staging: vc04_services: Add a V4L2 M2M codec driver
authorDave Stevenson <dave.stevenson@raspberrypi.org>
Tue, 25 Sep 2018 13:53:49 +0000 (14:53 +0100)
committerpopcornmix <popcornmix@gmail.com>
Wed, 1 Jul 2020 15:32:51 +0000 (16:32 +0100)
This adds a V4L2 memory to memory device that wraps the MMAL
video decode and video_encode components for H264 and MJPEG encode
and decode, MPEG4, H263, and VP8 decode (and MPEG2 decode
if the appropriate licence has been purchased).

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
drivers/staging/vc04_services/Kconfig
drivers/staging/vc04_services/Makefile
drivers/staging/vc04_services/bcm2835-codec/Kconfig [new file with mode: 0644]
drivers/staging/vc04_services/bcm2835-codec/Makefile [new file with mode: 0644]
drivers/staging/vc04_services/bcm2835-codec/TODO [new file with mode: 0644]
drivers/staging/vc04_services/bcm2835-codec/bcm2835-v4l2-codec.c [new file with mode: 0644]

index 697f354..0db6735 100644 (file)
@@ -24,6 +24,7 @@ source "drivers/staging/vc04_services/bcm2835-audio/Kconfig"
 source "drivers/staging/vc04_services/bcm2835-camera/Kconfig"
 source "drivers/staging/vc04_services/vchiq-mmal/Kconfig"
 source "drivers/staging/vc04_services/vc-sm-cma/Kconfig"
+source "drivers/staging/vc04_services/bcm2835-codec/Kconfig"
 
 endif
 
index c90ad85..709185d 100644 (file)
@@ -10,10 +10,11 @@ vchiq-objs := \
    interface/vchiq_arm/vchiq_util.o \
    interface/vchiq_arm/vchiq_connected.o \
 
-obj-$(CONFIG_SND_BCM2835)      += bcm2835-audio/
-obj-$(CONFIG_VIDEO_BCM2835)    += bcm2835-camera/
-obj-$(CONFIG_BCM2835_VCHIQ_MMAL) += vchiq-mmal/
-obj-$(CONFIG_BCM_VC_SM_CMA)    += vc-sm-cma/
+obj-$(CONFIG_SND_BCM2835)              += bcm2835-audio/
+obj-$(CONFIG_VIDEO_BCM2835)            += bcm2835-camera/
+obj-$(CONFIG_BCM2835_VCHIQ_MMAL)       += vchiq-mmal/
+obj-$(CONFIG_BCM_VC_SM_CMA)            += vc-sm-cma/
+obj-$(CONFIG_VIDEO_CODEC_BCM2835)      += bcm2835-codec/
 
 ccflags-y += -Idrivers/staging/vc04_services -D__VCCOREVER__=0x04000000
 
diff --git a/drivers/staging/vc04_services/bcm2835-codec/Kconfig b/drivers/staging/vc04_services/bcm2835-codec/Kconfig
new file mode 100644 (file)
index 0000000..951971b
--- /dev/null
@@ -0,0 +1,11 @@
+config VIDEO_CODEC_BCM2835
+       tristate "BCM2835 Video codec support"
+       depends on MEDIA_SUPPORT
+       depends on VIDEO_V4L2 && (ARCH_BCM2835 || COMPILE_TEST)
+       select BCM2835_VCHIQ_MMAL
+       select VIDEOBUF2_DMA_CONTIG
+       select V4L2_MEM2MEM_DEV
+       help
+         Say Y here to enable the V4L2 video codecs for
+         Broadcom BCM2835 SoC. This operates over the VCHIQ interface
+         to a service running on VideoCore.
diff --git a/drivers/staging/vc04_services/bcm2835-codec/Makefile b/drivers/staging/vc04_services/bcm2835-codec/Makefile
new file mode 100644 (file)
index 0000000..5820ec1
--- /dev/null
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+bcm2835-codec-objs := bcm2835-v4l2-codec.o
+
+obj-$(CONFIG_VIDEO_CODEC_BCM2835) += bcm2835-codec.o
+
+ccflags-y += \
+       -Idrivers/staging/vc04_services \
+       -D__VCCOREVER__=0x04000000
diff --git a/drivers/staging/vc04_services/bcm2835-codec/TODO b/drivers/staging/vc04_services/bcm2835-codec/TODO
new file mode 100644 (file)
index 0000000..ea9a7b7
--- /dev/null
@@ -0,0 +1,24 @@
+1) Convert to be a platform driver.
+
+Right now when the module probes, it tries to initialize VCHI and
+errors out if it wasn't ready yet.  If bcm2835-v4l2 was built in, then
+VCHI generally isn't ready because it depends on both the firmware and
+mailbox drivers having already loaded.
+
+We should have VCHI create a platform device once it's initialized,
+and have this driver bind to it, so that we automatically load the
+v4l2 module after VCHI loads.
+
+2) Support SELECTION API to define crop region on the image for encode.
+
+Particularly for resolutions that aren't a multiple of the macroblock
+size, the codec will report a resolution that is a multiple of the macroblock
+size (it has to have the memory to decode into), and then a different crop
+region within that buffer.
+The most common example is 1080P, where the buffer will be 1920x1088 with a
+crop region of 1920x1080.
+
+3) Refactor so that the component creation is only on queue_setup, not open.
+
+Fixes v4l2-compliance failure on trying to open 100 instances of the
+device.
\ No newline at end of file
diff --git a/drivers/staging/vc04_services/bcm2835-codec/bcm2835-v4l2-codec.c b/drivers/staging/vc04_services/bcm2835-codec/bcm2835-v4l2-codec.c
new file mode 100644 (file)
index 0000000..4e4e4fb
--- /dev/null
@@ -0,0 +1,2359 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * A v4l2-mem2mem device that wraps the video codec MMAL component.
+ *
+ * Copyright 2018 Raspberry Pi (Trading) Ltd.
+ * Author: Dave Stevenson (dave.stevenson@raspberrypi.org)
+ *
+ * Loosely based on the vim2m virtual driver by Pawel Osciak
+ * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
+ * Pawel Osciak, <pawel@osciak.com>
+ * Marek Szyprowski, <m.szyprowski@samsung.com>
+ *
+ * Whilst this driver uses the v4l2_mem2mem framework, it does not need the
+ * scheduling aspects, so will always take the buffers, pass them to the VPU,
+ * and then signal the job as complete.
+ *
+ * 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
+ */
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/syscalls.h>
+
+#include <media/v4l2-mem2mem.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <media/videobuf2-dma-contig.h>
+
+#include "vchiq-mmal/mmal-encodings.h"
+#include "vchiq-mmal/mmal-msg.h"
+#include "vchiq-mmal/mmal-parameters.h"
+#include "vchiq-mmal/mmal-vchiq.h"
+
+/*
+ * Default /dev/videoN node numbers for decode and encode.
+ * Deliberately avoid the very low numbers as these are often taken by webcams
+ * etc, and simple apps tend to only go for /dev/video0.
+ */
+static int decode_video_nr = 10;
+module_param(decode_video_nr, int, 0644);
+MODULE_PARM_DESC(decode_video_nr, "decoder video device number");
+
+static int encode_video_nr = 11;
+module_param(encode_video_nr, int, 0644);
+MODULE_PARM_DESC(encode_video_nr, "encoder video device number");
+
+static unsigned int debug;
+module_param(debug, uint, 0644);
+MODULE_PARM_DESC(debug, "activates debug info (0-3)");
+
+#define MIN_W          32
+#define MIN_H          32
+#define MAX_W          1920
+#define MAX_H          1088
+#define BPL_ALIGN      32
+#define DEFAULT_WIDTH  640
+#define DEFAULT_HEIGHT 480
+/*
+ * The unanswered question - what is the maximum size of a compressed frame?
+ * V4L2 mandates that the encoded frame must fit in a single buffer. Sizing
+ * that buffer is a compromise between wasting memory and risking not fitting.
+ * The 1080P version of Big Buck Bunny has some frames that exceed 512kB.
+ * Adopt a moderately arbitrary split at 720P for switching between 512 and
+ * 768kB buffers.
+ */
+#define DEF_COMP_BUF_SIZE_GREATER_720P (768 << 10)
+#define DEF_COMP_BUF_SIZE_720P_OR_LESS (512 << 10)
+
+/* Flags that indicate a format can be used for capture/output */
+#define MEM2MEM_CAPTURE                BIT(0)
+#define MEM2MEM_OUTPUT         BIT(1)
+
+#define MEM2MEM_NAME           "bcm2835-codec"
+
+struct bcm2835_codec_fmt {
+       u32     fourcc;
+       int     depth;
+       int     bytesperline_align;
+       u32     flags;
+       u32     mmal_fmt;
+       bool    decode_only;
+       bool    encode_only;
+       int     size_multiplier_x2;
+};
+
+/* Supported raw pixel formats. Those supported for both encode and decode
+ * must come first, with those only supported for decode coming after (there
+ * are no formats supported for encode only).
+ */
+static struct bcm2835_codec_fmt raw_formats[] = {
+       {
+               .fourcc                 = V4L2_PIX_FMT_YUV420,
+               .depth                  = 8,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_I420,
+               .size_multiplier_x2     = 3,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_YVU420,
+               .depth                  = 8,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_YV12,
+               .size_multiplier_x2     = 3,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_NV12,
+               .depth                  = 8,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_NV12,
+               .size_multiplier_x2     = 3,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_NV21,
+               .depth                  = 8,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_NV21,
+               .size_multiplier_x2     = 3,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_RGB565,
+               .depth                  = 16,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_RGB16,
+               .size_multiplier_x2     = 2,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_YUYV,
+               .depth                  = 16,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_YUYV,
+               .encode_only            = true,
+               .size_multiplier_x2     = 2,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_UYVY,
+               .depth                  = 16,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_UYVY,
+               .encode_only            = true,
+               .size_multiplier_x2     = 2,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_YVYU,
+               .depth                  = 16,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_YVYU,
+               .encode_only            = true,
+               .size_multiplier_x2     = 2,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_VYUY,
+               .depth                  = 16,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_VYUY,
+               .encode_only            = true,
+               .size_multiplier_x2     = 2,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_RGB24,
+               .depth                  = 24,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_RGB24,
+               .encode_only            = true,
+               .size_multiplier_x2     = 2,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_BGR24,
+               .depth                  = 24,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_BGR24,
+               .encode_only            = true,
+               .size_multiplier_x2     = 2,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_BGR32,
+               .depth                  = 32,
+               .bytesperline_align     = 32,
+               .flags                  = 0,
+               .mmal_fmt               = MMAL_ENCODING_BGRA,
+               .encode_only            = true,
+               .size_multiplier_x2     = 2,
+       },
+};
+
+/* Supported encoded formats. Those supported for both encode and decode
+ * must come first, with those only supported for decode coming after (there
+ * are no formats supported for encode only).
+ */
+static struct bcm2835_codec_fmt encoded_formats[] = {
+       {
+               .fourcc                 = V4L2_PIX_FMT_H264,
+               .depth                  = 0,
+               .flags                  = V4L2_FMT_FLAG_COMPRESSED,
+               .mmal_fmt               = MMAL_ENCODING_H264,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_MJPEG,
+               .depth                  = 0,
+               .flags                  = V4L2_FMT_FLAG_COMPRESSED,
+               .mmal_fmt               = MMAL_ENCODING_MJPEG,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_MPEG4,
+               .depth                  = 0,
+               .flags                  = V4L2_FMT_FLAG_COMPRESSED,
+               .mmal_fmt               = MMAL_ENCODING_MP4V,
+               .decode_only            = true,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_H263,
+               .depth                  = 0,
+               .flags                  = V4L2_FMT_FLAG_COMPRESSED,
+               .mmal_fmt               = MMAL_ENCODING_H263,
+               .decode_only            = true,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_MPEG2,
+               .depth                  = 0,
+               .flags                  = V4L2_FMT_FLAG_COMPRESSED,
+               .mmal_fmt               = MMAL_ENCODING_MP2V,
+               .decode_only            = true,
+       }, {
+               .fourcc                 = V4L2_PIX_FMT_VP8,
+               .depth                  = 0,
+               .flags                  = V4L2_FMT_FLAG_COMPRESSED,
+               .mmal_fmt               = MMAL_ENCODING_VP8,
+               .decode_only            = true,
+       },
+       /*
+        * This list couold include VP6 and Theorafor decode, but V4L2 doesn't
+        * support them.
