/*
 * 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>
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <media/videobuf2-vmalloc.h>
#include <media/videobuf2-dma-contig.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
#include <media/v4l2-common.h>
#include <linux/delay.h>

#include "mmal-common.h"
#include "mmal-encodings.h"
#include "mmal-vchiq.h"
#include "mmal-msg.h"
#include "mmal-parameters.h"
#include "bcm2835-camera.h"

#define BM2835_MMAL_VERSION "0.0.2"
#define BM2835_MMAL_MODULE_NAME "bcm2835-v4l2"
#define MIN_WIDTH 32
#define MIN_HEIGHT 32
#define MIN_BUFFER_SIZE (80 * 1024)

#define MAX_VIDEO_MODE_WIDTH 1280
#define MAX_VIDEO_MODE_HEIGHT 720

#define MAX_BCM2835_CAMERAS 2

MODULE_DESCRIPTION("Broadcom 2835 MMAL video capture");
MODULE_AUTHOR("Vincent Sanders");
MODULE_LICENSE("GPL");
MODULE_VERSION(BM2835_MMAL_VERSION);

int bcm2835_v4l2_debug;
module_param_named(debug, bcm2835_v4l2_debug, int, 0644);
MODULE_PARM_DESC(bcm2835_v4l2_debug, "Debug level 0-2");

#define UNSET (-1)
static int video_nr[] = {[0 ... (MAX_BCM2835_CAMERAS - 1)] = UNSET };
module_param_array(video_nr, int, NULL, 0644);
MODULE_PARM_DESC(video_nr, "videoX start numbers, -1 is autodetect");

static int max_video_width = MAX_VIDEO_MODE_WIDTH;
static int max_video_height = MAX_VIDEO_MODE_HEIGHT;
module_param(max_video_width, int, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
MODULE_PARM_DESC(max_video_width, "Threshold for video mode");
module_param(max_video_height, int, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
MODULE_PARM_DESC(max_video_height, "Threshold for video mode");

/* Gstreamer bug https://bugzilla.gnome.org/show_bug.cgi?id=726521
 * v4l2src does bad (and actually wrong) things when the vidioc_enum_framesizes
 * function says type V4L2_FRMSIZE_TYPE_STEPWISE, which we do by default.
 * It's happier if we just don't say anything at all, when it then
 * sets up a load of defaults that it thinks might work.
 * If gst_v4l2src_is_broken is non-zero, then we remove the function from
 * our function table list (actually switch to an alternate set, but same
 * result).
 */
static int gst_v4l2src_is_broken;
module_param(gst_v4l2src_is_broken, int, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
MODULE_PARM_DESC(gst_v4l2src_is_broken, "If non-zero, enable workaround for Gstreamer");

/* global device data array */
static struct bm2835_mmal_dev *gdev[MAX_BCM2835_CAMERAS];

#define FPS_MIN 1
#define FPS_MAX 90

/* timeperframe: min/max and default */
static const struct v4l2_fract
	tpf_min     = {.numerator = 1,		.denominator = FPS_MAX},
	tpf_max     = {.numerator = 1,	        .denominator = FPS_MIN},
	tpf_default = {.numerator = 1000,	.denominator = 30000};

/* video formats */
static struct mmal_fmt formats[] = {
	{
	 .name = "4:2:0, planar, YUV",
	 .fourcc = V4L2_PIX_FMT_YUV420,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_I420,
	 .depth = 12,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 1,
	 },
	{
	 .name = "4:2:2, packed, YUYV",
	 .fourcc = V4L2_PIX_FMT_YUYV,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_YUYV,
	 .depth = 16,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 2,
	 },
	{
	 .name = "RGB24 (LE)",
	 .fourcc = V4L2_PIX_FMT_RGB24,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_RGB24,
	 .depth = 24,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 3,
	 },
	{
	 .name = "JPEG",
	 .fourcc = V4L2_PIX_FMT_JPEG,
	 .flags = V4L2_FMT_FLAG_COMPRESSED,
	 .mmal = MMAL_ENCODING_JPEG,
	 .depth = 8,
	 .mmal_component = MMAL_COMPONENT_IMAGE_ENCODE,
	 .ybbp = 0,
	 },
	{
	 .name = "H264",
	 .fourcc = V4L2_PIX_FMT_H264,
	 .flags = V4L2_FMT_FLAG_COMPRESSED,
	 .mmal = MMAL_ENCODING_H264,
	 .depth = 8,
	 .mmal_component = MMAL_COMPONENT_VIDEO_ENCODE,
	 .ybbp = 0,
	 },
	{
	 .name = "MJPEG",
	 .fourcc = V4L2_PIX_FMT_MJPEG,
	 .flags = V4L2_FMT_FLAG_COMPRESSED,
	 .mmal = MMAL_ENCODING_MJPEG,
	 .depth = 8,
	 .mmal_component = MMAL_COMPONENT_VIDEO_ENCODE,
	 .ybbp = 0,
	 },
	{
	 .name = "4:2:2, packed, YVYU",
	 .fourcc = V4L2_PIX_FMT_YVYU,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_YVYU,
	 .depth = 16,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 2,
	 },
	{
	 .name = "4:2:2, packed, VYUY",
	 .fourcc = V4L2_PIX_FMT_VYUY,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_VYUY,
	 .depth = 16,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 2,
	 },
	{
	 .name = "4:2:2, packed, UYVY",
	 .fourcc = V4L2_PIX_FMT_UYVY,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_UYVY,
	 .depth = 16,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 2,
	 },
	{
	 .name = "4:2:0, planar, NV12",
	 .fourcc = V4L2_PIX_FMT_NV12,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_NV12,
	 .depth = 12,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 1,
	 },
	{
	 .name = "RGB24 (BE)",
	 .fourcc = V4L2_PIX_FMT_BGR24,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_BGR24,
	 .depth = 24,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 3,
	 },
	{
	 .name = "4:2:0, planar, YVU",
	 .fourcc = V4L2_PIX_FMT_YVU420,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_YV12,
	 .depth = 12,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 1,
	 },
	{
	 .name = "4:2:0, planar, NV21",
	 .fourcc = V4L2_PIX_FMT_NV21,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_NV21,
	 .depth = 12,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 1,
	 },
	{
	 .name = "RGB32 (BE)",
	 .fourcc = V4L2_PIX_FMT_BGR32,
	 .flags = 0,
	 .mmal = MMAL_ENCODING_BGRA,
	 .depth = 32,
	 .mmal_component = MMAL_COMPONENT_CAMERA,
	 .ybbp = 4,
	 },
};

static struct mmal_fmt *get_format(struct v4l2_format *f)
{
	struct mmal_fmt *fmt;
	unsigned int k;

	for (k = 0; k < ARRAY_SIZE(formats); k++) {
		fmt = &formats[k];
		if (fmt->fourcc == f->fmt.pix.pixelformat)
			break;
	}

	if (k == ARRAY_SIZE(formats))
		return NULL;

	return &formats[k];
}

/* ------------------------------------------------------------------
	Videobuf queue operations
   ------------------------------------------------------------------*/

static int queue_setup(struct vb2_queue *vq,
		       unsigned int *nbuffers, unsigned int *nplanes,
		       unsigned int sizes[], struct device *alloc_ctxs[])
{
	struct bm2835_mmal_dev *dev = vb2_get_drv_priv(vq);
	unsigned long size;

	/* refuse queue setup if port is not configured */
	if (dev->capture.port == NULL) {
		v4l2_err(&dev->v4l2_dev,
			 "%s: capture port not configured\n", __func__);
		return -EINVAL;
	}

	size = dev->capture.port->current_buffer.size;
	if (size == 0) {
		v4l2_err(&dev->v4l2_dev,
			 "%s: capture port buffer size is zero\n", __func__);
		return -EINVAL;
	}

	if (*nbuffers < (dev->capture.port->current_buffer.num + 2))
		*nbuffers = (dev->capture.port->current_buffer.num + 2);

	*nplanes = 1;

	sizes[0] = size;

	/*
	 * videobuf2-vmalloc allocator is context-less so no need to set
	 * alloc_ctxs array.
	 */

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev, "%s: dev:%p\n",
		 __func__, dev);

	return 0;
}

static int buffer_prepare(struct vb2_buffer *vb)
{
	struct bm2835_mmal_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
	unsigned long size;

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev, "%s: dev:%p\n",
		 __func__, dev);

