From patchwork Fri Sep 30 08:39:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 12995049 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2002AC433FE for ; Fri, 30 Sep 2022 08:40:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DE02610E14E; Fri, 30 Sep 2022 08:40:12 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id E93D810E14E for ; Fri, 30 Sep 2022 08:40:02 +0000 (UTC) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 6C3C76BE; Fri, 30 Sep 2022 10:40:01 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1664527201; bh=2F6f2HH2FjofYbN9ozDghNZ7MBQBaFIrtg4BExOSarI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hE/A2mrnRctmk08SsmQksQGZetR4QH26k4+uTwSmrUmEnWnH32+JshTZ1Ob6fXAqW dWbO7e1zycdYuQleBcN+b/4XxKNvjTqtDZzxj4x25cdOHJB8I+AOopxFzlFBIGrVCG PNM/hyrwgT2I9wF2rYYRRjmuunJShVnRr66eqWXg= From: Laurent Pinchart To: dri-devel@lists.freedesktop.org Subject: [PATCH v4 3/4] drm: lcdif: Switch to limited range for RGB to YUV conversion Date: Fri, 30 Sep 2022 11:39:54 +0300 Message-Id: <20220930083955.31580-4-laurent.pinchart@ideasonboard.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220930083955.31580-1-laurent.pinchart@ideasonboard.com> References: <20220930083955.31580-1-laurent.pinchart@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marek Vasut , Peng Fan , Alexander Stein , Kieran Bingham , Liu Ying , Daniel Scally , Robby Cai Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Up to and including v1.3, HDMI supported limited quantization range only for YCbCr. HDMI v1.4 introduced selectable quantization ranges, but this feature isn't supported in the dw-hdmi driver that is used in conjunction with the LCDIF in the i.MX8MP. The HDMI YCbCr output is thus always advertised in the AVI infoframe as limited range. The LCDIF driver, on the other hand, configures the CSC to produce full range YCbCr. This mismatch results in loss of details and incorrect colours. Fix it by switching to limited range YCbCr. The coefficients are copied from drivers/media/platforms/nxp/imx-pxp.c for coherency, as the hardware is most likely identical. Fixes: 9db35bb349a0 ("drm: lcdif: Add support for i.MX8MP LCDIF variant") Signed-off-by: Laurent Pinchart Reviewed-by: Marek Vasut Reviewed-by: Kieran Bingham Reviewed-by: Liu Ying --- Changes since v2: - List floating point coefficient values in comment - Fix typo in the commit message Changes since v1: - Use coefficients from imx-pxp.c --- drivers/gpu/drm/mxsfb/lcdif_kms.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/mxsfb/lcdif_kms.c b/drivers/gpu/drm/mxsfb/lcdif_kms.c index b1092aab1423..9f212e29059b 100644 --- a/drivers/gpu/drm/mxsfb/lcdif_kms.c +++ b/drivers/gpu/drm/mxsfb/lcdif_kms.c @@ -52,16 +52,22 @@ static void lcdif_set_formats(struct lcdif_drm_private *lcdif, writel(DISP_PARA_LINE_PATTERN_UYVY_H, lcdif->base + LCDC_V8_DISP_PARA); - /* CSC: BT.601 Full Range RGB to YCbCr coefficients. */ - writel(CSC0_COEF0_A2(0x096) | CSC0_COEF0_A1(0x04c), + /* + * CSC: BT.601 Limited Range RGB to YCbCr coefficients. + * + * |Y | | 0.2568 0.5041 0.0979| |R| |16 | + * |Cb| = |-0.1482 -0.2910 0.4392| * |G| + |128| + * |Cr| | 0.4392 0.4392 -0.3678| |B| |128| + */ + writel(CSC0_COEF0_A2(0x081) | CSC0_COEF0_A1(0x041), lcdif->base + LCDC_V8_CSC0_COEF0); - writel(CSC0_COEF1_B1(0x7d5) | CSC0_COEF1_A3(0x01d), + writel(CSC0_COEF1_B1(0x7db) | CSC0_COEF1_A3(0x019), lcdif->base + LCDC_V8_CSC0_COEF1); - writel(CSC0_COEF2_B3(0x080) | CSC0_COEF2_B2(0x7ac), + writel(CSC0_COEF2_B3(0x070) | CSC0_COEF2_B2(0x7b6), lcdif->base + LCDC_V8_CSC0_COEF2); - writel(CSC0_COEF3_C2(0x795) | CSC0_COEF3_C1(0x080), + writel(CSC0_COEF3_C2(0x7a2) | CSC0_COEF3_C1(0x070), lcdif->base + LCDC_V8_CSC0_COEF3); - writel(CSC0_COEF4_D1(0x000) | CSC0_COEF4_C3(0x7ec), + writel(CSC0_COEF4_D1(0x010) | CSC0_COEF4_C3(0x7ee), lcdif->base + LCDC_V8_CSC0_COEF4); writel(CSC0_COEF5_D3(0x080) | CSC0_COEF5_D2(0x080), lcdif->base + LCDC_V8_CSC0_COEF5);