On Thu, 24 Jun 2010 19:49:00 +0200, Giampaolo Bellini wrote: > Hello Jean > > thanks you so much for your time! > > > This means they refer to left-aligned addresses. Linux uses > > right-aligned addresses, so your device lives at 0x20 as far as Linux > > is concerned. > > effectively, after hours and hours of testing, I found by myself that > the correct addressed where 0x20 and 0x21 but was not able to Just 0x20, not "0x20 and 0x21". The "address byte" that goes on the wire is made of 7 bits of address and 1 bit of direction (read or write). 0x40 is (0x20 << 1) | 0, 0x41 is (0x20 << 1) | 1. > understand why the manufacturer gives me what I think was a wrong > registers map ! These are device addresses, nothing to do with a "register map". > > Check arch/arm/mach-ks8695/board-acs5k.c and > > arch/arm/mach-pxa/cm-x300.c for examples. > > I'll check these source in the next days... so pca953x driver could > just export his services to other modules ? does it nothing alone > and/or paired with gpiolib ? or it's just a question of give the > pca953x some platforms data ? It is indeed just a question of instantiating the pca953x device with some platform data. > > (Assuming i2c-0 is the bus on which the chip actually lives - you can > > check with i2cdetect). That being said, I doubt that a GPIO chip can > > really be instantiated from user-space, as it needs configuration > > settings which you can't provide that way. > > you are right... i've try yesterday with the correct addresses but > with no success. -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
