If someone are still working on this, I would like to assist since I try to achieve the same goal.
I used the sources code here https://github.com/hisilicon/x5hd2-drivers/tree/master/source/msp/drv/frontend/tuner/tda18250b
that seems have the same base as the source from Madsion above.
The codes are very useful to understand what going on but my undrestanding in the matter of electronics are limited.
I provided some logs. All useful information are intmbslTDA18250A.c
"function tmbslTDA18250A_Open line 366", the lines number will not match with the origin source cause I have add some lines.
"<0x60[0x0] 0x0000c7", means "<"= result fro read at i2c address 0x60 and registry at 0x0 has return 0xc7
">0x60[0x25] 0x0000cb", ">"= write at i2c address 0x60 and registry at 0x25 the value 0xcb
The channels scan have been made with dvbv5-scan with fr-all file from dvb-t and fr-noos-numericable for dvb-c.
The issue that I have is I can't get any signal despite of the execution code seems to happen normally.
I tried the Madison code, it have some specific code for tda18250b but always no locked signal.
Logs provide and the function to set the frequency are different.
The sources code have some specifics parameter, as IF, that I have to find but without a possibility to "sniff" the communication between the xbox an the device I tried to "brute force " it.
I have found that 550000 Hz, 50000 Hz can lock dvb-t signal and 495000 Hz a dvb-c signal. Not sure if there are a good one's or noises.
There are some parameter, as AGC and some filters than I can undestand so I am stuck.