int mmc_readsector(uint32_t lba, uint8_t *buffer)
{
uint16_t i,retval;
printf("\nreadsector\n");
// send read command and logical sector address
mmc_send_command(17,(lba>>7) & 0xffff, (lba<<9) & 0xffff);
//mmc_send_command(17,(lba>>16) & 0xffff, (lba) & 0xffff); //wjr
retval=mmc_get();
printf("\ngot rc %d\n",retval);
if (mmc_datatoken() != 0xfe) // if no valid token
{
mmc_clock_and_release(); // cleanup and
return -1; // return error code
}
spiReceiveN(buffer,512);
// for (i=0;i<512;i++) // read sector data
// *buffer++ = spixfer(0xff);
(void)spixfer(0xff); // ignore dummy checksum
(void)spixfer(0xff); // ignore dummy checksum
mmc_clock_and_release(); // cleanup
return 0; // return success
}
/* write a single 512 byte sector to the SD card */
unsigned int mmc_writesector(uint32_t lba, uint8_t *buffer)
{
uint16_t i;
uint8_t r;
CS_ASSERT;
// send command and sector
mmc_send_command(WRITE_SINGLE_BLOCK, lba<<9);
mmc_datatoken(); // get response
spi_byte(0xfe); // send start block token
for (i=0;i<512;i++) // write sector data
spi_byte(*buffer++);
spi_byte(0xff); // ignore checksum
spi_byte(0xff); // ignore checksum
r = spi_byte(0xff);
// check for error
if ((r & 0x1f) != 0x05) return r;
// wait for SD card to complete writing and become idle
i = 0xffff;
while (!spi_byte(0xff) && --i) ; // wait for card to finish writing
mmc_release(); // cleanup
if (!i) return -1; // timeout error
return 0;
}
/** Read MMC/SD sector.
Read a single 512 byte sector from the MMC/SD card
\param lba Logical sectornumber to read
\param buffer Pointer to buffer for received data
\return 0 on success, -1 on error
*/
int mmc_readsector(uint32_t lba, uint8_t *buffer)
{
uint16_t i;
// send read command and logical sector address
mmc_send_command(17,(lba>>7) & 0xffff, (lba<<9) & 0xffff);
if (mmc_datatoken() != 0xfe) // if no valid token
{
mmc_clock_and_release(); // cleanup and
return -1; // return error code
}
for (i=0;i<512;i++) // read sector data
*buffer++ = spi_byte(0xff);
spi_byte(0xff); // ignore dummy checksum
spi_byte(0xff); // ignore dummy checksum
mmc_clock_and_release(); // cleanup
return 0; // return success
}
/* reads a single 512 bytes sector from the SD card */
int mmc_readsector(uint32_t lba, uint8_t *buffer)
{
uint16_t i;
// send command and sector
mmc_send_command(READ_SINGLE_BLOCK, lba<<9);
if (mmc_datatoken() != 0xfe) // wait for start of block token
{
mmc_release(); // error
return -1;
}
for (i=0;i<512;i++)
*buffer++ = spi_byte(0xff); // read data
spi_byte(0xff); // ignore checksum
spi_byte(0xff); // ignore checksum
mmc_release();
return 0;
}
