| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20200915082348.2f6fff7a@aktux>
Date: Tue, 15 Sep 2020 08:23:48 +0200
From: Andreas Kemnade <andreas@...nade.info>
To: Rob Herring <robh@...nel.org>
Cc: Jonathan Neuschäfer <j.neuschaefer@....net>,
linux-kernel@...r.kernel.org, Lee Jones <lee.jones@...aro.org>,
Thierry Reding <thierry.reding@...il.com>,
Uwe Kleine-König
<u.kleine-koenig@...gutronix.de>,
Alessandro Zummo <a.zummo@...ertech.it>,
Alexandre Belloni <alexandre.belloni@...tlin.com>,
Shawn Guo <shawnguo@...nel.org>,
Sascha Hauer <s.hauer@...gutronix.de>,
Pengutronix Kernel Team <kernel@...gutronix.de>,
Fabio Estevam <festevam@...il.com>,
NXP Linux Team <linux-imx@....com>,
Sam Ravnborg <sam@...nborg.org>,
Linus Walleij <linus.walleij@...aro.org>,
Heiko Stuebner <heiko.stuebner@...obroma-systems.com>,
Stephan Gerhold <stephan@...hold.net>,
Lubomir Rintel <lkundrak@...sk>,
Mark Brown <broonie@...nel.org>, allen <allen.chen@....com.tw>,
Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
"David S. Miller" <davem@...emloft.net>,
devicetree@...r.kernel.org, linux-pwm@...r.kernel.org,
linux-rtc@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
Heiko Stuebner <heiko@...ech.de>,
Josua Mayer <josua.mayer@....eu>,
Arnd Bergmann <arnd@...db.de>, Daniel Palmer <daniel@...f.com>
Subject: Re: [PATCH v2 04/10] dt-bindings: pwm: Add bindings for PWM
function in Netronix EC
Hi,
On Mon, 14 Sep 2020 18:54:43 -0600
Rob Herring <robh@...nel.org> wrote:
> On Sat, Sep 05, 2020 at 03:32:24PM +0200, Jonathan Neuschäfer wrote:
> > The Netronix embedded controller as found in Kobo Aura and Tolino Shine
> > supports one PWM channel, which is used to control the frontlight
> > brightness on these devices.
> >
> > Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@....net>
> > ---
> >
> > v2:
> > - Add plaintext binding to patch description, for comparison
> > - Fix pwm-cells property (should be 2, not 1)
> > - Add dummy regulator to example, because the pwm-backlight binding requires a
> > power supply
> >
> >
> > For reference, here is the binding in text form:
> >
> >
> > PWM functionality in Netronix Embedded Controller
> >
> > Required properties:
> > - compatible: should be "netronix,ntxec-pwm"
> > - #pwm-cells: should be 2.
> >
> > Available PWM channels:
> > - 0: The PWM channel controlled by registers 0xa1-0xa7
> >
> > Example:
> >
> > embedded-controller@43 {
> > compatible = "netronix,ntxec";
> > ...
> >
> > ec_pwm: pwm {
> > compatible = "netronix,ntxec-pwm";
> > #pwm-cells = <1>;
> > };
> > };
> >
> > ...
> >
> > backlight {
> > compatible = "pwm-backlight";
> > pwms = <&ec_pwm 0 50000>;
> > };
> > ---
> > .../bindings/mfd/netronix,ntxec.yaml | 19 +++++++++++
> > .../bindings/pwm/netronix,ntxec-pwm.yaml | 33 +++++++++++++++++++
> > 2 files changed, 52 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> > index 596df460f98eb..73c873dda3e70 100644
> > --- a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> > +++ b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> > @@ -31,6 +31,9 @@ properties:
> > description:
> > The EC can signal interrupts via a GPIO line
> >
> > + pwm:
> > + $ref: ../pwm/netronix,ntxec-pwm.yaml
> > +
> > required:
> > - compatible
> > - reg
> > @@ -53,5 +56,21 @@ examples:
> > interrupts = <11 IRQ_TYPE_EDGE_FALLING>;
> > interrupt-controller;
> > #interrupt-cells = <1>;
> > +
> > + ec_pwm: pwm {
> > + compatible = "netronix,ntxec-pwm";
> > + #pwm-cells = <2>;
> > + };
> > };
> > };
> > +
> > + backlight {
> > + compatible = "pwm-backlight";
> > + pwms = <&ec_pwm 0 50000>;
> > + power-supply = <&backlight_regulator>;
> > + };
> > +
> > + backlight_regulator: regulator-dummy {
> > + compatible = "regulator-fixed";
> > + regulator-name = "backlight";
> > + };
> > diff --git a/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
> > new file mode 100644
> > index 0000000000000..0c9d2801b8de1
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
> > @@ -0,0 +1,33 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pwm/netronix,ntxec-pwm.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: PWM functionality in Netronix embedded controller
> > +
> > +maintainers:
> > + - Jonathan Neuschäfer <j.neuschaefer@....net>
> > +
> > +description: |
> > + See also Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
> > +
> > + The Netronix EC contains PWM functionality, which is usually used to drive
> > + the backlight LED.
> > +
> > + The following PWM channels are supported:
> > + - 0: The PWM channel controlled by registers 0xa1-0xa7
> > +
> > +allOf:
> > + - $ref: pwm.yaml#
> > +
> > +properties:
> > + compatible:
> > + const: netronix,ntxec-pwm
> > +
> > + "#pwm-cells":
> > + const: 2
>
> Just move this to the parent and make the parent a pwm provider. There's
> no need for child nodes for this or the rtc.
>
hmm, there are apparently devices without rtc. If there is a child node
for the rtc, the corresponding devicetrees could disable rtc by not
having that node.
But maybe using the controller version is also feasible for that task.
Regards,
Andreas
Powered by blists - more mailing lists