[Intel-gfx] [PATCH 1/3] drm/fourcc: Add 64 bpp half float formats

[Kevin Strasser]

Add 64 bpp 16:16:16:16 half float pixel formats. Each 16 bit component is
formatted in IEEE-754 half-precision float (binary16) 1:5:10
MSb-sign:exponent:fraction form.

An 'is_fp' attribute is added to drm_format_info so that drivers can easily
distinguish these formats from those that might contain uint pixel data.

This patch attempts to address the feedback provided when 2 of these
formats were previosly proposed:
  https://patchwork.kernel.org/patch/10072545/

Signed-off-by: Kevin Strasser <kevin.strasser at intel.com>
Cc: Tina Zhang <tina.zhang at intel.com>
Cc: Uma Shankar <uma.shankar at intel.com>
Cc: Shashank Sharma <shashank.sharma at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: dri-devel at lists.freedesktop.org
---
 drivers/gpu/drm/drm_fourcc.c  | 4 ++++
 include/drm/drm_fourcc.h      | 3 +++
 include/uapi/drm/drm_fourcc.h | 6 ++++++
 3 files changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index f523948..a7b969a 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -198,6 +198,10 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		{ .format = DRM_FORMAT_ABGR8888,	.depth = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true },
 		{ .format = DRM_FORMAT_RGBA8888,	.depth = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true },
 		{ .format = DRM_FORMAT_BGRA8888,	.depth = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true },
+		{ .format = DRM_FORMAT_XRGB16161616H,	.depth = 48, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .is_fp = true },
+		{ .format = DRM_FORMAT_XBGR16161616H,	.depth = 48, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .is_fp = true },
+		{ .format = DRM_FORMAT_ARGB16161616H,	.depth = 64, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true, .is_fp = true },
+		{ .format = DRM_FORMAT_ABGR16161616H,	.depth = 64, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true, .is_fp = true },
 		{ .format = DRM_FORMAT_RGB888_A8,	.depth = 32, .num_planes = 2, .cpp = { 3, 1, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true },
 		{ .format = DRM_FORMAT_BGR888_A8,	.depth = 32, .num_planes = 2, .cpp = { 3, 1, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true },
 		{ .format = DRM_FORMAT_XRGB8888_A8,	.depth = 32, .num_planes = 2, .cpp = { 4, 1, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true },
diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
index bcb389f..2c5aa19 100644
--- a/include/drm/drm_fourcc.h
+++ b/include/drm/drm_fourcc.h
@@ -133,6 +133,9 @@ struct drm_format_info {
 
 	/** @is_yuv: Is it a YUV format? */
 	bool is_yuv;
+
+	/** @is_fp: Is it a floating point format? */
+	bool is_fp;
 };
 
 /**
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index e7e48f1f..530bce4 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -144,6 +144,12 @@ extern "C" {
 #define DRM_FORMAT_RGBA1010102	fourcc_code('R', 'A', '3', '0') /* [31:0] R:G:B:A 10:10:10:2 little endian */
 #define DRM_FORMAT_BGRA1010102	fourcc_code('B', 'A', '3', '0') /* [31:0] B:G:R:A 10:10:10:2 little endian */
 
+/* 64 bpp RGB IEEE-754 half-precision float (binary16) */
+#define DRM_FORMAT_XBGR16161616H fourcc_code('X', 'B', '4', 'H') /* [63:0] x:B:G:R 16:16:16:16 little endian */
+#define DRM_FORMAT_ABGR16161616H fourcc_code('A', 'B', '4', 'H') /* [63:0] A:B:G:R 16:16:16:16 little endian */
+#define DRM_FORMAT_XRGB16161616H fourcc_code('X', 'R', '4', 'H') /* [63:0] x:R:G:B 16:16:16:16 little endian */
+#define DRM_FORMAT_ARGB16161616H fourcc_code('A', 'R', '4', 'H') /* [63:0] A:R:G:B 16:16:16:16 little endian */
+
 /* packed YCbCr */
 #define DRM_FORMAT_YUYV		fourcc_code('Y', 'U', 'Y', 'V') /* [31:0] Cr0:Y1:Cb0:Y0 8:8:8:8 little endian */
 #define DRM_FORMAT_YVYU		fourcc_code('Y', 'V', 'Y', 'U') /* [31:0] Cb0:Y1:Cr0:Y0 8:8:8:8 little endian */
-- 
2.7.4