root/drivers/staging/media/imx/imx-media-capture.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Video Capture Subdev for Freescale i.MX5/6 SOC
 *
 * Copyright (c) 2012-2016 Mentor Graphics Inc.
 */
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
#include <media/v4l2-fwnode.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mc.h>
#include <media/v4l2-subdev.h>
#include <media/videobuf2-dma-contig.h>
#include <video/imx-ipu-v3.h>
#include <media/imx.h>
#include "imx-media.h"

#define IMX_CAPTURE_NAME "imx-capture"

struct capture_priv {
        struct imx_media_dev *md;               /* Media device */
        struct device *dev;                     /* Physical device */

        struct imx_media_video_dev vdev;        /* Video device */
        struct media_pad vdev_pad;              /* Video device pad */

        struct v4l2_subdev *src_sd;             /* Source subdev */
        int src_sd_pad;                         /* Source subdev pad */

        struct mutex mutex;                     /* Protect vdev operations */

        struct vb2_queue q;                     /* The videobuf2 queue */
        struct list_head ready_q;               /* List of queued buffers */
        spinlock_t q_lock;                      /* Protect ready_q */

        struct v4l2_ctrl_handler ctrl_hdlr;     /* Controls inherited from subdevs */

        bool legacy_api;                        /* Use the legacy (pre-MC) API */
};

#define to_capture_priv(v) container_of(v, struct capture_priv, vdev)

/* In bytes, per queue */
#define VID_MEM_LIMIT   SZ_64M

/* -----------------------------------------------------------------------------
 * MC-Centric Video IOCTLs
 */

static const struct imx_media_pixfmt *capture_find_format(u32 code, u32 fourcc)
{
        const struct imx_media_pixfmt *cc;

        cc = imx_media_find_ipu_format(code, PIXFMT_SEL_YUV_RGB);
        if (cc) {
                enum imx_pixfmt_sel fmt_sel = cc->cs == IPUV3_COLORSPACE_YUV
                                            ? PIXFMT_SEL_YUV : PIXFMT_SEL_RGB;

                cc = imx_media_find_pixel_format(fourcc, fmt_sel);
                if (!cc) {
                        imx_media_enum_pixel_formats(&fourcc, 0, fmt_sel, 0);
                        cc = imx_media_find_pixel_format(fourcc, fmt_sel);
                }

                return cc;
        }

        return imx_media_find_mbus_format(code, PIXFMT_SEL_ANY);
}

static int capture_querycap(struct file *file, void *fh,
                            struct v4l2_capability *cap)
{
        struct capture_priv *priv = video_drvdata(file);

        strscpy(cap->driver, IMX_CAPTURE_NAME, sizeof(cap->driver));
        strscpy(cap->card, IMX_CAPTURE_NAME, sizeof(cap->card));
        snprintf(cap->bus_info, sizeof(cap->bus_info),
                 "platform:%s", dev_name(priv->dev));

        return 0;
}

static int capture_enum_fmt_vid_cap(struct file *file, void *fh,
                                    struct v4l2_fmtdesc *f)
{
        return imx_media_enum_pixel_formats(&f->pixelformat, f->index,
                                            PIXFMT_SEL_ANY, f->mbus_code);
}

static int capture_enum_framesizes(struct file *file, void *fh,
                                   struct v4l2_frmsizeenum *fsize)
{
        const struct imx_media_pixfmt *cc;

        if (fsize->index > 0)
                return -EINVAL;

        cc = imx_media_find_pixel_format(fsize->pixel_format, PIXFMT_SEL_ANY);
        if (!cc)
                return -EINVAL;

        /*
         * TODO: The constraints are hardware-specific and may depend on the
         * pixel format. This should come from the driver using
         * imx_media_capture.
         */
        fsize->type = V4L2_FRMSIZE_TYPE_CONTINUOUS;
        fsize->stepwise.min_width = 1;
        fsize->stepwise.max_width = 65535;
        fsize->stepwise.min_height = 1;
        fsize->stepwise.max_height = 65535;
        fsize->stepwise.step_width = 1;
        fsize->stepwise.step_height = 1;

        return 0;
}

static int capture_g_fmt_vid_cap(struct file *file, void *fh,
                                 struct v4l2_format *f)
{
        struct capture_priv *priv = video_drvdata(file);

        f->fmt.pix = priv->vdev.fmt;

        return 0;
}

static const struct imx_media_pixfmt *
__capture_try_fmt(struct v4l2_pix_format *pixfmt, struct v4l2_rect *compose)
{
        struct v4l2_mbus_framefmt fmt_src;
        const struct imx_media_pixfmt *cc;

