Yes, this is a LiteOn. The OEM version of LTR-32123S. And yes, you can rev it up to 40x.
1/ Back up your current firmware! There are no publicly known copies of the X7S2 firmware, which means that if you ever want to revert, you'll have to use your backup copy. To back up your firmware, you will need MtkFlash (IIRC, this drive is old enough that you can't use LtnFW or the other Windows flashers, though I could be wrong about that). There is an extensive MtkFlash guide plus a very handy build-your-own-MtkFlash-command tool at http://dhc014.rpc1.org/howto.htm#mtkflash
2/ Please send a copy of your TDK firmware backup to dhc014
so that he could add it to his firmware archive. To send it to him, see: http://dhc014.rpc1.org/contactme.htm
3/ Now, download the XSU1
firmware. You can find it here: http://dhc014.rpc1.org/indexOEM.htm#LTR-32123S
4/ Once you have unzipped this firmware, you will need to use MtkFlash to flash your drive. Once again, please refer to the MtkFlash guide mentioned in step 1.
And that's it!...