From nobody Thu Sep 19 23:10:48 2024 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1CD0418410A for ; Fri, 14 Jun 2024 02:46:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.61.82.184 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718333191; cv=none; b=AcyIyNvuvRzggsrMXsaEiDCfpbbwlFKsuw7DcdNk2Dziid57S/twG7nM7v1Oz9t056cesfKgH2XaJ2txd07pFfbw72kWJLcMcBviQF+0h/3bt3geP3cYMG6AU3BV4DV8oA2s48MYUFWUNsxwt+CvPwxob7PEcVC8xNZmqIitZsk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718333191; c=relaxed/simple; bh=ke4iFgPqY/JOg9VDatLm32LPTA+JgSC9vh/gHLk4+sw=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=iKPjF6IE4soTduULNsPXHc7uTFSw7qJ020XjNOQty9ULRHdJiXELgp/5Wcva5dO96zbw5qHCn8ZDeMgOWRIpiWK48Z2PYQNwKo9UD4WBhVGyQX1MV/rdPFXq3aQgBMDBNc293Q83Wh/9f60Te/QYKoPJKZRZay9ZKHV7gdEYVvM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com; spf=pass smtp.mailfrom=mediatek.com; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b=qNDk/dm5; arc=none smtp.client-ip=210.61.82.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mediatek.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="qNDk/dm5" X-UUID: 4adce8fa29f811efa22eafcdcd04c131-20240614 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=vWmVzfOJfIWdePj1eWvkP+831hHcoQ7rXvnybC61XOo=; b=qNDk/dm5YhIv5G+q8WKC/Ql3qsGwpbE+M7GHFYPVsbcsIWw2eSXHQPkf7rJMO3tkRUOkm0ZT52s9FxQRfHt6piaqJjFz6FZX/vJLxS8JxvtznGeuDIj5NC5vuip1vo1bCavnCzTA+C2p3U+AGj0YPYIqp1ZoneHrsTslPiau/n8=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.39,REQID:b44a9200-5344-4830-bac3-b921c02bed55,IP:0,U RL:0,TC:0,Content:0,EDM:-30,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:-30 X-CID-META: VersionHash:393d96e,CLOUDID:e4fe1185-4f93-4875-95e7-8c66ea833d57,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:0,EDM:2,IP:nil,UR L:11|1,File:nil,RT:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES: 1,SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0,ARC:0 X-CID-BVR: 0 X-CID-BAS: 0,_,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_ULN X-UUID: 4adce8fa29f811efa22eafcdcd04c131-20240614 Received: from mtkmbs11n1.mediatek.inc [(172.21.101.185)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 1590546119; Fri, 14 Jun 2024 10:46:25 +0800 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) by MTKMBS09N2.mediatek.inc (172.21.101.94) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.26; Thu, 13 Jun 2024 19:46:24 -0700 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkmbs11n2.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.26 via Frontend Transport; Fri, 14 Jun 2024 10:46:24 +0800 From: Shawn Sung To: Chun-Kuang Hu CC: Philipp Zabel , David Airlie , Daniel Vetter , Matthias Brugger , AngeloGioacchino Del Regno , Bibby Hsieh , CK Hu , "Nancy . Lin" , Sean Paul , Jason Chen , Fei Shao , , , , , Hsiao Chien Sung Subject: [PATCH v9 18/21] drm/mediatek: Support alpha blending in display driver Date: Fri, 14 Jun 2024 10:46:17 +0800 Message-ID: <20240614024620.19011-19-shawn.sung@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20240614024620.19011-1-shawn.sung@mediatek.com> References: <20240614024620.19011-1-shawn.sung@mediatek.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MTK: N Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Hsiao Chien Sung Support "Pre-multiplied" and "None" blend mode on MediaTek's chips by adding correct blend mode property when the planes init. Before this patch, only the "Coverage" mode (default) is supported. For more information, there are three pixel blend modes in DRM driver: "None", "Pre-multiplied", and "Coverage". To understand the difference between these modes, let's take a look at the following two approaches to do alpha blending: 1. Straight: dst.RGB =3D src.RGB * src.A + dst.RGB * (1 - src.A) This is straightforward and easy to understand, when the source layer is compositing with the destination layer, it's alpha will affect the result. This is also known as "post-multiplied", or "Coverage" mode. 2. Pre-multiplied: dst.RGB =3D src.RGB + dst.RGB * (1 - src.A) Since the source RGB have already multiplied its alpha, only destination RGB need to multiply it. This is the "Pre-multiplied" mode in DRM. For the "None" blend mode in DRM, it means the pixel alpha is ignored when compositing the layers, only the constant alpha for the composited layer will take effects. Reviewed-by: CK Hu Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Hsiao Chien Sung --- drivers/gpu/drm/mediatek/mtk_plane.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpu/drm/mediatek/mtk_plane.c b/drivers/gpu/drm/mediate= k/mtk_plane.c index 713e17473930..9762bba23273 100644 --- a/drivers/gpu/drm/mediatek/mtk_plane.c +++ b/drivers/gpu/drm/mediatek/mtk_plane.c @@ -354,6 +354,17 @@ int mtk_plane_init(struct drm_device *dev, struct drm_= plane *plane, DRM_INFO("Create rotation property failed\n"); } =20 + err =3D drm_plane_create_alpha_property(plane); + if (err) + DRM_ERROR("failed to create property: alpha\n"); + + err =3D drm_plane_create_blend_mode_property(plane, + BIT(DRM_MODE_BLEND_PREMULTI) | + BIT(DRM_MODE_BLEND_COVERAGE) | + BIT(DRM_MODE_BLEND_PIXEL_NONE)); + if (err) + DRM_ERROR("failed to create property: blend_mode\n"); + drm_plane_helper_add(plane, &mtk_plane_helper_funcs); =20 return 0; --=20 2.18.0