staging: Import the BCM2835 MMAL-based V4L2 camera driver.

- Supports raw YUV capture, preview, JPEG and H264.
- Uses videobuf2 for data transfer, using dma_buf.
- Uses 3.6.10 timestamping
- Camera power based on use
- Uses immutable input mode on video encoder

This code comes from the Raspberry Pi kernel tree (rpi-4.9.y) as of
a15ba877dab4e61ea3fc7b006e2a73828b083c52.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/media/platform/bcm2835/bcm2835-camera.h

+/*
+ * Broadcom BM2835 V4L2 driver
+ *
+ * Copyright © 2013 Raspberry Pi (Trading) Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * Authors: Vincent Sanders <vincent.sanders@collabora.co.uk>
+ *          Dave Stevenson <dsteve@broadcom.com>
+ *          Simon Mellor <simellor@broadcom.com>
+ *          Luke Diamand <luked@broadcom.com>
+ *
+ * core driver device
+ */
+
+#define V4L2_CTRL_COUNT 29 /* number of v4l controls */
+
+enum {
+	MMAL_COMPONENT_CAMERA = 0,
+	MMAL_COMPONENT_PREVIEW,
+	MMAL_COMPONENT_IMAGE_ENCODE,
+	MMAL_COMPONENT_VIDEO_ENCODE,
+	MMAL_COMPONENT_COUNT
+};
+
+enum {
+	MMAL_CAMERA_PORT_PREVIEW = 0,
+	MMAL_CAMERA_PORT_VIDEO,
+	MMAL_CAMERA_PORT_CAPTURE,
+	MMAL_CAMERA_PORT_COUNT
+};
+
+#define PREVIEW_LAYER      2
+
+extern int bcm2835_v4l2_debug;
+
+struct bm2835_mmal_dev {
+	/* v4l2 devices */
+	struct v4l2_device     v4l2_dev;
+	struct video_device    vdev;
+	struct mutex           mutex;
+
+	/* controls */
+	struct v4l2_ctrl_handler  ctrl_handler;
+	struct v4l2_ctrl          *ctrls[V4L2_CTRL_COUNT];
+	enum v4l2_scene_mode	  scene_mode;
+	struct mmal_colourfx      colourfx;
+	int                       hflip;
+	int                       vflip;
+	int			  red_gain;
+	int			  blue_gain;
+	enum mmal_parameter_exposuremode exposure_mode_user;
+	enum v4l2_exposure_auto_type exposure_mode_v4l2_user;
+	/* active exposure mode may differ if selected via a scene mode */
+	enum mmal_parameter_exposuremode exposure_mode_active;
+	enum mmal_parameter_exposuremeteringmode metering_mode;
+	unsigned int		  manual_shutter_speed;
+	bool			  exp_auto_priority;
+	bool manual_iso_enabled;
+	uint32_t iso;
+
+	/* allocated mmal instance and components */
+	struct vchiq_mmal_instance   *instance;
+	struct vchiq_mmal_component  *component[MMAL_COMPONENT_COUNT];
+	int camera_use_count;
+
+	struct v4l2_window overlay;
+
+	struct {
+		unsigned int     width;  /* width */
+		unsigned int     height;  /* height */
+		unsigned int     stride;  /* stride */
+		unsigned int     buffersize; /* buffer size with padding */
+		struct mmal_fmt  *fmt;
+		struct v4l2_fract timeperframe;
+
+		/* H264 encode bitrate */
+		int         encode_bitrate;
+		/* H264 bitrate mode. CBR/VBR */
+		int         encode_bitrate_mode;
+		/* H264 profile */
+		enum v4l2_mpeg_video_h264_profile enc_profile;
+		/* H264 level */
+		enum v4l2_mpeg_video_h264_level enc_level;
+		/* JPEG Q-factor */
+		int         q_factor;
+
+		struct vb2_queue	vb_vidq;
+
+		/* VC start timestamp for streaming */
+		s64         vc_start_timestamp;
+		/* Kernel start timestamp for streaming */
+		struct timeval kernel_start_ts;
+
+		struct vchiq_mmal_port  *port; /* port being used for capture */
+		/* camera port being used for capture */
+		struct vchiq_mmal_port  *camera_port;
+		/* component being used for encode */
+		struct vchiq_mmal_component *encode_component;
+		/* number of frames remaining which driver should capture */
+		unsigned int  frame_count;
+		/* last frame completion */
+		struct completion  frame_cmplt;
+
+	} capture;
+
+	unsigned int camera_num;
+	unsigned int max_width;
+	unsigned int max_height;
+	unsigned int rgb_bgr_swapped;
+};
+
+int bm2835_mmal_init_controls(
+			struct bm2835_mmal_dev *dev,
+			struct v4l2_ctrl_handler *hdl);
+
+int bm2835_mmal_set_all_camera_controls(struct bm2835_mmal_dev *dev);
+int set_framerate_params(struct bm2835_mmal_dev *dev);
+
+/* Debug helpers */
+
+#define v4l2_dump_pix_format(level, debug, dev, pix_fmt, desc)	\
+{	\
+	v4l2_dbg(level, debug, dev,	\
+"%s: w %u h %u field %u pfmt 0x%x bpl %u sz_img %u colorspace 0x%x priv %u\n", \
+		desc == NULL ? "" : desc,	\
+		(pix_fmt)->width, (pix_fmt)->height, (pix_fmt)->field,	\
+		(pix_fmt)->pixelformat, (pix_fmt)->bytesperline,	\
+		(pix_fmt)->sizeimage, (pix_fmt)->colorspace, (pix_fmt)->priv); \
+}
+#define v4l2_dump_win_format(level, debug, dev, win_fmt, desc)	\
+{	\
+	v4l2_dbg(level, debug, dev,	\
+"%s: w %u h %u l %u t %u  field %u chromakey %06X clip %p " \
+"clipcount %u bitmap %p\n", \
+		desc == NULL ? "" : desc,	\
+		(win_fmt)->w.width, (win_fmt)->w.height, \
+		(win_fmt)->w.left, (win_fmt)->w.top, \
+		(win_fmt)->field,	\
+		(win_fmt)->chromakey,	\
+		(win_fmt)->clips, (win_fmt)->clipcount,	\
+		(win_fmt)->bitmap); \
+}

