/*
 *  Driver for the Conexant CX25821 PCIe bridge
 *
 *  Copyright (C) 2009 Conexant Systems Inc.
 *  Authors  <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
 *  Based on Steven Toth <stoth@linuxtv.org> cx23885 driver
 *  Parts adapted/taken from Eduardo Moscoso Rubino
 *  Copyright (C) 2009 Eduardo Moscoso Rubino <moscoso@TopoLogica.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.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "cx25821-video.h"

MODULE_DESCRIPTION("v4l2 driver module for cx25821 based TV cards");
MODULE_AUTHOR("Hiep Huynh <hiep.huynh@conexant.com>");
MODULE_LICENSE("GPL");

static unsigned int video_nr[] = {[0 ... (CX25821_MAXBOARDS - 1)] = UNSET };

module_param_array(video_nr, int, NULL, 0444);

MODULE_PARM_DESC(video_nr, "video device numbers");

static unsigned int video_debug = VIDEO_DEBUG;
module_param(video_debug, int, 0644);
MODULE_PARM_DESC(video_debug, "enable debug messages [video]");

static unsigned int irq_debug;
module_param(irq_debug, int, 0644);
MODULE_PARM_DESC(irq_debug, "enable debug messages [IRQ handler]");

static unsigned int vid_limit = 16;
module_param(vid_limit, int, 0644);
MODULE_PARM_DESC(vid_limit, "capture memory limit in megabytes");

#define FORMAT_FLAGS_PACKED       0x01

static const struct cx25821_fmt formats[] = {
        {
                .name = "4:1:1, packed, Y41P",
                .fourcc = V4L2_PIX_FMT_Y41P,
                .depth = 12,
                .flags = FORMAT_FLAGS_PACKED,
        }, {
                .name = "4:2:2, packed, YUYV",
                .fourcc = V4L2_PIX_FMT_YUYV,
                .depth = 16,
                .flags = FORMAT_FLAGS_PACKED,
        },
};

static const struct cx25821_fmt *cx25821_format_by_fourcc(unsigned int fourcc)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(formats); i++)
                if (formats[i].fourcc == fourcc)
                        return formats + i;
        return NULL;
}

void cx25821_video_wakeup(struct cx25821_dev *dev, struct cx25821_dmaqueue *q,
                          u32 count)
{
        struct cx25821_buffer *buf;
        int bc;

        for (bc = 0;; bc++) {
                if (list_empty(&q->active)) {
                        dprintk(1, "bc=%d (=0: active empty)\n", bc);
                        break;
                }

                buf = list_entry(q->active.next, struct cx25821_buffer,
                                vb.queue);

                /* count comes from the hw and it is 16bit wide --
                 * this trick handles wrap-arounds correctly for
                 * up to 32767 buffers in flight... */
                if ((s16) (count - buf->count) < 0)
                        break;

                v4l2_get_timestamp(&buf->vb.ts);
                buf->vb.state = VIDEOBUF_DONE;
                list_del(&buf->vb.queue);
                wake_up(&buf->vb.done);
        }

        if (list_empty(&q->active))
                del_timer(&q->timeout);
        else
                mod_timer(&q->timeout, jiffies + BUFFER_TIMEOUT);
        if (bc != 1)
                pr_err("%s: %d buffers handled (should be 1)\n", __func__, bc);
}

int cx25821_start_video_dma(struct cx25821_dev *dev,
                            struct cx25821_dmaqueue *q,
                            struct cx25821_buffer *buf,
                            const struct sram_channel *channel)
{
        int tmp = 0;

        /* setup fifo + format */
        cx25821_sram_channel_setup(dev, channel, buf->bpl, buf->risc.dma);

        /* reset counter */
        cx_write(channel->gpcnt_ctl, 3);
        q->count = 1;

        /* enable irq */
        cx_set(PCI_INT_MSK, cx_read(PCI_INT_MSK) | (1 << channel->i));
        cx_set(channel->int_msk, 0x11);

        /* start dma */
        cx_write(channel->dma_ctl, 0x11);       /* FIFO and RISC enable */

        /* make sure upstream setting if any is reversed */
        tmp = cx_read(VID_CH_MODE_SEL);
        cx_write(VID_CH_MODE_SEL, tmp & 0xFFFFFE00);

        return 0;
}

static int cx25821_restart_video_queue(struct cx25821_dev *dev,
                                       struct cx25821_dmaqueue *q,
                                       const struct sram_channel *channel)
{
        struct cx25821_buffer *buf, *prev;
        struct list_head *item;

        if (!list_empty(&q->active)) {
                buf = list_entry(q->active.next, struct cx25821_buffer,
                                vb.queue);

                cx25821_start_video_dma(dev, q, buf, channel);

                list_for_each(item, &q->active) {
                        buf = list_entry(item, struct cx25821_buffer, vb.queue);
                        buf->count = q->count++;
                }

