drm/i915: Gather the HDMI level shifter logic into one place
The knowledge about the HDMI/DVI DDI translation table was scattered
around.
- info->hdmi_level_shift was initialized with 6, the index of the 800
mV, 0dB translation
- A check on the VBT value was done to ensure it wasn't overflowing
the translation table (< 0xC)
- The actual programming was done in intel_ddi.c
As we need to change that knowledge for Broadwell, let's gather
everything into one place.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ce30bb3..0d7e55f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1232,6 +1232,12 @@
};
struct ddi_vbt_port_info {
+ /*
+ * This is an index in the HDMI/DVI DDI buffer translation table.
+ * The special value HDMI_LEVEL_SHIFT_UNKNOWN means the VBT didn't
+ * populate this field.
+ */
+#define HDMI_LEVEL_SHIFT_UNKNOWN 0xff
uint8_t hdmi_level_shift;
uint8_t supports_dvi:1;