On Mon, 29 Jun 2020, Masahiro Yamada wrote: > On Thu, Jun 25, 2020 at 11:57 PM Lee Jones <lee.jones@xxxxxxxxxx> wrote: > > > > On Thu, 25 Jun 2020, Masahiro Yamada wrote: > > > > > On Thu, Jun 25, 2020 at 3:16 AM Lee Jones <lee.jones@xxxxxxxxxx> wrote: > > > > > > > > On Thu, 25 Jun 2020, Masahiro Yamada wrote: > > > > > > > > > On Tue, Jun 23, 2020 at 9:24 PM Lee Jones <lee.jones@xxxxxxxxxx> wrote: > > > > > > > > > > > > On Tue, 23 Jun 2020, Masahiro Yamada wrote: > > > > > > > > > > > > > 'make ARCH=arm dtbs_check' emits the following warning: > > > > > > > > > > > > > > support-card@1,1f00000: $nodename:0: 'support-card@1,1f00000' does not match '^(bus|soc|axi|ahb|apb)(@[0-9a-f]+)?$' > > > > > > > > > > > > > > Maybe, simple-mfd could be a better fit for this device. > > > > > > > > > > > > The two should be equivalent. > > > > > > > > > > Yes, I know. > > > > > That's why I can change "simple-bus" to "simple-mfd" > > > > > with no risk. > > > > > > > > > > The difference is schema-check. > > > > > > > > > > The node name for "simple-bus" is checked by 'make dtbs_check'. > > > > > > > > > > See this code: > > > > > https://github.com/robherring/dt-schema/blob/v2020.05/schemas/simple-bus.yaml#L17 > > > > > > > > > > Even if I rename the node, it does not accept the > > > > > unit name '1,1f00000' > > > > > > > > > > > What do you mean by "maybe"? Does this squash the warning? > > > > > > > > > > "maybe" means I am not quite sure > > > > > which compatible is a better fit > > > > > to describe this device. > > > > > > > > > > As mentioned above, simple-bus and simple-mfd > > > > > are interchangeable from a driver point of view. > > > > > > > > > > This add-on board is integrated with various peripherals > > > > > such as 16550a serial, smsc9115 ether etc. > > > > > The address-decode is implemented in a CPLD device. > > > > > It has chip selects and local addresses, which are mapped to > > > > > the parent. > > > > > > > > > > It can be either simple-bus or simple-mfd, I think. > > > > > > > > > > > > > > > dt-schema checks the node name of simple-bus. > > > > > Currently, there is no check for simple-mfd. > > > > > > > > > > So, I think this patch is an easy solution > > > > > to fix the warning. > > > > > > > > Yes, looking at the documentation it seems as though 'simple-mfd' > > > > would be a better fit. Is the device a single IP with various > > > > different functions? > > > > > > Not an IP. > > > > > > This is a small board that consists of > > > a CPLD + ethernet controller + serial controller + LED, etc. > > > > Then simple MFD does not seem like a good fit. > > > > Neither does 'simple-bus'. > > Then, I do not know what to do. > > > This board connection is so simple > that no hardware initialization needed to get access > to peripherals. > > So, 'simple-bus' or 'simple-mfd' is preferred. > > If this is not either simple-bus or simple-mfd, > I need a special driver to probe the > child devices such as ethernet, serial etc. > > > > > What is it you're trying to describe in the device hierarchy? > > > The connection is as follows: > > > |-Main board -| |----- add-on board ----| > | | | (this board) | > | | | | > | (SoC) ---|------|--- CPLD --- ethernet | > | | | |- serial | > |-------------| | |- LED | > | | > |-----------------------| > > > > uniphier-support-card.dtsi describes the > "add-on board" part. > Address-decode is implemented in CPLD. > > > So, the criteria to become MFD is > whether it is an IP integrated into SoC. > > > - implemented in an SoC --> MFD If s/in an SoC/in a single piece of silicon/ ... then yes. > - implemented in a board + CPLD --> not MFD > > Right? Right. Unless all H/W is represented inside the CPLD, in which case the CPLD is, in theory, the MFD. Although, due to the nature of CPLDs, this is a slippery slope. You may want something like: arch/arm64/boot/dts/rockchip/rk3399-roc-pc-mezzanine.dts ... where the add-on board is represented separately (not in the same hierarchical structure as the main board. The main board is then included as a DTSI from the add-on board. It might also be worth looking at how consumer boards such as the RaspberryPi, BeagleBoard and the like handle their add-on boards, mezzanines, capes, hats, etc. -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog
