PM / sleep: Asynchronous threads for suspend_noirq

[linux/fpc-iii.git] / drivers / media / platform / exynos4-is / fimc-m2m.c

/*
 * Samsung S5P/EXYNOS4 SoC series FIMC (video postprocessor) driver
 *
 * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
 * Sylwester Nawrocki <s.nawrocki@samsung.com>
 *
 * 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/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/bug.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <media/v4l2-ioctl.h>
#include <media/videobuf2-core.h>
#include <media/videobuf2-dma-contig.h>

#include "common.h"
#include "fimc-core.h"
#include "fimc-reg.h"
#include "media-dev.h"

static unsigned int get_m2m_fmt_flags(unsigned int stream_type)
{
        if (stream_type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
                return FMT_FLAGS_M2M_IN;
        else
                return FMT_FLAGS_M2M_OUT;
}

void fimc_m2m_job_finish(struct fimc_ctx *ctx, int vb_state)
{
        struct vb2_buffer *src_vb, *dst_vb;

        if (!ctx || !ctx->fh.m2m_ctx)
                return;

        src_vb = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
        dst_vb = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);

        if (src_vb && dst_vb) {
                v4l2_m2m_buf_done(src_vb, vb_state);
                v4l2_m2m_buf_done(dst_vb, vb_state);
                v4l2_m2m_job_finish(ctx->fimc_dev->m2m.m2m_dev,
                                    ctx->fh.m2m_ctx);
        }
}

/* Complete the transaction which has been scheduled for execution. */
static int fimc_m2m_shutdown(struct fimc_ctx *ctx)
{
        struct fimc_dev *fimc = ctx->fimc_dev;
        int ret;

        if (!fimc_m2m_pending(fimc))
                return 0;

        fimc_ctx_state_set(FIMC_CTX_SHUT, ctx);

        ret = wait_event_timeout(fimc->irq_queue,
                           !fimc_ctx_state_is_set(FIMC_CTX_SHUT, ctx),
                           FIMC_SHUTDOWN_TIMEOUT);

        return ret == 0 ? -ETIMEDOUT : ret;
}

static int start_streaming(struct vb2_queue *q, unsigned int count)
{
        struct fimc_ctx *ctx = q->drv_priv;
        int ret;

        ret = pm_runtime_get_sync(&ctx->fimc_dev->pdev->dev);
        return ret > 0 ? 0 : ret;
}

static int stop_streaming(struct vb2_queue *q)
{
        struct fimc_ctx *ctx = q->drv_priv;
        int ret;

        ret = fimc_m2m_shutdown(ctx);
        if (ret == -ETIMEDOUT)
                fimc_m2m_job_finish(ctx, VB2_BUF_STATE_ERROR);

        pm_runtime_put(&ctx->fimc_dev->pdev->dev);
        return 0;
}

static void fimc_device_run(void *priv)
{
        struct vb2_buffer *src_vb, *dst_vb;
        struct fimc_ctx *ctx = priv;
        struct fimc_frame *sf, *df;
        struct fimc_dev *fimc;
        unsigned long flags;
        int ret;

        if (WARN(!ctx, "Null context\n"))
                return;

        fimc = ctx->fimc_dev;
        spin_lock_irqsave(&fimc->slock, flags);

        set_bit(ST_M2M_PEND, &fimc->state);
        sf = &ctx->s_frame;
        df = &ctx->d_frame;

        if (ctx->state & FIMC_PARAMS) {
                /* Prepare the DMA offsets for scaler */
                fimc_prepare_dma_offset(ctx, sf);
                fimc_prepare_dma_offset(ctx, df);
        }

        src_vb = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
        ret = fimc_prepare_addr(ctx, src_vb, sf, &sf->paddr);
        if (ret)
                goto dma_unlock;

        dst_vb = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
        ret = fimc_prepare_addr(ctx, dst_vb, df, &df->paddr);
        if (ret)
                goto dma_unlock;

        dst_vb->v4l2_buf.timestamp = src_vb->v4l2_buf.timestamp;

