drm/vc4: Implement atomic_print_state for HVS channel state

The HVS state configuration is useful when debugging what's going on in
the vc4 hardware pipeline. Add an implementation of .atomic_print_state.
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220328124304.2309418-5-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_kms.c

@@ -701,9 +701,26 @@ static void vc4_hvs_channels_destroy_state(struct drm_private_obj *obj,
 	kfree(hvs_state);
 }
 
+static void vc4_hvs_channels_print_state(struct drm_printer *p,
+					 const struct drm_private_state *state)
+{
+	struct vc4_hvs_state *hvs_state = to_vc4_hvs_state(state);
+	unsigned int i;
+
+	drm_printf(p, "HVS State\n");
+	drm_printf(p, "\tCore Clock Rate: %lu\n", hvs_state->core_clock_rate);
+
+	for (i = 0; i < HVS_NUM_CHANNELS; i++) {
+		drm_printf(p, "\tChannel %d\n", i);
+		drm_printf(p, "\t\tin use=%d\n", hvs_state->fifo_state[i].in_use);
+		drm_printf(p, "\t\tload=%lu\n", hvs_state->fifo_state[i].fifo_load);
+	}
+}
+
 static const struct drm_private_state_funcs vc4_hvs_state_funcs = {
 	.atomic_duplicate_state = vc4_hvs_channels_duplicate_state,
 	.atomic_destroy_state = vc4_hvs_channels_destroy_state,
+	.atomic_print_state = vc4_hvs_channels_print_state,
 };
 
 static void vc4_hvs_channels_obj_fini(struct drm_device *dev, void *unused)