1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Linux driver for Philips webcam
3 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 & pcwx
8 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 the
11 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
pwc_decompress(struct pwc_device * pdev,struct pwc_frame_buf * fbuf)21 int 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 the
39 * first 3 bytes is filled (Nala case). We can
40 * determine this using the type of the webcam */
41 memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
42 memcpy(raw_frame+1, yuv, pdev->frame_size);
43 vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
44 pdev->frame_size + sizeof(struct pwc_raw_frame));
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 the
55 * 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 else
70 *dstu++ = *src++;
71 }
72 }
73
74 return 0;
75 }
76
77 /*
78 * Compressed;
79 * the decompressor routines will write the data in planar format
80 * 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