| Message ID | 20190902090633.24239-1-linus.walleij@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/2] drm/panel: Add DT bindings for Sony ACX424AKP | expand |
On Mon, Sep 02, 2019 at 11:06:32AM +0200, Linus Walleij wrote: > This adds device tree bindings for the Sony ACX424AKP panel. > Let's use YAML. > > Cc: devicetree@vger.kernel.org > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > .../display/panel/sony,acx424akp.yaml | 53 +++++++++++++++++++ > 1 file changed, 53 insertions(+) > create mode 100644 Documentation/devicetree/bindings/display/panel/sony,acx424akp.yaml > > diff --git a/Documentation/devicetree/bindings/display/panel/sony,acx424akp.yaml b/Documentation/devicetree/bindings/display/panel/sony,acx424akp.yaml > new file mode 100644 > index 000000000000..29f41fee1b69 > --- /dev/null > +++ b/Documentation/devicetree/bindings/display/panel/sony,acx424akp.yaml > @@ -0,0 +1,53 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/display/panel/sony,acx424akp.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Sony ACX424AKP 4" 480x864 AMOLED panel > + > +maintainers: > + - Linus Walleij <linus.walleij@linaro.org> > + > +allOf: > + - $ref: panel-common.yaml# > + > +properties: > + compatible: > + const: sony,acx424akp > + reg: true > + port: true > + reset-gpios: true > + vddi-supply: > + description: regulator that supplies the vddi voltage > + dsi-command-mode: > + type: boolean > + description: > + If this is specified, the panel will be used in command > + mode instead of video mode. I'm not sure there's concensus on this one yet. I think so far the driver decides which mode to use the panel in. Technically this falls into the category of configuration, so it doesn't really belong in the DT. I vaguely recall from discussions I've had on this subject that there's usually no reason to do video mode if you can do command mode because command mode is more power efficient. This was a long time ago, so I may be misremembering. Perhaps you have different information on this? Thierry > + > +required: > + - compatible > + - reg > + - port > + - reset-gpios > + - power-supply > + > +additionalProperties: false > + > +examples: > + - | > + panel@0 { > + compatible = "sony,acx424akp"; > + reg = <0>; > + vddi-supply = <&foo>; > + reset-gpios = <&foo_gpio 0 GPIO_ACTIVE_LOW>; > + > + port { > + panel_in: endpoint { > + remote-endpoint = <&dsi_out>; > + }; > + }; > + }; > + > +... > \ No newline at end of file > -- > 2.21.0 >
On Mon, Sep 2, 2019 at 11:35 AM Thierry Reding <thierry.reding@gmail.com> wrote: > > + dsi-command-mode: > > + type: boolean > > + description: > > + If this is specified, the panel will be used in command > > + mode instead of video mode. > > I'm not sure there's concensus on this one yet. I think so far the > driver decides which mode to use the panel in. Technically this falls > into the category of configuration, so it doesn't really belong in the > DT. The way we've used DT is for a bit of both hardware description and configuration I'd say, but I'm no authority on the subject. > I vaguely recall from discussions I've had on this subject that there's > usually no reason to do video mode if you can do command mode because > command mode is more power efficient. This was a long time ago, so I may > be misremembering. Perhaps you have different information on this? No idea. I was under the impression that video mode was preferred but I have no idea why. Yours, Linus Walleij
On Mon, Sep 02, 2019 at 04:40:06PM +0200, Thierry Reding wrote: > On Mon, Sep 02, 2019 at 01:44:38PM +0200, Linus Walleij wrote: > > On Mon, Sep 2, 2019 at 11:35 AM Thierry Reding <thierry.reding@gmail.com> wrote: > > > > > > + dsi-command-mode: > > > > + type: boolean > > > > + description: > > > > + If this is specified, the panel will be used in command > > > > + mode instead of video mode. > > > > > > I'm not sure there's concensus on this one yet. I think so far the > > > driver decides which mode to use the panel in. Technically this falls > > > into the category of configuration, so it doesn't really belong in the > > > DT. > > > > The way we've used DT is for a bit of both hardware description > > and configuration I'd say, but I'm no authority on the subject. I'm okay with this if there's consensus, but it should be in a common doc. We probably need a dsi-commom schema with this, reg, ??. > > > > > I vaguely recall from discussions I've had on this subject that there's > > > usually no reason to do video mode if you can do command mode because > > > command mode is more power efficient. This was a long time ago, so I may > > > be misremembering. Perhaps you have different information on this? 30 or 60fps updates tend to be impossible because you have less b/w and it's async to the refresh. I think most panels that can do both, always need command mode too for initialization. > > No idea. I was under the impression that video mode was preferred > > but I have no idea why. > > Hm... my recollection is that command mode is only supported on "smart" > panels that have an internal framebuffer. So the commands actually > instruct the panel to update their internal framebuffer, which means you > can technically switch off the display engine when there are no updates. > > Under those circumstances I think it'd make sense to default to command > mode if both the panel and the host support it and stick with video mode > if for example the host can't do command mode. > > Or perhaps this is something that could be set from some userspace > policy maker via a connector property? A compositor for instance would > have a pretty good idea of what kind of activity is going on, so it > could at some point decide to switch between video mode and command mode > if one of them is more appropriate for the given workload. > > Command mode can also be used to do partial updates, if I remember > correctly, which again would make it possible for a compositor to send > only a subset of a screen update. All makes sense to me. Rob
diff --git a/Documentation/devicetree/bindings/display/panel/sony,acx424akp.yaml b/Documentation/devicetree/bindings/display/panel/sony,acx424akp.yaml new file mode 100644 index 000000000000..29f41fee1b69 --- /dev/null +++ b/Documentation/devicetree/bindings/display/panel/sony,acx424akp.yaml @@ -0,0 +1,53 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/display/panel/sony,acx424akp.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Sony ACX424AKP 4" 480x864 AMOLED panel + +maintainers: + - Linus Walleij <linus.walleij@linaro.org> + +allOf: + - $ref: panel-common.yaml# + +properties: + compatible: + const: sony,acx424akp + reg: true + port: true + reset-gpios: true + vddi-supply: + description: regulator that supplies the vddi voltage + dsi-command-mode: + type: boolean + description: + If this is specified, the panel will be used in command + mode instead of video mode. + +required: + - compatible + - reg + - port + - reset-gpios + - power-supply + +additionalProperties: false + +examples: + - | + panel@0 { + compatible = "sony,acx424akp"; + reg = <0>; + vddi-supply = <&foo>; + reset-gpios = <&foo_gpio 0 GPIO_ACTIVE_LOW>; + + port { + panel_in: endpoint { + remote-endpoint = <&dsi_out>; + }; + }; + }; + +... \ No newline at end of file
This adds device tree bindings for the Sony ACX424AKP panel. Let's use YAML. Cc: devicetree@vger.kernel.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- .../display/panel/sony,acx424akp.yaml | 53 +++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 Documentation/devicetree/bindings/display/panel/sony,acx424akp.yaml -- 2.21.0