drm/i915/dp: Track the pipe and link bpp limits separately

A follow-up patch will need to limit the output link bpp both in the
non-DSC and DSC configuration, so track the pipe and link bpp limits
separately in the link_config_limits struct.

Use .4 fixed point format for link bpp matching the 1/16 bpp granularity
in DSC mode and for now keep this limit matching the pipe bpp limit.

v2: (Jani)
- Add to_bpp_int(), to_bpp_x16() helpers instead of opencoding them.
- Rename link_config_limits::link.min/max_bpp to min/max_bpp_x16.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230921195159.2646027-3-imre.deak@intel.com

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index b34ddc9c352a..98c60ab6e182 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -26,7 +26,14 @@ struct intel_encoder;
 struct link_config_limits {
 	int min_rate, max_rate;
 	int min_lane_count, max_lane_count;
-	int min_bpp, max_bpp;
+	struct {
+		/* Uncompressed DSC input or link output bpp in 1 bpp units */
+		int min_bpp, max_bpp;
+	} pipe;
+	struct {
+		/* Compressed or uncompressed link output bpp in 1/16 bpp units */
+		int min_bpp_x16, max_bpp_x16;
+	} link;
 };
 
 void intel_edp_fixup_vbt_bpp(struct intel_encoder *encoder, int pipe_bpp);