Merge tag 'trace-printf-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace...

[drm/drm-misc.git] / drivers / media / pci / cx18 / cx18-streams.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  cx18 init/start/stop/exit stream functions
 *
 *  Derived from ivtv-streams.c
 *
 *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
 *  Copyright (C) 2008  Andy Walls <awalls@md.metrocast.net>
 */

#include "cx18-driver.h"
#include "cx18-io.h"
#include "cx18-fileops.h"
#include "cx18-mailbox.h"
#include "cx18-i2c.h"
#include "cx18-queue.h"
#include "cx18-ioctl.h"
#include "cx18-streams.h"
#include "cx18-cards.h"
#include "cx18-scb.h"
#include "cx18-dvb.h"

#define CX18_DSP0_INTERRUPT_MASK        0xd0004C

static const struct v4l2_file_operations cx18_v4l2_enc_fops = {
        .owner = THIS_MODULE,
        .read = cx18_v4l2_read,
        .open = cx18_v4l2_open,
        .unlocked_ioctl = video_ioctl2,
        .release = cx18_v4l2_close,
        .poll = cx18_v4l2_enc_poll,
};

static const struct v4l2_file_operations cx18_v4l2_enc_yuv_fops = {
        .owner = THIS_MODULE,
        .open = cx18_v4l2_open,
        .unlocked_ioctl = video_ioctl2,
        .release = cx18_v4l2_close,
        .poll = vb2_fop_poll,
        .read = vb2_fop_read,
        .mmap = vb2_fop_mmap,
};

/* offset from 0 to register ts v4l2 minors on */
#define CX18_V4L2_ENC_TS_OFFSET   16
/* offset from 0 to register pcm v4l2 minors on */
#define CX18_V4L2_ENC_PCM_OFFSET  24
/* offset from 0 to register yuv v4l2 minors on */
#define CX18_V4L2_ENC_YUV_OFFSET  32

static struct {
        const char *name;
        int vfl_type;
        int num_offset;
        int dma;
        u32 caps;
} cx18_stream_info[] = {
        {       /* CX18_ENC_STREAM_TYPE_MPG */
                "encoder MPEG",
                VFL_TYPE_VIDEO, 0,
                DMA_FROM_DEVICE,
                V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
                V4L2_CAP_AUDIO | V4L2_CAP_TUNER
        },
        {       /* CX18_ENC_STREAM_TYPE_TS */
                "TS",
                VFL_TYPE_VIDEO, -1,
                DMA_FROM_DEVICE,
        },
        {       /* CX18_ENC_STREAM_TYPE_YUV */
                "encoder YUV",
                VFL_TYPE_VIDEO, CX18_V4L2_ENC_YUV_OFFSET,
                DMA_FROM_DEVICE,
                V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
                V4L2_CAP_STREAMING | V4L2_CAP_AUDIO | V4L2_CAP_TUNER
        },
        {       /* CX18_ENC_STREAM_TYPE_VBI */
                "encoder VBI",
                VFL_TYPE_VBI, 0,
                DMA_FROM_DEVICE,
                V4L2_CAP_VBI_CAPTURE | V4L2_CAP_SLICED_VBI_CAPTURE |
                V4L2_CAP_READWRITE | V4L2_CAP_AUDIO | V4L2_CAP_TUNER
        },
        {       /* CX18_ENC_STREAM_TYPE_PCM */
                "encoder PCM audio",
                VFL_TYPE_VIDEO, CX18_V4L2_ENC_PCM_OFFSET,
                DMA_FROM_DEVICE,
                V4L2_CAP_TUNER | V4L2_CAP_AUDIO | V4L2_CAP_READWRITE,
        },
        {       /* CX18_ENC_STREAM_TYPE_IDX */
                "encoder IDX",
                VFL_TYPE_VIDEO, -1,
                DMA_FROM_DEVICE,
        },
        {       /* CX18_ENC_STREAM_TYPE_RAD */
                "encoder radio",
                VFL_TYPE_RADIO, 0,
                DMA_NONE,
                V4L2_CAP_RADIO | V4L2_CAP_TUNER
        },
};

static int cx18_queue_setup(struct vb2_queue *vq,
                            unsigned int *nbuffers, unsigned int *nplanes,
                            unsigned int sizes[], struct device *alloc_devs[])
{
        unsigned int q_num_bufs = vb2_get_num_buffers(vq);
        struct cx18_stream *s = vb2_get_drv_priv(vq);
        struct cx18 *cx = s->cx;
        unsigned int szimage;

        /*
         * HM12 YUV size is (Y=(h*720) + UV=(h*(720/2)))
         * UYUV YUV size is (Y=(h*720) + UV=(h*(720)))
         */
        if (s->pixelformat == V4L2_PIX_FMT_NV12_16L16)
                szimage = cx->cxhdl.height * 720 * 3 / 2;
        else
                szimage = cx->cxhdl.height * 720 * 2;