drivers/staging/media/platform/bcm2835/mmal-common.h

+/*
+ * Broadcom BM2835 V4L2 driver
+ *
+ * Copyright © 2013 Raspberry Pi (Trading) Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * Authors: Vincent Sanders <vincent.sanders@collabora.co.uk>
+ *          Dave Stevenson <dsteve@broadcom.com>
+ *          Simon Mellor <simellor@broadcom.com>
+ *          Luke Diamand <luked@broadcom.com>
+ *
+ * MMAL structures
+ *
+ */
+
+#define MMAL_FOURCC(a, b, c, d) ((a) | (b << 8) | (c << 16) | (d << 24))
+#define MMAL_MAGIC MMAL_FOURCC('m', 'm', 'a', 'l')
+
+/** Special value signalling that time is not known */
+#define MMAL_TIME_UNKNOWN (1LL<<63)
+
+/* mapping between v4l and mmal video modes */
+struct mmal_fmt {
+	char  *name;
+	u32   fourcc;          /* v4l2 format id */
+	int   flags;           /* v4l2 flags field */
+	u32   mmal;
+	int   depth;
+	u32   mmal_component;  /* MMAL component index to be used to encode */
+	u32   ybbp;            /* depth of first Y plane for planar formats */
+};
+
+/* buffer for one video frame */
+struct mmal_buffer {
+	/* v4l buffer data -- must be first */
+	struct vb2_v4l2_buffer	vb;
+
+	/* list of buffers available */
+	struct list_head	list;
+
+	void *buffer; /* buffer pointer */
+	unsigned long buffer_size; /* size of allocated buffer */
+};
+
+/* */
+struct mmal_colourfx {
+	s32 enable;
+	u32 u;
+	u32 v;
+};