        /* Reconfigure hardware if the context has changed. */
        if (fimc->m2m.ctx != ctx) {
                ctx->state |= FIMC_PARAMS;
                fimc->m2m.ctx = ctx;
        }

        if (ctx->state & FIMC_PARAMS) {
                fimc_set_yuv_order(ctx);
                fimc_hw_set_input_path(ctx);
                fimc_hw_set_in_dma(ctx);
                ret = fimc_set_scaler_info(ctx);
                if (ret)
                        goto dma_unlock;
                fimc_hw_set_prescaler(ctx);
                fimc_hw_set_mainscaler(ctx);
                fimc_hw_set_target_format(ctx);
                fimc_hw_set_rotation(ctx);
                fimc_hw_set_effect(ctx);
                fimc_hw_set_out_dma(ctx);
                if (fimc->drv_data->alpha_color)
                        fimc_hw_set_rgb_alpha(ctx);
                fimc_hw_set_output_path(ctx);
        }
        fimc_hw_set_input_addr(fimc, &sf->paddr);
        fimc_hw_set_output_addr(fimc, &df->paddr, -1);

        fimc_activate_capture(ctx);
        ctx->state &= (FIMC_CTX_M2M | FIMC_CTX_CAP);
        fimc_hw_activate_input_dma(fimc, true);

dma_unlock:
        spin_unlock_irqrestore(&fimc->slock, flags);
}

static void fimc_job_abort(void *priv)
{
        fimc_m2m_shutdown(priv);
}

static int fimc_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
                            unsigned int *num_buffers, unsigned int *num_planes,
                            unsigned int sizes[], void *allocators[])
{
        struct fimc_ctx *ctx = vb2_get_drv_priv(vq);
        struct fimc_frame *f;
        int i;

        f = ctx_get_frame(ctx, vq->type);
        if (IS_ERR(f))
                return PTR_ERR(f);
        /*
         * Return number of non-contigous planes (plane buffers)
         * depending on the configured color format.
         */
        if (!f->fmt)
                return -EINVAL;

        *num_planes = f->fmt->memplanes;
        for (i = 0; i < f->fmt->memplanes; i++) {
                sizes[i] = (f->f_width * f->f_height * f->fmt->depth[i]) / 8;
                allocators[i] = ctx->fimc_dev->alloc_ctx;
        }
        return 0;
}

static int fimc_buf_prepare(struct vb2_buffer *vb)
{
        struct fimc_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
        struct fimc_frame *frame;
        int i;

        frame = ctx_get_frame(ctx, vb->vb2_queue->type);
        if (IS_ERR(frame))
                return PTR_ERR(frame);

        for (i = 0; i < frame->fmt->memplanes; i++)
                vb2_set_plane_payload(vb, i, frame->payload[i]);

        return 0;
}

static void fimc_buf_queue(struct vb2_buffer *vb)
{
        struct fimc_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
        v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vb);
}

static struct vb2_ops fimc_qops = {
        .queue_setup     = fimc_queue_setup,
        .buf_prepare     = fimc_buf_prepare,
        .buf_queue       = fimc_buf_queue,
        .wait_prepare    = vb2_ops_wait_prepare,
        .wait_finish     = vb2_ops_wait_finish,
        .stop_streaming  = stop_streaming,
        .start_streaming = start_streaming,
};

/*
 * V4L2 ioctl handlers
 */
static int fimc_m2m_querycap(struct file *file, void *fh,
                                     struct v4l2_capability *cap)
{
        struct fimc_dev *fimc = video_drvdata(file);
        unsigned int caps;

        /*
         * This is only a mem-to-mem video device. The capture and output
         * device capability flags are left only for backward compatibility
         * and are scheduled for removal.
         */
        caps = V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_M2M_MPLANE |
                V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_VIDEO_OUTPUT_MPLANE;

        __fimc_vidioc_querycap(&fimc->pdev->dev, cap, caps);
        return 0;
}

static int fimc_m2m_enum_fmt_mplane(struct file *file, void *priv,
                                    struct v4l2_fmtdesc *f)
{
        struct fimc_fmt *fmt;

        fmt = fimc_find_format(NULL, NULL, get_m2m_fmt_flags(f->type),
                               f->index);
        if (!fmt)
                return -EINVAL;

        strncpy(f->description, fmt->name, sizeof(f->description) - 1);
        f->pixelformat = fmt->fourcc;
        return 0;
}

static int fimc_m2m_g_fmt_mplane(struct file *file, void *fh,
                                 struct v4l2_format *f)
{
        struct fimc_ctx *ctx = fh_to_ctx(fh);
        struct fimc_frame *frame = ctx_get_frame(ctx, f->type);

        if (IS_ERR(frame))
                return PTR_ERR(frame);

