// SPDX-License-Identifier: GPL-2.0-only
/*
 * vivid-kthread-cap.h - video/vbi capture thread support functions.
 *
 * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/font.h>
#include <linux/mutex.h>
#include <linux/videodev2.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/random.h>
#include <linux/v4l2-dv-timings.h>
#include <asm/div64.h>
#include <media/videobuf2-vmalloc.h>
#include <media/v4l2-dv-timings.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
#include <media/v4l2-rect.h>

#include "vivid-core.h"
#include "vivid-vid-common.h"
#include "vivid-vid-cap.h"
#include "vivid-vid-out.h"
#include "vivid-radio-common.h"
#include "vivid-radio-rx.h"
#include "vivid-radio-tx.h"
#include "vivid-sdr-cap.h"
#include "vivid-vbi-cap.h"
#include "vivid-vbi-out.h"
#include "vivid-osd.h"
#include "vivid-ctrls.h"
#include "vivid-kthread-cap.h"
#include "vivid-meta-cap.h"

static inline v4l2_std_id vivid_get_std_cap(const struct vivid_dev *dev)
{
        if (vivid_is_sdtv_cap(dev))
                return dev->std_cap[dev->input];
        return 0;
}

static void copy_pix(struct vivid_dev *dev, int win_y, int win_x,
                        u16 *cap, const u16 *osd)
{
        u16 out;
        int left = dev->overlay_out_left;
        int top = dev->overlay_out_top;
        int fb_x = win_x + left;
        int fb_y = win_y + top;
        int i;

        out = *cap;
        *cap = *osd;
        if (dev->bitmap_out) {
                const u8 *p = dev->bitmap_out;
                unsigned stride = (dev->compose_out.width + 7) / 8;

                win_x -= dev->compose_out.left;
                win_y -= dev->compose_out.top;
                if (!(p[stride * win_y + win_x / 8] & (1 << (win_x & 7))))
                        return;
        }

        for (i = 0; i < dev->clipcount_out; i++) {
                struct v4l2_rect *r = &dev->clips_out[i].c;

                if (fb_y >= r->top && fb_y < r->top + r->height &&
                    fb_x >= r->left && fb_x < r->left + r->width)
                        return;
        }
        if ((dev->fbuf_out_flags & V4L2_FBUF_FLAG_CHROMAKEY) &&
            *osd != dev->chromakey_out)
                return;
        if ((dev->fbuf_out_flags & V4L2_FBUF_FLAG_SRC_CHROMAKEY) &&
            out == dev->chromakey_out)
                return;
        if (dev->fmt_cap->alpha_mask) {
                if ((dev->fbuf_out_flags & V4L2_FBUF_FLAG_GLOBAL_ALPHA) &&
                    dev->global_alpha_out)
                        return;
                if ((dev->fbuf_out_flags & V4L2_FBUF_FLAG_LOCAL_ALPHA) &&
                    *cap & dev->fmt_cap->alpha_mask)
                        return;
                if ((dev->fbuf_out_flags & V4L2_FBUF_FLAG_LOCAL_INV_ALPHA) &&
                    !(*cap & dev->fmt_cap->alpha_mask))
                        return;
        }
        *cap = out;
}

static void blend_line(struct vivid_dev *dev, unsigned y_offset, unsigned x_offset,
                u8 *vcapbuf, const u8 *vosdbuf,
                unsigned width, unsigned pixsize)
{
        unsigned x;

        for (x = 0; x < width; x++, vcapbuf += pixsize, vosdbuf += pixsize) {
                copy_pix(dev, y_offset, x_offset + x,
                         (u16 *)vcapbuf, (const u16 *)vosdbuf);
        }
}

static void scale_line(const u8 *src, u8 *dst, unsigned srcw, unsigned dstw, unsigned twopixsize)
{
        /* Coarse scaling with Bresenham */
        unsigned int_part;
        unsigned fract_part;
        unsigned src_x = 0;
        unsigned error = 0;
        unsigned x;

        /*
         * We always combine two pixels to prevent color bleed in the packed
         * yuv case.
         */
        srcw /= 2;
        dstw /= 2;
        int_part = srcw / dstw;
        fract_part = srcw % dstw;
        for (x = 0; x < dstw; x++, dst += twopixsize) {
                memcpy(dst, src + src_x * twopixsize, twopixsize);
                src_x += int_part;
                error += fract_part;
                if (error >= dstw) {
                        error -= dstw;
                        src_x++;
                }
        }
}

/*
 * Precalculate the rectangles needed to perform video looping:
 *
 * The nominal pipeline is that the video output buffer is cropped by
 * crop_out, scaled to compose_out, overlaid with the output overlay,
 * cropped on the capture side by crop_cap and scaled again to the video
 * capture buffer using compose_cap.
 *
 * To keep things efficient we calculate the intersection of compose_out
 * and crop_cap (since that's the only part of the video that will
 * actually end up in the capture buffer), determine which part of the
 * video output buffer that is and which part of the video capture buffer
 * so we can scale the video straight from the output buffer to the capture
 * buffer without any intermediate steps.
 *
 * If we need to deal with an output overlay, then there is no choice and
 * that intermediate step still has to be taken. For the output overlay
 * support we calculate the intersection of the framebuffer and the overlay
 * window (which may be partially or wholly outside of the framebuffer
 * itself) and the intersection of that with loop_vid_copy (i.e. the part of
 * the actual looped video that will be overlaid). The result is calculated
 * both in framebuffer coordinates (loop_fb_copy) and compose_out coordinates
 * (loop_vid_overlay). Finally calculate the part of the capture buffer that
 * will receive that overlaid video.
 */
static void vivid_precalc_copy_rects(struct vivid_dev *dev)
{
        /* Framebuffer rectangle */
        struct v4l2_rect r_fb = {
                0, 0, dev->display_width, dev->display_height
        };
        /* Overlay window rectangle in framebuffer coordinates */
        struct v4l2_rect r_overlay = {
                dev->overlay_out_left, dev->overlay_out_top,
                dev->compose_out.width, dev->compose_out.height
        };