+        */
+};
+
+struct bcm2835_codec_fmt_list {
+       struct bcm2835_codec_fmt *list;
+       unsigned int num_entries;
+};
+
+#define RAW_LIST       0
+#define ENCODED_LIST   1
+
+struct bcm2835_codec_fmt_list formats[] = {
+       {
+               .list = raw_formats,
+               .num_entries = ARRAY_SIZE(raw_formats),
+       }, {
+               .list = encoded_formats,
+               .num_entries = ARRAY_SIZE(encoded_formats),
+       },
+};
+
+struct m2m_mmal_buffer {
+       struct v4l2_m2m_buffer  m2m;
+       struct mmal_buffer      mmal;
+};
+
+/* Per-queue, driver-specific private data */
+struct bcm2835_codec_q_data {
+       /*
+        * These parameters should be treated as gospel, with everything else
+        * being determined from them.
+        */
+       /* Buffer width/height */
+       unsigned int            bytesperline;
+       unsigned int            height;
+       /* Crop size used for selection handling */
+       unsigned int            crop_width;
+       unsigned int            crop_height;
+       bool                    selection_set;
+
+       unsigned int            sizeimage;
+       unsigned int            sequence;
+       struct bcm2835_codec_fmt        *fmt;
+
+       /* One extra buffer header so we can send an EOS. */
+       struct m2m_mmal_buffer  eos_buffer;
+       bool                    eos_buffer_in_use;      /* debug only */
+};
+
+enum {
+       V4L2_M2M_SRC = 0,
+       V4L2_M2M_DST = 1,
+};
+
+static inline struct bcm2835_codec_fmt_list *get_format_list(bool decode,
+                                                            bool capture)
+{
+       return decode ^ capture ? &formats[ENCODED_LIST] : &formats[RAW_LIST];
+}
+
+static struct bcm2835_codec_fmt *get_default_format(bool decode, bool capture)
+{
+       return &get_format_list(decode, capture)->list[0];
+}
+
+static struct bcm2835_codec_fmt *find_format(struct v4l2_format *f, bool decode,
+                                            bool capture)
+{
+       struct bcm2835_codec_fmt *fmt;
+       unsigned int k;
+       struct bcm2835_codec_fmt_list *fmts = get_format_list(decode, capture);
+
+       for (k = 0; k < fmts->num_entries; k++) {
+               fmt = &fmts->list[k];
+               if (fmt->fourcc == f->fmt.pix.pixelformat)
+                       break;
+       }
+
+       /*
+        * Some compressed formats are only supported for decoding, not
+        * encoding.
+        */
+       if (!decode && fmts->list[k].decode_only)
+               return NULL;
+
+       /* Some pixel formats are only supported for encoding, not decoding. */
+       if (decode && fmts->list[k].encode_only)
+               return NULL;
+
+       if (k == fmts->num_entries)
+               return NULL;
+
+       return &fmts->list[k];
+}
+
+struct bcm2835_codec_dev {
+       struct platform_device *pdev;
+
+       /* v4l2 devices */
+       struct v4l2_device      v4l2_dev;
+       struct video_device     vfd;
+       /* mutex for the v4l2 device */
+       struct mutex            dev_mutex;
+       atomic_t                num_inst;
+
+       /* allocated mmal instance and components */
+       bool                    decode;  /* Is this instance a decoder? */
+       struct vchiq_mmal_instance      *instance;
+
+       struct v4l2_m2m_dev     *m2m_dev;
+};
+
+struct bcm2835_codec_ctx {
+       struct v4l2_fh          fh;
+       struct bcm2835_codec_dev        *dev;
+
+       struct v4l2_ctrl_handler hdl;
+
+       struct vchiq_mmal_component  *component;
+       bool component_enabled;
+
+       enum v4l2_colorspace    colorspace;
+       enum v4l2_ycbcr_encoding ycbcr_enc;
+       enum v4l2_xfer_func     xfer_func;
+       enum v4l2_quantization  quant;
+
+       /* Source and destination queue data */
+       struct bcm2835_codec_q_data   q_data[2];
+       s32  bitrate;
+
+       bool aborting;
+       int num_ip_buffers;
+       int num_op_buffers;
+       struct completion frame_cmplt;
+};
+
+struct bcm2835_codec_driver {
+       struct bcm2835_codec_dev *encode;
+       struct bcm2835_codec_dev *decode;
+};
+
+static inline struct bcm2835_codec_ctx *file2ctx(struct file *file)
+{
+       return container_of(file->private_data, struct bcm2835_codec_ctx, fh);
+}
+
+static struct bcm2835_codec_q_data *get_q_data(struct bcm2835_codec_ctx *ctx,
+                                              enum v4l2_buf_type type)
+{
+       switch (type) {
+       case V4L2_BUF_TYPE_VIDEO_OUTPUT:
+               return &ctx->q_data[V4L2_M2M_SRC];
+       case V4L2_BUF_TYPE_VIDEO_CAPTURE:
+               return &ctx->q_data[V4L2_M2M_DST];
+       default:
+               v4l2_err(&ctx->dev->v4l2_dev, "%s: Invalid queue type %u\n",
+                        __func__, type);
+               break;
+       }
+       return NULL;
+}
+
+static struct vchiq_mmal_port *get_port_data(struct bcm2835_codec_ctx *ctx,
+                                            enum v4l2_buf_type type)
+{
+       if (!ctx->component)
+               return NULL;
+
+       switch (type) {
+       case V4L2_BUF_TYPE_VIDEO_OUTPUT:
+               return &ctx->component->input[0];
+       case V4L2_BUF_TYPE_VIDEO_CAPTURE:
+               return &ctx->component->output[0];
+       default:
+               v4l2_err(&ctx->dev->v4l2_dev, "%s: Invalid queue type %u\n",
+                        __func__, type);
+               break;
+       }
+       return NULL;
+}
+
+/*
+ * mem2mem callbacks
+ */
+
+/**
+ * job_ready() - check whether an instance is ready to be scheduled to run
+ */
+static int job_ready(void *priv)
+{
+       struct bcm2835_codec_ctx *ctx = priv;
+
+       if (!v4l2_m2m_num_src_bufs_ready(ctx->fh.m2m_ctx) &&
+           !v4l2_m2m_num_dst_bufs_ready(ctx->fh.m2m_ctx))
+               return 0;
+
+       return 1;
+}
+
+static void job_abort(void *priv)
+{
+       struct bcm2835_codec_ctx *ctx = priv;
+
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s\n", __func__);
+       /* Will cancel the transaction in the next interrupt handler */
+       ctx->aborting = 1;
+}
+
+static inline unsigned int get_sizeimage(int bpl, int height,
+                                        struct bcm2835_codec_fmt *fmt)
+{
+       return (bpl * height * fmt->size_multiplier_x2) >> 1;
+}
+
+static inline unsigned int get_bytesperline(int width,
+                                           struct bcm2835_codec_fmt *fmt)
+{
+       return ALIGN((width * fmt->depth) >> 3, fmt->bytesperline_align);
+}
+
+static void setup_mmal_port_format(struct bcm2835_codec_ctx *ctx,
+                                  bool decode,
+                                  struct bcm2835_codec_q_data *q_data,
+                                  struct vchiq_mmal_port *port)
+{
+       port->format.encoding = q_data->fmt->mmal_fmt;
+
+       if (!(q_data->fmt->flags & V4L2_FMT_FLAG_COMPRESSED)) {
+               /* Raw image format - set width/height */
+               port->es.video.width = q_data->bytesperline /
+                                               (q_data->fmt->depth >> 3);
+               port->es.video.height = q_data->height;
+               port->es.video.crop.width = q_data->crop_width;
+               port->es.video.crop.height = q_data->crop_height;
+               port->es.video.frame_rate.num = 0;
+               port->es.video.frame_rate.den = 1;
+       } else {
+               /* Compressed format - leave resolution as 0 for decode */
+               if (decode) {
+                       port->es.video.width = 0;
+                       port->es.video.height = 0;
+                       port->es.video.crop.width = 0;
+                       port->es.video.crop.height = 0;
+               } else {
+                       port->es.video.width = q_data->crop_width;
+                       port->es.video.height = q_data->height;
+                       port->es.video.crop.width = q_data->crop_width;
+                       port->es.video.crop.height = q_data->crop_height;
+                       port->format.bitrate = ctx->bitrate;
+               }
+               port->es.video.frame_rate.num = 0;
+               port->es.video.frame_rate.den = 1;
+       }
+       port->es.video.crop.x = 0;
+       port->es.video.crop.y = 0;
+
+       port->current_buffer.size = q_data->sizeimage;
+};
+
+static void ip_buffer_cb(struct vchiq_mmal_instance *instance,
+                        struct vchiq_mmal_port *port, int status,
+                        struct mmal_buffer *mmal_buf)
+{
+       struct bcm2835_codec_ctx *ctx = port->cb_ctx/*, *curr_ctx*/;
+       struct m2m_mmal_buffer *buf =
+                       container_of(mmal_buf, struct m2m_mmal_buffer, mmal);
+
+       v4l2_dbg(2, debug, &ctx->dev->v4l2_dev, "%s: port %p buf %p length %lu, flags %x\n",
+                __func__, port, mmal_buf, mmal_buf->length,
+                mmal_buf->mmal_flags);
+
+       if (buf == &ctx->q_data[V4L2_M2M_SRC].eos_buffer) {
+               /* Do we need to add lcoking to prevent multiple submission of
+                * the EOS, and therefore handle mutliple return here?
+                */
+               v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: eos buffer returned.\n",
+                        __func__);
+               ctx->q_data[V4L2_M2M_SRC].eos_buffer_in_use = false;
+               return;
+       }
+
+       if (status) {
+               /* error in transfer */
+               if (buf)
+                       /* there was a buffer with the error so return it */
+                       vb2_buffer_done(&buf->m2m.vb.vb2_buf,
+                                       VB2_BUF_STATE_ERROR);
+               return;
+       }
+       if (mmal_buf->cmd) {
+               v4l2_err(&ctx->dev->v4l2_dev, "%s: Not expecting cmd msgs on ip callback - %08x\n",
+                        __func__, mmal_buf->cmd);
+               /*
+                * CHECKME: Should we return here. The buffer shouldn't have a
+                * message context or vb2 buf associated.
