[media] v4l: omap4iss: Add support for OMAP4 camera interface - Video devices

This adds a very simplistic driver to utilize the CSI2A interface inside
the ISS subsystem in OMAP4, and dump the data to memory.
Check Documentation/video4linux/omap4_camera.txt for details.
This commit adds video devices support.
Signed-off-by: Sergio Aguirre <sergio.a.aguirre@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/staging/media/omap4iss/iss_video.h

+/*
+ * TI OMAP4 ISS V4L2 Driver - Generic video node
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ *
+ * Author: Sergio Aguirre <sergio.a.aguirre@gmail.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 OMAP4_ISS_VIDEO_H
+#define OMAP4_ISS_VIDEO_H
+
+#include <linux/v4l2-mediabus.h>
+#include <media/media-entity.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-fh.h>
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-dma-contig.h>
+
+#define ISS_VIDEO_DRIVER_NAME		"issvideo"
+#define ISS_VIDEO_DRIVER_VERSION	"0.0.2"
+
+struct iss_device;
+struct iss_video;
+struct v4l2_mbus_framefmt;
+struct v4l2_pix_format;
+
+/*
+ * struct iss_format_info - ISS media bus format information
+ * @code: V4L2 media bus format code
+ * @truncated: V4L2 media bus format code for the same format truncated to 10
+ *	bits. Identical to @code if the format is 10 bits wide or less.
+ * @uncompressed: V4L2 media bus format code for the corresponding uncompressed
+ *	format. Identical to @code if the format is not DPCM compressed.
+ * @flavor: V4L2 media bus format code for the same pixel layout but
+ *	shifted to be 8 bits per pixel. =0 if format is not shiftable.
+ * @pixelformat: V4L2 pixel format FCC identifier
+ * @bpp: Bits per pixel
+ */
+struct iss_format_info {
+	enum v4l2_mbus_pixelcode code;
+	enum v4l2_mbus_pixelcode truncated;
+	enum v4l2_mbus_pixelcode uncompressed;
+	enum v4l2_mbus_pixelcode flavor;
+	u32 pixelformat;
+	unsigned int bpp;
+};
+
+enum iss_pipeline_stream_state {
+	ISS_PIPELINE_STREAM_STOPPED = 0,
+	ISS_PIPELINE_STREAM_CONTINUOUS = 1,
+	ISS_PIPELINE_STREAM_SINGLESHOT = 2,
+};
+
+enum iss_pipeline_state {
+	/* The stream has been started on the input video node. */
+	ISS_PIPELINE_STREAM_INPUT = 1,
+	/* The stream has been started on the output video node. */
+	ISS_PIPELINE_STREAM_OUTPUT = (1 << 1),
+	/* At least one buffer is queued on the input video node. */
+	ISS_PIPELINE_QUEUE_INPUT = (1 << 2),
+	/* At least one buffer is queued on the output video node. */
+	ISS_PIPELINE_QUEUE_OUTPUT = (1 << 3),
+	/* The input entity is idle, ready to be started. */
+	ISS_PIPELINE_IDLE_INPUT = (1 << 4),
+	/* The output entity is idle, ready to be started. */
+	ISS_PIPELINE_IDLE_OUTPUT = (1 << 5),
+	/* The pipeline is currently streaming. */
+	ISS_PIPELINE_STREAM = (1 << 6),
+};
+
+/*
+ * struct iss_pipeline - An OMAP4 ISS hardware pipeline
+ * @error: A hardware error occurred during capture
+ */
+struct iss_pipeline {
+	struct media_pipeline pipe;
+	spinlock_t lock;		/* Pipeline state and queue flags */
+	unsigned int state;
+	enum iss_pipeline_stream_state stream_state;
+	struct iss_video *input;
+	struct iss_video *output;
+	atomic_t frame_number;
+	bool do_propagation; /* of frame number */
+	bool error;
+	struct v4l2_fract max_timeperframe;
+	struct v4l2_subdev *external;
+	unsigned int external_rate;
+	int external_bpp;
+};
+
+#define to_iss_pipeline(__e) \
+	container_of((__e)->pipe, struct iss_pipeline, pipe)
+
+static inline int iss_pipeline_ready(struct iss_pipeline *pipe)
+{
+	return pipe->state == (ISS_PIPELINE_STREAM_INPUT |
+			       ISS_PIPELINE_STREAM_OUTPUT |
+			       ISS_PIPELINE_QUEUE_INPUT |
+			       ISS_PIPELINE_QUEUE_OUTPUT |
+			       ISS_PIPELINE_IDLE_INPUT |
+			       ISS_PIPELINE_IDLE_OUTPUT);
+}
+
+/*
+ * struct iss_buffer - ISS buffer
+ * @buffer: ISS video buffer
+ * @iss_addr: Physical address of the buffer.
