[PATCH v2 0/5] Centralize format information

[PATCH v2 0/5] Centralize format information

[Laurent Pinchart]

Hello,

Various pieces of information about DRM formats (number of planes, color
depth, chroma subsampling, ...) are scattered across different helper
functions in the DRM core. Callers of those functions often need to access
more than a single parameter of the format, leading to inefficiencies due to
multiple lookups.

This patch series addresses this issue by centralizing all format information
in a single data structure (2/5). It reimplements the existing format helper
functions based on that structure (3/5) and converts the DRM core code to use
the new structure (4/5).

The new API is also useful for drivers as shown by the "[PATCH v2 00/20] OMAP
DRM fixes and improvements" patch series posted yesterday.

Changes since v1:

- Move format-related helpers to drm_fourcc.c (1/5)
- Use named initializers for the formats array (2/5)
- WARN when calling drm_format_info() for an unsupported format (5/5)
- Don't drop the drm_format_plane_width() and drm_format_plane_height()
  helpers

Laurent Pinchart (5):
  drm: Move format-related helpers to drm_fourcc.c
  drm: Centralize format information
  drm: Implement the drm_format_*() helpers as drm_format_info()
    wrappers
  drm: Use drm_format_info() in DRM core code
  drm: WARN when calling drm_format_info() for an unsupported format

 Documentation/DocBook/gpu.tmpl      |   5 +
 drivers/gpu/drm/Makefile            |   2 +-
 drivers/gpu/drm/drm_crtc.c          | 389 ++----------------------------------
 drivers/gpu/drm/drm_fb_cma_helper.c |  23 ++-
 drivers/gpu/drm/drm_fourcc.c        | 308 ++++++++++++++++++++++++++++
 include/drm/drmP.h                  |   1 +
 include/drm/drm_crtc.h              |   9 -
 include/drm/drm_fourcc.h            |  59 ++++++
 8 files changed, 399 insertions(+), 397 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_fourcc.c
 create mode 100644 include/drm/drm_fourcc.h

-- 
Regards,

Laurent Pinchart

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dri-devel@lists.freedesktop.org
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[PATCH v2 1/5] drm: Move format-related helpers to drm_fourcc.c

[Laurent Pinchart]

The drm_crtc.c file is a mess, making the ABI documentation confusing
since all functions are in the same bag. Split the format-related
helpers to a new drm_fourcc.c file.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 Documentation/DocBook/gpu.tmpl |   5 +
 drivers/gpu/drm/Makefile       |   2 +-
 drivers/gpu/drm/drm_crtc.c     | 289 -------------------------------------
 drivers/gpu/drm/drm_fourcc.c   | 320 +++++++++++++++++++++++++++++++++++++++++
 include/drm/drmP.h             |   1 +
 include/drm/drm_crtc.h         |   9 --
 include/drm/drm_fourcc.h       |  37 +++++
 7 files changed, 364 insertions(+), 299 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_fourcc.c
 create mode 100644 include/drm/drm_fourcc.h

diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl
index 7586bf75f62e..d32363cb1ff1 100644
--- a/Documentation/DocBook/gpu.tmpl
+++ b/Documentation/DocBook/gpu.tmpl
@@ -1656,6 +1656,11 @@ void intel_crt_init(struct drm_device *dev)
 !Edrivers/gpu/drm/drm_rect.c
     </sect2>
     <sect2>
+      <title>Formats Utilities Reference</title>
+!Iinclude/drm/drm_fourcc.h
+!Edrivers/gpu/drm/drm_fourcc.c
+    </sect2>
+    <sect2>
       <title>Flip-work Helper Reference</title>
 !Pinclude/drm/drm_flip_work.h flip utils
 !Iinclude/drm/drm_flip_work.h
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index be43afb08c69..aa24af35c068 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -8,7 +8,7 @@ drm-y       :=	drm_auth.o drm_bufs.o drm_cache.o \
 		drm_lock.o drm_memory.o drm_drv.o drm_vm.o \
 		drm_scatter.o drm_pci.o \
 		drm_platform.o drm_sysfs.o drm_hashtab.o drm_mm.o \
-		drm_crtc.o drm_modes.o drm_edid.o \
+		drm_crtc.o drm_fourcc.o drm_modes.o drm_edid.o \
 		drm_info.o drm_debugfs.o drm_encoder_slave.o \
 		drm_trace_points.o drm_global.o drm_prime.o \
 		drm_rect.o drm_vma_manager.o drm_flip_work.o \
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 0e3cc66aa8b7..e5369529af06 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -239,37 +239,6 @@ const char *drm_get_subpixel_order_name(enum subpixel_order order)
 }
 EXPORT_SYMBOL(drm_get_subpixel_order_name);
 
-static char printable_char(int c)
-{
-	return isascii(c) && isprint(c) ? c : '?';
-}
-
-/**
- * drm_get_format_name - return a string for drm fourcc format
- * @format: format to compute name of
- *
- * Note that the buffer used by this function is globally shared and owned by
- * the function itself.
- *
- * FIXME: This isn't really multithreading safe.
- */
-const char *drm_get_format_name(uint32_t format)
-{
-	static char buf[32];
-
-	snprintf(buf, sizeof(buf),
-		 "%c%c%c%c %s-endian (0x%08x)",
-		 printable_char(format & 0xff),
-		 printable_char((format >> 8) & 0xff),
-		 printable_char((format >> 16) & 0xff),
-		 printable_char((format >> 24) & 0x7f),
-		 format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
-		 format);
-
-	return buf;
-}
-EXPORT_SYMBOL(drm_get_format_name);
-
 /*
  * Internal function to assign a slot in the object idr and optionally
  * register the object into the idr.
@@ -5544,264 +5513,6 @@ int drm_mode_destroy_dumb_ioctl(struct drm_device *dev,
 }
 
