[PATCH] drm/v3d: Define the fourcc modifier for the Broadcom UIF format.
Eric Anholt
eric at anholt.net
Thu Jun 21 00:17:03 UTC 2018
This will be used by Mesa, and potentially other drivers in the
future, to describe tiled buffers.
Signed-off-by: Eric Anholt <eric at anholt.net>
---
include/uapi/drm/drm_fourcc.h | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 64bf67abff7e..d5e52350a3aa 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -464,6 +464,27 @@ extern "C" {
#define DRM_FORMAT_MOD_BROADCOM_SAND256 \
DRM_FORMAT_MOD_BROADCOM_SAND256_COL_HEIGHT(0)
+/* Broadcom UIF format
+ *
+ * This is the common format for the current Broadcom multimedia
+ * blocks, including V3D 3.x and newer, newer video codecs, and
+ * displays.
+ *
+ * The image consists of utiles (64b blocks), UIF blocks (2x2 utiles),
+ * and macroblocks (4x4 UIF blocks). Those 4x4 UIF block groups are
+ * stored in columns, with padding between the columns to ensure that
+ * moving from one column to the next doesn't hit the same SDRAM page
+ * bank.
+ *
+ * To calculate the padding, it is assumed that each hardware block
+ * and the software driving it knows the platform's SDRAM page size,
+ * number of banks, and XOR address, and that it's identical between
+ * all blocks using the format. This tiling modifier will use XOR as
+ * necessary to reduce the padding. If a hardware block can't do XOR,
+ * the assumption is that a no-XOR tiling modifier will be created.
+ */
+#define DRM_FORMAT_MOD_BROADCOM_UIF fourcc_mod_code(BROADCOM, 6)
+
#if defined(__cplusplus)
}
#endif
--
2.17.0
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