From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E818FC10F1B for ; Tue, 13 Dec 2022 18:50:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236453AbiLMSuZ (ORCPT ); Tue, 13 Dec 2022 13:50:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235488AbiLMSuX (ORCPT ); Tue, 13 Dec 2022 13:50:23 -0500 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB0CDF5F; Tue, 13 Dec 2022 10:50:21 -0800 (PST) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id AEFD21C09F4; Tue, 13 Dec 2022 19:50:19 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ucw.cz; s=gen1; t=1670957419; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=3i41IrgXQW1S6iU+2m3xA/OqmXK1LICZ0Uy6hCM9JWs=; b=l7EIGIrdYfcGP7SzrT6VL2hG2CedmYOUeCMcKTWN2LK1XUMJy8Dz/JRyZXWzts9iUbfW/j 9+rHUM8qAHJMCPFtcs2jqXVTgR7qIMbYf41le0I0ZSw5HPrJpq/vmsHli0J69e4+fpWwxK 1lkf+UudxYeG/oLyDDQ+K7ksBQLWRVk= Date: Tue, 13 Dec 2022 19:50:21 +0100 From: Pavel Machek To: Chuanhong Guo Cc: linux-leds@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Stanislav Jakubek , Linus Walleij , Shawn Guo , Johan Hovold , Bjorn Andersson , Marijn Suijten , Sven Schwermer , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list Subject: Re: [PATCH v3 0/3] leds: add driver for SPI driven WorldSemi WS2812B RGB LEDs Message-ID: References: <20221207040904.582585-1-gch981213@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="jFBQcuIEZxZsLN2I" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --jFBQcuIEZxZsLN2I Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > > This patch adds support for driving a chain of WS2812B LED chips > > > using SPI bus. > > > > > > WorldSemi WS2812B is a individually addressable LED chip that > > > can be chained together and controlled individually using a > > > single wire. The chip recognize a long pulse as a bit of 1 and > > > a short pulse as a bit of 0. Host sends a continuous stream > > > of 24-bits color values, each LED chip takes the first 3 byte > > > it receives as its color value and passes the leftover bytes to > > > the next LED on the chain. > > > > > > This driver simulates this protocol using SPI bus by sending > > > a long pulse as 3'b110 and a short pulse as 3'b100. The SPI > > > frequency needs to be 2.105MHz~2.85MHz for the timing to be > > > correct and the controller needs to transfer all the bytes > > > continuously. > > > > Is this the same thing as NeoPixel? If so, that may be better-known > > name. >=20 > NeoPixel is the name used by Adafruit for WS2812B based LED > strips. Even though that name may be better-known, this driver > is for the WS2812B LED chips, not for the specific Adafruit > products made using those chips. So I think it's more appropriate > to go with worldsemi,ws2812b instead of NeoPixel for the driver > name. Still, it would be suitable to mention the "NeoPixel" name in the comment at begining of driver, and in Kconfig text. Best regards, Pavel --=20 People of Russia, stop Putin before his war on Ukraine escalates. --jFBQcuIEZxZsLN2I Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCY5jJbQAKCRAw5/Bqldv6 8hVlAJwMcGl9MGvTjaV55V1EavnmdPtuwwCfdciSmOxidUdQRvEJkYbtQO5302A= =5mf7 -----END PGP SIGNATURE----- --jFBQcuIEZxZsLN2I--