drivers/staging/media/platform/bcm2835/mmal-encodings.h

+/*
+ * Broadcom BM2835 V4L2 driver
+ *
+ * Copyright © 2013 Raspberry Pi (Trading) Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * Authors: Vincent Sanders <vincent.sanders@collabora.co.uk>
+ *          Dave Stevenson <dsteve@broadcom.com>
+ *          Simon Mellor <simellor@broadcom.com>
+ *          Luke Diamand <luked@broadcom.com>
+ */
+#ifndef MMAL_ENCODINGS_H
+#define MMAL_ENCODINGS_H
+
+#define MMAL_ENCODING_H264             MMAL_FOURCC('H', '2', '6', '4')
+#define MMAL_ENCODING_H263             MMAL_FOURCC('H', '2', '6', '3')
+#define MMAL_ENCODING_MP4V             MMAL_FOURCC('M', 'P', '4', 'V')
+#define MMAL_ENCODING_MP2V             MMAL_FOURCC('M', 'P', '2', 'V')
+#define MMAL_ENCODING_MP1V             MMAL_FOURCC('M', 'P', '1', 'V')
+#define MMAL_ENCODING_WMV3             MMAL_FOURCC('W', 'M', 'V', '3')
+#define MMAL_ENCODING_WMV2             MMAL_FOURCC('W', 'M', 'V', '2')
+#define MMAL_ENCODING_WMV1             MMAL_FOURCC('W', 'M', 'V', '1')
+#define MMAL_ENCODING_WVC1             MMAL_FOURCC('W', 'V', 'C', '1')
+#define MMAL_ENCODING_VP8              MMAL_FOURCC('V', 'P', '8', ' ')
+#define MMAL_ENCODING_VP7              MMAL_FOURCC('V', 'P', '7', ' ')
+#define MMAL_ENCODING_VP6              MMAL_FOURCC('V', 'P', '6', ' ')
+#define MMAL_ENCODING_THEORA           MMAL_FOURCC('T', 'H', 'E', 'O')
+#define MMAL_ENCODING_SPARK            MMAL_FOURCC('S', 'P', 'R', 'K')
+#define MMAL_ENCODING_MJPEG            MMAL_FOURCC('M', 'J', 'P', 'G')
+
+#define MMAL_ENCODING_JPEG             MMAL_FOURCC('J', 'P', 'E', 'G')
+#define MMAL_ENCODING_GIF              MMAL_FOURCC('G', 'I', 'F', ' ')
+#define MMAL_ENCODING_PNG              MMAL_FOURCC('P', 'N', 'G', ' ')
+#define MMAL_ENCODING_PPM              MMAL_FOURCC('P', 'P', 'M', ' ')
+#define MMAL_ENCODING_TGA              MMAL_FOURCC('T', 'G', 'A', ' ')
+#define MMAL_ENCODING_BMP              MMAL_FOURCC('B', 'M', 'P', ' ')
+
+#define MMAL_ENCODING_I420             MMAL_FOURCC('I', '4', '2', '0')
+#define MMAL_ENCODING_I420_SLICE       MMAL_FOURCC('S', '4', '2', '0')
+#define MMAL_ENCODING_YV12             MMAL_FOURCC('Y', 'V', '1', '2')
+#define MMAL_ENCODING_I422             MMAL_FOURCC('I', '4', '2', '2')
+#define MMAL_ENCODING_I422_SLICE       MMAL_FOURCC('S', '4', '2', '2')
+#define MMAL_ENCODING_YUYV             MMAL_FOURCC('Y', 'U', 'Y', 'V')
+#define MMAL_ENCODING_YVYU             MMAL_FOURCC('Y', 'V', 'Y', 'U')
+#define MMAL_ENCODING_UYVY             MMAL_FOURCC('U', 'Y', 'V', 'Y')
+#define MMAL_ENCODING_VYUY             MMAL_FOURCC('V', 'Y', 'U', 'Y')
+#define MMAL_ENCODING_NV12             MMAL_FOURCC('N', 'V', '1', '2')
+#define MMAL_ENCODING_NV21             MMAL_FOURCC('N', 'V', '2', '1')
+#define MMAL_ENCODING_ARGB             MMAL_FOURCC('A', 'R', 'G', 'B')
+#define MMAL_ENCODING_RGBA             MMAL_FOURCC('R', 'G', 'B', 'A')
+#define MMAL_ENCODING_ABGR             MMAL_FOURCC('A', 'B', 'G', 'R')
+#define MMAL_ENCODING_BGRA             MMAL_FOURCC('B', 'G', 'R', 'A')
+#define MMAL_ENCODING_RGB16            MMAL_FOURCC('R', 'G', 'B', '2')