        __fimc_get_format(frame, f);
        return 0;
}

static int fimc_try_fmt_mplane(struct fimc_ctx *ctx, struct v4l2_format *f)
{
        struct fimc_dev *fimc = ctx->fimc_dev;
        const struct fimc_variant *variant = fimc->variant;
        struct v4l2_pix_format_mplane *pix = &f->fmt.pix_mp;
        struct fimc_fmt *fmt;
        u32 max_w, mod_x, mod_y;

        if (!IS_M2M(f->type))
                return -EINVAL;

        fmt = fimc_find_format(&pix->pixelformat, NULL,
                               get_m2m_fmt_flags(f->type), 0);
        if (WARN(fmt == NULL, "Pixel format lookup failed"))
                return -EINVAL;

        if (pix->field == V4L2_FIELD_ANY)
                pix->field = V4L2_FIELD_NONE;
        else if (pix->field != V4L2_FIELD_NONE)
                return -EINVAL;

        if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
                max_w = variant->pix_limit->scaler_dis_w;
                mod_x = ffs(variant->min_inp_pixsize) - 1;
        } else {
                max_w = variant->pix_limit->out_rot_dis_w;
                mod_x = ffs(variant->min_out_pixsize) - 1;
        }

        if (tiled_fmt(fmt)) {
                mod_x = 6; /* 64 x 32 pixels tile */
                mod_y = 5;
        } else {
                if (variant->min_vsize_align == 1)
                        mod_y = fimc_fmt_is_rgb(fmt->color) ? 0 : 1;
                else
                        mod_y = ffs(variant->min_vsize_align) - 1;
        }

        v4l_bound_align_image(&pix->width, 16, max_w, mod_x,
                &pix->height, 8, variant->pix_limit->scaler_dis_w, mod_y, 0);

        fimc_adjust_mplane_format(fmt, pix->width, pix->height, &f->fmt.pix_mp);
        return 0;
}

static int fimc_m2m_try_fmt_mplane(struct file *file, void *fh,
                                   struct v4l2_format *f)
{
        struct fimc_ctx *ctx = fh_to_ctx(fh);
        return fimc_try_fmt_mplane(ctx, f);
}

static void __set_frame_format(struct fimc_frame *frame, struct fimc_fmt *fmt,
                               struct v4l2_pix_format_mplane *pixm)
{
        int i;

        for (i = 0; i < fmt->colplanes; i++) {
                frame->bytesperline[i] = pixm->plane_fmt[i].bytesperline;
                frame->payload[i] = pixm->plane_fmt[i].sizeimage;
        }

        frame->f_width = pixm->width;
        frame->f_height = pixm->height;
        frame->o_width = pixm->width;
        frame->o_height = pixm->height;
        frame->width = pixm->width;
        frame->height = pixm->height;
        frame->offs_h = 0;
        frame->offs_v = 0;
        frame->fmt = fmt;
}

static int fimc_m2m_s_fmt_mplane(struct file *file, void *fh,
                                 struct v4l2_format *f)
{
        struct fimc_ctx *ctx = fh_to_ctx(fh);
        struct fimc_dev *fimc = ctx->fimc_dev;
        struct fimc_fmt *fmt;
        struct vb2_queue *vq;
        struct fimc_frame *frame;
        int ret;

        ret = fimc_try_fmt_mplane(ctx, f);
        if (ret)
                return ret;

        vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);

        if (vb2_is_busy(vq)) {
                v4l2_err(&fimc->m2m.vfd, "queue (%d) busy\n", f->type);
                return -EBUSY;
        }

        if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
                frame = &ctx->s_frame;
        else
                frame = &ctx->d_frame;

        fmt = fimc_find_format(&f->fmt.pix_mp.pixelformat, NULL,
                               get_m2m_fmt_flags(f->type), 0);
        if (!fmt)
                return -EINVAL;

