After all the tests of this week, the situation is that ifup gives me can0, but I don’t see it in ifconfig, so the result is always can0 not found: which could be the problem if can0 is configured?
I also see:
Could it be a library issue?
Anyway I think that it’s not a problem of SPI, since on the oscilloscope I can see the signal SPI Slave 
also if SPI clock is always 0V. What does could be it mean? please 