 /**
- * drm_fb_get_bpp_depth - get the bpp/depth values for format
- * @format: pixel format (DRM_FORMAT_*)
- * @depth: storage for the depth value
- * @bpp: storage for the bpp value
- *
- * This only supports RGB formats here for compat with code that doesn't use
- * pixel formats directly yet.
- */
-void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
-			  int *bpp)
-{
-	switch (format) {
-	case DRM_FORMAT_C8:
-	case DRM_FORMAT_RGB332:
-	case DRM_FORMAT_BGR233:
-		*depth = 8;
-		*bpp = 8;
-		break;
-	case DRM_FORMAT_XRGB1555:
-	case DRM_FORMAT_XBGR1555:
-	case DRM_FORMAT_RGBX5551:
-	case DRM_FORMAT_BGRX5551:
-	case DRM_FORMAT_ARGB1555:
-	case DRM_FORMAT_ABGR1555:
-	case DRM_FORMAT_RGBA5551:
-	case DRM_FORMAT_BGRA5551:
-		*depth = 15;
-		*bpp = 16;
-		break;
-	case DRM_FORMAT_RGB565:
-	case DRM_FORMAT_BGR565:
-		*depth = 16;
-		*bpp = 16;
-		break;
-	case DRM_FORMAT_RGB888:
-	case DRM_FORMAT_BGR888:
-		*depth = 24;
-		*bpp = 24;
-		break;
-	case DRM_FORMAT_XRGB8888:
-	case DRM_FORMAT_XBGR8888:
-	case DRM_FORMAT_RGBX8888:
-	case DRM_FORMAT_BGRX8888:
-		*depth = 24;
-		*bpp = 32;
-		break;
-	case DRM_FORMAT_XRGB2101010:
-	case DRM_FORMAT_XBGR2101010:
-	case DRM_FORMAT_RGBX1010102:
-	case DRM_FORMAT_BGRX1010102:
-	case DRM_FORMAT_ARGB2101010:
-	case DRM_FORMAT_ABGR2101010:
-	case DRM_FORMAT_RGBA1010102:
-	case DRM_FORMAT_BGRA1010102:
-		*depth = 30;
-		*bpp = 32;
-		break;
-	case DRM_FORMAT_ARGB8888:
-	case DRM_FORMAT_ABGR8888:
-	case DRM_FORMAT_RGBA8888:
-	case DRM_FORMAT_BGRA8888:
-		*depth = 32;
-		*bpp = 32;
-		break;
-	default:
-		DRM_DEBUG_KMS("unsupported pixel format %s\n",
-			      drm_get_format_name(format));
-		*depth = 0;
-		*bpp = 0;
-		break;
-	}
-}
-EXPORT_SYMBOL(drm_fb_get_bpp_depth);
-
-/**
- * drm_format_num_planes - get the number of planes for format
- * @format: pixel format (DRM_FORMAT_*)
- *
- * Returns:
- * The number of planes used by the specified pixel format.
- */
-int drm_format_num_planes(uint32_t format)
-{
-	switch (format) {
-	case DRM_FORMAT_YUV410:
-	case DRM_FORMAT_YVU410:
-	case DRM_FORMAT_YUV411:
-	case DRM_FORMAT_YVU411:
-	case DRM_FORMAT_YUV420:
-	case DRM_FORMAT_YVU420:
-	case DRM_FORMAT_YUV422:
-	case DRM_FORMAT_YVU422:
-	case DRM_FORMAT_YUV444:
-	case DRM_FORMAT_YVU444:
-		return 3;
-	case DRM_FORMAT_NV12:
-	case DRM_FORMAT_NV21:
-	case DRM_FORMAT_NV16:
-	case DRM_FORMAT_NV61:
-	case DRM_FORMAT_NV24:
-	case DRM_FORMAT_NV42:
-		return 2;
-	default:
-		return 1;
-	}
-}
-EXPORT_SYMBOL(drm_format_num_planes);
-
-/**
- * drm_format_plane_cpp - determine the bytes per pixel value
- * @format: pixel format (DRM_FORMAT_*)
- * @plane: plane index
- *
- * Returns:
- * The bytes per pixel value for the specified plane.
- */
-int drm_format_plane_cpp(uint32_t format, int plane)
-{
-	unsigned int depth;
-	int bpp;
-
-	if (plane >= drm_format_num_planes(format))
-		return 0;
-
-	switch (format) {
-	case DRM_FORMAT_YUYV:
-	case DRM_FORMAT_YVYU:
-	case DRM_FORMAT_UYVY:
-	case DRM_FORMAT_VYUY:
-		return 2;
-	case DRM_FORMAT_NV12:
-	case DRM_FORMAT_NV21:
-	case DRM_FORMAT_NV16:
-	case DRM_FORMAT_NV61:
-	case DRM_FORMAT_NV24:
-	case DRM_FORMAT_NV42:
-		return plane ? 2 : 1;
-	case DRM_FORMAT_YUV410:
-	case DRM_FORMAT_YVU410:
-	case DRM_FORMAT_YUV411:
-	case DRM_FORMAT_YVU411:
-	case DRM_FORMAT_YUV420:
-	case DRM_FORMAT_YVU420:
-	case DRM_FORMAT_YUV422:
-	case DRM_FORMAT_YVU422:
-	case DRM_FORMAT_YUV444:
-	case DRM_FORMAT_YVU444:
-		return 1;
-	default:
-		drm_fb_get_bpp_depth(format, &depth, &bpp);
-		return bpp >> 3;
-	}
-}
-EXPORT_SYMBOL(drm_format_plane_cpp);
-
-/**
- * drm_format_horz_chroma_subsampling - get the horizontal chroma subsampling factor
- * @format: pixel format (DRM_FORMAT_*)
- *
- * Returns:
- * The horizontal chroma subsampling factor for the
- * specified pixel format.
- */
-int drm_format_horz_chroma_subsampling(uint32_t format)
-{
-	switch (format) {
-	case DRM_FORMAT_YUV411:
-	case DRM_FORMAT_YVU411:
-	case DRM_FORMAT_YUV410:
-	case DRM_FORMAT_YVU410:
-		return 4;
-	case DRM_FORMAT_YUYV:
-	case DRM_FORMAT_YVYU:
-	case DRM_FORMAT_UYVY:
-	case DRM_FORMAT_VYUY:
-	case DRM_FORMAT_NV12:
-	case DRM_FORMAT_NV21:
-	case DRM_FORMAT_NV16:
-	case DRM_FORMAT_NV61:
-	case DRM_FORMAT_YUV422:
-	case DRM_FORMAT_YVU422:
-	case DRM_FORMAT_YUV420:
-	case DRM_FORMAT_YVU420:
-		return 2;
-	default:
-		return 1;
-	}
-}
-EXPORT_SYMBOL(drm_format_horz_chroma_subsampling);
-
-/**
- * drm_format_vert_chroma_subsampling - get the vertical chroma subsampling factor
- * @format: pixel format (DRM_FORMAT_*)
- *
- * Returns:
- * The vertical chroma subsampling factor for the
- * specified pixel format.
- */
-int drm_format_vert_chroma_subsampling(uint32_t format)
-{
-	switch (format) {
-	case DRM_FORMAT_YUV410:
-	case DRM_FORMAT_YVU410:
-		return 4;
-	case DRM_FORMAT_YUV420:
-	case DRM_FORMAT_YVU420:
-	case DRM_FORMAT_NV12:
-	case DRM_FORMAT_NV21:
-		return 2;
-	default:
-		return 1;
-	}
-}
-EXPORT_SYMBOL(drm_format_vert_chroma_subsampling);
-
-/**
- * drm_format_plane_width - width of the plane given the first plane
- * @width: width of the first plane
- * @format: pixel format
- * @plane: plane index
- *
- * Returns:
- * The width of @plane, given that the width of the first plane is @width.
- */
-int drm_format_plane_width(int width, uint32_t format, int plane)
-{
-	if (plane >= drm_format_num_planes(format))
-		return 0;
-
-	if (plane == 0)
-		return width;
-
-	return width / drm_format_horz_chroma_subsampling(format);
-}
-EXPORT_SYMBOL(drm_format_plane_width);
-
-/**
- * drm_format_plane_height - height of the plane given the first plane
- * @height: height of the first plane
- * @format: pixel format
- * @plane: plane index
- *
- * Returns:
- * The height of @plane, given that the height of the first plane is @height.
- */
-int drm_format_plane_height(int height, uint32_t format, int plane)
-{
-	if (plane >= drm_format_num_planes(format))
-		return 0;
-
-	if (plane == 0)
-		return height;
-
-	return height / drm_format_vert_chroma_subsampling(format);
-}
-EXPORT_SYMBOL(drm_format_plane_height);
-
-/**
  * drm_rotation_simplify() - Try to simplify the rotation
  * @rotation: Rotation to be simplified
  * @supported_rotations: Supported rotations
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
new file mode 100644
index 000000000000..0645c85d5f95
--- /dev/null
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -0,0 +1,320 @@
+/*
+ * Copyright (c) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * DRM core format related functions
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#include <linux/bug.h>
+#include <linux/ctype.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_fourcc.h>
+
+static char printable_char(int c)
+{
+	return isascii(c) && isprint(c) ? c : '?';
+}
+
+/**
+ * drm_get_format_name - return a string for drm fourcc format
