drm/i915/display: Add func to compare hw/sw gamma lut

Add func intel_color_lut_equal() to compare hw/sw gamma
lut values. Since hw/sw gamma lut sizes and lut entries comparison
will be different for different gamma modes, add gamma mode dependent
checks.

v3:  -Rebase
v4:  -Renamed intel_compare_color_lut() to intel_color_lut_equal() [Jani]
     -Added the default label above the correct label [Jani]
     -Corrected smatch warn "variable dereferenced before check"
      [Dan Carpenter]
v5:  -Added condition (!blob1 && !blob2) return true [Jani]
v6:  -Made patch11 as patch3 [Jani]
v8:  -Split patch 3 into 4 patches
     -Optimized blob check condition [Ville]
v9:  -Exclude spilt gamma mode (bdw and ivb platforms)
      as there is exception in way gamma values are written in
      hardware [Ville]
     -Added exception made in commit [Uma]
     -Dropped else, character limit and indentation [Uma]
     -Added multi segmented gama mode for icl+ platforms [Uma]
v10: -Dropped multi segmented mode for icl+ platforms [Jani]
     -Removed references of sw and hw state in compare code [Jani]
     -Dropped inline from func [Jani]

Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1567538578-4489-4-git-send-email-swati2.sharma@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
index b5c0c65..1ab561d 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_color.c
+++ b/drivers/gpu/drm/i915/display/intel_color.c
@@ -1431,6 +1431,78 @@ int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
        return 0;
 }
 
+static bool err_check(struct drm_color_lut *lut1,
+                     struct drm_color_lut *lut2, u32 err)
+{
+       return ((abs((long)lut2->red - lut1->red)) <= err) &&
+               ((abs((long)lut2->blue - lut1->blue)) <= err) &&
+               ((abs((long)lut2->green - lut1->green)) <= err);
+}
+
+static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
+                                       struct drm_color_lut *lut2,
+                                       int lut_size, u32 err)
+{
+       int i;
+
+       for (i = 0; i < lut_size; i++) {
+               if (!err_check(&lut1[i], &lut2[i], err))
+                       return false;
+       }
+
+       return true;
+}
+
+bool intel_color_lut_equal(struct drm_property_blob *blob1,
+                          struct drm_property_blob *blob2,
+                          u32 gamma_mode, u32 bit_precision)
+{
+       struct drm_color_lut *lut1, *lut2;
+       int lut_size1, lut_size2;
+       u32 err;
+
+       if (!blob1 != !blob2)
+               return false;
+
+       if (!blob1)
+               return true;
+
+       lut_size1 = drm_color_lut_size(blob1);
+       lut_size2 = drm_color_lut_size(blob2);
+
+       /* check sw and hw lut size */
+       switch (gamma_mode) {
+       case GAMMA_MODE_MODE_8BIT:
+       case GAMMA_MODE_MODE_10BIT:
+               if (lut_size1 != lut_size2)
+                       return false;
+               break;
+       default:
+               MISSING_CASE(gamma_mode);
+                       return false;
+       }
+
+       lut1 = blob1->data;
+       lut2 = blob2->data;
+
+       err = 0xffff >> bit_precision;
+
+       /* check sw and hw lut entry to be equal */
+       switch (gamma_mode) {
+       case GAMMA_MODE_MODE_8BIT:
+       case GAMMA_MODE_MODE_10BIT:
+               if (!intel_color_lut_entry_equal(lut1, lut2,
+                                                lut_size2, err))
+                       return false;
+               break;
+       default:
+               MISSING_CASE(gamma_mode);
+                       return false;
+       }
+
+       return true;
+}
+
 void intel_color_init(struct intel_crtc *crtc)
 {
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);

diff --git a/drivers/gpu/drm/i915/display/intel_color.h b/drivers/gpu/drm/i915/display/intel_color.h
index 0226d3a..173727a 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_color.h
+++ b/drivers/gpu/drm/i915/display/intel_color.h
@@ -6,8 +6,11 @@
 #ifndef __INTEL_COLOR_H__
 #define __INTEL_COLOR_H__
 
+#include <linux/types.h>
+
 struct intel_crtc_state;
 struct intel_crtc;
+struct drm_property_blob;
 
 void intel_color_init(struct intel_crtc *crtc);
 int intel_color_check(struct intel_crtc_state *crtc_state);
@@ -15,5 +18,8 @@ void intel_color_commit(const struct intel_crtc_state *crtc_state);
 void intel_color_load_luts(const struct intel_crtc_state *crtc_state);
 void intel_color_get_config(struct intel_crtc_state *crtc_state);
 int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state);
+bool intel_color_lut_equal(struct drm_property_blob *blob1,
+                          struct drm_property_blob *blob2,
+                          u32 gamma_mode, u32 bit_precision);
 
 #endif /* __INTEL_COLOR_H__ */