// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2010-2013 Bluecherry, LLC <https://www.bluecherrydvr.com>
 *
 * Original author:
 * Ben Collins <bcollins@ubuntu.com>
 *
 * Additional work by:
 * John Brooks <john.brooks@bluecherry.net>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/freezer.h>

#include <media/v4l2-ioctl.h>
#include <media/v4l2-common.h>
#include <media/v4l2-event.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-dma-contig.h>

#include "solo6x10.h"
#include "solo6x10-tw28.h"

/* Image size is two fields, SOLO_HW_BPL is one horizontal line in hardware */
#define SOLO_HW_BPL             2048
#define solo_vlines(__solo)     (__solo->video_vsize * 2)
#define solo_image_size(__solo) (solo_bytesperline(__solo) * \
                                 solo_vlines(__solo))
#define solo_bytesperline(__solo) (__solo->video_hsize * 2)

#define MIN_VID_BUFFERS         2

static inline void erase_on(struct solo_dev *solo_dev)
{
        solo_reg_write(solo_dev, SOLO_VO_DISP_ERASE, SOLO_VO_DISP_ERASE_ON);
        solo_dev->erasing = 1;
        solo_dev->frame_blank = 0;
}

static inline int erase_off(struct solo_dev *solo_dev)
{
        if (!solo_dev->erasing)
                return 0;

        /* First time around, assert erase off */
        if (!solo_dev->frame_blank)
                solo_reg_write(solo_dev, SOLO_VO_DISP_ERASE, 0);
        /* Keep the erasing flag on for 8 frames minimum */
        if (solo_dev->frame_blank++ >= 8)
                solo_dev->erasing = 0;

        return 1;
}

void solo_video_in_isr(struct solo_dev *solo_dev)
{
        wake_up_interruptible_all(&solo_dev->disp_thread_wait);
}

static void solo_win_setup(struct solo_dev *solo_dev, u8 ch,
                           int sx, int sy, int ex, int ey, int scale)
{
        if (ch >= solo_dev->nr_chans)
                return;

        /* Here, we just keep window/channel the same */
        solo_reg_write(solo_dev, SOLO_VI_WIN_CTRL0(ch),
                       SOLO_VI_WIN_CHANNEL(ch) |
                       SOLO_VI_WIN_SX(sx) |
                       SOLO_VI_WIN_EX(ex) |
                       SOLO_VI_WIN_SCALE(scale));

        solo_reg_write(solo_dev, SOLO_VI_WIN_CTRL1(ch),
                       SOLO_VI_WIN_SY(sy) |
                       SOLO_VI_WIN_EY(ey));
}

static int solo_v4l2_ch_ext_4up(struct solo_dev *solo_dev, u8 idx, int on)
{
        u8 ch = idx * 4;

        if (ch >= solo_dev->nr_chans)
                return -EINVAL;

        if (!on) {
                u8 i;

                for (i = ch; i < ch + 4; i++)
                        solo_win_setup(solo_dev, i, solo_dev->video_hsize,
                                       solo_vlines(solo_dev),
                                       solo_dev->video_hsize,
                                       solo_vlines(solo_dev), 0);
                return 0;
        }

        /* Row 1 */
        solo_win_setup(solo_dev, ch, 0, 0, solo_dev->video_hsize / 2,
                       solo_vlines(solo_dev) / 2, 3);
        solo_win_setup(solo_dev, ch + 1, solo_dev->video_hsize / 2, 0,
                       solo_dev->video_hsize, solo_vlines(solo_dev) / 2, 3);
        /* Row 2 */
        solo_win_setup(solo_dev, ch + 2, 0, solo_vlines(solo_dev) / 2,
                       solo_dev->video_hsize / 2, solo_vlines(solo_dev), 3);
        solo_win_setup(solo_dev, ch + 3, solo_dev->video_hsize / 2,
                       solo_vlines(solo_dev) / 2, solo_dev->video_hsize,
                       solo_vlines(solo_dev), 3);

        return 0;
}

static int solo_v4l2_ch_ext_16up(struct solo_dev *solo_dev, int on)
{
        int sy, ysize, hsize, i;

        if (!on) {
                for (i = 0; i < 16; i++)
                        solo_win_setup(solo_dev, i, solo_dev->video_hsize,
                                       solo_vlines(solo_dev),
                                       solo_dev->video_hsize,
                                       solo_vlines(solo_dev), 0);
                return 0;
        }