+ * @format: format to compute name of
+ *
+ * Note that the buffer used by this function is globally shared and owned by
+ * the function itself.
+ *
+ * FIXME: This isn't really multithreading safe.
+ */
+const char *drm_get_format_name(uint32_t format)
+{
+	static char buf[32];
+
+	snprintf(buf, sizeof(buf),
+		 "%c%c%c%c %s-endian (0x%08x)",
+		 printable_char(format & 0xff),
+		 printable_char((format >> 8) & 0xff),
+		 printable_char((format >> 16) & 0xff),
+		 printable_char((format >> 24) & 0x7f),
+		 format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
+		 format);
+
+	return buf;
+}
+EXPORT_SYMBOL(drm_get_format_name);
+
+/**
+ * drm_fb_get_bpp_depth - get the bpp/depth values for format
+ * @format: pixel format (DRM_FORMAT_*)
+ * @depth: storage for the depth value
+ * @bpp: storage for the bpp value
+ *
+ * This only supports RGB formats here for compat with code that doesn't use
+ * pixel formats directly yet.
+ */
+void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
+			  int *bpp)
+{
+	switch (format) {
+	case DRM_FORMAT_C8:
+	case DRM_FORMAT_RGB332:
+	case DRM_FORMAT_BGR233:
+		*depth = 8;
+		*bpp = 8;
+		break;
+	case DRM_FORMAT_XRGB1555:
+	case DRM_FORMAT_XBGR1555:
+	case DRM_FORMAT_RGBX5551:
+	case DRM_FORMAT_BGRX5551:
+	case DRM_FORMAT_ARGB1555:
+	case DRM_FORMAT_ABGR1555:
+	case DRM_FORMAT_RGBA5551:
+	case DRM_FORMAT_BGRA5551:
+		*depth = 15;
+		*bpp = 16;
+		break;
+	case DRM_FORMAT_RGB565:
+	case DRM_FORMAT_BGR565:
+		*depth = 16;
+		*bpp = 16;
+		break;
+	case DRM_FORMAT_RGB888:
+	case DRM_FORMAT_BGR888:
+		*depth = 24;
+		*bpp = 24;
+		break;
+	case DRM_FORMAT_XRGB8888:
+	case DRM_FORMAT_XBGR8888:
+	case DRM_FORMAT_RGBX8888:
+	case DRM_FORMAT_BGRX8888:
+		*depth = 24;
+		*bpp = 32;
+		break;
+	case DRM_FORMAT_XRGB2101010:
+	case DRM_FORMAT_XBGR2101010:
+	case DRM_FORMAT_RGBX1010102:
+	case DRM_FORMAT_BGRX1010102:
+	case DRM_FORMAT_ARGB2101010:
+	case DRM_FORMAT_ABGR2101010:
+	case DRM_FORMAT_RGBA1010102:
+	case DRM_FORMAT_BGRA1010102:
+		*depth = 30;
+		*bpp = 32;
+		break;
+	case DRM_FORMAT_ARGB8888:
+	case DRM_FORMAT_ABGR8888:
+	case DRM_FORMAT_RGBA8888:
+	case DRM_FORMAT_BGRA8888:
+		*depth = 32;
+		*bpp = 32;
+		break;
+	default:
+		DRM_DEBUG_KMS("unsupported pixel format %s\n",
+			      drm_get_format_name(format));
+		*depth = 0;
+		*bpp = 0;
+		break;
+	}
+}
+EXPORT_SYMBOL(drm_fb_get_bpp_depth);
+
+/**
+ * drm_format_num_planes - get the number of planes for format
+ * @format: pixel format (DRM_FORMAT_*)
+ *
+ * Returns:
+ * The number of planes used by the specified pixel format.
+ */
+int drm_format_num_planes(uint32_t format)
+{
+	switch (format) {
+	case DRM_FORMAT_YUV410:
+	case DRM_FORMAT_YVU410:
+	case DRM_FORMAT_YUV411:
+	case DRM_FORMAT_YVU411:
+	case DRM_FORMAT_YUV420:
+	case DRM_FORMAT_YVU420:
+	case DRM_FORMAT_YUV422:
+	case DRM_FORMAT_YVU422:
+	case DRM_FORMAT_YUV444:
+	case DRM_FORMAT_YVU444:
+		return 3;
+	case DRM_FORMAT_NV12:
+	case DRM_FORMAT_NV21:
+	case DRM_FORMAT_NV16:
+	case DRM_FORMAT_NV61:
+	case DRM_FORMAT_NV24:
+	case DRM_FORMAT_NV42:
+		return 2;
+	default:
+		return 1;
+	}
+}
+EXPORT_SYMBOL(drm_format_num_planes);
+
+/**
+ * drm_format_plane_cpp - determine the bytes per pixel value
+ * @format: pixel format (DRM_FORMAT_*)
+ * @plane: plane index
+ *
+ * Returns:
+ * The bytes per pixel value for the specified plane.
+ */
+int drm_format_plane_cpp(uint32_t format, int plane)
+{
+	unsigned int depth;
+	int bpp;
+
+	if (plane >= drm_format_num_planes(format))
+		return 0;
+
+	switch (format) {
+	case DRM_FORMAT_YUYV:
+	case DRM_FORMAT_YVYU:
+	case DRM_FORMAT_UYVY:
+	case DRM_FORMAT_VYUY:
+		return 2;
+	case DRM_FORMAT_NV12:
+	case DRM_FORMAT_NV21:
+	case DRM_FORMAT_NV16:
+	case DRM_FORMAT_NV61:
+	case DRM_FORMAT_NV24:
+	case DRM_FORMAT_NV42:
+		return plane ? 2 : 1;
+	case DRM_FORMAT_YUV410:
+	case DRM_FORMAT_YVU410:
+	case DRM_FORMAT_YUV411:
+	case DRM_FORMAT_YVU411:
+	case DRM_FORMAT_YUV420:
+	case DRM_FORMAT_YVU420:
+	case DRM_FORMAT_YUV422:
+	case DRM_FORMAT_YVU422:
+	case DRM_FORMAT_YUV444:
+	case DRM_FORMAT_YVU444:
+		return 1;
+	default:
+		drm_fb_get_bpp_depth(format, &depth, &bpp);
+		return bpp >> 3;
+	}
+}
+EXPORT_SYMBOL(drm_format_plane_cpp);
+
+/**
+ * drm_format_horz_chroma_subsampling - get the horizontal chroma subsampling factor
+ * @format: pixel format (DRM_FORMAT_*)
+ *
+ * Returns:
+ * The horizontal chroma subsampling factor for the
+ * specified pixel format.
+ */
+int drm_format_horz_chroma_subsampling(uint32_t format)
+{
+	switch (format) {
+	case DRM_FORMAT_YUV411:
+	case DRM_FORMAT_YVU411:
+	case DRM_FORMAT_YUV410:
+	case DRM_FORMAT_YVU410:
+		return 4;
+	case DRM_FORMAT_YUYV:
+	case DRM_FORMAT_YVYU:
+	case DRM_FORMAT_UYVY:
+	case DRM_FORMAT_VYUY:
+	case DRM_FORMAT_NV12:
+	case DRM_FORMAT_NV21:
+	case DRM_FORMAT_NV16:
+	case DRM_FORMAT_NV61:
+	case DRM_FORMAT_YUV422:
+	case DRM_FORMAT_YVU422:
+	case DRM_FORMAT_YUV420:
+	case DRM_FORMAT_YVU420:
+		return 2;
+	default:
+		return 1;
+	}
+}
+EXPORT_SYMBOL(drm_format_horz_chroma_subsampling);
+
+/**
+ * drm_format_vert_chroma_subsampling - get the vertical chroma subsampling factor
+ * @format: pixel format (DRM_FORMAT_*)
+ *
+ * Returns:
+ * The vertical chroma subsampling factor for the
+ * specified pixel format.
+ */
+int drm_format_vert_chroma_subsampling(uint32_t format)
+{
+	switch (format) {
+	case DRM_FORMAT_YUV410:
+	case DRM_FORMAT_YVU410:
+		return 4;
+	case DRM_FORMAT_YUV420:
+	case DRM_FORMAT_YVU420:
+	case DRM_FORMAT_NV12:
+	case DRM_FORMAT_NV21:
+		return 2;
+	default:
+		return 1;
+	}
+}
+EXPORT_SYMBOL(drm_format_vert_chroma_subsampling);
+
+/**
+ * drm_format_plane_width - width of the plane given the first plane
+ * @width: width of the first plane
+ * @format: pixel format
+ * @plane: plane index
+ *
+ * Returns:
+ * The width of @plane, given that the width of the first plane is @width.
+ */
+int drm_format_plane_width(int width, uint32_t format, int plane)
+{
+	if (plane >= drm_format_num_planes(format))
+		return 0;
+
+	if (plane == 0)
+		return width;
+
+	return width / drm_format_horz_chroma_subsampling(format);
+}
+EXPORT_SYMBOL(drm_format_plane_width);
+
+/**
+ * drm_format_plane_height - height of the plane given the first plane
+ * @height: height of the first plane
+ * @format: pixel format
+ * @plane: plane index
+ *
+ * Returns:
+ * The height of @plane, given that the height of the first plane is @height.
+ */
+int drm_format_plane_height(int height, uint32_t format, int plane)
+{
+	if (plane >= drm_format_num_planes(format))
+		return 0;
+
+	if (plane == 0)
+		return height;
+
+	return height / drm_format_vert_chroma_subsampling(format);
+}
+EXPORT_SYMBOL(drm_format_plane_height);
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 84f1a8eefbdb..c8879057084e 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -66,6 +66,7 @@
 
