// SPDX-License-Identifier: GPL-2.0
/*
 * camss-video.c
 *
 * Qualcomm MSM Camera Subsystem - V4L2 device node
 *
 * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
 * Copyright (C) 2015-2018 Linaro Ltd.
 */
#include <linux/slab.h>
#include <media/media-entity.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mc.h>
#include <media/videobuf2-dma-sg.h>

#include "camss-video.h"
#include "camss.h"

#define CAMSS_FRAME_MIN_WIDTH           1
#define CAMSS_FRAME_MAX_WIDTH           8191
#define CAMSS_FRAME_MIN_HEIGHT          1
#define CAMSS_FRAME_MAX_HEIGHT_RDI      8191
#define CAMSS_FRAME_MAX_HEIGHT_PIX      4096

/* -----------------------------------------------------------------------------
 * Helper functions
 */

/*
 * video_mbus_to_pix_mp - Convert v4l2_mbus_framefmt to v4l2_pix_format_mplane
 * @mbus: v4l2_mbus_framefmt format (input)
 * @pix: v4l2_pix_format_mplane format (output)
 * @f: a pointer to formats array element to be used for the conversion
 * @alignment: bytesperline alignment value
 *
 * Fill the output pix structure with information from the input mbus format.
 *
 * Return 0 on success or a negative error code otherwise
 */
static int video_mbus_to_pix_mp(const struct v4l2_mbus_framefmt *mbus,
                                struct v4l2_pix_format_mplane *pix,
                                const struct camss_format_info *f,
                                unsigned int alignment)
{
        unsigned int i;
        u32 bytesperline;

        if (!alignment)
                alignment = camss_format_get_bpl_alignment(f);

        memset(pix, 0, sizeof(*pix));
        v4l2_fill_pix_format_mplane(pix, mbus);
        pix->pixelformat = f->pixelformat;
        pix->num_planes = f->planes;
        for (i = 0; i < pix->num_planes; i++) {
                bytesperline = pix->width / f->hsub[i].numerator *
                        f->hsub[i].denominator * f->bpp[i] / 8;
                bytesperline = roundup(bytesperline, alignment);
                pix->plane_fmt[i].bytesperline = bytesperline;
                pix->plane_fmt[i].sizeimage = pix->height /
                                f->vsub[i].numerator * f->vsub[i].denominator *
                                bytesperline;
        }

        return 0;
}

static struct v4l2_subdev *video_remote_subdev(struct camss_video *video,
                                               u32 *pad)
{
        struct media_pad *remote;

        remote = media_pad_remote_pad_first(&video->pad);

        if (!remote || !is_media_entity_v4l2_subdev(remote->entity))
                return NULL;

        if (pad)
                *pad = remote->index;

        return media_entity_to_v4l2_subdev(remote->entity);
}

static int video_get_subdev_format(struct camss_video *video,
                                   struct v4l2_format *format)
{
        struct v4l2_subdev_format fmt = {
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        struct v4l2_subdev *subdev;
        u32 pad;
        int ret;

        subdev = video_remote_subdev(video, &pad);
        if (subdev == NULL)
                return -EPIPE;

        fmt.pad = pad;

        ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
        if (ret)
                return ret;

        ret = camss_format_find_format(fmt.format.code, format->fmt.pix_mp.pixelformat,
                                       video->formats, video->nformats);
        if (ret < 0)
                return ret;

        format->type = video->type;

        return video_mbus_to_pix_mp(&fmt.format, &format->fmt.pix_mp,
                                    &video->formats[ret], video->bpl_alignment);
}