+                */
+       }
+
+       v4l2_dbg(3, debug, &ctx->dev->v4l2_dev, "%s: no error. Return buffer %p\n",
+                __func__, &buf->m2m.vb.vb2_buf);
+       vb2_buffer_done(&buf->m2m.vb.vb2_buf, VB2_BUF_STATE_DONE);
+
+       ctx->num_ip_buffers++;
+       v4l2_dbg(2, debug, &ctx->dev->v4l2_dev, "%s: done %d input buffers\n",
+                __func__, ctx->num_ip_buffers);
+
+       if (!port->enabled)
+               complete(&ctx->frame_cmplt);
+}
+
+static void queue_res_chg_event(struct bcm2835_codec_ctx *ctx)
+{
+       static const struct v4l2_event ev_src_ch = {
+               .type = V4L2_EVENT_SOURCE_CHANGE,
+               .u.src_change.changes =
+               V4L2_EVENT_SRC_CH_RESOLUTION,
+       };
+
+       v4l2_event_queue_fh(&ctx->fh, &ev_src_ch);
+}
+
+static void send_eos_event(struct bcm2835_codec_ctx *ctx)
+{
+       static const struct v4l2_event ev = {
+               .type = V4L2_EVENT_EOS,
+       };
+
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "Sending EOS event\n");
+
+       v4l2_event_queue_fh(&ctx->fh, &ev);
+}
+
+static void color_mmal2v4l(struct bcm2835_codec_ctx *ctx, u32 mmal_color_space)
+{
+       switch (mmal_color_space) {
+       case MMAL_COLOR_SPACE_ITUR_BT601:
+               ctx->colorspace = V4L2_COLORSPACE_REC709;
+               ctx->xfer_func = V4L2_XFER_FUNC_709;
+               ctx->ycbcr_enc = V4L2_YCBCR_ENC_601;
+               ctx->quant = V4L2_QUANTIZATION_LIM_RANGE;
+               break;
+
+       case MMAL_COLOR_SPACE_ITUR_BT709:
+               ctx->colorspace = V4L2_COLORSPACE_REC709;
+               ctx->xfer_func = V4L2_XFER_FUNC_709;
+               ctx->ycbcr_enc = V4L2_YCBCR_ENC_709;
+               ctx->quant = V4L2_QUANTIZATION_LIM_RANGE;
+               break;
+       }
+}
+
+static void handle_fmt_changed(struct bcm2835_codec_ctx *ctx,
+                              struct mmal_buffer *mmal_buf)
+{
+       struct bcm2835_codec_q_data *q_data;
+       struct mmal_msg_event_format_changed *format =
+               (struct mmal_msg_event_format_changed *)mmal_buf->buffer;
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: Format changed: buff size min %u, rec %u, buff num min %u, rec %u\n",
+                __func__,
+                format->buffer_size_min,
+                format->buffer_size_recommended,
+                format->buffer_num_min,
+                format->buffer_num_recommended
+               );
+       if (format->format.type != MMAL_ES_TYPE_VIDEO) {
+               v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: Format changed but not video %u\n",
+                        __func__, format->format.type);
+               return;
+       }
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: Format changed to %ux%u, crop %ux%u, colourspace %08X\n",
+                __func__, format->es.video.width, format->es.video.height,
+                format->es.video.crop.width, format->es.video.crop.height,
+                format->es.video.color_space);
+
+       q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+       q_data->crop_width = format->es.video.crop.width;
+       q_data->crop_height = format->es.video.crop.height;
+       q_data->bytesperline = format->es.video.crop.width;
+       q_data->height = format->es.video.height;
+       q_data->sizeimage = format->buffer_size_min;
+       if (format->es.video.color_space)
+               color_mmal2v4l(ctx, format->es.video.color_space);
+
+       queue_res_chg_event(ctx);
+}
+
+static void op_buffer_cb(struct vchiq_mmal_instance *instance,
+                        struct vchiq_mmal_port *port, int status,
+                        struct mmal_buffer *mmal_buf)
+{
+       struct bcm2835_codec_ctx *ctx = port->cb_ctx;
+       struct m2m_mmal_buffer *buf;
+       struct vb2_v4l2_buffer *vb2;
+
+       v4l2_dbg(2, debug, &ctx->dev->v4l2_dev,
+                "%s: status:%d, buf:%p, length:%lu, flags %u, pts %lld\n",
+                __func__, status, mmal_buf, mmal_buf->length,
+                mmal_buf->mmal_flags, mmal_buf->pts);
+
+       if (status) {
+               /* error in transfer */
+               if (vb2) {
+                       /* there was a buffer with the error so return it */
+                       vb2_buffer_done(&vb2->vb2_buf, VB2_BUF_STATE_ERROR);
+               }
+               return;
+       }
+
+       if (mmal_buf->cmd) {
+               switch (mmal_buf->cmd) {
+               case MMAL_EVENT_FORMAT_CHANGED:
+               {
+                       handle_fmt_changed(ctx, mmal_buf);
+                       break;
+               }
+               default:
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Unexpected event on output callback - %08x\n",
+                                __func__, mmal_buf->cmd);
+                       break;
+               }
+               return;
+       }
+
+       buf = container_of(mmal_buf, struct m2m_mmal_buffer, mmal);
+       vb2 = &buf->m2m.vb;
+
+       v4l2_dbg(3, debug, &ctx->dev->v4l2_dev, "%s: length %lu, flags %x, idx %u\n",
+                __func__, mmal_buf->length, mmal_buf->mmal_flags,
+                vb2->vb2_buf.index);
+
+       if (mmal_buf->length == 0) {
+               /* stream ended, or buffer being returned during disable. */
+               v4l2_dbg(2, debug, &ctx->dev->v4l2_dev, "%s: Empty buffer - flags %04x",
+                        __func__, mmal_buf->mmal_flags);
+               if (!mmal_buf->mmal_flags & MMAL_BUFFER_HEADER_FLAG_EOS) {
+                       vb2_buffer_done(&vb2->vb2_buf, VB2_BUF_STATE_ERROR);
+                       if (!port->enabled)
+                               complete(&ctx->frame_cmplt);
+                       return;
+               }
+       }
+       if (mmal_buf->mmal_flags & MMAL_BUFFER_HEADER_FLAG_EOS) {
+               /* EOS packet from the VPU */
+               send_eos_event(ctx);
+               vb2->flags |= V4L2_BUF_FLAG_LAST;
+       }
+
+       vb2->vb2_buf.timestamp = mmal_buf->pts;
+
+       vb2_set_plane_payload(&vb2->vb2_buf, 0, mmal_buf->length);
+       if (mmal_buf->mmal_flags & MMAL_BUFFER_HEADER_FLAG_KEYFRAME)
+               vb2->flags |= V4L2_BUF_FLAG_KEYFRAME;
+
+       vb2_buffer_done(&vb2->vb2_buf, VB2_BUF_STATE_DONE);
+       ctx->num_op_buffers++;
+
+       v4l2_dbg(2, debug, &ctx->dev->v4l2_dev, "%s: done %d output buffers\n",
+                __func__, ctx->num_op_buffers);
+
+       if (!port->enabled)
+               complete(&ctx->frame_cmplt);
+}
+
+/* vb2_to_mmal_buffer() - converts vb2 buffer header to MMAL
+ *
+ * Copies all the required fields from a VB2 buffer to the MMAL buffer header,
+ * ready for sending to the VPU.
+ */
+static void vb2_to_mmal_buffer(struct m2m_mmal_buffer *buf,
+                              struct vb2_v4l2_buffer *vb2)
+{
+       buf->mmal.mmal_flags = 0;
+       if (vb2->flags & V4L2_BUF_FLAG_KEYFRAME)
+               buf->mmal.mmal_flags |= MMAL_BUFFER_HEADER_FLAG_KEYFRAME;
+
+       /*
+        * Adding this means that the data must be framed correctly as one frame
+        * per buffer. The underlying decoder has no such requirement, but it
+        * will reduce latency as the bistream parser will be kicked immediately
+        * to parse the frame, rather than relying on its own heuristics for
+        * when to wake up.
+        */
+       buf->mmal.mmal_flags |= MMAL_BUFFER_HEADER_FLAG_FRAME_END;
+
+       buf->mmal.length = vb2->vb2_buf.planes[0].bytesused;
+       /*
+        * Minor ambiguity in the V4L2 spec as to whether passing in a 0 length
+        * buffer, or one with V4L2_BUF_FLAG_LAST set denotes end of stream.
+        * Handle either.
+        */
+       if (!buf->mmal.length || vb2->flags & V4L2_BUF_FLAG_LAST)
+               buf->mmal.mmal_flags |= MMAL_BUFFER_HEADER_FLAG_EOS;
+
+       buf->mmal.pts = vb2->vb2_buf.timestamp;
+       buf->mmal.dts = MMAL_TIME_UNKNOWN;
+}
+
+/* device_run() - prepares and starts the device
+ *
+ * This simulates all the immediate preparations required before starting
+ * a device. This will be called by the framework when it decides to schedule
+ * a particular instance.
+ */
+static void device_run(void *priv)
+{
+       struct bcm2835_codec_ctx *ctx = priv;
+       struct bcm2835_codec_dev *dev = ctx->dev;
+       struct vb2_v4l2_buffer *src_buf, *dst_buf;
+       struct m2m_mmal_buffer *src_m2m_buf, *dst_m2m_buf;
+       struct v4l2_m2m_buffer *m2m;
+       int ret;
+
+       v4l2_dbg(3, debug, &ctx->dev->v4l2_dev, "%s: off we go\n", __func__);
+
+       src_buf = v4l2_m2m_buf_remove(&ctx->fh.m2m_ctx->out_q_ctx);
+       if (src_buf) {
+               m2m = container_of(src_buf, struct v4l2_m2m_buffer, vb);
+               src_m2m_buf = container_of(m2m, struct m2m_mmal_buffer, m2m);
+               vb2_to_mmal_buffer(src_m2m_buf, src_buf);
+
+               ret = vchiq_mmal_submit_buffer(dev->instance,
+                                              &ctx->component->input[0],
+                                              &src_m2m_buf->mmal);
+               v4l2_dbg(3, debug, &ctx->dev->v4l2_dev, "%s: Submitted ip buffer len %lu, pts %llu, flags %04x\n",
+                        __func__, src_m2m_buf->mmal.length,
+                        src_m2m_buf->mmal.pts, src_m2m_buf->mmal.mmal_flags);
+               if (ret)
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed submitting ip buffer\n",
+                                __func__);
+       }
+
+       dst_buf = v4l2_m2m_buf_remove(&ctx->fh.m2m_ctx->cap_q_ctx);
+       if (dst_buf) {
+               m2m = container_of(dst_buf, struct v4l2_m2m_buffer, vb);
+               dst_m2m_buf = container_of(m2m, struct m2m_mmal_buffer, m2m);
+               vb2_to_mmal_buffer(dst_m2m_buf, dst_buf);
+
+               ret = vchiq_mmal_submit_buffer(dev->instance,
+                                              &ctx->component->output[0],
+                                              &dst_m2m_buf->mmal);
+               if (ret)
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed submitting op buffer\n",
+                                __func__);
+       }
+
+       v4l2_dbg(3, debug, &ctx->dev->v4l2_dev, "%s: Submitted src %p, dst %p\n",
+                __func__, src_m2m_buf, dst_m2m_buf);
+
+       /* Complete the job here. */
+       v4l2_m2m_job_finish(ctx->dev->m2m_dev, ctx->fh.m2m_ctx);
+}
+
+/*
+ * video ioctls
+ */
+static int vidioc_querycap(struct file *file, void *priv,
+                          struct v4l2_capability *cap)
+{
+       strncpy(cap->driver, MEM2MEM_NAME, sizeof(cap->driver) - 1);
+       strncpy(cap->card, MEM2MEM_NAME, sizeof(cap->card) - 1);
+       snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
+                MEM2MEM_NAME);
+       cap->device_caps = V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;
+       cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
+       return 0;
+}
+
+static int enum_fmt(struct v4l2_fmtdesc *f, bool decode, bool capture)
+{
+       struct bcm2835_codec_fmt *fmt;
+       struct bcm2835_codec_fmt_list *fmts = get_format_list(decode, capture);
+
+       if (f->index < fmts->num_entries) {
+               /* Format found */
+               /* Check format isn't a decode only format when encoding */
+               if (!decode &&
+                   fmts->list[f->index].decode_only)
+                       return -EINVAL;
+               /* Check format isn't a decode only format when encoding */
+               if (decode &&
+                   fmts->list[f->index].encode_only)
+                       return -EINVAL;
+
+               fmt = &fmts->list[f->index];
+               f->pixelformat = fmt->fourcc;
+               f->flags = fmt->flags;
+               return 0;
+       }
+
+       /* Format not found */
+       return -EINVAL;
+}
+
+static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
+                                  struct v4l2_fmtdesc *f)
+{
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+
+       return enum_fmt(f, ctx->dev->decode, true);
+}
+
+static int vidioc_enum_fmt_vid_out(struct file *file, void *priv,
+                                  struct v4l2_fmtdesc *f)
+{
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+
+       return enum_fmt(f, ctx->dev->decode, false);
+}
+
+static int vidioc_g_fmt(struct bcm2835_codec_ctx *ctx, struct v4l2_format *f)
+{
+       struct vb2_queue *vq;
+       struct bcm2835_codec_q_data *q_data;
+
+       vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
+       if (!vq)
+               return -EINVAL;
+
+       q_data = get_q_data(ctx, f->type);
+
+       f->fmt.pix.width        = q_data->crop_width;
+       f->fmt.pix.height       = q_data->height;
+       f->fmt.pix.field        = V4L2_FIELD_NONE;
+       f->fmt.pix.pixelformat  = q_data->fmt->fourcc;
+       f->fmt.pix.bytesperline = q_data->bytesperline;
+       f->fmt.pix.sizeimage    = q_data->sizeimage;
+       f->fmt.pix.colorspace   = ctx->colorspace;
+       f->fmt.pix.xfer_func    = ctx->xfer_func;
+       f->fmt.pix.ycbcr_enc    = ctx->ycbcr_enc;
+       f->fmt.pix.quantization = ctx->quant;
+
+       return 0;
+}
+
+static int vidioc_g_fmt_vid_out(struct file *file, void *priv,
+                               struct v4l2_format *f)
+{
+       return vidioc_g_fmt(file2ctx(file), f);
+}
+
+static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
+                               struct v4l2_format *f)
+{
+       return vidioc_g_fmt(file2ctx(file), f);
+}
+
+static int vidioc_try_fmt(struct v4l2_format *f, struct bcm2835_codec_fmt *fmt)
+{
+       /*
+        * The V4L2 specification requires the driver to correct the format
+        * struct if any of the dimensions is unsupported
+        */
+       if (f->fmt.pix.width > MAX_W)
+               f->fmt.pix.width = MAX_W;
+       if (f->fmt.pix.height > MAX_H)
+               f->fmt.pix.height = MAX_H;
+
+       if (!fmt->flags & V4L2_FMT_FLAG_COMPRESSED) {
+               /* Only clip min w/h on capture. Treat 0x0 as unknown. */
+               if (f->fmt.pix.width < MIN_W)
+                       f->fmt.pix.width = MIN_W;
+               if (f->fmt.pix.height < MIN_H)
+                       f->fmt.pix.height = MIN_H;
+
+               /*
+                * Buffer must have a vertical alignment of 16 lines.