        v4l2_rect_intersect(&dev->loop_vid_copy, &dev->crop_cap, &dev->compose_out);

        dev->loop_vid_out = dev->loop_vid_copy;
        v4l2_rect_scale(&dev->loop_vid_out, &dev->compose_out, &dev->crop_out);
        dev->loop_vid_out.left += dev->crop_out.left;
        dev->loop_vid_out.top += dev->crop_out.top;

        dev->loop_vid_cap = dev->loop_vid_copy;
        v4l2_rect_scale(&dev->loop_vid_cap, &dev->crop_cap, &dev->compose_cap);

        dprintk(dev, 1,
                "loop_vid_copy: %dx%d@%dx%d loop_vid_out: %dx%d@%dx%d loop_vid_cap: %dx%d@%dx%d\n",
                dev->loop_vid_copy.width, dev->loop_vid_copy.height,
                dev->loop_vid_copy.left, dev->loop_vid_copy.top,
                dev->loop_vid_out.width, dev->loop_vid_out.height,
                dev->loop_vid_out.left, dev->loop_vid_out.top,
                dev->loop_vid_cap.width, dev->loop_vid_cap.height,
                dev->loop_vid_cap.left, dev->loop_vid_cap.top);

        v4l2_rect_intersect(&r_overlay, &r_fb, &r_overlay);

        /* shift r_overlay to the same origin as compose_out */
        r_overlay.left += dev->compose_out.left - dev->overlay_out_left;
        r_overlay.top += dev->compose_out.top - dev->overlay_out_top;

        v4l2_rect_intersect(&dev->loop_vid_overlay, &r_overlay, &dev->loop_vid_copy);
        dev->loop_fb_copy = dev->loop_vid_overlay;

        /* shift dev->loop_fb_copy back again to the fb origin */
        dev->loop_fb_copy.left -= dev->compose_out.left - dev->overlay_out_left;
        dev->loop_fb_copy.top -= dev->compose_out.top - dev->overlay_out_top;

        dev->loop_vid_overlay_cap = dev->loop_vid_overlay;
        v4l2_rect_scale(&dev->loop_vid_overlay_cap, &dev->crop_cap, &dev->compose_cap);

        dprintk(dev, 1,
                "loop_fb_copy: %dx%d@%dx%d loop_vid_overlay: %dx%d@%dx%d loop_vid_overlay_cap: %dx%d@%dx%d\n",
                dev->loop_fb_copy.width, dev->loop_fb_copy.height,
                dev->loop_fb_copy.left, dev->loop_fb_copy.top,
                dev->loop_vid_overlay.width, dev->loop_vid_overlay.height,
                dev->loop_vid_overlay.left, dev->loop_vid_overlay.top,
                dev->loop_vid_overlay_cap.width, dev->loop_vid_overlay_cap.height,
                dev->loop_vid_overlay_cap.left, dev->loop_vid_overlay_cap.top);
}

static void *plane_vaddr(struct tpg_data *tpg, struct vivid_buffer *buf,
                         unsigned p, unsigned bpl[TPG_MAX_PLANES], unsigned h)
{
        unsigned i;
        void *vbuf;

        if (p == 0 || tpg_g_buffers(tpg) > 1)
                return vb2_plane_vaddr(&buf->vb.vb2_buf, p);
        vbuf = vb2_plane_vaddr(&buf->vb.vb2_buf, 0);
        for (i = 0; i < p; i++)
                vbuf += bpl[i] * h / tpg->vdownsampling[i];
        return vbuf;
}

static noinline_for_stack int vivid_copy_buffer(struct vivid_dev *dev, unsigned p,
                u8 *vcapbuf, struct vivid_buffer *vid_cap_buf)
{
        bool blank = dev->must_blank[vid_cap_buf->vb.vb2_buf.index];
        struct tpg_data *tpg = &dev->tpg;
        struct vivid_buffer *vid_out_buf = NULL;
        unsigned vdiv = dev->fmt_out->vdownsampling[p];
        unsigned twopixsize = tpg_g_twopixelsize(tpg, p);
        unsigned img_width = tpg_hdiv(tpg, p, dev->compose_cap.width);
        unsigned img_height = dev->compose_cap.height;
        unsigned stride_cap = tpg->bytesperline[p];
        unsigned stride_out = dev->bytesperline_out[p];
        unsigned stride_osd = dev->display_byte_stride;
        unsigned hmax = (img_height * tpg->perc_fill) / 100;
        u8 *voutbuf;
        u8 *vosdbuf = NULL;
        unsigned y;
        bool blend = dev->bitmap_out || dev->clipcount_out || dev->fbuf_out_flags;
        /* Coarse scaling with Bresenham */
        unsigned vid_out_int_part;
        unsigned vid_out_fract_part;
        unsigned vid_out_y = 0;
        unsigned vid_out_error = 0;
        unsigned vid_overlay_int_part = 0;
        unsigned vid_overlay_fract_part = 0;
        unsigned vid_overlay_y = 0;
        unsigned vid_overlay_error = 0;
        unsigned vid_cap_left = tpg_hdiv(tpg, p, dev->loop_vid_cap.left);
        unsigned vid_cap_right;
        bool quick;