        /*
         * Find the pixel format, default to the first supported format if not
         * found.
         */
        cc = imx_media_find_pixel_format(pixfmt->pixelformat, PIXFMT_SEL_ANY);
        if (!cc) {
                imx_media_enum_pixel_formats(&pixfmt->pixelformat, 0,
                                             PIXFMT_SEL_ANY, 0);
                cc = imx_media_find_pixel_format(pixfmt->pixelformat,
                                                 PIXFMT_SEL_ANY);
        }

        /* Allow IDMAC interweave but enforce field order from source. */
        if (V4L2_FIELD_IS_INTERLACED(pixfmt->field)) {
                switch (pixfmt->field) {
                case V4L2_FIELD_SEQ_TB:
                        pixfmt->field = V4L2_FIELD_INTERLACED_TB;
                        break;
                case V4L2_FIELD_SEQ_BT:
                        pixfmt->field = V4L2_FIELD_INTERLACED_BT;
                        break;
                default:
                        break;
                }
        }

        v4l2_fill_mbus_format(&fmt_src, pixfmt, 0);
        imx_media_mbus_fmt_to_pix_fmt(pixfmt, &fmt_src, cc);

        if (compose) {
                compose->width = fmt_src.width;
                compose->height = fmt_src.height;
        }

        return cc;
}

static int capture_try_fmt_vid_cap(struct file *file, void *fh,
                                   struct v4l2_format *f)
{
        __capture_try_fmt(&f->fmt.pix, NULL);
        return 0;
}

static int capture_s_fmt_vid_cap(struct file *file, void *fh,
                                 struct v4l2_format *f)
{
        struct capture_priv *priv = video_drvdata(file);
        const struct imx_media_pixfmt *cc;

        if (vb2_is_busy(&priv->q)) {
                dev_err(priv->dev, "%s queue busy\n", __func__);
                return -EBUSY;
        }

        cc = __capture_try_fmt(&f->fmt.pix, &priv->vdev.compose);

        priv->vdev.cc = cc;
        priv->vdev.fmt = f->fmt.pix;

        return 0;
}

static int capture_g_selection(struct file *file, void *fh,
                               struct v4l2_selection *s)
{
        struct capture_priv *priv = video_drvdata(file);

        switch (s->target) {
        case V4L2_SEL_TGT_COMPOSE:
        case V4L2_SEL_TGT_COMPOSE_DEFAULT:
        case V4L2_SEL_TGT_COMPOSE_BOUNDS:
                /* The compose rectangle is fixed to the source format. */
                s->r = priv->vdev.compose;
                break;
        case V4L2_SEL_TGT_COMPOSE_PADDED:
                /*
                 * The hardware writes with a configurable but fixed DMA burst
                 * size. If the source format width is not burst size aligned,
                 * the written frame contains padding to the right.
                 */
                s->r.left = 0;
                s->r.top = 0;
                s->r.width = priv->vdev.fmt.width;
                s->r.height = priv->vdev.fmt.height;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int capture_subscribe_event(struct v4l2_fh *fh,
                                   const struct v4l2_event_subscription *sub)
{
        switch (sub->type) {
        case V4L2_EVENT_IMX_FRAME_INTERVAL_ERROR:
                return v4l2_event_subscribe(fh, sub, 0, NULL);
        default:
                return -EINVAL;
        }
}

static const struct v4l2_ioctl_ops capture_ioctl_ops = {
        .vidioc_querycap                = capture_querycap,

        .vidioc_enum_fmt_vid_cap        = capture_enum_fmt_vid_cap,
        .vidioc_enum_framesizes         = capture_enum_framesizes,

        .vidioc_g_fmt_vid_cap           = capture_g_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap         = capture_try_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap           = capture_s_fmt_vid_cap,

        .vidioc_g_selection             = capture_g_selection,

        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
        .vidioc_create_bufs             = vb2_ioctl_create_bufs,
        .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
        .vidioc_querybuf                = vb2_ioctl_querybuf,
        .vidioc_qbuf                    = vb2_ioctl_qbuf,
        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
        .vidioc_expbuf                  = vb2_ioctl_expbuf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,

