[PATCHv4 02/36] drm/core: Add afbc helper functions

[Andrzej Pietrasiewicz]

Add checking if a modifier is afbc and getting afbc block size.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p at collabora.com>
---
 drivers/gpu/drm/drm_fourcc.c | 53 ++++++++++++++++++++++++++++++++++++
 include/drm/drm_fourcc.h     |  4 +++
 2 files changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index b234bfaeda06..d14dd7c86020 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -29,6 +29,7 @@
 
 #include <drm/drm_device.h>
 #include <drm/drm_fourcc.h>
+#include <drm/drm_print.h>
 
 static char printable_char(int c)
 {
@@ -393,3 +394,55 @@ uint64_t drm_format_info_min_pitch(const struct drm_format_info *info,
 			    drm_format_info_block_height(info, plane));
 }
 EXPORT_SYMBOL(drm_format_info_min_pitch);
+
+/**
+ * drm_is_afbc - test if the modifier describes an afbc buffer
+ * @modifier - modifier to be tested
+ *
+ * Returns: true if the modifier describes an afbc buffer
+ */
+bool drm_is_afbc(u64 modifier)
+{
+	/* is it ARM AFBC? */
+	if ((modifier & DRM_FORMAT_MOD_ARM_AFBC(0)) == 0)
+		return false;
+
+	/* Block size must be known */
+	if ((modifier & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) == 0)
+		return false;
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(drm_is_afbc);
+
+/**
+ * drm_afbc_get_superblock_wh - extract afbc block width/height from modifier
+ * @modifier: the modifier to be looked at
+ * @w: address of a place to store the block width
+ * @h: address of a place to store the block height
+ *
+ * Returns: true if the modifier describes a supported block size
+ */
+bool drm_afbc_get_superblock_wh(u64 modifier, u32 *w, u32 *h)
+{
+	switch (modifier & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) {
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16:
+		*w = 16;
+		*h = 16;
+		break;
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8:
+		*w = 32;
+		*h = 8;
+		break;
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4:
+		/* fall through */
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4:
+		/* fall through */
+	default:
+		DRM_DEBUG_KMS("Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n",
+			      modifier & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK);
+		return false;
+	}
+	return true;
+}
+EXPORT_SYMBOL_GPL(drm_afbc_get_superblock_wh);
diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
index 306d1efeb5e0..7eb23062bf45 100644
--- a/include/drm/drm_fourcc.h
+++ b/include/drm/drm_fourcc.h
@@ -320,4 +320,8 @@ uint64_t drm_format_info_min_pitch(const struct drm_format_info *info,
 				   int plane, unsigned int buffer_width);
 const char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
 
+bool drm_is_afbc(u64 modifier);
+
+bool drm_afbc_get_superblock_wh(u64 modifier, u32 *w, u32 *h);
+
 #endif /* __DRM_FOURCC_H__ */
-- 
2.17.1