        vid_out_int_part = dev->loop_vid_out.height / dev->loop_vid_cap.height;
        vid_out_fract_part = dev->loop_vid_out.height % dev->loop_vid_cap.height;

        if (!list_empty(&dev->vid_out_active))
                vid_out_buf = list_entry(dev->vid_out_active.next,
                                         struct vivid_buffer, list);
        if (vid_out_buf == NULL)
                return -ENODATA;

        vid_cap_buf->vb.field = vid_out_buf->vb.field;

        voutbuf = plane_vaddr(tpg, vid_out_buf, p,
                              dev->bytesperline_out, dev->fmt_out_rect.height);
        if (p < dev->fmt_out->buffers)
                voutbuf += vid_out_buf->vb.vb2_buf.planes[p].data_offset;
        voutbuf += tpg_hdiv(tpg, p, dev->loop_vid_out.left) +
                (dev->loop_vid_out.top / vdiv) * stride_out;
        vcapbuf += tpg_hdiv(tpg, p, dev->compose_cap.left) +
                (dev->compose_cap.top / vdiv) * stride_cap;

        if (dev->loop_vid_copy.width == 0 || dev->loop_vid_copy.height == 0) {
                /*
                 * If there is nothing to copy, then just fill the capture window
                 * with black.
                 */
                for (y = 0; y < hmax / vdiv; y++, vcapbuf += stride_cap)
                        memcpy(vcapbuf, tpg->black_line[p], img_width);
                return 0;
        }

        if (dev->overlay_out_enabled &&
            dev->loop_vid_overlay.width && dev->loop_vid_overlay.height) {
                vosdbuf = dev->video_vbase;
                vosdbuf += (dev->loop_fb_copy.left * twopixsize) / 2 +
                           dev->loop_fb_copy.top * stride_osd;
                vid_overlay_int_part = dev->loop_vid_overlay.height /
                                       dev->loop_vid_overlay_cap.height;
                vid_overlay_fract_part = dev->loop_vid_overlay.height %
                                         dev->loop_vid_overlay_cap.height;
        }

        vid_cap_right = tpg_hdiv(tpg, p, dev->loop_vid_cap.left + dev->loop_vid_cap.width);
        /* quick is true if no video scaling is needed */
        quick = dev->loop_vid_out.width == dev->loop_vid_cap.width;

        dev->cur_scaled_line = dev->loop_vid_out.height;
        for (y = 0; y < hmax; y += vdiv, vcapbuf += stride_cap) {
                /* osdline is true if this line requires overlay blending */
                bool osdline = vosdbuf && y >= dev->loop_vid_overlay_cap.top &&
                          y < dev->loop_vid_overlay_cap.top + dev->loop_vid_overlay_cap.height;

                /*
                 * If this line of the capture buffer doesn't get any video, then
                 * just fill with black.
                 */
                if (y < dev->loop_vid_cap.top ||
                    y >= dev->loop_vid_cap.top + dev->loop_vid_cap.height) {
                        memcpy(vcapbuf, tpg->black_line[p], img_width);
                        continue;
                }

                /* fill the left border with black */
                if (dev->loop_vid_cap.left)
                        memcpy(vcapbuf, tpg->black_line[p], vid_cap_left);

                /* fill the right border with black */
                if (vid_cap_right < img_width)
                        memcpy(vcapbuf + vid_cap_right, tpg->black_line[p],
                                img_width - vid_cap_right);

                if (quick && !osdline) {
                        memcpy(vcapbuf + vid_cap_left,
                               voutbuf + vid_out_y * stride_out,
                               tpg_hdiv(tpg, p, dev->loop_vid_cap.width));
                        goto update_vid_out_y;
                }
                if (dev->cur_scaled_line == vid_out_y) {
                        memcpy(vcapbuf + vid_cap_left, dev->scaled_line,
                               tpg_hdiv(tpg, p, dev->loop_vid_cap.width));
                        goto update_vid_out_y;
                }
                if (!osdline) {
                        scale_line(voutbuf + vid_out_y * stride_out, dev->scaled_line,
                                tpg_hdiv(tpg, p, dev->loop_vid_out.width),
                                tpg_hdiv(tpg, p, dev->loop_vid_cap.width),
                                tpg_g_twopixelsize(tpg, p));
                } else {
                        /*
                         * Offset in bytes within loop_vid_copy to the start of the
                         * loop_vid_overlay rectangle.
                         */
                        unsigned offset =
                                ((dev->loop_vid_overlay.left - dev->loop_vid_copy.left) *
                                 twopixsize) / 2;
                        u8 *osd = vosdbuf + vid_overlay_y * stride_osd;