        .vidioc_subscribe_event         = capture_subscribe_event,
        .vidioc_unsubscribe_event       = v4l2_event_unsubscribe,
};

/* -----------------------------------------------------------------------------
 * Legacy Video IOCTLs
 */

static int capture_legacy_enum_framesizes(struct file *file, void *fh,
                                          struct v4l2_frmsizeenum *fsize)
{
        struct capture_priv *priv = video_drvdata(file);
        const struct imx_media_pixfmt *cc;
        struct v4l2_subdev_frame_size_enum fse = {
                .index = fsize->index,
                .pad = priv->src_sd_pad,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        int ret;

        cc = imx_media_find_pixel_format(fsize->pixel_format, PIXFMT_SEL_ANY);
        if (!cc)
                return -EINVAL;

        fse.code = cc->codes ? cc->codes[0] : 0;

        ret = v4l2_subdev_call(priv->src_sd, pad, enum_frame_size, NULL, &fse);
        if (ret)
                return ret;

        if (fse.min_width == fse.max_width &&
            fse.min_height == fse.max_height) {
                fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
                fsize->discrete.width = fse.min_width;
                fsize->discrete.height = fse.min_height;
        } else {
                fsize->type = V4L2_FRMSIZE_TYPE_CONTINUOUS;
                fsize->stepwise.min_width = fse.min_width;
                fsize->stepwise.max_width = fse.max_width;
                fsize->stepwise.min_height = fse.min_height;
                fsize->stepwise.max_height = fse.max_height;
                fsize->stepwise.step_width = 1;
                fsize->stepwise.step_height = 1;
        }

        return 0;
}

static int capture_legacy_enum_frameintervals(struct file *file, void *fh,
                                              struct v4l2_frmivalenum *fival)
{
        struct capture_priv *priv = video_drvdata(file);
        const struct imx_media_pixfmt *cc;
        struct v4l2_subdev_frame_interval_enum fie = {
                .index = fival->index,
                .pad = priv->src_sd_pad,
                .width = fival->width,
                .height = fival->height,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        int ret;

        cc = imx_media_find_pixel_format(fival->pixel_format, PIXFMT_SEL_ANY);
        if (!cc)
                return -EINVAL;

        fie.code = cc->codes ? cc->codes[0] : 0;

        ret = v4l2_subdev_call(priv->src_sd, pad, enum_frame_interval,
                               NULL, &fie);
        if (ret)
                return ret;

        fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
        fival->discrete = fie.interval;

        return 0;
}

static int capture_legacy_enum_fmt_vid_cap(struct file *file, void *fh,
                                           struct v4l2_fmtdesc *f)
{
        struct capture_priv *priv = video_drvdata(file);
        const struct imx_media_pixfmt *cc_src;
        struct v4l2_subdev_format fmt_src = {
                .pad = priv->src_sd_pad,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        u32 fourcc;
        int ret;

        ret = v4l2_subdev_call(priv->src_sd, pad, get_fmt, NULL, &fmt_src);
        if (ret) {
                dev_err(priv->dev, "failed to get src_sd format\n");
                return ret;
        }

        cc_src = imx_media_find_ipu_format(fmt_src.format.code,
                                           PIXFMT_SEL_YUV_RGB);
        if (cc_src) {
                enum imx_pixfmt_sel fmt_sel =
                        (cc_src->cs == IPUV3_COLORSPACE_YUV) ?
                        PIXFMT_SEL_YUV : PIXFMT_SEL_RGB;

                ret = imx_media_enum_pixel_formats(&fourcc, f->index, fmt_sel,
                                                   0);
                if (ret)
                        return ret;
        } else {
                cc_src = imx_media_find_mbus_format(fmt_src.format.code,
                                                    PIXFMT_SEL_ANY);
                if (WARN_ON(!cc_src))
                        return -EINVAL;

                if (f->index != 0)
                        return -EINVAL;
                fourcc = cc_src->fourcc;
        }

        f->pixelformat = fourcc;

        return 0;
}

static const struct imx_media_pixfmt *
__capture_legacy_try_fmt(struct capture_priv *priv,
                         struct v4l2_subdev_format *fmt_src,
                         struct v4l2_pix_format *pixfmt)
{
        const struct imx_media_pixfmt *cc;

        cc = capture_find_format(fmt_src->format.code, pixfmt->pixelformat);
        if (WARN_ON(!cc))
                return NULL;