                mod_timer(&q->timeout, jiffies + BUFFER_TIMEOUT);
                return 0;
        }

        prev = NULL;
        for (;;) {
                if (list_empty(&q->queued))
                        return 0;

                buf = list_entry(q->queued.next, struct cx25821_buffer,
                                vb.queue);

                if (NULL == prev) {
                        list_move_tail(&buf->vb.queue, &q->active);
                        cx25821_start_video_dma(dev, q, buf, channel);
                        buf->vb.state = VIDEOBUF_ACTIVE;
                        buf->count = q->count++;
                        mod_timer(&q->timeout, jiffies + BUFFER_TIMEOUT);
                } else if (prev->vb.width == buf->vb.width &&
                           prev->vb.height == buf->vb.height &&
                           prev->fmt == buf->fmt) {
                        list_move_tail(&buf->vb.queue, &q->active);
                        buf->vb.state = VIDEOBUF_ACTIVE;
                        buf->count = q->count++;
                        prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
                        prev->risc.jmp[2] = cpu_to_le32(0); /* Bits 63 - 32 */
                } else {
                        return 0;
                }
                prev = buf;
        }
}

static void cx25821_vid_timeout(unsigned long data)
{
        struct cx25821_data *timeout_data = (struct cx25821_data *)data;
        struct cx25821_dev *dev = timeout_data->dev;
        const struct sram_channel *channel = timeout_data->channel;
        struct cx25821_dmaqueue *q = &dev->channels[channel->i].dma_vidq;
        struct cx25821_buffer *buf;
        unsigned long flags;

        /* cx25821_sram_channel_dump(dev, channel); */
        cx_clear(channel->dma_ctl, 0x11);

        spin_lock_irqsave(&dev->slock, flags);
        while (!list_empty(&q->active)) {
                buf = list_entry(q->active.next, struct cx25821_buffer,
                                vb.queue);
                list_del(&buf->vb.queue);

                buf->vb.state = VIDEOBUF_ERROR;
                wake_up(&buf->vb.done);
        }

        cx25821_restart_video_queue(dev, q, channel);
        spin_unlock_irqrestore(&dev->slock, flags);
}

int cx25821_video_irq(struct cx25821_dev *dev, int chan_num, u32 status)
{
        u32 count = 0;
        int handled = 0;
        u32 mask;
        const struct sram_channel *channel = dev->channels[chan_num].sram_channels;

        mask = cx_read(channel->int_msk);
        if (0 == (status & mask))
                return handled;

        cx_write(channel->int_stat, status);

        /* risc op code error */
        if (status & (1 << 16)) {
                pr_warn("%s, %s: video risc op code error\n",
                        dev->name, channel->name);
                cx_clear(channel->dma_ctl, 0x11);
                cx25821_sram_channel_dump(dev, channel);
        }

        /* risc1 y */
        if (status & FLD_VID_DST_RISC1) {
                spin_lock(&dev->slock);
                count = cx_read(channel->gpcnt);
                cx25821_video_wakeup(dev, &dev->channels[channel->i].dma_vidq,
                                count);
                spin_unlock(&dev->slock);
                handled++;
        }

        /* risc2 y */
        if (status & 0x10) {
                dprintk(2, "stopper video\n");
                spin_lock(&dev->slock);
                cx25821_restart_video_queue(dev,
                                &dev->channels[channel->i].dma_vidq, channel);
                spin_unlock(&dev->slock);
                handled++;
        }
        return handled;
}

static int cx25821_buffer_setup(struct videobuf_queue *q, unsigned int *count,
                 unsigned int *size)
{
        struct cx25821_channel *chan = q->priv_data;

        *size = chan->fmt->depth * chan->width * chan->height >> 3;

        if (0 == *count)
                *count = 32;

        if (*size * *count > vid_limit * 1024 * 1024)
                *count = (vid_limit * 1024 * 1024) / *size;

        return 0;
}

static int cx25821_buffer_prepare(struct videobuf_queue *q, struct videobuf_buffer *vb,
                   enum v4l2_field field)
{
        struct cx25821_channel *chan = q->priv_data;
        struct cx25821_dev *dev = chan->dev;
        struct cx25821_buffer *buf =
                container_of(vb, struct cx25821_buffer, vb);
        int rc, init_buffer = 0;
        u32 line0_offset;
        struct videobuf_dmabuf *dma = videobuf_to_dma(&buf->vb);
        int bpl_local = LINE_SIZE_D1;