                        scale_line(voutbuf + vid_out_y * stride_out, dev->blended_line,
                                dev->loop_vid_out.width, dev->loop_vid_copy.width,
                                tpg_g_twopixelsize(tpg, p));
                        if (blend)
                                blend_line(dev, vid_overlay_y + dev->loop_vid_overlay.top,
                                           dev->loop_vid_overlay.left,
                                           dev->blended_line + offset, osd,
                                           dev->loop_vid_overlay.width, twopixsize / 2);
                        else
                                memcpy(dev->blended_line + offset,
                                       osd, (dev->loop_vid_overlay.width * twopixsize) / 2);
                        scale_line(dev->blended_line, dev->scaled_line,
                                        dev->loop_vid_copy.width, dev->loop_vid_cap.width,
                                        tpg_g_twopixelsize(tpg, p));
                }
                dev->cur_scaled_line = vid_out_y;
                memcpy(vcapbuf + vid_cap_left, dev->scaled_line,
                       tpg_hdiv(tpg, p, dev->loop_vid_cap.width));

update_vid_out_y:
                if (osdline) {
                        vid_overlay_y += vid_overlay_int_part;
                        vid_overlay_error += vid_overlay_fract_part;
                        if (vid_overlay_error >= dev->loop_vid_overlay_cap.height) {
                                vid_overlay_error -= dev->loop_vid_overlay_cap.height;
                                vid_overlay_y++;
                        }
                }
                vid_out_y += vid_out_int_part;
                vid_out_error += vid_out_fract_part;
                if (vid_out_error >= dev->loop_vid_cap.height / vdiv) {
                        vid_out_error -= dev->loop_vid_cap.height / vdiv;
                        vid_out_y++;
                }
        }

        if (!blank)
                return 0;
        for (; y < img_height; y += vdiv, vcapbuf += stride_cap)
                memcpy(vcapbuf, tpg->contrast_line[p], img_width);
        return 0;
}

static void vivid_fillbuff(struct vivid_dev *dev, struct vivid_buffer *buf)
{
        struct tpg_data *tpg = &dev->tpg;
        unsigned factor = V4L2_FIELD_HAS_T_OR_B(dev->field_cap) ? 2 : 1;
        unsigned line_height = 16 / factor;
        bool is_tv = vivid_is_sdtv_cap(dev);
        bool is_60hz = is_tv && (dev->std_cap[dev->input] & V4L2_STD_525_60);
        unsigned p;
        int line = 1;
        u8 *basep[TPG_MAX_PLANES][2];
        unsigned ms;
        char str[100];
        s32 gain;
        bool is_loop = false;

        if (dev->loop_video && dev->can_loop_video &&
                ((vivid_is_svid_cap(dev) &&
                !VIVID_INVALID_SIGNAL(dev->std_signal_mode[dev->input])) ||
                (vivid_is_hdmi_cap(dev) &&
                !VIVID_INVALID_SIGNAL(dev->dv_timings_signal_mode[dev->input]))))
                is_loop = true;

        buf->vb.sequence = dev->vid_cap_seq_count;
        if (dev->field_cap == V4L2_FIELD_ALTERNATE) {
                /*
                 * 60 Hz standards start with the bottom field, 50 Hz standards
                 * with the top field. So if the 0-based seq_count is even,
                 * then the field is TOP for 50 Hz and BOTTOM for 60 Hz
                 * standards.
                 */
                buf->vb.field = ((dev->vid_cap_seq_count & 1) ^ is_60hz) ?
                        V4L2_FIELD_BOTTOM : V4L2_FIELD_TOP;
                /*
                 * The sequence counter counts frames, not fields. So divide
                 * by two.
                 */
                buf->vb.sequence /= 2;
        } else {
                buf->vb.field = dev->field_cap;
        }
        tpg_s_field(tpg, buf->vb.field,
                    dev->field_cap == V4L2_FIELD_ALTERNATE);
        tpg_s_perc_fill_blank(tpg, dev->must_blank[buf->vb.vb2_buf.index]);

        vivid_precalc_copy_rects(dev);

        for (p = 0; p < tpg_g_planes(tpg); p++) {
                void *vbuf = plane_vaddr(tpg, buf, p,
                                         tpg->bytesperline, tpg->buf_height);

                /*
                 * The first plane of a multiplanar format has a non-zero
                 * data_offset. This helps testing whether the application
                 * correctly supports non-zero data offsets.
                 */
                if (p < tpg_g_buffers(tpg) && dev->fmt_cap->data_offset[p]) {
                        memset(vbuf, dev->fmt_cap->data_offset[p] & 0xff,
                               dev->fmt_cap->data_offset[p]);
                        vbuf += dev->fmt_cap->data_offset[p];
                }
                tpg_calc_text_basep(tpg, basep, p, vbuf);
                if (!is_loop || vivid_copy_buffer(dev, p, vbuf, buf))
                        tpg_fill_plane_buffer(tpg, vivid_get_std_cap(dev),
                                        p, vbuf);
        }
        dev->must_blank[buf->vb.vb2_buf.index] = false;

