diff options
Diffstat (limited to 'Documentation/usb/w9968cf.txt')
-rw-r--r-- | Documentation/usb/w9968cf.txt | 481 |
1 files changed, 481 insertions, 0 deletions
diff --git a/Documentation/usb/w9968cf.txt b/Documentation/usb/w9968cf.txt new file mode 100644 index 000000000000..18a47738d56c --- /dev/null +++ b/Documentation/usb/w9968cf.txt | |||
@@ -0,0 +1,481 @@ | |||
1 | |||
2 | W996[87]CF JPEG USB Dual Mode Camera Chip | ||
3 | Driver for Linux 2.6 (basic version) | ||
4 | ========================================= | ||
5 | |||
6 | - Documentation - | ||
7 | |||
8 | |||
9 | Index | ||
10 | ===== | ||
11 | 1. Copyright | ||
12 | 2. Disclaimer | ||
13 | 3. License | ||
14 | 4. Overview | ||
15 | 5. Supported devices | ||
16 | 6. Module dependencies | ||
17 | 7. Module loading | ||
18 | 8. Module paramaters | ||
19 | 9. Contact information | ||
20 | 10. Credits | ||
21 | |||
22 | |||
23 | 1. Copyright | ||
24 | ============ | ||
25 | Copyright (C) 2002-2004 by Luca Risolia <luca.risolia@studio.unibo.it> | ||
26 | |||
27 | |||
28 | 2. Disclaimer | ||
29 | ============= | ||
30 | Winbond is a trademark of Winbond Electronics Corporation. | ||
31 | This software is not sponsored or developed by Winbond. | ||
32 | |||
33 | |||
34 | 3. License | ||
35 | ========== | ||
36 | This program is free software; you can redistribute it and/or modify | ||
37 | it under the terms of the GNU General Public License as published by | ||
38 | the Free Software Foundation; either version 2 of the License, or | ||
39 | (at your option) any later version. | ||
40 | |||
41 | This program is distributed in the hope that it will be useful, | ||
42 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
43 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
44 | GNU General Public License for more details. | ||
45 | |||
46 | You should have received a copy of the GNU General Public License | ||
47 | along with this program; if not, write to the Free Software | ||
48 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
49 | |||
50 | |||
51 | 4. Overview | ||
52 | =========== | ||
53 | This driver supports the video streaming capabilities of the devices mounting | ||
54 | Winbond W9967CF and Winbond W9968CF JPEG USB Dual Mode Camera Chips. OV681 | ||
55 | based cameras should be supported as well. | ||
56 | |||
57 | The driver is divided into two modules: the basic one, "w9968cf", is needed for | ||
58 | the supported devices to work; the second one, "w9968cf-vpp", is an optional | ||
59 | module, which provides some useful video post-processing functions like video | ||
60 | decoding, up-scaling and colour conversions. Once the driver is installed, | ||
61 | every time an application tries to open a recognized device, "w9968cf" checks | ||
62 | the presence of the "w9968cf-vpp" module and loads it automatically by default. | ||
63 | |||
64 | Please keep in mind that official kernels do not include the second module for | ||
65 | performance purposes. However it is always recommended to download and install | ||
66 | the latest and complete release of the driver, replacing the existing one, if | ||
67 | present: it will be still even possible not to load the "w9968cf-vpp" module at | ||
68 | all, if you ever want to. Another important missing feature of the version in | ||
69 | the official Linux 2.4 kernels is the writeable /proc filesystem interface. | ||
70 | |||
71 | The latest and full-featured version of the W996[87]CF driver can be found at: | ||
72 | http://www.linux-projects.org. Please refer to the documentation included in | ||
73 | that package, if you are going to use it. | ||
74 | |||
75 | Up to 32 cameras can be handled at the same time. They can be connected and | ||
76 | disconnected from the host many times without turning off the computer, if | ||
77 | your system supports the hotplug facility. | ||
78 | |||