        /*
         * Let's request at least three buffers: two for the
         * DMA engine and one for userspace.
         */
        if (q_num_bufs + *nbuffers < 3)
                *nbuffers = 3 - q_num_bufs;

        if (*nplanes) {
                if (*nplanes != 1 || sizes[0] < szimage)
                        return -EINVAL;
                return 0;
        }

        sizes[0] = szimage;
        *nplanes = 1;
        return 0;
}

static void cx18_buf_queue(struct vb2_buffer *vb)
{
        struct cx18_stream *s = vb2_get_drv_priv(vb->vb2_queue);
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct cx18_vb2_buffer *buf =
                container_of(vbuf, struct cx18_vb2_buffer, vb);
        unsigned long flags;

        spin_lock_irqsave(&s->vb_lock, flags);
        list_add_tail(&buf->list, &s->vb_capture);
        spin_unlock_irqrestore(&s->vb_lock, flags);
}

static int cx18_buf_prepare(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct cx18_stream *s = vb2_get_drv_priv(vb->vb2_queue);
        struct cx18 *cx = s->cx;
        unsigned int size;

        /*
         * HM12 YUV size is (Y=(h*720) + UV=(h*(720/2)))
         * UYUV YUV size is (Y=(h*720) + UV=(h*(720)))
         */
        if (s->pixelformat == V4L2_PIX_FMT_NV12_16L16)
                size = cx->cxhdl.height * 720 * 3 / 2;
        else
                size = cx->cxhdl.height * 720 * 2;

        if (vb2_plane_size(vb, 0) < size)
                return -EINVAL;
        vb2_set_plane_payload(vb, 0, size);
        vbuf->field = V4L2_FIELD_INTERLACED;
        return 0;
}

void cx18_clear_queue(struct cx18_stream *s, enum vb2_buffer_state state)
{
        while (!list_empty(&s->vb_capture)) {
                struct cx18_vb2_buffer *buf;

                buf = list_first_entry(&s->vb_capture,
                                       struct cx18_vb2_buffer, list);
                list_del(&buf->list);
                vb2_buffer_done(&buf->vb.vb2_buf, state);
        }
}

static int cx18_start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct v4l2_fh *owner = vq->owner;
        struct cx18_stream *s = vb2_get_drv_priv(vq);
        unsigned long flags;
        int rc;

        if (WARN_ON(!owner)) {
                rc = -EIO;
                goto clear_queue;
        }

        s->sequence = 0;
        rc = cx18_start_capture(fh2id(owner));
        if (!rc) {
                /* Establish a buffer timeout */
                mod_timer(&s->vb_timeout, msecs_to_jiffies(2000) + jiffies);
                return 0;
        }

clear_queue:
        spin_lock_irqsave(&s->vb_lock, flags);
        cx18_clear_queue(s, VB2_BUF_STATE_QUEUED);
        spin_unlock_irqrestore(&s->vb_lock, flags);
        return rc;
}

static void cx18_stop_streaming(struct vb2_queue *vq)
{
        struct cx18_stream *s = vb2_get_drv_priv(vq);
        unsigned long flags;

        cx18_stop_capture(s, 0);
        timer_delete_sync(&s->vb_timeout);
        spin_lock_irqsave(&s->vb_lock, flags);
        cx18_clear_queue(s, VB2_BUF_STATE_ERROR);
        spin_unlock_irqrestore(&s->vb_lock, flags);
}

static const struct vb2_ops cx18_vb2_qops = {
        .queue_setup            = cx18_queue_setup,
        .buf_queue              = cx18_buf_queue,
        .buf_prepare            = cx18_buf_prepare,
        .start_streaming        = cx18_start_streaming,
        .stop_streaming         = cx18_stop_streaming,
};

static int cx18_stream_init(struct cx18 *cx, int type)
{
        struct cx18_stream *s = &cx->streams[type];
        int err = 0;

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

        /* initialize cx18_stream fields */
        s->dvb = NULL;
        s->cx = cx;
        s->type = type;
        s->name = cx18_stream_info[type].name;
        s->handle = CX18_INVALID_TASK_HANDLE;

        s->dma = cx18_stream_info[type].dma;
        s->v4l2_dev_caps = cx18_stream_info[type].caps;
        s->buffers = cx->stream_buffers[type];
        s->buf_size = cx->stream_buf_size[type];
        INIT_LIST_HEAD(&s->buf_pool);
        s->bufs_per_mdl = 1;
        s->mdl_size = s->buf_size * s->bufs_per_mdl;

        init_waitqueue_head(&s->waitq);
        s->id = -1;
        spin_lock_init(&s->q_free.lock);
        cx18_queue_init(&s->q_free);
        spin_lock_init(&s->q_busy.lock);
        cx18_queue_init(&s->q_busy);
        spin_lock_init(&s->q_full.lock);
        cx18_queue_init(&s->q_full);
        spin_lock_init(&s->q_idle.lock);
        cx18_queue_init(&s->q_idle);

        INIT_WORK(&s->out_work_order, cx18_out_work_handler);

