// SPDX-License-Identifier: GPL-2.0-or-later
/*
    Vertical Blank Interval support functions
    Copyright (C) 2004-2007  Hans Verkuil <hverkuil@kernel.org>

 */

#include "ivtv-driver.h"
#include "ivtv-i2c.h"
#include "ivtv-ioctl.h"
#include "ivtv-queue.h"
#include "ivtv-cards.h"
#include "ivtv-vbi.h"

static void ivtv_set_vps(struct ivtv *itv, int enabled)
{
        struct v4l2_sliced_vbi_data data;

        if (!(itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT))
                return;
        data.id = V4L2_SLICED_VPS;
        data.field = 0;
        data.line = enabled ? 16 : 0;
        data.data[2] = itv->vbi.vps_payload.data[0];
        data.data[8] = itv->vbi.vps_payload.data[1];
        data.data[9] = itv->vbi.vps_payload.data[2];
        data.data[10] = itv->vbi.vps_payload.data[3];
        data.data[11] = itv->vbi.vps_payload.data[4];
        ivtv_call_hw(itv, IVTV_HW_SAA7127, vbi, s_vbi_data, &data);
}

static void ivtv_set_cc(struct ivtv *itv, int mode, const struct vbi_cc *cc)
{
        struct v4l2_sliced_vbi_data data;

        if (!(itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT))
                return;
        data.id = V4L2_SLICED_CAPTION_525;
        data.field = 0;
        data.line = (mode & 1) ? 21 : 0;
        data.data[0] = cc->odd[0];
        data.data[1] = cc->odd[1];
        ivtv_call_hw(itv, IVTV_HW_SAA7127, vbi, s_vbi_data, &data);
        data.field = 1;
        data.line = (mode & 2) ? 21 : 0;
        data.data[0] = cc->even[0];
        data.data[1] = cc->even[1];
        ivtv_call_hw(itv, IVTV_HW_SAA7127, vbi, s_vbi_data, &data);
}

static void ivtv_set_wss(struct ivtv *itv, int enabled, int mode)
{
        struct v4l2_sliced_vbi_data data;

        if (!(itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT))
                return;
        /* When using a 50 Hz system, always turn on the
           wide screen signal with 4x3 ratio as the default.
           Turning this signal on and off can confuse certain
           TVs. As far as I can tell there is no reason not to
           transmit this signal. */
        if ((itv->std_out & V4L2_STD_625_50) && !enabled) {
                enabled = 1;
                mode = 0x08;  /* 4x3 full format */
        }
        data.id = V4L2_SLICED_WSS_625;
        data.field = 0;
        data.line = enabled ? 23 : 0;
        data.data[0] = mode & 0xff;
        data.data[1] = (mode >> 8) & 0xff;
        ivtv_call_hw(itv, IVTV_HW_SAA7127, vbi, s_vbi_data, &data);
}

static int odd_parity(u8 c)
{
        c ^= (c >> 4);
        c ^= (c >> 2);
        c ^= (c >> 1);

        return c & 1;
}

static void ivtv_write_vbi_line(struct ivtv *itv,
                                const struct v4l2_sliced_vbi_data *d,
                                struct vbi_cc *cc, int *found_cc)
{
        struct vbi_info *vi = &itv->vbi;

        if (d->id == V4L2_SLICED_CAPTION_525 && d->line == 21) {
                if (d->field) {
                        cc->even[0] = d->data[0];
                        cc->even[1] = d->data[1];
                } else {
                        cc->odd[0] = d->data[0];
                        cc->odd[1] = d->data[1];
                }
                *found_cc = 1;
        } else if (d->id == V4L2_SLICED_VPS && d->line == 16 && d->field == 0) {
                struct vbi_vps vps;

                vps.data[0] = d->data[2];
                vps.data[1] = d->data[8];
                vps.data[2] = d->data[9];
                vps.data[3] = d->data[10];
                vps.data[4] = d->data[11];
                if (memcmp(&vps, &vi->vps_payload, sizeof(vps))) {
                        vi->vps_payload = vps;
                        set_bit(IVTV_F_I_UPDATE_VPS, &itv->i_flags);
                }
        } else if (d->id == V4L2_SLICED_WSS_625 &&
                   d->line == 23 && d->field == 0) {
                int wss = d->data[0] | d->data[1] << 8;

