linux-kernel - Re: [PATCH v2 8/8] DT:omap3+ads7846: use new common touchscreen bindings

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: <CANOLnOO=J=se7K7GnJZPrkXJpm-_+vshsRUCeWo1GVsum8jyeg@mail.gmail.com>
Date:	Mon, 16 Nov 2015 16:37:12 +0200
From:	Grazvydas Ignotas <notasas@...il.com>
To:	"H. Nikolaus Schaller" <hns@...delico.com>
Cc:	Rob Herring <robh+dt@...nel.org>, Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Benoît Cousson <bcousson@...libre.com>,
	Tony Lindgren <tony@...mide.com>,
	Russell King <linux@....linux.org.uk>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Hans Verkuil <hans.verkuil@...co.com>,
	Mauro Carvalho Chehab <mchehab@....samsung.com>,
	Sebastian Reichel <sre@...nel.org>,
	Haibo Chen <haibo.chen@...escale.com>,
	Andrey Gelman <andrey.gelman@...pulab.co.il>,
	Igor Grinberg <grinberg@...pulab.co.il>,
	Aaron Sierra <asierra@...-inc.com>,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	devicetree@...r.kernel.org,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-omap@...r.kernel.org" <linux-omap@...r.kernel.org>,
	gta04-owner@...delico.com, linux-input@...r.kernel.org
Subject: Re: [PATCH v2 8/8] DT:omap3+ads7846: use new common touchscreen bindings

Hi,

On Fri, Nov 13, 2015 at 10:35 PM, H. Nikolaus Schaller
<hns@...delico.com> wrote:
> The standard touch screen bindings [1] replace the private ti,swap-xy
> with touchscreen-swaped-x-y. And for the Openpandora we use
> touchscreen-size etc. to match the LCD screen size.
>
> [1]: Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
>
> Signed-off-by: H. Nikolaus Schaller <hns@...delico.com>
> ---
>  arch/arm/boot/dts/omap3-lilly-a83x.dtsi              |  2 +-
>  arch/arm/boot/dts/omap3-pandora-common.dtsi          | 17 +++++++++++++----
>  arch/arm/boot/dts/omap3-panel-sharp-ls037v7dw01.dtsi |  2 +-
>  3 files changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/boot/dts/omap3-lilly-a83x.dtsi b/arch/arm/boot/dts/omap3-lilly-a83x.dtsi
> index d0dd036..01dae66 100644
> --- a/arch/arm/boot/dts/omap3-lilly-a83x.dtsi
> +++ b/arch/arm/boot/dts/omap3-lilly-a83x.dtsi
> @@ -325,7 +325,7 @@
>                 ti,y-max = /bits/ 16 <3600>;
>                 ti,x-plate-ohms = /bits/ 16 <80>;
>                 ti,pressure-max = /bits/ 16 <255>;
> -               ti,swap-xy;
> +               touchscreen-swapped-x-y;
>
>                 linux,wakeup;
>         };
> diff --git a/arch/arm/boot/dts/omap3-pandora-common.dtsi b/arch/arm/boot/dts/omap3-pandora-common.dtsi
> index f672a04..9497cc6 100644
> --- a/arch/arm/boot/dts/omap3-pandora-common.dtsi
> +++ b/arch/arm/boot/dts/omap3-pandora-common.dtsi
> @@ -696,10 +696,19 @@
>                 pendown-gpio = <&gpio3 30 0>;
>                 vcc-supply = <&vaux4>;
>
> -               ti,x-min = /bits/ 16 <0>;
> -               ti,x-max = /bits/ 16 <8000>;
> -               ti,y-min = /bits/ 16 <0>;
> -               ti,y-max = /bits/ 16 <4800>;
> +               touchscreen-size-x = <800>;
> +               touchscreen-size-y = <480>;
> +               touchscreen-max-pressure = <1000>;
> +               touchscreen-fuzz-x = <16>;
> +               touchscreen-fuzz-y = <16>;
> +               touchscreen-fuzz-pressure = <10>;
> +               touchscreen-inverted-x;
> +               touchscreen-inverted-y;
> +
> +               ti,x-min = /bits/ 16 <160>;
> +               ti,x-max = /bits/ 16 <3900>;
> +               ti,y-min = /bits/ 16 <220>;
> +               ti,y-max = /bits/ 16 <3750>;

I'm not sure this is a good idea, there have been at least 3 different
batches of LCDs which slightly different touchscreens attached, with
such thresholds we might end up with unreachable touchscreen points on
some units. If I understand right, calibration won't help if for some
screen locations ADC reading goes below/above these min/max thresholds
on some specific units? If so there should probably be at least 10%
margin in either case to make calibration useful.

Gražvydas
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/