I only have those options available:
root@mediahub:~# blkdiscard --help
Usage:
blkdiscard [options] <device>
Discard the content of sectors on a device.
Options:
-o, --offset <num> offset in bytes to discard from
-l, --length <num> length of bytes to discard from the offset
-p, --step <num> size of the discard iterations within the offset
-s, --secure perform secure discard
-z, --zeroout zero-fill rather than discard
-v, --verbose print aligned length and offset
-h, --help display this help
-V, --version display version
For more details see blkdiscard(8).