        INIT_LIST_HEAD(&s->vb_capture);
        timer_setup(&s->vb_timeout, cx18_vb_timeout, 0);
        spin_lock_init(&s->vb_lock);

        if (type == CX18_ENC_STREAM_TYPE_YUV) {
                s->vb_type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

                /* Assume the previous pixel default */
                s->pixelformat = V4L2_PIX_FMT_NV12_16L16;
                s->vb_bytes_per_frame = cx->cxhdl.height * 720 * 3 / 2;
                s->vb_bytes_per_line = 720;

                s->vidq.io_modes = VB2_READ | VB2_MMAP | VB2_DMABUF;
                s->vidq.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                s->vidq.drv_priv = s;
                s->vidq.buf_struct_size = sizeof(struct cx18_vb2_buffer);
                s->vidq.ops = &cx18_vb2_qops;
                s->vidq.mem_ops = &vb2_vmalloc_memops;
                s->vidq.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
                s->vidq.min_queued_buffers = 2;
                s->vidq.gfp_flags = GFP_DMA32;
                s->vidq.dev = &cx->pci_dev->dev;
                s->vidq.lock = &cx->serialize_lock;

                err = vb2_queue_init(&s->vidq);
                if (err)
                        v4l2_err(&cx->v4l2_dev, "cannot init vb2 queue\n");
                s->video_dev.queue = &s->vidq;
        }
        return err;
}

static int cx18_prep_dev(struct cx18 *cx, int type)
{
        struct cx18_stream *s = &cx->streams[type];
        u32 cap = cx->v4l2_cap;
        int num_offset = cx18_stream_info[type].num_offset;
        int num = cx->instance + cx18_first_minor + num_offset;
        int err;

        /*
         * These five fields are always initialized.
         * For analog capture related streams, if video_dev.v4l2_dev == NULL then the
         * stream is not in use.
         * For the TS stream, if dvb == NULL then the stream is not in use.
         * In those cases no other fields but these four can be used.
         */
        s->video_dev.v4l2_dev = NULL;
        s->dvb = NULL;
        s->cx = cx;
        s->type = type;
        s->name = cx18_stream_info[type].name;

        /* Check whether the radio is supported */
        if (type == CX18_ENC_STREAM_TYPE_RAD && !(cap & V4L2_CAP_RADIO))
                return 0;

        /* Check whether VBI is supported */
        if (type == CX18_ENC_STREAM_TYPE_VBI &&
            !(cap & (V4L2_CAP_VBI_CAPTURE | V4L2_CAP_SLICED_VBI_CAPTURE)))
                return 0;

        /* User explicitly selected 0 buffers for these streams, so don't
           create them. */
        if (cx18_stream_info[type].dma != DMA_NONE &&
            cx->stream_buffers[type] == 0) {
                CX18_INFO("Disabled %s device\n", cx18_stream_info[type].name);
                return 0;
        }

        err = cx18_stream_init(cx, type);
        if (err)
                return err;

        /* Allocate the cx18_dvb struct only for the TS on cards with DTV */
        if (type == CX18_ENC_STREAM_TYPE_TS) {
                if (cx->card->hw_all & CX18_HW_DVB) {
                        s->dvb = kzalloc(sizeof(struct cx18_dvb), GFP_KERNEL);
                        if (s->dvb == NULL) {
                                CX18_ERR("Couldn't allocate cx18_dvb structure for %s\n",
                                         s->name);
                                return -ENOMEM;
                        }
                } else {
                        /* Don't need buffers for the TS, if there is no DVB */
                        s->buffers = 0;
                }
        }

        if (num_offset == -1)
                return 0;

        /* initialize the v4l2 video device structure */
        snprintf(s->video_dev.name, sizeof(s->video_dev.name), "%s %s",
                 cx->v4l2_dev.name, s->name);

        s->video_dev.num = num;
        s->video_dev.v4l2_dev = &cx->v4l2_dev;
        if (type == CX18_ENC_STREAM_TYPE_YUV)
                s->video_dev.fops = &cx18_v4l2_enc_yuv_fops;
        else
                s->video_dev.fops = &cx18_v4l2_enc_fops;
        s->video_dev.release = video_device_release_empty;
        if (cx->card->video_inputs->video_type == CX18_CARD_INPUT_VID_TUNER)
                s->video_dev.tvnorms = cx->tuner_std;
        else
                s->video_dev.tvnorms = V4L2_STD_ALL;
        s->video_dev.lock = &cx->serialize_lock;
        cx18_set_funcs(&s->video_dev);
        return 0;
}

/* Initialize v4l2 variables and register v4l2 devices */
int cx18_streams_setup(struct cx18 *cx)
{
        int type, ret;

        /* Setup V4L2 Devices */
        for (type = 0; type < CX18_MAX_STREAMS; type++) {
                /* Prepare device */
                ret = cx18_prep_dev(cx, type);
                if (ret < 0)
                        break;

                /* Allocate Stream */
                ret = cx18_stream_alloc(&cx->streams[type]);
                if (ret < 0)
                        break;
        }
        if (type == CX18_MAX_STREAMS)
                return 0;