        BUG_ON(NULL == chan->fmt);
        if (chan->width < 48 || chan->width > 720 ||
            chan->height < 32 || chan->height > 576)
                return -EINVAL;

        buf->vb.size = (chan->width * chan->height * chan->fmt->depth) >> 3;

        if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size)
                return -EINVAL;

        if (buf->fmt != chan->fmt ||
            buf->vb.width != chan->width ||
            buf->vb.height != chan->height || buf->vb.field != field) {
                buf->fmt = chan->fmt;
                buf->vb.width = chan->width;
                buf->vb.height = chan->height;
                buf->vb.field = field;
                init_buffer = 1;
        }

        if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
                init_buffer = 1;
                rc = videobuf_iolock(q, &buf->vb, NULL);
                if (0 != rc) {
                        printk(KERN_DEBUG pr_fmt("videobuf_iolock failed!\n"));
                        goto fail;
                }
        }

        dprintk(1, "init_buffer=%d\n", init_buffer);

        if (init_buffer) {
                if (chan->pixel_formats == PIXEL_FRMT_411)
                        buf->bpl = (buf->fmt->depth * buf->vb.width) >> 3;
                else
                        buf->bpl = (buf->fmt->depth >> 3) * (buf->vb.width);

                if (chan->pixel_formats == PIXEL_FRMT_411) {
                        bpl_local = buf->bpl;
                } else {
                        bpl_local = buf->bpl;   /* Default */

                        if (chan->use_cif_resolution) {
                                if (dev->tvnorm & V4L2_STD_625_50)
                                        bpl_local = 352 << 1;
                                else
                                        bpl_local = chan->cif_width << 1;
                        }
                }

                switch (buf->vb.field) {
                case V4L2_FIELD_TOP:
                        cx25821_risc_buffer(dev->pci, &buf->risc,
                                            dma->sglist, 0, UNSET,
                                            buf->bpl, 0, buf->vb.height);
                        break;
                case V4L2_FIELD_BOTTOM:
                        cx25821_risc_buffer(dev->pci, &buf->risc,
                                            dma->sglist, UNSET, 0,
                                            buf->bpl, 0, buf->vb.height);
                        break;
                case V4L2_FIELD_INTERLACED:
                        /* All other formats are top field first */
                        line0_offset = 0;
                        dprintk(1, "top field first\n");

                        cx25821_risc_buffer(dev->pci, &buf->risc,
                                            dma->sglist, line0_offset,
                                            bpl_local, bpl_local, bpl_local,
                                            buf->vb.height >> 1);
                        break;
                case V4L2_FIELD_SEQ_TB:
                        cx25821_risc_buffer(dev->pci, &buf->risc,
                                            dma->sglist,
                                            0, buf->bpl * (buf->vb.height >> 1),
                                            buf->bpl, 0, buf->vb.height >> 1);
                        break;
                case V4L2_FIELD_SEQ_BT:
                        cx25821_risc_buffer(dev->pci, &buf->risc,
                                            dma->sglist,
                                            buf->bpl * (buf->vb.height >> 1), 0,
                                            buf->bpl, 0, buf->vb.height >> 1);
                        break;
                default:
                        BUG();
                }
        }

        dprintk(2, "[%p/%d] buffer_prep - %dx%d %dbpp \"%s\" - dma=0x%08lx\n",
                buf, buf->vb.i, chan->width, chan->height, chan->fmt->depth,
                chan->fmt->name, (unsigned long)buf->risc.dma);

        buf->vb.state = VIDEOBUF_PREPARED;

        return 0;

fail:
        cx25821_free_buffer(q, buf);
        return rc;
}

static void cx25821_buffer_release(struct videobuf_queue *q,
                            struct videobuf_buffer *vb)
{
        struct cx25821_buffer *buf =
                container_of(vb, struct cx25821_buffer, vb);

        cx25821_free_buffer(q, buf);
}

static int cx25821_video_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct cx25821_channel *chan = video_drvdata(file);

        return videobuf_mmap_mapper(&chan->vidq, vma);
}


static void buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
{
        struct cx25821_buffer *buf =
                container_of(vb, struct cx25821_buffer, vb);
        struct cx25821_buffer *prev;
        struct cx25821_channel *chan = vq->priv_data;
        struct cx25821_dev *dev = chan->dev;
        struct cx25821_dmaqueue *q = &dev->channels[chan->id].dma_vidq;

        /* add jump to stopper */
        buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_IRQ1 | RISC_CNT_INC);
        buf->risc.jmp[1] = cpu_to_le32(q->stopper.dma);
        buf->risc.jmp[2] = cpu_to_le32(0);      /* bits 63-32 */

        dprintk(2, "jmp to stopper (0x%x)\n", buf->risc.jmp[1]);

        if (!list_empty(&q->queued)) {
                list_add_tail(&buf->vb.queue, &q->queued);
                buf->vb.state = VIDEOBUF_QUEUED;
                dprintk(2, "[%p/%d] buffer_queue - append to queued\n", buf,
                                buf->vb.i);