+                * The selection will reflect any cropping rectangle when only
+                * some of the pixels are active.
+                */
+               f->fmt.pix.height = ALIGN(f->fmt.pix.height, 16);
+
+               f->fmt.pix.bytesperline = get_bytesperline(f->fmt.pix.width,
+                                                          fmt);
+               f->fmt.pix.sizeimage = get_sizeimage(f->fmt.pix.bytesperline,
+                                                    f->fmt.pix.height,
+                                                    fmt);
+       } else {
+               u32 min_size = f->fmt.pix.width > 1280 ||
+                              f->fmt.pix.height > 720 ?
+                              DEF_COMP_BUF_SIZE_GREATER_720P :
+                              DEF_COMP_BUF_SIZE_720P_OR_LESS;
+
+               f->fmt.pix.bytesperline = 0;
+               if (f->fmt.pix.sizeimage < min_size)
+                       f->fmt.pix.sizeimage = min_size;
+       }
+
+       f->fmt.pix.field = V4L2_FIELD_NONE;
+
+       return 0;
+}
+
+static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
+                                 struct v4l2_format *f)
+{
+       struct bcm2835_codec_fmt *fmt;
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+
+       fmt = find_format(f, ctx->dev->decode, true);
+       if (!fmt) {
+               f->fmt.pix.pixelformat = get_default_format(ctx->dev->decode,
+                                                           true)->fourcc;
+               fmt = find_format(f, ctx->dev->decode, true);
+       }
+
+       return vidioc_try_fmt(f, fmt);
+}
+
+static int vidioc_try_fmt_vid_out(struct file *file, void *priv,
+                                 struct v4l2_format *f)
+{
+       struct bcm2835_codec_fmt *fmt;
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+
+       fmt = find_format(f, ctx->dev->decode, false);
+       if (!fmt) {
+               f->fmt.pix.pixelformat = get_default_format(ctx->dev->decode,
+                                                           false)->fourcc;
+               fmt = find_format(f, ctx->dev->decode, false);
+       }
+
+       if (!f->fmt.pix.colorspace)
+               f->fmt.pix.colorspace = ctx->colorspace;
+
+       return vidioc_try_fmt(f, fmt);
+}
+
+static int vidioc_s_fmt(struct bcm2835_codec_ctx *ctx, struct v4l2_format *f,
+                       unsigned int requested_height)
+{
+       struct bcm2835_codec_q_data *q_data;
+       struct vb2_queue *vq;
+       struct vchiq_mmal_port *port;
+       bool update_capture_port = false;
+       int ret;
+
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "Setting format for type %d, wxh: %dx%d, fmt: %08x, size %u\n",
+                f->type, f->fmt.pix.width, f->fmt.pix.height,
+                f->fmt.pix.pixelformat, f->fmt.pix.sizeimage);
+
+       vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
+       if (!vq)
+               return -EINVAL;
+
+       q_data = get_q_data(ctx, f->type);
+       if (!q_data)
+               return -EINVAL;
+
+       if (vb2_is_busy(vq)) {
+               v4l2_err(&ctx->dev->v4l2_dev, "%s queue busy\n", __func__);
+               return -EBUSY;
+       }
+
+       q_data->fmt = find_format(f, ctx->dev->decode,
+                                 f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE);
+       q_data->crop_width = f->fmt.pix.width;
+       q_data->height = f->fmt.pix.height;
+       if (!q_data->selection_set)
+               q_data->crop_height = requested_height;
+
+       /*
+        * Copying the behaviour of vicodec which retains a single set of
+        * colorspace parameters for both input and output.
+        */
+       ctx->colorspace = f->fmt.pix.colorspace;
+       ctx->xfer_func = f->fmt.pix.xfer_func;
+       ctx->ycbcr_enc = f->fmt.pix.ycbcr_enc;
+       ctx->quant = f->fmt.pix.quantization;
+
+       /* All parameters should have been set correctly by try_fmt */
+       q_data->bytesperline = f->fmt.pix.bytesperline;
+       q_data->sizeimage = f->fmt.pix.sizeimage;
+
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "Calulated bpl as %u, size %u\n",
+                q_data->bytesperline, q_data->sizeimage);
+
+       if (ctx->dev->decode && q_data->fmt->flags & V4L2_FMT_FLAG_COMPRESSED &&
+           f->fmt.pix.width && f->fmt.pix.height) {
+               /*
+                * On the decoder, if provided with a resolution on the input
+                * side, then replicate that to the output side.
+                * GStreamer appears not to support V4L2_EVENT_SOURCE_CHANGE,
+                * nor set up a resolution on the output side, therefore
+                * we can't decode anything at a resolution other than the
+                * default one.
+                */
+               struct bcm2835_codec_q_data *q_data_dst =
+                                               &ctx->q_data[V4L2_M2M_DST];
+
+               q_data_dst->crop_width = q_data->crop_width;
+               q_data_dst->crop_height = q_data->crop_height;
+               q_data_dst->height = ALIGN(q_data->crop_height, 16);
+
+               q_data_dst->bytesperline =
+                       get_bytesperline(f->fmt.pix.width, q_data_dst->fmt);
+               q_data_dst->sizeimage = get_sizeimage(q_data_dst->bytesperline,
+                                                     q_data_dst->height,
+                                                     q_data_dst->fmt);
+               update_capture_port = true;
+       }
+
+       /* If we have a component then setup the port as well */
+       port = get_port_data(ctx, vq->type);
+       if (!port)
+               return 0;
+
+       setup_mmal_port_format(ctx, ctx->dev->decode, q_data, port);
+       ret = vchiq_mmal_port_set_format(ctx->dev->instance, port);
+       if (ret) {
+               v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed vchiq_mmal_port_set_format on port, ret %d\n",
+                        __func__, ret);
+               ret = -EINVAL;
+       }
+
+       if (q_data->sizeimage < port->minimum_buffer.size) {
+               v4l2_err(&ctx->dev->v4l2_dev, "%s: Current buffer size of %u < min buf size %u - driver mismatch to MMAL\n",
+                        __func__, q_data->sizeimage,
+                        port->minimum_buffer.size);
+       }
+
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "Set format for type %d, wxh: %dx%d, fmt: %08x, size %u\n",
+                f->type, q_data->crop_width, q_data->height,
+                q_data->fmt->fourcc, q_data->sizeimage);
+
+       if (update_capture_port) {
+               struct vchiq_mmal_port *port_dst = &ctx->component->output[0];
+               struct bcm2835_codec_q_data *q_data_dst =
+                                               &ctx->q_data[V4L2_M2M_DST];
+
+               setup_mmal_port_format(ctx, ctx->dev->decode, q_data_dst,
+                                      port_dst);
+               ret = vchiq_mmal_port_set_format(ctx->dev->instance, port_dst);
+               if (ret) {
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed vchiq_mmal_port_set_format on output port, ret %d\n",
+                                __func__, ret);
+                       ret = -EINVAL;
+               }
+       }
+       return ret;
+}
+
+static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
+                               struct v4l2_format *f)
+{
+       unsigned int height = f->fmt.pix.height;
+       int ret;
+
+       ret = vidioc_try_fmt_vid_cap(file, priv, f);
+       if (ret)
+               return ret;
+
+       return vidioc_s_fmt(file2ctx(file), f, height);
+}
+
+static int vidioc_s_fmt_vid_out(struct file *file, void *priv,
+                               struct v4l2_format *f)
+{
+       unsigned int height = f->fmt.pix.height;
+       int ret;
+
+       ret = vidioc_try_fmt_vid_out(file, priv, f);
+       if (ret)
+               return ret;
+
+       ret = vidioc_s_fmt(file2ctx(file), f, height);
+       return ret;
+}
+
+static int vidioc_g_selection(struct file *file, void *priv,
+                             struct v4l2_selection *s)
+{
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+       struct bcm2835_codec_q_data *q_data;
+       bool capture_queue = s->type == V4L2_BUF_TYPE_VIDEO_CAPTURE ?