                if (vi->wss_payload != wss) {
                        vi->wss_payload = wss;
                        set_bit(IVTV_F_I_UPDATE_WSS, &itv->i_flags);
                }
        }
}

static void ivtv_write_vbi_cc_lines(struct ivtv *itv, const struct vbi_cc *cc)
{
        struct vbi_info *vi = &itv->vbi;

        if (vi->cc_payload_idx < ARRAY_SIZE(vi->cc_payload)) {
                memcpy(&vi->cc_payload[vi->cc_payload_idx], cc,
                       sizeof(struct vbi_cc));
                vi->cc_payload_idx++;
                set_bit(IVTV_F_I_UPDATE_CC, &itv->i_flags);
        }
}

static void ivtv_write_vbi(struct ivtv *itv,
                           const struct v4l2_sliced_vbi_data *sliced,
                           size_t cnt)
{
        struct vbi_cc cc = { .odd = { 0x80, 0x80 }, .even = { 0x80, 0x80 } };
        int found_cc = 0;
        size_t i;

        for (i = 0; i < cnt; i++)
                ivtv_write_vbi_line(itv, sliced + i, &cc, &found_cc);

        if (found_cc)
                ivtv_write_vbi_cc_lines(itv, &cc);
}

ssize_t
ivtv_write_vbi_from_user(struct ivtv *itv,
                         const struct v4l2_sliced_vbi_data __user *sliced,
                         size_t cnt)
{
        struct vbi_cc cc = { .odd = { 0x80, 0x80 }, .even = { 0x80, 0x80 } };
        int found_cc = 0;
        size_t i;
        struct v4l2_sliced_vbi_data d;
        ssize_t ret = cnt * sizeof(struct v4l2_sliced_vbi_data);

        for (i = 0; i < cnt; i++) {
                if (copy_from_user(&d, sliced + i,
                                   sizeof(struct v4l2_sliced_vbi_data))) {
                        ret = -EFAULT;
                        break;
                }
                ivtv_write_vbi_line(itv, &d, &cc, &found_cc);
        }

        if (found_cc)
                ivtv_write_vbi_cc_lines(itv, &cc);

        return ret;
}

static void copy_vbi_data(struct ivtv *itv, int lines, u32 pts_stamp)
{
        int line = 0;
        int i;
        u32 linemask[2] = { 0, 0 };
        unsigned short size;
        static const u8 mpeg_hdr_data[] = {
                0x00, 0x00, 0x01, 0xba, 0x44, 0x00, 0x0c, 0x66,
                0x24, 0x01, 0x01, 0xd1, 0xd3, 0xfa, 0xff, 0xff,
                0x00, 0x00, 0x01, 0xbd, 0x00, 0x1a, 0x84, 0x80,
                0x07, 0x21, 0x00, 0x5d, 0x63, 0xa7, 0xff, 0xff
        };
        const int sd = sizeof(mpeg_hdr_data);   /* start of vbi data */
        int idx = itv->vbi.frame % IVTV_VBI_FRAMES;
        u8 *dst = &itv->vbi.sliced_mpeg_data[idx][0];

        for (i = 0; i < lines; i++) {
                int f, l;

                if (itv->vbi.sliced_data[i].id == 0)
                        continue;

