1 /* Linux driver for Philips webcam
2    Decompression frontend.
3    (C) 1999-2003 Nemosoft Unv.
4    (C) 2004-2006 Luc Saillard (luc@saillard.org)
5 
6    NOTE: this version of pwc is an unofficial (modified) release of pwc & pcwx
7    driver and thus may have bugs that are not present in the original version.
8    Please send bug reports and support requests to <luc@saillard.org>.
9    The decompression routines have been implemented by reverse-engineering the
10    Nemosoft binary pwcx module. Caveat emptor.
11 
12    This program is free software; you can redistribute it and/or modify
13    it under the terms of the GNU General Public License as published by
14    the Free Software Foundation; either version 2 of the License, or
15    (at your option) any later version.
16 
17    This program is distributed in the hope that it will be useful,
18    but WITHOUT ANY WARRANTY; without even the implied warranty of
19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20    GNU General Public License for more details.
21 
22    You should have received a copy of the GNU General Public License
23    along with this program; if not, write to the Free Software
24    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
25 
26    vim: set ts=8:
27 */
28 
29 #include <asm/current.h>
30 #include <asm/types.h>
31 
32 #include "pwc.h"
33 #include "pwc-dec1.h"
34 #include "pwc-dec23.h"
35 
36 int pwc_decompress(struct pwc_device *pdev, struct pwc_frame_buf *fbuf)
37 {
38 	int n, line, col;
39 	void *yuv, *image;
40 	u16 *src;
41 	u16 *dsty, *dstu, *dstv;
42 
43 	image = vb2_plane_vaddr(&fbuf->vb, 0);
44 
45 	yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */
46 
47 	/* Raw format; that's easy... */
48 	if (pdev->pixfmt != V4L2_PIX_FMT_YUV420)
49 	{
50 		struct pwc_raw_frame *raw_frame = image;
51 		raw_frame->type = cpu_to_le16(pdev->type);
52 		raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);
53 			/* cmd_buf is always 4 bytes, but sometimes, only the
54 			 * first 3 bytes is filled (Nala case). We can
55 			 * determine this using the type of the webcam */
56 		memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
57 		memcpy(raw_frame+1, yuv, pdev->frame_size);
58 		vb2_set_plane_payload(&fbuf->vb, 0,
59 			pdev->frame_size + sizeof(struct pwc_raw_frame));
60 		return 0;
61 	}
62 
63 	vb2_set_plane_payload(&fbuf->vb, 0,
64 			      pdev->width * pdev->height * 3 / 2);
65 
66 	if (pdev->vbandlength == 0) {
67 		/* Uncompressed mode.
68 		 *
69 		 * We do some byte shuffling here to go from the
70 		 * native format to YUV420P.
71 		 */
72 		src = (u16 *)yuv;
73 		n = pdev->width * pdev->height;
74 		dsty = (u16 *)(image);
75 		dstu = (u16 *)(image + n);
76 		dstv = (u16 *)(image + n + n / 4);
77 
78 		for (line = 0; line < pdev->height; line++) {
79 			for (col = 0; col < pdev->width; col += 4) {
80 				*dsty++ = *src++;
81 				*dsty++ = *src++;
82 				if (line & 1)
83 					*dstv++ = *src++;
84 				else
85 					*dstu++ = *src++;
86 			}
87 		}
88 
89 		return 0;
90 	}
91 
92 	/*
93 	 * Compressed;
94 	 * the decompressor routines will write the data in planar format
95 	 * immediately.
96 	 */
97 	if (DEVICE_USE_CODEC1(pdev->type)) {
98 
99 		/* TODO & FIXME */
100 		PWC_ERROR("This chipset is not supported for now\n");
101 		return -ENXIO; /* No such device or address: missing decompressor */
102 
103 	} else {
104 		pwc_dec23_decompress(pdev, yuv, image);
105 	}
106 	return 0;
107 }
108