+#define MMAL_ENCODING_RGB24            MMAL_FOURCC('R', 'G', 'B', '3')
+#define MMAL_ENCODING_RGB32            MMAL_FOURCC('R', 'G', 'B', '4')
+#define MMAL_ENCODING_BGR16            MMAL_FOURCC('B', 'G', 'R', '2')
+#define MMAL_ENCODING_BGR24            MMAL_FOURCC('B', 'G', 'R', '3')
+#define MMAL_ENCODING_BGR32            MMAL_FOURCC('B', 'G', 'R', '4')
+
+/** SAND Video (YUVUV128) format, native format understood by VideoCore.
+ * This format is *not* opaque - if requested you will receive full frames
+ * of YUV_UV video.
+ */
+#define MMAL_ENCODING_YUVUV128         MMAL_FOURCC('S', 'A', 'N', 'D')
+
+/** VideoCore opaque image format, image handles are returned to
+ * the host but not the actual image data.
+ */
+#define MMAL_ENCODING_OPAQUE           MMAL_FOURCC('O', 'P', 'Q', 'V')
+
+/** An EGL image handle
+ */
+#define MMAL_ENCODING_EGL_IMAGE        MMAL_FOURCC('E', 'G', 'L', 'I')
+
+/* }@ */
+
+/** \name Pre-defined audio encodings */
+/* @{ */
+#define MMAL_ENCODING_PCM_UNSIGNED_BE  MMAL_FOURCC('P', 'C', 'M', 'U')
+#define MMAL_ENCODING_PCM_UNSIGNED_LE  MMAL_FOURCC('p', 'c', 'm', 'u')
+#define MMAL_ENCODING_PCM_SIGNED_BE    MMAL_FOURCC('P', 'C', 'M', 'S')
+#define MMAL_ENCODING_PCM_SIGNED_LE    MMAL_FOURCC('p', 'c', 'm', 's')
+#define MMAL_ENCODING_PCM_FLOAT_BE     MMAL_FOURCC('P', 'C', 'M', 'F')
+#define MMAL_ENCODING_PCM_FLOAT_LE     MMAL_FOURCC('p', 'c', 'm', 'f')
+
+/* Pre-defined H264 encoding variants */
+
+/** ISO 14496-10 Annex B byte stream format */
+#define MMAL_ENCODING_VARIANT_H264_DEFAULT   0
+/** ISO 14496-15 AVC stream format */
+#define MMAL_ENCODING_VARIANT_H264_AVC1      MMAL_FOURCC('A', 'V', 'C', '1')
+/** Implicitly delineated NAL units without emulation prevention */
+#define MMAL_ENCODING_VARIANT_H264_RAW       MMAL_FOURCC('R', 'A', 'W', ' ')
+
+
+/** \defgroup MmalColorSpace List of pre-defined video color spaces
+ * This defines a list of common color spaces. This list isn't exhaustive and
+ * is only provided as a convenience to avoid clients having to use FourCC
+ * codes directly. However components are allowed to define and use their own
+ * FourCC codes.
+ */
+/* @{ */
+
+/** Unknown color space */
+#define MMAL_COLOR_SPACE_UNKNOWN       0
+/** ITU-R BT.601-5 [SDTV] */
+#define MMAL_COLOR_SPACE_ITUR_BT601    MMAL_FOURCC('Y', '6', '0', '1')
+/** ITU-R BT.709-3 [HDTV] */
+#define MMAL_COLOR_SPACE_ITUR_BT709    MMAL_FOURCC('Y', '7', '0', '9')
+/** JPEG JFIF */
+#define MMAL_COLOR_SPACE_JPEG_JFIF     MMAL_FOURCC('Y', 'J', 'F', 'I')
+/** Title 47 Code of Federal Regulations (2003) 73.682 (a) (20) */
+#define MMAL_COLOR_SPACE_FCC           MMAL_FOURCC('Y', 'F', 'C', 'C')
+/** Society of Motion Picture and Television Engineers 240M (1999) */
+#define MMAL_COLOR_SPACE_SMPTE240M     MMAL_FOURCC('Y', '2', '4', '0')
+/** ITU-R BT.470-2 System M */
+#define MMAL_COLOR_SPACE_BT470_2_M     MMAL_FOURCC('Y', '_', '_', 'M')
+/** ITU-R BT.470-2 System BG */
+#define MMAL_COLOR_SPACE_BT470_2_BG    MMAL_FOURCC('Y', '_', 'B', 'G')
+/** JPEG JFIF, but with 16..255 luma */
+#define MMAL_COLOR_SPACE_JFIF_Y16_255  MMAL_FOURCC('Y', 'Y', '1', '6')
+/* @} MmalColorSpace List */
+
+#endif /* MMAL_ENCODINGS_H */