79 | To change the default settings for each camera, many parameters can be passed | ||
80 | through command line when the module is loaded into memory. | ||
81 | |||
82 | The driver relies on the Video4Linux, USB and I2C core modules. It has been | ||
83 | designed to run properly on SMP systems as well. An additional module, | ||
84 | "ovcamchip", is mandatory; it provides support for some OmniVision image | ||
85 | sensors connected to the W996[87]CF chips; if found in the system, the module | ||
86 | will be automatically loaded by default (provided that the kernel has been | ||
87 | compiled with the automatic module loading option). | ||
88 | |||
89 | |||
90 | 5. Supported devices | ||
91 | ==================== | ||
92 | At the moment, known W996[87]CF and OV681 based devices are: | ||
93 | - Aroma Digi Pen VGA Dual Mode ADG-5000 (unknown image sensor) | ||
94 | - AVerMedia AVerTV USB (SAA7111A, Philips FI1216Mk2 tuner, PT2313L audio chip) | ||
95 | - Creative Labs Video Blaster WebCam Go (OmniVision OV7610 sensor) | ||
96 | - Creative Labs Video Blaster WebCam Go Plus (OmniVision OV7620 sensor) | ||
97 | - Lebon LDC-035A (unknown image sensor) | ||
98 | - Ezonics EZ-802 EZMega Cam (OmniVision OV8610C sensor) | ||
99 | - OmniVision OV8610-EDE (OmniVision OV8610 sensor) | ||
100 | - OPCOM Digi Pen VGA Dual Mode Pen Camera (unknown image sensor) | ||
101 | - Pretec Digi Pen-II (OmniVision OV7620 sensor) | ||
102 | - Pretec DigiPen-480 (OmniVision OV8610 sensor) | ||
103 | |||
104 | If you know any other W996[87]CF or OV681 based cameras, please contact me. | ||
105 | |||
106 | The list above does not imply that all those devices work with this driver: up | ||
107 | until now only webcams that have an image sensor supported by the "ovcamchip" | ||
108 | module work. Kernel messages will always tell you whether this is case. | ||
109 | |||
110 | Possible external microcontrollers of those webcams are not supported: this | ||
111 | means that still images cannot be downloaded from the device memory. | ||
112 | |||
113 | Furthermore, it's worth to note that I was only able to run tests on my | ||
114 | "Creative Labs Video Blaster WebCam Go". Donations of other models, for | ||
115 | additional testing and full support, would be much appreciated. | ||
116 | |||
117 | |||
118 | 6. Module dependencies | ||
119 | ====================== | ||
120 | For it to work properly, the driver needs kernel support for Video4Linux, USB | ||
121 | and I2C, and the "ovcamchip" module for the image sensor. Make sure you are not | ||
122 | actually using any external "ovcamchip" module, given that the W996[87]CF | ||
123 | driver depends on the version of the module present in the official kernels. | ||
124 | |||
125 | The following options of the kernel configuration file must be enabled and | ||
126 | corresponding modules must be compiled: | ||
127 | |||
128 | # Multimedia devices | ||
129 | # | ||
130 | CONFIG_VIDEO_DEV=m | ||
131 | |||
132 | # I2C support | ||
133 | # | ||
134 | CONFIG_I2C=m | ||
135 | |||
136 | The I2C core module can be compiled statically in the kernel as well. | ||
137 | |||
138 | # OmniVision Camera Chip support | ||
139 | # | ||
140 | CONFIG_VIDEO_OVCAMCHIP=m | ||
141 | |||
142 | # USB support | ||
143 | # | ||
144 | CONFIG_USB=m | ||
145 | |||
146 | In addition, depending on the hardware being used, only one of the modules | ||
147 | below is necessary: | ||
148 | |||
149 | # USB Host Controller Drivers | ||
150 | # | ||
151 | CONFIG_USB_EHCI_HCD=m | ||
152 | CONFIG_USB_UHCI_HCD=m | ||
153 | CONFIG_USB_OHCI_HCD=m | ||
154 | |||
155 | And finally: | ||
156 | |||
157 | # USB Multimedia devices | ||
158 | # | ||
159 | CONFIG_USB_W9968CF=m | ||
160 | |||
161 | |||
162 | 7. Module loading | ||
163 | ================= | ||
164 | To use the driver, it is necessary to load the "w9968cf" module into memory | ||
165 | after every other module required. | ||