        __set_frame_format(frame, fmt, &f->fmt.pix_mp);

        /* Update RGB Alpha control state and value range */
        fimc_alpha_ctrl_update(ctx);

        return 0;
}

static int fimc_m2m_cropcap(struct file *file, void *fh,
                            struct v4l2_cropcap *cr)
{
        struct fimc_ctx *ctx = fh_to_ctx(fh);
        struct fimc_frame *frame;

        frame = ctx_get_frame(ctx, cr->type);
        if (IS_ERR(frame))
                return PTR_ERR(frame);

        cr->bounds.left = 0;
        cr->bounds.top = 0;
        cr->bounds.width = frame->o_width;
        cr->bounds.height = frame->o_height;
        cr->defrect = cr->bounds;

        return 0;
}

static int fimc_m2m_g_crop(struct file *file, void *fh, struct v4l2_crop *cr)
{
        struct fimc_ctx *ctx = fh_to_ctx(fh);
        struct fimc_frame *frame;

        frame = ctx_get_frame(ctx, cr->type);
        if (IS_ERR(frame))
                return PTR_ERR(frame);

        cr->c.left = frame->offs_h;
        cr->c.top = frame->offs_v;
        cr->c.width = frame->width;
        cr->c.height = frame->height;

        return 0;
}

static int fimc_m2m_try_crop(struct fimc_ctx *ctx, struct v4l2_crop *cr)
{
        struct fimc_dev *fimc = ctx->fimc_dev;
        struct fimc_frame *f;
        u32 min_size, halign, depth = 0;
        int i;

        if (cr->c.top < 0 || cr->c.left < 0) {
                v4l2_err(&fimc->m2m.vfd,
                        "doesn't support negative values for top & left\n");
                return -EINVAL;
        }
        if (cr->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
                f = &ctx->d_frame;
        else if (cr->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
                f = &ctx->s_frame;
        else
                return -EINVAL;

        min_size = (f == &ctx->s_frame) ?
                fimc->variant->min_inp_pixsize : fimc->variant->min_out_pixsize;

        /* Get pixel alignment constraints. */
        if (fimc->variant->min_vsize_align == 1)
                halign = fimc_fmt_is_rgb(f->fmt->color) ? 0 : 1;
        else
                halign = ffs(fimc->variant->min_vsize_align) - 1;

        for (i = 0; i < f->fmt->colplanes; i++)
                depth += f->fmt->depth[i];

        v4l_bound_align_image(&cr->c.width, min_size, f->o_width,
                              ffs(min_size) - 1,
                              &cr->c.height, min_size, f->o_height,
                              halign, 64/(ALIGN(depth, 8)));

        /* adjust left/top if cropping rectangle is out of bounds */
        if (cr->c.left + cr->c.width > f->o_width)
                cr->c.left = f->o_width - cr->c.width;
        if (cr->c.top + cr->c.height > f->o_height)
                cr->c.top = f->o_height - cr->c.height;

        cr->c.left = round_down(cr->c.left, min_size);
        cr->c.top  = round_down(cr->c.top, fimc->variant->hor_offs_align);

        dbg("l:%d, t:%d, w:%d, h:%d, f_w: %d, f_h: %d",
            cr->c.left, cr->c.top, cr->c.width, cr->c.height,
            f->f_width, f->f_height);

        return 0;
}

static int fimc_m2m_s_crop(struct file *file, void *fh, const struct v4l2_crop *crop)
{
        struct fimc_ctx *ctx = fh_to_ctx(fh);
        struct fimc_dev *fimc = ctx->fimc_dev;
        struct v4l2_crop cr = *crop;
        struct fimc_frame *f;
        int ret;

        ret = fimc_m2m_try_crop(ctx, &cr);
        if (ret)
                return ret;

        f = (cr.type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) ?
                &ctx->s_frame : &ctx->d_frame;

        /* Check to see if scaling ratio is within supported range */
        if (cr.type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
                ret = fimc_check_scaler_ratio(ctx, cr.c.width,
                                cr.c.height, ctx->d_frame.width,
                                ctx->d_frame.height, ctx->rotation);
        } else {
                ret = fimc_check_scaler_ratio(ctx, ctx->s_frame.width,
                                ctx->s_frame.height, cr.c.width,
                                cr.c.height, ctx->rotation);
        }
        if (ret) {
                v4l2_err(&fimc->m2m.vfd, "Out of scaler range\n");
                return -EINVAL;
        }

        f->offs_h = cr.c.left;
        f->offs_v = cr.c.top;
        f->width  = cr.c.width;
        f->height = cr.c.height;

        fimc_ctx_state_set(FIMC_PARAMS, ctx);

