On Mon, Nov 08, 2021 at 11:27:45AM +0000, Lee Jones wrote: > On Mon, 08 Nov 2021, Greg KH wrote: > > On Mon, Nov 08, 2021 at 11:04:31AM +0000, Lee Jones wrote: > > > On Mon, 08 Nov 2021, Kumaravel.Thiagarajan@xxxxxxxxxxxxx wrote: > > > > > > > Dear Lee Jones, > > > > > > > > I am Kumaravel Thiagarajan from Microchip, India and I am new to Linux Kernel development. > > > > > > > > I am currently working on linux kernel driver for one of our PCIe based devices whose BAR 0 maps interface registers for a gpio controller, an OTP memory device controller and an EEPROM device controller into the host processor's memory space. > > > > > > > > Based on earlier inputs from Linus Walleij, I have developed this as a multi-function device driver - First MFD driver (drivers/mfd) gets loaded for the PCIe device and then it spawns two child devices for OTP/EEPROM and GPIO separately. > > > > > > You may wish to speak with Greg about your architectural decisions. > > > > > > He usually dislikes the creation of platform devices from PCI ones. > > > > Yes, that is NOT ok. > > > > Platform devices are only for devices that are actually on a platform > > (i.e. described by DT or other firmware types). > > This is probably a bit of an over-simplification. Lots of legitimate > platform devices are actually described by DT et al. We are in violent agreement here, that is what I was trying to say :) > However, it is true that devices which reside on definite buses; PCI, > USB, PCMIA, SCSI, Thunderbolt, etc should not spawn their children off > as platform devices. Agreed, that is not ok, as those are not what the platform device code was designed for. thanks, greg k-h