        /* allow IDMAC interweave but enforce field order from source */
        if (V4L2_FIELD_IS_INTERLACED(pixfmt->field)) {
                switch (fmt_src->format.field) {
                case V4L2_FIELD_SEQ_TB:
                        fmt_src->format.field = V4L2_FIELD_INTERLACED_TB;
                        break;
                case V4L2_FIELD_SEQ_BT:
                        fmt_src->format.field = V4L2_FIELD_INTERLACED_BT;
                        break;
                default:
                        break;
                }
        }

        imx_media_mbus_fmt_to_pix_fmt(pixfmt, &fmt_src->format, cc);

        return cc;
}

static int capture_legacy_try_fmt_vid_cap(struct file *file, void *fh,
                                          struct v4l2_format *f)
{
        struct capture_priv *priv = video_drvdata(file);
        struct v4l2_subdev_format fmt_src = {
                .pad = priv->src_sd_pad,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        int ret;

        ret = v4l2_subdev_call(priv->src_sd, pad, get_fmt, NULL, &fmt_src);
        if (ret)
                return ret;

        if (!__capture_legacy_try_fmt(priv, &fmt_src, &f->fmt.pix))
                return -EINVAL;

        return 0;
}

static int capture_legacy_s_fmt_vid_cap(struct file *file, void *fh,
                                        struct v4l2_format *f)
{
        struct capture_priv *priv = video_drvdata(file);
        struct v4l2_subdev_format fmt_src = {
                .pad = priv->src_sd_pad,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        const struct imx_media_pixfmt *cc;
        int ret;

        if (vb2_is_busy(&priv->q)) {
                dev_err(priv->dev, "%s queue busy\n", __func__);
                return -EBUSY;
        }

        ret = v4l2_subdev_call(priv->src_sd, pad, get_fmt, NULL, &fmt_src);
        if (ret)
                return ret;

        cc = __capture_legacy_try_fmt(priv, &fmt_src, &f->fmt.pix);
        if (!cc)
                return -EINVAL;

        priv->vdev.cc = cc;
        priv->vdev.fmt = f->fmt.pix;
        priv->vdev.compose.width = fmt_src.format.width;
        priv->vdev.compose.height = fmt_src.format.height;

        return 0;
}

static int capture_legacy_querystd(struct file *file, void *fh,
                                   v4l2_std_id *std)
{
        struct capture_priv *priv = video_drvdata(file);

        return v4l2_subdev_call(priv->src_sd, video, querystd, std);
}

static int capture_legacy_g_std(struct file *file, void *fh, v4l2_std_id *std)
{
        struct capture_priv *priv = video_drvdata(file);

        return v4l2_subdev_call(priv->src_sd, video, g_std, std);
}

static int capture_legacy_s_std(struct file *file, void *fh, v4l2_std_id std)
{
        struct capture_priv *priv = video_drvdata(file);

        if (vb2_is_busy(&priv->q))
                return -EBUSY;

        return v4l2_subdev_call(priv->src_sd, video, s_std, std);
}

static int capture_legacy_g_parm(struct file *file, void *fh,
                                 struct v4l2_streamparm *a)
{
        struct capture_priv *priv = video_drvdata(file);
        struct v4l2_subdev_frame_interval fi = {
                .pad = priv->src_sd_pad,
        };
        int ret;

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

        ret = v4l2_subdev_call_state_active(priv->src_sd, pad,
                                            get_frame_interval, &fi);
        if (ret < 0)
                return ret;

        a->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
        a->parm.capture.timeperframe = fi.interval;

        return 0;
}

static int capture_legacy_s_parm(struct file *file, void *fh,
                                 struct v4l2_streamparm *a)
{
        struct capture_priv *priv = video_drvdata(file);
        struct v4l2_subdev_frame_interval fi = {
                .pad = priv->src_sd_pad,
        };
        int ret;

