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
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 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->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 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