        /* Updates stream time, only update at the start of a new frame. */
        if (dev->field_cap != V4L2_FIELD_ALTERNATE ||
                        (dev->vid_cap_seq_count & 1) == 0)
                dev->ms_vid_cap =
                        jiffies_to_msecs(jiffies - dev->jiffies_vid_cap);

        ms = dev->ms_vid_cap;
        if (dev->osd_mode <= 1) {
                snprintf(str, sizeof(str), " %02d:%02d:%02d:%03d %u%s",
                                (ms / (60 * 60 * 1000)) % 24,
                                (ms / (60 * 1000)) % 60,
                                (ms / 1000) % 60,
                                ms % 1000,
                                buf->vb.sequence,
                                (dev->field_cap == V4L2_FIELD_ALTERNATE) ?
                                        (buf->vb.field == V4L2_FIELD_TOP ?
                                         " top" : " bottom") : "");
                tpg_gen_text(tpg, basep, line++ * line_height, 16, str);
        }
        if (dev->osd_mode == 0) {
                snprintf(str, sizeof(str), " %dx%d, input %d ",
                                dev->src_rect.width, dev->src_rect.height, dev->input);
                tpg_gen_text(tpg, basep, line++ * line_height, 16, str);

                gain = v4l2_ctrl_g_ctrl(dev->gain);
                mutex_lock(dev->ctrl_hdl_user_vid.lock);
                snprintf(str, sizeof(str),
                        " brightness %3d, contrast %3d, saturation %3d, hue %d ",
                        dev->brightness->cur.val,
                        dev->contrast->cur.val,
                        dev->saturation->cur.val,
                        dev->hue->cur.val);
                tpg_gen_text(tpg, basep, line++ * line_height, 16, str);
                snprintf(str, sizeof(str),
                        " autogain %d, gain %3d, alpha 0x%02x ",
                        dev->autogain->cur.val, gain, dev->alpha->cur.val);
                mutex_unlock(dev->ctrl_hdl_user_vid.lock);
                tpg_gen_text(tpg, basep, line++ * line_height, 16, str);
                mutex_lock(dev->ctrl_hdl_user_aud.lock);
                snprintf(str, sizeof(str),
                        " volume %3d, mute %d ",
                        dev->volume->cur.val, dev->mute->cur.val);
                mutex_unlock(dev->ctrl_hdl_user_aud.lock);
                tpg_gen_text(tpg, basep, line++ * line_height, 16, str);
                mutex_lock(dev->ctrl_hdl_user_gen.lock);
                snprintf(str, sizeof(str), " int32 %d, int64 %lld, bitmask %08x ",
                        dev->int32->cur.val,
                        *dev->int64->p_cur.p_s64,
                        dev->bitmask->cur.val);
                tpg_gen_text(tpg, basep, line++ * line_height, 16, str);
                snprintf(str, sizeof(str), " boolean %d, menu %s, string \"%s\" ",
                        dev->boolean->cur.val,
                        dev->menu->qmenu[dev->menu->cur.val],
                        dev->string->p_cur.p_char);
                tpg_gen_text(tpg, basep, line++ * line_height, 16, str);
                snprintf(str, sizeof(str), " integer_menu %lld, value %d ",
                        dev->int_menu->qmenu_int[dev->int_menu->cur.val],
                        dev->int_menu->cur.val);
                mutex_unlock(dev->ctrl_hdl_user_gen.lock);
                tpg_gen_text(tpg, basep, line++ * line_height, 16, str);
                if (dev->button_pressed) {
                        dev->button_pressed--;
                        snprintf(str, sizeof(str), " button pressed!");
                        tpg_gen_text(tpg, basep, line++ * line_height, 16, str);
                }
                if (dev->osd[0]) {
                        if (vivid_is_hdmi_cap(dev)) {
                                snprintf(str, sizeof(str),
                                         " OSD \"%s\"", dev->osd);
                                tpg_gen_text(tpg, basep, line++ * line_height,
                                             16, str);
                        }
                        if (dev->osd_jiffies &&
                            time_is_before_jiffies(dev->osd_jiffies + 5 * HZ)) {
                                dev->osd[0] = 0;
                                dev->osd_jiffies = 0;
                        }
                }
        }
}

/*
 * Return true if this pixel coordinate is a valid video pixel.
 */
static bool valid_pix(struct vivid_dev *dev, int win_y, int win_x, int fb_y, int fb_x)
{
        int i;

        if (dev->bitmap_cap) {
                /*
                 * Only if the corresponding bit in the bitmap is set can
                 * the video pixel be shown. Coordinates are relative to
                 * the overlay window set by VIDIOC_S_FMT.
                 */
                const u8 *p = dev->bitmap_cap;
                unsigned stride = (dev->compose_cap.width + 7) / 8;

                if (!(p[stride * win_y + win_x / 8] & (1 << (win_x & 7))))
                        return false;
        }

        for (i = 0; i < dev->clipcount_cap; i++) {
                /*
                 * Only if the framebuffer coordinate is not in any of the
                 * clip rectangles will be video pixel be shown.
                 */
                struct v4l2_rect *r = &dev->clips_cap[i].c;

                if (fb_y >= r->top && fb_y < r->top + r->height &&
                    fb_x >= r->left && fb_x < r->left + r->width)
                        return false;
        }
        return true;
}

/*
 * Draw the image into the overlay buffer.
 * Note that the combination of overlay and multiplanar is not supported.
 */
static void vivid_overlay(struct vivid_dev *dev, struct vivid_buffer *buf)
{
        struct tpg_data *tpg = &dev->tpg;
        unsigned pixsize = tpg_g_twopixelsize(tpg, 0) / 2;
        void *vbase = dev->fb_vbase_cap;
        void *vbuf = vb2_plane_vaddr(&buf->vb.vb2_buf, 0);
        unsigned img_width = dev->compose_cap.width;
        unsigned img_height = dev->compose_cap.height;
        unsigned stride = tpg->bytesperline[0];
        /* if quick is true, then valid_pix() doesn't have to be called */
        bool quick = dev->bitmap_cap == NULL && dev->clipcount_cap == 0;
        int x, y, w, out_x = 0;

