drm: sti: add Mixer

Mixer hardware IP is responsible of mixing the different inputs layers.
Z-order is managed by the mixer.
We could 2 mixers: one for main path and one for auxillary path

Mixers are part of Compositor hardware block

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/sti/sti_mixer.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) STMicroelectronics SA 2014
+ * Authors: Benjamin Gaignard <benjamin.gaignard@st.com>
+ *          Fabien Dessenne <fabien.dessenne@st.com>
+ *          for STMicroelectronics.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#ifndef _STI_MIXER_H_
+#define _STI_MIXER_H_
+
+#include <drm/drmP.h>
+
+#include "sti_layer.h"
+
+#define to_sti_mixer(x) container_of(x, struct sti_mixer, drm_crtc)
+
+/**
+ * STI Mixer subdevice structure
+ *
+ * @dev: driver device
+ * @regs: mixer registers
+ * @id: id of the mixer
+ * @drm_crtc: crtc object link to the mixer
+ * @pending_event: set if a flip event is pending on crtc
+ */
+struct sti_mixer {
+	struct device *dev;
+	void __iomem *regs;
+	int id;
+	struct drm_crtc	drm_crtc;
+	struct drm_pending_vblank_event *pending_event;
+};
+
+const char *sti_mixer_to_str(struct sti_mixer *mixer);
+
+struct sti_mixer *sti_mixer_create(struct device *dev, int id,
+		void __iomem *baseaddr);
+
+int sti_mixer_set_layer_status(struct sti_mixer *mixer,
+		struct sti_layer *layer, bool status);
+int sti_mixer_set_layer_depth(struct sti_mixer *mixer, struct sti_layer *layer);
+int sti_mixer_active_video_area(struct sti_mixer *mixer,
+		struct drm_display_mode *mode);
+
+void sti_mixer_set_background_status(struct sti_mixer *mixer, bool enable);
+
+/* depth in Cross-bar control = z order */
+#define GAM_MIXER_NB_DEPTH_LEVEL 7
+
+#define STI_MIXER_MAIN 0
+#define STI_MIXER_AUX  1
+
+#endif