drm/i915: Add "Automatic" mode for the "Broadcast RGB" property

Add a new "Automatic" mode to the "Broadcast RGB" range property.
When selected the driver automagically selects between full range and
limited range output.

Based on CEA-861 [1] guidelines, limited range output is selected if the
mode is a CEA mode, except 640x480. Otherwise full range output is used.
Additionally DVI monitors should most likely default to full range
always.

As per DP1.2a [2] DisplayPort should always use full range for 18bpp, and
otherwise will follow CEA-861 rules.

NOTE: The default value for the property will now be "Automatic"
so some people may be affected in case they're relying on the
current full range default.

[1] CEA-861-E - 5.1 Default Encoding Parameters
[2] VESA DisplayPort Ver.1.2a - 5.1.1.1 Video Colorimetry

v2: Use has_hdmi_sink to check if a HDMI monitor is present
v3: Add information about relevant spec chapters

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Ville Syrjälä
2013-01-17 16:31:29 +02:00
committed by Daniel Vetter
parent 3685a8f38f
commit 55bc60db59
6 changed files with 93 additions and 17 deletions

View File

@@ -1811,5 +1811,9 @@ __i915_write(64, q)
#define POSTING_READ(reg) (void)I915_READ_NOTRACE(reg)
#define POSTING_READ16(reg) (void)I915_READ16_NOTRACE(reg)
/* "Broadcast RGB" property */
#define INTEL_BROADCAST_RGB_AUTO 0
#define INTEL_BROADCAST_RGB_FULL 1
#define INTEL_BROADCAST_RGB_LIMITED 2
#endif