        } else if (list_empty(&q->active)) {
                list_add_tail(&buf->vb.queue, &q->active);
                cx25821_start_video_dma(dev, q, buf, chan->sram_channels);
                buf->vb.state = VIDEOBUF_ACTIVE;
                buf->count = q->count++;
                mod_timer(&q->timeout, jiffies + BUFFER_TIMEOUT);
                dprintk(2, "[%p/%d] buffer_queue - first active, buf cnt = %d, q->count = %d\n",
                                buf, buf->vb.i, buf->count, q->count);
        } else {
                prev = list_entry(q->active.prev, struct cx25821_buffer,
                                vb.queue);
                if (prev->vb.width == buf->vb.width
                   && prev->vb.height == buf->vb.height
                   && prev->fmt == buf->fmt) {
                        list_add_tail(&buf->vb.queue, &q->active);
                        buf->vb.state = VIDEOBUF_ACTIVE;
                        buf->count = q->count++;
                        prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);

                        /* 64 bit bits 63-32 */
                        prev->risc.jmp[2] = cpu_to_le32(0);
                        dprintk(2, "[%p/%d] buffer_queue - append to active, buf->count=%d\n",
                                        buf, buf->vb.i, buf->count);

                } else {
                        list_add_tail(&buf->vb.queue, &q->queued);
                        buf->vb.state = VIDEOBUF_QUEUED;
                        dprintk(2, "[%p/%d] buffer_queue - first queued\n", buf,
                                        buf->vb.i);
                }
        }

        if (list_empty(&q->active))
                dprintk(2, "active queue empty!\n");
}

static struct videobuf_queue_ops cx25821_video_qops = {
        .buf_setup = cx25821_buffer_setup,
        .buf_prepare = cx25821_buffer_prepare,
        .buf_queue = buffer_queue,
        .buf_release = cx25821_buffer_release,
};

static ssize_t video_read(struct file *file, char __user * data, size_t count,
                         loff_t *ppos)
{
        struct v4l2_fh *fh = file->private_data;
        struct cx25821_channel *chan = video_drvdata(file);
        struct cx25821_dev *dev = chan->dev;
        int err = 0;

        if (mutex_lock_interruptible(&dev->lock))
                return -ERESTARTSYS;
        if (chan->streaming_fh && chan->streaming_fh != fh) {
                err = -EBUSY;
                goto unlock;
        }
        chan->streaming_fh = fh;

        err = videobuf_read_one(&chan->vidq, data, count, ppos,
                                file->f_flags & O_NONBLOCK);
unlock:
        mutex_unlock(&dev->lock);
        return err;
}

static unsigned int video_poll(struct file *file,
                              struct poll_table_struct *wait)
{
        struct cx25821_channel *chan = video_drvdata(file);
        unsigned long req_events = poll_requested_events(wait);
        unsigned int res = v4l2_ctrl_poll(file, wait);

        if (req_events & (POLLIN | POLLRDNORM))
                res |= videobuf_poll_stream(file, &chan->vidq, wait);
        return res;

        /* This doesn't belong in poll(). This can be done
         * much better with vb2. We keep this code here as a
         * reminder.
        if ((res & POLLIN) && buf->vb.state == VIDEOBUF_DONE) {
                struct cx25821_dev *dev = chan->dev;

                if (dev && chan->use_cif_resolution) {
                        u8 cam_id = *((char *)buf->vb.baddr + 3);
                        memcpy((char *)buf->vb.baddr,
                                        (char *)buf->vb.baddr + (chan->width * 2),
                                        (chan->width * 2));
                        *((char *)buf->vb.baddr + 3) = cam_id;
                }
        }
         */
}

static int video_release(struct file *file)
{
        struct cx25821_channel *chan = video_drvdata(file);
        struct v4l2_fh *fh = file->private_data;
        struct cx25821_dev *dev = chan->dev;
        const struct sram_channel *sram_ch =
                dev->channels[0].sram_channels;

        mutex_lock(&dev->lock);
        /* stop the risc engine and fifo */
        cx_write(sram_ch->dma_ctl, 0); /* FIFO and RISC disable */

        /* stop video capture */
        if (chan->streaming_fh == fh) {
                videobuf_queue_cancel(&chan->vidq);
                chan->streaming_fh = NULL;
        }

        if (chan->vidq.read_buf) {
                cx25821_buffer_release(&chan->vidq, chan->vidq.read_buf);
                kfree(chan->vidq.read_buf);
        }

        videobuf_mmap_free(&chan->vidq);
        mutex_unlock(&dev->lock);

        return v4l2_fh_release(file);
}

/* VIDEO IOCTLS */

static int cx25821_vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
                            struct v4l2_fmtdesc *f)
{
        if (unlikely(f->index >= ARRAY_SIZE(formats)))
                return -EINVAL;

        strlcpy(f->description, formats[f->index].name, sizeof(f->description));
        f->pixelformat = formats[f->index].fourcc;