/* -----------------------------------------------------------------------------
 * Video queue operations
 */

static int video_queue_setup(struct vb2_queue *q,
        unsigned int *num_buffers, unsigned int *num_planes,
        unsigned int sizes[], struct device *alloc_devs[])
{
        struct camss_video *video = vb2_get_drv_priv(q);
        const struct v4l2_pix_format_mplane *format =
                                                &video->active_fmt.fmt.pix_mp;
        unsigned int i;

        if (*num_planes) {
                if (*num_planes != format->num_planes)
                        return -EINVAL;

                for (i = 0; i < *num_planes; i++)
                        if (sizes[i] < format->plane_fmt[i].sizeimage)
                                return -EINVAL;

                return 0;
        }

        *num_planes = format->num_planes;

        for (i = 0; i < *num_planes; i++)
                sizes[i] = format->plane_fmt[i].sizeimage;

        return 0;
}

static int video_buf_init(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct camss_video *video = vb2_get_drv_priv(vb->vb2_queue);
        struct camss_buffer *buffer = container_of(vbuf, struct camss_buffer,
                                                   vb);
        const struct v4l2_pix_format_mplane *format =
                                                &video->active_fmt.fmt.pix_mp;
        struct sg_table *sgt;
        unsigned int i;

        for (i = 0; i < format->num_planes; i++) {
                sgt = vb2_dma_sg_plane_desc(vb, i);
                if (!sgt)
                        return -EFAULT;

                buffer->addr[i] = sg_dma_address(sgt->sgl);
        }

        if (format->pixelformat == V4L2_PIX_FMT_NV12 ||
                        format->pixelformat == V4L2_PIX_FMT_NV21 ||
                        format->pixelformat == V4L2_PIX_FMT_NV16 ||
                        format->pixelformat == V4L2_PIX_FMT_NV61)
                buffer->addr[1] = buffer->addr[0] +
                                format->plane_fmt[0].bytesperline *
                                format->height;

        return 0;
}

static int video_buf_prepare(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct camss_video *video = vb2_get_drv_priv(vb->vb2_queue);
        const struct v4l2_pix_format_mplane *format =
                                                &video->active_fmt.fmt.pix_mp;
        unsigned int i;

        for (i = 0; i < format->num_planes; i++) {
                if (format->plane_fmt[i].sizeimage > vb2_plane_size(vb, i))
                        return -EINVAL;

                vb2_set_plane_payload(vb, i, format->plane_fmt[i].sizeimage);
        }

        vbuf->field = V4L2_FIELD_NONE;

        return 0;
}

static void video_buf_queue(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct camss_video *video = vb2_get_drv_priv(vb->vb2_queue);
        struct camss_buffer *buffer = container_of(vbuf, struct camss_buffer,
                                                   vb);

        video->ops->queue_buffer(video, buffer);
}

static int video_check_format(struct camss_video *video)
{
        struct v4l2_pix_format_mplane *pix = &video->active_fmt.fmt.pix_mp;
        struct v4l2_format format;
        struct v4l2_pix_format_mplane *sd_pix = &format.fmt.pix_mp;
        int ret;

        sd_pix->pixelformat = pix->pixelformat;
        ret = video_get_subdev_format(video, &format);
        if (ret < 0)
                return ret;

        dev_dbg(video->camss->dev,
                "%s: format is (%ux%u %p4cc/%up field:%u), trying (%ux%u %p4cc/%up field:%u)",
                 video->vdev.name, sd_pix->width, sd_pix->height, &sd_pix->pixelformat,
                 sd_pix->num_planes, sd_pix->field, pix->width, pix->height, &pix->pixelformat,
                 pix->num_planes, pix->field);

        if (pix->pixelformat != sd_pix->pixelformat ||
            pix->height != sd_pix->height ||
            pix->width != sd_pix->width ||
            pix->num_planes != sd_pix->num_planes ||
            pix->field != format.fmt.pix_mp.field)
                return -EPIPE;

        return 0;
}

static int video_prepare_streaming(struct vb2_queue *q)
{
        struct camss_video *video = vb2_get_drv_priv(q);
        struct video_device *vdev = &video->vdev;
        int ret;

        ret = v4l2_pipeline_pm_get(&vdev->entity);
        if (ret < 0) {
                dev_err(video->camss->dev, "Failed to power up pipeline: %d\n",
                        ret);
        }

        return ret;
}

static int video_start_streaming(struct vb2_queue *q, unsigned int count)
{
        struct camss_video *video = vb2_get_drv_priv(q);
        struct video_device *vdev = &video->vdev;
        struct media_entity *entity;
        struct media_pad *pad;
        struct v4l2_subdev *subdev;
        int ret;

