media: drm: rcar-du: Add support for CRC computation

Implement CRC computation configuration and reporting through the DRM
debugfs-based CRC API. The CRC source can be configured to any input
plane or the pipeline output.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/gpu/drm/rcar-du/rcar_du_crtc.c

@@ -691,6 +691,52 @@ static const struct drm_crtc_helper_funcs crtc_helper_funcs = {
 	.atomic_disable = rcar_du_crtc_atomic_disable,
 };
 
+static struct drm_crtc_state *
+rcar_du_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
+{
+	struct rcar_du_crtc_state *state;
+	struct rcar_du_crtc_state *copy;
+
+	if (WARN_ON(!crtc->state))
+		return NULL;
+
+	state = to_rcar_crtc_state(crtc->state);
+	copy = kmemdup(state, sizeof(*state), GFP_KERNEL);
+	if (copy == NULL)
+		return NULL;
+
+	__drm_atomic_helper_crtc_duplicate_state(crtc, &copy->state);
+
+	return &copy->state;
+}
+
+static void rcar_du_crtc_atomic_destroy_state(struct drm_crtc *crtc,
+					      struct drm_crtc_state *state)
+{
+	__drm_atomic_helper_crtc_destroy_state(state);
+	kfree(to_rcar_crtc_state(state));
+}
+
+static void rcar_du_crtc_reset(struct drm_crtc *crtc)
+{
+	struct rcar_du_crtc_state *state;
+
+	if (crtc->state) {
+		rcar_du_crtc_atomic_destroy_state(crtc, crtc->state);
+		crtc->state = NULL;
+	}
+
+	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	if (state == NULL)
+		return;
+
+	state->crc.source = VSP1_DU_CRC_NONE;
+	state->crc.index = 0;
+
+	crtc->state = &state->state;
+	crtc->state->crtc = crtc;
+}
+
 static int rcar_du_crtc_enable_vblank(struct drm_crtc *crtc)
 {
 	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
@@ -710,15 +756,111 @@ static void rcar_du_crtc_disable_vblank(struct drm_crtc *crtc)
 	rcrtc->vblank_enable = false;
 }
 
-static const struct drm_crtc_funcs crtc_funcs = {
-	.reset = drm_atomic_helper_crtc_reset,
+static int rcar_du_crtc_set_crc_source(struct drm_crtc *crtc,
+				       const char *source_name,
+				       size_t *values_cnt)
+{
+	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_crtc_state *crtc_state;
+	struct drm_atomic_state *state;
+	enum vsp1_du_crc_source source;
+	unsigned int index = 0;
+	unsigned int i;
+	int ret;
+
+	/*
+	 * Parse the source name. Supported values are "plane%u" to compute the
+	 * CRC on an input plane (%u is the plane ID), and "auto" to compute the
+	 * CRC on the composer (VSP) output.
+	 */
+	if (!source_name) {
+		source = VSP1_DU_CRC_NONE;
+	} else if (!strcmp(source_name, "auto")) {
+		source = VSP1_DU_CRC_OUTPUT;
+	} else if (strstarts(source_name, "plane")) {
+		source = VSP1_DU_CRC_PLANE;
+
+		ret = kstrtouint(source_name + strlen("plane"), 10, &index);
+		if (ret < 0)
+			return ret;
+
+		for (i = 0; i < rcrtc->vsp->num_planes; ++i) {
+			if (index == rcrtc->vsp->planes[i].plane.base.id) {
+				index = i;
+				break;
+			}
+		}
+
+		if (i >= rcrtc->vsp->num_planes)
+			return -EINVAL;
+	} else {
+		return -EINVAL;
+	}
+
+	*values_cnt = 1;
+
+	/* Perform an atomic commit to set the CRC source. */
+	drm_modeset_acquire_init(&ctx, 0);
+
+	state = drm_atomic_state_alloc(crtc->dev);
+	if (!state) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	state->acquire_ctx = &ctx;
+
+retry:
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (!IS_ERR(crtc_state)) {
+		struct rcar_du_crtc_state *rcrtc_state;
+
+		rcrtc_state = to_rcar_crtc_state(crtc_state);
+		rcrtc_state->crc.source = source;
+		rcrtc_state->crc.index = index;
+
+		ret = drm_atomic_commit(state);
+	} else {
+		ret = PTR_ERR(crtc_state);
+	}
+
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		drm_modeset_backoff(&ctx);
+		goto retry;
+	}
+
+	drm_atomic_state_put(state);
+
+unlock:
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	return 0;
+}
+
+static const struct drm_crtc_funcs crtc_funcs_gen2 = {
+	.reset = rcar_du_crtc_reset,
+	.destroy = drm_crtc_cleanup,
+	.set_config = drm_atomic_helper_set_config,
+	.page_flip = drm_atomic_helper_page_flip,
+	.atomic_duplicate_state = rcar_du_crtc_atomic_duplicate_state,
+	.atomic_destroy_state = rcar_du_crtc_atomic_destroy_state,
+	.enable_vblank = rcar_du_crtc_enable_vblank,
+	.disable_vblank = rcar_du_crtc_disable_vblank,
+};
+
+static const struct drm_crtc_funcs crtc_funcs_gen3 = {
+	.reset = rcar_du_crtc_reset,
 	.destroy = drm_crtc_cleanup,
 	.set_config = drm_atomic_helper_set_config,
 	.page_flip = drm_atomic_helper_page_flip,
-	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
-	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+	.atomic_duplicate_state = rcar_du_crtc_atomic_duplicate_state,
+	.atomic_destroy_state = rcar_du_crtc_atomic_destroy_state,
 	.enable_vblank = rcar_du_crtc_enable_vblank,
 	.disable_vblank = rcar_du_crtc_disable_vblank,
+	.set_crc_source = rcar_du_crtc_set_crc_source,
 };
 
