On Wed, Nov 2, 2016 at 11:45 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Wednesday 02 November 2016, Cédric Le Goater wrote: >> The Aspeed SoCs have two BT interfaces : one is IPMI compliant and the >> other is H8S/2168 compliant. >> >> The current ipmi/bt-bmc driver implements the IPMI version and we >> should reflect its nature in the compatible node name using >> 'aspeed,ast2400-ibt-bmc' instead of 'aspeed,ast2400-bt-bmc'. The >> latter should be used for a H8S interface driver if it is implemented >> one day. >> >> Signed-off-by: Cédric Le Goater <clg@xxxxxxxx> > > We generally try to avoid changing the compatible strings after the > fact, but it's probably ok in this case. > > I don't understand who decides which of the two interfaces is used: > is it the same register set that can be driven by either one or the > other driver, or do you expect to have two drivers that can both > be active in the same system and talk to different hardware once > you get there? It's the second case. The H8S BT has a different register layout so it would require a different driver. We don't yet have a driver for the other BT device, but there was recent talk of using it as an alternate (non-ipmi channel) between the BMC and the host. Before that discussion I wasn't aware that the H8S BT existed. I suggested we fix this up before it hits a final release. Cédric, do you think ast2400-ibt-bmc or ast2400-ipmi-bt-bmc does a better job of describing the hardware here? While we're modifying the binding, should we add a compat string for the ast2500? Cheers, Joel > > If the first one of these is true, it seems a little awkward to > use the DT compatible string to decide which driver to use rather > than making the decision in the OS. > > Arnd -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
