This patch adds helper functions for ycbcr HDMI output handling.
These functions provide functionality like:
- getting the highest subsamled ycbcr output
- getting the lowest subsamled ycbcr output
- check if a given source and sink combination can support any YCBCR output
- check if a given source and sink combination can support a particular
YCBCR output
- check if a give mode can be driven in YCBCR420 subsampling.
These functions will be used in next few patches in this
series from I915 driver.
V2: Added YCBCR functions as helpers in DRM layer, instead of
keeping it in I915 layer
Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Jose Abreu <Jose.Abreu@xxxxxxxxxxxx>
Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx>
---
drivers/gpu/drm/drm_edid.c | 2 +-
drivers/gpu/drm/drm_modes.c | 177 ++++++++++++++++++++++++++++++++++++++++++++
include/drm/drm_edid.h | 1 +
include/drm/drm_modes.h | 16 ++++
4 files changed, 195 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 98e00ce..a9d9b1a 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2949,7 +2949,7 @@ u8 drm_match_cea_mode(const struct drm_display_mode *to_match)
}
EXPORT_SYMBOL(drm_match_cea_mode);
-static bool drm_valid_cea_vic(u8 vic)
+bool drm_valid_cea_vic(u8 vic)
{
return vic > 0 && vic < ARRAY_SIZE(edid_cea_modes);
}
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index f2493b9..43c630e 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1576,3 +1576,180 @@ int drm_mode_convert_umode(struct drm_display_mode *out,
out:
return ret;
}
+
+/**
+ * drm_mode_is_420 - if a given videomode can be supported in YCBCR420
+ * output format also
+ *
+ * @connector: drm connector under action.
+ * @mode: video mode to be tested.
+ *
+ * Returns:
+ * true if the mode can support YCBCR420 output
+ * false if not.
+ */
+bool drm_mode_is_420(struct drm_display_info *display,
+ struct drm_display_mode *mode)
+{
+ u8 vic = drm_match_cea_mode(mode);
+ u32 *vcb_map;
+ u8 index;
+
+ if (!drm_valid_cea_vic(vic))
+ return false;
+ /*
+ * ycbcr420_vcb_modes is a fix position 128 bit bitmap. This indicates
+ * support for ycbcr420 output per VIC. Arrangement is bit[n] indicates
+ * if vic[n+1] supports ycbcr420 output.
+ * ycbcr420_vcb_modes[0] = |VIC=32 |VIC=31 |............|VIC=2 |VIC=1 |
+ * ycbcr420_vcb_modes[1] = |VIC=64 |VIC=63 |............|VIC=34|VIC=33|
+ * ycbcr420_vcb_modes[2] = |VIC=96 |VIC=95 |............|VIC=66|VIC=65|
+ * ycbcr420_vcb_modes[3] = |VIC=128|VIC=127|............|VIC=34|VIC=97|
+ */
+ vcb_map = &(display->hdmi.ycbcr420_vcb_modes[(vic - 1) / 32]);
+ index = (vic - 1) % 32;
+ return *vcb_map & (1 << index);
+}
+
+/**
+ * drm_can_support_this_ycbcr_output - can a given source and sink combination
+ * support a particular YCBCR output type.
+ *
+ * @display: sink information.
+ * @mode: video mode from modeset
+ * @type: enum indicating YCBCR output type
+ * @source_outputs: bitmap of source supported HDMI output formats.
+ *
+ * Returns:
+ * true on success.
+ * false on failure.
+ */
+bool drm_can_support_this_ycbcr_output(struct drm_display_info *display,
+ struct drm_display_mode *mode,
+ enum drm_hdmi_output_type type,
+ u32 source_outputs)
+{
+ /* YCBCR420 output support can be per mode basis */
+ if (type == DRM_HDMI_OUTPUT_YCBCR420 &&
+ !drm_mode_is_420(display, mode))
+ return false;
+
+ return display->color_formats & source_outputs & type;
+}
+
+/**
+ * drm_can_support_any_ycbcr_output - can a given source and sink combination
+ * support any YCBCR outputs.
+ *
+ * @display: sink information.
+ * @source_outputs: bitmap of source supported HDMI output formats.
+ *
+ * Returns:
+ * true on success.
+ * false on failure.
+ */
+bool drm_can_support_any_ycbcr_output(struct drm_display_info *display,
+ u32 source_outputs)
+{
+ u32 supported_formats;
+
+ if (!source_outputs || !display->color_formats) {
+ DRM_DEBUG_KMS("Source/Sink doesn't support any output ?\n");
+ return DRM_HDMI_OUTPUT_INVALID;
+ }
+
+ /* Get the common supported fromats between source and sink */
+ supported_formats = display->color_formats & source_outputs;
+ if (!supported_formats || (supported_formats ==
+ DRM_COLOR_FORMAT_RGB444)) {
+ DRM_ERROR("No common YCBCR formats between source and sink\n");
+ return false;
+ }
+
+ DRM_DEBUG_KMS("Src and Sink combination can support YCBCR output\n");
+ return true;
+}
+
+/**
+ * drm_get_highest_quality_ycbcr_supported - get the ycbcr output mode
+ * with highest subsampling rate
+ * @display: struct drm_display_info from current connector
+ * @mode: video mode from modeset
+ * @source_output_map: bitmap of supported HDMI output modes from source
+ *
+ * Finds the best possible ycbcr output mode (based on subsampling), for the
+ * given source and sink combination.