	BUG_ON(dev->capture.port == NULL);
	BUG_ON(dev->capture.fmt == NULL);

	size = dev->capture.stride * dev->capture.height;
	if (vb2_plane_size(vb, 0) < size) {
		v4l2_err(&dev->v4l2_dev,
			 "%s data will not fit into plane (%lu < %lu)\n",
			 __func__, vb2_plane_size(vb, 0), size);
		return -EINVAL;
	}

	return 0;
}

static inline bool is_capturing(struct bm2835_mmal_dev *dev)
{
	return dev->capture.camera_port ==
	    &dev->
	    component[MMAL_COMPONENT_CAMERA]->output[MMAL_CAMERA_PORT_CAPTURE];
}

static void buffer_cb(struct vchiq_mmal_instance *instance,
		      struct vchiq_mmal_port *port,
		      int status,
		      struct mmal_buffer *buf,
		      unsigned long length, u32 mmal_flags, s64 dts, s64 pts)
{
	struct bm2835_mmal_dev *dev = port->cb_ctx;

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
		 "%s: status:%d, buf:%p, length:%lu, flags %u, pts %lld\n",
		 __func__, status, buf, length, mmal_flags, pts);

	if (status != 0) {
		/* error in transfer */
		if (buf != NULL) {
			/* there was a buffer with the error so return it */
			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
		}
		return;
	} else if (length == 0) {
		/* stream ended */
		if (buf != NULL) {
			/* this should only ever happen if the port is
			 * disabled and there are buffers still queued
			 */
			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
			pr_debug("Empty buffer");
		} else if (dev->capture.frame_count) {
			/* grab another frame */
			if (is_capturing(dev)) {
				pr_debug("Grab another frame");
				vchiq_mmal_port_parameter_set(
					instance,
					dev->capture.
					camera_port,
					MMAL_PARAMETER_CAPTURE,
					&dev->capture.
					frame_count,
					sizeof(dev->capture.frame_count));
			}
		} else {
			/* signal frame completion */
			complete(&dev->capture.frame_cmplt);
		}
	} else {
		if (dev->capture.frame_count) {
			if (dev->capture.vc_start_timestamp != -1 &&
			    pts != 0) {
				struct timeval timestamp;
				s64 runtime_us = pts -
				    dev->capture.vc_start_timestamp;
				u32 div = 0;
				u32 rem = 0;

				div =
				    div_u64_rem(runtime_us, USEC_PER_SEC, &rem);
				timestamp.tv_sec =
				    dev->capture.kernel_start_ts.tv_sec + div;
				timestamp.tv_usec =
				    dev->capture.kernel_start_ts.tv_usec + rem;

				if (timestamp.tv_usec >=
				    USEC_PER_SEC) {
					timestamp.tv_sec++;
					timestamp.tv_usec -=
					    USEC_PER_SEC;
				}
				v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
					 "Convert start time %d.%06d and %llu "
					 "with offset %llu to %d.%06d\n",
					 (int)dev->capture.kernel_start_ts.
					 tv_sec,
					 (int)dev->capture.kernel_start_ts.
					 tv_usec,
					 dev->capture.vc_start_timestamp, pts,
					 (int)timestamp.tv_sec,
					 (int)timestamp.tv_usec);
				buf->vb.vb2_buf.timestamp = timestamp.tv_sec * 1000000000ULL +
					timestamp.tv_usec * 1000ULL;
			} else {
				buf->vb.vb2_buf.timestamp = ktime_get_ns();
			}

			vb2_set_plane_payload(&buf->vb.vb2_buf, 0, length);
			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);

			if (mmal_flags & MMAL_BUFFER_HEADER_FLAG_EOS &&
			    is_capturing(dev)) {
				v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
					 "Grab another frame as buffer has EOS");
				vchiq_mmal_port_parameter_set(
					instance,
					dev->capture.
					camera_port,
					MMAL_PARAMETER_CAPTURE,
					&dev->capture.
					frame_count,
					sizeof(dev->capture.frame_count));
			}
		} else {
			/* signal frame completion */
			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
			complete(&dev->capture.frame_cmplt);
		}
	}
}

static int enable_camera(struct bm2835_mmal_dev *dev)
{
	int ret;

	if (!dev->camera_use_count) {
		ret = vchiq_mmal_port_parameter_set(
			dev->instance,
			&dev->component[MMAL_COMPONENT_CAMERA]->control,
			MMAL_PARAMETER_CAMERA_NUM, &dev->camera_num,
			sizeof(dev->camera_num));
		if (ret < 0) {
			v4l2_err(&dev->v4l2_dev,
				 "Failed setting camera num, ret %d\n", ret);
			return -EINVAL;
		}

		ret = vchiq_mmal_component_enable(
				dev->instance,
				dev->component[MMAL_COMPONENT_CAMERA]);
		if (ret < 0) {
			v4l2_err(&dev->v4l2_dev,
				 "Failed enabling camera, ret %d\n", ret);
			return -EINVAL;
		}
	}
	dev->camera_use_count++;
	v4l2_dbg(1, bcm2835_v4l2_debug,
		 &dev->v4l2_dev, "enabled camera (refcount %d)\n",
			dev->camera_use_count);
	return 0;
}

static int disable_camera(struct bm2835_mmal_dev *dev)
{
	int ret;

	if (!dev->camera_use_count) {
		v4l2_err(&dev->v4l2_dev,
			 "Disabled the camera when already disabled\n");
		return -EINVAL;
	}
	dev->camera_use_count--;
	if (!dev->camera_use_count) {
		unsigned int i = 0xFFFFFFFF;

		v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
			 "Disabling camera\n");
		ret =
		    vchiq_mmal_component_disable(
				dev->instance,
				dev->component[MMAL_COMPONENT_CAMERA]);
		if (ret < 0) {
			v4l2_err(&dev->v4l2_dev,
				 "Failed disabling camera, ret %d\n", ret);
			return -EINVAL;
		}
		vchiq_mmal_port_parameter_set(
			dev->instance,
			&dev->component[MMAL_COMPONENT_CAMERA]->control,
			MMAL_PARAMETER_CAMERA_NUM, &i,
			sizeof(i));
	}
	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
		 "Camera refcount now %d\n", dev->camera_use_count);
	return 0;
}

static void buffer_queue(struct vb2_buffer *vb)
{
	struct bm2835_mmal_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
	struct vb2_v4l2_buffer *vb2 = to_vb2_v4l2_buffer(vb);
	struct mmal_buffer *buf = container_of(vb2, struct mmal_buffer, vb);
	int ret;

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
		 "%s: dev:%p buf:%p\n", __func__, dev, buf);

	buf->buffer = vb2_plane_vaddr(&buf->vb.vb2_buf, 0);
	buf->buffer_size = vb2_plane_size(&buf->vb.vb2_buf, 0);

	ret = vchiq_mmal_submit_buffer(dev->instance, dev->capture.port, buf);
	if (ret < 0)
		v4l2_err(&dev->v4l2_dev, "%s: error submitting buffer\n",
			 __func__);
}

static int start_streaming(struct vb2_queue *vq, unsigned int count)
{
	struct bm2835_mmal_dev *dev = vb2_get_drv_priv(vq);
	int ret;
	int parameter_size;

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev, "%s: dev:%p\n",
		 __func__, dev);

	/* ensure a format has actually been set */
	if (dev->capture.port == NULL)
		return -EINVAL;

	if (enable_camera(dev) < 0) {
		v4l2_err(&dev->v4l2_dev, "Failed to enable camera\n");
		return -EINVAL;
	}

	/*init_completion(&dev->capture.frame_cmplt); */

	/* enable frame capture */
	dev->capture.frame_count = 1;

	/* if the preview is not already running, wait for a few frames for AGC
	 * to settle down.
	 */
	if (!dev->component[MMAL_COMPONENT_PREVIEW]->enabled)
		msleep(300);

	/* enable the connection from camera to encoder (if applicable) */
	if (dev->capture.camera_port != dev->capture.port
	    && dev->capture.camera_port) {
		ret = vchiq_mmal_port_enable(dev->instance,
					     dev->capture.camera_port, NULL);
		if (ret) {
			v4l2_err(&dev->v4l2_dev,
				 "Failed to enable encode tunnel - error %d\n",
				 ret);
			return -1;
		}
	}

	/* Get VC timestamp at this point in time */
	parameter_size = sizeof(dev->capture.vc_start_timestamp);
	if (vchiq_mmal_port_parameter_get(dev->instance,
					  dev->capture.camera_port,
					  MMAL_PARAMETER_SYSTEM_TIME,
					  &dev->capture.vc_start_timestamp,
					  &parameter_size)) {
		v4l2_err(&dev->v4l2_dev,
			 "Failed to get VC start time - update your VC f/w\n");