 #include <drm/drm_agpsupport.h>
 #include <drm/drm_crtc.h>
+#include <drm/drm_fourcc.h>
 #include <drm/drm_global.h>
 #include <drm/drm_hashtab.h>
 #include <drm/drm_mem_util.h>
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index d1559cd04e3d..1b80c0268d8f 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -2540,15 +2540,6 @@ extern int drm_mode_plane_set_obj_prop(struct drm_plane *plane,
 extern int drm_mode_atomic_ioctl(struct drm_device *dev,
 				 void *data, struct drm_file *file_priv);
 
-extern void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
-				 int *bpp);
-extern int drm_format_num_planes(uint32_t format);
-extern int drm_format_plane_cpp(uint32_t format, int plane);
-extern int drm_format_horz_chroma_subsampling(uint32_t format);
-extern int drm_format_vert_chroma_subsampling(uint32_t format);
-extern int drm_format_plane_width(int width, uint32_t format, int plane);
-extern int drm_format_plane_height(int height, uint32_t format, int plane);
-extern const char *drm_get_format_name(uint32_t format);
 extern struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
 							      unsigned int supported_rotations);
 extern unsigned int drm_rotation_simplify(unsigned int rotation,
diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
new file mode 100644
index 000000000000..7f90a396cf2b
--- /dev/null
+++ b/include/drm/drm_fourcc.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+#ifndef __DRM_FOURCC_H__
+#define __DRM_FOURCC_H__
+
+#include <linux/types.h>
+#include <uapi/drm/drm_fourcc.h>
+
+void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth, int *bpp);
+int drm_format_num_planes(uint32_t format);
+int drm_format_plane_cpp(uint32_t format, int plane);
+int drm_format_horz_chroma_subsampling(uint32_t format);
+int drm_format_vert_chroma_subsampling(uint32_t format);
+int drm_format_plane_width(int width, uint32_t format, int plane);
+int drm_format_plane_height(int height, uint32_t format, int plane);
+const char *drm_get_format_name(uint32_t format);
+
+#endif /* __DRM_FOURCC_H__ */
-- 
Regards,

Laurent Pinchart

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH v2 2/5] drm: Centralize format information

[Laurent Pinchart]

Various pieces of information about DRM formats (number of planes, color
depth, chroma subsampling, ...) are scattered across different helper
functions in the DRM core. Callers of those functions often need to
access more than a single parameter of the format, leading to
inefficiencies due to multiple lookups.

Centralize all format information in a data structure and create a
function to look up information based on the format 4CC.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/gpu/drm/drm_fourcc.c | 84 ++++++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_fourcc.h     | 21 +++++++++++
 2 files changed, 105 insertions(+)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 0645c85d5f95..463254dc7f1e 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -62,6 +62,90 @@ const char *drm_get_format_name(uint32_t format)
 EXPORT_SYMBOL(drm_get_format_name);
 
 /**
+ * drm_format_info - query information for a given format
+ * @format: pixel format (DRM_FORMAT_*)
+ *
+ * Returns:
+ * The instance of struct drm_format_info that describes the pixel format, or
+ * NULL if the format is unsupported.
+ */
+const struct drm_format_info *drm_format_info(u32 format)
+{
+	static const struct drm_format_info formats[] = { 
+		{ .format = DRM_FORMAT_C8,		.depth = 8,  .bpp = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGB332,		.depth = 8,  .bpp = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGR233,		.depth = 8,  .bpp = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_XRGB4444,	.depth = 12, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_XBGR4444,	.depth = 12, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGBX4444,	.depth = 12, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGRX4444,	.depth = 12, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_ARGB4444,	.depth = 12, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_ABGR4444,	.depth = 12, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGBA4444,	.depth = 12, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGRA4444,	.depth = 12, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_XRGB1555,	.depth = 15, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_XBGR1555,	.depth = 15, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGBX5551,	.depth = 15, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGRX5551,	.depth = 15, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_ARGB1555,	.depth = 15, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_ABGR1555,	.depth = 15, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGBA5551,	.depth = 15, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGRA5551,	.depth = 15, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGB565,		.depth = 16, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGR565,		.depth = 16, .bpp = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGB888,		.depth = 24, .bpp = 24, .num_planes = 1, .cpp = { 3, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGR888,		.depth = 24, .bpp = 24, .num_planes = 1, .cpp = { 3, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_XRGB8888,	.depth = 24, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_XBGR8888,	.depth = 24, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGBX8888,	.depth = 24, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGRX8888,	.depth = 24, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_XRGB2101010,	.depth = 30, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_XBGR2101010,	.depth = 30, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGBX1010102,	.depth = 30, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGRX1010102,	.depth = 30, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_ARGB2101010,	.depth = 30, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_ABGR2101010,	.depth = 30, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGBA1010102,	.depth = 30, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGRA1010102,	.depth = 30, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_ARGB8888,	.depth = 32, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_ABGR8888,	.depth = 32, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_RGBA8888,	.depth = 32, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_BGRA8888,	.depth = 32, .bpp = 32, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_YUV410,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 4, .vsub = 4 },
+		{ .format = DRM_FORMAT_YVU410,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 4, .vsub = 4 },
+		{ .format = DRM_FORMAT_YUV411,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 4, .vsub = 1 },
+		{ .format = DRM_FORMAT_YVU411,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 4, .vsub = 1 },
+		{ .format = DRM_FORMAT_YUV420,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 2 },
+		{ .format = DRM_FORMAT_YVU420,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 2 },
+		{ .format = DRM_FORMAT_YUV422,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1 },
+		{ .format = DRM_FORMAT_YVU422,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1 },
+		{ .format = DRM_FORMAT_YUV444,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_YVU444,		.depth = 0,  .bpp = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_NV12,		.depth = 0,  .bpp = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2 },
+		{ .format = DRM_FORMAT_NV21,		.depth = 0,  .bpp = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2 },
+		{ .format = DRM_FORMAT_NV16,		.depth = 0,  .bpp = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1 },
+		{ .format = DRM_FORMAT_NV61,		.depth = 0,  .bpp = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1 },
+		{ .format = DRM_FORMAT_NV24,		.depth = 0,  .bpp = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_NV42,		.depth = 0,  .bpp = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 1, .vsub = 1 },
+		{ .format = DRM_FORMAT_YUYV,		.depth = 0,  .bpp = 0,  .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 2, .vsub = 1 },
+		{ .format = DRM_FORMAT_YVYU,		.depth = 0,  .bpp = 0,  .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 2, .vsub = 1 },
+		{ .format = DRM_FORMAT_UYVY,		.depth = 0,  .bpp = 0,  .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 2, .vsub = 1 },
+		{ .format = DRM_FORMAT_VYUY,		.depth = 0,  .bpp = 0,  .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 2, .vsub = 1 },
+		{ .format = DRM_FORMAT_AYUV,		.depth = 0,  .bpp = 0,  .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
+	};
+
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(formats); ++i) {
+		if (formats[i].format == format)
+			return &formats[i];
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(drm_format_info);
+
+/**
  * drm_fb_get_bpp_depth - get the bpp/depth values for format
  * @format: pixel format (DRM_FORMAT_*)
  * @depth: storage for the depth value
diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
index 7f90a396cf2b..d33411bd19b1 100644
--- a/include/drm/drm_fourcc.h
+++ b/include/drm/drm_fourcc.h
@@ -25,6 +25,27 @@
 #include <linux/types.h>
 #include <uapi/drm/drm_fourcc.h>
 
