uint8_t sd_read_block(uint32_t block_offset, uint8_t block[512]) {
int r;
uint16_t i;
if(sd_channel==1)
sd_select(1);
else
sd_select(0);
if (sd_type == SD_TYPE_SDHC) {
r = sd_cmd(CMD_READ_SINGLE_BLOCK, block_offset);
} else {
r = sd_cmd(CMD_READ_SINGLE_BLOCK, block_offset << 9);
}
if (r != 0) {
uart_puts("CMD_READ_SINGLE_BLOCK command failed for offset");
uart_puthex32(block_offset);
uart_puts("\r\n");
if(sd_channel == 1)
sd_deselect(1);
else
sd_deselect(0);
sdok = 0;
return r;
}
while (sd_recv() != 0xfe); // TODO: use timeout?
//UART_TxStr("Block:\r\n");
for (i = 0; i < 512; i++) {
uint8_t c = sd_recv();
block[i] = c;
//UART_TxUint8(c);
}
//UART_TxStr("\r\n");
sd_recv(); sd_recv(); // skip CRC
if(sd_channel == 1)
sd_deselect(1);
else
sd_deselect(0);
sd_recv();
return 0;
}
int sd_init(void)
{
int err;
fd = ios_open("/dev/sdio/slot0", 0);
if (fd < 0)
return fd;
err = sd_reset_card();
if (err) {
goto out;
}
// now in standby state
err = sd_select();
if (err)
goto out;
// now in transfer state
// Some broken cards require this:
err = sd_set_blocklength(0x200);
if (err)
goto out;
err = sd_set_bus_width(4); // XXX: Should check in SCR first.
if (err)
goto out;
err = sd_set_clock(); // XXX: Should check.
if (err)
goto out;
return 0;
out:
sd_close();
return err;
}
int sd_init() {
uint8_t i;
int k;
uint8_t r;
uint8_t mmc = 0;
sdok = 0;
sd_deselect();
/* 74 cycles to start up the card */
for (i = 0; i < 10; i++) {
sd_recv();
}
sd_select();
/* enter idle mode */
for (k = 0; ; k++) {
r = sd_cmd(CMD_GO_IDLE_STATE, 0);
if (r == (1 << R1_IDLE_STATE)) {
uart_puts("sd: entered IDLE state\r\n");
break;
}
if (k == 0x1ff) {
uart_puts("sd: failed to enter IDLE state\r\n");
break;
//sd_deselect();
//return 0;
}
}
/* check SD card specification version */
char sdhc = 0;
r = sd_cmd(CMD_SEND_IF_COND, 0x100 | 0xaa); /* 2.7V..3.6V */
if ((r & (1 << R1_ILL_COMMAND)) == 0) {
uart_puts("sd: SD SPEC 2 (or SDHC)\r\n");
//sd_type = SD_TYPE_SPEC2;
sd_type = SD_TYPE_SPEC2;
sdhc = 1;
sd_recv();
sd_recv();
r = sd_recv();
if (r & 1 == 0) {
uart_puts("sd: voltage range mismatch\r\n");
}
r = sd_recv();
if (r != 0xaa) {
uart_puts("sd: wrong test pattern\r\n");
}
} else {
sd_cmd(CMD_APP, 0);
r = sd_cmd(CMD_SD_SEND_OP_COND, 0);
if ((r & (1 << R1_ILL_COMMAND)) == 0) {
uart_puts("sd: SD SPEC 1\r\n");
sdhc = 0;
sd_type = SD_TYPE_SPEC1;
} else {
uart_puts("sd: MMC\r\n");
mmc = 1;
sd_type = SD_TYPE_MMC;
}
}
uart_puts("sd: wait for card to get ready\r\n");
/* wait for the card to get ready */
for (k = 0; ; k++) {
if (sd_type == SD_TYPE_SPEC1 || sd_type == SD_TYPE_SPEC2) { // if not mmc
uint32_t arg = 0;
if (sd_type == SD_TYPE_SPEC2) {
arg = 0x40000000;
}
sd_cmd(CMD_APP, 0);
r = sd_cmd(CMD_SD_SEND_OP_COND, arg);
} else {
r = sd_cmd(CMD_SEND_OP_COND, 0);
}
if ((r & (1 << R1_IDLE_STATE)) == 0) {
uart_puts("sd: entered IDLE state (ready)\r\n");
break;
}
if (k == 0x7fff) {
uart_puts("sd: card didn't enter IDLE state (not ready)\r\n");
//sd_deselect();
//return 1;
break;
}
}
if (sd_type == SD_TYPE_SPEC2) {
r = sd_cmd(CMD_READ_OCR, 0);
if (r) {
uart_puts("sd: OCR command failed\r\n");
sd_deselect();
return 1;
} else {
if (sd_recv() & 0x40) {
uart_puts("sd: card mode - SDHC\r\n");
sd_type = SD_TYPE_SDHC;
}
sd_recv();
sd_recv();
sd_recv();
}
}
if (sd_cmd(CMD_SET_BLOCKLEN, 512) != 0) {
uart_puts("sd: failed to set block length to 512 bytes\r\n");
sd_deselect();
return 1;
}
uart_puts("sd: done\r\n");
sd_deselect();
sdok = 1;
return 0;
}