        /*
         * Overlay support is only supported for formats that have a twopixelsize
         * that's >= 2. Warn and bail out if that's not the case.
         */
        if (WARN_ON(pixsize == 0))
                return;
        if ((dev->overlay_cap_field == V4L2_FIELD_TOP ||
             dev->overlay_cap_field == V4L2_FIELD_BOTTOM) &&
            dev->overlay_cap_field != buf->vb.field)
                return;

        vbuf += dev->compose_cap.left * pixsize + dev->compose_cap.top * stride;
        x = dev->overlay_cap_left;
        w = img_width;
        if (x < 0) {
                out_x = -x;
                w = w - out_x;
                x = 0;
        } else {
                w = dev->fb_cap.fmt.width - x;
                if (w > img_width)
                        w = img_width;
        }
        if (w <= 0)
                return;
        if (dev->overlay_cap_top >= 0)
                vbase += dev->overlay_cap_top * dev->fb_cap.fmt.bytesperline;
        for (y = dev->overlay_cap_top;
             y < dev->overlay_cap_top + (int)img_height;
             y++, vbuf += stride) {
                int px;

                if (y < 0 || y > dev->fb_cap.fmt.height)
                        continue;
                if (quick) {
                        memcpy(vbase + x * pixsize,
                               vbuf + out_x * pixsize, w * pixsize);
                        vbase += dev->fb_cap.fmt.bytesperline;
                        continue;
                }
                for (px = 0; px < w; px++) {
                        if (!valid_pix(dev, y - dev->overlay_cap_top,
                                       px + out_x, y, px + x))
                                continue;
                        memcpy(vbase + (px + x) * pixsize,
                               vbuf + (px + out_x) * pixsize,
                               pixsize);
                }
                vbase += dev->fb_cap.fmt.bytesperline;
        }
}

static void vivid_cap_update_frame_period(struct vivid_dev *dev)
{
        u64 f_period;

        f_period = (u64)dev->timeperframe_vid_cap.numerator * 1000000000;
        if (WARN_ON(dev->timeperframe_vid_cap.denominator == 0))
                dev->timeperframe_vid_cap.denominator = 1;
        do_div(f_period, dev->timeperframe_vid_cap.denominator);
        if (dev->field_cap == V4L2_FIELD_ALTERNATE)
                f_period >>= 1;
        /*
         * If "End of Frame", then offset the exposure time by 0.9
         * of the frame period.
         */
        dev->cap_frame_eof_offset = f_period * 9;
        do_div(dev->cap_frame_eof_offset, 10);
        dev->cap_frame_period = f_period;
}

static noinline_for_stack void vivid_thread_vid_cap_tick(struct vivid_dev *dev,
                                                         int dropped_bufs)
{
        struct vivid_buffer *vid_cap_buf = NULL;
        struct vivid_buffer *vbi_cap_buf = NULL;
        struct vivid_buffer *meta_cap_buf = NULL;
        u64 f_time = 0;

        dprintk(dev, 1, "Video Capture Thread Tick\n");

        while (dropped_bufs-- > 1)
                tpg_update_mv_count(&dev->tpg,
                                dev->field_cap == V4L2_FIELD_NONE ||
                                dev->field_cap == V4L2_FIELD_ALTERNATE);

        /* Drop a certain percentage of buffers. */
        if (dev->perc_dropped_buffers &&
            prandom_u32_max(100) < dev->perc_dropped_buffers)
                goto update_mv;

        spin_lock(&dev->slock);
        if (!list_empty(&dev->vid_cap_active)) {
                vid_cap_buf = list_entry(dev->vid_cap_active.next, struct vivid_buffer, list);
                list_del(&vid_cap_buf->list);
        }
        if (!list_empty(&dev->vbi_cap_active)) {
                if (dev->field_cap != V4L2_FIELD_ALTERNATE ||
                    (dev->vbi_cap_seq_count & 1)) {
                        vbi_cap_buf = list_entry(dev->vbi_cap_active.next,
                                                 struct vivid_buffer, list);
                        list_del(&vbi_cap_buf->list);
                }
        }
        if (!list_empty(&dev->meta_cap_active)) {
                meta_cap_buf = list_entry(dev->meta_cap_active.next,
                                          struct vivid_buffer, list);
                list_del(&meta_cap_buf->list);
        }

        spin_unlock(&dev->slock);

        if (!vid_cap_buf && !vbi_cap_buf && !meta_cap_buf)
                goto update_mv;

        f_time = dev->cap_frame_period * dev->vid_cap_seq_count +
                 dev->cap_stream_start + dev->time_wrap_offset;

        if (vid_cap_buf) {
                v4l2_ctrl_request_setup(vid_cap_buf->vb.vb2_buf.req_obj.req,
                                        &dev->ctrl_hdl_vid_cap);
                /* Fill buffer */
                vivid_fillbuff(dev, vid_cap_buf);
                dprintk(dev, 1, "filled buffer %d\n",
                        vid_cap_buf->vb.vb2_buf.index);