drivers/staging/media/platform/bcm2835/mmal-msg-common.h

+/*
+ * Broadcom BM2835 V4L2 driver
+ *
+ * Copyright © 2013 Raspberry Pi (Trading) Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * Authors: Vincent Sanders <vincent.sanders@collabora.co.uk>
+ *          Dave Stevenson <dsteve@broadcom.com>
+ *          Simon Mellor <simellor@broadcom.com>
+ *          Luke Diamand <luked@broadcom.com>
+ */
+
+#ifndef MMAL_MSG_COMMON_H
+#define MMAL_MSG_COMMON_H
+
+enum mmal_msg_status {
+	MMAL_MSG_STATUS_SUCCESS = 0, /**< Success */
+	MMAL_MSG_STATUS_ENOMEM,      /**< Out of memory */
+	MMAL_MSG_STATUS_ENOSPC,      /**< Out of resources other than memory */
+	MMAL_MSG_STATUS_EINVAL,      /**< Argument is invalid */
+	MMAL_MSG_STATUS_ENOSYS,      /**< Function not implemented */
+	MMAL_MSG_STATUS_ENOENT,      /**< No such file or directory */
+	MMAL_MSG_STATUS_ENXIO,       /**< No such device or address */
+	MMAL_MSG_STATUS_EIO,         /**< I/O error */
+	MMAL_MSG_STATUS_ESPIPE,      /**< Illegal seek */
+	MMAL_MSG_STATUS_ECORRUPT,    /**< Data is corrupt \attention */
+	MMAL_MSG_STATUS_ENOTREADY,   /**< Component is not ready */
+	MMAL_MSG_STATUS_ECONFIG,     /**< Component is not configured */
+	MMAL_MSG_STATUS_EISCONN,     /**< Port is already connected */
+	MMAL_MSG_STATUS_ENOTCONN,    /**< Port is disconnected */
+	MMAL_MSG_STATUS_EAGAIN,      /**< Resource temporarily unavailable. */
+	MMAL_MSG_STATUS_EFAULT,      /**< Bad address */
+};
+
+struct mmal_rect {
+	s32 x;      /**< x coordinate (from left) */
+	s32 y;      /**< y coordinate (from top) */
+	s32 width;  /**< width */
+	s32 height; /**< height */
+};
+
+struct mmal_rational {
+	s32 num;    /**< Numerator */
+	s32 den;    /**< Denominator */
+};
+
+#endif /* MMAL_MSG_COMMON_H */

