstat++;
|
||
|
|
sdc->sendbuf[0] = 0x01;
|
||
|
|
sdc->sendbuf[1] = 0;
|
||
|
|
sdc->sendbuf[2] = 0;
|
||
|
|
sdc->sendbuf[3] = 0x01;
|
||
|
|
sdc->sendbuf[4] = 0xaa;
|
||
|
|
sdc->sendidx = 0;
|
||
|
|
} else {
|
||
|
|
sdc-> initstat = 8;
|
||
|
|
}
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (sdc->initstat == 10) {
|
||
|
|
// At this stage, we're expecting CMD55
|
||
|
|
if (cmd == 55) {
|
||
|
|
sdc->initstat++;
|
||
|
|
sdc->sendbuf[4] = 0x01;
|
||
|
|
sdc->sendidx = 4;
|
||
|
|
} else {
|
||
|
|
sdc->initstat = 8;
|
||
|
|
}
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (sdc->initstat == 11) {
|
||
|
|
// At this stage, we're expecting CMD41
|
||
|
|
if ((cmd == 41) && (b[1] == 0x40) && (b[2] == 0x00)) {
|
||
|
|
sdc->initstat++;
|
||
|
|
sdc->sendbuf[4] = 0x00;
|
||
|
|
sdc->sendidx = 4;
|
||
|
|
} else {
|
||
|
|
sdc->initstat = 8;
|
||
|
|
}
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
// We have a fully initialized card.
|
||
|
|
// Simulate success for any unknown command.
|
||
|
|
sdc->sendbuf[4] = 0x00;
|
||
|
|
sdc->sendidx = 4;
|
||
|
|
}
|
||
|
|
|
||
|
|
uint8_t sdc_spi_rd(SDC *sdc)
|
||
|
|
{
|
||
|
|
if (!sdc->selected) {
|
||
|
|
return 0xff;
|
||
|
|
}
|
||
|
|
return sdc->resp;
|
||
|
|
}
|