		/* Flag to indicate just to rely on kernel timestamps */
		dev->capture.vc_start_timestamp = -1;
	} else
		v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
			 "Start time %lld size %d\n",
			 dev->capture.vc_start_timestamp, parameter_size);

	v4l2_get_timestamp(&dev->capture.kernel_start_ts);

	/* enable the camera port */
	dev->capture.port->cb_ctx = dev;
	ret =
	    vchiq_mmal_port_enable(dev->instance, dev->capture.port, buffer_cb);
	if (ret) {
		v4l2_err(&dev->v4l2_dev,
			"Failed to enable capture port - error %d. "
			"Disabling camera port again\n", ret);

		vchiq_mmal_port_disable(dev->instance,
					dev->capture.camera_port);
		if (disable_camera(dev) < 0) {
			v4l2_err(&dev->v4l2_dev, "Failed to disable camera\n");
			return -EINVAL;
		}
		return -1;
	}

	/* capture the first frame */
	vchiq_mmal_port_parameter_set(dev->instance,
				      dev->capture.camera_port,
				      MMAL_PARAMETER_CAPTURE,
				      &dev->capture.frame_count,
				      sizeof(dev->capture.frame_count));
	return 0;
}

/* abort streaming and wait for last buffer */
static void stop_streaming(struct vb2_queue *vq)
{
	int ret;
	struct bm2835_mmal_dev *dev = vb2_get_drv_priv(vq);

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev, "%s: dev:%p\n",
		 __func__, dev);

	init_completion(&dev->capture.frame_cmplt);
	dev->capture.frame_count = 0;

	/* ensure a format has actually been set */
	if (dev->capture.port == NULL) {
		v4l2_err(&dev->v4l2_dev,
			 "no capture port - stream not started?\n");
		return;
	}

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev, "stopping capturing\n");

	/* stop capturing frames */
	vchiq_mmal_port_parameter_set(dev->instance,
				      dev->capture.camera_port,
				      MMAL_PARAMETER_CAPTURE,
				      &dev->capture.frame_count,
				      sizeof(dev->capture.frame_count));

	/* wait for last frame to complete */
	ret = wait_for_completion_timeout(&dev->capture.frame_cmplt, HZ);
	if (ret <= 0)
		v4l2_err(&dev->v4l2_dev,
			 "error %d waiting for frame completion\n", ret);

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
		 "disabling connection\n");

	/* disable the connection from camera to encoder */
	ret = vchiq_mmal_port_disable(dev->instance, dev->capture.camera_port);
	if (!ret && dev->capture.camera_port != dev->capture.port) {
		v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
			 "disabling port\n");
		ret = vchiq_mmal_port_disable(dev->instance, dev->capture.port);
	} else if (dev->capture.camera_port != dev->capture.port) {
		v4l2_err(&dev->v4l2_dev, "port_disable failed, error %d\n",
			 ret);
	}

	if (disable_camera(dev) < 0)
		v4l2_err(&dev->v4l2_dev, "Failed to disable camera\n");
}

static void bm2835_mmal_lock(struct vb2_queue *vq)
{
	struct bm2835_mmal_dev *dev = vb2_get_drv_priv(vq);

	mutex_lock(&dev->mutex);
}

static void bm2835_mmal_unlock(struct vb2_queue *vq)
{
	struct bm2835_mmal_dev *dev = vb2_get_drv_priv(vq);

	mutex_unlock(&dev->mutex);
}

static struct vb2_ops bm2835_mmal_video_qops = {
	.queue_setup = queue_setup,
	.buf_prepare = buffer_prepare,
	.buf_queue = buffer_queue,
	.start_streaming = start_streaming,
	.stop_streaming = stop_streaming,
	.wait_prepare = bm2835_mmal_unlock,
	.wait_finish = bm2835_mmal_lock,
};

/* ------------------------------------------------------------------
	IOCTL operations
   ------------------------------------------------------------------*/

static int set_overlay_params(struct bm2835_mmal_dev *dev,
			      struct vchiq_mmal_port *port)
{
	int ret;
	struct mmal_parameter_displayregion prev_config = {
	.set = MMAL_DISPLAY_SET_LAYER | MMAL_DISPLAY_SET_ALPHA |
	    MMAL_DISPLAY_SET_DEST_RECT | MMAL_DISPLAY_SET_FULLSCREEN,
	.layer = PREVIEW_LAYER,
	.alpha = dev->overlay.global_alpha,
	.fullscreen = 0,
	.dest_rect = {
		      .x = dev->overlay.w.left,
		      .y = dev->overlay.w.top,
		      .width = dev->overlay.w.width,
		      .height = dev->overlay.w.height,
		      },
	};
	ret = vchiq_mmal_port_parameter_set(dev->instance, port,
					    MMAL_PARAMETER_DISPLAYREGION,
					    &prev_config, sizeof(prev_config));

	return ret;
}

/* overlay ioctl */
static int vidioc_enum_fmt_vid_overlay(struct file *file, void *priv,
				       struct v4l2_fmtdesc *f)
{
	struct mmal_fmt *fmt;

	if (f->index >= ARRAY_SIZE(formats))
		return -EINVAL;

	fmt = &formats[f->index];

	strlcpy(f->description, fmt->name, sizeof(f->description));
	f->pixelformat = fmt->fourcc;
	f->flags = fmt->flags;

	return 0;
}

static int vidioc_g_fmt_vid_overlay(struct file *file, void *priv,
				    struct v4l2_format *f)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);

	f->fmt.win = dev->overlay;

	return 0;
}

static int vidioc_try_fmt_vid_overlay(struct file *file, void *priv,
				      struct v4l2_format *f)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);

	f->fmt.win.field = V4L2_FIELD_NONE;
	f->fmt.win.chromakey = 0;
	f->fmt.win.clips = NULL;
	f->fmt.win.clipcount = 0;
	f->fmt.win.bitmap = NULL;

	v4l_bound_align_image(&f->fmt.win.w.width, MIN_WIDTH, dev->max_width, 1,
			      &f->fmt.win.w.height, MIN_HEIGHT, dev->max_height,
			      1, 0);
	v4l_bound_align_image(&f->fmt.win.w.left, MIN_WIDTH, dev->max_width, 1,
			      &f->fmt.win.w.top, MIN_HEIGHT, dev->max_height,
			      1, 0);

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
		 "Overlay: Now w/h %dx%d l/t %dx%d\n",
		f->fmt.win.w.width, f->fmt.win.w.height,
		f->fmt.win.w.left, f->fmt.win.w.top);

	v4l2_dump_win_format(1,
			     bcm2835_v4l2_debug,
			     &dev->v4l2_dev,
			     &f->fmt.win,
			     __func__);
	return 0;
}

static int vidioc_s_fmt_vid_overlay(struct file *file, void *priv,
				    struct v4l2_format *f)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);

	vidioc_try_fmt_vid_overlay(file, priv, f);

	dev->overlay = f->fmt.win;
	if (dev->component[MMAL_COMPONENT_PREVIEW]->enabled) {
		set_overlay_params(dev,
				   &dev->component[MMAL_COMPONENT_PREVIEW]->input[0]);
	}

	return 0;
}

static int vidioc_overlay(struct file *file, void *f, unsigned int on)
{
	int ret;
	struct bm2835_mmal_dev *dev = video_drvdata(file);
	struct vchiq_mmal_port *src;
	struct vchiq_mmal_port *dst;

	if ((on && dev->component[MMAL_COMPONENT_PREVIEW]->enabled) ||
	    (!on && !dev->component[MMAL_COMPONENT_PREVIEW]->enabled))
		return 0;	/* already in requested state */

	src =
	    &dev->component[MMAL_COMPONENT_CAMERA]->
	    output[MMAL_CAMERA_PORT_PREVIEW];

	if (!on) {
		/* disconnect preview ports and disable component */
		ret = vchiq_mmal_port_disable(dev->instance, src);
		if (!ret)
			ret =
			    vchiq_mmal_port_connect_tunnel(dev->instance, src,
							   NULL);
		if (ret >= 0)
			ret = vchiq_mmal_component_disable(
					dev->instance,
					dev->component[MMAL_COMPONENT_PREVIEW]);

		disable_camera(dev);
		return ret;
	}

	/* set preview port format and connect it to output */
	dst = &dev->component[MMAL_COMPONENT_PREVIEW]->input[0];

	ret = vchiq_mmal_port_set_format(dev->instance, src);
	if (ret < 0)
		goto error;

	ret = set_overlay_params(dev, dst);
	if (ret < 0)
		goto error;

	if (enable_camera(dev) < 0)
		goto error;

	ret = vchiq_mmal_component_enable(
			dev->instance,
			dev->component[MMAL_COMPONENT_PREVIEW]);
	if (ret < 0)
		goto error;