drivers/staging/media/platform/bcm2835/mmal-msg-format.h

+/*
+ * Broadcom BM2835 V4L2 driver
+ *
+ * Copyright © 2013 Raspberry Pi (Trading) Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * Authors: Vincent Sanders <vincent.sanders@collabora.co.uk>
+ *          Dave Stevenson <dsteve@broadcom.com>
+ *          Simon Mellor <simellor@broadcom.com>
+ *          Luke Diamand <luked@broadcom.com>
+ */
+
+#ifndef MMAL_MSG_FORMAT_H
+#define MMAL_MSG_FORMAT_H
+
+#include "mmal-msg-common.h"
+
+/* MMAL_ES_FORMAT_T */
+
+
+struct mmal_audio_format {
+	u32 channels;           /**< Number of audio channels */
+	u32 sample_rate;        /**< Sample rate */
+
+	u32 bits_per_sample;    /**< Bits per sample */
+	u32 block_align;        /**< Size of a block of data */
+};
+
+struct mmal_video_format {
+	u32 width;        /**< Width of frame in pixels */
+	u32 height;       /**< Height of frame in rows of pixels */
+	struct mmal_rect crop;         /**< Visible region of the frame */
+	struct mmal_rational frame_rate;   /**< Frame rate */
+	struct mmal_rational par;          /**< Pixel aspect ratio */
+
+	/* FourCC specifying the color space of the video stream. See the
+	 * \ref MmalColorSpace "pre-defined color spaces" for some examples.
+	 */
+	u32 color_space;
+};
+
+struct mmal_subpicture_format {
+	u32 x_offset;
+	u32 y_offset;
+};
+
+union mmal_es_specific_format {
+	struct mmal_audio_format audio;
+	struct mmal_video_format video;
+	struct mmal_subpicture_format subpicture;
+};
+
+/** Definition of an elementary stream format (MMAL_ES_FORMAT_T) */
+struct mmal_es_format {
+	u32 type;      /* enum mmal_es_type */
+
+	u32 encoding;  /* FourCC specifying encoding of the elementary stream.*/
+	u32 encoding_variant; /* FourCC specifying the specific
+			       * encoding variant of the elementary
+			       * stream.
+			       */
+
+	union mmal_es_specific_format *es; /* TODO: pointers in
+					    * message serialisation?!?
+					    */
+					    /* Type specific
+					     * information for the
+					     * elementary stream
+					     */
+
+	u32 bitrate;        /**< Bitrate in bits per second */
+	u32 flags; /**< Flags describing properties of the elementary stream. */
+
+	u32 extradata_size;       /**< Size of the codec specific data */
+	u8  *extradata;           /**< Codec specific data */
+};
+
+#endif /* MMAL_MSG_FORMAT_H */

drivers/staging/media/platform/bcm2835/mmal-msg-port.h

+/*
+ * Broadcom BM2835 V4L2 driver
+ *
+ * Copyright © 2013 Raspberry Pi (Trading) Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * Authors: Vincent Sanders <vincent.sanders@collabora.co.uk>
+ *          Dave Stevenson <dsteve@broadcom.com>
+ *          Simon Mellor <simellor@broadcom.com>
+ *          Luke Diamand <luked@broadcom.com>
+ */
+
+/* MMAL_PORT_TYPE_T */
+enum mmal_port_type {
+	MMAL_PORT_TYPE_UNKNOWN = 0,  /**< Unknown port type */
+	MMAL_PORT_TYPE_CONTROL,      /**< Control port */
+	MMAL_PORT_TYPE_INPUT,        /**< Input port */
+	MMAL_PORT_TYPE_OUTPUT,       /**< Output port */
+	MMAL_PORT_TYPE_CLOCK,        /**< Clock port */
+};
+