+ */
+struct iss_buffer {
+	/* common v4l buffer stuff -- must be first */
+	struct vb2_buffer	vb;
+	struct list_head	list;
+	dma_addr_t iss_addr;
+};
+
+#define to_iss_buffer(buf)	container_of(buf, struct iss_buffer, buffer)
+
+enum iss_video_dmaqueue_flags {
+	/* Set if DMA queue becomes empty when ISS_PIPELINE_STREAM_CONTINUOUS */
+	ISS_VIDEO_DMAQUEUE_UNDERRUN = (1 << 0),
+	/* Set when queuing buffer to an empty DMA queue */
+	ISS_VIDEO_DMAQUEUE_QUEUED = (1 << 1),
+};
+
+#define iss_video_dmaqueue_flags_clr(video)	\
+			({ (video)->dmaqueue_flags = 0; })
+
+/*
+ * struct iss_video_operations - ISS video operations
+ * @queue:	Resume streaming when a buffer is queued. Called on VIDIOC_QBUF
+ *		if there was no buffer previously queued.
+ */
+struct iss_video_operations {
+	int(*queue)(struct iss_video *video, struct iss_buffer *buffer);
+};
+
+struct iss_video {
+	struct video_device video;
+	enum v4l2_buf_type type;
+	struct media_pad pad;
+
+	struct mutex mutex;		/* format and crop settings */
+	atomic_t active;
+
+	struct iss_device *iss;
+
+	unsigned int capture_mem;
+	unsigned int bpl_alignment;	/* alignment value */
+	unsigned int bpl_zero_padding;	/* whether the alignment is optional */
+	unsigned int bpl_max;		/* maximum bytes per line value */
+	unsigned int bpl_value;		/* bytes per line value */
+	unsigned int bpl_padding;	/* padding at end of line */
+
+	/* Entity video node streaming */
+	unsigned int streaming:1;
+
+	/* Pipeline state */
+	struct iss_pipeline pipe;
+	struct mutex stream_lock;	/* pipeline and stream states */
+
+	/* Video buffers queue */
+	struct vb2_queue *queue;
+	spinlock_t qlock;	/* Spinlock for dmaqueue */
+	struct list_head dmaqueue;
+	enum iss_video_dmaqueue_flags dmaqueue_flags;
+	struct vb2_alloc_ctx *alloc_ctx;
+
+	const struct iss_video_operations *ops;
+};
+
+#define to_iss_video(vdev)	container_of(vdev, struct iss_video, video)
+
+struct iss_video_fh {
+	struct v4l2_fh vfh;
+	struct iss_video *video;
+	struct vb2_queue queue;
+	struct v4l2_format format;
+	struct v4l2_fract timeperframe;
+};
+
+#define to_iss_video_fh(fh)	container_of(fh, struct iss_video_fh, vfh)
+#define iss_video_queue_to_iss_video_fh(q) \
+				container_of(q, struct iss_video_fh, queue)
+
+int omap4iss_video_init(struct iss_video *video, const char *name);
+void omap4iss_video_cleanup(struct iss_video *video);
+int omap4iss_video_register(struct iss_video *video,
+			    struct v4l2_device *vdev);
+void omap4iss_video_unregister(struct iss_video *video);
+struct iss_buffer *omap4iss_video_buffer_next(struct iss_video *video);
+struct media_pad *omap4iss_video_remote_pad(struct iss_video *video);
+
+const struct iss_format_info *
+omap4iss_video_format_info(enum v4l2_mbus_pixelcode code);
+
+#endif /* OMAP4_ISS_VIDEO_H */