/** @brief Initialize a disk.
@param bVolNum The volume number of the volume whose block device is being
initialized.
@param mode The open mode, indicating the type of access required.
@return A negated ::REDSTATUS code indicating the operation result.
@retval 0 Operation was successful.
@retval -RED_EIO A disk I/O error occurred.
@retval -RED_EROFS The device is read-only media and write access was
requested.
*/
static REDSTATUS DiskOpen(
uint8_t bVolNum,
BDEVOPENMODE mode)
{
REDSTATUS ret = 0;
uint32_t ulTries;
Ctrl_status cs;
/* Note: Assuming the volume number is the same as the SD card slot. The
ASF SD/MMC driver supports two SD slots. This implementation will need
to be modified if multiple volumes share a single SD card.
*/
/* The first time the disk is opened, the SD card can take a while to get
ready, in which time sd_mmc_test_unit_ready() returns either CTRL_BUSY
or CTRL_NO_PRESENT. Try numerous times, waiting half a second after
each failure. Empirically, this has been observed to succeed on the
second try, so trying 10x more than that provides a margin of error.
*/
for(ulTries = 0U; ulTries < 20U; ulTries++) {
cs = sd_mmc_test_unit_ready(bVolNum);
if((cs != CTRL_NO_PRESENT) && (cs != CTRL_BUSY)) {
break;
}
vTaskDelay(500U / portTICK_PERIOD_MS);
}
if(cs == CTRL_GOOD) {
#if REDCONF_READ_ONLY == 0
if(mode != BDEV_O_RDONLY) {
if(sd_mmc_wr_protect(bVolNum)) {
ret = -RED_EROFS;
}
}
if(ret == 0)
#endif
{
uint32_t ulSectorLast;
(void)sd_mmc_read_capacity(bVolNum, &ulSectorLast);
/* The ASF SD/MMC driver only supports 512-byte sectors.
*/
if( (gaRedVolConf[bVolNum].ulSectorSize != 512U)
|| (((uint64_t)ulSectorLast + 1U) < gaRedVolConf[bVolNum].ullSectorCount)) {
ret = -RED_EINVAL;
}
}
} else {
ret = -RED_EIO;
}
return ret;
}
Ctrl_status sd_mmc_read_capacity_1(uint32_t *nb_sector)
{
return sd_mmc_read_capacity(1, nb_sector);
}