        ysize = solo_vlines(solo_dev) / 4;
        hsize = solo_dev->video_hsize / 4;

        for (sy = 0, i = 0; i < 4; i++, sy += ysize) {
                solo_win_setup(solo_dev, i * 4, 0, sy, hsize,
                               sy + ysize, 5);
                solo_win_setup(solo_dev, (i * 4) + 1, hsize, sy,
                               hsize * 2, sy + ysize, 5);
                solo_win_setup(solo_dev, (i * 4) + 2, hsize * 2, sy,
                               hsize * 3, sy + ysize, 5);
                solo_win_setup(solo_dev, (i * 4) + 3, hsize * 3, sy,
                               solo_dev->video_hsize, sy + ysize, 5);
        }

        return 0;
}

static int solo_v4l2_ch(struct solo_dev *solo_dev, u8 ch, int on)
{
        u8 ext_ch;

        if (ch < solo_dev->nr_chans) {
                solo_win_setup(solo_dev, ch, on ? 0 : solo_dev->video_hsize,
                               on ? 0 : solo_vlines(solo_dev),
                               solo_dev->video_hsize, solo_vlines(solo_dev),
                               on ? 1 : 0);
                return 0;
        }

        if (ch >= solo_dev->nr_chans + solo_dev->nr_ext)
                return -EINVAL;

        ext_ch = ch - solo_dev->nr_chans;

        /* 4up's first */
        if (ext_ch < 4)
                return solo_v4l2_ch_ext_4up(solo_dev, ext_ch, on);

        /* Remaining case is 16up for 16-port */
        return solo_v4l2_ch_ext_16up(solo_dev, on);
}

static int solo_v4l2_set_ch(struct solo_dev *solo_dev, u8 ch)
{
        if (ch >= solo_dev->nr_chans + solo_dev->nr_ext)
                return -EINVAL;

        erase_on(solo_dev);

        solo_v4l2_ch(solo_dev, solo_dev->cur_disp_ch, 0);
        solo_v4l2_ch(solo_dev, ch, 1);

        solo_dev->cur_disp_ch = ch;

        return 0;
}

static void solo_fillbuf(struct solo_dev *solo_dev,
                         struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        dma_addr_t addr;
        unsigned int fdma_addr;
        int error = -1;
        int i;

        addr = vb2_dma_contig_plane_dma_addr(vb, 0);
        if (!addr)
                goto finish_buf;

        if (erase_off(solo_dev)) {
                void *p = vb2_plane_vaddr(vb, 0);
                int image_size = solo_image_size(solo_dev);

                for (i = 0; i < image_size; i += 2) {
                        ((u8 *)p)[i] = 0x80;
                        ((u8 *)p)[i + 1] = 0x00;
                }
                error = 0;
        } else {
                fdma_addr = SOLO_DISP_EXT_ADDR + (solo_dev->old_write *
                                (SOLO_HW_BPL * solo_vlines(solo_dev)));

                error = solo_p2m_dma_t(solo_dev, 0, addr, fdma_addr,
                                       solo_bytesperline(solo_dev),
                                       solo_vlines(solo_dev), SOLO_HW_BPL);
        }

finish_buf:
        if (!error) {
                vb2_set_plane_payload(vb, 0,
                        solo_vlines(solo_dev) * solo_bytesperline(solo_dev));
                vbuf->sequence = solo_dev->sequence++;
                vb->timestamp = ktime_get_ns();
        }

        vb2_buffer_done(vb, error ? VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
}

static void solo_thread_try(struct solo_dev *solo_dev)
{
        struct solo_vb2_buf *vb;

