Juerg Haefliger wrote: > Hi all, > > I was playing around with adding support for the sch311x to the > dme1737 driver but I'm not so sure anymore how to go about it. For > those unfamiliar with the 2 chips, both chips implement the same > (almost but very close) HW monitoring capabilities but the dme1737 > only allows access via SMBus while the sch311x only supports the LPC > interface. There are multiple ways to go about this: > > 1) 2 separate drivers. An i2c driver for the dme1737 and a platform > driver for the sch311x. They would only differ in the way they access > the HW, all the rest would be identical and could be shared. > > 2) 1 single driver that either registers itself as an i2c client or a > platform driver, depending on which chip is detected. > > 3) 1 single driver that registers itself as an i2c client independent > of the chip found. > > While option 1) would be preferred, I kind of shy away from the amount > of work/changes necessary to implement it. I started of with option 2) > but it turned out to be bigger than expected. Lots of code for > registering/adding the platform stuff to support a chip that doesn't > seem to be very popular. It blows up the code and makes it pretty > ugly. I'm almost tempted to go with option 1)... > > Not sure if option 3) is feasible. Sounds a little bit hacky and I > don't know if it's even possible to register a 'bogus' i2c client or > if it would break something somewhere that I'm not aware of. > > Oh and option 2) and 3) of course require an i2c bus driver to be > present and loaded. So in case someone has a system with a sch311x > that doesn't have a supported i2c controller, he/she couldn't load the > dme1737 driver... Not very nice... > > Does anybody have any suggestions or comments or other ideas? > While I was looking at writing a driver for an intel motherboard superio chip some time ago, I had the same problem, since this superio chip could be connected to either smbus or LPC. I then came up with the plan to first probe through LPC and then depending on the configuration (which can always be read through LPC in this case) register either an platfrom or a i2c client driver and matching device. Won't that work here? Regards, Hans
