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 <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: anholt

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

@@ -0,0 +1,145 @@
+/*
+ * 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 <[email protected]>
+ *          Dave Stevenson <[email protected]>
+ *          Simon Mellor <[email protected]>
+ *          Luke Diamand <[email protected]>
+ *
+ * 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); \
+}