        /* One or more streams could not be initialized. Clean 'em all up. */
        cx18_streams_cleanup(cx, 0);
        return ret;
}

static int cx18_reg_dev(struct cx18 *cx, int type)
{
        struct cx18_stream *s = &cx->streams[type];
        int vfl_type = cx18_stream_info[type].vfl_type;
        const char *name;
        int num, ret;

        if (type == CX18_ENC_STREAM_TYPE_TS && s->dvb != NULL) {
                ret = cx18_dvb_register(s);
                if (ret < 0) {
                        CX18_ERR("DVB failed to register\n");
                        return ret;
                }
        }

        if (s->video_dev.v4l2_dev == NULL)
                return 0;

        num = s->video_dev.num;
        s->video_dev.device_caps = s->v4l2_dev_caps;    /* device capabilities */
        /* card number + user defined offset + device offset */
        if (type != CX18_ENC_STREAM_TYPE_MPG) {
                struct cx18_stream *s_mpg = &cx->streams[CX18_ENC_STREAM_TYPE_MPG];

                if (s_mpg->video_dev.v4l2_dev)
                        num = s_mpg->video_dev.num
                            + cx18_stream_info[type].num_offset;
        }
        video_set_drvdata(&s->video_dev, s);

        /* Register device. First try the desired minor, then any free one. */
        ret = video_register_device_no_warn(&s->video_dev, vfl_type, num);
        if (ret < 0) {
                CX18_ERR("Couldn't register v4l2 device for %s (device node number %d)\n",
                        s->name, num);
                s->video_dev.v4l2_dev = NULL;
                return ret;
        }

        name = video_device_node_name(&s->video_dev);

        switch (vfl_type) {
        case VFL_TYPE_VIDEO:
                CX18_INFO("Registered device %s for %s (%d x %d.%02d kB)\n",
                          name, s->name, cx->stream_buffers[type],
                          cx->stream_buf_size[type] / 1024,
                          (cx->stream_buf_size[type] * 100 / 1024) % 100);
                break;

        case VFL_TYPE_RADIO:
                CX18_INFO("Registered device %s for %s\n", name, s->name);
                break;

        case VFL_TYPE_VBI:
                if (cx->stream_buffers[type])
                        CX18_INFO("Registered device %s for %s (%d x %d bytes)\n",
                                  name, s->name, cx->stream_buffers[type],
                                  cx->stream_buf_size[type]);
                else
                        CX18_INFO("Registered device %s for %s\n",
                                name, s->name);
                break;
        }

        return 0;
}

/* Register v4l2 devices */
int cx18_streams_register(struct cx18 *cx)
{
        int type;
        int err;
        int ret = 0;

        /* Register V4L2 devices */
        for (type = 0; type < CX18_MAX_STREAMS; type++) {
                err = cx18_reg_dev(cx, type);
                if (err && ret == 0)
                        ret = err;
        }

        if (ret == 0)
                return 0;

        /* One or more streams could not be initialized. Clean 'em all up. */
        cx18_streams_cleanup(cx, 1);
        return ret;
}

/* Unregister v4l2 devices */
void cx18_streams_cleanup(struct cx18 *cx, int unregister)
{
        struct video_device *vdev;
        int type;

        /* Teardown all streams */
        for (type = 0; type < CX18_MAX_STREAMS; type++) {

                /* The TS has a cx18_dvb structure, not a video_device */
                if (type == CX18_ENC_STREAM_TYPE_TS) {
                        if (cx->streams[type].dvb != NULL) {
                                if (unregister)
                                        cx18_dvb_unregister(&cx->streams[type]);
                                kfree(cx->streams[type].dvb);
                                cx->streams[type].dvb = NULL;
                                cx18_stream_free(&cx->streams[type]);
                        }
                        continue;
                }

                /* No struct video_device, but can have buffers allocated */
                if (type == CX18_ENC_STREAM_TYPE_IDX) {
                        /* If the module params didn't inhibit IDX ... */
                        if (cx->stream_buffers[type] != 0) {
                                cx->stream_buffers[type] = 0;
                                /*
                                 * Before calling cx18_stream_free(),
                                 * check if the IDX stream was actually set up.
                                 * Needed, since the cx18_probe() error path
                                 * exits through here as well as normal clean up
                                 */
                                if (cx->streams[type].buffers != 0)
                                        cx18_stream_free(&cx->streams[type]);
                        }
                        continue;
                }

                /* If struct video_device exists, can have buffers allocated */
                vdev = &cx->streams[type].video_dev;

                if (vdev->v4l2_dev == NULL)
                        continue;

                cx18_stream_free(&cx->streams[type]);

                if (type == CX18_ENC_STREAM_TYPE_YUV)
                        vb2_video_unregister_device(vdev);
                else
                        video_unregister_device(vdev);
        }
}

static void cx18_vbi_setup(struct cx18_stream *s)
{
        struct cx18 *cx = s->cx;
        int raw = cx18_raw_vbi(cx);
        u32 data[CX2341X_MBOX_MAX_DATA];
        int lines;

        if (cx->is_60hz) {
                cx->vbi.count = 12;
                cx->vbi.start[0] = 10;
                cx->vbi.start[1] = 273;
        } else {        /* PAL/SECAM */
                cx->vbi.count = 18;
                cx->vbi.start[0] = 6;
                cx->vbi.start[1] = 318;
        }