+                                                               true : false;
+
+       if (capture_queue ^ ctx->dev->decode)
+               /* OUTPUT on decoder and CAPTURE on encoder are not valid. */
+               return -EINVAL;
+
+       q_data = get_q_data(ctx, s->type);
+       if (!q_data)
+               return -EINVAL;
+
+       if (ctx->dev->decode) {
+               switch (s->target) {
+               case V4L2_SEL_TGT_COMPOSE_DEFAULT:
+               case V4L2_SEL_TGT_COMPOSE:
+                       s->r.left = 0;
+                       s->r.top = 0;
+                       s->r.width = q_data->crop_width;
+                       s->r.height = q_data->crop_height;
+                       break;
+               case V4L2_SEL_TGT_COMPOSE_BOUNDS:
+                       s->r.left = 0;
+                       s->r.top = 0;
+                       s->r.width = q_data->crop_width;
+                       s->r.height = q_data->crop_height;
+                       break;
+               default:
+                       return -EINVAL;
+               }
+       } else {
+               switch (s->target) {
+               case V4L2_SEL_TGT_CROP_DEFAULT:
+               case V4L2_SEL_TGT_CROP_BOUNDS:
+                       s->r.top = 0;
+                       s->r.left = 0;
+                       s->r.width = q_data->bytesperline;
+                       s->r.height = q_data->height;
+                       break;
+               case V4L2_SEL_TGT_CROP:
+                       s->r.top = 0;
+                       s->r.left = 0;
+                       s->r.width = q_data->crop_width;
+                       s->r.height = q_data->crop_height;
+                       break;
+               default:
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+
+static int vidioc_s_selection(struct file *file, void *priv,
+                             struct v4l2_selection *s)
+{
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+       struct bcm2835_codec_q_data *q_data = NULL;
+       bool capture_queue = s->type == V4L2_BUF_TYPE_VIDEO_CAPTURE ?
+                                                               true : false;
+
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: ctx %p, type %d, q_data %p, target %d, rect x/y %d/%d, w/h %ux%u\n",
+                __func__, ctx, s->type, q_data, s->target, s->r.left, s->r.top,
+                s->r.width, s->r.height);
+
+       if (capture_queue ^ ctx->dev->decode)
+               /* OUTPUT on decoder and CAPTURE on encoder are not valid. */
+               return -EINVAL;
+
+       q_data = get_q_data(ctx, s->type);
+       if (!q_data)
+               return -EINVAL;
+
+       if (ctx->dev->decode) {
+               switch (s->target) {
+               case V4L2_SEL_TGT_COMPOSE:
+                       /* Accept cropped image */
+                       s->r.left = 0;
+                       s->r.top = 0;
+                       s->r.width = min(s->r.width, q_data->crop_width);
+                       s->r.height = min(s->r.height, q_data->height);
+                       q_data->crop_width = s->r.width;
+                       q_data->crop_height = s->r.height;
+                       q_data->selection_set = true;
+                       break;
+               default:
+                       return -EINVAL;
+               }
+       } else {
+               switch (s->target) {
+               case V4L2_SEL_TGT_CROP:
+                       /* Only support crop from (0,0) */
+                       s->r.top = 0;
+                       s->r.left = 0;
+                       s->r.width = min(s->r.width, q_data->crop_width);
+                       s->r.height = min(s->r.height, q_data->crop_height);
+                       q_data->crop_width = s->r.width;
+                       q_data->crop_height = s->r.height;
+                       q_data->selection_set = true;
+                       break;
+               default:
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+
+static int vidioc_subscribe_evt(struct v4l2_fh *fh,
+                               const struct v4l2_event_subscription *sub)
+{
+       switch (sub->type) {
+       case V4L2_EVENT_EOS:
+               return v4l2_event_subscribe(fh, sub, 2, NULL);
+       case V4L2_EVENT_SOURCE_CHANGE:
+               return v4l2_src_change_event_subscribe(fh, sub);
+       default:
+               return v4l2_ctrl_subscribe_event(fh, sub);
+       }
+}
+
+static int bcm2835_codec_set_level_profile(struct bcm2835_codec_ctx *ctx,
+                                          struct v4l2_ctrl *ctrl)
+{
+       struct mmal_parameter_video_profile param;
+       int param_size = sizeof(param);
+       int ret;
+
+       /*
+        * Level and Profile are set via the same MMAL parameter.
+        * Retrieve the current settings and amend the one that has changed.
+        */
+       ret = vchiq_mmal_port_parameter_get(ctx->dev->instance,
+                                           &ctx->component->output[0],
+                                           MMAL_PARAMETER_PROFILE,
+                                           &param,
+                                           &param_size);
+       if (ret)
+               return ret;
+
+       switch (ctrl->id) {
+       case V4L2_CID_MPEG_VIDEO_H264_PROFILE:
+               switch (ctrl->val) {
+               case V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE:
+                       param.profile = MMAL_VIDEO_PROFILE_H264_BASELINE;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE:
+                       param.profile =
+                               MMAL_VIDEO_PROFILE_H264_CONSTRAINED_BASELINE;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_PROFILE_MAIN:
+                       param.profile = MMAL_VIDEO_PROFILE_H264_MAIN;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_PROFILE_HIGH:
+                       param.profile = MMAL_VIDEO_PROFILE_H264_HIGH;
+                       break;
+               default:
+                       /* Should never get here */
+                       break;
+               }
+               break;
+
+       case V4L2_CID_MPEG_VIDEO_H264_LEVEL:
+               switch (ctrl->val) {
+               case V4L2_MPEG_VIDEO_H264_LEVEL_1_0:
+                       param.level = MMAL_VIDEO_LEVEL_H264_1;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_1B:
+                       param.level = MMAL_VIDEO_LEVEL_H264_1b;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_1_1:
+                       param.level = MMAL_VIDEO_LEVEL_H264_11;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_1_2:
+                       param.level = MMAL_VIDEO_LEVEL_H264_12;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_1_3:
+                       param.level = MMAL_VIDEO_LEVEL_H264_13;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_2_0:
+                       param.level = MMAL_VIDEO_LEVEL_H264_2;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_2_1:
+                       param.level = MMAL_VIDEO_LEVEL_H264_21;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_2_2:
+                       param.level = MMAL_VIDEO_LEVEL_H264_22;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_3_0:
+                       param.level = MMAL_VIDEO_LEVEL_H264_3;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_3_1:
+                       param.level = MMAL_VIDEO_LEVEL_H264_31;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_3_2:
+                       param.level = MMAL_VIDEO_LEVEL_H264_32;
+                       break;
+               case V4L2_MPEG_VIDEO_H264_LEVEL_4_0:
+                       param.level = MMAL_VIDEO_LEVEL_H264_4;
+                       break;
+               default:
+                       /* Should never get here */
+                       break;
+               }
+       }
+       ret = vchiq_mmal_port_parameter_set(ctx->dev->instance,
+                                           &ctx->component->output[0],
+                                           MMAL_PARAMETER_PROFILE,
+                                           &param,
+                                           param_size);
+
+       return ret;
+}
+
+static int bcm2835_codec_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+       struct bcm2835_codec_ctx *ctx =
+               container_of(ctrl->handler, struct bcm2835_codec_ctx, hdl);
+       int ret = 0;
+
+       switch (ctrl->id) {
+       case V4L2_CID_MPEG_VIDEO_BITRATE:
+               ctx->bitrate = ctrl->val;
+               if (!ctx->component)
+                       break;
+
+               ret = vchiq_mmal_port_parameter_set(ctx->dev->instance,
+                                                   &ctx->component->output[0],
+                                                   MMAL_PARAMETER_VIDEO_BIT_RATE,
+                                                   &ctrl->val,
+                                                   sizeof(ctrl->val));
+               break;
+
+       case V4L2_CID_MPEG_VIDEO_BITRATE_MODE: {
+               u32 bitrate_mode;
+
+               if (!ctx->component)
+                       break;
+
+               switch (ctrl->val) {
+               default:
+               case V4L2_MPEG_VIDEO_BITRATE_MODE_VBR:
+                       bitrate_mode = MMAL_VIDEO_RATECONTROL_VARIABLE;
+                       break;
+               case V4L2_MPEG_VIDEO_BITRATE_MODE_CBR:
+                       bitrate_mode = MMAL_VIDEO_RATECONTROL_CONSTANT;
+                       break;
+               }
+
+               ret = vchiq_mmal_port_parameter_set(ctx->dev->instance,
+                                                   &ctx->component->output[0],
+                                                   MMAL_PARAMETER_RATECONTROL,
+                                                   &bitrate_mode,
+                                                   sizeof(bitrate_mode));
+               break;
+       }
+       case V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER:
+               if (!ctx->component)
+                       break;
+
+               ret = vchiq_mmal_port_parameter_set(ctx->dev->instance,
+                                                   &ctx->component->output[0],
+                                                   MMAL_PARAMETER_VIDEO_ENCODE_INLINE_HEADER,
+                                                   &ctrl->val,
+                                                   sizeof(ctrl->val));
+               break;
+
+       case V4L2_CID_MPEG_VIDEO_H264_I_PERIOD:
+               if (!ctx->component)
+                       break;
+
+               ret = vchiq_mmal_port_parameter_set(ctx->dev->instance,
+                                                   &ctx->component->output[0],
+                                                   MMAL_PARAMETER_INTRAPERIOD,
+                                                   &ctrl->val,
+                                                   sizeof(ctrl->val));
+               break;
+
+       case V4L2_CID_MPEG_VIDEO_H264_PROFILE:
+       case V4L2_CID_MPEG_VIDEO_H264_LEVEL:
+               if (!ctx->component)
+                       break;
+
+               ret = bcm2835_codec_set_level_profile(ctx, ctrl);
+               break;
+
+       default:
+               v4l2_err(&ctx->dev->v4l2_dev, "Invalid control\n");
+               return -EINVAL;
+       }
+
+       if (ret)
+               v4l2_err(&ctx->dev->v4l2_dev, "Failed setting ctrl %08x, ret %d\n",
+                        ctrl->id, ret);
+       return ret ? -EINVAL : 0;
+}
+
+static const struct v4l2_ctrl_ops bcm2835_codec_ctrl_ops = {
+       .s_ctrl = bcm2835_codec_s_ctrl,
+};
+
+static int vidioc_try_decoder_cmd(struct file *file, void *priv,
+                                 struct v4l2_decoder_cmd *cmd)
+{
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+
+       if (!ctx->dev->decode)
+               return -EINVAL;
+
+       switch (cmd->cmd) {
+       case V4L2_DEC_CMD_STOP:
+               if (cmd->flags & V4L2_DEC_CMD_STOP_TO_BLACK) {
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: DEC cmd->flags=%u stop to black not supported",
+                                __func__, cmd->flags);
+                       return -EINVAL;
+               }
+               break;
+       case V4L2_DEC_CMD_START:
+               break;
+       default:
+               return -EINVAL;
+       }
+       return 0;
+}
+
+static int vidioc_decoder_cmd(struct file *file, void *priv,
+                             struct v4l2_decoder_cmd *cmd)
+{