                l = itv->vbi.sliced_data[i].line - 6;
                f = itv->vbi.sliced_data[i].field;
                if (f)
                        l += 18;
                if (l < 32)
                        linemask[0] |= (1 << l);
                else
                        linemask[1] |= (1 << (l - 32));
                dst[sd + 12 + line * 43] =
                        ivtv_service2vbi(itv->vbi.sliced_data[i].id);
                memcpy(dst + sd + 12 + line * 43 + 1, itv->vbi.sliced_data[i].data, 42);
                line++;
        }
        memcpy(dst, mpeg_hdr_data, sizeof(mpeg_hdr_data));
        if (line == 36) {
                /* All lines are used, so there is no space for the linemask
                   (the max size of the VBI data is 36 * 43 + 4 bytes).
                   So in this case we use the magic number 'ITV0'. */
                memcpy(dst + sd, "ITV0", 4);
                memmove(dst + sd + 4, dst + sd + 12, line * 43);
                size = 4 + ((43 * line + 3) & ~3);
        } else {
                memcpy(dst + sd, "itv0", 4);
                cpu_to_le32s(&linemask[0]);
                cpu_to_le32s(&linemask[1]);
                memcpy(dst + sd + 4, &linemask[0], 8);
                size = 12 + ((43 * line + 3) & ~3);
        }
        dst[4+16] = (size + 10) >> 8;
        dst[5+16] = (size + 10) & 0xff;
        dst[9+16] = 0x21 | ((pts_stamp >> 29) & 0x6);
        dst[10+16] = (pts_stamp >> 22) & 0xff;
        dst[11+16] = 1 | ((pts_stamp >> 14) & 0xff);
        dst[12+16] = (pts_stamp >> 7) & 0xff;
        dst[13+16] = 1 | ((pts_stamp & 0x7f) << 1);
        itv->vbi.sliced_mpeg_size[idx] = sd + size;
}

static int ivtv_convert_ivtv_vbi(struct ivtv *itv, u8 *p)
{
        u32 linemask[2];
        int i, l, id2;
        int line = 0;

        if (!memcmp(p, "itv0", 4)) {
                memcpy(linemask, p + 4, 8);
                p += 12;
        } else if (!memcmp(p, "ITV0", 4)) {
                linemask[0] = 0xffffffff;
                linemask[1] = 0xf;
                p += 4;
        } else {
                /* unknown VBI data, convert to empty VBI frame */
                linemask[0] = linemask[1] = 0;
        }
        for (i = 0; i < 36; i++) {
                int err = 0;

                if (i < 32 && !(linemask[0] & (1 << i)))
                        continue;
                if (i >= 32 && !(linemask[1] & (1 << (i - 32))))
                        continue;
                id2 = *p & 0xf;
                switch (id2) {
                case IVTV_SLICED_TYPE_TELETEXT_B:
                        id2 = V4L2_SLICED_TELETEXT_B;
                        break;
                case IVTV_SLICED_TYPE_CAPTION_525:
                        id2 = V4L2_SLICED_CAPTION_525;
                        err = !odd_parity(p[1]) || !odd_parity(p[2]);
                        break;
                case IVTV_SLICED_TYPE_VPS:
                        id2 = V4L2_SLICED_VPS;
                        break;
                case IVTV_SLICED_TYPE_WSS_625:
                        id2 = V4L2_SLICED_WSS_625;
                        break;
                default:
                        id2 = 0;
                        break;
                }
                if (err == 0) {
                        l = (i < 18) ? i + 6 : i - 18 + 6;
                        itv->vbi.sliced_dec_data[line].line = l;
                        itv->vbi.sliced_dec_data[line].field = i >= 18;
                        itv->vbi.sliced_dec_data[line].id = id2;
                        memcpy(itv->vbi.sliced_dec_data[line].data, p + 1, 42);
                        line++;
                }
                p += 43;
        }
        while (line < 36) {
                itv->vbi.sliced_dec_data[line].id = 0;
                itv->vbi.sliced_dec_data[line].line = 0;
                itv->vbi.sliced_dec_data[line].field = 0;
                line++;
        }
        return line * sizeof(itv->vbi.sliced_dec_data[0]);
}

/* Compress raw VBI format, removes leading SAV codes and surplus space after the
   field.
   Returns new compressed size. */
static u32 compress_raw_buf(struct ivtv *itv, u8 *buf, u32 size)
{
        u32 line_size = itv->vbi.raw_decoder_line_size;
        u32 lines = itv->vbi.count;
        u8 sav1 = itv->vbi.raw_decoder_sav_odd_field;
        u8 sav2 = itv->vbi.raw_decoder_sav_even_field;
        u8 *q = buf;
        u8 *p;
        int i;

        for (i = 0; i < lines; i++) {
                p = buf + i * line_size;

                /* Look for SAV code */
                if (p[0] != 0xff || p[1] || p[2] || (p[3] != sav1 && p[3] != sav2)) {
                        break;
                }
                memcpy(q, p + 4, line_size - 4);
                q += line_size - 4;
        }
        return lines * (line_size - 4);
}