        return 0;
}

static int cx25821_vidioc_g_fmt_vid_cap(struct file *file, void *priv,
                                 struct v4l2_format *f)
{
        struct cx25821_channel *chan = video_drvdata(file);

        f->fmt.pix.width = chan->width;
        f->fmt.pix.height = chan->height;
        f->fmt.pix.field = chan->vidq.field;
        f->fmt.pix.pixelformat = chan->fmt->fourcc;
        f->fmt.pix.bytesperline = (chan->width * chan->fmt->depth) >> 3;
        f->fmt.pix.sizeimage = chan->height * f->fmt.pix.bytesperline;
        f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
        f->fmt.pix.priv = 0;

        return 0;
}

static int cx25821_vidioc_try_fmt_vid_cap(struct file *file, void *priv,
                                   struct v4l2_format *f)
{
        struct cx25821_channel *chan = video_drvdata(file);
        struct cx25821_dev *dev = chan->dev;
        const struct cx25821_fmt *fmt;
        enum v4l2_field field = f->fmt.pix.field;
        unsigned int maxh;
        unsigned w;

        fmt = cx25821_format_by_fourcc(f->fmt.pix.pixelformat);
        if (NULL == fmt)
                return -EINVAL;
        maxh = (dev->tvnorm & V4L2_STD_625_50) ? 576 : 480;

        w = f->fmt.pix.width;
        if (field != V4L2_FIELD_BOTTOM)
                field = V4L2_FIELD_TOP;
        if (w < 352) {
                w = 176;
                f->fmt.pix.height = maxh / 4;
        } else if (w < 720) {
                w = 352;
                f->fmt.pix.height = maxh / 2;
        } else {
                w = 720;
                f->fmt.pix.height = maxh;
                field = V4L2_FIELD_INTERLACED;
        }
        f->fmt.pix.field = field;
        f->fmt.pix.width = w;
        f->fmt.pix.bytesperline = (f->fmt.pix.width * fmt->depth) >> 3;
        f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
        f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
        f->fmt.pix.priv = 0;

        return 0;
}

static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        struct cx25821_channel *chan = video_drvdata(file);
        struct cx25821_dev *dev = chan->dev;
        int pix_format = PIXEL_FRMT_422;
        int err;

        err = cx25821_vidioc_try_fmt_vid_cap(file, priv, f);

        if (0 != err)
                return err;

        chan->fmt = cx25821_format_by_fourcc(f->fmt.pix.pixelformat);
        chan->vidq.field = f->fmt.pix.field;
        chan->width = f->fmt.pix.width;
        chan->height = f->fmt.pix.height;

        if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_Y41P)
                pix_format = PIXEL_FRMT_411;
        else
                pix_format = PIXEL_FRMT_422;

        cx25821_set_pixel_format(dev, SRAM_CH00, pix_format);

        /* check if cif resolution */
        if (chan->width == 320 || chan->width == 352)
                chan->use_cif_resolution = 1;
        else
                chan->use_cif_resolution = 0;

        chan->cif_width = chan->width;
        medusa_set_resolution(dev, chan->width, SRAM_CH00);
        return 0;
}

static int vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
{
        struct cx25821_channel *chan = video_drvdata(file);

        if (i != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;

        if (chan->streaming_fh && chan->streaming_fh != priv)
                return -EBUSY;
        chan->streaming_fh = priv;

        return videobuf_streamon(&chan->vidq);
}

static int vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
{
        struct cx25821_channel *chan = video_drvdata(file);

        if (i != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;

        if (chan->streaming_fh && chan->streaming_fh != priv)
                return -EBUSY;
        if (chan->streaming_fh == NULL)
                return 0;

        chan->streaming_fh = NULL;
        return videobuf_streamoff(&chan->vidq);
}

static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
        int ret_val = 0;
        struct cx25821_channel *chan = video_drvdata(file);

        ret_val = videobuf_dqbuf(&chan->vidq, p, file->f_flags & O_NONBLOCK);
        p->sequence = chan->dma_vidq.count;

        return ret_val;
}

static int vidioc_log_status(struct file *file, void *priv)
{
        struct cx25821_channel *chan = video_drvdata(file);
        struct cx25821_dev *dev = chan->dev;
        const struct sram_channel *sram_ch = chan->sram_channels;
        u32 tmp = 0;

        tmp = cx_read(sram_ch->dma_ctl);
        pr_info("Video input 0 is %s\n",
                (tmp & 0x11) ? "streaming" : "stopped");
        return 0;
}


static int cx25821_vidioc_querycap(struct file *file, void *priv,
                            struct v4l2_capability *cap)
{
        struct cx25821_channel *chan = video_drvdata(file);
        struct cx25821_dev *dev = chan->dev;
        const u32 cap_input = V4L2_CAP_VIDEO_CAPTURE |
                        V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
        const u32 cap_output = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_READWRITE;