166 | |||
167 | Loading can be done this way, from root: | ||
168 | |||
169 | [root@localhost home]# modprobe usbcore | ||
170 | [root@localhost home]# modprobe i2c-core | ||
171 | [root@localhost home]# modprobe videodev | ||
172 | [root@localhost home]# modprobe w9968cf | ||
173 | |||
174 | At this point the pertinent devices should be recognized: "dmesg" can be used | ||
175 | to analyze kernel messages: | ||
176 | |||
177 | [user@localhost home]$ dmesg | ||
178 | |||
179 | There are a lot of parameters the module can use to change the default | ||
180 | settings for each device. To list every possible parameter with a brief | ||
181 | explanation about them and which syntax to use, it is recommended to run the | ||
182 | "modinfo" command: | ||
183 | |||
184 | [root@locahost home]# modinfo w9968cf | ||
185 | |||
186 | |||
187 | 8. Module parameters | ||
188 | ==================== | ||
189 | Module parameters are listed below: | ||
190 | ------------------------------------------------------------------------------- | ||
191 | Name: ovmod_load | ||
192 | Type: bool | ||
193 | Syntax: <0|1> | ||
194 | Description: Automatic 'ovcamchip' module loading: 0 disabled, 1 enabled. | ||
195 | If enabled, 'insmod' searches for the required 'ovcamchip' | ||
196 | module in the system, according to its configuration, and | ||
197 | loads that module automatically. This action is performed as | ||
198 | once soon as the 'w9968cf' module is loaded into memory. | ||
199 | Default: 1 | ||
200 | Note: The kernel must be compiled with the CONFIG_KMOD option | ||
201 | enabled for the 'ovcamchip' module to be loaded and for | ||
202 | this parameter to be present. | ||
203 | ------------------------------------------------------------------------------- | ||
204 | Name: vppmod_load | ||
205 | Type: bool | ||
206 | Syntax: <0|1> | ||
207 | Description: Automatic 'w9968cf-vpp' module loading: 0 disabled, 1 enabled. | ||
208 | If enabled, every time an application attempts to open a | ||
209 | camera, 'insmod' searches for the video post-processing module | ||
210 | in the system and loads it automatically (if present). | ||
211 | The optional 'w9968cf-vpp' module adds extra image manipulation | ||
212 | capabilities to the 'w9968cf' module,like software up-scaling, | ||
213 | colour conversions and video decompression for very high frame | ||
214 | rates. | ||
215 | Default: 1 | ||
216 | Note: The kernel must be compiled with the CONFIG_KMOD option | ||
217 | enabled for the 'w9968cf-vpp' module to be loaded and for | ||
218 | this parameter to be present. | ||
219 | ------------------------------------------------------------------------------- | ||
220 | Name: simcams | ||
221 | Type: int | ||
222 | Syntax: <n> | ||
223 | Description: Number of cameras allowed to stream simultaneously. | ||
224 | n may vary from 0 to 32. | ||
225 | Default: 32 | ||
226 | ------------------------------------------------------------------------------- | ||
227 | Name: video_nr | ||
228 | Type: int array (min = 0, max = 32) | ||
229 | Syntax: <-1|n[,...]> | ||
230 | Description: Specify V4L minor mode number. | ||
231 | -1 = use next available | ||
232 | n = use minor number n | ||
233 | You can specify up to 32 cameras this way. | ||
234 | For example: | ||
235 | video_nr=-1,2,-1 would assign minor number 2 to the second | ||
236 | recognized camera and use auto for the first one and for every | ||
237 | other camera. | ||
238 | Default: -1 | ||
239 | ------------------------------------------------------------------------------- | ||
240 | Name: packet_size | ||
241 | Type: int array (min = 0, max = 32) | ||
242 | Syntax: <n[,...]> | ||
243 | Description: Specify the maximum data payload size in bytes for alternate | ||
244 | settings, for each device. n is scaled between 63 and 1023. | ||
245 | Default: 1023 | ||