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+       struct bcm2835_codec_q_data *q_data = &ctx->q_data[V4L2_M2M_SRC];
+       int ret;
+
+       v4l2_dbg(2, debug, &ctx->dev->v4l2_dev, "%s, cmd %u", __func__,
+                cmd->cmd);
+       ret = vidioc_try_decoder_cmd(file, priv, cmd);
+       if (ret)
+               return ret;
+
+       switch (cmd->cmd) {
+       case V4L2_DEC_CMD_STOP:
+               if (q_data->eos_buffer_in_use)
+                       v4l2_err(&ctx->dev->v4l2_dev, "EOS buffers already in use\n");
+               q_data->eos_buffer_in_use = true;
+
+               q_data->eos_buffer.mmal.buffer_size = 0;
+               q_data->eos_buffer.mmal.length = 0;
+               q_data->eos_buffer.mmal.mmal_flags =
+                                               MMAL_BUFFER_HEADER_FLAG_EOS;
+               q_data->eos_buffer.mmal.pts = 0;
+               q_data->eos_buffer.mmal.dts = 0;
+
+               if (!ctx->component)
+                       break;
+
+               ret = vchiq_mmal_submit_buffer(ctx->dev->instance,
+                                              &ctx->component->input[0],
+                                              &q_data->eos_buffer.mmal);
+               if (ret)
+                       v4l2_err(&ctx->dev->v4l2_dev,
+                                "%s: EOS buffer submit failed %d\n",
+                                __func__, ret);
+
+               break;
+
+       case V4L2_DEC_CMD_START:
+               /* Do we need to do anything here? */
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int vidioc_try_encoder_cmd(struct file *file, void *priv,
+                                 struct v4l2_encoder_cmd *cmd)
+{
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+
+       if (ctx->dev->decode)
+               return -EINVAL;
+
+       switch (cmd->cmd) {
+       case V4L2_ENC_CMD_STOP:
+               break;
+
+       case V4L2_ENC_CMD_START:
+               /* Do we need to do anything here? */
+               break;
+       default:
+               return -EINVAL;
+       }
+       return 0;
+}
+
+static int vidioc_encoder_cmd(struct file *file, void *priv,
+                             struct v4l2_encoder_cmd *cmd)
+{
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+       struct bcm2835_codec_q_data *q_data = &ctx->q_data[V4L2_M2M_SRC];
+       int ret;
+
+       v4l2_dbg(2, debug, &ctx->dev->v4l2_dev, "%s, cmd %u", __func__,
+                cmd->cmd);
+       ret = vidioc_try_encoder_cmd(file, priv, cmd);
+       if (ret)
+               return ret;
+
+       switch (cmd->cmd) {
+       case V4L2_ENC_CMD_STOP:
+               if (q_data->eos_buffer_in_use)
+                       v4l2_err(&ctx->dev->v4l2_dev, "EOS buffers already in use\n");
+               q_data->eos_buffer_in_use = true;
+
+               q_data->eos_buffer.mmal.buffer_size = 0;
+               q_data->eos_buffer.mmal.length = 0;
+               q_data->eos_buffer.mmal.mmal_flags =
+                                               MMAL_BUFFER_HEADER_FLAG_EOS;
+               q_data->eos_buffer.mmal.pts = 0;
+               q_data->eos_buffer.mmal.dts = 0;
+
+               if (!ctx->component)
+                       break;
+
+               ret = vchiq_mmal_submit_buffer(ctx->dev->instance,
+                                              &ctx->component->input[0],
+                                              &q_data->eos_buffer.mmal);
+               if (ret)
+                       v4l2_err(&ctx->dev->v4l2_dev,
+                                "%s: EOS buffer submit failed %d\n",
+                                __func__, ret);
+
+               break;
+       case V4L2_ENC_CMD_START:
+               /* Do we need to do anything here? */
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static const struct v4l2_ioctl_ops bcm2835_codec_ioctl_ops = {
+       .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,
+
+       .vidioc_enum_fmt_vid_out = vidioc_enum_fmt_vid_out,
+       .vidioc_g_fmt_vid_out   = vidioc_g_fmt_vid_out,
+       .vidioc_try_fmt_vid_out = vidioc_try_fmt_vid_out,
+       .vidioc_s_fmt_vid_out   = vidioc_s_fmt_vid_out,
+
+       .vidioc_reqbufs         = v4l2_m2m_ioctl_reqbufs,
+       .vidioc_querybuf        = v4l2_m2m_ioctl_querybuf,
+       .vidioc_qbuf            = v4l2_m2m_ioctl_qbuf,
+       .vidioc_dqbuf           = v4l2_m2m_ioctl_dqbuf,
+       .vidioc_prepare_buf     = v4l2_m2m_ioctl_prepare_buf,
+       .vidioc_create_bufs     = v4l2_m2m_ioctl_create_bufs,
+       .vidioc_expbuf          = v4l2_m2m_ioctl_expbuf,
+
+       .vidioc_streamon        = v4l2_m2m_ioctl_streamon,
+       .vidioc_streamoff       = v4l2_m2m_ioctl_streamoff,
+
+       .vidioc_g_selection     = vidioc_g_selection,
+       .vidioc_s_selection     = vidioc_s_selection,
+
+       .vidioc_subscribe_event = vidioc_subscribe_evt,
+       .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+
+       .vidioc_decoder_cmd = vidioc_decoder_cmd,
+       .vidioc_try_decoder_cmd = vidioc_try_decoder_cmd,
+       .vidioc_encoder_cmd = vidioc_encoder_cmd,
+       .vidioc_try_encoder_cmd = vidioc_try_encoder_cmd,
+};
+
+static int bcm2835_codec_set_ctrls(struct bcm2835_codec_ctx *ctx)
+{
+       /*
+        * Query the control handler for the value of the various controls and
+        * set them.
+        */
+       const u32 control_ids[] = {
+               V4L2_CID_MPEG_VIDEO_BITRATE_MODE,
+               V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER,
+               V4L2_CID_MPEG_VIDEO_H264_I_PERIOD,
+               V4L2_CID_MPEG_VIDEO_H264_LEVEL,
+               V4L2_CID_MPEG_VIDEO_H264_PROFILE,
+       };
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(control_ids); i++) {
+               struct v4l2_ctrl *ctrl;
+
+               ctrl = v4l2_ctrl_find(&ctx->hdl, control_ids[i]);
+               if (ctrl)
+                       bcm2835_codec_s_ctrl(ctrl);
+       }
+
+       return 0;
+}
+
+static int bcm2835_codec_create_component(struct bcm2835_codec_ctx *ctx)
+{
+       struct bcm2835_codec_dev *dev = ctx->dev;
+       unsigned int enable = 1;
+       int ret;
+
+       ret = vchiq_mmal_component_init(dev->instance, dev->decode ?
+                                       "ril.video_decode" : "ril.video_encode",
+                                       &ctx->component);
+       if (ret < 0) {
+               v4l2_err(&dev->v4l2_dev, "%s: failed to create component for %s\n",
+                        __func__, dev->decode ? "decode" : "encode");
+               return -ENOMEM;
+       }
+
+       vchiq_mmal_port_parameter_set(dev->instance, &ctx->component->input[0],
+                                     MMAL_PARAMETER_ZERO_COPY, &enable,
+                                     sizeof(enable));
+       vchiq_mmal_port_parameter_set(dev->instance, &ctx->component->output[0],
+                                     MMAL_PARAMETER_ZERO_COPY, &enable,
+                                     sizeof(enable));
+
+       setup_mmal_port_format(ctx, dev->decode, &ctx->q_data[V4L2_M2M_SRC],
+                              &ctx->component->input[0]);
+
+       setup_mmal_port_format(ctx, dev->decode, &ctx->q_data[V4L2_M2M_DST],
+                              &ctx->component->output[0]);
+
+       ret = vchiq_mmal_port_set_format(dev->instance,
+                                        &ctx->component->input[0]);
+       if (ret < 0)
+               goto destroy_component;
+
+       ret = vchiq_mmal_port_set_format(dev->instance,
+                                        &ctx->component->output[0]);
+       if (ret < 0)
+               goto destroy_component;
+
+       if (dev->decode) {
+               if (ctx->q_data[V4L2_M2M_DST].sizeimage <
+                       ctx->component->output[0].minimum_buffer.size)
+                       v4l2_err(&dev->v4l2_dev, "buffer size mismatch sizeimage %u < min size %u\n",
+                                ctx->q_data[V4L2_M2M_DST].sizeimage,
+                                ctx->component->output[0].minimum_buffer.size);
+       } else {
+               if (ctx->q_data[V4L2_M2M_SRC].sizeimage <
+                       ctx->component->output[0].minimum_buffer.size)
+                       v4l2_err(&dev->v4l2_dev, "buffer size mismatch sizeimage %u < min size %u\n",
+                                ctx->q_data[V4L2_M2M_SRC].sizeimage,
+                                ctx->component->output[0].minimum_buffer.size);
+
+               /* Now we have a component we can set all the ctrls */
+               bcm2835_codec_set_ctrls(ctx);
+       }
+
+       return 0;
+
+destroy_component:
+       vchiq_mmal_component_finalise(ctx->dev->instance, ctx->component);
+
+       return ret;
+}
+
+/*
+ * Queue operations
+ */
+
+static int bcm2835_codec_queue_setup(struct vb2_queue *vq,
+                                    unsigned int *nbuffers,
+                                    unsigned int *nplanes,
+                                    unsigned int sizes[],
+                                    struct device *alloc_devs[])
+{
+       struct bcm2835_codec_ctx *ctx = vb2_get_drv_priv(vq);
+       struct bcm2835_codec_q_data *q_data;
+       struct vchiq_mmal_port *port;
+       unsigned int size;
+
+       q_data = get_q_data(ctx, vq->type);
+       if (!q_data)
+               return -EINVAL;
+
+       if (!ctx->component)
+               if (bcm2835_codec_create_component(ctx))
+                       return -EINVAL;
+
+       port = get_port_data(ctx, vq->type);
+
+       size = q_data->sizeimage;
+
+       if (*nplanes)
+               return sizes[0] < size ? -EINVAL : 0;
+
+       *nplanes = 1;
+
+       sizes[0] = size;
+       port->current_buffer.size = size;
+
+       if (*nbuffers < port->minimum_buffer.num)
+               *nbuffers = port->minimum_buffer.num;
+       /* Add one buffer to take an EOS */
+       port->current_buffer.num = *nbuffers + 1;
+
+       return 0;
+}
+
+static int bcm2835_codec_buf_init(struct vb2_buffer *vb)
+{
+       struct bcm2835_codec_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
+       struct vb2_v4l2_buffer *vb2 = to_vb2_v4l2_buffer(vb);
+       struct v4l2_m2m_buffer *m2m = container_of(vb2, struct v4l2_m2m_buffer,
+                                                  vb);
+       struct m2m_mmal_buffer *buf = container_of(m2m, struct m2m_mmal_buffer,
+                                                  m2m);
+
+       v4l2_dbg(2, debug, &ctx->dev->v4l2_dev, "%s: ctx:%p, vb %p\n",
+                __func__, ctx, vb);
+       buf->mmal.buffer = vb2_plane_vaddr(&buf->m2m.vb.vb2_buf, 0);
+       buf->mmal.buffer_size = vb2_plane_size(&buf->m2m.vb.vb2_buf, 0);
+
+       mmal_vchi_buffer_init(ctx->dev->instance, &buf->mmal);
+
+       return 0;
+}
+
+static int bcm2835_codec_buf_prepare(struct vb2_buffer *vb)
+{
+       struct bcm2835_codec_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
+       struct bcm2835_codec_q_data *q_data;
+       struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+       struct v4l2_m2m_buffer *m2m = container_of(vbuf, struct v4l2_m2m_buffer,
+                                                  vb);
+       struct m2m_mmal_buffer *buf = container_of(m2m, struct m2m_mmal_buffer,
+                                                  m2m);
+       int ret;
+
+       v4l2_dbg(4, debug, &ctx->dev->v4l2_dev, "%s: type: %d ptr %p\n",
+                __func__, vb->vb2_queue->type, vb);
+
+       q_data = get_q_data(ctx, vb->vb2_queue->type);
+       if (V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type)) {
+               if (vbuf->field == V4L2_FIELD_ANY)
+                       vbuf->field = V4L2_FIELD_NONE;
+               if (vbuf->field != V4L2_FIELD_NONE) {
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s field isn't supported\n",
+                                __func__);
+                       return -EINVAL;
+               }
+       }
+
+       if (vb2_plane_size(vb, 0) < q_data->sizeimage) {
+               v4l2_err(&ctx->dev->v4l2_dev, "%s data will not fit into plane (%lu < %lu)\n",
+                        __func__, vb2_plane_size(vb, 0),
+                        (long)q_data->sizeimage);
+               return -EINVAL;
+       }
+
+       if (!V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type))
+               vb2_set_plane_payload(vb, 0, q_data->sizeimage);
+
+       /*
+        * We want to do this at init, but vb2_core_expbuf checks that the
+        * index < q->num_buffers, and q->num_buffers only gets updated once
+        * all the buffers are allocated.
