@@ -2955,6 +2955,40 @@ void drm_connector_update_privacy_screen(const struct drm_connector_state *conne
}
EXPORT_SYMBOL(drm_connector_update_privacy_screen);
+/**
+ * drm_connector_hdmi_compute_mode_clock() - Computes the TMDS Character Rate
+ * @mode: Display mode to compute the clock for
+ * @bpc: Bits per character
+ * @fmt: Output Pixel Format used
+ *
+ * Returns the TMDS Character Rate for a given mode, bpc count and output format.
+ *
+ * RETURNS:
+ * The TMDS Character Rate, in Hertz
+ */
+unsigned long long
+drm_connector_hdmi_compute_mode_clock(const struct drm_display_mode *mode,
+ unsigned int bpc,
+ enum hdmi_colorspace fmt)
+{
+ unsigned long long clock = mode->clock * 1000ULL;
+
+ if (fmt == HDMI_COLORSPACE_YUV420)
+ clock = clock / 2;
+
+ if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+ clock = clock * 2;
+
+ if (fmt == HDMI_COLORSPACE_YUV422)
+ bpc = 8;
+
+ clock = clock * bpc;
+ do_div(clock, 8);
+
+ return clock;
+}
+EXPORT_SYMBOL(drm_connector_hdmi_compute_mode_clock);
+
int drm_connector_set_obj_prop(struct drm_mode_object *obj,
struct drm_property *property,
uint64_t value)
@@ -38,6 +38,7 @@ struct drm_connector_helper_funcs;
struct drm_modeset_acquire_ctx;
struct drm_device;
struct drm_crtc;
+struct drm_display_mode;
struct drm_encoder;
struct drm_panel;
struct drm_property;
@@ -2118,6 +2119,10 @@ void drm_connector_attach_privacy_screen_properties(struct drm_connector *conn);
void drm_connector_attach_privacy_screen_provider(
struct drm_connector *connector, struct drm_privacy_screen *priv);
void drm_connector_update_privacy_screen(const struct drm_connector_state *connector_state);
+unsigned long long
+drm_connector_hdmi_compute_mode_clock(const struct drm_display_mode *mode,
+ unsigned int bpc,
+ enum hdmi_colorspace fmt);
/**
* struct drm_tile_group - Tile group metadata
A lot of HDMI drivers have some variation of the formula to calculate the TMDS character rate from a mode, but few of them actually take all parameters into account. Let's create a helper to provide that rate taking all parameters into account. Signed-off-by: Maxime Ripard <mripard@kernel.org> --- drivers/gpu/drm/drm_connector.c | 34 ++++++++++++++++++++++++++++++++++ include/drm/drm_connector.h | 5 +++++ 2 files changed, 39 insertions(+)