        ret = video_device_pipeline_alloc_start(vdev);
        if (ret < 0) {
                dev_err(video->camss->dev, "Failed to start media pipeline: %d\n", ret);
                goto flush_buffers;
        }

        ret = video_check_format(video);
        if (ret < 0)
                goto error;

        entity = &vdev->entity;
        while (1) {
                pad = &entity->pads[0];
                if (!(pad->flags & MEDIA_PAD_FL_SINK))
                        break;

                pad = media_pad_remote_pad_first(pad);
                if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
                        break;

                entity = pad->entity;
                subdev = media_entity_to_v4l2_subdev(entity);

                ret = v4l2_subdev_call(subdev, video, s_stream, 1);
                if (ret < 0 && ret != -ENOIOCTLCMD)
                        goto error;
        }

        return 0;

error:
        video_device_pipeline_stop(vdev);

flush_buffers:
        video->ops->flush_buffers(video, VB2_BUF_STATE_QUEUED);

        return ret;
}

static void video_stop_streaming(struct vb2_queue *q)
{
        struct camss_video *video = vb2_get_drv_priv(q);
        struct video_device *vdev = &video->vdev;
        struct media_entity *entity;
        struct media_pad *pad;
        struct v4l2_subdev *subdev;
        int ret;

        entity = &vdev->entity;
        while (1) {
                pad = &entity->pads[0];
                if (!(pad->flags & MEDIA_PAD_FL_SINK))
                        break;

                pad = media_pad_remote_pad_first(pad);
                if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
                        break;

                entity = pad->entity;
                subdev = media_entity_to_v4l2_subdev(entity);

                ret = v4l2_subdev_call(subdev, video, s_stream, 0);

                if (ret) {
                        dev_err(video->camss->dev, "Video pipeline stop failed: %d\n", ret);
                        return;
                }
        }

        video_device_pipeline_stop(vdev);

        video->ops->flush_buffers(video, VB2_BUF_STATE_ERROR);
}

static void video_unprepare_streaming(struct vb2_queue *q)
{
        struct camss_video *video = vb2_get_drv_priv(q);
        struct video_device *vdev = &video->vdev;

        v4l2_pipeline_pm_put(&vdev->entity);
}

static const struct vb2_ops msm_video_vb2_q_ops = {
        .queue_setup     = video_queue_setup,
        .buf_init        = video_buf_init,
        .buf_prepare     = video_buf_prepare,
        .buf_queue       = video_buf_queue,
        .prepare_streaming = video_prepare_streaming,
        .start_streaming = video_start_streaming,
        .stop_streaming  = video_stop_streaming,
        .unprepare_streaming = video_unprepare_streaming,
};

/* -----------------------------------------------------------------------------
 * V4L2 ioctls
 */

static int video_querycap(struct file *file, void *fh,
                          struct v4l2_capability *cap)
{
        strscpy(cap->driver, "qcom-camss", sizeof(cap->driver));
        strscpy(cap->card, "Qualcomm Camera Subsystem", sizeof(cap->card));

        return 0;
}

static int video_enum_fmt(struct file *file, void *fh, struct v4l2_fmtdesc *f)
{
        struct camss_video *video = video_drvdata(file);
        int i, j, k;
        u32 mcode = f->mbus_code;

        if (f->type != video->type)
                return -EINVAL;

        if (f->index >= video->nformats)
                return -EINVAL;

        /*
         * Find index "i" of "k"th unique pixelformat in formats array.
         *
         * If f->mbus_code passed to video_enum_fmt() is not zero, a device
         * with V4L2_CAP_IO_MC capability restricts enumeration to only the
         * pixel formats that can be produced from that media bus code.
         * This is implemented by skipping video->formats[] entries with
         * code != f->mbus_code (if f->mbus_code is not zero).
         * If the f->mbus_code passed to video_enum_fmt() is not supported,
         * -EINVAL is returned.
         * If f->mbus_code is zero, all the pixel formats are enumerated.
         */
        k = -1;
        for (i = 0; i < video->nformats; i++) {
                if (mcode != 0 && video->formats[i].code != mcode)
                        continue;

