Re: [Intel-gfx] [PATCH v5 07/15] drm/dp_helper: Add helpers to configure PCONs RGB-YCbCr Conversion
> -Original Message-
> From: Nautiyal, Ankit K
> Sent: Wednesday, December 16, 2020 11:01 AM
> To: intel-gfx@lists.freedesktop.org
> Cc: dri-de...@lists.freedesktop.org; Shankar, Uma ;
> airl...@linux.ie; jani.nik...@linux.intel.com; ville.syrj...@linux.intel.com;
> Kulkarni, Vandita ; Sharma, Swati2
>
> Subject: [PATCH v5 07/15] 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 accomodate
> BT709 and BT2020 colorspace. (Uma Shankar) -Added spec details for the new
> cap for color conversion. (Uma Shankar)
Looks Good to me.
Reviewed-by: Uma Shankar
> Signed-off-by: Ankit Nautiyal
> ---
> drivers/gpu/drm/drm_dp_helper.c | 61 +
> include/drm/drm_dp_helper.h | 19 +-
> 2 files changed, 79 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c
> b/drivers/gpu/drm/drm_dp_helper.c index 689fd0d5f6c5..9abd65c694ab 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,
> );
> + 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);
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index
> baad87fe6b0a..e096ee98842b 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -432,6 +432,17 @@ struct drm_device;
> # define DP_DS_HDMI_YCBCR444_TO_422_CONV(1 << 3)
> # define DP_DS_HDMI_YCBCR444_TO_420_CONV(1 << 4)
>
> +/*
> + * VESA DP-to-HDMI PCON Specification adds caps for colorspace
> + * conversion in DFP cap DPCD 83h. Sec6.1 Table-3.
> + * Based on the available support the source can enable
> + * color conversion by writing into PROTOCOL_COVERTER_CONTROL_2
> + * DPCD 3052h.
> + */
> +# define DP_DS_HDMI_BT601_RGB_YCBCR_CONV(1 << 5)
> +# define DP_DS_HDMI_BT709_RGB_YCBCR_CONV(1 << 6)
> +# define DP_DS_HDMI_BT2020_RGB_YCBCR_CONV (1 << 7)
> +
[Intel-gfx] [PATCH v5 07/15] 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 accomodate
BT709 and BT2020 colorspace. (Uma Shankar)
-Added spec details for the new cap for color conversion. (Uma Shankar)
Signed-off-by: Ankit Nautiyal
---
drivers/gpu/drm/drm_dp_helper.c | 61 +
include/drm/drm_dp_helper.h | 19 +-
2 files changed, 79 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 689fd0d5f6c5..9abd65c694ab 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, );
+ 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);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index baad87fe6b0a..e096ee98842b 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -432,6 +432,17 @@ struct drm_device;
# define DP_DS_HDMI_YCBCR444_TO_422_CONV(1 << 3)
# define DP_DS_HDMI_YCBCR444_TO_420_CONV(1 << 4)
+/*
+ * VESA DP-to-HDMI PCON Specification adds caps for colorspace
+ * conversion in DFP cap DPCD 83h. Sec6.1 Table-3.
+ * Based on the available support the source can enable
+ * color conversion by writing into PROTOCOL_COVERTER_CONTROL_2
+ * DPCD 3052h.
+ */
+# define DP_DS_HDMI_BT601_RGB_YCBCR_CONV(1 << 5)
+# define DP_DS_HDMI_BT709_RGB_YCBCR_CONV(1 << 6)
+# define DP_DS_HDMI_BT2020_RGB_YCBCR_CONV (1 << 7)
+
#define DP_MAX_DOWNSTREAM_PORTS0x10
/* DP Forward error Correction Registers */
@@ -1207,7 +1218,10 @@ struct drm_device;
# define DP_PCON_ENC_PPS_OVERRIDE_DISABLED 0
# define DP_PCON_ENC_PPS_OVERRIDE_EN_PARAMS 1
# define DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER 2
-
+# define DP_CONVERSION_RGB_YCBCR_MASK (7 << 4)
+# define DP_CONVERSION_BT601_RGB_YCBCR_ENABLE (1 << 4)
+# define DP_CONVERSION_BT709_RGB_YCBCR_ENABLE (1 << 5)
+# define DP_CONVERSION_BT2020_RGB_YCBCR_ENABLE (1 << 6)
/* PCON Downstream HDMI ERROR Status per Lane */
#define DP_PCON_HDMI_ERROR_STATUS_LN0 0x3037
@@ -2167,5 +2181,8