246 | ------------------------------------------------------------------------------- | ||
247 | Name: max_buffers | ||
248 | Type: int array (min = 0, max = 32) | ||
249 | Syntax: <n[,...]> | ||
250 | Description: For advanced users. | ||
251 | Specify the maximum number of video frame buffers to allocate | ||
252 | for each device, from 2 to 32. | ||
253 | Default: 2 | ||
254 | ------------------------------------------------------------------------------- | ||
255 | Name: double_buffer | ||
256 | Type: bool array (min = 0, max = 32) | ||
257 | Syntax: <0|1[,...]> | ||
258 | Description: Hardware double buffering: 0 disabled, 1 enabled. | ||
259 | It should be enabled if you want smooth video output: if you | ||
260 | obtain out of sync. video, disable it, or try to | ||
261 | decrease the 'clockdiv' module parameter value. | ||
262 | Default: 1 for every device. | ||
263 | ------------------------------------------------------------------------------- | ||
264 | Name: clamping | ||
265 | Type: bool array (min = 0, max = 32) | ||
266 | Syntax: <0|1[,...]> | ||
267 | Description: Video data clamping: 0 disabled, 1 enabled. | ||
268 | Default: 0 for every device. | ||
269 | ------------------------------------------------------------------------------- | ||
270 | Name: filter_type | ||
271 | Type: int array (min = 0, max = 32) | ||
272 | Syntax: <0|1|2[,...]> | ||
273 | Description: Video filter type. | ||
274 | 0 none, 1 (1-2-1) 3-tap filter, 2 (2-3-6-3-2) 5-tap filter. | ||
275 | The filter is used to reduce noise and aliasing artifacts | ||
276 | produced by the CCD or CMOS image sensor. | ||
277 | Default: 0 for every device. | ||
278 | ------------------------------------------------------------------------------- | ||
279 | Name: largeview | ||
280 | Type: bool array (min = 0, max = 32) | ||
281 | Syntax: <0|1[,...]> | ||
282 | Description: Large view: 0 disabled, 1 enabled. | ||
283 | Default: 1 for every device. | ||
284 | ------------------------------------------------------------------------------- | ||
285 | Name: upscaling | ||
286 | Type: bool array (min = 0, max = 32) | ||
287 | Syntax: <0|1[,...]> | ||
288 | Description: Software scaling (for non-compressed video only): | ||
289 | 0 disabled, 1 enabled. | ||
290 | Disable it if you have a slow CPU or you don't have enough | ||
291 | memory. | ||
292 | Default: 0 for every device. | ||
293 | Note: If 'w9968cf-vpp' is not present, this parameter is set to 0. | ||
294 | ------------------------------------------------------------------------------- | ||
295 | Name: decompression | ||
296 | Type: int array (min = 0, max = 32) | ||
297 | Syntax: <0|1|2[,...]> | ||
298 | Description: Software video decompression: | ||
299 | 0 = disables decompression | ||
300 | (doesn't allow formats needing decompression). | ||
301 | 1 = forces decompression | ||
302 | (allows formats needing decompression only). | ||
303 | 2 = allows any permitted formats. | ||
304 | Formats supporting (de)compressed video are YUV422P and | ||
305 | YUV420P/YUV420 in any resolutions where width and height are | ||
306 | multiples of 16. | ||
307 | Default: 2 for every device. | ||
308 | Note: If 'w9968cf-vpp' is not present, forcing decompression is not | ||
309 | allowed; in this case this parameter is set to 2. | ||
310 | ------------------------------------------------------------------------------- | ||
311 | Name: force_palette | ||
312 | Type: int array (min = 0, max = 32) | ||
313 | Syntax: <0|9|10|13|15|8|7|1|6|3|4|5[,...]> | ||
314 | Description: Force picture palette. | ||
315 | In order: | ||
316 | 0 = Off - allows any of the following formats: | ||
317 | 9 = UYVY 16 bpp - Original video, compression disabled | ||
318 | 10 = YUV420 12 bpp - Original video, compression enabled | ||
319 | 13 = YUV422P 16 bpp - Original video, compression enabled | ||
320 | 15 = YUV420P 12 bpp - Original video, compression enabled | ||
