From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751909AbdAaRoa (ORCPT ); Tue, 31 Jan 2017 12:44:30 -0500 Received: from foss.arm.com ([217.140.101.70]:43498 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751925AbdAaRn4 (ORCPT ); Tue, 31 Jan 2017 12:43:56 -0500 From: Brian Starkey To: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org, Jani Nikula , Sean Paul , mihail.atanassov@arm.com, =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Lionel Landwerlin , Daniel Vetter Subject: =?UTF-8?q?=5BPATCH=20v4=5D=20drm/color=3A=20Document=20CTM=20eqations?= Date: Tue, 31 Jan 2017 17:43:48 +0000 Message-Id: <1485884628-4838-1-git-send-email-brian.starkey@arm.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Explicitly state the expected CTM equations in the kerneldoc for the CTM property, and the form of the matrix on struct drm_color_ctm. Cc: Ville Syrjälä Cc: Lionel Landwerlin Cc: Daniel Vetter Signed-off-by: Brian Starkey --- drivers/gpu/drm/drm_color_mgmt.c | 13 +++++++++++++ include/uapi/drm/drm_mode.h | 14 +++++++++++++- 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index 789b4c65cd69..307f7b0545b6 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -62,6 +62,19 @@ * unit/pass-thru matrix should be used. This is generally the driver * boot-up state too. * + * The output vector is related to the input vector as below:: + * + * out[0] = matrix[0] * in[0] + matrix[1] * in[1] + matrix[2] * in[2]; + * out[1] = matrix[3] * in[0] + matrix[4] * in[1] + matrix[5] * in[2]; + * out[2] = matrix[6] * in[0] + matrix[7] * in[1] + matrix[8] * in[2]; + * + * The component order in the input/output vectors is assumed to be + * { R, G, B }. + * + * The color-space of the input vector must not be confused with the + * color-space implied by a framebuffer pixel format, which may be the same + * or different. + * * “GAMMA_LUT”: * Blob property to set the gamma lookup table (LUT) mapping pixel data * after the transformation matrix to data sent to the connector. The diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index ce7efe2e8a5e..3f179b8867e5 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -525,7 +525,19 @@ struct drm_mode_crtc_lut { }; struct drm_color_ctm { - /* Conversion matrix in S31.32 format. */ + /* + * Conversion matrix in row-major form: + * + * | matrix[0] matrix[1] matrix[2] | + * | matrix[3] matrix[4] matrix[5] | + * | matrix[6] matrix[7] matrix[8] | + * + * Each element is in a sign + magnitude format: S31.32, with the sign + * in bit 63, and the magnitude represented as fixed-point 31.32. + * + * i.e. +1.25 = 0x00000001.40000000 + * -1.25 = 0x80000001.40000000 + */ __s64 matrix[9]; }; -- 1.7.9.5