/* Compressed VBI format, all found sliced blocks put next to one another
   Returns new compressed size */
static u32 compress_sliced_buf(struct ivtv *itv, u32 line, u8 *buf, u32 size, u8 sav)
{
        u32 line_size = itv->vbi.sliced_decoder_line_size;
        struct v4l2_decode_vbi_line vbi = {};
        int i;
        unsigned lines = 0;

        /* find the first valid line */
        for (i = 0; i < size; i++, buf++) {
                if (buf[0] == 0xff && !buf[1] && !buf[2] && buf[3] == sav)
                        break;
        }

        size -= i;
        if (size < line_size) {
                return line;
        }
        for (i = 0; i < size / line_size; i++) {
                u8 *p = buf + i * line_size;

                /* Look for SAV code  */
                if (p[0] != 0xff || p[1] || p[2] || p[3] != sav) {
                        continue;
                }
                vbi.p = p + 4;
                v4l2_subdev_call(itv->sd_video, vbi, decode_vbi_line, &vbi);
                if (vbi.type && !(lines & (1 << vbi.line))) {
                        lines |= 1 << vbi.line;
                        itv->vbi.sliced_data[line].id = vbi.type;
                        itv->vbi.sliced_data[line].field = vbi.is_second_field;
                        itv->vbi.sliced_data[line].line = vbi.line;
                        memcpy(itv->vbi.sliced_data[line].data, vbi.p, 42);
                        line++;
                }
        }
        return line;
}

void ivtv_process_vbi_data(struct ivtv *itv, struct ivtv_buffer *buf,
                           u64 pts_stamp, int streamtype)
{
        u8 *p = (u8 *) buf->buf;
        u32 size = buf->bytesused;
        int y;

        /* Raw VBI data */
        if (streamtype == IVTV_ENC_STREAM_TYPE_VBI && ivtv_raw_vbi(itv)) {
                u8 type;

                ivtv_buf_swap(buf);

                type = p[3];

                size = buf->bytesused = compress_raw_buf(itv, p, size);

                /* second field of the frame? */
                if (type == itv->vbi.raw_decoder_sav_even_field) {
                        /* Dirty hack needed for backwards
                           compatibility of old VBI software. */
                        p += size - 4;
                        memcpy(p, &itv->vbi.frame, 4);
                        itv->vbi.frame++;
                }
                return;
        }

        /* Sliced VBI data with data insertion */
        if (streamtype == IVTV_ENC_STREAM_TYPE_VBI) {
                int lines;

                ivtv_buf_swap(buf);

                /* first field */
                lines = compress_sliced_buf(itv, 0, p, size / 2,
                        itv->vbi.sliced_decoder_sav_odd_field);
                /* second field */
                /* experimentation shows that the second half does not always begin
                   at the exact address. So start a bit earlier (hence 32). */
                lines = compress_sliced_buf(itv, lines, p + size / 2 - 32, size / 2 + 32,
                        itv->vbi.sliced_decoder_sav_even_field);
                /* always return at least one empty line */
                if (lines == 0) {
                        itv->vbi.sliced_data[0].id = 0;
                        itv->vbi.sliced_data[0].line = 0;
                        itv->vbi.sliced_data[0].field = 0;
                        lines = 1;
                }
                buf->bytesused = size = lines * sizeof(itv->vbi.sliced_data[0]);
                memcpy(p, &itv->vbi.sliced_data[0], size);

                if (itv->vbi.insert_mpeg) {
                        copy_vbi_data(itv, lines, pts_stamp);
                }
                itv->vbi.frame++;
                return;
        }