                for (j = 0; j < i; j++) {
                        if (mcode != 0 && video->formats[j].code != mcode)
                                continue;
                        if (video->formats[i].pixelformat ==
                                        video->formats[j].pixelformat)
                                break;
                }

                if (j == i)
                        k++;

                if (k == f->index)
                        break;
        }

        if (k == -1 || k < f->index)
                /*
                 * All the unique pixel formats matching the arguments
                 * have been enumerated (k >= 0 and f->index > 0), or
                 * no pixel formats match the non-zero f->mbus_code (k == -1).
                 */
                return -EINVAL;

        f->pixelformat = video->formats[i].pixelformat;

        return 0;
}

static int video_enum_framesizes(struct file *file, void *fh,
                                 struct v4l2_frmsizeenum *fsize)
{
        struct camss_video *video = video_drvdata(file);
        int i;

        if (fsize->index)
                return -EINVAL;

        /* Only accept pixel format present in the formats[] table */
        for (i = 0; i < video->nformats; i++) {
                if (video->formats[i].pixelformat == fsize->pixel_format)
                        break;
        }

        if (i == video->nformats)
                return -EINVAL;

        fsize->type = V4L2_FRMSIZE_TYPE_CONTINUOUS;
        fsize->stepwise.min_width = CAMSS_FRAME_MIN_WIDTH;
        fsize->stepwise.max_width = CAMSS_FRAME_MAX_WIDTH;
        fsize->stepwise.min_height = CAMSS_FRAME_MIN_HEIGHT;
        fsize->stepwise.max_height = (video->line_based) ?
                CAMSS_FRAME_MAX_HEIGHT_PIX : CAMSS_FRAME_MAX_HEIGHT_RDI;
        fsize->stepwise.step_width = 1;
        fsize->stepwise.step_height = 1;

        return 0;
}

static int video_g_fmt(struct file *file, void *fh, struct v4l2_format *f)
{
        struct camss_video *video = video_drvdata(file);

        *f = video->active_fmt;

        return 0;
}

static int __video_try_fmt(struct camss_video *video, struct v4l2_format *f)
{
        unsigned int alignment = video->bpl_alignment;
        struct v4l2_pix_format_mplane *pix_mp;
        const struct camss_format_info *fi;
        struct v4l2_plane_pix_format *p;
        u32 bytesperline[3] = { 0 };
        u32 sizeimage[3] = { 0 };
        u32 width, height;
        u32 bpl, lines;
        int i, j;

        pix_mp = &f->fmt.pix_mp;

        if (video->line_based)
                for (i = 0; i < pix_mp->num_planes && i < 3; i++) {
                        p = &pix_mp->plane_fmt[i];
                        bytesperline[i] = clamp_t(u32, p->bytesperline,
                                                  1, 65528);
                        sizeimage[i] = clamp_t(u32, p->sizeimage,
                                               bytesperline[i],
                                               bytesperline[i] * CAMSS_FRAME_MAX_HEIGHT_PIX);
                }

        for (j = 0; j < video->nformats; j++)
                if (pix_mp->pixelformat == video->formats[j].pixelformat)
                        break;

        if (j == video->nformats)
                j = 0; /* default format */

        fi = &video->formats[j];
        width = pix_mp->width;
        height = pix_mp->height;

        if (!alignment)
                alignment = camss_format_get_bpl_alignment(fi);

        memset(pix_mp, 0, sizeof(*pix_mp));

        pix_mp->pixelformat = fi->pixelformat;
        pix_mp->width = clamp_t(u32, width, 1, CAMSS_FRAME_MAX_WIDTH);
        pix_mp->height = clamp_t(u32, height, 1, CAMSS_FRAME_MAX_HEIGHT_RDI);
        pix_mp->num_planes = fi->planes;
        for (i = 0; i < pix_mp->num_planes; i++) {
                bpl = pix_mp->width / fi->hsub[i].numerator *
                        fi->hsub[i].denominator * fi->bpp[i] / 8;
                bpl = roundup(bpl, alignment);
                pix_mp->plane_fmt[i].bytesperline = bpl;
                pix_mp->plane_fmt[i].sizeimage = pix_mp->height /
                        fi->vsub[i].numerator * fi->vsub[i].denominator * bpl;
        }

