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 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 25BCBD116F5 for ; Tue, 2 Dec 2025 06:26:52 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B4AEF10E535; Tue, 2 Dec 2025 06:26:51 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="EI8vyn7L"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8711610E536; Tue, 2 Dec 2025 06:26:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1764656811; x=1796192811; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=dGi7ewIocq9tOZ6lOoWtWKcQo2u0p9cOvO6H946hCeI=; b=EI8vyn7Lwr0O+Fd+H2HzZoM20IRzz6v7MndeovYHgQ9YEB0hQPnh6fhX ql+5DfM5yooqBkPKNfmpDeK1uC1lUV6YP9ioykxO/dzkRzPHvrTour8pJ GNNYGeta7y01/Sej3Zrm9Id8ONvc3+xwEbb8bHt6aS8O6m/V714MdOhuw Vkg6u57DaYGEl4KQKIj9IHmOLPgDt3xv4rbuSZXT1Gay394NEVI9bVoVz /R79ltoVPOOnxhaqQMwFrVp98z+dsHTFTFYg6cFLL9hzV0L41BSGS/HyN lfJpTD5J8VxnJBnHgNItr40gsB1qSxZn/Q/UMdTM/eQ4MNXJI6aVTsxXs g==; X-CSE-ConnectionGUID: HCRgklPhRyWYYH2eFApfFg== X-CSE-MsgGUID: pRJcHZLbQgyox9SY4Iuysw== X-IronPort-AV: E=McAfee;i="6800,10657,11630"; a="66499808" X-IronPort-AV: E=Sophos;i="6.20,242,1758610800"; d="scan'208";a="66499808" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Dec 2025 22:26:50 -0800 X-CSE-ConnectionGUID: KTTH8I6gRia6bqWf5uOeWQ== X-CSE-MsgGUID: NGur8MZARKGJG7rSvGymdQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.20,242,1758610800"; d="scan'208";a="193961065" Received: from srr4-3-linux-106-armuthy.iind.intel.com ([10.190.238.56]) by fmviesa007.fm.intel.com with ESMTP; 01 Dec 2025 22:26:44 -0800 From: Arun R Murthy Date: Tue, 02 Dec 2025 11:56:56 +0530 Subject: [PATCH [RESEND] v9 02/20] drm: Define histogram structures exposed to user MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251202-dpst-v9-2-f2abb2ca2465@intel.com> References: <20251202-dpst-v9-0-f2abb2ca2465@intel.com> In-Reply-To: <20251202-dpst-v9-0-f2abb2ca2465@intel.com> To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Harry Wentland , Leo Li , Rodrigo Siqueira , Alex Deucher , =?utf-8?q?Christian_K=C3=B6nig?= , Jani Nikula , Rodrigo Vivi , Joonas Lahtinen , Tvrtko Ursulin , Lucas De Marchi , =?utf-8?q?Thomas_Hellstr=C3=B6m?= , uma.shankar@intel.com, chaitanya.kumar.borah@intel.com, suraj.kandpal@intel.com Cc: dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, Arun R Murthy X-Mailer: b4 0.15-dev X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" Display Histogram is an array of bins and can be generated in many ways referred to as modes. Ex: HSV max(RGB), Wighted RGB etc. Understanding the histogram data format(Ex: HSV max(RGB)) Histogram is just the pixel count. For a maximum resolution of 10k (10240 x 4320 = 44236800) 25 bits should be sufficient to represent this along with a buffer of 7 bits(future use) u32 is being considered. max(RGB) can be 255 i.e 0xFF 8 bit, considering the most significant 5 bits, hence 32 bins. Below mentioned algorithm illustrates the histogram generation in hardware. hist[32] = {0}; for (i = 0; i < resolution; i++) { bin = max(RGB[i]); bin = bin >> 3; /* consider the most significant bits */ hist[bin]++; } If the entire image is Red color then max(255,0,0) is 255 so the pixel count of each pixels will be placed in the last bin. Hence except hist[31] all other bins will have a value zero. Generated histogram in this case would be hist[32] = {0,0,....44236800} Description of the structures, properties defined are documented in the header file include/uapi/drm/drm_mode.h v8: Added doc for HDR planes, removed reserved variables (Dmitry) Signed-off-by: Arun R Murthy --- include/uapi/drm/drm_mode.h | 65 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index cbbbfc1dfe2b806c641c720b0215e825e350bd03..aa24fef15da708f3e6804d07ffae5b0312dfdce0 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -1545,6 +1545,71 @@ struct drm_mode_closefb { __u32 pad; }; +/** + * enum drm_mode_histogram + * + * @DRM_MODE_HISTOGRAM_HSV_MAX_RGB: + * Maximum resolution at present 10k, 10240x4320 = 44236800 + * can be denoted in 25bits. With an additional 7 bits in buffer each bin + * can be a u32 value. + * For SDL, Maximum value of max(RGB) is 255, so max 255 bins. + * If the most significant 5 bits are considered, then bins = 2^5 + * will be 32 bins. + * For HDR, maximum value of max(RGB) is 65535, so max 65535 bins. + * For illustration consider a full RED image of 10k resolution considering all + * 8 bits histogram would look like hist[255] = {0,0,....44236800} with SDR + * plane similarly with HDR the same would look like hist[65535] = + * {0,0,0,....44236800} + */ +enum drm_mode_histogram { + DRM_MODE_HISTOGRAM_HSV_MAX_RGB = 0x01, +}; + +/** + * struct drm_histogram_caps + * + * @histogram_mode: histogram generation modes, defined in the + * enum drm_mode_histogram + * @bins_count: number of bins for a chosen histogram mode. For illustration + * refer the above defined histogram mode. + */ +struct drm_histogram_caps { + __u32 histogram_mode; + __u32 bins_count; +}; + +/** + * struct drm_histogram_config + * + * @hist_mode_data: address to the histogram mode specific data if any + * @nr_hist_mode_data: number of elements pointed by the address in + * hist_mode_data + * @hist_mode: histogram mode(HSV max(RGB), RGB, LUMA etc) + * @enable: flag to enable/disable histogram + */ +struct drm_histogram_config { + __u64 hist_mode_data; + __u32 nr_hist_mode_data; + enum drm_mode_histogram hist_mode; + bool enable; +}; + +/** + * struct drm_histogram + * + * @config: histogram configuration data pointed by struct drm_histogram_config + * @data_ptr: pointer to the array of histogram. + * Histogram is an array of bins. Data format for each bin depends + * on the histogram mode. Refer to the above histogram modes for + * more information. + * @nr_elements: number of bins in the histogram. + */ +struct drm_histogram { + struct drm_histogram_config config; + __u64 data_ptr; + __u32 nr_elements; +}; + #if defined(__cplusplus) } #endif -- 2.25.1