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

        fi.interval = a->parm.capture.timeperframe;
        ret = v4l2_subdev_call_state_active(priv->src_sd, pad,
                                            set_frame_interval, &fi);
        if (ret < 0)
                return ret;

        a->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
        a->parm.capture.timeperframe = fi.interval;

        return 0;
}

static int capture_legacy_subscribe_event(struct v4l2_fh *fh,
                                          const struct v4l2_event_subscription *sub)
{
        switch (sub->type) {
        case V4L2_EVENT_IMX_FRAME_INTERVAL_ERROR:
                return v4l2_event_subscribe(fh, sub, 0, NULL);
        case V4L2_EVENT_SOURCE_CHANGE:
                return v4l2_src_change_event_subscribe(fh, sub);
        case V4L2_EVENT_CTRL:
                return v4l2_ctrl_subscribe_event(fh, sub);
        default:
                return -EINVAL;
        }
}

static const struct v4l2_ioctl_ops capture_legacy_ioctl_ops = {
        .vidioc_querycap                = capture_querycap,

        .vidioc_enum_framesizes         = capture_legacy_enum_framesizes,
        .vidioc_enum_frameintervals     = capture_legacy_enum_frameintervals,

        .vidioc_enum_fmt_vid_cap        = capture_legacy_enum_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap           = capture_g_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap         = capture_legacy_try_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap           = capture_legacy_s_fmt_vid_cap,

        .vidioc_querystd                = capture_legacy_querystd,
        .vidioc_g_std                   = capture_legacy_g_std,
        .vidioc_s_std                   = capture_legacy_s_std,

        .vidioc_g_selection             = capture_g_selection,

        .vidioc_g_parm                  = capture_legacy_g_parm,
        .vidioc_s_parm                  = capture_legacy_s_parm,

        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
        .vidioc_create_bufs             = vb2_ioctl_create_bufs,
        .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
        .vidioc_querybuf                = vb2_ioctl_querybuf,
        .vidioc_qbuf                    = vb2_ioctl_qbuf,
        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
        .vidioc_expbuf                  = vb2_ioctl_expbuf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,

        .vidioc_subscribe_event         = capture_legacy_subscribe_event,
        .vidioc_unsubscribe_event       = v4l2_event_unsubscribe,
};

/* -----------------------------------------------------------------------------
 * Queue Operations
 */

static int capture_queue_setup(struct vb2_queue *vq,
                               unsigned int *nbuffers,
                               unsigned int *nplanes,
                               unsigned int sizes[],
                               struct device *alloc_devs[])
{
        struct capture_priv *priv = vb2_get_drv_priv(vq);
        struct v4l2_pix_format *pix = &priv->vdev.fmt;
        unsigned int q_num_bufs = vb2_get_num_buffers(vq);
        unsigned int count = *nbuffers;

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

        if (*nplanes) {
                if (*nplanes != 1 || sizes[0] < pix->sizeimage)
                        return -EINVAL;
                count += q_num_bufs;
        }

        count = min_t(__u32, VID_MEM_LIMIT / pix->sizeimage, count);

        if (*nplanes)
                *nbuffers = (count < q_num_bufs) ? 0 :
                        count - q_num_bufs;
        else
                *nbuffers = count;

        *nplanes = 1;
        sizes[0] = pix->sizeimage;

        return 0;
}

static int capture_buf_init(struct vb2_buffer *vb)
{
        struct imx_media_buffer *buf = to_imx_media_vb(vb);

        INIT_LIST_HEAD(&buf->list);

        return 0;
}

static int capture_buf_prepare(struct vb2_buffer *vb)
{
        struct vb2_queue *vq = vb->vb2_queue;
        struct capture_priv *priv = vb2_get_drv_priv(vq);
        struct v4l2_pix_format *pix = &priv->vdev.fmt;

        if (vb2_plane_size(vb, 0) < pix->sizeimage) {
                dev_err(priv->dev,
                        "data will not fit into plane (%lu < %lu)\n",
                        vb2_plane_size(vb, 0), (long)pix->sizeimage);
                return -EINVAL;
        }

        vb2_set_plane_payload(vb, 0, pix->sizeimage);

        return 0;
}

static void capture_buf_queue(struct vb2_buffer *vb)
{
        struct capture_priv *priv = vb2_get_drv_priv(vb->vb2_queue);
        struct imx_media_buffer *buf = to_imx_media_vb(vb);
        unsigned long flags;

        spin_lock_irqsave(&priv->q_lock, flags);

        list_add_tail(&buf->list, &priv->ready_q);

        spin_unlock_irqrestore(&priv->q_lock, flags);
}

static int capture_validate_fmt(struct capture_priv *priv)
{
        struct v4l2_subdev_format fmt_src = {
                .pad = priv->src_sd_pad,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        const struct imx_media_pixfmt *cc;
        int ret;

