[RFC PATCH v2 13/20] drm: Add helper to extract a LUT entry from either 16-bit or 32-bit LUT

From: Ariel D'Alessandro <[email protected]>

Add a common helper to ease extracting a 32-bit LUT entry from either
16-bit or 32-bit LUT entry. This is handy for code that needs to handle
both bit widths.

Signed-off-by: Ariel D'Alessandro <[email protected]>
Co-developed-by: Nícolas F. R. A. Prado <[email protected]>
Signed-off-by: Nícolas F. R. A. Prado <[email protected]>
---
 include/drm/drm_color_mgmt.h | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h
index 51279267ed3f..3d0117aae342 100644
--- a/include/drm/drm_color_mgmt.h
+++ b/include/drm/drm_color_mgmt.h
@@ -66,6 +66,33 @@ static inline u32 drm_color_lut32_extract(u32 user_input, int bit_precision)
 				     (1ULL << 32) - 1);
 }
 
+/**
+ * drm_color_lut_to_lut32 - Copy LUT entry contents to 32-bit channel color LUT
+ *
+ * @dest: The destination 32-bit per channel color LUT entry
+ * @src: The source array of LUT entries (16-bit or 32-bit depending on @bits32)
+ * @index: LUT entry array index
+ * @bits32: Boolean indicating the source LUT entry bit-witdh
+ *
+ * Copy the contents of a LUT entry from the source array, to a 32-bit channel
+ * color LUT. The source array of LUT entries can be 16-bit or 32-bit width
+ * depending on the @bits32 boolean argument.
+ */
+static inline void drm_color_lut_to_lut32(struct drm_color_lut32 *dest,
+					  void *src, int index, bool bits32)
+{
+	if (bits32) {
+		*dest = ((struct drm_color_lut32 *)src)[index];
+	} else {
+		struct drm_color_lut *lut =
+			&((struct drm_color_lut *)src)[index];
+		dest->red = lut->red;
+		dest->green = lut->green;
+		dest->blue = lut->blue;
+		dest->reserved = lut->reserved;
+	}
+}
+
 /**
  * drm_color_ctm_to_ctm_3x4 - Copy CTM matrix contents to 3x4 dimensions matrix
  *
-- 
2.53.0