[PATCH 1/8] drm/display: hdmi: Add common TMDS character rate constants

[Javier Martinez Canillas]

Several DRM drivers already define their own constants for minimum and
maximum TMDS character rates.

By defining common rate constants in a shared header, drivers can just use
them instead of having driver local define macros or use magic numbers.

The values defined in the <drm/display/drm_hdmi_helper.h> header correspond
to maximum TMDS character rates defined by each HDMI specification version:

  - DRM_HDMI_TMDS_CHAR_RATE_MIN:    25 MHz (minimum for all versions)
  - DRM_HDMI_TMDS_CHAR_RATE_MAX_1_0: 165 MHz (HDMI 1.0 maximum)
  - DRM_HDMI_TMDS_CHAR_RATE_MAX_1_3: 340 MHz (HDMI 1.3 maximum)
  - DRM_HDMI_TMDS_CHAR_RATE_MAX_2_0: 600 MHz (HDMI 2.0 maximum)

Suggested-by: Maxime Ripard <mripard@xxxxxxxxxx>
Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
---

 include/drm/display/drm_hdmi_helper.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/drm/display/drm_hdmi_helper.h b/include/drm/display/drm_hdmi_helper.h
index 9c31ed90516b..0ee246ff82e0 100644
--- a/include/drm/display/drm_hdmi_helper.h
+++ b/include/drm/display/drm_hdmi_helper.h
@@ -5,6 +5,12 @@
 
 #include <linux/hdmi.h>
 
+/* HDMI spec TMDS character rate limits (in Hz) */
+#define DRM_HDMI_TMDS_CHAR_RATE_MIN	25000000
+#define DRM_HDMI_TMDS_CHAR_RATE_MAX_1_0	165000000
+#define DRM_HDMI_TMDS_CHAR_RATE_MAX_1_3	340000000
+#define DRM_HDMI_TMDS_CHAR_RATE_MAX_2_0	600000000
+
 struct drm_connector;
 struct drm_connector_state;
 struct drm_display_mode;
-- 
2.54.0