321 | 8 = YUVY 16 bpp - Software conversion from UYVY | ||
322 | 7 = YUV422 16 bpp - Software conversion from UYVY | ||
323 | 1 = GREY 8 bpp - Software conversion from UYVY | ||
324 | 6 = RGB555 16 bpp - Software conversion from UYVY | ||
325 | 3 = RGB565 16 bpp - Software conversion from UYVY | ||
326 | 4 = RGB24 24 bpp - Software conversion from UYVY | ||
327 | 5 = RGB32 32 bpp - Software conversion from UYVY | ||
328 | When not 0, this parameter will override 'decompression'. | ||
329 | Default: 0 for every device. Initial palette is 9 (UYVY). | ||
330 | Note: If 'w9968cf-vpp' is not present, this parameter is set to 9. | ||
331 | ------------------------------------------------------------------------------- | ||
332 | Name: force_rgb | ||
333 | Type: bool array (min = 0, max = 32) | ||
334 | Syntax: <0|1[,...]> | ||
335 | Description: Read RGB video data instead of BGR: | ||
336 | 1 = use RGB component ordering. | ||
337 | 0 = use BGR component ordering. | ||
338 | This parameter has effect when using RGBX palettes only. | ||
339 | Default: 0 for every device. | ||
340 | ------------------------------------------------------------------------------- | ||
341 | Name: autobright | ||
342 | Type: bool array (min = 0, max = 32) | ||
343 | Syntax: <0|1[,...]> | ||
344 | Description: Image sensor automatically changes brightness: | ||
345 | 0 = no, 1 = yes | ||
346 | Default: 0 for every device. | ||
347 | ------------------------------------------------------------------------------- | ||
348 | Name: autoexp | ||
349 | Type: bool array (min = 0, max = 32) | ||
350 | Syntax: <0|1[,...]> | ||
351 | Description: Image sensor automatically changes exposure: | ||
352 | 0 = no, 1 = yes | ||
353 | Default: 1 for every device. | ||
354 | ------------------------------------------------------------------------------- | ||
355 | Name: lightfreq | ||
356 | Type: int array (min = 0, max = 32) | ||
357 | Syntax: <50|60[,...]> | ||
358 | Description: Light frequency in Hz: | ||
359 | 50 for European and Asian lighting, 60 for American lighting. | ||
360 | Default: 50 for every device. | ||
361 | ------------------------------------------------------------------------------- | ||
362 | Name: bandingfilter | ||
363 | Type: bool array (min = 0, max = 32) | ||
364 | Syntax: <0|1[,...]> | ||
365 | Description: Banding filter to reduce effects of fluorescent | ||
366 | lighting: | ||
367 | 0 disabled, 1 enabled. | ||
368 | This filter tries to reduce the pattern of horizontal | ||
369 | light/dark bands caused by some (usually fluorescent) lighting. | ||
370 | Default: 0 for every device. | ||
371 | ------------------------------------------------------------------------------- | ||
372 | Name: clockdiv | ||
373 | Type: int array (min = 0, max = 32) | ||
374 | Syntax: <-1|n[,...]> | ||
375 | Description: Force pixel clock divisor to a specific value (for experts): | ||
376 | n may vary from 0 to 127. | ||
377 | -1 for automatic value. | ||
378 | See also the 'double_buffer' module parameter. | ||
379 | Default: -1 for every device. | ||
380 | ------------------------------------------------------------------------------- | ||
381 | Name: backlight | ||
382 | Type: bool array (min = 0, max = 32) | ||
383 | Syntax: <0|1[,...]> | ||
384 | Description: Objects are lit from behind: | ||
385 | 0 = no, 1 = yes | ||
386 | Default: 0 for every device. | ||
387 | ------------------------------------------------------------------------------- | ||
388 | Name: mirror | ||
389 | Type: bool array (min = 0, max = 32) | ||
390 | Syntax: <0|1[,...]> | ||
391 | Description: Reverse image horizontally: | ||
392 | 0 = no, 1 = yes | ||
393 | Default: 0 for every device. | ||
394 | ------------------------------------------------------------------------------- | ||
395 | Name: monochrome | ||
396 | Type: bool array (min = 0, max = 32) | ||
397 | Syntax: <0|1[,...]> | ||