 /* -----------------------------------------------------------------------------
@@ -821,8 +963,10 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 	else
 		primary = &rgrp->planes[index % 2].plane;
 
-	ret = drm_crtc_init_with_planes(rcdu->ddev, crtc, primary,
-					NULL, &crtc_funcs, NULL);
+	ret = drm_crtc_init_with_planes(rcdu->ddev, crtc, primary, NULL,
+					rcdu->info->gen <= 2 ?
+					&crtc_funcs_gen2 : &crtc_funcs_gen3,
+					NULL);
 	if (ret < 0)
 		return ret;
 

drivers/gpu/drm/rcar-du/rcar_du_crtc.h

@@ -21,6 +21,8 @@
 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
 
+#include <media/vsp1.h>
+
 struct rcar_du_group;
 struct rcar_du_vsp;
 
@@ -69,6 +71,19 @@ struct rcar_du_crtc {
 
 #define to_rcar_crtc(c)	container_of(c, struct rcar_du_crtc, crtc)
 
+/**
+ * struct rcar_du_crtc_state - Driver-specific CRTC state
+ * @state: base DRM CRTC state
+ * @crc: CRC computation configuration
+ */
+struct rcar_du_crtc_state {
+	struct drm_crtc_state state;
+
+	struct vsp1_du_crc_config crc;
+};
+
+#define to_rcar_crtc_state(s) container_of(s, struct rcar_du_crtc_state, state)
+
 enum rcar_du_output {
 	RCAR_DU_OUTPUT_DPAD0,
 	RCAR_DU_OUTPUT_DPAD1,

drivers/gpu/drm/rcar-du/rcar_du_vsp.c

@@ -40,6 +40,8 @@ static void rcar_du_vsp_complete(void *private, bool completed, u32 crc)
 
 	if (completed)
 		rcar_du_crtc_finish_page_flip(crtc);
+
+	drm_crtc_add_crc_entry(&crtc->crtc, false, 0, &crc);
 }
 
 void rcar_du_vsp_enable(struct rcar_du_crtc *crtc)
@@ -103,6 +105,10 @@ void rcar_du_vsp_atomic_begin(struct rcar_du_crtc *crtc)
 void rcar_du_vsp_atomic_flush(struct rcar_du_crtc *crtc)
 {
 	struct vsp1_du_atomic_pipe_config cfg = { { 0, } };
+	struct rcar_du_crtc_state *state;
+
+	state = to_rcar_crtc_state(crtc->crtc.state);
+	cfg.crc = state->crc;
 
 	vsp1_du_atomic_flush(crtc->vsp->vsp, crtc->vsp_pipe, &cfg);
 }