Thank’s for the answer, i’ve find the solution for i2cdetect issue, it’s been because i’m in 3.18 kernel so I’ve modified config.txt to activate i2c !
Now i have another problem, the pin of my backplat is different than the normal configuration. I’ve found a modified hd44780 driver with the right pin out conf but I dont know how to put the hd44780-i2c.c files in lcdproc.
In usr/lib i dont have any lcdproc folder to put the files in.