+/**
+ * struct drm_format_info - information about a DRM format
+ * @format: 4CC format identifier (DRM_FORMAT_*)
+ * @depth: color depth (number of bits per pixel excluding padding bits)
+ * @bpp: number of bits per pixel including padding
+ * @num_planes: number of color planes (1 to 3)
+ * @cpp: number of bytes per pixel (per plane)
+ * @hsub: horizontal chroma subsampling factor
+ * @vsub: vertical chroma subsampling factor
+ */
+struct drm_format_info {
+	u32 format;
+	u8 depth;
+	u8 bpp;
+	u8 num_planes;
+	u8 cpp[3];
+	u8 hsub;
+	u8 vsub;
+};
+
+const struct drm_format_info *drm_format_info(u32 format);
 void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth, int *bpp);
 int drm_format_num_planes(uint32_t format);
 int drm_format_plane_cpp(uint32_t format, int plane);
-- 
Regards,

Laurent Pinchart

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH v2 3/5] drm: Implement the drm_format_*() helpers as drm_format_info() wrappers

[Laurent Pinchart]

Turn the drm_format_*() helpers into wrappers around the drm_format_info
lookup function to centralize all format information in a single place.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/gpu/drm/drm_fourcc.c | 180 ++++++++-----------------------------------
 1 file changed, 34 insertions(+), 146 deletions(-)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 463254dc7f1e..0c2cdab7f974 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -157,66 +157,19 @@ EXPORT_SYMBOL(drm_format_info);
 void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
 			  int *bpp)
 {
-	switch (format) {
-	case DRM_FORMAT_C8:
-	case DRM_FORMAT_RGB332:
-	case DRM_FORMAT_BGR233:
-		*depth = 8;
-		*bpp = 8;
-		break;
-	case DRM_FORMAT_XRGB1555:
-	case DRM_FORMAT_XBGR1555:
-	case DRM_FORMAT_RGBX5551:
-	case DRM_FORMAT_BGRX5551:
-	case DRM_FORMAT_ARGB1555:
-	case DRM_FORMAT_ABGR1555:
-	case DRM_FORMAT_RGBA5551:
-	case DRM_FORMAT_BGRA5551:
-		*depth = 15;
-		*bpp = 16;
-		break;
-	case DRM_FORMAT_RGB565:
-	case DRM_FORMAT_BGR565:
-		*depth = 16;
-		*bpp = 16;
-		break;
-	case DRM_FORMAT_RGB888:
-	case DRM_FORMAT_BGR888:
-		*depth = 24;
-		*bpp = 24;
-		break;
-	case DRM_FORMAT_XRGB8888:
-	case DRM_FORMAT_XBGR8888:
-	case DRM_FORMAT_RGBX8888:
-	case DRM_FORMAT_BGRX8888:
-		*depth = 24;
-		*bpp = 32;
-		break;
-	case DRM_FORMAT_XRGB2101010:
-	case DRM_FORMAT_XBGR2101010:
-	case DRM_FORMAT_RGBX1010102:
-	case DRM_FORMAT_BGRX1010102:
-	case DRM_FORMAT_ARGB2101010:
-	case DRM_FORMAT_ABGR2101010:
-	case DRM_FORMAT_RGBA1010102:
-	case DRM_FORMAT_BGRA1010102:
-		*depth = 30;
-		*bpp = 32;
-		break;
-	case DRM_FORMAT_ARGB8888:
-	case DRM_FORMAT_ABGR8888:
-	case DRM_FORMAT_RGBA8888:
-	case DRM_FORMAT_BGRA8888:
-		*depth = 32;
-		*bpp = 32;
-		break;
-	default:
+	const struct drm_format_info *info;
+
+	info = drm_format_info(format);
+	if (!info || !info->depth || !info->bpp) {
 		DRM_DEBUG_KMS("unsupported pixel format %s\n",
 			      drm_get_format_name(format));
 		*depth = 0;
 		*bpp = 0;
-		break;
+		return;
 	}
+
+	*depth = info->depth;
+	*bpp = info->bpp;
 }
 EXPORT_SYMBOL(drm_fb_get_bpp_depth);
 
@@ -229,28 +182,10 @@ EXPORT_SYMBOL(drm_fb_get_bpp_depth);
  */
 int drm_format_num_planes(uint32_t format)
 {
-	switch (format) {
-	case DRM_FORMAT_YUV410:
-	case DRM_FORMAT_YVU410:
-	case DRM_FORMAT_YUV411:
-	case DRM_FORMAT_YVU411:
-	case DRM_FORMAT_YUV420:
-	case DRM_FORMAT_YVU420:
-	case DRM_FORMAT_YUV422:
-	case DRM_FORMAT_YVU422:
-	case DRM_FORMAT_YUV444:
-	case DRM_FORMAT_YVU444:
-		return 3;
-	case DRM_FORMAT_NV12:
-	case DRM_FORMAT_NV21:
-	case DRM_FORMAT_NV16:
-	case DRM_FORMAT_NV61:
-	case DRM_FORMAT_NV24:
-	case DRM_FORMAT_NV42:
-		return 2;
-	default:
-		return 1;
-	}
+	const struct drm_format_info *info;
+
+	info = drm_format_info(format);
+	return info ? info->num_planes : 1;
 }
 EXPORT_SYMBOL(drm_format_num_planes);
 