        /* Only "break" from this loop if slock is held, otherwise
         * just return. */
        for (;;) {
                unsigned int cur_write;

                cur_write = SOLO_VI_STATUS0_PAGE(
                        solo_reg_read(solo_dev, SOLO_VI_STATUS0));
                if (cur_write == solo_dev->old_write)
                        return;

                spin_lock(&solo_dev->slock);

                if (list_empty(&solo_dev->vidq_active))
                        break;

                vb = list_first_entry(&solo_dev->vidq_active, struct solo_vb2_buf,
                                      list);

                solo_dev->old_write = cur_write;
                list_del(&vb->list);

                spin_unlock(&solo_dev->slock);

                solo_fillbuf(solo_dev, &vb->vb.vb2_buf);
        }

        assert_spin_locked(&solo_dev->slock);
        spin_unlock(&solo_dev->slock);
}

static int solo_thread(void *data)
{
        struct solo_dev *solo_dev = data;
        DECLARE_WAITQUEUE(wait, current);

        set_freezable();
        add_wait_queue(&solo_dev->disp_thread_wait, &wait);

        for (;;) {
                long timeout = schedule_timeout_interruptible(HZ);

                if (timeout == -ERESTARTSYS || kthread_should_stop())
                        break;
                solo_thread_try(solo_dev);
                try_to_freeze();
        }

        remove_wait_queue(&solo_dev->disp_thread_wait, &wait);

        return 0;
}

static int solo_start_thread(struct solo_dev *solo_dev)
{
        int ret = 0;

        solo_dev->kthread = kthread_run(solo_thread, solo_dev, SOLO6X10_NAME "_disp");

        if (IS_ERR(solo_dev->kthread)) {
                ret = PTR_ERR(solo_dev->kthread);
                solo_dev->kthread = NULL;
                return ret;
        }
        solo_irq_on(solo_dev, SOLO_IRQ_VIDEO_IN);

        return ret;
}

static void solo_stop_thread(struct solo_dev *solo_dev)
{
        if (!solo_dev->kthread)
                return;

        solo_irq_off(solo_dev, SOLO_IRQ_VIDEO_IN);
        kthread_stop(solo_dev->kthread);
        solo_dev->kthread = NULL;
}

static int solo_queue_setup(struct vb2_queue *q,
                           unsigned int *num_buffers, unsigned int *num_planes,
                           unsigned int sizes[], struct device *alloc_devs[])
{
        struct solo_dev *solo_dev = vb2_get_drv_priv(q);

        sizes[0] = solo_image_size(solo_dev);
        *num_planes = 1;

        if (*num_buffers < MIN_VID_BUFFERS)
                *num_buffers = MIN_VID_BUFFERS;

        return 0;
}

static int solo_start_streaming(struct vb2_queue *q, unsigned int count)
{
        struct solo_dev *solo_dev = vb2_get_drv_priv(q);

        solo_dev->sequence = 0;
        return solo_start_thread(solo_dev);
}

static void solo_stop_streaming(struct vb2_queue *q)
{
        struct solo_dev *solo_dev = vb2_get_drv_priv(q);

        solo_stop_thread(solo_dev);

        spin_lock(&solo_dev->slock);
        while (!list_empty(&solo_dev->vidq_active)) {
                struct solo_vb2_buf *buf = list_entry(
                                solo_dev->vidq_active.next,
                                struct solo_vb2_buf, list);

                list_del(&buf->list);
                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
        }
        spin_unlock(&solo_dev->slock);
        INIT_LIST_HEAD(&solo_dev->vidq_active);
}

static void solo_buf_queue(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct vb2_queue *vq = vb->vb2_queue;
        struct solo_dev *solo_dev = vb2_get_drv_priv(vq);
        struct solo_vb2_buf *solo_vb =
                container_of(vbuf, struct solo_vb2_buf, vb);

        spin_lock(&solo_dev->slock);
        list_add_tail(&solo_vb->list, &solo_dev->vidq_active);
        spin_unlock(&solo_dev->slock);
        wake_up_interruptible(&solo_dev->disp_thread_wait);
}

static const struct vb2_ops solo_video_qops = {
        .queue_setup    = solo_queue_setup,
        .buf_queue      = solo_buf_queue,
        .start_streaming = solo_start_streaming,
        .stop_streaming = solo_stop_streaming,
};

static int solo_querycap(struct file *file, void  *priv,
                         struct v4l2_capability *cap)
{
        strscpy(cap->driver, SOLO6X10_NAME, sizeof(cap->driver));
        strscpy(cap->card, "Softlogic 6x10", sizeof(cap->card));
        return 0;
}

static int solo_enum_ext_input(struct solo_dev *solo_dev,
                               struct v4l2_input *input)
{
        int ext = input->index - solo_dev->nr_chans;
        unsigned int nup, first;

