drm: Plumb modifiers through plane init

This is the plumbing for supporting fb modifiers on planes. Modifiers
have already been introduced to some extent, but this series will extend
this to allow querying modifiers per plane. Based on this, the client to
enable optimal modifications for framebuffers.

This patch simply allows the DRM drivers to initialize their list of
supported modifiers upon initializing the plane.

v2: A minor addition from Daniel

v3:
* Updated commit message
* s/INVALID/DRM_FORMAT_MOD_INVALID (Liviu)
* Remove some excess newlines (Liviu)
* Update comment for > 64 modifiers (Liviu)

v4: Minor comment adjustments (Liviu)

v5: Some new platforms added due to rebase

v6: Add some missed plane inits (or maybe they're new - who knows at
this point) (Daniel)

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Daniel Stone <daniels@collabora.com> (v2)
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Stone <daniels@collabora.com>

3 files changed, 33 insertions, 1 deletions

diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
index 9ab3e7044812..9d2cc3b11ae7 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -392,6 +392,22 @@ struct drm_plane_funcs {
 	 */
 	void (*atomic_print_state)(struct drm_printer *p,
 				   const struct drm_plane_state *state);
+
+	/**
+	 * @format_mod_supported:
+	 *
+	 * This optional hook is used for the DRM to determine if the given
+	 * format/modifier combination is valid for the plane. This allows the
+	 * DRM to generate the correct format bitmask (which formats apply to
+	 * which modifier).
+	 *
+	 * Returns:
+	 *
+	 * True if the given modifier is valid for that format on the plane.
+	 * False otherwise.
+	 */
+	bool (*format_mod_supported)(struct drm_plane *plane, uint32_t format,
+				     uint64_t modifier);
 };
 
 /**
@@ -487,6 +503,9 @@ struct drm_plane {
 	unsigned int format_count;
 	bool format_default;
 
+	uint64_t *modifiers;
+	unsigned int modifier_count;
+
 	struct drm_crtc *crtc;
 	struct drm_framebuffer *fb;
 
@@ -527,13 +546,14 @@ struct drm_plane {
 
 #define obj_to_plane(x) container_of(x, struct drm_plane, base)
 
-__printf(8, 9)
+__printf(9, 10)
 int drm_universal_plane_init(struct drm_device *dev,
 			     struct drm_plane *plane,
 			     uint32_t possible_crtcs,
 			     const struct drm_plane_funcs *funcs,
 			     const uint32_t *formats,
 			     unsigned int format_count,
+			     const uint64_t *format_modifiers,
 			     enum drm_plane_type type,
 			     const char *name, ...);
 int drm_plane_init(struct drm_device *dev,
diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple_kms_helper.h
index 2d36538e4a17..6d9adbb46293 100644
--- a/include/drm/drm_simple_kms_helper.h
+++ b/include/drm/drm_simple_kms_helper.h
@@ -122,6 +122,7 @@ int drm_simple_display_pipe_init(struct drm_device *dev,
 			struct drm_simple_display_pipe *pipe,
 			const struct drm_simple_display_pipe_funcs *funcs,
 			const uint32_t *formats, unsigned int format_count,
+			const uint64_t *format_modifiers,
 			struct drm_connector *connector);
 
 #endif /* __LINUX_DRM_SIMPLE_KMS_HELPER_H */
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 7586c46f68bf..76c9101a7fc6 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -185,6 +185,8 @@ extern "C" {
 #define DRM_FORMAT_MOD_VENDOR_BROADCOM 0x07
 /* add more to the end as needed */
 
+#define DRM_FORMAT_RESERVED	      ((1ULL << 56) - 1)
+
 #define fourcc_mod_code(vendor, val) \
 	((((__u64)DRM_FORMAT_MOD_VENDOR_## vendor) << 56) | (val & 0x00ffffffffffffffULL))
 
@@ -197,6 +199,15 @@ extern "C" {
  */
 
 /*
+ * Invalid Modifier
+ *
+ * This modifier can be used as a sentinel to terminate the format modifiers
+ * list, or to initialize a variable with an invalid modifier. It might also be
+ * used to report an error back to userspace for certain APIs.
+ */
+#define DRM_FORMAT_MOD_INVALID	fourcc_mod_code(NONE, DRM_FORMAT_RESERVED)
+
+/*
  * Linear Layout
  *
  * Just plain linear layout. Note that this is different from no specifying any