        pix_mp->field = V4L2_FIELD_NONE;
        pix_mp->colorspace = V4L2_COLORSPACE_SRGB;
        pix_mp->flags = 0;
        pix_mp->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(pix_mp->colorspace);
        pix_mp->quantization = V4L2_MAP_QUANTIZATION_DEFAULT(true,
                                        pix_mp->colorspace, pix_mp->ycbcr_enc);
        pix_mp->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(pix_mp->colorspace);

        if (video->line_based)
                for (i = 0; i < pix_mp->num_planes; i++) {
                        p = &pix_mp->plane_fmt[i];
                        p->bytesperline = clamp_t(u32, p->bytesperline,
                                                  1, 65528);
                        p->sizeimage = clamp_t(u32, p->sizeimage,
                                               p->bytesperline,
                                               p->bytesperline * CAMSS_FRAME_MAX_HEIGHT_PIX);
                        lines = p->sizeimage / p->bytesperline;

                        if (p->bytesperline < bytesperline[i])
                                p->bytesperline = roundup(bytesperline[i], alignment);

                        if (p->sizeimage < p->bytesperline * lines)
                                p->sizeimage = p->bytesperline * lines;

                        if (p->sizeimage < sizeimage[i])
                                p->sizeimage = sizeimage[i];
                }

        return 0;
}

static int video_try_fmt(struct file *file, void *fh, struct v4l2_format *f)
{
        struct camss_video *video = video_drvdata(file);

        return __video_try_fmt(video, f);
}

static int video_s_fmt(struct file *file, void *fh, struct v4l2_format *f)
{
        struct camss_video *video = video_drvdata(file);
        int ret;

        if (vb2_is_busy(&video->vb2_q))
                return -EBUSY;

        ret = __video_try_fmt(video, f);
        if (ret < 0)
                return ret;

        video->active_fmt = *f;

        return 0;
}

static int video_enum_input(struct file *file, void *fh,
                            struct v4l2_input *input)
{
        if (input->index > 0)
                return -EINVAL;

        strscpy(input->name, "camera", sizeof(input->name));
        input->type = V4L2_INPUT_TYPE_CAMERA;

        return 0;
}

static int video_g_input(struct file *file, void *fh, unsigned int *input)
{
        *input = 0;

        return 0;
}

static int video_s_input(struct file *file, void *fh, unsigned int input)
{
        return input == 0 ? 0 : -EINVAL;
}

static const struct v4l2_ioctl_ops msm_vid_ioctl_ops = {
        .vidioc_querycap                = video_querycap,
        .vidioc_enum_fmt_vid_cap        = video_enum_fmt,
        .vidioc_enum_framesizes         = video_enum_framesizes,
        .vidioc_g_fmt_vid_cap_mplane    = video_g_fmt,
        .vidioc_s_fmt_vid_cap_mplane    = video_s_fmt,
        .vidioc_try_fmt_vid_cap_mplane  = video_try_fmt,
        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
        .vidioc_querybuf                = vb2_ioctl_querybuf,
        .vidioc_qbuf                    = vb2_ioctl_qbuf,
        .vidioc_expbuf                  = vb2_ioctl_expbuf,
        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
        .vidioc_create_bufs             = vb2_ioctl_create_bufs,
        .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,
        .vidioc_enum_input              = video_enum_input,
        .vidioc_g_input                 = video_g_input,
        .vidioc_s_input                 = video_s_input,
};

/* -----------------------------------------------------------------------------
 * V4L2 file operations
 */

static const struct v4l2_file_operations msm_vid_fops = {
        .owner          = THIS_MODULE,
        .unlocked_ioctl = video_ioctl2,
        .open           = v4l2_fh_open,
        .release        = vb2_fop_release,
        .poll           = vb2_fop_poll,
        .mmap           = vb2_fop_mmap,
        .read           = vb2_fop_read,
};