        strcpy(cap->driver, "cx25821");
        strlcpy(cap->card, cx25821_boards[dev->board].name, sizeof(cap->card));
        sprintf(cap->bus_info, "PCIe:%s", pci_name(dev->pci));
        if (chan->id >= VID_CHANNEL_NUM)
                cap->device_caps = cap_output;
        else
                cap->device_caps = cap_input;
        cap->capabilities = cap_input | cap_output | V4L2_CAP_DEVICE_CAPS;
        return 0;
}

static int cx25821_vidioc_reqbufs(struct file *file, void *priv,
                           struct v4l2_requestbuffers *p)
{
        struct cx25821_channel *chan = video_drvdata(file);

        return videobuf_reqbufs(&chan->vidq, p);
}

static int cx25821_vidioc_querybuf(struct file *file, void *priv,
                            struct v4l2_buffer *p)
{
        struct cx25821_channel *chan = video_drvdata(file);

        return videobuf_querybuf(&chan->vidq, p);
}

static int cx25821_vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
        struct cx25821_channel *chan = video_drvdata(file);

        return videobuf_qbuf(&chan->vidq, p);
}

static int cx25821_vidioc_g_std(struct file *file, void *priv, v4l2_std_id *tvnorms)
{
        struct cx25821_channel *chan = video_drvdata(file);

        *tvnorms = chan->dev->tvnorm;
        return 0;
}

static int cx25821_vidioc_s_std(struct file *file, void *priv,
                                v4l2_std_id tvnorms)
{
        struct cx25821_channel *chan = video_drvdata(file);
        struct cx25821_dev *dev = chan->dev;

        if (dev->tvnorm == tvnorms)
                return 0;

        dev->tvnorm = tvnorms;
        chan->width = 720;
        chan->height = (dev->tvnorm & V4L2_STD_625_50) ? 576 : 480;

        medusa_set_videostandard(dev);

        return 0;
}

static int cx25821_vidioc_enum_input(struct file *file, void *priv,
                              struct v4l2_input *i)
{
        if (i->index)
                return -EINVAL;

        i->type = V4L2_INPUT_TYPE_CAMERA;
        i->std = CX25821_NORMS;
        strcpy(i->name, "Composite");
        return 0;
}

static int cx25821_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
{
        *i = 0;
        return 0;
}

static int cx25821_vidioc_s_input(struct file *file, void *priv, unsigned int i)
{
        return i ? -EINVAL : 0;
}

static int cx25821_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct cx25821_channel *chan =
                container_of(ctrl->handler, struct cx25821_channel, hdl);
        struct cx25821_dev *dev = chan->dev;

        switch (ctrl->id) {
        case V4L2_CID_BRIGHTNESS:
                medusa_set_brightness(dev, ctrl->val, chan->id);
                break;
        case V4L2_CID_HUE:
                medusa_set_hue(dev, ctrl->val, chan->id);
                break;
        case V4L2_CID_CONTRAST:
                medusa_set_contrast(dev, ctrl->val, chan->id);
                break;
        case V4L2_CID_SATURATION:
                medusa_set_saturation(dev, ctrl->val, chan->id);
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static int cx25821_vidioc_enum_output(struct file *file, void *priv,
                              struct v4l2_output *o)
{
        if (o->index)
                return -EINVAL;

        o->type = V4L2_INPUT_TYPE_CAMERA;
        o->std = CX25821_NORMS;
        strcpy(o->name, "Composite");
        return 0;
}

static int cx25821_vidioc_g_output(struct file *file, void *priv, unsigned int *o)
{
        *o = 0;
        return 0;
}

static int cx25821_vidioc_s_output(struct file *file, void *priv, unsigned int o)
{
        return o ? -EINVAL : 0;
}

static int cx25821_vidioc_try_fmt_vid_out(struct file *file, void *priv,
                                   struct v4l2_format *f)
{
        struct cx25821_channel *chan = video_drvdata(file);
        struct cx25821_dev *dev = chan->dev;
        const struct cx25821_fmt *fmt;

        fmt = cx25821_format_by_fourcc(f->fmt.pix.pixelformat);
        if (NULL == fmt)
                return -EINVAL;
        f->fmt.pix.width = 720;
        f->fmt.pix.height = (dev->tvnorm & V4L2_STD_625_50) ? 576 : 480;
        f->fmt.pix.field = V4L2_FIELD_INTERLACED;
        f->fmt.pix.bytesperline = (f->fmt.pix.width * fmt->depth) >> 3;
        f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
        f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
        f->fmt.pix.priv = 0;
        return 0;
}

static int vidioc_s_fmt_vid_out(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        struct cx25821_channel *chan = video_drvdata(file);
        int err;

        err = cx25821_vidioc_try_fmt_vid_out(file, priv, f);

        if (0 != err)
                return err;