        /* setup VBI registers */
        if (raw)
                v4l2_subdev_call(cx->sd_av, vbi, s_raw_fmt, &cx->vbi.in.fmt.vbi);
        else
                v4l2_subdev_call(cx->sd_av, vbi, s_sliced_fmt, &cx->vbi.in.fmt.sliced);

        /*
         * Send the CX18_CPU_SET_RAW_VBI_PARAM API command to setup Encoder Raw
         * VBI when the first analog capture channel starts, as once it starts
         * (e.g. MPEG), we can't effect any change in the Encoder Raw VBI setup
         * (i.e. for the VBI capture channels).  We also send it for each
         * analog capture channel anyway just to make sure we get the proper
         * behavior
         */
        if (raw) {
                lines = cx->vbi.count * 2;
        } else {
                /*
                 * For 525/60 systems, according to the VIP 2 & BT.656 std:
                 * The EAV RP code's Field bit toggles on line 4, a few lines
                 * after the Vertcal Blank bit has already toggled.
                 * Tell the encoder to capture 21-4+1=18 lines per field,
                 * since we want lines 10 through 21.
                 *
                 * For 625/50 systems, according to the VIP 2 & BT.656 std:
                 * The EAV RP code's Field bit toggles on line 1, a few lines
                 * after the Vertcal Blank bit has already toggled.
                 * (We've actually set the digitizer so that the Field bit
                 * toggles on line 2.) Tell the encoder to capture 23-2+1=22
                 * lines per field, since we want lines 6 through 23.
                 */
                lines = cx->is_60hz ? (21 - 4 + 1) * 2 : (23 - 2 + 1) * 2;
        }

        data[0] = s->handle;
        /* Lines per field */
        data[1] = (lines / 2) | ((lines / 2) << 16);
        /* bytes per line */
        data[2] = (raw ? VBI_ACTIVE_SAMPLES
                       : (cx->is_60hz ? VBI_HBLANK_SAMPLES_60HZ
                                      : VBI_HBLANK_SAMPLES_50HZ));
        /* Every X number of frames a VBI interrupt arrives
           (frames as in 25 or 30 fps) */
        data[3] = 1;
        /*
         * Set the SAV/EAV RP codes to look for as start/stop points
         * when in VIP-1.1 mode
         */
        if (raw) {
                /*
                 * Start codes for beginning of "active" line in vertical blank
                 * 0x20 (               VerticalBlank                )
                 * 0x60 (     EvenField VerticalBlank                )
                 */
                data[4] = 0x20602060;
                /*
                 * End codes for end of "active" raw lines and regular lines
                 * 0x30 (               VerticalBlank HorizontalBlank)
                 * 0x70 (     EvenField VerticalBlank HorizontalBlank)
                 * 0x90 (Task                         HorizontalBlank)
                 * 0xd0 (Task EvenField               HorizontalBlank)
                 */
                data[5] = 0x307090d0;
        } else {
                /*
                 * End codes for active video, we want data in the hblank region
                 * 0xb0 (Task         0 VerticalBlank HorizontalBlank)
                 * 0xf0 (Task EvenField VerticalBlank HorizontalBlank)
                 *
                 * Since the V bit is only allowed to toggle in the EAV RP code,
                 * just before the first active region line, these two
                 * are problematic:
                 * 0x90 (Task                         HorizontalBlank)
                 * 0xd0 (Task EvenField               HorizontalBlank)
                 *
                 * We have set the digitzer such that we don't have to worry
                 * about these problem codes.
                 */
                data[4] = 0xB0F0B0F0;
                /*
                 * Start codes for beginning of active line in vertical blank
                 * 0xa0 (Task           VerticalBlank                )
                 * 0xe0 (Task EvenField VerticalBlank                )
                 */
                data[5] = 0xA0E0A0E0;
        }

        CX18_DEBUG_INFO("Setup VBI h: %d lines %x bpl %d fr %d %x %x\n",
                        data[0], data[1], data[2], data[3], data[4], data[5]);

        cx18_api(cx, CX18_CPU_SET_RAW_VBI_PARAM, 6, data);
}

void cx18_stream_rotate_idx_mdls(struct cx18 *cx)
{
        struct cx18_stream *s = &cx->streams[CX18_ENC_STREAM_TYPE_IDX];
        struct cx18_mdl *mdl;

        if (!cx18_stream_enabled(s))
                return;

        /* Return if the firmware is not running low on MDLs */
        if ((atomic_read(&s->q_free.depth) + atomic_read(&s->q_busy.depth)) >=
                                            CX18_ENC_STREAM_TYPE_IDX_FW_MDL_MIN)
                return;

        /* Return if there are no MDLs to rotate back to the firmware */
        if (atomic_read(&s->q_full.depth) < 2)
                return;

