| Message ID | 20200812085850.2643820-1-linus.walleij@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3,v2] dt-bindings: backlight: Add some common backlight properties | expand |
On Wed, Aug 12, 2020 at 2:58 AM Linus Walleij <linus.walleij@linaro.org> wrote: > > Let's use a common.yaml include for the backlight like we do with > the LEDs. The LEDs are inherently incompatible so their bindings > cannot be reused for backlight. > > Cc: devicetree@vger.kernel.org > Suggested-by: Sam Ravnborg <sam@ravnborg.org> > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > ChangeLog v1->v2: > - New patch as suggested by Sam. > --- > .../bindings/leds/backlight/common.yaml | 42 +++++++++++++++++++ > 1 file changed, 42 insertions(+) > create mode 100644 Documentation/devicetree/bindings/leds/backlight/common.yaml I'd expect some refactoring here with existing backlight schemas including the ones I just added for 5.9. Ideally, we shouldn't have any property have a type definition more than once. (We don't have any way to detect that though it wouldn't be hard to write a program to do so). > diff --git a/Documentation/devicetree/bindings/leds/backlight/common.yaml b/Documentation/devicetree/bindings/leds/backlight/common.yaml > new file mode 100644 > index 000000000000..8ae7e3818b0d > --- /dev/null > +++ b/Documentation/devicetree/bindings/leds/backlight/common.yaml > @@ -0,0 +1,42 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/leds/backlight/common.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Common backlight properties > + > +maintainers: > + - Lee Jones <lee.jones@linaro.org> > + - Daniel Thompson <daniel.thompson@linaro.org> > + - Jingoo Han <jingoohan1@gmail.com> > + > +description: | You don't need '|' if there's no formatting to preserve. > + Backlight devices provide backlight for different types of graphical > + displays. They are typically but not necessarilt implemented using a white typo > + LED powered by a boost converter. > + > +properties: > + default-on: > + description: > + The initial state of the backlight can be set to be on with this > + property. This is a state applied by the operating system so that the > + backlight is always turned on at boot. Needs a type. > + > + default-brightness: > + description: > + The default brightness that should be applied to the LED by the operating > + system on start-up. The brightness should not exceed the brightness the > + LED can provide. > + $ref: /schemas/types.yaml#definitions/uint32 > + minimum: 0 It's an unsigned int, so the min is already 0. > + > + max-brightness: > + description: > + Normally the maximum brightness is determined by the hardware and this > + property is not required. This property is used to put a software limit > + on the brightness apart from what the driver says, as it could happen > + that a LED can be made so bright that it gets damaged or causes damage > + due to restrictions in a specific system, such as mounting conditions. > + $ref: /schemas/types.yaml#definitions/uint32 > + minimum: 0
On Wed, Aug 12, 2020 at 10:58:48AM +0200, Linus Walleij wrote: > Let's use a common.yaml include for the backlight like we do with > the LEDs. The LEDs are inherently incompatible so their bindings > cannot be reused for backlight. > > Cc: devicetree@vger.kernel.org > Suggested-by: Sam Ravnborg <sam@ravnborg.org> > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > ChangeLog v1->v2: > - New patch as suggested by Sam. > --- > .../bindings/leds/backlight/common.yaml | 42 +++++++++++++++++++ > 1 file changed, 42 insertions(+) > create mode 100644 Documentation/devicetree/bindings/leds/backlight/common.yaml > > diff --git a/Documentation/devicetree/bindings/leds/backlight/common.yaml b/Documentation/devicetree/bindings/leds/backlight/common.yaml > new file mode 100644 > index 000000000000..8ae7e3818b0d > --- /dev/null > +++ b/Documentation/devicetree/bindings/leds/backlight/common.yaml > @@ -0,0 +1,42 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/leds/backlight/common.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Common backlight properties > + > +maintainers: > + - Lee Jones <lee.jones@linaro.org> > + - Daniel Thompson <daniel.thompson@linaro.org> > + - Jingoo Han <jingoohan1@gmail.com> > + > +description: | > + Backlight devices provide backlight for different types of graphical > + displays. They are typically but not necessarilt implemented using a white > + LED powered by a boost converter. > + > +properties: > + default-on: > + description: > + The initial state of the backlight can be set to be on with this > + property. This is a state applied by the operating system so that the > + backlight is always turned on at boot. Is default-on really a common property? I would describe it as legacy that emerged when we added the gpio bindings and didn't spell default-brightness correctly! Currently I think this is only implemented for GPIO and it is simply not needed for most hardware. More specifically, for hardware that is capable of flicker-free handover (bootloader -> kernel) by examining the hardware state at handover then we don't want a DT property. It is duplicative and can only result in bad handovers. Daniel.