        /* Retrieve the media bus format on the source subdev. */
        ret = v4l2_subdev_call(priv->src_sd, pad, get_fmt, NULL, &fmt_src);
        if (ret)
                return ret;

        /*
         * Verify that the media bus size matches the size set on the video
         * node. It is sufficient to check the compose rectangle size without
         * checking the rounded size from vdev.fmt, as the rounded size is
         * derived directly from the compose rectangle size, and will thus
         * always match if the compose rectangle matches.
         */
        if (priv->vdev.compose.width != fmt_src.format.width ||
            priv->vdev.compose.height != fmt_src.format.height)
                return -EPIPE;

        /*
         * Verify that the media bus code is compatible with the pixel format
         * set on the video node.
         */
        cc = capture_find_format(fmt_src.format.code, 0);
        if (!cc || priv->vdev.cc->cs != cc->cs)
                return -EPIPE;

        return 0;
}

static int capture_start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct capture_priv *priv = vb2_get_drv_priv(vq);
        struct imx_media_buffer *buf, *tmp;
        unsigned long flags;
        int ret;

        ret = capture_validate_fmt(priv);
        if (ret) {
                dev_err(priv->dev, "capture format not valid\n");
                goto return_bufs;
        }

        ret = imx_media_pipeline_set_stream(priv->md, &priv->src_sd->entity,
                                            true);
        if (ret) {
                dev_err(priv->dev, "pipeline start failed with %d\n", ret);
                goto return_bufs;
        }

        return 0;

return_bufs:
        spin_lock_irqsave(&priv->q_lock, flags);
        list_for_each_entry_safe(buf, tmp, &priv->ready_q, list) {
                list_del(&buf->list);
                vb2_buffer_done(&buf->vbuf.vb2_buf, VB2_BUF_STATE_QUEUED);
        }
        spin_unlock_irqrestore(&priv->q_lock, flags);
        return ret;
}

static void capture_stop_streaming(struct vb2_queue *vq)
{
        struct capture_priv *priv = vb2_get_drv_priv(vq);
        struct imx_media_buffer *frame;
        struct imx_media_buffer *tmp;
        unsigned long flags;
        int ret;

        ret = imx_media_pipeline_set_stream(priv->md, &priv->src_sd->entity,
                                            false);
        if (ret)
                dev_warn(priv->dev, "pipeline stop failed with %d\n", ret);

        /* release all active buffers */
        spin_lock_irqsave(&priv->q_lock, flags);
        list_for_each_entry_safe(frame, tmp, &priv->ready_q, list) {
                list_del(&frame->list);
                vb2_buffer_done(&frame->vbuf.vb2_buf, VB2_BUF_STATE_ERROR);
        }
        spin_unlock_irqrestore(&priv->q_lock, flags);
}

static const struct vb2_ops capture_qops = {
        .queue_setup     = capture_queue_setup,
        .buf_init        = capture_buf_init,
        .buf_prepare     = capture_buf_prepare,
        .buf_queue       = capture_buf_queue,
        .start_streaming = capture_start_streaming,
        .stop_streaming  = capture_stop_streaming,
};

/* -----------------------------------------------------------------------------
 * File Operations
 */

static int capture_open(struct file *file)
{
        struct capture_priv *priv = video_drvdata(file);
        struct video_device *vfd = priv->vdev.vfd;
        int ret;

        if (mutex_lock_interruptible(&priv->mutex))
                return -ERESTARTSYS;

        ret = v4l2_fh_open(file);
        if (ret) {
                dev_err(priv->dev, "v4l2_fh_open failed\n");
                goto out;
        }

        ret = v4l2_pipeline_pm_get(&vfd->entity);
        if (ret)
                v4l2_fh_release(file);

out:
        mutex_unlock(&priv->mutex);
        return ret;
}

static int capture_release(struct file *file)
{
        struct capture_priv *priv = video_drvdata(file);
        struct video_device *vfd = priv->vdev.vfd;
        struct vb2_queue *vq = &priv->q;

        mutex_lock(&priv->mutex);

        if (file->private_data == vq->owner) {
                vb2_queue_release(vq);
                vq->owner = NULL;
        }

        v4l2_pipeline_pm_put(&vfd->entity);

        v4l2_fh_release(file);
        mutex_unlock(&priv->mutex);
        return 0;
}

static const struct v4l2_file_operations capture_fops = {
        .owner          = THIS_MODULE,
        .open           = capture_open,
        .release        = capture_release,
        .poll           = vb2_fop_poll,
        .unlocked_ioctl = video_ioctl2,
        .mmap           = vb2_fop_mmap,
};

