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 vim: set ts=8:
15 */
16
17 #include <asm/current.h>
18 #include <asm/types.h>
19
20 #include "pwc.h"
21 #include "pwc-dec1.h"
22 #include "pwc-dec23.h"
23
pwc_decompress(struct pwc_device * pdev,struct pwc_frame_buf * fbuf)24 int pwc_decompress(struct pwc_device *pdev, struct pwc_frame_buf *fbuf)
25 {
26 int n, line, col;
27 void *yuv, *image;
28 u16 *src;
29 u16 *dsty, *dstu, *dstv;
30
31 image = vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0);
32
33 yuv = fbuf->data + pdev->frame_header_size; /* Skip header */
34
35 /* Raw format; that's easy... */
36 if (pdev->pixfmt != V4L2_PIX_FMT_YUV420)
37 {
38 struct pwc_raw_frame *raw_frame = image;
39 raw_frame->type = cpu_to_le16(pdev->type);
40 raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);
41 /* cmd_buf is always 4 bytes, but sometimes, only the
42 * first 3 bytes is filled (Nala case). We can
43 * determine this using the type of the webcam */
44 memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
45 memcpy(raw_frame+1, yuv, pdev->frame_size);
46 vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
47 pdev->frame_size + sizeof(struct pwc_raw_frame));
48 return 0;
49 }
50
51 vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
52 pdev->width * pdev->height * 3 / 2);
53
54 if (pdev->vbandlength == 0) {
55 /* Uncompressed mode.
56 *
57 * We do some byte shuffling here to go from the
58 * native format to YUV420P.
59 */
60 src = (u16 *)yuv;
61 n = pdev->width * pdev->height;
62 dsty = (u16 *)(image);
63 dstu = (u16 *)(image + n);
64 dstv = (u16 *)(image + n + n / 4);
65
66 for (line = 0; line < pdev->height; line++) {
67 for (col = 0; col < pdev->width; col += 4) {
68 *dsty++ = *src++;
69 *dsty++ = *src++;
70 if (line & 1)
71 *dstv++ = *src++;
72 else
73 *dstu++ = *src++;
74 }
75 }
76
77 return 0;
78 }
79
80 /*
81 * Compressed;
82 * the decompressor routines will write the data in planar format
83 * immediately.
84 */
85 if (DEVICE_USE_CODEC1(pdev->type)) {
86
87 /* TODO & FIXME */
88 PWC_ERROR("This chipset is not supported for now\n");
89 return -ENXIO; /* No such device or address: missing decompressor */
90
91 } else {
92 pwc_dec23_decompress(pdev, yuv, image);
93 }
94 return 0;
95 }
96