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev, "connecting %p to %p\n",
		 src, dst);
	ret = vchiq_mmal_port_connect_tunnel(dev->instance, src, dst);
	if (!ret)
		ret = vchiq_mmal_port_enable(dev->instance, src, NULL);
error:
	return ret;
}

static int vidioc_g_fbuf(struct file *file, void *fh,
			 struct v4l2_framebuffer *a)
{
	/* The video overlay must stay within the framebuffer and can't be
	   positioned independently. */
	struct bm2835_mmal_dev *dev = video_drvdata(file);
	struct vchiq_mmal_port *preview_port =
		    &dev->component[MMAL_COMPONENT_CAMERA]->
		    output[MMAL_CAMERA_PORT_PREVIEW];

	a->capability = V4L2_FBUF_CAP_EXTERNOVERLAY |
			V4L2_FBUF_CAP_GLOBAL_ALPHA;
	a->flags = V4L2_FBUF_FLAG_OVERLAY;
	a->fmt.width = preview_port->es.video.width;
	a->fmt.height = preview_port->es.video.height;
	a->fmt.pixelformat = V4L2_PIX_FMT_YUV420;
	a->fmt.bytesperline = preview_port->es.video.width;
	a->fmt.sizeimage = (preview_port->es.video.width *
			       preview_port->es.video.height * 3) >> 1;
	a->fmt.colorspace = V4L2_COLORSPACE_SMPTE170M;

	return 0;
}

/* input ioctls */
static int vidioc_enum_input(struct file *file, void *priv,
			     struct v4l2_input *inp)
{
	/* only a single camera input */
	if (inp->index != 0)
		return -EINVAL;

	inp->type = V4L2_INPUT_TYPE_CAMERA;
	sprintf(inp->name, "Camera %u", inp->index);
	return 0;
}

static int vidioc_g_input(struct file *file, void *priv, unsigned int *i)
{
	*i = 0;
	return 0;
}

static int vidioc_s_input(struct file *file, void *priv, unsigned int i)
{
	if (i != 0)
		return -EINVAL;

	return 0;
}

/* capture ioctls */
static int vidioc_querycap(struct file *file, void *priv,
			   struct v4l2_capability *cap)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);
	u32 major;
	u32 minor;

	vchiq_mmal_version(dev->instance, &major, &minor);

	strcpy(cap->driver, "bm2835 mmal");
	snprintf(cap->card, sizeof(cap->card), "mmal service %d.%d",
		 major, minor);

	snprintf(cap->bus_info, sizeof(cap->bus_info),
		 "platform:%s", dev->v4l2_dev.name);
	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OVERLAY |
	    V4L2_CAP_STREAMING | V4L2_CAP_READWRITE;
	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;

	return 0;
}

static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
				   struct v4l2_fmtdesc *f)
{
	struct mmal_fmt *fmt;

	if (f->index >= ARRAY_SIZE(formats))
		return -EINVAL;

	fmt = &formats[f->index];

	strlcpy(f->description, fmt->name, sizeof(f->description));
	f->pixelformat = fmt->fourcc;
	f->flags = fmt->flags;

	return 0;
}

static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
				struct v4l2_format *f)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);

	f->fmt.pix.width = dev->capture.width;
	f->fmt.pix.height = dev->capture.height;
	f->fmt.pix.field = V4L2_FIELD_NONE;
	f->fmt.pix.pixelformat = dev->capture.fmt->fourcc;
	f->fmt.pix.bytesperline = dev->capture.stride;
	f->fmt.pix.sizeimage = dev->capture.buffersize;

	if (dev->capture.fmt->fourcc == V4L2_PIX_FMT_RGB24)
		f->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
	else if (dev->capture.fmt->fourcc == V4L2_PIX_FMT_JPEG)
		f->fmt.pix.colorspace = V4L2_COLORSPACE_JPEG;
	else
		f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
	f->fmt.pix.priv = 0;

	v4l2_dump_pix_format(1, bcm2835_v4l2_debug, &dev->v4l2_dev, &f->fmt.pix,
			     __func__);
	return 0;
}

static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
				  struct v4l2_format *f)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);
	struct mmal_fmt *mfmt;

	mfmt = get_format(f);
	if (!mfmt) {
		v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
			 "Fourcc format (0x%08x) unknown.\n",
			 f->fmt.pix.pixelformat);
		f->fmt.pix.pixelformat = formats[0].fourcc;
		mfmt = get_format(f);
	}

	f->fmt.pix.field = V4L2_FIELD_NONE;

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
		 "Clipping/aligning %dx%d format %08X\n",
		 f->fmt.pix.width, f->fmt.pix.height, f->fmt.pix.pixelformat);

	v4l_bound_align_image(&f->fmt.pix.width, MIN_WIDTH, dev->max_width, 1,
			      &f->fmt.pix.height, MIN_HEIGHT, dev->max_height,
			      1, 0);
	f->fmt.pix.bytesperline = f->fmt.pix.width * mfmt->ybbp;

	/* Image buffer has to be padded to allow for alignment, even though
	 * we then remove that padding before delivering the buffer.
	 */
	f->fmt.pix.sizeimage = ((f->fmt.pix.height + 15) & ~15) *
			(((f->fmt.pix.width + 31) & ~31) * mfmt->depth) >> 3;

	if ((mfmt->flags & V4L2_FMT_FLAG_COMPRESSED) &&
	    f->fmt.pix.sizeimage < MIN_BUFFER_SIZE)
		f->fmt.pix.sizeimage = MIN_BUFFER_SIZE;

	if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB24)
		f->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
	else if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_JPEG)
		f->fmt.pix.colorspace = V4L2_COLORSPACE_JPEG;
	else
		f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
	f->fmt.pix.priv = 0;

	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
		 "Now %dx%d format %08X\n",
		f->fmt.pix.width, f->fmt.pix.height, f->fmt.pix.pixelformat);

	v4l2_dump_pix_format(1, bcm2835_v4l2_debug, &dev->v4l2_dev, &f->fmt.pix,
			     __func__);
	return 0;
}

static int mmal_setup_components(struct bm2835_mmal_dev *dev,
				 struct v4l2_format *f)
{
	int ret;
	struct vchiq_mmal_port *port = NULL, *camera_port = NULL;
	struct vchiq_mmal_component *encode_component = NULL;
	struct mmal_fmt *mfmt = get_format(f);

	BUG_ON(!mfmt);

	if (dev->capture.encode_component) {
		v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
			 "vid_cap - disconnect previous tunnel\n");

		/* Disconnect any previous connection */
		vchiq_mmal_port_connect_tunnel(dev->instance,
					       dev->capture.camera_port, NULL);
		dev->capture.camera_port = NULL;
		ret = vchiq_mmal_component_disable(dev->instance,
						   dev->capture.
						   encode_component);
		if (ret)
			v4l2_err(&dev->v4l2_dev,
				 "Failed to disable encode component %d\n",
				 ret);

		dev->capture.encode_component = NULL;
	}
	/* format dependent port setup */
	switch (mfmt->mmal_component) {
	case MMAL_COMPONENT_CAMERA:
		/* Make a further decision on port based on resolution */
		if (f->fmt.pix.width <= max_video_width
		    && f->fmt.pix.height <= max_video_height)
			camera_port = port =
			    &dev->component[MMAL_COMPONENT_CAMERA]->
			    output[MMAL_CAMERA_PORT_VIDEO];
		else
			camera_port = port =
			    &dev->component[MMAL_COMPONENT_CAMERA]->
			    output[MMAL_CAMERA_PORT_CAPTURE];
		break;
	case MMAL_COMPONENT_IMAGE_ENCODE:
		encode_component = dev->component[MMAL_COMPONENT_IMAGE_ENCODE];
		port = &dev->component[MMAL_COMPONENT_IMAGE_ENCODE]->output[0];
		camera_port =
		    &dev->component[MMAL_COMPONENT_CAMERA]->
		    output[MMAL_CAMERA_PORT_CAPTURE];
		break;
	case MMAL_COMPONENT_VIDEO_ENCODE:
		encode_component = dev->component[MMAL_COMPONENT_VIDEO_ENCODE];
		port = &dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->output[0];
		camera_port =
		    &dev->component[MMAL_COMPONENT_CAMERA]->
		    output[MMAL_CAMERA_PORT_VIDEO];
		break;
	default:
		break;
	}

	if (!port)
		return -EINVAL;

	if (encode_component)
		camera_port->format.encoding = MMAL_ENCODING_OPAQUE;
	else
		camera_port->format.encoding = mfmt->mmal;