        return 0;
}

static const struct v4l2_ioctl_ops fimc_m2m_ioctl_ops = {
        .vidioc_querycap                = fimc_m2m_querycap,
        .vidioc_enum_fmt_vid_cap_mplane = fimc_m2m_enum_fmt_mplane,
        .vidioc_enum_fmt_vid_out_mplane = fimc_m2m_enum_fmt_mplane,
        .vidioc_g_fmt_vid_cap_mplane    = fimc_m2m_g_fmt_mplane,
        .vidioc_g_fmt_vid_out_mplane    = fimc_m2m_g_fmt_mplane,
        .vidioc_try_fmt_vid_cap_mplane  = fimc_m2m_try_fmt_mplane,
        .vidioc_try_fmt_vid_out_mplane  = fimc_m2m_try_fmt_mplane,
        .vidioc_s_fmt_vid_cap_mplane    = fimc_m2m_s_fmt_mplane,
        .vidioc_s_fmt_vid_out_mplane    = fimc_m2m_s_fmt_mplane,
        .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_expbuf                  = v4l2_m2m_ioctl_expbuf,
        .vidioc_streamon                = v4l2_m2m_ioctl_streamon,
        .vidioc_streamoff               = v4l2_m2m_ioctl_streamoff,
        .vidioc_g_crop                  = fimc_m2m_g_crop,
        .vidioc_s_crop                  = fimc_m2m_s_crop,
        .vidioc_cropcap                 = fimc_m2m_cropcap

};

static int queue_init(void *priv, struct vb2_queue *src_vq,
                      struct vb2_queue *dst_vq)
{
        struct fimc_ctx *ctx = priv;
        int ret;

        src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
        src_vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
        src_vq->drv_priv = ctx;
        src_vq->ops = &fimc_qops;
        src_vq->mem_ops = &vb2_dma_contig_memops;
        src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
        src_vq->timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_COPY;
        src_vq->lock = &ctx->fimc_dev->lock;

        ret = vb2_queue_init(src_vq);
        if (ret)
                return ret;

        dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
        dst_vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
        dst_vq->drv_priv = ctx;
        dst_vq->ops = &fimc_qops;
        dst_vq->mem_ops = &vb2_dma_contig_memops;
        dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
        dst_vq->timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_COPY;
        dst_vq->lock = &ctx->fimc_dev->lock;

        return vb2_queue_init(dst_vq);
}

static int fimc_m2m_set_default_format(struct fimc_ctx *ctx)
{
        struct v4l2_pix_format_mplane pixm = {
                .pixelformat    = V4L2_PIX_FMT_RGB32,
                .width          = 800,
                .height         = 600,
                .plane_fmt[0]   = {
                        .bytesperline = 800 * 4,
                        .sizeimage = 800 * 4 * 600,
                },
        };
        struct fimc_fmt *fmt;

        fmt = fimc_find_format(&pixm.pixelformat, NULL, FMT_FLAGS_M2M, 0);
        if (!fmt)
                return -EINVAL;

        __set_frame_format(&ctx->s_frame, fmt, &pixm);
        __set_frame_format(&ctx->d_frame, fmt, &pixm);

        return 0;
}

static int fimc_m2m_open(struct file *file)
{
        struct fimc_dev *fimc = video_drvdata(file);
        struct fimc_ctx *ctx;
        int ret = -EBUSY;

        pr_debug("pid: %d, state: %#lx\n", task_pid_nr(current), fimc->state);

        if (mutex_lock_interruptible(&fimc->lock))
                return -ERESTARTSYS;
        /*
         * Don't allow simultaneous open() of the mem-to-mem and the
         * capture video node that belong to same FIMC IP instance.
         */
        if (test_bit(ST_CAPT_BUSY, &fimc->state))
                goto unlock;

        ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
        if (!ctx) {
                ret = -ENOMEM;
                goto unlock;
        }
        v4l2_fh_init(&ctx->fh, &fimc->m2m.vfd);
        ctx->fimc_dev = fimc;

        /* Default color format */
        ctx->s_frame.fmt = fimc_get_format(0);
        ctx->d_frame.fmt = fimc_get_format(0);

        ret = fimc_ctrls_create(ctx);
        if (ret)
                goto error_fh;

        /* Use separate control handler per file handle */
        ctx->fh.ctrl_handler = &ctx->ctrls.handler;
        file->private_data = &ctx->fh;
        v4l2_fh_add(&ctx->fh);

