[Intel-gfx] [v9][PATCH 03/11] drm/i915/display: Add func to compare hw/sw gamma lut

[Swati Sharma]

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]
    -Dropeed else, character limit and indentation [Uma]
    -Added multi segmented gama mode for icl+ platforms [Uma]

Signed-off-by: Swati Sharma <swati2.sharma at intel.com>
---
 drivers/gpu/drm/i915/display/intel_color.c | 104 +++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_color.h |   6 ++
 2 files changed, 110 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
index dcc65d7..141efb0 100644
--- a/drivers/gpu/drm/i915/display/intel_color.c
+++ b/drivers/gpu/drm/i915/display/intel_color.c
@@ -1470,6 +1470,110 @@ int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
 	return 0;
 }
 
+static inline bool err_check(struct drm_color_lut *sw_lut,
+			     struct drm_color_lut *hw_lut, u32 err)
+{
+	return ((abs((long)hw_lut->red - sw_lut->red)) <= err) &&
+		((abs((long)hw_lut->blue - sw_lut->blue)) <= err) &&
+		((abs((long)hw_lut->green - sw_lut->green)) <= err);
+}
+
+static inline bool intel_color_lut_entry_equal(struct drm_color_lut *sw_lut,
+					       struct drm_color_lut *hw_lut,
+					       int hw_lut_size, u32 err)
+{
+	int i;
+
+	for (i = 0; i < hw_lut_size; i++) {
+		if (!err_check(&hw_lut[i], &sw_lut[i], err))
+			return false;
+	}
+
+	return true;
+}
+
+static inline bool intel_color_lut_entry_equal_multi(struct drm_color_lut *sw_lut,
+						     struct drm_color_lut *hw_lut,
+						     u32 err)
+{
+	int i;
+
+	for (i = 0; i < 9; i++) {
+		if (!err_check(&hw_lut[i], &sw_lut[i], err))
+			return false;
+	}
+
+	for (i = 1; i <  257; i++) {
+		if (!err_check(&hw_lut[8 + i], &sw_lut[i * 8], err))
+			return false;
+	}
+
+	for (i = 0; i < 256; i++) {
+		if (!err_check(&hw_lut[265 + i], &sw_lut[i * 8 * 128], 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 *sw_lut, *hw_lut;
+	int sw_lut_size, hw_lut_size;
+	u32 err;
+
+	if (!blob1 != !blob2)
+		return false;
+
+	if (!blob1)
+		return true;
+
+	sw_lut_size = drm_color_lut_size(blob1);
+	hw_lut_size = 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 (sw_lut_size != hw_lut_size)
+			return false;
+		break;
+	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
+		if ((sw_lut_size != 262145) || (hw_lut_size != 521))
+			return false;
+		break;
+	default:
+		MISSING_CASE(gamma_mode);
+			return false;
+	}
+
+	sw_lut = blob1->data;
+	hw_lut = 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(sw_lut, hw_lut,
+						 hw_lut_size, err))
+			return false;
+		break;
+	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
+		if (!intel_color_lut_entry_equal_multi(sw_lut, hw_lut, 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
--- 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_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__ */
-- 
1.9.1