	if (dev->rgb_bgr_swapped) {
		if (camera_port->format.encoding == MMAL_ENCODING_RGB24)
			camera_port->format.encoding = MMAL_ENCODING_BGR24;
		else if (camera_port->format.encoding == MMAL_ENCODING_BGR24)
			camera_port->format.encoding = MMAL_ENCODING_RGB24;
	}

	camera_port->format.encoding_variant = 0;
	camera_port->es.video.width = f->fmt.pix.width;
	camera_port->es.video.height = f->fmt.pix.height;
	camera_port->es.video.crop.x = 0;
	camera_port->es.video.crop.y = 0;
	camera_port->es.video.crop.width = f->fmt.pix.width;
	camera_port->es.video.crop.height = f->fmt.pix.height;
	camera_port->es.video.frame_rate.num = 0;
	camera_port->es.video.frame_rate.den = 1;
	camera_port->es.video.color_space = MMAL_COLOR_SPACE_JPEG_JFIF;

	ret = vchiq_mmal_port_set_format(dev->instance, camera_port);

	if (!ret
	    && camera_port ==
	    &dev->component[MMAL_COMPONENT_CAMERA]->
	    output[MMAL_CAMERA_PORT_VIDEO]) {
		bool overlay_enabled =
		    !!dev->component[MMAL_COMPONENT_PREVIEW]->enabled;
		struct vchiq_mmal_port *preview_port =
		    &dev->component[MMAL_COMPONENT_CAMERA]->
		    output[MMAL_CAMERA_PORT_PREVIEW];
		/* Preview and encode ports need to match on resolution */
		if (overlay_enabled) {
			/* Need to disable the overlay before we can update
			 * the resolution
			 */
			ret =
			    vchiq_mmal_port_disable(dev->instance,
						    preview_port);
			if (!ret)
				ret =
				    vchiq_mmal_port_connect_tunnel(
						dev->instance,
						preview_port,
						NULL);
		}
		preview_port->es.video.width = f->fmt.pix.width;
		preview_port->es.video.height = f->fmt.pix.height;
		preview_port->es.video.crop.x = 0;
		preview_port->es.video.crop.y = 0;
		preview_port->es.video.crop.width = f->fmt.pix.width;
		preview_port->es.video.crop.height = f->fmt.pix.height;
		preview_port->es.video.frame_rate.num =
					  dev->capture.timeperframe.denominator;
		preview_port->es.video.frame_rate.den =
					  dev->capture.timeperframe.numerator;
		ret = vchiq_mmal_port_set_format(dev->instance, preview_port);
		if (overlay_enabled) {
			ret = vchiq_mmal_port_connect_tunnel(
				dev->instance,
				preview_port,
				&dev->component[MMAL_COMPONENT_PREVIEW]->input[0]);
			if (!ret)
				ret = vchiq_mmal_port_enable(dev->instance,
							     preview_port,
							     NULL);
		}
	}

	if (ret) {
		v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
			 "%s failed to set format %dx%d %08X\n", __func__,
			 f->fmt.pix.width, f->fmt.pix.height,
			 f->fmt.pix.pixelformat);
		/* ensure capture is not going to be tried */
		dev->capture.port = NULL;
	} else {
		if (encode_component) {
			v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
				 "vid_cap - set up encode comp\n");

			/* configure buffering */
			camera_port->current_buffer.size =
			    camera_port->recommended_buffer.size;
			camera_port->current_buffer.num =
			    camera_port->recommended_buffer.num;

			ret =
			    vchiq_mmal_port_connect_tunnel(
					dev->instance,
					camera_port,
					&encode_component->input[0]);
			if (ret) {
				v4l2_dbg(1, bcm2835_v4l2_debug,
					 &dev->v4l2_dev,
					 "%s failed to create connection\n",
					 __func__);
				/* ensure capture is not going to be tried */
				dev->capture.port = NULL;
			} else {
				port->es.video.width = f->fmt.pix.width;
				port->es.video.height = f->fmt.pix.height;
				port->es.video.crop.x = 0;
				port->es.video.crop.y = 0;
				port->es.video.crop.width = f->fmt.pix.width;
				port->es.video.crop.height = f->fmt.pix.height;
				port->es.video.frame_rate.num =
					  dev->capture.timeperframe.denominator;
				port->es.video.frame_rate.den =
					  dev->capture.timeperframe.numerator;

				port->format.encoding = mfmt->mmal;
				port->format.encoding_variant = 0;
				/* Set any encoding specific parameters */
				switch (mfmt->mmal_component) {
				case MMAL_COMPONENT_VIDEO_ENCODE:
					port->format.bitrate =
					    dev->capture.encode_bitrate;
					break;
				case MMAL_COMPONENT_IMAGE_ENCODE:
					/* Could set EXIF parameters here */
					break;
				default:
					break;
				}
				ret = vchiq_mmal_port_set_format(dev->instance,
								 port);
				if (ret)
					v4l2_dbg(1, bcm2835_v4l2_debug,
						 &dev->v4l2_dev,
						 "%s failed to set format %dx%d fmt %08X\n",
						 __func__,
						 f->fmt.pix.width,
						 f->fmt.pix.height,
						 f->fmt.pix.pixelformat
						 );
			}

			if (!ret) {
				ret = vchiq_mmal_component_enable(
						dev->instance,
						encode_component);
				if (ret) {
					v4l2_dbg(1, bcm2835_v4l2_debug,
						 &dev->v4l2_dev,
						 "%s Failed to enable encode components\n",
						 __func__);
				}
			}
			if (!ret) {
				/* configure buffering */
				port->current_buffer.num = 1;
				port->current_buffer.size =
				    f->fmt.pix.sizeimage;
				if (port->format.encoding ==
				    MMAL_ENCODING_JPEG) {
					v4l2_dbg(1, bcm2835_v4l2_debug,
						 &dev->v4l2_dev,
						 "JPG - buf size now %d was %d\n",
						 f->fmt.pix.sizeimage,
						 port->current_buffer.size);
					port->current_buffer.size =
					    (f->fmt.pix.sizeimage <
					     (100 << 10))
					    ? (100 << 10) : f->fmt.pix.
					    sizeimage;
				}
				v4l2_dbg(1, bcm2835_v4l2_debug,
					 &dev->v4l2_dev,
					 "vid_cap - cur_buf.size set to %d\n",
					 f->fmt.pix.sizeimage);
				port->current_buffer.alignment = 0;
			}
		} else {
			/* configure buffering */
			camera_port->current_buffer.num = 1;
			camera_port->current_buffer.size = f->fmt.pix.sizeimage;
			camera_port->current_buffer.alignment = 0;
		}

		if (!ret) {
			dev->capture.fmt = mfmt;
			dev->capture.stride = f->fmt.pix.bytesperline;
			dev->capture.width = camera_port->es.video.crop.width;
			dev->capture.height = camera_port->es.video.crop.height;
			dev->capture.buffersize = port->current_buffer.size;

			/* select port for capture */
			dev->capture.port = port;
			dev->capture.camera_port = camera_port;
			dev->capture.encode_component = encode_component;
			v4l2_dbg(1, bcm2835_v4l2_debug,
				 &dev->v4l2_dev,
				"Set dev->capture.fmt %08X, %dx%d, stride %d, size %d",
				port->format.encoding,
				dev->capture.width, dev->capture.height,
				dev->capture.stride, dev->capture.buffersize);
		}
	}

	/* todo: Need to convert the vchiq/mmal error into a v4l2 error. */
	return ret;
}

static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
				struct v4l2_format *f)
{
	int ret;
	struct bm2835_mmal_dev *dev = video_drvdata(file);
	struct mmal_fmt *mfmt;

	/* try the format to set valid parameters */
	ret = vidioc_try_fmt_vid_cap(file, priv, f);
	if (ret) {
		v4l2_err(&dev->v4l2_dev,
			 "vid_cap - vidioc_try_fmt_vid_cap failed\n");
		return ret;
	}

	/* if a capture is running refuse to set format */
	if (vb2_is_busy(&dev->capture.vb_vidq)) {
		v4l2_info(&dev->v4l2_dev, "%s device busy\n", __func__);
		return -EBUSY;
	}