        /*
         * Take the oldest IDX MDL still holding data, and discard its index
         * entries by scheduling the MDL to go back to the firmware
         */
        mdl = cx18_dequeue(s, &s->q_full);
        if (mdl != NULL)
                cx18_enqueue(s, mdl, &s->q_free);
}

static
struct cx18_queue *_cx18_stream_put_mdl_fw(struct cx18_stream *s,
                                           struct cx18_mdl *mdl)
{
        struct cx18 *cx = s->cx;
        struct cx18_queue *q;

        /* Don't give it to the firmware, if we're not running a capture */
        if (s->handle == CX18_INVALID_TASK_HANDLE ||
            test_bit(CX18_F_S_STOPPING, &s->s_flags) ||
            !test_bit(CX18_F_S_STREAMING, &s->s_flags))
                return cx18_enqueue(s, mdl, &s->q_free);

        q = cx18_enqueue(s, mdl, &s->q_busy);
        if (q != &s->q_busy)
                return q; /* The firmware has the max MDLs it can handle */

        cx18_mdl_sync_for_device(s, mdl);
        cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5, s->handle,
                  (void __iomem *) &cx->scb->cpu_mdl[mdl->id] - cx->enc_mem,
                  s->bufs_per_mdl, mdl->id, s->mdl_size);
        return q;
}

static
void _cx18_stream_load_fw_queue(struct cx18_stream *s)
{
        struct cx18_queue *q;
        struct cx18_mdl *mdl;

        if (atomic_read(&s->q_free.depth) == 0 ||
            atomic_read(&s->q_busy.depth) >= CX18_MAX_FW_MDLS_PER_STREAM)
                return;

        /* Move from q_free to q_busy notifying the firmware, until the limit */
        do {
                mdl = cx18_dequeue(s, &s->q_free);
                if (mdl == NULL)
                        break;
                q = _cx18_stream_put_mdl_fw(s, mdl);
        } while (atomic_read(&s->q_busy.depth) < CX18_MAX_FW_MDLS_PER_STREAM
                 && q == &s->q_busy);
}

void cx18_out_work_handler(struct work_struct *work)
{
        struct cx18_stream *s =
                         container_of(work, struct cx18_stream, out_work_order);

        _cx18_stream_load_fw_queue(s);
}

static void cx18_stream_configure_mdls(struct cx18_stream *s)
{
        cx18_unload_queues(s);

        switch (s->type) {
        case CX18_ENC_STREAM_TYPE_YUV:
                /*
                 * Height should be a multiple of 32 lines.
                 * Set the MDL size to the exact size needed for one frame.
                 * Use enough buffers per MDL to cover the MDL size
                 */
                if (s->pixelformat == V4L2_PIX_FMT_NV12_16L16)
                        s->mdl_size = 720 * s->cx->cxhdl.height * 3 / 2;
                else
                        s->mdl_size = 720 * s->cx->cxhdl.height * 2;
                s->bufs_per_mdl = s->mdl_size / s->buf_size;
                if (s->mdl_size % s->buf_size)
                        s->bufs_per_mdl++;
                break;
        case CX18_ENC_STREAM_TYPE_VBI:
                s->bufs_per_mdl = 1;
                if  (cx18_raw_vbi(s->cx)) {
                        s->mdl_size = (s->cx->is_60hz ? 12 : 18)
                                                       * 2 * VBI_ACTIVE_SAMPLES;
                } else {
                        /*
                         * See comment in cx18_vbi_setup() below about the
                         * extra lines we capture in sliced VBI mode due to
                         * the lines on which EAV RP codes toggle.
                        */
                        s->mdl_size = s->cx->is_60hz
                                   ? (21 - 4 + 1) * 2 * VBI_HBLANK_SAMPLES_60HZ
                                   : (23 - 2 + 1) * 2 * VBI_HBLANK_SAMPLES_50HZ;
                }
                break;
        default:
                s->bufs_per_mdl = 1;
                s->mdl_size = s->buf_size * s->bufs_per_mdl;
                break;
        }

        cx18_load_queues(s);
}

int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
{
        u32 data[MAX_MB_ARGUMENTS];
        struct cx18 *cx = s->cx;
        int captype = 0;
        struct cx18_stream *s_idx;

        if (!cx18_stream_enabled(s))
                return -EINVAL;