        /* Sliced VBI re-inserted from an MPEG stream */
        if (streamtype == IVTV_DEC_STREAM_TYPE_VBI) {
                /* If the size is not 4-byte aligned, then the starting address
                   for the swapping is also shifted. After swapping the data the
                   real start address of the VBI data is exactly 4 bytes after the
                   original start. It's a bit fiddly but it works like a charm.
                   Non-4-byte alignment happens when an lseek is done on the input
                   mpeg file to a non-4-byte aligned position. So on arrival here
                   the VBI data is also non-4-byte aligned. */
                int offset = size & 3;
                int cnt;

                if (offset) {
                        p += 4 - offset;
                }
                /* Swap Buffer */
                for (y = 0; y < size; y += 4) {
                       swab32s((u32 *)(p + y));
                }

                cnt = ivtv_convert_ivtv_vbi(itv, p + offset);
                memcpy(buf->buf, itv->vbi.sliced_dec_data, cnt);
                buf->bytesused = cnt;

                ivtv_write_vbi(itv, itv->vbi.sliced_dec_data,
                               cnt / sizeof(itv->vbi.sliced_dec_data[0]));
                return;
        }
}

void ivtv_disable_cc(struct ivtv *itv)
{
        struct vbi_cc cc = { .odd = { 0x80, 0x80 }, .even = { 0x80, 0x80 } };

        clear_bit(IVTV_F_I_UPDATE_CC, &itv->i_flags);
        ivtv_set_cc(itv, 0, &cc);
        itv->vbi.cc_payload_idx = 0;
}


void ivtv_vbi_work_handler(struct ivtv *itv)
{
        struct vbi_info *vi = &itv->vbi;
        struct v4l2_sliced_vbi_data data;
        struct vbi_cc cc = { .odd = { 0x80, 0x80 }, .even = { 0x80, 0x80 } };

        /* Lock */
        if (itv->output_mode == OUT_PASSTHROUGH) {
                if (itv->is_50hz) {
                        data.id = V4L2_SLICED_WSS_625;
                        data.field = 0;

                        if (v4l2_subdev_call(itv->sd_video, vbi, g_vbi_data, &data) == 0) {
                                ivtv_set_wss(itv, 1, data.data[0] & 0xf);
                                vi->wss_missing_cnt = 0;
                        } else if (vi->wss_missing_cnt == 4) {
                                ivtv_set_wss(itv, 1, 0x8);  /* 4x3 full format */
                        } else {
                                vi->wss_missing_cnt++;
                        }
                }
                else {
                        int mode = 0;

                        data.id = V4L2_SLICED_CAPTION_525;
                        data.field = 0;
                        if (v4l2_subdev_call(itv->sd_video, vbi, g_vbi_data, &data) == 0) {
                                mode |= 1;
                                cc.odd[0] = data.data[0];
                                cc.odd[1] = data.data[1];
                        }
                        data.field = 1;
                        if (v4l2_subdev_call(itv->sd_video, vbi, g_vbi_data, &data) == 0) {
                                mode |= 2;
                                cc.even[0] = data.data[0];
                                cc.even[1] = data.data[1];
                        }
                        if (mode) {
                                vi->cc_missing_cnt = 0;
                                ivtv_set_cc(itv, mode, &cc);
                        } else if (vi->cc_missing_cnt == 4) {
                                ivtv_set_cc(itv, 0, &cc);
                        } else {
                                vi->cc_missing_cnt++;
                        }
                }
                return;
        }

        if (test_and_clear_bit(IVTV_F_I_UPDATE_WSS, &itv->i_flags)) {
                ivtv_set_wss(itv, 1, vi->wss_payload & 0xf);
        }

        if (test_bit(IVTV_F_I_UPDATE_CC, &itv->i_flags)) {
                if (vi->cc_payload_idx == 0) {
                        clear_bit(IVTV_F_I_UPDATE_CC, &itv->i_flags);
                        ivtv_set_cc(itv, 3, &cc);
                }
                while (vi->cc_payload_idx) {
                        cc = vi->cc_payload[0];

                        memmove(vi->cc_payload, vi->cc_payload + 1,
                                        sizeof(vi->cc_payload) - sizeof(vi->cc_payload[0]));
                        vi->cc_payload_idx--;
                        if (vi->cc_payload_idx && cc.odd[0] == 0x80 && cc.odd[1] == 0x80)
                                continue;

                        ivtv_set_cc(itv, 3, &cc);
                        break;
                }
        }

        if (test_and_clear_bit(IVTV_F_I_UPDATE_VPS, &itv->i_flags)) {
                ivtv_set_vps(itv, 1);
        }
}