+        */
+       if (!buf->mmal.dma_buf) {
+               ret = vb2_core_expbuf_dmabuf(vb->vb2_queue,
+                                            vb->vb2_queue->type, vb->index, 0,
+                                            O_CLOEXEC, &buf->mmal.dma_buf);
+               if (ret)
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed to expbuf idx %d, ret %d\n",
+                                __func__, vb->index, ret);
+       } else {
+               ret = 0;
+       }
+
+       return ret;
+}
+
+static void bcm2835_codec_buf_queue(struct vb2_buffer *vb)
+{
+       struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+       struct bcm2835_codec_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
+
+       v4l2_dbg(4, debug, &ctx->dev->v4l2_dev, "%s: type: %d ptr %p vbuf->flags %u, seq %u, bytesused %u\n",
+                __func__, vb->vb2_queue->type, vb, vbuf->flags, vbuf->sequence,
+                vb->planes[0].bytesused);
+       v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf);
+}
+
+static void bcm2835_codec_buffer_cleanup(struct vb2_buffer *vb)
+{
+       struct bcm2835_codec_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
+       struct vb2_v4l2_buffer *vb2 = to_vb2_v4l2_buffer(vb);
+       struct v4l2_m2m_buffer *m2m = container_of(vb2, struct v4l2_m2m_buffer,
+                                                  vb);
+       struct m2m_mmal_buffer *buf = container_of(m2m, struct m2m_mmal_buffer,
+                                                  m2m);
+
+       v4l2_dbg(2, debug, &ctx->dev->v4l2_dev, "%s: ctx:%p, vb %p\n",
+                __func__, ctx, vb);
+
+       mmal_vchi_buffer_cleanup(&buf->mmal);
+
+       if (buf->mmal.dma_buf) {
+               dma_buf_put(buf->mmal.dma_buf);
+               buf->mmal.dma_buf = NULL;
+       }
+}
+
+static int bcm2835_codec_start_streaming(struct vb2_queue *q,
+                                        unsigned int count)
+{
+       struct bcm2835_codec_ctx *ctx = vb2_get_drv_priv(q);
+       struct bcm2835_codec_dev *dev = ctx->dev;
+       struct bcm2835_codec_q_data *q_data = get_q_data(ctx, q->type);
+       int ret;
+
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: type: %d count %d\n",
+                __func__, q->type, count);
+       q_data->sequence = 0;
+
+       if (!ctx->component_enabled) {
+               ret = vchiq_mmal_component_enable(dev->instance,
+                                                 ctx->component);
+               if (ret)
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed enabling component, ret %d\n",
+                                __func__, ret);
+               ctx->component_enabled = true;
+       }
+
+       if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) {
+               /*
+                * Create the EOS buffer.
+                * We only need the MMAL part, and want to NOT attach a memory
+                * buffer to it as it should only take flags.
+                */
+               memset(&q_data->eos_buffer, 0, sizeof(q_data->eos_buffer));
+               mmal_vchi_buffer_init(dev->instance,
+                                     &q_data->eos_buffer.mmal);
+               q_data->eos_buffer_in_use = false;
+
+               ctx->component->input[0].cb_ctx = ctx;
+               ret = vchiq_mmal_port_enable(dev->instance,
+                                            &ctx->component->input[0],
+                                            ip_buffer_cb);
+               if (ret)
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed enabling i/p port, ret %d\n",
+                                __func__, ret);
+       } else {
+               ctx->component->output[0].cb_ctx = ctx;
+               ret = vchiq_mmal_port_enable(dev->instance,
+                                            &ctx->component->output[0],
+                                            op_buffer_cb);
+               if (ret)
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed enabling o/p port, ret %d\n",
+                                __func__, ret);
+       }
+       return ret;
+}
+
+static void bcm2835_codec_stop_streaming(struct vb2_queue *q)
+{
+       struct bcm2835_codec_ctx *ctx = vb2_get_drv_priv(q);
+       struct bcm2835_codec_dev *dev = ctx->dev;
+       struct bcm2835_codec_q_data *q_data = get_q_data(ctx, q->type);
+       struct vchiq_mmal_port *port = get_port_data(ctx, q->type);
+       struct vb2_v4l2_buffer *vbuf;
+       struct vb2_v4l2_buffer *vb2;
+       struct v4l2_m2m_buffer *m2m;
+       struct m2m_mmal_buffer *buf;
+       int ret, i;
+
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: type: %d - return buffers\n",
+                __func__, q->type);
+
+       init_completion(&ctx->frame_cmplt);
+
+       /* Clear out all buffers held by m2m framework */
+       for (;;) {
+               if (V4L2_TYPE_IS_OUTPUT(q->type))
+                       vbuf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
+               else
+                       vbuf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
+               if (!vbuf)
+                       break;
+               v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: return buffer %p\n",
+                        __func__, vbuf);
+
+               v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
+       }
+
+       /* Disable MMAL port - this will flush buffers back */
+       ret = vchiq_mmal_port_disable(dev->instance, port);
+       if (ret)
+               v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed disabling %s port, ret %d\n",
+                        __func__, V4L2_TYPE_IS_OUTPUT(q->type) ? "i/p" : "o/p",
+                        ret);
+
+       while (atomic_read(&port->buffers_with_vpu)) {
+               v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: Waiting for buffers to be returned - %d outstanding\n",
+                        __func__, atomic_read(&port->buffers_with_vpu));
+               ret = wait_for_completion_timeout(&ctx->frame_cmplt, HZ);
+               if (ret <= 0) {
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Timeout waiting for buffers to be returned - %d outstanding\n",
+                                __func__,
+                                atomic_read(&port->buffers_with_vpu));
+                       break;
+               }
+       }
+
+       /*
+        * Release the VCSM handle here as otherwise REQBUFS(0) aborts because
+        * someone is using the dmabuf before giving the driver a chance to do
+        * anything about it.
+        */
+       for (i = 0; i < q->num_buffers; i++) {
+               vb2 = to_vb2_v4l2_buffer(q->bufs[i]);
+               m2m = container_of(vb2, struct v4l2_m2m_buffer, vb);
+               buf = container_of(m2m, struct m2m_mmal_buffer, m2m);
+
+               mmal_vchi_buffer_cleanup(&buf->mmal);
+               if (buf->mmal.dma_buf) {
+                       dma_buf_put(buf->mmal.dma_buf);
+                       buf->mmal.dma_buf = NULL;
+               }
+       }
+
+       /* If both ports disabled, then disable the component */
+       if (!ctx->component->input[0].enabled &&
+           !ctx->component->output[0].enabled) {
+               ret = vchiq_mmal_component_disable(dev->instance,
+                                                  ctx->component);
+               if (ret)
+                       v4l2_err(&ctx->dev->v4l2_dev, "%s: Failed enabling component, ret %d\n",
+                                __func__, ret);
+       }
+
+       if (V4L2_TYPE_IS_OUTPUT(q->type))
+               mmal_vchi_buffer_cleanup(&q_data->eos_buffer.mmal);
+
+       v4l2_dbg(1, debug, &ctx->dev->v4l2_dev, "%s: done\n", __func__);
+}
+
+static const struct vb2_ops bcm2835_codec_qops = {
+       .queue_setup     = bcm2835_codec_queue_setup,
+       .buf_init        = bcm2835_codec_buf_init,
+       .buf_prepare     = bcm2835_codec_buf_prepare,
+       .buf_queue       = bcm2835_codec_buf_queue,
+       .buf_cleanup     = bcm2835_codec_buffer_cleanup,
+       .start_streaming = bcm2835_codec_start_streaming,
+       .stop_streaming  = bcm2835_codec_stop_streaming,
+       .wait_prepare    = vb2_ops_wait_prepare,
+       .wait_finish     = vb2_ops_wait_finish,
+};
+
+static int queue_init(void *priv, struct vb2_queue *src_vq,
+                     struct vb2_queue *dst_vq)
+{
+       struct bcm2835_codec_ctx *ctx = priv;
+       int ret;
+
+       src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
+       src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
+       src_vq->drv_priv = ctx;
+       src_vq->buf_struct_size = sizeof(struct m2m_mmal_buffer);
+       src_vq->ops = &bcm2835_codec_qops;
+       src_vq->mem_ops = &vb2_dma_contig_memops;
+       src_vq->dev = &ctx->dev->pdev->dev;
+       src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
+       src_vq->lock = &ctx->dev->dev_mutex;
+
+       ret = vb2_queue_init(src_vq);
+       if (ret)
+               return ret;
+
+       dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+       dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
+       dst_vq->drv_priv = ctx;
+       dst_vq->buf_struct_size = sizeof(struct m2m_mmal_buffer);
+       dst_vq->ops = &bcm2835_codec_qops;
+       dst_vq->mem_ops = &vb2_dma_contig_memops;
+       dst_vq->dev = &ctx->dev->pdev->dev;
+       dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
+       dst_vq->lock = &ctx->dev->dev_mutex;
+
+       return vb2_queue_init(dst_vq);
+}
+
+/*
+ * File operations
+ */
+static int bcm2835_codec_open(struct file *file)
+{
+       struct bcm2835_codec_dev *dev = video_drvdata(file);
+       struct bcm2835_codec_ctx *ctx = NULL;
+       struct v4l2_ctrl_handler *hdl;
+       int rc = 0;
+
+       v4l2_dbg(1, debug, &dev->v4l2_dev, "Creating instance for %s\n",
+                dev->decode ? "decode" : "encode");
+       if (mutex_lock_interruptible(&dev->dev_mutex)) {
+               v4l2_err(&dev->v4l2_dev, "Mutex fail\n");
+               return -ERESTARTSYS;
+       }
+       ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+       if (!ctx) {
+               rc = -ENOMEM;
+               goto open_unlock;
+       }
+
+       ctx->q_data[V4L2_M2M_SRC].fmt = get_default_format(dev->decode, false);
+       ctx->q_data[V4L2_M2M_DST].fmt = get_default_format(dev->decode, true);
+       if (dev->decode) {
+               /*
+                * Input width and height are irrelevant as they will be defined
+                * by the bitstream not the format. Required by V4L2 though.