        chan->fmt = cx25821_format_by_fourcc(f->fmt.pix.pixelformat);
        chan->vidq.field = f->fmt.pix.field;
        chan->width = f->fmt.pix.width;
        chan->height = f->fmt.pix.height;
        if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_Y41P)
                chan->pixel_formats = PIXEL_FRMT_411;
        else
                chan->pixel_formats = PIXEL_FRMT_422;
        return 0;
}

static ssize_t video_write(struct file *file, const char __user *data, size_t count,
                         loff_t *ppos)
{
        struct cx25821_channel *chan = video_drvdata(file);
        struct cx25821_dev *dev = chan->dev;
        struct v4l2_fh *fh = file->private_data;
        int err = 0;

        if (mutex_lock_interruptible(&dev->lock))
                return -ERESTARTSYS;
        if (chan->streaming_fh && chan->streaming_fh != fh) {
                err = -EBUSY;
                goto unlock;
        }
        if (!chan->streaming_fh) {
                err = cx25821_vidupstream_init(chan, chan->pixel_formats);
                if (err)
                        goto unlock;
                chan->streaming_fh = fh;
        }

        err = cx25821_write_frame(chan, data, count);
        count -= err;
        *ppos += err;

unlock:
        mutex_unlock(&dev->lock);
        return err;
}

static int video_out_release(struct file *file)
{
        struct cx25821_channel *chan = video_drvdata(file);
        struct cx25821_dev *dev = chan->dev;
        struct v4l2_fh *fh = file->private_data;

        mutex_lock(&dev->lock);
        if (chan->streaming_fh == fh) {
                cx25821_stop_upstream_video(chan);
                chan->streaming_fh = NULL;
        }
        mutex_unlock(&dev->lock);

        return v4l2_fh_release(file);
}

static const struct v4l2_ctrl_ops cx25821_ctrl_ops = {
        .s_ctrl = cx25821_s_ctrl,
};

static const struct v4l2_file_operations video_fops = {
        .owner = THIS_MODULE,
        .open = v4l2_fh_open,
        .release = video_release,
        .read = video_read,
        .poll = video_poll,
        .mmap = cx25821_video_mmap,
        .unlocked_ioctl = video_ioctl2,
};

static const struct v4l2_ioctl_ops video_ioctl_ops = {
        .vidioc_querycap = cx25821_vidioc_querycap,
        .vidioc_enum_fmt_vid_cap = cx25821_vidioc_enum_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap = cx25821_vidioc_g_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap = cx25821_vidioc_try_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap = vidioc_s_fmt_vid_cap,
        .vidioc_reqbufs = cx25821_vidioc_reqbufs,
        .vidioc_querybuf = cx25821_vidioc_querybuf,
        .vidioc_qbuf = cx25821_vidioc_qbuf,
        .vidioc_dqbuf = vidioc_dqbuf,
        .vidioc_g_std = cx25821_vidioc_g_std,
        .vidioc_s_std = cx25821_vidioc_s_std,
        .vidioc_enum_input = cx25821_vidioc_enum_input,
        .vidioc_g_input = cx25821_vidioc_g_input,
        .vidioc_s_input = cx25821_vidioc_s_input,
        .vidioc_streamon = vidioc_streamon,
        .vidioc_streamoff = vidioc_streamoff,
        .vidioc_log_status = vidioc_log_status,
        .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static const struct video_device cx25821_video_device = {
        .name = "cx25821-video",
        .fops = &video_fops,
        .release = video_device_release_empty,
        .minor = -1,
        .ioctl_ops = &video_ioctl_ops,
        .tvnorms = CX25821_NORMS,
};

static const struct v4l2_file_operations video_out_fops = {
        .owner = THIS_MODULE,
        .open = v4l2_fh_open,
        .write = video_write,
        .release = video_out_release,
        .unlocked_ioctl = video_ioctl2,
};

static const struct v4l2_ioctl_ops video_out_ioctl_ops = {
        .vidioc_querycap = cx25821_vidioc_querycap,
        .vidioc_enum_fmt_vid_out = cx25821_vidioc_enum_fmt_vid_cap,
        .vidioc_g_fmt_vid_out = cx25821_vidioc_g_fmt_vid_cap,
        .vidioc_try_fmt_vid_out = cx25821_vidioc_try_fmt_vid_out,
        .vidioc_s_fmt_vid_out = vidioc_s_fmt_vid_out,