	/* If the format is unsupported v4l2 says we should switch to
	 * a supported one and not return an error. */
	mfmt = get_format(f);
	if (!mfmt) {
		v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
			 "Fourcc format (0x%08x) unknown.\n",
			 f->fmt.pix.pixelformat);
		f->fmt.pix.pixelformat = formats[0].fourcc;
		mfmt = get_format(f);
	}

	ret = mmal_setup_components(dev, f);
	if (ret != 0) {
		v4l2_err(&dev->v4l2_dev,
			 "%s: failed to setup mmal components: %d\n",
			 __func__, ret);
		ret = -EINVAL;
	}

	return ret;
}

static int vidioc_enum_framesizes(struct file *file, void *fh,
			   struct v4l2_frmsizeenum *fsize)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);
	static const struct v4l2_frmsize_stepwise sizes = {
		MIN_WIDTH, 0, 2,
		MIN_HEIGHT, 0, 2
	};
	int i;

	if (fsize->index)
		return -EINVAL;
	for (i = 0; i < ARRAY_SIZE(formats); i++)
		if (formats[i].fourcc == fsize->pixel_format)
			break;
	if (i == ARRAY_SIZE(formats))
		return -EINVAL;
	fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
	fsize->stepwise = sizes;
	fsize->stepwise.max_width = dev->max_width;
	fsize->stepwise.max_height = dev->max_height;
	return 0;
}

/* timeperframe is arbitrary and continuous */
static int vidioc_enum_frameintervals(struct file *file, void *priv,
				      struct v4l2_frmivalenum *fival)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);
	int i;

	if (fival->index)
		return -EINVAL;

	for (i = 0; i < ARRAY_SIZE(formats); i++)
		if (formats[i].fourcc == fival->pixel_format)
			break;
	if (i == ARRAY_SIZE(formats))
		return -EINVAL;

	/* regarding width & height - we support any within range */
	if (fival->width < MIN_WIDTH || fival->width > dev->max_width ||
	    fival->height < MIN_HEIGHT || fival->height > dev->max_height)
		return -EINVAL;

	fival->type = V4L2_FRMIVAL_TYPE_CONTINUOUS;

	/* fill in stepwise (step=1.0 is required by V4L2 spec) */
	fival->stepwise.min  = tpf_min;
	fival->stepwise.max  = tpf_max;
	fival->stepwise.step = (struct v4l2_fract) {1, 1};

	return 0;
}

static int vidioc_g_parm(struct file *file, void *priv,
			 struct v4l2_streamparm *parm)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);

	if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
		return -EINVAL;

	parm->parm.capture.capability   = V4L2_CAP_TIMEPERFRAME;
	parm->parm.capture.timeperframe = dev->capture.timeperframe;
	parm->parm.capture.readbuffers  = 1;
	return 0;
}

#define FRACT_CMP(a, OP, b)	\
	((u64)(a).numerator * (b).denominator  OP  \
	 (u64)(b).numerator * (a).denominator)

static int vidioc_s_parm(struct file *file, void *priv,
			 struct v4l2_streamparm *parm)
{
	struct bm2835_mmal_dev *dev = video_drvdata(file);
	struct v4l2_fract tpf;
	struct mmal_parameter_rational fps_param;

	if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
		return -EINVAL;

	tpf = parm->parm.capture.timeperframe;

	/* tpf: {*, 0} resets timing; clip to [min, max]*/
	tpf = tpf.denominator ? tpf : tpf_default;
	tpf = FRACT_CMP(tpf, <, tpf_min) ? tpf_min : tpf;
	tpf = FRACT_CMP(tpf, >, tpf_max) ? tpf_max : tpf;

	dev->capture.timeperframe = tpf;
	parm->parm.capture.timeperframe = tpf;
	parm->parm.capture.readbuffers  = 1;
	parm->parm.capture.capability   = V4L2_CAP_TIMEPERFRAME;

	fps_param.num = 0;	/* Select variable fps, and then use
				 * FPS_RANGE to select the actual limits.
				 */
	fps_param.den = 1;
	set_framerate_params(dev);

	return 0;
}

static const struct v4l2_ioctl_ops camera0_ioctl_ops = {
	/* overlay */
	.vidioc_enum_fmt_vid_overlay = vidioc_enum_fmt_vid_overlay,
	.vidioc_g_fmt_vid_overlay = vidioc_g_fmt_vid_overlay,
	.vidioc_try_fmt_vid_overlay = vidioc_try_fmt_vid_overlay,
	.vidioc_s_fmt_vid_overlay = vidioc_s_fmt_vid_overlay,
	.vidioc_overlay = vidioc_overlay,
	.vidioc_g_fbuf = vidioc_g_fbuf,

	/* inputs */
	.vidioc_enum_input = vidioc_enum_input,
	.vidioc_g_input = vidioc_g_input,
	.vidioc_s_input = vidioc_s_input,

	/* capture */
	.vidioc_querycap = vidioc_querycap,
	.vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
	.vidioc_g_fmt_vid_cap = vidioc_g_fmt_vid_cap,
	.vidioc_try_fmt_vid_cap = vidioc_try_fmt_vid_cap,
	.vidioc_s_fmt_vid_cap = vidioc_s_fmt_vid_cap,

	/* buffer management */
	.vidioc_reqbufs = vb2_ioctl_reqbufs,
	.vidioc_create_bufs = vb2_ioctl_create_bufs,
	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
	.vidioc_querybuf = vb2_ioctl_querybuf,
	.vidioc_qbuf = vb2_ioctl_qbuf,
	.vidioc_dqbuf = vb2_ioctl_dqbuf,
	.vidioc_enum_framesizes = vidioc_enum_framesizes,
	.vidioc_enum_frameintervals = vidioc_enum_frameintervals,
	.vidioc_g_parm        = vidioc_g_parm,
	.vidioc_s_parm        = vidioc_s_parm,
	.vidioc_streamon = vb2_ioctl_streamon,
	.vidioc_streamoff = vb2_ioctl_streamoff,

	.vidioc_log_status = v4l2_ctrl_log_status,
	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static const struct v4l2_ioctl_ops camera0_ioctl_ops_gstreamer = {
	/* overlay */
	.vidioc_enum_fmt_vid_overlay = vidioc_enum_fmt_vid_overlay,
	.vidioc_g_fmt_vid_overlay = vidioc_g_fmt_vid_overlay,
	.vidioc_try_fmt_vid_overlay = vidioc_try_fmt_vid_overlay,
	.vidioc_s_fmt_vid_overlay = vidioc_s_fmt_vid_overlay,
	.vidioc_overlay = vidioc_overlay,
	.vidioc_g_fbuf = vidioc_g_fbuf,

	/* inputs */
	.vidioc_enum_input = vidioc_enum_input,
	.vidioc_g_input = vidioc_g_input,
	.vidioc_s_input = vidioc_s_input,

	/* capture */
	.vidioc_querycap = vidioc_querycap,
	.vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
	.vidioc_g_fmt_vid_cap = vidioc_g_fmt_vid_cap,
	.vidioc_try_fmt_vid_cap = vidioc_try_fmt_vid_cap,
	.vidioc_s_fmt_vid_cap = vidioc_s_fmt_vid_cap,

	/* buffer management */
	.vidioc_reqbufs = vb2_ioctl_reqbufs,
	.vidioc_create_bufs = vb2_ioctl_create_bufs,
	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
	.vidioc_querybuf = vb2_ioctl_querybuf,
	.vidioc_qbuf = vb2_ioctl_qbuf,
	.vidioc_dqbuf = vb2_ioctl_dqbuf,
	/* Remove this function ptr to fix gstreamer bug
	.vidioc_enum_framesizes = vidioc_enum_framesizes, */
	.vidioc_enum_frameintervals = vidioc_enum_frameintervals,
	.vidioc_g_parm        = vidioc_g_parm,
	.vidioc_s_parm        = vidioc_s_parm,
	.vidioc_streamon = vb2_ioctl_streamon,
	.vidioc_streamoff = vb2_ioctl_streamoff,

	.vidioc_log_status = v4l2_ctrl_log_status,
	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

/* ------------------------------------------------------------------
	Driver init/finalise
   ------------------------------------------------------------------*/

static const struct v4l2_file_operations camera0_fops = {
	.owner = THIS_MODULE,
	.open = v4l2_fh_open,
	.release = vb2_fop_release,
	.read = vb2_fop_read,
	.poll = vb2_fop_poll,
	.unlocked_ioctl = video_ioctl2,	/* V4L2 ioctl handler */
	.mmap = vb2_fop_mmap,
};

static struct video_device vdev_template = {
	.name = "camera0",
	.fops = &camera0_fops,
	.ioctl_ops = &camera0_ioctl_ops,
	.release = video_device_release_empty,
};

/* Returns the number of cameras, and also the max resolution supported
 * by those cameras.
 */
static int get_num_cameras(struct vchiq_mmal_instance *instance,
			   unsigned int resolutions[][2], int num_resolutions)
{
	int ret;
	struct vchiq_mmal_component  *cam_info_component;
	struct mmal_parameter_camera_info_t cam_info = {0};
	int param_size = sizeof(cam_info);
	int i;