+/** The port is pass-through and doesn't need buffer headers allocated */
+#define MMAL_PORT_CAPABILITY_PASSTHROUGH                       0x01
+/** The port wants to allocate the buffer payloads.
+ * This signals a preference that payload allocation should be done
+ * on this port for efficiency reasons. */
+#define MMAL_PORT_CAPABILITY_ALLOCATION                        0x02
+/** The port supports format change events.
+ * This applies to input ports and is used to let the client know
+ * whether the port supports being reconfigured via a format
+ * change event (i.e. without having to disable the port). */
+#define MMAL_PORT_CAPABILITY_SUPPORTS_EVENT_FORMAT_CHANGE      0x04
+
+/* mmal port structure (MMAL_PORT_T)
+ *
+ * most elements are informational only, the pointer values for
+ * interogation messages are generally provided as additional
+ * strucures within the message. When used to set values only teh
+ * buffer_num, buffer_size and userdata parameters are writable.
+ */
+struct mmal_port {
+	void *priv; /* Private member used by the framework */
+	const char *name; /* Port name. Used for debugging purposes (RO) */
+
+	u32 type;      /* Type of the port (RO) enum mmal_port_type */
+	u16 index;     /* Index of the port in its type list (RO) */
+	u16 index_all; /* Index of the port in the list of all ports (RO) */
+
+	u32 is_enabled; /* Indicates whether the port is enabled or not (RO) */
+	struct mmal_es_format *format; /* Format of the elementary stream */
+
+	u32 buffer_num_min; /* Minimum number of buffers the port
+			     *   requires (RO).  This is set by the
+			     *   component.
+			     */
+
+	u32 buffer_size_min; /* Minimum size of buffers the port
+			      * requires (RO).  This is set by the
+			      * component.
+			      */
+
+	u32 buffer_alignment_min; /* Minimum alignment requirement for
+				   * the buffers (RO).  A value of
+				   * zero means no special alignment
+				   * requirements.  This is set by the
+				   * component.
+				   */
+
+	u32 buffer_num_recommended;  /* Number of buffers the port
+				      * recommends for optimal
+				      * performance (RO).  A value of
+				      * zero means no special
+				      * recommendation.  This is set
+				      * by the component.
+				      */
+
+	u32 buffer_size_recommended; /* Size of buffers the port
+				      * recommends for optimal
+				      * performance (RO).  A value of
+				      * zero means no special
+				      * recommendation.  This is set
+				      * by the component.
+				      */
+
+	u32 buffer_num; /* Actual number of buffers the port will use.
+			 * This is set by the client.
+			 */
+
+	u32 buffer_size; /* Actual maximum size of the buffers that
+			  * will be sent to the port. This is set by
+			  * the client.
+			  */
+
+	void *component; /* Component this port belongs to (Read Only) */
+
+	void *userdata; /* Field reserved for use by the client */
+
+	u32 capabilities; /* Flags describing the capabilities of a
+			   * port (RO).  Bitwise combination of \ref
+			   * portcapabilities "Port capabilities"
+			   * values.
+			   */
+
+};

