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 9268AC433F5 for ; Fri, 8 Apr 2022 11:18:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232650AbiDHLUV (ORCPT ); Fri, 8 Apr 2022 07:20:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229452AbiDHLUS (ORCPT ); Fri, 8 Apr 2022 07:20:18 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB50E3A37A0 for ; Fri, 8 Apr 2022 04:18:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 53983B82A51 for ; Fri, 8 Apr 2022 11:18:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE5B1C385A3; Fri, 8 Apr 2022 11:18:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649416692; bh=/m0sOMkIY+YH/xMizj3AEsdT5/nMANVS7C4zn00Dcoc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IUfg3W95tcHxKLDG6N0ysbpPiIz+skActS1vj4iycbyIagilzHpBXbQOC3rKJ/Ly/ hDo9o6/SouLzvC2CWO43syU8n87BIyPd7Rkxy8EXYOX5fIZ52ZUEynkZ5BH+znJnrC S62qrTks/jec/1uxiKywIohunzOGdt841Jg3xM3STgO7qc4zsAiuv67y5yXUXgEhOU k+1O5QX5XU/WP16f1zKD9Ph72cU1LF5qiMb0ODLYMyUSe+LFQJ3Batc5CfsAXpjtzq oCenxiCprcaXXoj7GxNrgwnZPbW1SQPmvTPKDWY9DjY1w6MGflVdwYveIWuh1sXI56 WqEQS3s3BiFxA== Date: Fri, 8 Apr 2022 12:18:06 +0100 From: Mark Brown To: Javier Martinez Canillas Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Andy Shevchenko , Chen-Yu Tsai , Geert Uytterhoeven , Chen-Yu Tsai , Daniel Vetter , David Airlie , Maxime Ripard , YueHaibing Subject: Re: [PATCH 5/5] drm/solomon: Add SSD130x OLED displays SPI support Message-ID: References: <20220407200205.28838-1-javierm@redhat.com> <20220407200205.28838-6-javierm@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="g1yK6P6SAt6g6CTu" Content-Disposition: inline In-Reply-To: <20220407200205.28838-6-javierm@redhat.com> X-Cookie: Look ere ye leap. Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --g1yK6P6SAt6g6CTu Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Apr 07, 2022 at 10:02:04PM +0200, Javier Martinez Canillas wrote: > The ssd130x driver only provides the core support for these devices but it > does not have any bus transport logic. Add a driver to interface over SPI. >=20 > There is a difference in the communication protocol when using 4-wire SPI > instead of I2C. For the latter, a control byte that contains a D/C# field > has to be sent. This field tells the controller whether the data has to be > written to the command register or to the graphics display data memory. >=20 > But for 4-wire SPI that control byte is not used, instead a real D/C# line > must be pulled HIGH for commands data and LOW for graphics display data. >=20 > For this reason the standard SPI regmap can't be used and a custom .write > bus handler is needed. Acked-by: Mark Brown --g1yK6P6SAt6g6CTu Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmJQGe0ACgkQJNaLcl1U h9AIOQf/WM+DQ3uZHPaIQ5Aa2QPhp1jUAe6hJOZPDcPKGVkxfwwWLN0Dv0AS6MNv RrM5wv7Yvqp1vvAQ1srOtZJgLWYpVyzWQEpr2i2CUvX5rIiX6d8iAspK5HbcbMon RSWXcItCHZjj/CacdEkjZp1ZHCwmxLmPJ6BajKoZCdnDWu/1/+Y5V6C3kHUbPgl7 46wTkUzXoPBS25rHOyAQmhcsEgvP9mL9mQ7JwSfEI6gsBAy61fxrgZiPcxJWef0Y P8jnTv65wR5m7KNc09i0m9MaMubatw9laXRYRc3UHjlVX44vAte1lzvBJdem4+YV s8o2HpkntpTn+bn87ONIk+eb5Y8DeA== =rvVz -----END PGP SIGNATURE----- --g1yK6P6SAt6g6CTu--