Messages in this thread | | | Subject | Re: [PATCH v2 01/15] dt-bindings: gpio: convert bindings for NXP PCA953x family to dtschema | From | Grygorii Strashko <> | Date | Fri, 11 Sep 2020 12:53:35 +0300 |
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On 11/09/2020 09:52, Krzysztof Kozlowski wrote: > On Fri, 11 Sep 2020 at 08:24, Joel Stanley <joel@jms.id.au> wrote: >> >> On Thu, 10 Sep 2020 at 17:57, Krzysztof Kozlowski <krzk@kernel.org> wrote: >>> >>> Convert the NXP PCA953x family of GPIO expanders bindings to device tree >>> schema. >>> >>> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> >> >>> +patternProperties: >>> + "^(hog-[0-9]+|.+-hog(-[0-9]+)?)$": >>> + type: object >>> + properties: >>> + gpio-hog: true >>> + gpios: true >>> + input: true >>> + output-high: true >>> + output-low: true >>> + line-name: true >>> + >>> + required: >>> + - gpio-hog >>> + - gpios >>> + >> >>> + usb3-sata-sel-hog { >>> + gpio-hog; >>> + gpios = <4 GPIO_ACTIVE_HIGH>; >>> + output-low; >>> + line-name = "usb3_sata_sel"; >> >> I would prefer we didn't require the addition of hte -hog prefix. It's >> mostly just a matter of taste, but I can think of a few more concrete >> reasons: >> >> We don't require -high or -low prefixes, so the node name doesn't need >> to describe the properties that will be found below. > > Thanks for the comments. > > It is not about properties (high or low) but the role of a device > node. The node names should represent a generic class of device (ePAPR > and device tree spec) and "hog" is such class. > > The Documentation/devicetree/bindings/gpio/fsl-imx-gpio.yaml already > uses such naming so the best would be to unify.
In my opinion, It's not right to define this on per gpio-controller and introduce such per gpio-controller restrictions.
More over, there is already generic schema for gpio hogs: gpio-hog.yaml Originally, gpio bindings were defined without restricting gpio hog node names and, generic schema follows this.
I think, the generic "gpio-hogs" sub-node may be introduced to place gpio hogs child nodes, if gpio hogs node names restriction need to be introduces (*which i'm not sure is reasonable*).
gpio@20 { gpio-hogs { yyy-hog { gpio-hog; gpios } }
But this require as gpio code as generic gpio schema update (with backward compatibility in mind).
> >> >> Changing around node names for existing boards carries with it the >> chance of userspace breakage (as sysfs paths change). I would prefer >> we avoid that if possible. > > The impact on userspace is indeed important, but are you sure that > hogs are visible to user-space via sysfs and configurable? I guess you > think of deprecated CONFIG_GPIO_SYSFS? > > Rob, > Any hints from you about hog-naming? > > Best regards, > Krzysztof >
-- Best regards, grygorii
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