+ *
+ * Returns:
+ * enum corresponding to best output mode on success.
+ * DRM_HDMI_OUTPUT_INVALID on failure.
+ */
+enum drm_hdmi_output_type
+drm_get_highest_quality_ycbcr_supported(struct drm_display_info *display,
+ struct drm_display_mode *mode,
+ u32 source_output_map)
+{
+ enum drm_hdmi_output_type output = DRM_HDMI_OUTPUT_INVALID;
+ u32 supported_formats = source_output_map & display->color_formats;
+
+ /*
+ * Get the ycbcr output with the highest possible subsampling rate.
+ * Preference should go as:
+ * ycbcr 444
+ * ycbcr 422
+ * ycbcr 420
+ */
+ if (supported_formats & DRM_COLOR_FORMAT_YCRCB444)
+ output = DRM_COLOR_FORMAT_YCRCB444;
+ else if (supported_formats & DRM_COLOR_FORMAT_YCRCB422)
+ output = DRM_COLOR_FORMAT_YCRCB422;
+ else if (supported_formats & DRM_COLOR_FORMAT_YCRCB420 &&
+ drm_mode_is_420(display, mode))
+ output = DRM_COLOR_FORMAT_YCRCB420;
+
+ DRM_DEBUG_KMS("Highest subsampled YCBCR mode supported is %s\n",
+ drm_get_hdmi_output_name(supported_formats));
+ return output;
+}
+
+/**
+ * drm_get_lowest_quality_ycbcr_supported - get the ycbcr output mode
+ * with lowest subsampling rate
+ * @display: struct drm_display_info from current connector
+ * @mode: video mode from modeset
+ * @source_output_map: bitmap of supported HDMI output modes from source
+ *
+ * Finds the lowest possible ycbcr output mode (based on subsampling), for the
+ * given source and sink combination.
+ *
+ * Returns:
+ * enum corresponding to best output mode on success.
+ * DRM_HDMI_OUTPUT_INVALID on failure.
+ */
+enum drm_hdmi_output_type
+drm_get_lowest_quality_ycbcr_supported(struct drm_display_info *display,
+ struct drm_display_mode *mode,
+ u32 source_output_map)
+{
+ enum drm_hdmi_output_type output = DRM_HDMI_OUTPUT_INVALID;
+ u32 supported_formats = source_output_map & display->color_formats;
+
+ /*
+ * Get the ycbcr output with the lowest possible subsampling rate.
+ * Preference should go as:
+ * ycbcr 420
+ * ycbcr 422
+ * ycbcr 444
+ */
+ if (supported_formats & DRM_COLOR_FORMAT_YCRCB420 &&
+ drm_mode_is_420(display, mode))
+ output = DRM_HDMI_OUTPUT_YCBCR420;
+ else if (display->color_formats & DRM_COLOR_FORMAT_YCRCB422)
+ output = DRM_HDMI_OUTPUT_YCBCR422;
+ else if (display->color_formats & DRM_COLOR_FORMAT_YCRCB444)
+ output = DRM_HDMI_OUTPUT_YCBCR420;
+
+ DRM_DEBUG_KMS("Lowest subsampled YCBCR mode supported is %s\n",
+ drm_get_hdmi_output_name(supported_formats));
+ return output;
+}
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 8980366..d025d56 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -468,6 +468,7 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid);
u8 drm_match_cea_mode(const struct drm_display_mode *to_match);
enum hdmi_picture_aspect drm_get_cea_aspect_ratio(const u8 video_code);
+bool drm_valid_cea_vic(u8 vic);
bool drm_detect_hdmi_monitor(struct edid *edid);
bool drm_detect_monitor_audio(struct edid *edid);
bool drm_rgb_quant_range_selectable(struct edid *edid);
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index 6dd34280..fc1aec0 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -433,6 +433,22 @@ int drm_mode_convert_umode(struct drm_display_mode *out,
const struct drm_mode_modeinfo *in);
void drm_mode_probed_add(struct drm_connector *connector, struct drm_display_mode *mode);
void drm_mode_debug_printmodeline(const struct drm_display_mode *mode);
+bool drm_mode_is_420(struct drm_display_info *display,
+ struct drm_display_mode *mode);
+bool drm_can_support_this_ycbcr_output(struct drm_display_info *display,
+ struct drm_display_mode *mode,
+ enum drm_hdmi_output_type type,
+ u32 source_outputs);
+bool drm_can_support_any_ycbcr_output(struct drm_display_info *display,
+ u32 source_outputs);
+enum drm_hdmi_output_type
+drm_get_highest_quality_ycbcr_supported(struct drm_display_info *display,
+ struct drm_display_mode *mode,
+ u32 source_output_map);
+enum drm_hdmi_output_type
+drm_get_lowest_quality_ycbcr_supported(struct drm_display_info *display,
+ struct drm_display_mode *mode,
+ u32 source_output_map);
struct drm_display_mode *drm_cvt_mode(struct drm_device *dev,
int hdisplay, int vdisplay, int vrefresh,
--
2.7.4
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