+                */
+               ctx->q_data[V4L2_M2M_SRC].crop_width = DEFAULT_WIDTH;
+               ctx->q_data[V4L2_M2M_SRC].crop_height = DEFAULT_HEIGHT;
+               ctx->q_data[V4L2_M2M_SRC].height = DEFAULT_HEIGHT;
+               ctx->q_data[V4L2_M2M_SRC].bytesperline = 0;
+               ctx->q_data[V4L2_M2M_SRC].sizeimage =
+                                               DEF_COMP_BUF_SIZE_720P_OR_LESS;
+
+               ctx->q_data[V4L2_M2M_DST].crop_width = DEFAULT_WIDTH;
+               ctx->q_data[V4L2_M2M_DST].crop_height = DEFAULT_HEIGHT;
+               ctx->q_data[V4L2_M2M_DST].height = DEFAULT_HEIGHT;
+               ctx->q_data[V4L2_M2M_DST].bytesperline =
+                               get_bytesperline(DEFAULT_WIDTH,
+                                                ctx->q_data[V4L2_M2M_DST].fmt);
+               ctx->q_data[V4L2_M2M_DST].sizeimage =
+                       get_sizeimage(ctx->q_data[V4L2_M2M_DST].bytesperline,
+                                     ctx->q_data[V4L2_M2M_DST].height,
+                                     ctx->q_data[V4L2_M2M_DST].fmt);
+       } else {
+               ctx->q_data[V4L2_M2M_SRC].crop_width = DEFAULT_WIDTH;
+               ctx->q_data[V4L2_M2M_SRC].crop_height = DEFAULT_HEIGHT;
+               ctx->q_data[V4L2_M2M_SRC].height = DEFAULT_HEIGHT;
+               ctx->q_data[V4L2_M2M_SRC].bytesperline =
+                               get_bytesperline(DEFAULT_WIDTH,
+                                                ctx->q_data[V4L2_M2M_SRC].fmt);
+               ctx->q_data[V4L2_M2M_SRC].sizeimage =
+                       get_sizeimage(ctx->q_data[V4L2_M2M_SRC].bytesperline,
+                                     ctx->q_data[V4L2_M2M_SRC].height,
+                                     ctx->q_data[V4L2_M2M_SRC].fmt);
+
+               ctx->q_data[V4L2_M2M_DST].crop_width = DEFAULT_WIDTH;
+               ctx->q_data[V4L2_M2M_DST].crop_height = DEFAULT_HEIGHT;
+               ctx->q_data[V4L2_M2M_DST].bytesperline = 0;
+               ctx->q_data[V4L2_M2M_DST].height = DEFAULT_HEIGHT;
+               ctx->q_data[V4L2_M2M_DST].sizeimage =
+                                               DEF_COMP_BUF_SIZE_720P_OR_LESS;
+       }
+
+       ctx->colorspace = V4L2_COLORSPACE_REC709;
+       ctx->bitrate = 10 * 1000 * 1000;
+
+       /* Initialise V4L2 contexts */
+       v4l2_fh_init(&ctx->fh, video_devdata(file));
+       file->private_data = &ctx->fh;
+       ctx->dev = dev;
+       hdl = &ctx->hdl;
+       if (!dev->decode) {
+               /* Encode controls */
+               v4l2_ctrl_handler_init(hdl, 6);
+
+               v4l2_ctrl_new_std_menu(hdl, &bcm2835_codec_ctrl_ops,
+                                      V4L2_CID_MPEG_VIDEO_BITRATE_MODE,
+                                      V4L2_MPEG_VIDEO_BITRATE_MODE_CBR, 0,
+                                      V4L2_MPEG_VIDEO_BITRATE_MODE_VBR);
+               v4l2_ctrl_new_std(hdl, &bcm2835_codec_ctrl_ops,
+                                 V4L2_CID_MPEG_VIDEO_BITRATE,
+                                 25 * 1000, 25 * 1000 * 1000,
+                                 25 * 1000, 10 * 1000 * 1000);
+               v4l2_ctrl_new_std(hdl, &bcm2835_codec_ctrl_ops,
+                                 V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER,
+                                 0, 1,
+                                 1, 0);
+               v4l2_ctrl_new_std(hdl, &bcm2835_codec_ctrl_ops,
+                                 V4L2_CID_MPEG_VIDEO_H264_I_PERIOD,
+                                 0, 0x7FFFFFFF,
+                                 1, 60);
+               v4l2_ctrl_new_std_menu(hdl, &bcm2835_codec_ctrl_ops,
+                                      V4L2_CID_MPEG_VIDEO_H264_LEVEL,
+                                      V4L2_MPEG_VIDEO_H264_LEVEL_4_2,
+                                      ~(BIT(V4L2_MPEG_VIDEO_H264_LEVEL_1_0) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_1B) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_1_1) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_1_2) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_1_3) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_2_0) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_2_1) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_2_2) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_3_0) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_3_1) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_3_2) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_4_0) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_4_1) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_LEVEL_4_2)),
+                                      V4L2_MPEG_VIDEO_H264_LEVEL_4_0);
+               v4l2_ctrl_new_std_menu(hdl, &bcm2835_codec_ctrl_ops,
+                                      V4L2_CID_MPEG_VIDEO_H264_PROFILE,
+                                      V4L2_MPEG_VIDEO_H264_PROFILE_HIGH,
+                                      ~(BIT(V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_PROFILE_MAIN) |
+                                        BIT(V4L2_MPEG_VIDEO_H264_PROFILE_HIGH)),
+                                       V4L2_MPEG_VIDEO_H264_PROFILE_HIGH);
+               if (hdl->error) {
+                       rc = hdl->error;
+                       goto free_ctrl_handler;
+               }
+               ctx->fh.ctrl_handler = hdl;
+               v4l2_ctrl_handler_setup(hdl);
+       }
+
+       ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx, &queue_init);
+
+       if (IS_ERR(ctx->fh.m2m_ctx)) {
+               rc = PTR_ERR(ctx->fh.m2m_ctx);
+
+               goto free_ctrl_handler;
+       }
+
+       /* Set both queues as buffered as we have buffering in the VPU. That
+        * means that we will be scheduled whenever either an input or output
+        * buffer is available (otherwise one of each are required).
+        */
+       v4l2_m2m_set_src_buffered(ctx->fh.m2m_ctx, true);
+       v4l2_m2m_set_dst_buffered(ctx->fh.m2m_ctx, true);
+
+       v4l2_fh_add(&ctx->fh);
+       atomic_inc(&dev->num_inst);
+
+       mutex_unlock(&dev->dev_mutex);
+       return 0;
+
+free_ctrl_handler:
+       v4l2_ctrl_handler_free(hdl);
+       kfree(ctx);
+open_unlock:
+       mutex_unlock(&dev->dev_mutex);
+       return rc;
+}
+
+static int bcm2835_codec_release(struct file *file)
+{
+       struct bcm2835_codec_dev *dev = video_drvdata(file);
+       struct bcm2835_codec_ctx *ctx = file2ctx(file);
+
+       v4l2_dbg(1, debug, &dev->v4l2_dev, "%s: Releasing instance %p\n",
+                __func__, ctx);
+
+       v4l2_fh_del(&ctx->fh);
+       v4l2_fh_exit(&ctx->fh);
+       v4l2_ctrl_handler_free(&ctx->hdl);
+       mutex_lock(&dev->dev_mutex);
+       v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
+
+       if (ctx->component)
+               vchiq_mmal_component_finalise(dev->instance, ctx->component);
+
+       mutex_unlock(&dev->dev_mutex);
+       kfree(ctx);
+
+       atomic_dec(&dev->num_inst);
+
+       return 0;
+}
+
+static const struct v4l2_file_operations bcm2835_codec_fops = {
+       .owner          = THIS_MODULE,
+       .open           = bcm2835_codec_open,
+       .release        = bcm2835_codec_release,
+       .poll           = v4l2_m2m_fop_poll,
+       .unlocked_ioctl = video_ioctl2,
+       .mmap           = v4l2_m2m_fop_mmap,
+};
+
+static const struct video_device bcm2835_codec_videodev = {
+       .name           = MEM2MEM_NAME,
+       .vfl_dir        = VFL_DIR_M2M,
+       .fops           = &bcm2835_codec_fops,
+       .ioctl_ops      = &bcm2835_codec_ioctl_ops,
+       .minor          = -1,
+       .release        = video_device_release_empty,
+};
+
+static const struct v4l2_m2m_ops m2m_ops = {
+       .device_run     = device_run,
+       .job_ready      = job_ready,
+       .job_abort      = job_abort,
+};
+
+static int bcm2835_codec_create(struct platform_device *pdev,
+                               struct bcm2835_codec_dev **new_dev,
+                               bool decode)
+{
+       struct bcm2835_codec_dev *dev;
+       struct video_device *vfd;
+       struct vchiq_mmal_instance *instance = NULL;
+       int video_nr;
+       int ret;
+
+       dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+       if (!dev)
+               return -ENOMEM;
+
+       dev->pdev = pdev;
+
+       dev->decode = decode;
+
+       ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
+       if (ret)
+               return ret;
+
+       atomic_set(&dev->num_inst, 0);
+       mutex_init(&dev->dev_mutex);
+
+       dev->vfd = bcm2835_codec_videodev;
+       vfd = &dev->vfd;
+       vfd->lock = &dev->dev_mutex;
+       vfd->v4l2_dev = &dev->v4l2_dev;
+
+       if (dev->decode) {
+               v4l2_disable_ioctl(vfd, VIDIOC_ENCODER_CMD);
+               v4l2_disable_ioctl(vfd, VIDIOC_TRY_ENCODER_CMD);
+               video_nr = decode_video_nr;
+       } else {
+               v4l2_disable_ioctl(vfd, VIDIOC_DECODER_CMD);
+               v4l2_disable_ioctl(vfd, VIDIOC_TRY_DECODER_CMD);
+               video_nr = encode_video_nr;
+       }
+
+       ret = video_register_device(vfd, VFL_TYPE_GRABBER, video_nr);
+       if (ret) {
+               v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");
+               goto unreg_dev;
+       }
+
+       video_set_drvdata(vfd, dev);
+       snprintf(vfd->name, sizeof(vfd->name), "%s",
+                bcm2835_codec_videodev.name);
+       v4l2_info(&dev->v4l2_dev, "Device registered as /dev/video%d\n",
+                 vfd->num);
+
+       *new_dev = dev;
+
+       dev->m2m_dev = v4l2_m2m_init(&m2m_ops);
+       if (IS_ERR(dev->m2m_dev)) {
+               v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem device\n");
+               ret = PTR_ERR(dev->m2m_dev);
+               goto err_m2m;
+       }
+
+       ret = vchiq_mmal_init(&instance);
+       if (ret < 0)
+               goto err_m2m;
+       dev->instance = instance;
+
+       v4l2_info(&dev->v4l2_dev, "Loaded V4L2 %s codec\n",
+                 dev->decode ? "decode" : "encode");
+       return 0;
+
+err_m2m:
+       v4l2_m2m_release(dev->m2m_dev);
+       video_unregister_device(&dev->vfd);
+unreg_dev:
+       v4l2_device_unregister(&dev->v4l2_dev);
+
+       return ret;
+}
+
+static int bcm2835_codec_destroy(struct bcm2835_codec_dev *dev)
+{
+       if (!dev)
+               return -ENODEV;
+
+       v4l2_info(&dev->v4l2_dev, "Removing " MEM2MEM_NAME);
+       v4l2_m2m_release(dev->m2m_dev);
+       video_unregister_device(&dev->vfd);
+       v4l2_device_unregister(&dev->v4l2_dev);
+
+       return 0;
+}
+
+static int bcm2835_codec_probe(struct platform_device *pdev)
+{
+       struct bcm2835_codec_driver *drv;
+       int ret = 0;
+
+       drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
+       if (!drv)
+               return -ENOMEM;
+
+       ret = bcm2835_codec_create(pdev, &drv->encode, false);
+       if (ret)
+               goto out;
+
+       ret = bcm2835_codec_create(pdev, &drv->decode, true);
+       if (ret)
+               goto out;
+
+       platform_set_drvdata(pdev, drv);
+
+       return 0;
+
+out:
+       if (drv->encode) {
+               bcm2835_codec_destroy(drv->encode);
+               drv->encode = NULL;
+       }
+       return ret;
+}
+
+static int bcm2835_codec_remove(struct platform_device *pdev)
+{
+       struct bcm2835_codec_driver *drv = platform_get_drvdata(pdev);
+
+       bcm2835_codec_destroy(drv->encode);
+
+       bcm2835_codec_destroy(drv->decode);
+
+       return 0;
+}
+
+static struct platform_driver bcm2835_v4l2_codec_driver = {
+       .probe = bcm2835_codec_probe,
+       .remove = bcm2835_codec_remove,
+       .driver = {
+                  .name = "bcm2835-codec",
+                  .owner = THIS_MODULE,
+                  },
+};
+
+module_platform_driver(bcm2835_v4l2_codec_driver);
+
+MODULE_DESCRIPTION("BCM2835 codec V4L2 driver");
+MODULE_AUTHOR("Dave Stevenson, <dave.stevenson@raspberrypi.org>");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.0.1");
+MODULE_ALIAS("platform:bcm2835-codec");