[media] v4l: vsp1: Add histogram support

The histogram common code will be used to implement support for both the
HGO and HGT histogram computation engines.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/Kconfig

@@ -420,6 +420,7 @@ config VIDEO_RENESAS_VSP1
 	depends on (ARCH_RENESAS && OF) || COMPILE_TEST
 	depends on (!ARM64 && !VIDEO_RENESAS_FCP) || VIDEO_RENESAS_FCP
 	select VIDEOBUF2_DMA_CONTIG
+	select VIDEOBUF2_VMALLOC
 	---help---
 	  This is a V4L2 driver for the Renesas VSP1 video processing engine.
 

drivers/media/platform/vsp1/Makefile

@@ -3,6 +3,7 @@ vsp1-y					+= vsp1_dl.o vsp1_drm.o vsp1_video.o
 vsp1-y					+= vsp1_rpf.o vsp1_rwpf.o vsp1_wpf.o
 vsp1-y					+= vsp1_clu.o vsp1_hsit.o vsp1_lut.o
 vsp1-y					+= vsp1_bru.o vsp1_sru.o vsp1_uds.o
+vsp1-y					+= vsp1_histo.o
 vsp1-y					+= vsp1_lif.o
 
 obj-$(CONFIG_VIDEO_RENESAS_VSP1)	+= vsp1.o

drivers/media/platform/vsp1/vsp1_histo.h

+/*
+ * vsp1_histo.h  --  R-Car VSP1 Histogram API
+ *
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ * Copyright (C) 2016 Laurent Pinchart
+ *
+ * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#ifndef __VSP1_HISTO_H__
+#define __VSP1_HISTO_H__
+
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+
+#include <media/media-entity.h>
+#include <media/v4l2-dev.h>
+#include <media/videobuf2-v4l2.h>
+
+#include "vsp1_entity.h"
+
+struct vsp1_device;
+struct vsp1_pipeline;
+
+#define HISTO_PAD_SINK				0
+#define HISTO_PAD_SOURCE			1
+
+struct vsp1_histogram_buffer {
+	struct vb2_v4l2_buffer buf;
+	struct list_head queue;
+	void *addr;
+};
+
+struct vsp1_histogram {
+	struct vsp1_pipeline *pipe;
+
+	struct vsp1_entity entity;
+	struct video_device video;
+	struct media_pad pad;
+
+	const u32 *formats;
+	unsigned int num_formats;
+	size_t data_size;
+	u32 meta_format;
+
+	struct mutex lock;
+	struct vb2_queue queue;
+
+	spinlock_t irqlock;
+	struct list_head irqqueue;
+
+	wait_queue_head_t wait_queue;
+	bool readout;
+};
+
+static inline struct vsp1_histogram *vdev_to_histo(struct video_device *vdev)
+{
+	return container_of(vdev, struct vsp1_histogram, video);
+}
+
+static inline struct vsp1_histogram *subdev_to_histo(struct v4l2_subdev *subdev)
+{
+	return container_of(subdev, struct vsp1_histogram, entity.subdev);
+}
+
+int vsp1_histogram_init(struct vsp1_device *vsp1, struct vsp1_histogram *histo,
+			enum vsp1_entity_type type, const char *name,
+			const struct vsp1_entity_operations *ops,
+			const unsigned int *formats, unsigned int num_formats,
+			size_t data_size, u32 meta_format);
+void vsp1_histogram_destroy(struct vsp1_entity *entity);
+
+struct vsp1_histogram_buffer *
+vsp1_histogram_buffer_get(struct vsp1_histogram *histo);
+void vsp1_histogram_buffer_complete(struct vsp1_histogram *histo,
+				    struct vsp1_histogram_buffer *buf,
+				    size_t size);
+
+#endif /* __VSP1_HISTO_H__ */