@@ -264,40 +199,13 @@ EXPORT_SYMBOL(drm_format_num_planes);
  */
 int drm_format_plane_cpp(uint32_t format, int plane)
 {
-	unsigned int depth;
-	int bpp;
+	const struct drm_format_info *info;
 
-	if (plane >= drm_format_num_planes(format))
+	info = drm_format_info(format);
+	if (!info || plane >= info->num_planes)
 		return 0;
 
-	switch (format) {
-	case DRM_FORMAT_YUYV:
-	case DRM_FORMAT_YVYU:
-	case DRM_FORMAT_UYVY:
-	case DRM_FORMAT_VYUY:
-		return 2;
-	case DRM_FORMAT_NV12:
-	case DRM_FORMAT_NV21:
-	case DRM_FORMAT_NV16:
-	case DRM_FORMAT_NV61:
-	case DRM_FORMAT_NV24:
-	case DRM_FORMAT_NV42:
-		return plane ? 2 : 1;
-	case DRM_FORMAT_YUV410:
-	case DRM_FORMAT_YVU410:
-	case DRM_FORMAT_YUV411:
-	case DRM_FORMAT_YVU411:
-	case DRM_FORMAT_YUV420:
-	case DRM_FORMAT_YVU420:
-	case DRM_FORMAT_YUV422:
-	case DRM_FORMAT_YVU422:
-	case DRM_FORMAT_YUV444:
-	case DRM_FORMAT_YVU444:
-		return 1;
-	default:
-		drm_fb_get_bpp_depth(format, &depth, &bpp);
-		return bpp >> 3;
-	}
+	return info->cpp[plane];
 }
 EXPORT_SYMBOL(drm_format_plane_cpp);
 
@@ -311,28 +219,10 @@ EXPORT_SYMBOL(drm_format_plane_cpp);
  */
 int drm_format_horz_chroma_subsampling(uint32_t format)
 {
-	switch (format) {
-	case DRM_FORMAT_YUV411:
-	case DRM_FORMAT_YVU411:
-	case DRM_FORMAT_YUV410:
-	case DRM_FORMAT_YVU410:
-		return 4;
-	case DRM_FORMAT_YUYV:
-	case DRM_FORMAT_YVYU:
-	case DRM_FORMAT_UYVY:
-	case DRM_FORMAT_VYUY:
-	case DRM_FORMAT_NV12:
-	case DRM_FORMAT_NV21:
-	case DRM_FORMAT_NV16:
-	case DRM_FORMAT_NV61:
-	case DRM_FORMAT_YUV422:
-	case DRM_FORMAT_YVU422:
-	case DRM_FORMAT_YUV420:
-	case DRM_FORMAT_YVU420:
-		return 2;
-	default:
-		return 1;
-	}
+	const struct drm_format_info *info;
+
+	info = drm_format_info(format);
+	return info ? info->hsub : 1;
 }
 EXPORT_SYMBOL(drm_format_horz_chroma_subsampling);
 
@@ -346,18 +236,10 @@ EXPORT_SYMBOL(drm_format_horz_chroma_subsampling);
  */
 int drm_format_vert_chroma_subsampling(uint32_t format)
 {
-	switch (format) {
-	case DRM_FORMAT_YUV410:
-	case DRM_FORMAT_YVU410:
-		return 4;
-	case DRM_FORMAT_YUV420:
-	case DRM_FORMAT_YVU420:
-	case DRM_FORMAT_NV12:
-	case DRM_FORMAT_NV21:
-		return 2;
-	default:
-		return 1;
-	}
+	const struct drm_format_info *info;
+
+	info = drm_format_info(format);
+	return info ? info->vsub : 1;
 }
 EXPORT_SYMBOL(drm_format_vert_chroma_subsampling);
 
@@ -372,13 +254,16 @@ EXPORT_SYMBOL(drm_format_vert_chroma_subsampling);
  */
 int drm_format_plane_width(int width, uint32_t format, int plane)
 {
-	if (plane >= drm_format_num_planes(format))
+	const struct drm_format_info *info;
+
+	info = drm_format_info(format);
+	if (!info || plane >= info->num_planes)
 		return 0;
 
 	if (plane == 0)
 		return width;
 
-	return width / drm_format_horz_chroma_subsampling(format);
+	return width / info->hsub;
 }
 EXPORT_SYMBOL(drm_format_plane_width);
 
@@ -393,12 +278,15 @@ EXPORT_SYMBOL(drm_format_plane_width);
  */
 int drm_format_plane_height(int height, uint32_t format, int plane)
 {
-	if (plane >= drm_format_num_planes(format))
+	const struct drm_format_info *info;
+
+	info = drm_format_info(format);
+	if (!info || plane >= info->num_planes)
 		return 0;
 
 	if (plane == 0)
 		return height;
 
-	return height / drm_format_vert_chroma_subsampling(format);
+	return height / info->vsub;
 }
 EXPORT_SYMBOL(drm_format_plane_height);
-- 
Regards,

Laurent Pinchart

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[PATCH v2 4/5] drm: Use drm_format_info() in DRM core code

[Laurent Pinchart]

Replace calls to the drm_format_*() helper functions with direct use of
the drm_format_info structure. This improves efficiency by removing
duplicate lookups.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/gpu/drm/drm_crtc.c          | 100 +++++-------------------------------
 drivers/gpu/drm/drm_fb_cma_helper.c |  23 +++++----
 2 files changed, 25 insertions(+), 98 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index e5369529af06..73fa7f2a1a04 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -3173,108 +3173,32 @@ int drm_mode_addfb(struct drm_device *dev,
 	return 0;
 }
 
-static int format_check(const struct drm_mode_fb_cmd2 *r)
-{
-	uint32_t format = r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN;
-
-	switch (format) {
-	case DRM_FORMAT_C8:
-	case DRM_FORMAT_RGB332:
-	case DRM_FORMAT_BGR233:
-	case DRM_FORMAT_XRGB4444:
-	case DRM_FORMAT_XBGR4444:
-	case DRM_FORMAT_RGBX4444:
-	case DRM_FORMAT_BGRX4444:
-	case DRM_FORMAT_ARGB4444:
-	case DRM_FORMAT_ABGR4444:
-	case DRM_FORMAT_RGBA4444:
-	case DRM_FORMAT_BGRA4444:
-	case DRM_FORMAT_XRGB1555:
-	case DRM_FORMAT_XBGR1555:
-	case DRM_FORMAT_RGBX5551:
-	case DRM_FORMAT_BGRX5551:
-	case DRM_FORMAT_ARGB1555:
-	case DRM_FORMAT_ABGR1555:
-	case DRM_FORMAT_RGBA5551:
-	case DRM_FORMAT_BGRA5551:
-	case DRM_FORMAT_RGB565:
-	case DRM_FORMAT_BGR565:
-	case DRM_FORMAT_RGB888:
-	case DRM_FORMAT_BGR888:
-	case DRM_FORMAT_XRGB8888:
-	case DRM_FORMAT_XBGR8888:
-	case DRM_FORMAT_RGBX8888:
-	case DRM_FORMAT_BGRX8888:
-	case DRM_FORMAT_ARGB8888:
-	case DRM_FORMAT_ABGR8888:
-	case DRM_FORMAT_RGBA8888:
-	case DRM_FORMAT_BGRA8888:
-	case DRM_FORMAT_XRGB2101010:
-	case DRM_FORMAT_XBGR2101010:
-	case DRM_FORMAT_RGBX1010102:
-	case DRM_FORMAT_BGRX1010102:
-	case DRM_FORMAT_ARGB2101010:
-	case DRM_FORMAT_ABGR2101010:
-	case DRM_FORMAT_RGBA1010102:
-	case DRM_FORMAT_BGRA1010102:
-	case DRM_FORMAT_YUYV:
-	case DRM_FORMAT_YVYU:
-	case DRM_FORMAT_UYVY:
-	case DRM_FORMAT_VYUY:
-	case DRM_FORMAT_AYUV:
-	case DRM_FORMAT_NV12:
-	case DRM_FORMAT_NV21:
-	case DRM_FORMAT_NV16:
-	case DRM_FORMAT_NV61:
-	case DRM_FORMAT_NV24:
-	case DRM_FORMAT_NV42:
-	case DRM_FORMAT_YUV410:
-	case DRM_FORMAT_YVU410:
-	case DRM_FORMAT_YUV411:
-	case DRM_FORMAT_YVU411:
-	case DRM_FORMAT_YUV420:
-	case DRM_FORMAT_YVU420:
-	case DRM_FORMAT_YUV422:
-	case DRM_FORMAT_YVU422:
-	case DRM_FORMAT_YUV444:
-	case DRM_FORMAT_YVU444:
-		return 0;
-	default:
-		DRM_DEBUG_KMS("invalid pixel format %s\n",
-			      drm_get_format_name(r->pixel_format));
-		return -EINVAL;
-	}
-}
-
 static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
 {
-	int ret, hsub, vsub, num_planes, i;
+	const struct drm_format_info *info;
+	int i;
 
