Hi Hans, On 6/28/07, Hans de Goede <j.w.r.degoede at hhs.nl> wrote: > 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? Well yes it would. That's in fact what I started doing. I just think it's kind of ugly to have 2 sets of device register/unregister methods in a single driver. I thought I'd run it by the list before spending more time on it. ...juerg > Regards, > > Hans > >
