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1// SPDX-License-Identifier: GPL-2.0-or-later2/* Linux driver for Philips webcam3 Decompression frontend.4 (C) 1999-2003 Nemosoft Unv.5 (C) 2004-2006 Luc Saillard (luc@saillard.org)6 7 NOTE: this version of pwc is an unofficial (modified) release of pwc & pcwx8 driver and thus may have bugs that are not present in the original version.9 Please send bug reports and support requests to <luc@saillard.org>.10 The decompression routines have been implemented by reverse-engineering the11 Nemosoft binary pwcx module. Caveat emptor.12*/13 14#include <asm/current.h>15#include <asm/types.h>16 17#include "pwc.h"18#include "pwc-dec1.h"19#include "pwc-dec23.h"20 21int pwc_decompress(struct pwc_device *pdev, struct pwc_frame_buf *fbuf)22{23 int n, line, col;24 void *yuv, *image;25 u16 *src;26 u16 *dsty, *dstu, *dstv;27 28 image = vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0);29 30 yuv = fbuf->data + pdev->frame_header_size; /* Skip header */31 32 /* Raw format; that's easy... */33 if (pdev->pixfmt != V4L2_PIX_FMT_YUV420)34 {35 struct pwc_raw_frame *raw_frame = image;36 raw_frame->type = cpu_to_le16(pdev->type);37 raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);38 /* cmd_buf is always 4 bytes, but sometimes, only the39 * first 3 bytes is filled (Nala case). We can40 * determine this using the type of the webcam */41 memcpy(raw_frame->cmd, pdev->cmd_buf, 4);42 memcpy(raw_frame->rawframe, yuv, pdev->frame_size);43 vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,44 struct_size(raw_frame, rawframe, pdev->frame_size));45 return 0;46 }47 48 vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,49 pdev->width * pdev->height * 3 / 2);50 51 if (pdev->vbandlength == 0) {52 /* Uncompressed mode.53 *54 * We do some byte shuffling here to go from the55 * native format to YUV420P.56 */57 src = (u16 *)yuv;58 n = pdev->width * pdev->height;59 dsty = (u16 *)(image);60 dstu = (u16 *)(image + n);61 dstv = (u16 *)(image + n + n / 4);62 63 for (line = 0; line < pdev->height; line++) {64 for (col = 0; col < pdev->width; col += 4) {65 *dsty++ = *src++;66 *dsty++ = *src++;67 if (line & 1)68 *dstv++ = *src++;69 else70 *dstu++ = *src++;71 }72 }73 74 return 0;75 }76 77 /*78 * Compressed;79 * the decompressor routines will write the data in planar format80 * immediately.81 */82 if (DEVICE_USE_CODEC1(pdev->type)) {83 84 /* TODO & FIXME */85 PWC_ERROR("This chipset is not supported for now\n");86 return -ENXIO; /* No such device or address: missing decompressor */87 88 } else {89 pwc_dec23_decompress(pdev, yuv, image);90 }91 return 0;92}93