        if (ext >= solo_dev->nr_ext)
                return -EINVAL;

        nup   = (ext == 4) ? 16 : 4;
        first = (ext & 3) << 2; /* first channel in the n-up */
        snprintf(input->name, sizeof(input->name),
                 "Multi %d-up (cameras %d-%d)",
                 nup, first + 1, first + nup);
        /* Possible outputs:
         *  Multi 4-up (cameras 1-4)
         *  Multi 4-up (cameras 5-8)
         *  Multi 4-up (cameras 9-12)
         *  Multi 4-up (cameras 13-16)
         *  Multi 16-up (cameras 1-16)
         */
        return 0;
}

static int solo_enum_input(struct file *file, void *priv,
                           struct v4l2_input *input)
{
        struct solo_dev *solo_dev = video_drvdata(file);

        if (input->index >= solo_dev->nr_chans) {
                int ret = solo_enum_ext_input(solo_dev, input);

                if (ret < 0)
                        return ret;
        } else {
                snprintf(input->name, sizeof(input->name), "Camera %d",
                         input->index + 1);

                /* We can only check this for normal inputs */
                if (!tw28_get_video_status(solo_dev, input->index))
                        input->status = V4L2_IN_ST_NO_SIGNAL;
        }

        input->type = V4L2_INPUT_TYPE_CAMERA;
        input->std = solo_dev->vfd->tvnorms;
        return 0;
}

static int solo_set_input(struct file *file, void *priv, unsigned int index)
{
        struct solo_dev *solo_dev = video_drvdata(file);
        int ret = solo_v4l2_set_ch(solo_dev, index);

        if (!ret) {
                while (erase_off(solo_dev))
                        /* Do nothing */;
        }

        return ret;
}

static int solo_get_input(struct file *file, void *priv, unsigned int *index)
{
        struct solo_dev *solo_dev = video_drvdata(file);

        *index = solo_dev->cur_disp_ch;

        return 0;
}

static int solo_enum_fmt_cap(struct file *file, void *priv,
                             struct v4l2_fmtdesc *f)
{
        if (f->index)
                return -EINVAL;

        f->pixelformat = V4L2_PIX_FMT_UYVY;
        return 0;
}

static int solo_try_fmt_cap(struct file *file, void *priv,
                            struct v4l2_format *f)
{
        struct solo_dev *solo_dev = video_drvdata(file);
        struct v4l2_pix_format *pix = &f->fmt.pix;
        int image_size = solo_image_size(solo_dev);

        if (pix->pixelformat != V4L2_PIX_FMT_UYVY)
                return -EINVAL;

        pix->width = solo_dev->video_hsize;
        pix->height = solo_vlines(solo_dev);
        pix->sizeimage = image_size;
        pix->field = V4L2_FIELD_INTERLACED;
        pix->pixelformat = V4L2_PIX_FMT_UYVY;
        pix->colorspace = V4L2_COLORSPACE_SMPTE170M;
        return 0;
}

static int solo_set_fmt_cap(struct file *file, void *priv,
                            struct v4l2_format *f)
{
        struct solo_dev *solo_dev = video_drvdata(file);

        if (vb2_is_busy(&solo_dev->vidq))
                return -EBUSY;

        /* For right now, if it doesn't match our running config,
         * then fail */
        return solo_try_fmt_cap(file, priv, f);
}

static int solo_get_fmt_cap(struct file *file, void *priv,
                            struct v4l2_format *f)
{
        struct solo_dev *solo_dev = video_drvdata(file);
        struct v4l2_pix_format *pix = &f->fmt.pix;

        pix->width = solo_dev->video_hsize;
        pix->height = solo_vlines(solo_dev);
        pix->pixelformat = V4L2_PIX_FMT_UYVY;
        pix->field = V4L2_FIELD_INTERLACED;
        pix->sizeimage = solo_image_size(solo_dev);
        pix->colorspace = V4L2_COLORSPACE_SMPTE170M;
        pix->bytesperline = solo_bytesperline(solo_dev);

        return 0;
}

static int solo_g_std(struct file *file, void *priv, v4l2_std_id *i)
{
        struct solo_dev *solo_dev = video_drvdata(file);

        if (solo_dev->video_type == SOLO_VO_FMT_TYPE_NTSC)
                *i = V4L2_STD_NTSC_M;
        else
                *i = V4L2_STD_PAL;
        return 0;
}

int solo_set_video_type(struct solo_dev *solo_dev, bool is_50hz)
{
        int i;