        /* Setup the device context for memory-to-memory mode */
        ctx->state = FIMC_CTX_M2M;
        ctx->flags = 0;
        ctx->in_path = FIMC_IO_DMA;
        ctx->out_path = FIMC_IO_DMA;
        ctx->scaler.enabled = 1;

        ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(fimc->m2m.m2m_dev, ctx, queue_init);
        if (IS_ERR(ctx->fh.m2m_ctx)) {
                ret = PTR_ERR(ctx->fh.m2m_ctx);
                goto error_c;
        }

        if (fimc->m2m.refcnt++ == 0)
                set_bit(ST_M2M_RUN, &fimc->state);

        ret = fimc_m2m_set_default_format(ctx);
        if (ret < 0)
                goto error_m2m_ctx;

        mutex_unlock(&fimc->lock);
        return 0;

error_m2m_ctx:
        v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
error_c:
        fimc_ctrls_delete(ctx);
error_fh:
        v4l2_fh_del(&ctx->fh);
        v4l2_fh_exit(&ctx->fh);
        kfree(ctx);
unlock:
        mutex_unlock(&fimc->lock);
        return ret;
}

static int fimc_m2m_release(struct file *file)
{
        struct fimc_ctx *ctx = fh_to_ctx(file->private_data);
        struct fimc_dev *fimc = ctx->fimc_dev;

        dbg("pid: %d, state: 0x%lx, refcnt= %d",
                task_pid_nr(current), fimc->state, fimc->m2m.refcnt);

        mutex_lock(&fimc->lock);

        v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
        fimc_ctrls_delete(ctx);
        v4l2_fh_del(&ctx->fh);
        v4l2_fh_exit(&ctx->fh);

        if (--fimc->m2m.refcnt <= 0)
                clear_bit(ST_M2M_RUN, &fimc->state);
        kfree(ctx);

        mutex_unlock(&fimc->lock);
        return 0;
}

static const struct v4l2_file_operations fimc_m2m_fops = {
        .owner          = THIS_MODULE,
        .open           = fimc_m2m_open,
        .release        = fimc_m2m_release,
        .poll           = v4l2_m2m_fop_poll,
        .unlocked_ioctl = video_ioctl2,
        .mmap           = v4l2_m2m_fop_mmap,
};

static struct v4l2_m2m_ops m2m_ops = {
        .device_run     = fimc_device_run,
        .job_abort      = fimc_job_abort,
};

int fimc_register_m2m_device(struct fimc_dev *fimc,
                             struct v4l2_device *v4l2_dev)
{
        struct video_device *vfd = &fimc->m2m.vfd;
        int ret;

        fimc->v4l2_dev = v4l2_dev;

        memset(vfd, 0, sizeof(*vfd));
        vfd->fops = &fimc_m2m_fops;
        vfd->ioctl_ops = &fimc_m2m_ioctl_ops;
        vfd->v4l2_dev = v4l2_dev;
        vfd->minor = -1;
        vfd->release = video_device_release_empty;
        vfd->lock = &fimc->lock;
        vfd->vfl_dir = VFL_DIR_M2M;

        snprintf(vfd->name, sizeof(vfd->name), "fimc.%d.m2m", fimc->id);
        video_set_drvdata(vfd, fimc);

        fimc->m2m.m2m_dev = v4l2_m2m_init(&m2m_ops);
        if (IS_ERR(fimc->m2m.m2m_dev)) {
                v4l2_err(v4l2_dev, "failed to initialize v4l2-m2m device\n");
                return PTR_ERR(fimc->m2m.m2m_dev);
        }

        ret = media_entity_init(&vfd->entity, 0, NULL, 0);
        if (ret)
                goto err_me;

        ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
        if (ret)
                goto err_vd;

        v4l2_info(v4l2_dev, "Registered %s as /dev/%s\n",
                  vfd->name, video_device_node_name(vfd));
        return 0;

err_vd:
        media_entity_cleanup(&vfd->entity);
err_me:
        v4l2_m2m_release(fimc->m2m.m2m_dev);
        return ret;
}

void fimc_unregister_m2m_device(struct fimc_dev *fimc)
{
        if (!fimc)
                return;

        if (fimc->m2m.m2m_dev)
                v4l2_m2m_release(fimc->m2m.m2m_dev);

        if (video_is_registered(&fimc->m2m.vfd)) {
                video_unregister_device(&fimc->m2m.vfd);
                media_entity_cleanup(&fimc->m2m.vfd.entity);
        }
}