u32 frame_sequence; /* frame sequence counter */
        bool last_eof;  /* waiting for last EOF at stream off */
        bool nfb4eof;    /* NFB4EOF encountered during streaming */
+       bool interweave_swap; /* swap top/bottom lines when interweaving */
        struct completion last_eof_comp;
 };
 
        if (ipu_idmac_buffer_is_ready(ch, priv->ipu_buf_num))
                ipu_idmac_clear_buffer(ch, priv->ipu_buf_num);
 
+       if (priv->interweave_swap && ch == priv->out_ch)
+               phys += vdev->fmt.fmt.pix.bytesperline;
+
        ipu_cpmem_set_buffer(ch, priv->ipu_buf_num, phys);
 }
 
         * the IDMAC output channel.
         */
        interweave = V4L2_FIELD_IS_INTERLACED(image.pix.field) &&
-               V4L2_FIELD_IS_SEQUENTIAL(outfmt->field) &&
-               channel == priv->out_ch;
+               V4L2_FIELD_IS_SEQUENTIAL(outfmt->field);
+       priv->interweave_swap = interweave &&
+               image.pix.field == V4L2_FIELD_INTERLACED_BT;
 
        if (rot_swap_width_height) {
                swap(image.pix.width, image.pix.height);
                        (image.pix.width * outcc->bpp) >> 3;
        }
 
+       if (priv->interweave_swap && channel == priv->out_ch) {
+               /* start interweave scan at 1st top line (2nd line) */
+               image.rect.top = 1;
+       }
+
        image.phys0 = addr0;
        image.phys1 = addr1;
 
         * channels for planar 4:2:0 (but not when enabling IDMAC
         * interweaving, they are incompatible).
         */
-       if (!interweave && (channel == priv->out_ch ||
-                           channel == priv->rot_out_ch)) {
+       if ((channel == priv->out_ch && !interweave) ||
+           channel == priv->rot_out_ch) {
                switch (image.pix.pixelformat) {
                case V4L2_PIX_FMT_YUV420:
                case V4L2_PIX_FMT_YVU420:
        if (rot_mode)
                ipu_cpmem_set_rotation(channel, rot_mode);
 
-       if (interweave)
-               ipu_cpmem_interlaced_scan(channel, image.pix.bytesperline,
+       if (interweave && channel == priv->out_ch)
+               ipu_cpmem_interlaced_scan(channel,
+                                         priv->interweave_swap ?
+                                         -image.pix.bytesperline :
+                                         image.pix.bytesperline,
                                          image.pix.pixelformat);
 
        ret = ipu_ic_task_idma_init(priv->ic, channel,
 
        u32 frame_sequence; /* frame sequence counter */
        bool last_eof;   /* waiting for last EOF at stream off */
        bool nfb4eof;    /* NFB4EOF encountered during streaming */
+       bool interweave_swap; /* swap top/bottom lines when interweaving */
        struct completion last_eof_comp;
 };
 
        if (ipu_idmac_buffer_is_ready(priv->idmac_ch, priv->ipu_buf_num))
                ipu_idmac_clear_buffer(priv->idmac_ch, priv->ipu_buf_num);
 
+       if (priv->interweave_swap)
+               phys += vdev->fmt.fmt.pix.bytesperline;
+
        ipu_cpmem_set_buffer(priv->idmac_ch, priv->ipu_buf_num, phys);
 }
 
         */
        interweave = V4L2_FIELD_IS_INTERLACED(image.pix.field) &&
                V4L2_FIELD_IS_SEQUENTIAL(outfmt->field);
+       priv->interweave_swap = interweave &&
+               image.pix.field == V4L2_FIELD_INTERLACED_BT;
 
        switch (image.pix.pixelformat) {
        case V4L2_PIX_FMT_SBGGR8:
        }
 
        if (passthrough) {
+               if (priv->interweave_swap) {
+                       /* start interweave scan at 1st top line (2nd line) */
+                       image.phys0 += image.pix.bytesperline;
+                       image.phys1 += image.pix.bytesperline;
+               }
+
                ipu_cpmem_set_resolution(priv->idmac_ch,
                                         image.rect.width * passthrough_cycles,
                                         image.rect.height);
                ipu_cpmem_set_format_passthrough(priv->idmac_ch,
                                                 passthrough_bits);
        } else {
+               if (priv->interweave_swap) {
+                       /* start interweave scan at 1st top line (2nd line) */
+                       image.rect.top = 1;
+               }
+
                ret = ipu_cpmem_set_image(priv->idmac_ch, &image);
                if (ret)
                        goto unsetup_vb2;
 
        if (interweave)
                ipu_cpmem_interlaced_scan(priv->idmac_ch,
+                                         priv->interweave_swap ?
+                                         -image.pix.bytesperline :
                                          image.pix.bytesperline,
                                          image.pix.pixelformat);
 
        switch (infmt->field) {
        case V4L2_FIELD_SEQ_TB:
        case V4L2_FIELD_SEQ_BT:
+               /*
+                * If the user requests sequential at the source pad,
+                * allow it (along with possibly inverting field order).
+                * Otherwise passthrough the field type.
+                */
+               if (!V4L2_FIELD_IS_SEQUENTIAL(sdformat->format.field))
+                       sdformat->format.field = infmt->field;
+               break;
        case V4L2_FIELD_ALTERNATE:
                /*
-                * If the sink is sequential or alternating fields,
-                * allow only SEQ_TB at the source.
-                *
                 * This driver does not support alternate field mode, and
                 * the CSI captures a whole frame, so the CSI never presents
-                * alternate mode at its source pads.
+                * alternate mode at its source pads. If user has not
+                * already requested sequential, translate ALTERNATE at
+                * sink pad to SEQ_TB or SEQ_BT at the source pad depending
+                * on input height (assume NTSC BT order if 480 total active
+                * frame lines, otherwise PAL TB order).
                 */
-               sdformat->format.field = V4L2_FIELD_SEQ_TB;
+               if (!V4L2_FIELD_IS_SEQUENTIAL(sdformat->format.field))
+                       sdformat->format.field = (infmt->height == 480 / 2) ?
+                               V4L2_FIELD_SEQ_BT : V4L2_FIELD_SEQ_TB;
                break;
        default:
                /* Passthrough for all other input field types */