On Thu, Aug 10, 2023 at 8:19 AM Yinbo Zhu <zhuyinbo@xxxxxxxxxxx> wrote: > > > > 在 2023/8/9 下午11:39, Conor Dooley 写道: > > On Wed, Aug 09, 2023 at 03:47:55PM +0800, Yinbo Zhu wrote: > >> 在 2023/8/8 下午8:05, Conor Dooley 写道: > >>> On Mon, Aug 07, 2023 at 03:40:42PM +0800, Yinbo Zhu wrote: > > > >>>> + loongson,gpio-ctrl-mode: > >>>> + $ref: /schemas/types.yaml#/definitions/uint32 > >>>> + description: > >>>> + This option indicate this GPIO control mode, where '0' represents > >>>> + bit control mode and '1' represents byte control mode. > >>> > >>> How is one supposed to know which of these modes to use? > >> > >> > >> Byte mode is to access by byte, such as gpio3, the base address of the > >> gpio controller is offset by 3 bytes as the access address of gpio3. > >> > >> The bit mode is the normal mode that like other platform gpio and it is > >> to access by bit. > >> > >> If both modes are supported, it is recommended to prioritize using byte > >> mode that according to spec. > > > > So, sounds like this property should instead be a boolean that notes > > whether the hardware supports the mode or not, rather than the current > > enum used to determine software policy. > > > okay, I got it, I will use boolean, > Why do you want to put it into device-tree so badly? This is not the first driver that would have of_match_data for different variants where you can have a structure that would keep offsets for different models. It's not like you will have hundreds of "compatible" chips anyway, most likely just a few? Bart