                /* Handle overlay */
                if (dev->overlay_cap_owner && dev->fb_cap.base &&
                        dev->fb_cap.fmt.pixelformat == dev->fmt_cap->fourcc)
                        vivid_overlay(dev, vid_cap_buf);

                v4l2_ctrl_request_complete(vid_cap_buf->vb.vb2_buf.req_obj.req,
                                           &dev->ctrl_hdl_vid_cap);
                vb2_buffer_done(&vid_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
                                VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
                dprintk(dev, 2, "vid_cap buffer %d done\n",
                                vid_cap_buf->vb.vb2_buf.index);

                vid_cap_buf->vb.vb2_buf.timestamp = f_time;
                if (!dev->tstamp_src_is_soe)
                        vid_cap_buf->vb.vb2_buf.timestamp += dev->cap_frame_eof_offset;
        }

        if (vbi_cap_buf) {
                u64 vbi_period;

                v4l2_ctrl_request_setup(vbi_cap_buf->vb.vb2_buf.req_obj.req,
                                        &dev->ctrl_hdl_vbi_cap);
                if (dev->stream_sliced_vbi_cap)
                        vivid_sliced_vbi_cap_process(dev, vbi_cap_buf);
                else
                        vivid_raw_vbi_cap_process(dev, vbi_cap_buf);
                v4l2_ctrl_request_complete(vbi_cap_buf->vb.vb2_buf.req_obj.req,
                                           &dev->ctrl_hdl_vbi_cap);
                vb2_buffer_done(&vbi_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
                                VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
                dprintk(dev, 2, "vbi_cap %d done\n",
                                vbi_cap_buf->vb.vb2_buf.index);

                /* If capturing a VBI, offset by 0.05 */
                vbi_period = dev->cap_frame_period * 5;
                do_div(vbi_period, 100);
                vbi_cap_buf->vb.vb2_buf.timestamp = f_time + dev->cap_frame_eof_offset + vbi_period;
        }

        if (meta_cap_buf) {
                v4l2_ctrl_request_setup(meta_cap_buf->vb.vb2_buf.req_obj.req,
                                        &dev->ctrl_hdl_meta_cap);
                vivid_meta_cap_fillbuff(dev, meta_cap_buf, f_time);
                v4l2_ctrl_request_complete(meta_cap_buf->vb.vb2_buf.req_obj.req,
                                           &dev->ctrl_hdl_meta_cap);
                vb2_buffer_done(&meta_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
                                VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
                dprintk(dev, 2, "meta_cap %d done\n",
                        meta_cap_buf->vb.vb2_buf.index);
                meta_cap_buf->vb.vb2_buf.timestamp = f_time + dev->cap_frame_eof_offset;
        }

        dev->dqbuf_error = false;

update_mv:
        /* Update the test pattern movement counters */
        tpg_update_mv_count(&dev->tpg, dev->field_cap == V4L2_FIELD_NONE ||
                                       dev->field_cap == V4L2_FIELD_ALTERNATE);
}

static int vivid_thread_vid_cap(void *data)
{
        struct vivid_dev *dev = data;
        u64 numerators_since_start;
        u64 buffers_since_start;
        u64 next_jiffies_since_start;
        unsigned long jiffies_since_start;
        unsigned long cur_jiffies;
        unsigned wait_jiffies;
        unsigned numerator;
        unsigned denominator;
        int dropped_bufs;

        dprintk(dev, 1, "Video Capture Thread Start\n");

        set_freezable();

        /* Resets frame counters */
        dev->cap_seq_offset = 0;
        dev->cap_seq_count = 0;
        dev->cap_seq_resync = false;
        dev->jiffies_vid_cap = jiffies;
        dev->cap_stream_start = ktime_get_ns();
        vivid_cap_update_frame_period(dev);

        for (;;) {
                try_to_freeze();
                if (kthread_should_stop())
                        break;

                if (!mutex_trylock(&dev->mutex)) {
                        schedule();
                        continue;
                }

                cur_jiffies = jiffies;
                if (dev->cap_seq_resync) {
                        dev->jiffies_vid_cap = cur_jiffies;
                        dev->cap_seq_offset = dev->cap_seq_count + 1;
                        dev->cap_seq_count = 0;
                        dev->cap_stream_start += dev->cap_frame_period *
                                                 dev->cap_seq_offset;
                        vivid_cap_update_frame_period(dev);
                        dev->cap_seq_resync = false;
                }
                numerator = dev->timeperframe_vid_cap.numerator;
                denominator = dev->timeperframe_vid_cap.denominator;

                if (dev->field_cap == V4L2_FIELD_ALTERNATE)
                        denominator *= 2;

                /* Calculate the number of jiffies since we started streaming */
                jiffies_since_start = cur_jiffies - dev->jiffies_vid_cap;
                /* Get the number of buffers streamed since the start */
                buffers_since_start = (u64)jiffies_since_start * denominator +
                                      (HZ * numerator) / 2;
                do_div(buffers_since_start, HZ * numerator);

                /*
                 * After more than 0xf0000000 (rounded down to a multiple of
                 * 'jiffies-per-day' to ease jiffies_to_msecs calculation)
                 * jiffies have passed since we started streaming reset the
                 * counters and keep track of the sequence offset.
                 */
                if (jiffies_since_start > JIFFIES_RESYNC) {
                        dev->jiffies_vid_cap = cur_jiffies;
                        dev->cap_seq_offset = buffers_since_start;
                        buffers_since_start = 0;
                }
                dropped_bufs = buffers_since_start + dev->cap_seq_offset - dev->cap_seq_count;
                dev->cap_seq_count = buffers_since_start + dev->cap_seq_offset;
                dev->vid_cap_seq_count = dev->cap_seq_count - dev->vid_cap_seq_start;
                dev->vbi_cap_seq_count = dev->cap_seq_count - dev->vbi_cap_seq_start;
                dev->meta_cap_seq_count = dev->cap_seq_count - dev->meta_cap_seq_start;

                vivid_thread_vid_cap_tick(dev, dropped_bufs);

