drm/msm/mdp4: Support NV12MT format in mdp4

Using fb modifier flag, support NV12MT format in MDP4.

v2:
- rework the modifier's description [Daniel Vetter's comment]
- drop .set_mode_config() callback [Rob Clark's comment]
v3:
- change VENDOR's name and restrict usage to NV12 [pointed by Daniel]
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/drm_crtc.c

@@ -3255,6 +3255,24 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
 				      r->modifier[i], i);
 			return -EINVAL;
 		}
+
+		/* modifier specific checks: */
+		switch (r->modifier[i]) {
+		case DRM_FORMAT_MOD_SAMSUNG_64_32_TILE:
+			/* NOTE: the pitch restriction may be lifted later if it turns
+			 * out that no hw has this restriction:
+			 */
+			if (r->pixel_format != DRM_FORMAT_NV12 ||
+					width % 128 || height % 32 ||
+					r->pitches[i] % 128) {
+				DRM_DEBUG_KMS("bad modifier data for plane %d\n", i);
+				return -EINVAL;
+			}
+			break;
+
+		default:
+			break;
+		}
 	}
 
 	for (i = num_planes; i < 4; i++) {

drivers/gpu/drm/msm/mdp/mdp4/mdp4_kms.c

@@ -119,6 +119,8 @@ static int mdp4_hw_init(struct msm_kms *kms)
 	if (mdp4_kms->rev > 1)
 		mdp4_write(mdp4_kms, REG_MDP4_RESET_STATUS, 1);
 
+	dev->mode_config.allow_fb_modifiers = true;
+
 out:
 	pm_runtime_put_sync(dev->dev);
 

drivers/gpu/drm/msm/mdp/mdp4/mdp4_plane.c

@@ -33,6 +33,21 @@ struct mdp4_plane {
 };
 #define to_mdp4_plane(x) container_of(x, struct mdp4_plane, base)
 
+/* MDP format helper functions */
+static inline
+enum mdp4_frame_format mdp4_get_frame_format(struct drm_framebuffer *fb)
+{
+	bool is_tile = false;
+
+	if (fb->modifier[1] == DRM_FORMAT_MOD_SAMSUNG_64_32_TILE)
+		is_tile = true;
+
+	if (fb->pixel_format == DRM_FORMAT_NV12 && is_tile)
+		return FRAME_TILE_YCBCR_420;
+
+	return FRAME_LINEAR;
+}
+
 static void mdp4_plane_set_scanout(struct drm_plane *plane,
 		struct drm_framebuffer *fb);
 static int mdp4_plane_mode_set(struct drm_plane *plane,
@@ -205,6 +220,7 @@ static int mdp4_plane_mode_set(struct drm_plane *plane,
 	uint32_t op_mode = 0;
 	uint32_t phasex_step = MDP4_VG_PHASE_STEP_DEFAULT;
 	uint32_t phasey_step = MDP4_VG_PHASE_STEP_DEFAULT;
+	enum mdp4_frame_format frame_type = mdp4_get_frame_format(fb);
 
 	if (!(crtc && fb)) {
 		DBG("%s: disabled!", mdp4_plane->name);
@@ -304,6 +320,7 @@ static int mdp4_plane_mode_set(struct drm_plane *plane,
 			MDP4_PIPE_SRC_FORMAT_UNPACK_COUNT(format->unpack_count - 1) |
 			MDP4_PIPE_SRC_FORMAT_FETCH_PLANES(format->fetch_type) |
 			MDP4_PIPE_SRC_FORMAT_CHROMA_SAMP(format->chroma_sample) |
+			MDP4_PIPE_SRC_FORMAT_FRAME_FORMAT(frame_type) |
 			COND(format->unpack_tight, MDP4_PIPE_SRC_FORMAT_UNPACK_TIGHT));
 
 	mdp4_write(mdp4_kms, REG_MDP4_PIPE_SRC_UNPACK(pipe),
@@ -324,6 +341,11 @@ static int mdp4_plane_mode_set(struct drm_plane *plane,
 	mdp4_write(mdp4_kms, REG_MDP4_PIPE_PHASEX_STEP(pipe), phasex_step);
 	mdp4_write(mdp4_kms, REG_MDP4_PIPE_PHASEY_STEP(pipe), phasey_step);
 
+	if (frame_type != FRAME_LINEAR)
+		mdp4_write(mdp4_kms, REG_MDP4_PIPE_SSTILE_FRAME_SIZE(pipe),
+				MDP4_PIPE_SSTILE_FRAME_SIZE_WIDTH(src_w) |
+				MDP4_PIPE_SSTILE_FRAME_SIZE_HEIGHT(src_h));
+
 	return 0;
 }
 

include/uapi/drm/drm_fourcc.h

@@ -207,4 +207,19 @@
  */
 #define I915_FORMAT_MOD_Yf_TILED fourcc_mod_code(INTEL, 3)
 
+/*
+ * Tiled, NV12MT, grouped in 64 (pixels) x 32 (lines) -sized macroblocks
+ *
+ * Macroblocks are laid in a Z-shape, and each pixel data is following the
+ * standard NV12 style.
+ * As for NV12, an image is the result of two frame buffers: one for Y,
+ * one for the interleaved Cb/Cr components (1/2 the height of the Y buffer).
+ * Alignment requirements are (for each buffer):
+ * - multiple of 128 pixels for the width
+ * - multiple of  32 pixels for the height
+ *
+ * For more information: see http://linuxtv.org/downloads/v4l-dvb-apis/re32.html
+ */
+#define DRM_FORMAT_MOD_SAMSUNG_64_32_TILE	fourcc_mod_code(SAMSUNG, 1)
+
 #endif /* DRM_FOURCC_H */