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#include "sd.h"
#include "spi.h"
#include "util.h"
static uint8_t sd_is_block_device = 0;
uint8_t sd_send_command_util(uint8_t cmd, uint32_t data) {
uint8_t i;
uint8_t x = 0x01;
if (cmd == SD_GO_IDLE_STATE)
x = 0x95; /* CRC */
else if (cmd == SD_SEND_IF_COND)
x = 0x87; /* CRC */
cmd |= 0x40;
SD_DESELECT();
spi_tx(0xff);
SD_SELECT();
spi_tx(0xff);
spi_tx(cmd);
spi_tx((uint8_t) (data >> 24));
spi_tx((uint8_t) (data >> 16));
spi_tx((uint8_t) (data >> 8));
spi_tx((uint8_t) (data));
spi_tx(x);
i = 10;
do {
x = spi_rx();
} while ((x & 0x80) && --i);
return x;
}
uint8_t sd_send_command(uint8_t cmd, uint32_t data) {
if (cmd & 0x80) {
uint8_t res = sd_send_command_util(SD_APP_CMD, 0);
if (res > 1)
return res;
cmd &= 0x7f;
}
return sd_send_command_util(cmd, data);
}
void sd_wait(void) {
uint8_t resp;
uint8_t i = 255;
do {
resp = sd_send_command(SD_SEND_OP_COND, 0);
} while (resp != 0 && --i);
}
char sd_init(void) {
uint8_t i;
uint16_t tmr;
spi_init();
SD_CHIP_SELECT_TRIS = 0;
SD_SELECT();
for (i = 10; i; i--)
delay_100us();
SD_DESELECT();
for (i = 0; i < 20; i++)
spi_tx(0xff);
SD_SELECT();
tmr = 1000;
do {
for (i = 10; i; i--)
delay_100us();
i = sd_send_command(SD_GO_IDLE_STATE, 0);
} while (--tmr && i != 1);
if (sd_send_command(SD_SEND_IF_COND, 0x1aa) == 1) {
/* SD v2 */
uint8_t ocr[4];
ocr[0] = spi_rx();
ocr[1] = spi_rx();
ocr[2] = spi_rx();
ocr[3] = spi_rx();
#ifdef DEBUG
printf("SD v2 %x:%x:%x:%x\r\n", ocr[0], ocr[1], ocr[2], ocr[3]);
#endif
if (ocr[2] == 0x01 && ocr[3] == 0xaa) {
tmr = 10000;
do {
delay_100us();
i = sd_send_command(SD_OP_COND_SDC, 1UL << 30);
} while (--tmr && i);
#ifdef DEBUG
printf("Done %u %u\r\n", tmr, i);
#endif
i = sd_send_command(SD_READ_OCR, 0);
if (tmr && i == 0) {
ocr[0] = spi_rx();
ocr[1] = spi_rx();
ocr[2] = spi_rx();
ocr[3] = spi_rx();
#ifdef DEBUG
printf("OCR: %x:%x:%x:%x\r\n", ocr[0], ocr[1], ocr[2], ocr[3]);
#endif
if (ocr[0] & 0x40)
sd_is_block_device = 1;
}
}
} else {
/* SD v1 */
#ifdef DEBUG
printf("SD v1\r\n");
#endif
}
SD_DESELECT();
spi_rx();
return 0;
}
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