/* -----------------------------------------------------------------------------
 * Public API
 */

struct imx_media_buffer *
imx_media_capture_device_next_buf(struct imx_media_video_dev *vdev)
{
        struct capture_priv *priv = to_capture_priv(vdev);
        struct imx_media_buffer *buf = NULL;
        unsigned long flags;

        spin_lock_irqsave(&priv->q_lock, flags);

        /* get next queued buffer */
        if (!list_empty(&priv->ready_q)) {
                buf = list_entry(priv->ready_q.next, struct imx_media_buffer,
                                 list);
                list_del(&buf->list);
        }

        spin_unlock_irqrestore(&priv->q_lock, flags);

        return buf;
}
EXPORT_SYMBOL_GPL(imx_media_capture_device_next_buf);

void imx_media_capture_device_error(struct imx_media_video_dev *vdev)
{
        struct capture_priv *priv = to_capture_priv(vdev);
        struct vb2_queue *vq = &priv->q;
        unsigned long flags;

        if (!vb2_is_streaming(vq))
                return;

        spin_lock_irqsave(&priv->q_lock, flags);
        vb2_queue_error(vq);
        spin_unlock_irqrestore(&priv->q_lock, flags);
}
EXPORT_SYMBOL_GPL(imx_media_capture_device_error);

static int capture_init_format(struct capture_priv *priv)
{
        struct v4l2_subdev_format fmt_src = {
                .pad = priv->src_sd_pad,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        struct imx_media_video_dev *vdev = &priv->vdev;
        int ret;

        if (priv->legacy_api) {
                ret = v4l2_subdev_call(priv->src_sd, pad, get_fmt, NULL,
                                       &fmt_src);
                if (ret) {
                        dev_err(priv->dev, "failed to get source format\n");
                        return ret;
                }
        } else {
                fmt_src.format.code = MEDIA_BUS_FMT_UYVY8_2X8;
                fmt_src.format.width = IMX_MEDIA_DEF_PIX_WIDTH;
                fmt_src.format.height = IMX_MEDIA_DEF_PIX_HEIGHT;
        }

        imx_media_mbus_fmt_to_pix_fmt(&vdev->fmt, &fmt_src.format, NULL);
        vdev->compose.width = fmt_src.format.width;
        vdev->compose.height = fmt_src.format.height;

        vdev->cc = imx_media_find_pixel_format(vdev->fmt.pixelformat,
                                               PIXFMT_SEL_ANY);

        return 0;
}

int imx_media_capture_device_register(struct imx_media_video_dev *vdev,
                                      u32 link_flags)
{
        struct capture_priv *priv = to_capture_priv(vdev);
        struct v4l2_subdev *sd = priv->src_sd;
        struct v4l2_device *v4l2_dev = sd->v4l2_dev;
        struct video_device *vfd = vdev->vfd;
        int ret;

        /* get media device */
        priv->md = container_of(v4l2_dev->mdev, struct imx_media_dev, md);

        vfd->v4l2_dev = v4l2_dev;

        /* Initialize the default format and compose rectangle. */
        ret = capture_init_format(priv);
        if (ret < 0)
                return ret;

        /* Register the video device. */
        ret = video_register_device(vfd, VFL_TYPE_VIDEO, -1);
        if (ret) {
                dev_err(priv->dev, "Failed to register video device\n");
                return ret;
        }

        dev_info(priv->dev, "Registered %s as /dev/%s\n", vfd->name,
                 video_device_node_name(vfd));