        .vidioc_g_std = cx25821_vidioc_g_std,
        .vidioc_s_std = cx25821_vidioc_s_std,
        .vidioc_enum_output = cx25821_vidioc_enum_output,
        .vidioc_g_output = cx25821_vidioc_g_output,
        .vidioc_s_output = cx25821_vidioc_s_output,
        .vidioc_log_status = vidioc_log_status,
};

static const struct video_device cx25821_video_out_device = {
        .name = "cx25821-video",
        .fops = &video_out_fops,
        .release = video_device_release_empty,
        .minor = -1,
        .ioctl_ops = &video_out_ioctl_ops,
        .tvnorms = CX25821_NORMS,
};

void cx25821_video_unregister(struct cx25821_dev *dev, int chan_num)
{
        cx_clear(PCI_INT_MSK, 1);

        if (video_is_registered(&dev->channels[chan_num].vdev)) {
                video_unregister_device(&dev->channels[chan_num].vdev);
                v4l2_ctrl_handler_free(&dev->channels[chan_num].hdl);

                btcx_riscmem_free(dev->pci,
                                &dev->channels[chan_num].dma_vidq.stopper);
        }
}

int cx25821_video_register(struct cx25821_dev *dev)
{
        int err;
        int i;

        /* initial device configuration */
        dev->tvnorm = V4L2_STD_NTSC_M;

        spin_lock_init(&dev->slock);

        for (i = 0; i < MAX_VID_CHANNEL_NUM - 1; ++i) {
                struct cx25821_channel *chan = &dev->channels[i];
                struct video_device *vdev = &chan->vdev;
                struct v4l2_ctrl_handler *hdl = &chan->hdl;
                bool is_output = i > SRAM_CH08;

                if (i == SRAM_CH08) /* audio channel */
                        continue;

                if (!is_output) {
                        v4l2_ctrl_handler_init(hdl, 4);
                        v4l2_ctrl_new_std(hdl, &cx25821_ctrl_ops,
                                        V4L2_CID_BRIGHTNESS, 0, 10000, 1, 6200);
                        v4l2_ctrl_new_std(hdl, &cx25821_ctrl_ops,
                                        V4L2_CID_CONTRAST, 0, 10000, 1, 5000);
                        v4l2_ctrl_new_std(hdl, &cx25821_ctrl_ops,
                                        V4L2_CID_SATURATION, 0, 10000, 1, 5000);
                        v4l2_ctrl_new_std(hdl, &cx25821_ctrl_ops,
                                        V4L2_CID_HUE, 0, 10000, 1, 5000);
                        if (hdl->error) {
                                err = hdl->error;
                                goto fail_unreg;
                        }
                        err = v4l2_ctrl_handler_setup(hdl);
                        if (err)
                                goto fail_unreg;
                } else {
                        chan->out = &dev->vid_out_data[i - SRAM_CH09];
                        chan->out->chan = chan;
                }

                cx25821_risc_stopper(dev->pci, &chan->dma_vidq.stopper,
                        chan->sram_channels->dma_ctl, 0x11, 0);

                chan->sram_channels = &cx25821_sram_channels[i];
                chan->width = 720;
                if (dev->tvnorm & V4L2_STD_625_50)
                        chan->height = 576;
                else
                        chan->height = 480;

                if (chan->pixel_formats == PIXEL_FRMT_411)
                        chan->fmt = cx25821_format_by_fourcc(V4L2_PIX_FMT_Y41P);
                else
                        chan->fmt = cx25821_format_by_fourcc(V4L2_PIX_FMT_YUYV);

                cx_write(chan->sram_channels->int_stat, 0xffffffff);

                INIT_LIST_HEAD(&chan->dma_vidq.active);
                INIT_LIST_HEAD(&chan->dma_vidq.queued);

                chan->timeout_data.dev = dev;
                chan->timeout_data.channel = &cx25821_sram_channels[i];
                chan->dma_vidq.timeout.function = cx25821_vid_timeout;
                chan->dma_vidq.timeout.data = (unsigned long)&chan->timeout_data;
                init_timer(&chan->dma_vidq.timeout);

                if (!is_output)
                        videobuf_queue_sg_init(&chan->vidq, &cx25821_video_qops, &dev->pci->dev,
                                &dev->slock, V4L2_BUF_TYPE_VIDEO_CAPTURE,
                                V4L2_FIELD_INTERLACED, sizeof(struct cx25821_buffer),
                                chan, &dev->lock);

                /* register v4l devices */
                *vdev = is_output ? cx25821_video_out_device : cx25821_video_device;
                vdev->v4l2_dev = &dev->v4l2_dev;
                if (!is_output)
                        vdev->ctrl_handler = hdl;
                else
                        vdev->vfl_dir = VFL_DIR_TX;
                vdev->lock = &dev->lock;
                set_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags);
                snprintf(vdev->name, sizeof(vdev->name), "%s #%d", dev->name, i);
                video_set_drvdata(vdev, chan);

                err = video_register_device(vdev, VFL_TYPE_GRABBER,
                                            video_nr[dev->nr]);

                if (err < 0)
                        goto fail_unreg;
        }

        /* set PCI interrupt */
        cx_set(PCI_INT_MSK, 0xff);

        return 0;

fail_unreg:
        while (i >= 0)
                cx25821_video_unregister(dev, i--);
        return err;
}