	/* create a camera_info component */
	ret = vchiq_mmal_component_init(instance, "camera_info",
					&cam_info_component);
	if (ret < 0)
		/* Unusual failure - let's guess one camera. */
		return 1;

	if (vchiq_mmal_port_parameter_get(instance,
					  &cam_info_component->control,
					  MMAL_PARAMETER_CAMERA_INFO,
					  &cam_info,
					  &param_size)) {
		pr_info("Failed to get camera info\n");
	}
	for (i = 0;
	     i < (cam_info.num_cameras > num_resolutions ?
			num_resolutions :
			cam_info.num_cameras);
	     i++) {
		resolutions[i][0] = cam_info.cameras[i].max_width;
		resolutions[i][1] = cam_info.cameras[i].max_height;
	}

	vchiq_mmal_component_finalise(instance,
				      cam_info_component);

	return cam_info.num_cameras;
}

static int set_camera_parameters(struct vchiq_mmal_instance *instance,
				 struct vchiq_mmal_component *camera,
				 struct bm2835_mmal_dev *dev)
{
	int ret;
	struct mmal_parameter_camera_config cam_config = {
		.max_stills_w = dev->max_width,
		.max_stills_h = dev->max_height,
		.stills_yuv422 = 1,
		.one_shot_stills = 1,
		.max_preview_video_w = (max_video_width > 1920) ?
						max_video_width : 1920,
		.max_preview_video_h = (max_video_height > 1088) ?
						max_video_height : 1088,
		.num_preview_video_frames = 3,
		.stills_capture_circular_buffer_height = 0,
		.fast_preview_resume = 0,
		.use_stc_timestamp = MMAL_PARAM_TIMESTAMP_MODE_RAW_STC
	};

	ret = vchiq_mmal_port_parameter_set(instance, &camera->control,
					    MMAL_PARAMETER_CAMERA_CONFIG,
					    &cam_config, sizeof(cam_config));
	return ret;
}

#define MAX_SUPPORTED_ENCODINGS 20

/* MMAL instance and component init */
static int __init mmal_init(struct bm2835_mmal_dev *dev)
{
	int ret;
	struct mmal_es_format *format;
	u32 bool_true = 1;
	u32 supported_encodings[MAX_SUPPORTED_ENCODINGS];
	int param_size;
	struct vchiq_mmal_component  *camera;

	ret = vchiq_mmal_init(&dev->instance);
	if (ret < 0)
		return ret;

	/* get the camera component ready */
	ret = vchiq_mmal_component_init(dev->instance, "ril.camera",
					&dev->component[MMAL_COMPONENT_CAMERA]);
	if (ret < 0)
		goto unreg_mmal;

	camera = dev->component[MMAL_COMPONENT_CAMERA];
	if (camera->outputs <  MMAL_CAMERA_PORT_COUNT) {
		ret = -EINVAL;
		goto unreg_camera;
	}

	ret = set_camera_parameters(dev->instance,
				    camera,
				    dev);
	if (ret < 0)
		goto unreg_camera;

	/* There was an error in the firmware that meant the camera component
	 * produced BGR instead of RGB.
	 * This is now fixed, but in order to support the old firmwares, we
	 * have to check.
	 */
	dev->rgb_bgr_swapped = true;
	param_size = sizeof(supported_encodings);
	ret = vchiq_mmal_port_parameter_get(dev->instance,
					    &camera->output[MMAL_CAMERA_PORT_CAPTURE],
					    MMAL_PARAMETER_SUPPORTED_ENCODINGS,
					    &supported_encodings,
					    &param_size);
	if (ret == 0) {
		int i;

		for (i = 0; i < param_size / sizeof(u32); i++) {
			if (supported_encodings[i] == MMAL_ENCODING_BGR24) {
				/* Found BGR24 first - old firmware. */
				break;
			}
			if (supported_encodings[i] == MMAL_ENCODING_RGB24) {
				/* Found RGB24 first
				 * new firmware, so use RGB24.
				 */
				dev->rgb_bgr_swapped = false;
			break;
			}
		}
	}
	format = &camera->output[MMAL_CAMERA_PORT_PREVIEW].format;

	format->encoding = MMAL_ENCODING_OPAQUE;
	format->encoding_variant = MMAL_ENCODING_I420;

	format->es->video.width = 1024;
	format->es->video.height = 768;
	format->es->video.crop.x = 0;
	format->es->video.crop.y = 0;
	format->es->video.crop.width = 1024;
	format->es->video.crop.height = 768;
	format->es->video.frame_rate.num = 0; /* Rely on fps_range */
	format->es->video.frame_rate.den = 1;

	format = &camera->output[MMAL_CAMERA_PORT_VIDEO].format;

	format->encoding = MMAL_ENCODING_OPAQUE;
	format->encoding_variant = MMAL_ENCODING_I420;

	format->es->video.width = 1024;
	format->es->video.height = 768;
	format->es->video.crop.x = 0;
	format->es->video.crop.y = 0;
	format->es->video.crop.width = 1024;
	format->es->video.crop.height = 768;
	format->es->video.frame_rate.num = 0; /* Rely on fps_range */
	format->es->video.frame_rate.den = 1;

	vchiq_mmal_port_parameter_set(dev->instance,
				      &camera->output[MMAL_CAMERA_PORT_VIDEO],
				      MMAL_PARAMETER_NO_IMAGE_PADDING,
				      &bool_true, sizeof(bool_true));

	format = &camera->output[MMAL_CAMERA_PORT_CAPTURE].format;

	format->encoding = MMAL_ENCODING_OPAQUE;

	format->es->video.width = 2592;
	format->es->video.height = 1944;
	format->es->video.crop.x = 0;
	format->es->video.crop.y = 0;
	format->es->video.crop.width = 2592;
	format->es->video.crop.height = 1944;
	format->es->video.frame_rate.num = 0; /* Rely on fps_range */
	format->es->video.frame_rate.den = 1;

	dev->capture.width = format->es->video.width;
	dev->capture.height = format->es->video.height;
	dev->capture.fmt = &formats[0];
	dev->capture.encode_component = NULL;
	dev->capture.timeperframe = tpf_default;
	dev->capture.enc_profile = V4L2_MPEG_VIDEO_H264_PROFILE_HIGH;
	dev->capture.enc_level = V4L2_MPEG_VIDEO_H264_LEVEL_4_0;

	vchiq_mmal_port_parameter_set(dev->instance,
				      &camera->output[MMAL_CAMERA_PORT_CAPTURE],
				      MMAL_PARAMETER_NO_IMAGE_PADDING,
				      &bool_true, sizeof(bool_true));

	/* get the preview component ready */
	ret = vchiq_mmal_component_init(
			dev->instance, "ril.video_render",
			&dev->component[MMAL_COMPONENT_PREVIEW]);
	if (ret < 0)
		goto unreg_camera;

	if (dev->component[MMAL_COMPONENT_PREVIEW]->inputs < 1) {
		ret = -EINVAL;
		pr_debug("too few input ports %d needed %d\n",
			 dev->component[MMAL_COMPONENT_PREVIEW]->inputs, 1);
		goto unreg_preview;
	}

	/* get the image encoder component ready */
	ret = vchiq_mmal_component_init(
		dev->instance, "ril.image_encode",
		&dev->component[MMAL_COMPONENT_IMAGE_ENCODE]);
	if (ret < 0)
		goto unreg_preview;

	if (dev->component[MMAL_COMPONENT_IMAGE_ENCODE]->inputs < 1) {
		ret = -EINVAL;
		v4l2_err(&dev->v4l2_dev, "too few input ports %d needed %d\n",
			 dev->component[MMAL_COMPONENT_IMAGE_ENCODE]->inputs,
			 1);
		goto unreg_image_encoder;
	}

	/* get the video encoder component ready */
	ret = vchiq_mmal_component_init(dev->instance, "ril.video_encode",
					&dev->
					component[MMAL_COMPONENT_VIDEO_ENCODE]);
	if (ret < 0)
		goto unreg_image_encoder;

	if (dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->inputs < 1) {
		ret = -EINVAL;
		v4l2_err(&dev->v4l2_dev, "too few input ports %d needed %d\n",
			 dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->inputs,
			 1);
		goto unreg_vid_encoder;
	}

	{
		struct vchiq_mmal_port *encoder_port =
			&dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->output[0];
		encoder_port->format.encoding = MMAL_ENCODING_H264;
		ret = vchiq_mmal_port_set_format(dev->instance,
						 encoder_port);
	}

