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
24int 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