        /* Make sure all video nodes are idle */
        if (vb2_is_busy(&solo_dev->vidq))
                return -EBUSY;
        for (i = 0; i < solo_dev->nr_chans; i++)
                if (vb2_is_busy(&solo_dev->v4l2_enc[i]->vidq))
                        return -EBUSY;
        solo_dev->video_type = is_50hz ? SOLO_VO_FMT_TYPE_PAL :
                                         SOLO_VO_FMT_TYPE_NTSC;
        /* Reconfigure for the new standard */
        solo_disp_init(solo_dev);
        solo_enc_init(solo_dev);
        solo_tw28_init(solo_dev);
        for (i = 0; i < solo_dev->nr_chans; i++)
                solo_update_mode(solo_dev->v4l2_enc[i]);
        return solo_v4l2_set_ch(solo_dev, solo_dev->cur_disp_ch);
}

static int solo_s_std(struct file *file, void *priv, v4l2_std_id std)
{
        struct solo_dev *solo_dev = video_drvdata(file);

        return solo_set_video_type(solo_dev, std & V4L2_STD_625_50);
}

static int solo_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct solo_dev *solo_dev =
                container_of(ctrl->handler, struct solo_dev, disp_hdl);

        switch (ctrl->id) {
        case V4L2_CID_MOTION_TRACE:
                if (ctrl->val) {
                        solo_reg_write(solo_dev, SOLO_VI_MOTION_BORDER,
                                        SOLO_VI_MOTION_Y_ADD |
                                        SOLO_VI_MOTION_Y_VALUE(0x20) |
                                        SOLO_VI_MOTION_CB_VALUE(0x10) |
                                        SOLO_VI_MOTION_CR_VALUE(0x10));
                        solo_reg_write(solo_dev, SOLO_VI_MOTION_BAR,
                                        SOLO_VI_MOTION_CR_ADD |
                                        SOLO_VI_MOTION_Y_VALUE(0x10) |
                                        SOLO_VI_MOTION_CB_VALUE(0x80) |
                                        SOLO_VI_MOTION_CR_VALUE(0x10));
                } else {
                        solo_reg_write(solo_dev, SOLO_VI_MOTION_BORDER, 0);
                        solo_reg_write(solo_dev, SOLO_VI_MOTION_BAR, 0);
                }
                return 0;
        default:
                break;
        }
        return -EINVAL;
}

static const struct v4l2_file_operations solo_v4l2_fops = {
        .owner                  = THIS_MODULE,
        .open                   = v4l2_fh_open,
        .release                = vb2_fop_release,
        .read                   = vb2_fop_read,
        .poll                   = vb2_fop_poll,
        .mmap                   = vb2_fop_mmap,
        .unlocked_ioctl         = video_ioctl2,
};

static const struct v4l2_ioctl_ops solo_v4l2_ioctl_ops = {
        .vidioc_querycap                = solo_querycap,
        .vidioc_s_std                   = solo_s_std,
        .vidioc_g_std                   = solo_g_std,
        /* Input callbacks */
        .vidioc_enum_input              = solo_enum_input,
        .vidioc_s_input                 = solo_set_input,
        .vidioc_g_input                 = solo_get_input,
        /* Video capture format callbacks */
        .vidioc_enum_fmt_vid_cap        = solo_enum_fmt_cap,
        .vidioc_try_fmt_vid_cap         = solo_try_fmt_cap,
        .vidioc_s_fmt_vid_cap           = solo_set_fmt_cap,
        .vidioc_g_fmt_vid_cap           = solo_get_fmt_cap,
        /* Streaming I/O */
        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
        .vidioc_querybuf                = vb2_ioctl_querybuf,
        .vidioc_qbuf                    = vb2_ioctl_qbuf,
        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,
        /* Logging and events */
        .vidioc_log_status              = v4l2_ctrl_log_status,
        .vidioc_subscribe_event         = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event       = v4l2_event_unsubscribe,
};

