target/linux/bcm27xx/patches-5.4/950-0227-drm-vc4-Expose-the-format-modifiers-for-firmware-kms.patch

From c27d4bbba9593a6ded8f482610a0247da66d78a9 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Mon, 18 Mar 2019 16:38:32 -0700
Subject: [PATCH] drm/vc4: Expose the format modifiers for firmware
 kms.

This should technically not expose VC4_T_TILED on pi4.  However, if we
don't expose anything, then userspace will assume that display can
handle whatever modifiers 3d can do (UIF on 2711).  By exposing a
list, that will get intersected with what 3D can do so that we get T
tiling for display on 2710 and linear on 2711.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/vc4/vc4_firmware_kms.c | 33 +++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/vc4/vc4_firmware_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_firmware_kms.c
@@ -281,6 +281,27 @@ static void vc4_plane_destroy(struct drm
 	drm_plane_cleanup(plane);
 }
 
+static bool vc4_fkms_format_mod_supported(struct drm_plane *plane,
+					  uint32_t format,
+					  uint64_t modifier)
+{
+	/* Support T_TILING for RGB formats only. */
+	switch (format) {
+	case DRM_FORMAT_XRGB8888:
+	case DRM_FORMAT_ARGB8888:
+		switch (modifier) {
+		case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
+		case DRM_FORMAT_MOD_LINEAR:
+		case DRM_FORMAT_MOD_BROADCOM_UIF:
+			return true;
+		default:
+			return false;
+		}
+	default:
+		return false;
+	}
+}
+
 static const struct drm_plane_funcs vc4_plane_funcs = {
 	.update_plane = drm_atomic_helper_update_plane,
 	.disable_plane = drm_atomic_helper_disable_plane,
@@ -289,6 +310,7 @@ static const struct drm_plane_funcs vc4_
 	.reset = drm_atomic_helper_plane_reset,
 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
+	.format_mod_supported = vc4_fkms_format_mod_supported,
 };
 
 static const struct drm_plane_helper_funcs vc4_primary_plane_helper_funcs = {
@@ -316,6 +338,14 @@ static struct drm_plane *vc4_fkms_plane_
 	u32 argb8888 = DRM_FORMAT_ARGB8888;
 	int ret = 0;
 	bool primary = (type == DRM_PLANE_TYPE_PRIMARY);
+	static const uint64_t modifiers[] = {
+		DRM_FORMAT_MOD_LINEAR,
+		/* VC4_T_TILED should come after linear, because we
+		 * would prefer to scan out linear (less bus traffic).
+		 */
+		DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED,
+		DRM_FORMAT_MOD_INVALID,
+	};
 
 	vc4_plane = devm_kzalloc(dev->dev, sizeof(*vc4_plane),
 				 GFP_KERNEL);
@@ -327,7 +357,8 @@ static struct drm_plane *vc4_fkms_plane_
 	plane = &vc4_plane->base;
 	ret = drm_universal_plane_init(dev, plane, 0xff,
 				       &vc4_plane_funcs,
-				       primary ? &xrgb8888 : &argb8888, 1, NULL,
+				       primary ? &xrgb8888 : &argb8888, 1,
+				       modifiers,
 				       type, primary ? "primary" : "cursor");
 
 	if (type == DRM_PLANE_TYPE_PRIMARY) {