        CX18_DEBUG_INFO("Start encoder stream %s\n", s->name);

        switch (s->type) {
        case CX18_ENC_STREAM_TYPE_MPG:
                captype = CAPTURE_CHANNEL_TYPE_MPEG;
                cx->mpg_data_received = cx->vbi_data_inserted = 0;
                cx->dualwatch_jiffies = jiffies;
                cx->dualwatch_stereo_mode = v4l2_ctrl_g_ctrl(cx->cxhdl.audio_mode);
                cx->search_pack_header = 0;
                break;

        case CX18_ENC_STREAM_TYPE_IDX:
                captype = CAPTURE_CHANNEL_TYPE_INDEX;
                break;
        case CX18_ENC_STREAM_TYPE_TS:
                captype = CAPTURE_CHANNEL_TYPE_TS;
                break;
        case CX18_ENC_STREAM_TYPE_YUV:
                captype = CAPTURE_CHANNEL_TYPE_YUV;
                break;
        case CX18_ENC_STREAM_TYPE_PCM:
                captype = CAPTURE_CHANNEL_TYPE_PCM;
                break;
        case CX18_ENC_STREAM_TYPE_VBI:
#ifdef CX18_ENCODER_PARSES_SLICED
                captype = cx18_raw_vbi(cx) ?
                     CAPTURE_CHANNEL_TYPE_VBI : CAPTURE_CHANNEL_TYPE_SLICED_VBI;
#else
                /*
                 * Currently we set things up so that Sliced VBI from the
                 * digitizer is handled as Raw VBI by the encoder
                 */
                captype = CAPTURE_CHANNEL_TYPE_VBI;
#endif
                cx->vbi.frame = 0;
                cx->vbi.inserted_frame = 0;
                memset(cx->vbi.sliced_mpeg_size,
                        0, sizeof(cx->vbi.sliced_mpeg_size));
                break;
        default:
                return -EINVAL;
        }

        /* Clear Streamoff flags in case left from last capture */
        clear_bit(CX18_F_S_STREAMOFF, &s->s_flags);

        cx18_vapi_result(cx, data, CX18_CREATE_TASK, 1, CPU_CMD_MASK_CAPTURE);
        s->handle = data[0];
        cx18_vapi(cx, CX18_CPU_SET_CHANNEL_TYPE, 2, s->handle, captype);

        /*
         * For everything but CAPTURE_CHANNEL_TYPE_TS, play it safe and
         * set up all the parameters, as it is not obvious which parameters the
         * firmware shares across capture channel types and which it does not.
         *
         * Some of the cx18_vapi() calls below apply to only certain capture
         * channel types.  We're hoping there's no harm in calling most of them
         * anyway, as long as the values are all consistent.  Setting some
         * shared parameters will have no effect once an analog capture channel
         * has started streaming.
         */
        if (captype != CAPTURE_CHANNEL_TYPE_TS) {
                cx18_vapi(cx, CX18_CPU_SET_VER_CROP_LINE, 2, s->handle, 0);
                cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 3, 1);
                cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 8, 0);
                cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 4, 1);

                /*
                 * Audio related reset according to
                 * Documentation/driver-api/media/drivers/cx2341x-devel.rst
                 */
                if (atomic_read(&cx->ana_capturing) == 0)
                        cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 2,
                                  s->handle, 12);

                /*
                 * Number of lines for Field 1 & Field 2 according to
                 * Documentation/driver-api/media/drivers/cx2341x-devel.rst
                 * Field 1 is 312 for 625 line systems in BT.656
                 * Field 2 is 313 for 625 line systems in BT.656
                 */
                cx18_vapi(cx, CX18_CPU_SET_CAPTURE_LINE_NO, 3,
                          s->handle, 312, 313);

                if (cx->v4l2_cap & V4L2_CAP_VBI_CAPTURE)
                        cx18_vbi_setup(s);

                /*
                 * Select to receive I, P, and B frame index entries, if the
                 * index stream is enabled.  Otherwise disable index entry
                 * generation.
                 */
                s_idx = &cx->streams[CX18_ENC_STREAM_TYPE_IDX];
                cx18_vapi_result(cx, data, CX18_CPU_SET_INDEXTABLE, 2,
                                 s->handle, cx18_stream_enabled(s_idx) ? 7 : 0);

                /* Call out to the common CX2341x API setup for user controls */
                cx->cxhdl.priv = s;
                cx2341x_handler_setup(&cx->cxhdl);

                /*
                 * When starting a capture and we're set for radio,
                 * ensure the video is muted, despite the user control.
                 */
                if (!cx->cxhdl.video_mute &&
                    test_bit(CX18_F_I_RADIO_USER, &cx->i_flags))
                        cx18_vapi(cx, CX18_CPU_SET_VIDEO_MUTE, 2, s->handle,
                          (v4l2_ctrl_g_ctrl(cx->cxhdl.video_mute_yuv) << 8) | 1);

                /* Enable the Video Format Converter for UYVY 4:2:2 support,
                 * rather than the default HM12 Macroblovk 4:2:0 support.
                 */
                if (captype == CAPTURE_CHANNEL_TYPE_YUV) {
                        if (s->pixelformat == V4L2_PIX_FMT_UYVY)
                                cx18_vapi(cx, CX18_CPU_SET_VFC_PARAM, 2,
                                        s->handle, 1);
                        else
                                /* If in doubt, default to HM12 */
                                cx18_vapi(cx, CX18_CPU_SET_VFC_PARAM, 2,
                                        s->handle, 0);
                }
        }

        if (atomic_read(&cx->tot_capturing) == 0) {
                cx2341x_handler_set_busy(&cx->cxhdl, 1);
                clear_bit(CX18_F_I_EOS, &cx->i_flags);
                cx18_write_reg(cx, 7, CX18_DSP0_INTERRUPT_MASK);
        }

        cx18_vapi(cx, CX18_CPU_DE_SET_MDL_ACK, 3, s->handle,
                (void __iomem *)&cx->scb->cpu_mdl_ack[s->type][0] - cx->enc_mem,
                (void __iomem *)&cx->scb->cpu_mdl_ack[s->type][1] - cx->enc_mem);

