linux-kernel - Re: [PATCH 5/6] leds: pca963x: Inform the output that it is inverted

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20160421150750.GA3116@rob-hp-laptop>
Date:	Thu, 21 Apr 2016 10:07:50 -0500
From:	Rob Herring <robh@...nel.org>
To:	Olliver Schinagl <oliver@...inagl.nl>
Cc:	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Richard Purdie <rpurdie@...ys.net>,
	Jacek Anaszewski <j.anaszewski@...sung.com>,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-leds@...r.kernel.org
Subject: Re: [PATCH 5/6] leds: pca963x: Inform the output that it is inverted

On Tue, Apr 19, 2016 at 09:40:49AM +0200, Olliver Schinagl wrote:
> When leds are connected in a totem-pole configuration, they can be
> connected either in a active-high, or active-low manor. The driver
> currently always assumes active-high. This patch adds the
> 'nxp,inverted-out' boolean property to tell the driver that the leds
> are driven active-low, or rather, that the behavior is inverted to what
> is normally expected.

How do I know what is normally expected?

> Signed-off-by: Olliver Schinagl <oliver@...inagl.nl>
> ---
>  Documentation/devicetree/bindings/leds/pca963x.txt |  1 +
>  drivers/leds/leds-pca963x.c                        | 20 +++++++++++++-------
>  include/linux/platform_data/leds-pca963x.h         |  1 +
>  3 files changed, 15 insertions(+), 7 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/leds/pca963x.txt b/Documentation/devicetree/bindings/leds/pca963x.txt
> index dafbe99..7b23725 100644
> --- a/Documentation/devicetree/bindings/leds/pca963x.txt
> +++ b/Documentation/devicetree/bindings/leds/pca963x.txt
> @@ -6,6 +6,7 @@ Required properties:
>  Optional properties:
>  - nxp,totem-pole : use totem pole (push-pull) instead of open-drain (pca9632 defaults
>    to open-drain, newer chips to totem pole)
> +  nxp,inverted-out: the connected leds are active-low, default to active-high

Just state what mode you want: nxp,active-low

Rob