	{
		unsigned int enable = 1;

		vchiq_mmal_port_parameter_set(
			dev->instance,
			&dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->control,
			MMAL_PARAMETER_VIDEO_IMMUTABLE_INPUT,
			&enable, sizeof(enable));

		vchiq_mmal_port_parameter_set(dev->instance,
					      &dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->control,
					      MMAL_PARAMETER_MINIMISE_FRAGMENTATION,
					      &enable,
					      sizeof(enable));
	}
	ret = bm2835_mmal_set_all_camera_controls(dev);
	if (ret < 0)
		goto unreg_vid_encoder;

	return 0;

unreg_vid_encoder:
	pr_err("Cleanup: Destroy video encoder\n");
	vchiq_mmal_component_finalise(
		dev->instance,
		dev->component[MMAL_COMPONENT_VIDEO_ENCODE]);

unreg_image_encoder:
	pr_err("Cleanup: Destroy image encoder\n");
	vchiq_mmal_component_finalise(
		dev->instance,
		dev->component[MMAL_COMPONENT_IMAGE_ENCODE]);

unreg_preview:
	pr_err("Cleanup: Destroy video render\n");
	vchiq_mmal_component_finalise(dev->instance,
				      dev->component[MMAL_COMPONENT_PREVIEW]);

unreg_camera:
	pr_err("Cleanup: Destroy camera\n");
	vchiq_mmal_component_finalise(dev->instance,
				      dev->component[MMAL_COMPONENT_CAMERA]);

unreg_mmal:
	vchiq_mmal_finalise(dev->instance);
	return ret;
}

static int __init bm2835_mmal_init_device(struct bm2835_mmal_dev *dev,
					  struct video_device *vfd)
{
	int ret;

	*vfd = vdev_template;
	if (gst_v4l2src_is_broken) {
		v4l2_info(&dev->v4l2_dev,
			  "Work-around for gstreamer issue is active.\n");
		vfd->ioctl_ops = &camera0_ioctl_ops_gstreamer;
	}

	vfd->v4l2_dev = &dev->v4l2_dev;

	vfd->lock = &dev->mutex;

	vfd->queue = &dev->capture.vb_vidq;

	/* video device needs to be able to access instance data */
	video_set_drvdata(vfd, dev);

	ret = video_register_device(vfd,
				    VFL_TYPE_GRABBER,
				    video_nr[dev->camera_num]);
	if (ret < 0)
		return ret;

	v4l2_info(vfd->v4l2_dev,
		  "V4L2 device registered as %s - stills mode > %dx%d\n",
		  video_device_node_name(vfd),
		  max_video_width, max_video_height);

	return 0;
}

static void bcm2835_cleanup_instance(struct bm2835_mmal_dev *dev)
{
	if (!dev)
		return;

	v4l2_info(&dev->v4l2_dev, "unregistering %s\n",
		  video_device_node_name(&dev->vdev));

	video_unregister_device(&dev->vdev);

	if (dev->capture.encode_component) {
		v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
			 "mmal_exit - disconnect tunnel\n");
		vchiq_mmal_port_connect_tunnel(dev->instance,
					       dev->capture.camera_port, NULL);
		vchiq_mmal_component_disable(dev->instance,
					     dev->capture.encode_component);
	}
	vchiq_mmal_component_disable(dev->instance,
				     dev->component[MMAL_COMPONENT_CAMERA]);

	vchiq_mmal_component_finalise(dev->instance,
				      dev->
				      component[MMAL_COMPONENT_VIDEO_ENCODE]);

	vchiq_mmal_component_finalise(dev->instance,
				      dev->
				      component[MMAL_COMPONENT_IMAGE_ENCODE]);

	vchiq_mmal_component_finalise(dev->instance,
				      dev->component[MMAL_COMPONENT_PREVIEW]);

	vchiq_mmal_component_finalise(dev->instance,
				      dev->component[MMAL_COMPONENT_CAMERA]);

	v4l2_ctrl_handler_free(&dev->ctrl_handler);

	v4l2_device_unregister(&dev->v4l2_dev);

	kfree(dev);
}

static struct v4l2_format default_v4l2_format = {
	.fmt.pix.pixelformat = V4L2_PIX_FMT_JPEG,
	.fmt.pix.width = 1024,
	.fmt.pix.bytesperline = 0,
	.fmt.pix.height = 768,
	.fmt.pix.sizeimage = 1024 * 768,
};

static int __init bm2835_mmal_init(void)
{
	int ret;
	struct bm2835_mmal_dev *dev;
	struct vb2_queue *q;
	int camera;
	unsigned int num_cameras;
	struct vchiq_mmal_instance *instance;
	unsigned int resolutions[MAX_BCM2835_CAMERAS][2];

	ret = vchiq_mmal_init(&instance);
	if (ret < 0)
		return ret;

	num_cameras = get_num_cameras(instance,
				      resolutions,
				      MAX_BCM2835_CAMERAS);
	if (num_cameras > MAX_BCM2835_CAMERAS)
		num_cameras = MAX_BCM2835_CAMERAS;

	for (camera = 0; camera < num_cameras; camera++) {
		dev = kzalloc(sizeof(struct bm2835_mmal_dev), GFP_KERNEL);
		if (!dev)
			return -ENOMEM;

		dev->camera_num = camera;
		dev->max_width = resolutions[camera][0];
		dev->max_height = resolutions[camera][1];

		/* setup device defaults */
		dev->overlay.w.left = 150;
		dev->overlay.w.top = 50;
		dev->overlay.w.width = 1024;
		dev->overlay.w.height = 768;
		dev->overlay.clipcount = 0;
		dev->overlay.field = V4L2_FIELD_NONE;
		dev->overlay.global_alpha = 255;

		dev->capture.fmt = &formats[3]; /* JPEG */

		/* v4l device registration */
		snprintf(dev->v4l2_dev.name, sizeof(dev->v4l2_dev.name),
			 "%s", BM2835_MMAL_MODULE_NAME);
		ret = v4l2_device_register(NULL, &dev->v4l2_dev);
		if (ret)
			goto free_dev;

		/* setup v4l controls */
		ret = bm2835_mmal_init_controls(dev, &dev->ctrl_handler);
		if (ret < 0)
			goto unreg_dev;
		dev->v4l2_dev.ctrl_handler = &dev->ctrl_handler;

		/* mmal init */
		dev->instance = instance;
		ret = mmal_init(dev);
		if (ret < 0)
			goto unreg_dev;

		/* initialize queue */
		q = &dev->capture.vb_vidq;
		memset(q, 0, sizeof(*q));
		q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
		q->io_modes = VB2_MMAP | VB2_USERPTR | VB2_READ;
		q->drv_priv = dev;
		q->buf_struct_size = sizeof(struct mmal_buffer);
		q->ops = &bm2835_mmal_video_qops;
		q->mem_ops = &vb2_vmalloc_memops;
		q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
		ret = vb2_queue_init(q);
		if (ret < 0)
			goto unreg_dev;

		/* v4l2 core mutex used to protect all fops and v4l2 ioctls. */
		mutex_init(&dev->mutex);

		/* initialise video devices */
		ret = bm2835_mmal_init_device(dev, &dev->vdev);
		if (ret < 0)
			goto unreg_dev;

		/* Really want to call vidioc_s_fmt_vid_cap with the default
		 * format, but currently the APIs don't join up.
		 */
		ret = mmal_setup_components(dev, &default_v4l2_format);
		if (ret < 0) {
			v4l2_err(&dev->v4l2_dev,
				 "%s: could not setup components\n", __func__);
			goto unreg_dev;
		}

		v4l2_info(&dev->v4l2_dev,
			  "Broadcom 2835 MMAL video capture ver %s loaded.\n",
			  BM2835_MMAL_VERSION);

		gdev[camera] = dev;
	}
	return 0;

unreg_dev:
	v4l2_ctrl_handler_free(&dev->ctrl_handler);
	v4l2_device_unregister(&dev->v4l2_dev);

free_dev:
	kfree(dev);

	for ( ; camera > 0; camera--) {
		bcm2835_cleanup_instance(gdev[camera]);
		gdev[camera] = NULL;
	}
	pr_info("%s: error %d while loading driver\n",
		BM2835_MMAL_MODULE_NAME, ret);

	return ret;
}

static void __exit bm2835_mmal_exit(void)
{
	int camera;
	struct vchiq_mmal_instance *instance = gdev[0]->instance;

	for (camera = 0; camera < MAX_BCM2835_CAMERAS; camera++) {
		bcm2835_cleanup_instance(gdev[camera]);
		gdev[camera] = NULL;
	}
	vchiq_mmal_finalise(instance);
}

module_init(bm2835_mmal_init);
module_exit(bm2835_mmal_exit);