/* -----------------------------------------------------------------------------
 * CAMSS video core
 */

static void msm_video_release(struct video_device *vdev)
{
        struct camss_video *video = video_get_drvdata(vdev);

        media_entity_cleanup(&vdev->entity);

        mutex_destroy(&video->q_lock);
        mutex_destroy(&video->lock);

        if (atomic_dec_and_test(&video->camss->ref_count))
                camss_delete(video->camss);
}

/*
 * msm_video_init_format - Helper function to initialize format
 * @video: struct camss_video
 *
 * Initialize pad format with default value.
 *
 * Return 0 on success or a negative error code otherwise
 */
static int msm_video_init_format(struct camss_video *video)
{
        int ret;
        struct v4l2_format format = {
                .type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE,
                .fmt.pix_mp = {
                        .width = 1920,
                        .height = 1080,
                        .pixelformat = video->formats[0].pixelformat,
                },
        };

        ret = __video_try_fmt(video, &format);
        if (ret < 0)
                return ret;

        video->active_fmt = format;

        return 0;
}

/*
 * msm_video_register - Register a video device node
 * @video: struct camss_video
 * @v4l2_dev: V4L2 device
 * @name: name to be used for the video device node
 *
 * Initialize and register a video device node to a V4L2 device. Also
 * initialize the vb2 queue.
 *
 * Return 0 on success or a negative error code otherwise
 */

int msm_video_register(struct camss_video *video, struct v4l2_device *v4l2_dev,
                       const char *name)
{
        struct media_pad *pad = &video->pad;
        struct video_device *vdev;
        struct vb2_queue *q;
        int ret;

        vdev = &video->vdev;

        mutex_init(&video->q_lock);

        q = &video->vb2_q;
        q->drv_priv = video;
        q->mem_ops = &vb2_dma_sg_memops;
        q->ops = &msm_video_vb2_q_ops;
        q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
        q->io_modes = VB2_DMABUF | VB2_MMAP | VB2_READ;
        q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        q->buf_struct_size = sizeof(struct camss_buffer);
        q->dev = video->camss->dev;
        q->lock = &video->q_lock;
        ret = vb2_queue_init(q);
        if (ret < 0) {
                dev_err(v4l2_dev->dev, "Failed to init vb2 queue: %d\n", ret);
                goto error_vb2_init;
        }

        pad->flags = MEDIA_PAD_FL_SINK;
        ret = media_entity_pads_init(&vdev->entity, 1, pad);
        if (ret < 0) {
                dev_err(v4l2_dev->dev, "Failed to init video entity: %d\n",
                        ret);
                goto error_vb2_init;
        }

        mutex_init(&video->lock);

        ret = msm_video_init_format(video);
        if (ret < 0) {
                dev_err(v4l2_dev->dev, "Failed to init format: %d\n", ret);
                goto error_video_register;
        }

        vdev->fops = &msm_vid_fops;
        vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_STREAMING
                          | V4L2_CAP_READWRITE | V4L2_CAP_IO_MC;
        vdev->ioctl_ops = &msm_vid_ioctl_ops;
        vdev->release = msm_video_release;
        vdev->v4l2_dev = v4l2_dev;
        vdev->vfl_dir = VFL_DIR_RX;
        vdev->queue = &video->vb2_q;
        vdev->lock = &video->lock;
        strscpy(vdev->name, name, sizeof(vdev->name));

        ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
        if (ret < 0) {
                dev_err(v4l2_dev->dev, "Failed to register video device: %d\n",
                        ret);
                goto error_video_register;
        }

        video_set_drvdata(vdev, video);
        atomic_inc(&video->camss->ref_count);

        return 0;

error_video_register:
        media_entity_cleanup(&vdev->entity);
        mutex_destroy(&video->lock);
error_vb2_init:
        mutex_destroy(&video->q_lock);

        return ret;
}

void msm_video_unregister(struct camss_video *video)
{
        atomic_inc(&video->camss->ref_count);
        vb2_video_unregister_device(&video->vdev);
        atomic_dec(&video->camss->ref_count);
}