398 | Description: The image sensor is monochrome: | ||
399 | 0 = no, 1 = yes | ||
400 | Default: 0 for every device. | ||
401 | ------------------------------------------------------------------------------- | ||
402 | Name: brightness | ||
403 | Type: long array (min = 0, max = 32) | ||
404 | Syntax: <n[,...]> | ||
405 | Description: Set picture brightness (0-65535). | ||
406 | This parameter has no effect if 'autobright' is enabled. | ||
407 | Default: 31000 for every device. | ||
408 | ------------------------------------------------------------------------------- | ||
409 | Name: hue | ||
410 | Type: long array (min = 0, max = 32) | ||
411 | Syntax: <n[,...]> | ||
412 | Description: Set picture hue (0-65535). | ||
413 | Default: 32768 for every device. | ||
414 | ------------------------------------------------------------------------------- | ||
415 | Name: colour | ||
416 | Type: long array (min = 0, max = 32) | ||
417 | Syntax: <n[,...]> | ||
418 | Description: Set picture saturation (0-65535). | ||
419 | Default: 32768 for every device. | ||
420 | ------------------------------------------------------------------------------- | ||
421 | Name: contrast | ||
422 | Type: long array (min = 0, max = 32) | ||
423 | Syntax: <n[,...]> | ||
424 | Description: Set picture contrast (0-65535). | ||
425 | Default: 50000 for every device. | ||
426 | ------------------------------------------------------------------------------- | ||
427 | Name: whiteness | ||
428 | Type: long array (min = 0, max = 32) | ||
429 | Syntax: <n[,...]> | ||
430 | Description: Set picture whiteness (0-65535). | ||
431 | Default: 32768 for every device. | ||
432 | ------------------------------------------------------------------------------- | ||
433 | Name: debug | ||
434 | Type: int | ||
435 | Syntax: <n> | ||
436 | Description: Debugging information level, from 0 to 6: | ||
437 | 0 = none (use carefully) | ||
438 | 1 = critical errors | ||
439 | 2 = significant informations | ||
440 | 3 = configuration or general messages | ||
441 | 4 = warnings | ||
442 | 5 = called functions | ||
443 | 6 = function internals | ||
444 | Level 5 and 6 are useful for testing only, when only one | ||
445 | device is used. | ||
446 | Default: 2 | ||
447 | ------------------------------------------------------------------------------- | ||
448 | Name: specific_debug | ||
449 | Type: bool | ||
450 | Syntax: <0|1> | ||
451 | Description: Enable or disable specific debugging messages: | ||
452 | 0 = print messages concerning every level <= 'debug' level. | ||
453 | 1 = print messages concerning the level indicated by 'debug'. | ||
454 | Default: 0 | ||
455 | ------------------------------------------------------------------------------- | ||
456 | |||
457 | |||
458 | 9. Contact information | ||
459 | ====================== | ||
460 | I may be contacted by e-mail at <luca.risolia@studio.unibo.it>. | ||
461 | |||
462 | I can accept GPG/PGP encrypted e-mail. My GPG key ID is 'FCE635A4'. | ||
463 | My public 1024-bit key should be available at your keyserver; the fingerprint | ||
464 | is: '88E8 F32F 7244 68BA 3958 5D40 99DA 5D2A FCE6 35A4'. | ||
465 | |||
466 | |||
467 | 10. Credits | ||
468 | ========== | ||
469 | The development would not have proceed much further without having looked at | ||
470 | the source code of other drivers and without the help of several persons; in | ||
471 | particular: | ||
472 | |||
473 | - the I2C interface to kernel and high-level image sensor control routines have | ||
474 | been taken from the OV511 driver by Mark McClelland; | ||
475 | |||
476 | - memory management code has been copied from the bttv driver by Ralph Metzler, | ||
477 | Marcus Metzler and Gerd Knorr; | ||
478 | |||
479 | - the low-level I2C read function has been written by Frederic Jouault; | ||
480 | |||
481 | - the low-level I2C fast write function has been written by Piotr Czerczak. | ||