-	ret = format_check(r);
-	if (ret) {
+	info = drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
+	if (!info) {
 		DRM_DEBUG_KMS("bad framebuffer format %s\n",
 			      drm_get_format_name(r->pixel_format));
-		return ret;
+		return -EINVAL;
 	}
 
-	hsub = drm_format_horz_chroma_subsampling(r->pixel_format);
-	vsub = drm_format_vert_chroma_subsampling(r->pixel_format);
-	num_planes = drm_format_num_planes(r->pixel_format);
-
-	if (r->width == 0 || r->width % hsub) {
+	if (r->width == 0 || r->width % info->hsub) {
 		DRM_DEBUG_KMS("bad framebuffer width %u\n", r->width);
 		return -EINVAL;
 	}
 
-	if (r->height == 0 || r->height % vsub) {
+	if (r->height == 0 || r->height % info->vsub) {
 		DRM_DEBUG_KMS("bad framebuffer height %u\n", r->height);
 		return -EINVAL;
 	}
 
-	for (i = 0; i < num_planes; i++) {
-		unsigned int width = r->width / (i != 0 ? hsub : 1);
-		unsigned int height = r->height / (i != 0 ? vsub : 1);
-		unsigned int cpp = drm_format_plane_cpp(r->pixel_format, i);
+	for (i = 0; i < info->num_planes; i++) {
+		unsigned int width = r->width / (i != 0 ? info->hsub : 1);
+		unsigned int height = r->height / (i != 0 ? info->vsub : 1);
+		unsigned int cpp = info->cpp[i];
 
 		if (!r->handles[i]) {
 			DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
@@ -3317,7 +3241,7 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
 		}
 	}
 
-	for (i = num_planes; i < 4; i++) {
+	for (i = info->num_planes; i < 4; i++) {
 		if (r->modifier[i]) {
 			DRM_DEBUG_KMS("non-zero modifier for unused plane %d\n", i);
 			return -EINVAL;
diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
index 5075fae3c4e2..81525a23e4b7 100644
--- a/drivers/gpu/drm/drm_fb_cma_helper.c
+++ b/drivers/gpu/drm/drm_fb_cma_helper.c
@@ -171,20 +171,20 @@ struct drm_framebuffer *drm_fb_cma_create_with_funcs(struct drm_device *dev,
 	struct drm_file *file_priv, const struct drm_mode_fb_cmd2 *mode_cmd,
 	const struct drm_framebuffer_funcs *funcs)
 {
+	const struct drm_format_info *info;
 	struct drm_fb_cma *fb_cma;
 	struct drm_gem_cma_object *objs[4];
 	struct drm_gem_object *obj;
-	unsigned int hsub;
-	unsigned int vsub;
 	int ret;
 	int i;
 
-	hsub = drm_format_horz_chroma_subsampling(mode_cmd->pixel_format);
-	vsub = drm_format_vert_chroma_subsampling(mode_cmd->pixel_format);
+	info = drm_format_info(mode_cmd->pixel_format);
+	if (!info)
+		return -EINVAL;
 
-	for (i = 0; i < drm_format_num_planes(mode_cmd->pixel_format); i++) {
-		unsigned int width = mode_cmd->width / (i ? hsub : 1);
-		unsigned int height = mode_cmd->height / (i ? vsub : 1);
+	for (i = 0; i < info->num_planes; i++) {
+		unsigned int width = mode_cmd->width / (i ? info->hsub : 1);
+		unsigned int height = mode_cmd->height / (i ? info->vsub : 1);
 		unsigned int min_size;
 
 		obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[i]);
@@ -195,7 +195,7 @@ struct drm_framebuffer *drm_fb_cma_create_with_funcs(struct drm_device *dev,
 		}
 
 		min_size = (height - 1) * mode_cmd->pitches[i]
-			 + width * drm_format_plane_cpp(mode_cmd->pixel_format, i)
+			 + width * info->cpp[i]
 			 + mode_cmd->offsets[i];
 
 		if (obj->size < min_size) {
@@ -265,12 +265,15 @@ EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);
 static void drm_fb_cma_describe(struct drm_framebuffer *fb, struct seq_file *m)
 {
 	struct drm_fb_cma *fb_cma = to_fb_cma(fb);
-	int i, n = drm_format_num_planes(fb->pixel_format);
+	const struct drm_format_info *info;
+	int i;
 
 	seq_printf(m, "fb: %dx%d@%4.4s\n", fb->width, fb->height,
 			(char *)&fb->pixel_format);
 
-	for (i = 0; i < n; i++) {
+	info = drm_format_info(fb->pixel_format);
+
+	for (i = 0; i < info->num_planes; i++) {
 		seq_printf(m, "   %d: offset=%d pitch=%d, obj: ",
 				i, fb->offsets[i], fb->pitches[i]);
 		drm_gem_cma_describe(fb_cma->obj[i], m);
-- 
Regards,

Laurent Pinchart

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[PATCH v2 5/5] drm: WARN when calling drm_format_info() for an unsupported format

[Laurent Pinchart]

The format helpers have historically treated unsupported formats as part
of the default case, returning values that are likely wrong. We can't
change this behaviour now without risking breaking drivers in difficult
to detect ways, but we can WARN on unsupported formats to catch faulty
callers.