        /* Init all the cpu_mdls for this stream */
        cx18_stream_configure_mdls(s);
        _cx18_stream_load_fw_queue(s);

        /* begin_capture */
        if (cx18_vapi(cx, CX18_CPU_CAPTURE_START, 1, s->handle)) {
                CX18_DEBUG_WARN("Error starting capture!\n");
                /* Ensure we're really not capturing before releasing MDLs */
                set_bit(CX18_F_S_STOPPING, &s->s_flags);
                if (s->type == CX18_ENC_STREAM_TYPE_MPG)
                        cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, 1);
                else
                        cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 1, s->handle);
                clear_bit(CX18_F_S_STREAMING, &s->s_flags);
                /* FIXME - CX18_F_S_STREAMOFF as well? */
                cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle);
                cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
                s->handle = CX18_INVALID_TASK_HANDLE;
                clear_bit(CX18_F_S_STOPPING, &s->s_flags);
                if (atomic_read(&cx->tot_capturing) == 0) {
                        set_bit(CX18_F_I_EOS, &cx->i_flags);
                        cx18_write_reg(cx, 5, CX18_DSP0_INTERRUPT_MASK);
                }
                return -EINVAL;
        }

        /* you're live! sit back and await interrupts :) */
        if (captype != CAPTURE_CHANNEL_TYPE_TS)
                atomic_inc(&cx->ana_capturing);
        atomic_inc(&cx->tot_capturing);
        return 0;
}
EXPORT_SYMBOL(cx18_start_v4l2_encode_stream);

void cx18_stop_all_captures(struct cx18 *cx)
{
        int i;

        for (i = CX18_MAX_STREAMS - 1; i >= 0; i--) {
                struct cx18_stream *s = &cx->streams[i];

                if (!cx18_stream_enabled(s))
                        continue;
                if (test_bit(CX18_F_S_STREAMING, &s->s_flags))
                        cx18_stop_v4l2_encode_stream(s, 0);
        }
}

int cx18_stop_v4l2_encode_stream(struct cx18_stream *s, int gop_end)
{
        struct cx18 *cx = s->cx;

        if (!cx18_stream_enabled(s))
                return -EINVAL;

        /* This function assumes that you are allowed to stop the capture
           and that we are actually capturing */

        CX18_DEBUG_INFO("Stop Capture\n");

        if (atomic_read(&cx->tot_capturing) == 0)
                return 0;

        set_bit(CX18_F_S_STOPPING, &s->s_flags);
        if (s->type == CX18_ENC_STREAM_TYPE_MPG)
                cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, !gop_end);
        else
                cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 1, s->handle);

        if (s->type == CX18_ENC_STREAM_TYPE_MPG && gop_end) {
                CX18_INFO("ignoring gop_end: not (yet?) supported by the firmware\n");
        }

        if (s->type != CX18_ENC_STREAM_TYPE_TS)
                atomic_dec(&cx->ana_capturing);
        atomic_dec(&cx->tot_capturing);

        /* Clear capture and no-read bits */
        clear_bit(CX18_F_S_STREAMING, &s->s_flags);

        /* Tell the CX23418 it can't use our buffers anymore */
        cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle);

        cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
        s->handle = CX18_INVALID_TASK_HANDLE;
        clear_bit(CX18_F_S_STOPPING, &s->s_flags);

        if (atomic_read(&cx->tot_capturing) > 0)
                return 0;

        cx2341x_handler_set_busy(&cx->cxhdl, 0);
        cx18_write_reg(cx, 5, CX18_DSP0_INTERRUPT_MASK);
        wake_up(&s->waitq);

        return 0;
}
EXPORT_SYMBOL(cx18_stop_v4l2_encode_stream);

u32 cx18_find_handle(struct cx18 *cx)
{
        int i;

        /* find first available handle to be used for global settings */
        for (i = 0; i < CX18_MAX_STREAMS; i++) {
                struct cx18_stream *s = &cx->streams[i];

                if (s->video_dev.v4l2_dev && (s->handle != CX18_INVALID_TASK_HANDLE))
                        return s->handle;
        }
        return CX18_INVALID_TASK_HANDLE;
}

struct cx18_stream *cx18_handle_to_stream(struct cx18 *cx, u32 handle)
{
        int i;
        struct cx18_stream *s;

        if (handle == CX18_INVALID_TASK_HANDLE)
                return NULL;

        for (i = 0; i < CX18_MAX_STREAMS; i++) {
                s = &cx->streams[i];
                if (s->handle != handle)
                        continue;
                if (cx18_stream_enabled(s))
                        return s;
        }
        return NULL;
}