        /* Create the link from the src_sd devnode pad to device node. */
        if (link_flags & MEDIA_LNK_FL_IMMUTABLE)
                link_flags |= MEDIA_LNK_FL_ENABLED;
        ret = media_create_pad_link(&sd->entity, priv->src_sd_pad,
                                    &vfd->entity, 0, link_flags);
        if (ret) {
                dev_err(priv->dev, "failed to create link to device node\n");
                video_unregister_device(vfd);
                return ret;
        }

        /* Add vdev to the video devices list. */
        imx_media_add_video_device(priv->md, vdev);

        return 0;
}
EXPORT_SYMBOL_GPL(imx_media_capture_device_register);

void imx_media_capture_device_unregister(struct imx_media_video_dev *vdev)
{
        struct capture_priv *priv = to_capture_priv(vdev);
        struct video_device *vfd = priv->vdev.vfd;

        media_entity_cleanup(&vfd->entity);
        video_unregister_device(vfd);
}
EXPORT_SYMBOL_GPL(imx_media_capture_device_unregister);

struct imx_media_video_dev *
imx_media_capture_device_init(struct device *dev, struct v4l2_subdev *src_sd,
                              int pad, bool legacy_api)
{
        struct capture_priv *priv;
        struct video_device *vfd;
        struct vb2_queue *vq;
        int ret;

        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return ERR_PTR(-ENOMEM);

        priv->src_sd = src_sd;
        priv->src_sd_pad = pad;
        priv->dev = dev;
        priv->legacy_api = legacy_api;

        mutex_init(&priv->mutex);
        INIT_LIST_HEAD(&priv->ready_q);
        spin_lock_init(&priv->q_lock);

        /* Allocate and initialize the video device. */
        vfd = video_device_alloc();
        if (!vfd)
                return ERR_PTR(-ENOMEM);

        vfd->fops = &capture_fops;
        vfd->ioctl_ops = legacy_api ? &capture_legacy_ioctl_ops
                       : &capture_ioctl_ops;
        vfd->minor = -1;
        vfd->release = video_device_release;
        vfd->vfl_dir = VFL_DIR_RX;
        vfd->tvnorms = V4L2_STD_NTSC | V4L2_STD_PAL | V4L2_STD_SECAM;
        vfd->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING
                         | (!legacy_api ? V4L2_CAP_IO_MC : 0);
        vfd->lock = &priv->mutex;
        vfd->queue = &priv->q;

        snprintf(vfd->name, sizeof(vfd->name), "%s capture", src_sd->name);

        video_set_drvdata(vfd, priv);
        priv->vdev.vfd = vfd;
        INIT_LIST_HEAD(&priv->vdev.list);

        /* Initialize the video device pad. */
        priv->vdev_pad.flags = MEDIA_PAD_FL_SINK;
        ret = media_entity_pads_init(&vfd->entity, 1, &priv->vdev_pad);
        if (ret) {
                video_device_release(vfd);
                return ERR_PTR(ret);
        }

        /* Initialize the vb2 queue. */
        vq = &priv->q;
        vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        vq->io_modes = VB2_MMAP | VB2_DMABUF;
        vq->drv_priv = priv;
        vq->buf_struct_size = sizeof(struct imx_media_buffer);
        vq->ops = &capture_qops;
        vq->mem_ops = &vb2_dma_contig_memops;
        vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        vq->lock = &priv->mutex;
        vq->min_queued_buffers = 2;
        vq->dev = priv->dev;

        ret = vb2_queue_init(vq);
        if (ret) {
                dev_err(priv->dev, "vb2_queue_init failed\n");
                video_device_release(vfd);
                return ERR_PTR(ret);
        }

        if (legacy_api) {
                /* Initialize the control handler. */
                v4l2_ctrl_handler_init(&priv->ctrl_hdlr, 0);
                vfd->ctrl_handler = &priv->ctrl_hdlr;
        }

        return &priv->vdev;
}
EXPORT_SYMBOL_GPL(imx_media_capture_device_init);

void imx_media_capture_device_remove(struct imx_media_video_dev *vdev)
{
        struct capture_priv *priv = to_capture_priv(vdev);

        v4l2_ctrl_handler_free(&priv->ctrl_hdlr);
}
EXPORT_SYMBOL_GPL(imx_media_capture_device_remove);

MODULE_DESCRIPTION("i.MX5/6 v4l2 video capture interface driver");
MODULE_AUTHOR("Steve Longerbeam <steve_longerbeam@mentor.com>");
MODULE_LICENSE("GPL");