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 CA36CC433EF for ; Thu, 17 Feb 2022 14:35:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241769AbiBQOff (ORCPT ); Thu, 17 Feb 2022 09:35:35 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:44048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231239AbiBQOfe (ORCPT ); Thu, 17 Feb 2022 09:35:34 -0500 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [IPv6:2001:67c:2050::465:101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7AF1A2B1671; Thu, 17 Feb 2022 06:35:19 -0800 (PST) Received: from smtp1.mailbox.org (smtp1.mailbox.org [IPv6:2001:67c:2050:105:465:1:1:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4Jzy6C1S0mz9sV1; Thu, 17 Feb 2022 15:35:15 +0100 (CET) X-Virus-Scanned: amavisd-new at heinlein-support.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1645108512; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zURhBcd1HznQnraXISg5dKkf+eFuRNWJeFqODzAj4Is=; b=BjrfX8bcB3YJObvV4YlFB03EY5OIzuxs17s5/nsBEfejpK7EZi++mQoqrfNmyYctMhXNce v+hyrgLIeurSyIXglItUOeZx+fq0Iu2sVRQTJZt8Twkyz3aKP/pyOONg0goNWZywqTYouJ ApizqO/WhUT2SBhXMXxfPEhDwGXbvVfJ0ZqlJxbZCz7wQmylTV6t1qGZfCxOHn6VIg5mwE PHXys+B1hCqczGxbeNGUSo9P5P7c1ZVjRx/KY96AbyGQV/UfvJw9HjH1U6fy1ao9IEEpRX s9fzbVCKh6F5MQYawSmoKBfvNVE/zOiTAWdkrAWPXXZXUknbziYEfVDY9V2poQ== Message-ID: <863b1032-754d-d6ca-cef1-f6a271ae92ef@mailbox.org> Date: Thu, 17 Feb 2022 15:35:08 +0100 MIME-Version: 1.0 Subject: Re: [PATCH 8/8] drm/fourcc: Add DRM_FORMAT_D1 Content-Language: en-CA To: Pekka Paalanen , Geert Uytterhoeven Cc: Linux Fbdev development list , Thomas Zimmermann , David Airlie , Helge Deller , Javier Martinez Canillas , Linux Kernel Mailing List , Linux/m68k , DRI Development References: <20220215165226.2738568-1-geert@linux-m68k.org> <20220215165226.2738568-9-geert@linux-m68k.org> <20220217121033.0fc7f6ba@eldfell> <20220217162823.050d5f17@eldfell> From: =?UTF-8?Q?Michel_D=c3=a4nzer?= In-Reply-To: <20220217162823.050d5f17@eldfell> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org On 2022-02-17 15:28, Pekka Paalanen wrote: > On Thu, 17 Feb 2022 11:42:29 +0100 > Geert Uytterhoeven wrote: > >> Hi Pekka, >> >> On Thu, Feb 17, 2022 at 11:10 AM Pekka Paalanen wrote: >>> On Tue, 15 Feb 2022 17:52:26 +0100 >>> Geert Uytterhoeven wrote: >>>> Introduce a fourcc code for a single-channel frame buffer format with two >>>> darkness levels. This can be used for two-level dark-on-light displays. >>>> >>>> As the number of bits per pixel is less than eight, this relies on >>>> proper block handling for the calculation of bits per pixel and pitch. >>>> >>>> Signed-off-by: Geert Uytterhoeven >> >>>> --- a/drivers/gpu/drm/drm_fourcc.c >>>> +++ b/drivers/gpu/drm/drm_fourcc.c >>>> @@ -151,6 +151,8 @@ const struct drm_format_info *__drm_format_info(u32 format) >>>> { .format = DRM_FORMAT_C4, .depth = 4, .num_planes = 1, >>>> .char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, >>>> { .format = DRM_FORMAT_C8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 }, >>>> + { .format = DRM_FORMAT_D1, .depth = 1, .num_planes = 1, >>>> + .char_per_block = { 1, }, .block_w = { 8, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, >>>> { .format = DRM_FORMAT_R1, .depth = 1, .num_planes = 1, >>>> .char_per_block = { 1, }, .block_w = { 8, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, >>>> { .format = DRM_FORMAT_R2, .depth = 2, .num_planes = 1, >>>> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h >>>> index 8605a1acc6813e6c..c15c6efcc65e5827 100644 >>>> --- a/include/uapi/drm/drm_fourcc.h >>>> +++ b/include/uapi/drm/drm_fourcc.h >>>> @@ -104,6 +104,9 @@ extern "C" { >>>> #define DRM_FORMAT_C4 fourcc_code('C', '4', ' ', ' ') /* [3:0] C */ >>>> #define DRM_FORMAT_C8 fourcc_code('C', '8', ' ', ' ') /* [7:0] C */ >>>> >>>> +/* 1 bpp Darkness */ >>>> +#define DRM_FORMAT_D1 fourcc_code('D', '1', ' ', ' ') /* [0] D */ >>>> + >>> >>> the same comment here as for C1 and R1 formats, need to specify pixel >>> ordering inside a byte. >> >> Right, will do. > > Btw. does endianess of anything have any effect on these pixel formats? > > That's probably a weird question, but I recall Pixman (the pixel > handling library of the X server nowadays known as Xorg) having pixel > formats where CPU endianess affects whether the first pixel in a byte > is found at the MSB or LSB. Pixman probably has that for hysterical raisins inherited from the X code base. Conceptually, endianness is purely about the order of bytes in words, and is orthogonal to the order in which the bits of a byte/word are numbered. -- Earthling Michel Dänzer | https://redhat.com Libre software enthusiast | Mesa and Xwayland developer