[PATCH 06/10] INTEL_DII: drm: Add helper functions for extended LUT

[Borah, Chaitanya Kumar]

Add helper functions for 64 bit extended LUT

Signed-off-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah at intel.com>
---
 drivers/gpu/drm/drm_color_mgmt.c | 43 ++++++++++++++++++++++++++++++++
 include/drm/drm_color_mgmt.h     | 13 ++++++++++
 2 files changed, 56 insertions(+)

diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c
index 309a5067fb21fe..cdffa99fbcfdfb 100644
--- a/drivers/gpu/drm/drm_color_mgmt.c
+++ b/drivers/gpu/drm/drm_color_mgmt.c
@@ -909,3 +909,46 @@ int drm_color_lut_check(const struct drm_property_blob *lut, u32 tests)
 	return 0;
 }
 EXPORT_SYMBOL(drm_color_lut_check);
+
+/**
+ * drm_color_lut_ext_check - check validity of extended lookup table
+ * @lut: property blob containing extended LUT to check
+ * @tests: bitmask of tests to run
+ *
+ * Helper to check whether a userspace-provided extended lookup table is valid and
+ * satisfies hardware requirements.  Drivers pass a bitmask indicating which of
+ * the tests in &drm_color_lut_tests should be performed.
+ *
+ * Returns 0 on success, -EINVAL on failure.
+ */
+int drm_color_lut_ext_check(const struct drm_property_blob *lut, u32 tests)
+{
+	const struct drm_color_lut_ext *entry;
+	int i;
+
+	if (!lut || !tests)
+		return 0;
+
+	entry = lut->data;
+	for (i = 0; i < drm_color_lut_ext_size(lut); i++) {
+		if (tests & DRM_COLOR_LUT_EQUAL_CHANNELS) {
+			if (entry[i].red != entry[i].blue ||
+			    entry[i].red != entry[i].green) {
+				DRM_DEBUG_KMS("All LUT entries must have equal r/g/b\n");
+				return -EINVAL;
+			}
+		}
+
+		if (i > 0 && tests & DRM_COLOR_LUT_NON_DECREASING) {
+			if (entry[i].red < entry[i - 1].red ||
+			    entry[i].green < entry[i - 1].green ||
+			    entry[i].blue < entry[i - 1].blue) {
+				DRM_DEBUG_KMS("LUT entries must never decrease.\n");
+				return -EINVAL;
+			}
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_color_lut_ext_check);
diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h
index 8599e063974037..58b1fe3d337fe6 100644
--- a/include/drm/drm_color_mgmt.h
+++ b/include/drm/drm_color_mgmt.h
@@ -74,6 +74,18 @@ static inline int drm_color_lut_size(const struct drm_property_blob *blob)
 	return blob->length / sizeof(struct drm_color_lut);
 }
 
+/**
+ * drm_color_lut_ext_size - calculate the number of entries in the extended LUT
+ * @blob: blob containing the LUT
+ *
+ * Returns:
+ * The number of entries in the color LUT stored in @blob.
+ */
+static inline int drm_color_lut_ext_size(const struct drm_property_blob *blob)
+{
+	return blob->length / sizeof(struct drm_color_lut_ext);
+}
+
 int drm_color_create_gamma_mode_property(struct drm_crtc *crtc,
 					 int num_values);
 void drm_crtc_attach_gamma_mode_property(struct drm_crtc *crtc);
@@ -131,4 +143,5 @@ enum drm_color_lut_tests {
 };
 
 int drm_color_lut_check(const struct drm_property_blob *lut, u32 tests);
+int drm_color_lut_ext_check(const struct drm_property_blob *lut, u32 tests);
 #endif
-- 
2.25.1