// SPDX-License-Identifier: GPL-2.0-or-later
/* Linux driver for Philips webcam
   Decompression frontend.
   (C) 1999-2003 Nemosoft Unv.
   (C) 2004-2006 Luc Saillard (luc@saillard.org)

   NOTE: this version of pwc is an unofficial (modified) release of pwc & pcwx
   driver and thus may have bugs that are not present in the original version.
   Please send bug reports and support requests to <luc@saillard.org>.
   The decompression routines have been implemented by reverse-engineering the
   Nemosoft binary pwcx module. Caveat emptor.
*/

#include <asm/current.h>
#include <asm/types.h>

#include "pwc.h"
#include "pwc-dec1.h"
#include "pwc-dec23.h"

int pwc_decompress(struct pwc_device *pdev, struct pwc_frame_buf *fbuf)
{
        int n, line, col;
        void *yuv, *image;
        u16 *src;
        u16 *dsty, *dstu, *dstv;

        image = vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0);

        yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */

        /* Raw format; that's easy... */
        if (pdev->pixfmt != V4L2_PIX_FMT_YUV420)
        {
                struct pwc_raw_frame *raw_frame = image;
                raw_frame->type = cpu_to_le16(pdev->type);
                raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);
                        /* cmd_buf is always 4 bytes, but sometimes, only the
                         * first 3 bytes is filled (Nala case). We can
                         * determine this using the type of the webcam */
                memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
                memcpy(raw_frame->rawframe, yuv, pdev->frame_size);
                vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
                        struct_size(raw_frame, rawframe, pdev->frame_size));
                return 0;
        }

        vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
                              pdev->width * pdev->height * 3 / 2);

        if (pdev->vbandlength == 0) {
                /* Uncompressed mode.
                 *
                 * We do some byte shuffling here to go from the
                 * native format to YUV420P.
                 */
                src = (u16 *)yuv;
                n = pdev->width * pdev->height;
                dsty = (u16 *)(image);
                dstu = (u16 *)(image + n);
                dstv = (u16 *)(image + n + n / 4);

                for (line = 0; line < pdev->height; line++) {
                        for (col = 0; col < pdev->width; col += 4) {
                                *dsty++ = *src++;
                                *dsty++ = *src++;
                                if (line & 1)
                                        *dstv++ = *src++;
                                else
                                        *dstu++ = *src++;
                        }
                }

                return 0;
        }

        /*
         * Compressed;
         * the decompressor routines will write the data in planar format
         * immediately.
         */
        if (DEVICE_USE_CODEC1(pdev->type)) {

                /* TODO & FIXME */
                PWC_ERROR("This chipset is not supported for now\n");
                return -ENXIO; /* No such device or address: missing decompressor */

        } else {
                pwc_dec23_decompress(pdev, yuv, image);
        }
        return 0;
}