static const struct video_device solo_v4l2_template = {
        .name                   = SOLO6X10_NAME,
        .fops                   = &solo_v4l2_fops,
        .ioctl_ops              = &solo_v4l2_ioctl_ops,
        .minor                  = -1,
        .release                = video_device_release,
        .tvnorms                = V4L2_STD_NTSC_M | V4L2_STD_PAL,
        .device_caps            = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
                                  V4L2_CAP_STREAMING,
};

static const struct v4l2_ctrl_ops solo_ctrl_ops = {
        .s_ctrl = solo_s_ctrl,
};

static const struct v4l2_ctrl_config solo_motion_trace_ctrl = {
        .ops = &solo_ctrl_ops,
        .id = V4L2_CID_MOTION_TRACE,
        .name = "Motion Detection Trace",
        .type = V4L2_CTRL_TYPE_BOOLEAN,
        .max = 1,
        .step = 1,
};

int solo_v4l2_init(struct solo_dev *solo_dev, unsigned nr)
{
        int ret;
        int i;

        init_waitqueue_head(&solo_dev->disp_thread_wait);
        spin_lock_init(&solo_dev->slock);
        mutex_init(&solo_dev->lock);
        INIT_LIST_HEAD(&solo_dev->vidq_active);

        solo_dev->vfd = video_device_alloc();
        if (!solo_dev->vfd)
                return -ENOMEM;

        *solo_dev->vfd = solo_v4l2_template;
        solo_dev->vfd->v4l2_dev = &solo_dev->v4l2_dev;
        solo_dev->vfd->queue = &solo_dev->vidq;
        solo_dev->vfd->lock = &solo_dev->lock;
        v4l2_ctrl_handler_init(&solo_dev->disp_hdl, 1);
        v4l2_ctrl_new_custom(&solo_dev->disp_hdl, &solo_motion_trace_ctrl, NULL);
        if (solo_dev->disp_hdl.error) {
                ret = solo_dev->disp_hdl.error;
                goto fail;
        }
        solo_dev->vfd->ctrl_handler = &solo_dev->disp_hdl;

        video_set_drvdata(solo_dev->vfd, solo_dev);

        solo_dev->vidq.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        solo_dev->vidq.io_modes = VB2_MMAP | VB2_USERPTR | VB2_READ;
        solo_dev->vidq.ops = &solo_video_qops;
        solo_dev->vidq.mem_ops = &vb2_dma_contig_memops;
        solo_dev->vidq.drv_priv = solo_dev;
        solo_dev->vidq.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        solo_dev->vidq.gfp_flags = __GFP_DMA32 | __GFP_KSWAPD_RECLAIM;
        solo_dev->vidq.buf_struct_size = sizeof(struct solo_vb2_buf);
        solo_dev->vidq.lock = &solo_dev->lock;
        solo_dev->vidq.dev = &solo_dev->pdev->dev;
        ret = vb2_queue_init(&solo_dev->vidq);
        if (ret < 0)
                goto fail;

        /* Cycle all the channels and clear */
        for (i = 0; i < solo_dev->nr_chans; i++) {
                solo_v4l2_set_ch(solo_dev, i);
                while (erase_off(solo_dev))
                        /* Do nothing */;
        }

        /* Set the default display channel */
        solo_v4l2_set_ch(solo_dev, 0);
        while (erase_off(solo_dev))
                /* Do nothing */;

        ret = video_register_device(solo_dev->vfd, VFL_TYPE_VIDEO, nr);
        if (ret < 0)
                goto fail;

        snprintf(solo_dev->vfd->name, sizeof(solo_dev->vfd->name), "%s (%i)",
                 SOLO6X10_NAME, solo_dev->vfd->num);

        dev_info(&solo_dev->pdev->dev, "Display as /dev/video%d with %d inputs (%d extended)\n",
                 solo_dev->vfd->num,
                 solo_dev->nr_chans, solo_dev->nr_ext);

        return 0;

fail:
        video_device_release(solo_dev->vfd);
        v4l2_ctrl_handler_free(&solo_dev->disp_hdl);
        solo_dev->vfd = NULL;
        return ret;
}

void solo_v4l2_exit(struct solo_dev *solo_dev)
{
        if (solo_dev->vfd == NULL)
                return;

        video_unregister_device(solo_dev->vfd);
        v4l2_ctrl_handler_free(&solo_dev->disp_hdl);
        solo_dev->vfd = NULL;
}