1 files changed, 102 insertions, 0 deletions
diff --git a/include/video/pixel_format.h b/include/video/pixel_format.h
new file mode 100644
index 000000000000..6874754b0474
--- /dev/null
+++ b/include/video/pixel_format.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef VIDEO_PIXEL_FORMAT_H
+#define VIDEO_PIXEL_FORMAT_H
+
+struct pixel_format {
+	unsigned char bits_per_pixel;
+	bool indexed;
+	union {
+		struct {
+			struct {
+				unsigned char offset;
+				unsigned char length;
+			} alpha, red, green, blue;
+		};
+		struct {
+			unsigned char offset;
+			unsigned char length;
+		} index;
+	};
+};
+
+#define PIXEL_FORMAT_C8 \
+	{ 8, true, { .index = {0, 8}, } }
+
+#define PIXEL_FORMAT_XRGB1555 \
+	{ 16, false, { .alpha = {0, 0}, .red = {10, 5}, .green = {5, 5}, .blue = {0, 5} } }
+
+#define PIXEL_FORMAT_RGB565 \
+	{ 16, false, { .alpha = {0, 0}, .red = {11, 5}, .green = {5, 6}, .blue = {0, 5} } }
+
+#define PIXEL_FORMAT_RGB888 \
+	{ 24, false, { .alpha = {0, 0}, .red = {16, 8}, .green = {8, 8}, .blue = {0, 8} } }
+
+#define PIXEL_FORMAT_XRGB8888 \
+	{ 32, false, { .alpha = {0, 0}, .red = {16, 8}, .green = {8, 8}, .blue = {0, 8} } }
+
+#define PIXEL_FORMAT_XBGR8888 \
+	{ 32, false, { .alpha = {0, 0}, .red = {0, 8}, .green = {8, 8}, .blue = {16, 8} } }
+
+#define PIXEL_FORMAT_XRGB2101010 \
+	{ 32, false, { .alpha = {0, 0}, .red = {20, 10}, .green = {10, 10}, .blue = {0, 10} } }
+
+#define __pixel_format_cmp_field(lhs, rhs, name) \
+	{ \
+		int ret = ((lhs)->name) - ((rhs)->name); \
+		if (ret) \
+			return ret; \
+	}
+
+#define __pixel_format_cmp_bitfield(lhs, rhs, name) \
+	{ \
+		__pixel_format_cmp_field(lhs, rhs, name.offset); \
+		__pixel_format_cmp_field(lhs, rhs, name.length); \
+	}
+
+/**
+ * pixel_format_cmp - Compares two pixel-format descriptions
+ *
+ * @lhs: a pixel-format description
+ * @rhs: a pixel-format description
+ *
+ * Compares two pixel-format descriptions for their order. The semantics
+ * are equivalent to memcmp().
+ *
+ * Returns:
+ * 0 if both arguments describe the same pixel format, less-than-zero if lhs < rhs,
+ * or greater-than-zero if lhs > rhs.
+ */
+static inline int pixel_format_cmp(const struct pixel_format *lhs, const struct pixel_format *rhs)
+{
+	__pixel_format_cmp_field(lhs, rhs, bits_per_pixel);
+	__pixel_format_cmp_field(lhs, rhs, indexed);
+
+	if (lhs->indexed) {
+		__pixel_format_cmp_bitfield(lhs, rhs, index);
+	} else {
+		__pixel_format_cmp_bitfield(lhs, rhs, alpha);
+		__pixel_format_cmp_bitfield(lhs, rhs, red);
+		__pixel_format_cmp_bitfield(lhs, rhs, green);
+		__pixel_format_cmp_bitfield(lhs, rhs, blue);
+	}
+
+	return 0;
+}
+
+/**
+ * pixel_format_equal - Compares two pixel-format descriptions for equality
+ *
+ * @lhs: a pixel-format description
+ * @rhs: a pixel-format description
+ *
+ * Returns:
+ * True if both arguments describe the same pixel format, or false otherwise.
+ */
+static inline bool pixel_format_equal(const struct pixel_format *lhs,
+				      const struct pixel_format *rhs)
+{
+	return !pixel_format_cmp(lhs, rhs);
+}
+
+#endif