The only exception is the framebuffer_check() function that calls
drm_format_info() to validate the format passed from userspace. This is
a valid use case that shouldn't generate a warning.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/gpu/drm/drm_crtc.c   |  2 +-
 drivers/gpu/drm/drm_fourcc.c | 32 ++++++++++++++++++++++++--------
 include/drm/drm_fourcc.h     |  1 +
 3 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 73fa7f2a1a04..1777ab37890a 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -3178,7 +3178,7 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
 	const struct drm_format_info *info;
 	int i;
 
-	info = drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
+	info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
 	if (!info) {
 		DRM_DEBUG_KMS("bad framebuffer format %s\n",
 			      drm_get_format_name(r->pixel_format));
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 0c2cdab7f974..1dfbcaa6cd03 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -61,15 +61,11 @@ const char *drm_get_format_name(uint32_t format)
 }
 EXPORT_SYMBOL(drm_get_format_name);
 
-/**
- * drm_format_info - query information for a given format
- * @format: pixel format (DRM_FORMAT_*)
- *
- * Returns:
- * The instance of struct drm_format_info that describes the pixel format, or
- * NULL if the format is unsupported.
+/*
+ * Internal function to query information for a given format. See
+ * drm_format_info() for the public API.
  */
-const struct drm_format_info *drm_format_info(u32 format)
+const struct drm_format_info *__drm_format_info(u32 format)
 {
 	static const struct drm_format_info formats[] = { 
 		{ .format = DRM_FORMAT_C8,		.depth = 8,  .bpp = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
@@ -143,6 +139,26 @@ const struct drm_format_info *drm_format_info(u32 format)
 
 	return NULL;
 }
+
+/**
+ * drm_format_info - query information for a given format
+ * @format: pixel format (DRM_FORMAT_*)
+ *
+ * The caller should only pass a supported pixel format to this function.
+ * Unsupported pixel formats will generate a warning in the kernel log.
+ *
+ * Returns:
+ * The instance of struct drm_format_info that describes the pixel format, or
+ * NULL if the format is unsupported.
+ */
+const struct drm_format_info *drm_format_info(u32 format)
+{
+	const struct drm_format_info *info;
+
+	info = __drm_format_info(format);
+	WARN_ON(!info);
+	return info;
+}
 EXPORT_SYMBOL(drm_format_info);
 
 /**
diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
index d33411bd19b1..ee22dff0786e 100644
--- a/include/drm/drm_fourcc.h
+++ b/include/drm/drm_fourcc.h
@@ -45,6 +45,7 @@ struct drm_format_info {
 	u8 vsub;
 };
 
+const struct drm_format_info *__drm_format_info(u32 format);
 const struct drm_format_info *drm_format_info(u32 format);
 void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth, int *bpp);
 int drm_format_num_planes(uint32_t format);
-- 
Regards,

Laurent Pinchart

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Re: [PATCH v2 2/5] drm: Centralize format information

[Eric Engestrom]

On Wed, Jun 08, 2016 at 02:35:35AM +0300, Laurent Pinchart wrote:
> Various pieces of information about DRM formats (number of planes, color
> depth, chroma subsampling, ...) are scattered across different helper
> functions in the DRM core. Callers of those functions often need to
> access more than a single parameter of the format, leading to
> inefficiencies due to multiple lookups.
> 
> Centralize all format information in a data structure and create a
> function to look up information based on the format 4CC.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/gpu/drm/drm_fourcc.c | 84 ++++++++++++++++++++++++++++++++++++++++++++
>  include/drm/drm_fourcc.h     | 21 +++++++++++
>  2 files changed, 105 insertions(+)
> 

[snip]

> diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
> index 7f90a396cf2b..d33411bd19b1 100644
> --- a/include/drm/drm_fourcc.h
> +++ b/include/drm/drm_fourcc.h
> @@ -25,6 +25,27 @@
>  #include <linux/types.h>
>  #include <uapi/drm/drm_fourcc.h>
>  
> +/**
> + * struct drm_format_info - information about a DRM format
> + * @format: 4CC format identifier (DRM_FORMAT_*)
> + * @depth: color depth (number of bits per pixel excluding padding bits)
> + * @bpp: number of bits per pixel including padding
> + * @num_planes: number of color planes (1 to 3)
> + * @cpp: number of bytes per pixel (per plane)
> + * @hsub: horizontal chroma subsampling factor
> + * @vsub: vertical chroma subsampling factor
> + */
> +struct drm_format_info {
> +	u32 format;
> +	u8 depth;
> +	u8 bpp;

I think `bpp` is redundant here: it's always `cpp[0] << 3`, except when
ignored (yuv formats), which `depth` already indicates by being 0.

Unless I missed something, the only change required to drop this field
would be in patch #3, in drm_fb_get_bpp_depth():

	*bpp = info->bpp;

becomes:

	*bpp = info->depth ? info->cpp[0] << 3 : 0;

I'm not really opposed to it being here if someone else finds it useful
though, so either way, the series is:
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>

> +	u8 num_planes;
> +	u8 cpp[3];
> +	u8 hsub;
> +	u8 vsub;
> +};
> +
> +const struct drm_format_info *drm_format_info(u32 format);
>  void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth, int *bpp);
>  int drm_format_num_planes(uint32_t format);
>  int drm_format_plane_cpp(uint32_t format, int plane);
> -- 
> Regards,
> 
> Laurent Pinchart
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
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Re: [PATCH v2 2/5] drm: Centralize format information

[Laurent Pinchart]

Hi Eric,

On Wednesday 08 Jun 2016 11:27:32 Eric Engestrom wrote:
> On Wed, Jun 08, 2016 at 02:35:35AM +0300, Laurent Pinchart wrote:
> > Various pieces of information about DRM formats (number of planes, color
> > depth, chroma subsampling, ...) are scattered across different helper
> > functions in the DRM core. Callers of those functions often need to
> > access more than a single parameter of the format, leading to
> > inefficiencies due to multiple lookups.
> > 
> > Centralize all format information in a data structure and create a
> > function to look up information based on the format 4CC.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> > 
> >  drivers/gpu/drm/drm_fourcc.c | 84 +++++++++++++++++++++++++++++++++++++++
> >  include/drm/drm_fourcc.h     | 21 +++++++++++
> >  2 files changed, 105 insertions(+)
> 
> [snip]
> 
> > diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
> > index 7f90a396cf2b..d33411bd19b1 100644
> > --- a/include/drm/drm_fourcc.h
> > +++ b/include/drm/drm_fourcc.h
> > @@ -25,6 +25,27 @@
> > 
> >  #include <linux/types.h>
> >  #include <uapi/drm/drm_fourcc.h>
> > 
> > +/**
> > + * struct drm_format_info - information about a DRM format
> > + * @format: 4CC format identifier (DRM_FORMAT_*)
> > + * @depth: color depth (number of bits per pixel excluding padding bits)
> > + * @bpp: number of bits per pixel including padding
> > + * @num_planes: number of color planes (1 to 3)
> > + * @cpp: number of bytes per pixel (per plane)
> > + * @hsub: horizontal chroma subsampling factor
> > + * @vsub: vertical chroma subsampling factor
> > + */
> > +struct drm_format_info {
> > +	u32 format;
> > +	u8 depth;
> > +	u8 bpp;
> 
> I think `bpp` is redundant here: it's always `cpp[0] << 3`, except when
> ignored (yuv formats), which `depth` already indicates by being 0.
> 
> Unless I missed something, the only change required to drop this field
> would be in patch #3, in drm_fb_get_bpp_depth():
> 
> 	*bpp = info->bpp;
> 
> becomes:
> 
> 	*bpp = info->depth ? info->cpp[0] << 3 : 0;

I agree with you, it's redundant. I'll remove it, and will also patch callers 
to user drm_format_cpp() instead of drm_fb_get_bpp_depth() where applicable.

> I'm not really opposed to it being here if someone else finds it useful
> though, so either way, the series is:
> Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
> 
> > +	u8 num_planes;
> > +	u8 cpp[3];
> > +	u8 hsub;
> > +	u8 vsub;
> > +};
> > +
> > +const struct drm_format_info *drm_format_info(u32 format);
> > 
> >  void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth, int
> >  *bpp);
> >  int drm_format_num_planes(uint32_t format);
> >  int drm_format_plane_cpp(uint32_t format, int plane);

-- 
Regards,

Laurent Pinchart

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