On Wed, Aug 12, 2020 at 5:46 PM Rob Herring <robh@kernel.org> wrote: > On Wed, Aug 12, 2020 at 2:58 AM Linus Walleij <linus.walleij@linaro.org> wrote: > > > > Let's use a common.yaml include for the backlight like we do with > > the LEDs. The LEDs are inherently incompatible so their bindings > > cannot be reused for backlight. > > > > Cc: devicetree@vger.kernel.org > > Suggested-by: Sam Ravnborg <sam@ravnborg.org> > > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > > --- > > ChangeLog v1->v2: > > - New patch as suggested by Sam. > > --- > > .../bindings/leds/backlight/common.yaml | 42 +++++++++++++++++++ > > 1 file changed, 42 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/leds/backlight/common.yaml > > I'd expect some refactoring here with existing backlight schemas > including the ones I just added for 5.9. Yeah if it takes off I can certainly make a slew of refactorings, I would like to do that once this is applied. > > + LED powered by a boost converter. > > + > > +properties: > > + default-on: > > + description: > > + The initial state of the backlight can be set to be on with this > > + property. This is a state applied by the operating system so that the > > + backlight is always turned on at boot. > > Needs a type. Dropping this property because the subsystem maintainer doubts this is needed. Fixed the rest! Yours, Linus Walleij
diff --git a/Documentation/devicetree/bindings/leds/backlight/common.yaml b/Documentation/devicetree/bindings/leds/backlight/common.yaml new file mode 100644 index 000000000000..8ae7e3818b0d --- /dev/null +++ b/Documentation/devicetree/bindings/leds/backlight/common.yaml @@ -0,0 +1,42 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/leds/backlight/common.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Common backlight properties + +maintainers: + - Lee Jones <lee.jones@linaro.org> + - Daniel Thompson <daniel.thompson@linaro.org> + - Jingoo Han <jingoohan1@gmail.com> + +description: | + Backlight devices provide backlight for different types of graphical + displays. They are typically but not necessarilt implemented using a white + LED powered by a boost converter. + +properties: + default-on: + description: + The initial state of the backlight can be set to be on with this + property. This is a state applied by the operating system so that the + backlight is always turned on at boot. + + default-brightness: + description: + The default brightness that should be applied to the LED by the operating + system on start-up. The brightness should not exceed the brightness the + LED can provide. + $ref: /schemas/types.yaml#definitions/uint32 + minimum: 0 + + max-brightness: + description: + Normally the maximum brightness is determined by the hardware and this + property is not required. This property is used to put a software limit + on the brightness apart from what the driver says, as it could happen + that a LED can be made so bright that it gets damaged or causes damage + due to restrictions in a specific system, such as mounting conditions. + $ref: /schemas/types.yaml#definitions/uint32 + minimum: 0
Let's use a common.yaml include for the backlight like we do with the LEDs. The LEDs are inherently incompatible so their bindings cannot be reused for backlight. Cc: devicetree@vger.kernel.org Suggested-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v1->v2: - New patch as suggested by Sam. --- .../bindings/leds/backlight/common.yaml | 42 +++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/devicetree/bindings/leds/backlight/common.yaml