drivers/staging/media/platform/bcm2835/mmal-vchiq.h

+/*
+ * Broadcom BM2835 V4L2 driver
+ *
+ * Copyright © 2013 Raspberry Pi (Trading) Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * Authors: Vincent Sanders <vincent.sanders@collabora.co.uk>
+ *          Dave Stevenson <dsteve@broadcom.com>
+ *          Simon Mellor <simellor@broadcom.com>
+ *          Luke Diamand <luked@broadcom.com>
+ *
+ * MMAL interface to VCHIQ message passing
+ */
+
+#ifndef MMAL_VCHIQ_H
+#define MMAL_VCHIQ_H
+
+#include "mmal-msg-format.h"
+
+#define MAX_PORT_COUNT 4
+
+/* Maximum size of the format extradata. */
+#define MMAL_FORMAT_EXTRADATA_MAX_SIZE 128
+
+struct vchiq_mmal_instance;
+
+enum vchiq_mmal_es_type {
+	MMAL_ES_TYPE_UNKNOWN,     /**< Unknown elementary stream type */
+	MMAL_ES_TYPE_CONTROL,     /**< Elementary stream of control commands */
+	MMAL_ES_TYPE_AUDIO,       /**< Audio elementary stream */
+	MMAL_ES_TYPE_VIDEO,       /**< Video elementary stream */
+	MMAL_ES_TYPE_SUBPICTURE   /**< Sub-picture elementary stream */
+};
+
+/* rectangle, used lots so it gets its own struct */
+struct vchiq_mmal_rect {
+	s32 x;
+	s32 y;
+	s32 width;
+	s32 height;
+};
+
+struct vchiq_mmal_port_buffer {
+	unsigned int num; /* number of buffers */
+	u32 size; /* size of buffers */
+	u32 alignment; /* alignment of buffers */
+};
+
+struct vchiq_mmal_port;
+
+typedef void (*vchiq_mmal_buffer_cb)(
+		struct vchiq_mmal_instance  *instance,
+		struct vchiq_mmal_port *port,
+		int status, struct mmal_buffer *buffer,
+		unsigned long length, u32 mmal_flags, s64 dts, s64 pts);
+
+struct vchiq_mmal_port {
+	bool enabled;
+	u32 handle;
+	u32 type; /* port type, cached to use on port info set */
+	u32 index; /* port index, cached to use on port info set */
+
+	/* component port belongs to, allows simple deref */
+	struct vchiq_mmal_component *component;
+
+	struct vchiq_mmal_port *connected; /* port conencted to */
+
+	/* buffer info */
+	struct vchiq_mmal_port_buffer minimum_buffer;
+	struct vchiq_mmal_port_buffer recommended_buffer;
+	struct vchiq_mmal_port_buffer current_buffer;
+
+	/* stream format */
+	struct mmal_es_format format;
+	/* elementry stream format */
+	union mmal_es_specific_format es;
+
+	/* data buffers to fill */
+	struct list_head buffers;
+	/* lock to serialise adding and removing buffers from list */
+	spinlock_t slock;
+	/* count of how many buffer header refils have failed because
+	 * there was no buffer to satisfy them
+	 */
+	int buffer_underflow;
+	/* callback on buffer completion */
+	vchiq_mmal_buffer_cb buffer_cb;
+	/* callback context */
+	void *cb_ctx;
+};
+
+struct vchiq_mmal_component {
+	bool enabled;
+	u32 handle;  /* VideoCore handle for component */
+	u32 inputs;  /* Number of input ports */
+	u32 outputs; /* Number of output ports */
+	u32 clocks;  /* Number of clock ports */
+	struct vchiq_mmal_port control; /* control port */
+	struct vchiq_mmal_port input[MAX_PORT_COUNT]; /* input ports */
+	struct vchiq_mmal_port output[MAX_PORT_COUNT]; /* output ports */
+	struct vchiq_mmal_port clock[MAX_PORT_COUNT]; /* clock ports */
+};
+
+
+int vchiq_mmal_init(struct vchiq_mmal_instance **out_instance);
+int vchiq_mmal_finalise(struct vchiq_mmal_instance *instance);
+
+/* Initialise a mmal component and its ports
+*
+*/
+int vchiq_mmal_component_init(
+		struct vchiq_mmal_instance *instance,
+		const char *name,
+		struct vchiq_mmal_component **component_out);
+
+int vchiq_mmal_component_finalise(
+		struct vchiq_mmal_instance *instance,
+		struct vchiq_mmal_component *component);
+
+int vchiq_mmal_component_enable(
+		struct vchiq_mmal_instance *instance,
+		struct vchiq_mmal_component *component);
+
+int vchiq_mmal_component_disable(
+		struct vchiq_mmal_instance *instance,
+		struct vchiq_mmal_component *component);
+
+
+
+/* enable a mmal port
+ *
+ * enables a port and if a buffer callback provided enque buffer
+ * headers as apropriate for the port.
+ */
+int vchiq_mmal_port_enable(
+		struct vchiq_mmal_instance *instance,
+		struct vchiq_mmal_port *port,
+		vchiq_mmal_buffer_cb buffer_cb);
+
+/* disable a port
+ *
+ * disable a port will dequeue any pending buffers
+ */
+int vchiq_mmal_port_disable(struct vchiq_mmal_instance *instance,
+			   struct vchiq_mmal_port *port);
+
+
+int vchiq_mmal_port_parameter_set(struct vchiq_mmal_instance *instance,
+				  struct vchiq_mmal_port *port,
+				  u32 parameter,
+				  void *value,
+				  u32 value_size);
+
+int vchiq_mmal_port_parameter_get(struct vchiq_mmal_instance *instance,
+				  struct vchiq_mmal_port *port,
+				  u32 parameter,
+				  void *value,
+				  u32 *value_size);
+
+int vchiq_mmal_port_set_format(struct vchiq_mmal_instance *instance,
+			       struct vchiq_mmal_port *port);
+
+int vchiq_mmal_port_connect_tunnel(struct vchiq_mmal_instance *instance,
+			    struct vchiq_mmal_port *src,
+			    struct vchiq_mmal_port *dst);
+
+int vchiq_mmal_version(struct vchiq_mmal_instance *instance,
+		       u32 *major_out,
+		       u32 *minor_out);
+
+int vchiq_mmal_submit_buffer(struct vchiq_mmal_instance *instance,
+			     struct vchiq_mmal_port *port,
+			     struct mmal_buffer *buf);
+
+#endif /* MMAL_VCHIQ_H */