From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751516AbdHDSEv (ORCPT ); Fri, 4 Aug 2017 14:04:51 -0400 Received: from smtp.domeneshop.no ([194.63.252.55]:52692 "EHLO smtp.domeneshop.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751208AbdHDSEt (ORCPT ); Fri, 4 Aug 2017 14:04:49 -0400 Subject: Re: [PATCH v3 3/6] dt-bindings: add binding for Sitronix ST7586 display panels To: David Lechner , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org Cc: Daniel Vetter , David Airlie , Rob Herring , Mark Rutland , Sekhar Nori , Kevin Hilman , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <1501799630-1650-1-git-send-email-david@lechnology.com> <1501799630-1650-4-git-send-email-david@lechnology.com> <66f0b765-928e-1fca-9588-99da747749a5@tronnes.org> From: =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= Message-ID: <20c044a4-cefe-7fed-8c5d-af27829c0648@tronnes.org> Date: Fri, 4 Aug 2017 20:04:25 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Den 04.08.2017 18.51, skrev David Lechner: > On 08/04/2017 04:48 AM, Noralf Trønnes wrote: >> >> Den 04.08.2017 00.33, skrev David Lechner: >>> This adds a new binding for Sitronix ST7586 display panels. >>> >>> Using lego as the vendor prefix in the compatible string because the >>> display >>> panel I am working with is an integral part of the LEGO MINDSTORMS EV3. >> >> Is this display available outside of this Lego part? > No, it is not. > >> If not you can remove the properties you don't need for this particular >> display setup. Another st7586 display with a different panel would need >> a different initialization sequence and compatible string, so we can >> add properties when/if that happens. > > OK. so I will drop power-supply and backlight. > And the dc/reset gpios should be required properties since your display won't work without them (or rather they're hardwired that way). > Should I remove these from the driver as well? There are some panels > out there that could use them.[1] > > [1]: > http://www.buydisplay.com/download/manual/ERC240160-1_Series_Datasheet.pdf > Yes, because that display won't work with the driver as-is, so it's really dead code. If someone wants to add support for that display, they'll add the necessary code. When maintaining code for 10-20 years, it's important to not add code that 'might' be used in the future. Let the future take care of itself and keep the codebase slim :-) Noralf. >> >> Noralf. >> >>> Signed-off-by: David Lechner >>> --- >>> .../bindings/display/sitronix,st7586.txt | 26 >>> ++++++++++++++++++++++ >>> 1 file changed, 26 insertions(+) >>> create mode 100644 >>> Documentation/devicetree/bindings/display/sitronix,st7586.txt >>> >>> diff --git >>> a/Documentation/devicetree/bindings/display/sitronix,st7586.txt >>> b/Documentation/devicetree/bindings/display/sitronix,st7586.txt >>> new file mode 100644 >>> index 0000000..dfb0b7b >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/display/sitronix,st7586.txt >>> @@ -0,0 +1,26 @@ >>> +Sitronix ST7586 display panel >>> + >>> +Required properties: >>> +- compatible: "lego,ev3-lcd". >>> + >>> +The node for this driver must be a child node of a SPI controller, >>> hence >>> +all mandatory properties described in ../spi/spi-bus.txt must be >>> specified. >>> + >>> +Optional properties: >>> +- dc-gpios: D/C pin. The presence/absence of this GPIO determines >>> + the panel interface operation mode (IF[3:1] pins): >>> + - present: IF=011 4-wire 8-bit data serial interface >>> + - absent: IF=010 3-wire 9-bit data serial interface >>> +- reset-gpios: Reset pin >>> +- power-supply: A regulator node for the supply voltage. >>> +- backlight: phandle of the backlight device attached to the panel >>> +- rotation: panel rotation in degrees counter clockwise >>> (0,90,180,270) >>> + >>> +Example: >>> + display@0{ >>> + compatible = "lego,ev3-lcd"; >>> + reg = <0>; >>> + spi-max-frequency = <10000000>; >>> + dc-gpios = <&gpio 43 GPIO_ACTIVE_HIGH>; >>> + reset-gpios = <&gpio 80 GPIO_ACTIVE_HIGH>; >>> + }; >> >