                /*
                 * Calculate the number of 'numerators' streamed since we started,
                 * including the current buffer.
                 */
                numerators_since_start = ++buffers_since_start * numerator;

                /* And the number of jiffies since we started */
                jiffies_since_start = jiffies - dev->jiffies_vid_cap;

                mutex_unlock(&dev->mutex);

                /*
                 * Calculate when that next buffer is supposed to start
                 * in jiffies since we started streaming.
                 */
                next_jiffies_since_start = numerators_since_start * HZ +
                                           denominator / 2;
                do_div(next_jiffies_since_start, denominator);
                /* If it is in the past, then just schedule asap */
                if (next_jiffies_since_start < jiffies_since_start)
                        next_jiffies_since_start = jiffies_since_start;

                wait_jiffies = next_jiffies_since_start - jiffies_since_start;
                while (jiffies - cur_jiffies < wait_jiffies &&
                       !kthread_should_stop())
                        schedule();
        }
        dprintk(dev, 1, "Video Capture Thread End\n");
        return 0;
}

static void vivid_grab_controls(struct vivid_dev *dev, bool grab)
{
        v4l2_ctrl_grab(dev->ctrl_has_crop_cap, grab);
        v4l2_ctrl_grab(dev->ctrl_has_compose_cap, grab);
        v4l2_ctrl_grab(dev->ctrl_has_scaler_cap, grab);
}

int vivid_start_generating_vid_cap(struct vivid_dev *dev, bool *pstreaming)
{
        dprintk(dev, 1, "%s\n", __func__);

        if (dev->kthread_vid_cap) {
                u32 seq_count = dev->cap_seq_count + dev->seq_wrap * 128;

                if (pstreaming == &dev->vid_cap_streaming)
                        dev->vid_cap_seq_start = seq_count;
                else if (pstreaming == &dev->vbi_cap_streaming)
                        dev->vbi_cap_seq_start = seq_count;
                else
                        dev->meta_cap_seq_start = seq_count;
                *pstreaming = true;
                return 0;
        }

        /* Resets frame counters */
        tpg_init_mv_count(&dev->tpg);

        dev->vid_cap_seq_start = dev->seq_wrap * 128;
        dev->vbi_cap_seq_start = dev->seq_wrap * 128;
        dev->meta_cap_seq_start = dev->seq_wrap * 128;

        dev->kthread_vid_cap = kthread_run(vivid_thread_vid_cap, dev,
                        "%s-vid-cap", dev->v4l2_dev.name);

        if (IS_ERR(dev->kthread_vid_cap)) {
                int err = PTR_ERR(dev->kthread_vid_cap);

                dev->kthread_vid_cap = NULL;
                v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
                return err;
        }
        *pstreaming = true;
        vivid_grab_controls(dev, true);

        dprintk(dev, 1, "returning from %s\n", __func__);
        return 0;
}

void vivid_stop_generating_vid_cap(struct vivid_dev *dev, bool *pstreaming)
{
        dprintk(dev, 1, "%s\n", __func__);

        if (dev->kthread_vid_cap == NULL)
                return;

        *pstreaming = false;
        if (pstreaming == &dev->vid_cap_streaming) {
                /* Release all active buffers */
                while (!list_empty(&dev->vid_cap_active)) {
                        struct vivid_buffer *buf;

                        buf = list_entry(dev->vid_cap_active.next,
                                         struct vivid_buffer, list);
                        list_del(&buf->list);
                        v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
                                                   &dev->ctrl_hdl_vid_cap);
                        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
                        dprintk(dev, 2, "vid_cap buffer %d done\n",
                                buf->vb.vb2_buf.index);
                }
        }

        if (pstreaming == &dev->vbi_cap_streaming) {
                while (!list_empty(&dev->vbi_cap_active)) {
                        struct vivid_buffer *buf;

                        buf = list_entry(dev->vbi_cap_active.next,
                                         struct vivid_buffer, list);
                        list_del(&buf->list);
                        v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
                                                   &dev->ctrl_hdl_vbi_cap);
                        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
                        dprintk(dev, 2, "vbi_cap buffer %d done\n",
                                buf->vb.vb2_buf.index);
                }
        }

        if (pstreaming == &dev->meta_cap_streaming) {
                while (!list_empty(&dev->meta_cap_active)) {
                        struct vivid_buffer *buf;

                        buf = list_entry(dev->meta_cap_active.next,
                                         struct vivid_buffer, list);
                        list_del(&buf->list);
                        v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
                                                   &dev->ctrl_hdl_meta_cap);
                        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
                        dprintk(dev, 2, "meta_cap buffer %d done\n",
                                buf->vb.vb2_buf.index);
                }
        }

        if (dev->vid_cap_streaming || dev->vbi_cap_streaming ||
            dev->meta_cap_streaming)
                return;

        /* shutdown control thread */
        vivid_grab_controls(dev, false);
        kthread_stop(dev->kthread_vid_cap);
        dev->kthread_vid_cap = NULL;
}