From 07c9b8634fb6c5c3fd4cdf363bdf472a365789d0 Mon Sep 17 00:00:00 2001 From: Ankit Nautiyal Date: Fri, 18 Dec 2020 16:07:15 +0530 Subject: drm/dp_helper: Add helpers to configure PCONs RGB-YCbCr Conversion DP Specification for DP2.0 to HDMI2.1 Pcon specifies support for conversion of colorspace from RGB to YCbCr. https://groups.vesa.org/wg/DP/document/previewpdf/15651 This patch adds the relavant registers and helper functions to get the capability and set the color conversion bits for rgb->ycbcr conversion through PCON. v2: As suggested in review comments: -Fixed bug in the check condition in a drm_helper as reported by Dan Carpenter and Kernel test robot. (Dan Carepenter) -Modified the color-conversion cap helper function, to accommodate BT709 and BT2020 colorspace. (Uma Shankar) -Added spec details for the new cap for color conversion. (Uma Shankar) Signed-off-by: Ankit Nautiyal Reviewed-by: Uma Shankar Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20201218103723.30844-8-ankit.k.nautiyal@intel.com --- drivers/gpu/drm/drm_dp_helper.c | 61 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 3b4e96bfb1c3..153086027482 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -949,6 +949,38 @@ bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE] } EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion); +/** + * drm_dp_downstream_rgb_to_ycbcr_conversion() - determine downstream facing port + * RGB->YCbCr conversion capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * @colorspc: Colorspace for which conversion cap is sought + * + * Returns: whether the downstream facing port can convert RGB->YCbCr for a given + * colorspace. + */ +bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + u8 color_spc) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & color_spc; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_rgb_to_ycbcr_conversion); + /** * drm_dp_downstream_mode() - return a mode for downstream facing port * @dev: DRM device @@ -3101,3 +3133,32 @@ int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]) return 0; } EXPORT_SYMBOL(drm_dp_pcon_pps_override_param); + +/* + * drm_dp_pcon_convert_rgb_to_ycbcr() - Configure the PCon to convert RGB to Ycbcr + * @aux: displayPort AUX channel + * @color_spc: Color-space/s for which conversion is to be enabled, 0 for disable. + * + * Returns 0 on success, else returns negative error code. + */ +int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc) +{ + int ret; + u8 buf; + + ret = drm_dp_dpcd_readb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf); + if (ret < 0) + return ret; + + if (color_spc & DP_CONVERSION_RGB_YCBCR_MASK) + buf |= (color_spc & DP_CONVERSION_RGB_YCBCR_MASK); + else + buf &= ~DP_CONVERSION_RGB_YCBCR_MASK; + + ret = drm_dp_dpcd_writeb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf); + if (ret < 0) + return ret; + + return 0; +} +EXPORT_SYMBOL(drm_dp_pcon_convert_rgb_to_ycbcr); -- cgit v1.2.3