Most drivers supporting the HDMI scrambling seem to have the HDMI 1.4 maximum frequency open-coded, and a function to test whether a display mode is above that threshold to control whether or not scrambling should be enabled.
Let's create a common define and helper for drivers to reuse.
Signed-off-by: Maxime Ripard maxime@cerno.tech --- include/drm/drm_modes.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h index 29ba4adf0c53..3bbf98ae59ae 100644 --- a/include/drm/drm_modes.h +++ b/include/drm/drm_modes.h @@ -424,6 +424,26 @@ static inline bool drm_mode_is_stereo(const struct drm_display_mode *mode) return mode->flags & DRM_MODE_FLAG_3D_MASK; }
+/** + * drm_mode_hdmi_requires_scrambling - Checks if a mode requires HDMI Scrambling + * @mode: DRM display mode + * @bpc: Pixels bit depth + * + * Checks if a given display mode requires the scrambling to be enabled. + * + * Returns: + * A boolean stating whether it's required or not. + */ +static inline bool +drm_mode_hdmi_requires_scrambling(const struct drm_display_mode *mode, + unsigned char bpc) +{ + unsigned long long clock = mode->crtc_clock * bpc; + do_div(clock, 8); + + return mode->clock > 340000; +} + struct drm_connector; struct drm_cmdline_mode;