Root/Documentation/video4linux/zc0301.txt

1
2          ZC0301 and ZC0301P Image Processor and Control Chip
3                Driver for Linux
4          ===================================================
5
6                   - Documentation -
7
8
9Index
10=====
111. Copyright
122. Disclaimer
133. License
144. Overview and features
155. Module dependencies
166. Module loading
177. Module parameters
188. Supported devices
199. Notes for V4L2 application developers
2010. Contact information
2111. Credits
22
23
241. Copyright
25============
26Copyright (C) 2006-2007 by Luca Risolia <luca.risolia@studio.unibo.it>
27
28
292. Disclaimer
30=============
31This software is not developed or sponsored by Z-Star Microelectronics Corp.
32Trademarks are property of their respective owner.
33
34
353. License
36==========
37This program is free software; you can redistribute it and/or modify
38it under the terms of the GNU General Public License as published by
39the Free Software Foundation; either version 2 of the License, or
40(at your option) any later version.
41
42This program is distributed in the hope that it will be useful,
43but WITHOUT ANY WARRANTY; without even the implied warranty of
44MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
45GNU General Public License for more details.
46
47You should have received a copy of the GNU General Public License
48along with this program; if not, write to the Free Software
49Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
50
51
524. Overview and features
53========================
54This driver supports the video interface of the devices mounting the ZC0301 or
55ZC0301P Image Processors and Control Chips.
56
57The driver relies on the Video4Linux2 and USB core modules. It has been
58designed to run properly on SMP systems as well.
59
60The latest version of the ZC0301[P] driver can be found at the following URL:
61http://www.linux-projects.org/
62
63Some of the features of the driver are:
64
65- full compliance with the Video4Linux2 API (see also "Notes for V4L2
66  application developers" paragraph);
67- available mmap or read/poll methods for video streaming through isochronous
68  data transfers;
69- automatic detection of image sensor;
70- video format is standard JPEG;
71- dynamic driver control thanks to various module parameters (see "Module
72  parameters" paragraph);
73- up to 64 cameras can be handled at the same time; they can be connected and
74  disconnected from the host many times without turning off the computer, if
75  the system supports hotplugging;
76
77
785. Module dependencies
79======================
80For it to work properly, the driver needs kernel support for Video4Linux and
81USB.
82
83The following options of the kernel configuration file must be enabled and
84corresponding modules must be compiled:
85
86    # Multimedia devices
87    #
88    CONFIG_VIDEO_DEV=m
89
90    # USB support
91    #
92    CONFIG_USB=m
93
94In addition, depending on the hardware being used, the modules below are
95necessary:
96
97    # USB Host Controller Drivers
98    #
99    CONFIG_USB_EHCI_HCD=m
100    CONFIG_USB_UHCI_HCD=m
101    CONFIG_USB_OHCI_HCD=m
102
103The ZC0301 controller also provides a built-in microphone interface. It is
104supported by the USB Audio driver thanks to the ALSA API:
105
106    # Sound
107    #
108    CONFIG_SOUND=y
109
110    # Advanced Linux Sound Architecture
111    #
112    CONFIG_SND=m
113
114    # USB devices
115    #
116    CONFIG_SND_USB_AUDIO=m
117
118And finally:
119
120    # V4L USB devices
121    #
122    CONFIG_USB_ZC0301=m
123
124
1256. Module loading
126=================
127To use the driver, it is necessary to load the "zc0301" module into memory
128after every other module required: "videodev", "v4l2_common", "compat_ioctl32",
129"usbcore" and, depending on the USB host controller you have, "ehci-hcd",
130"uhci-hcd" or "ohci-hcd".
131
132Loading can be done as shown below:
133
134    [root@localhost home]# modprobe zc0301
135
136At this point the devices should be recognized. You can invoke "dmesg" to
137analyze kernel messages and verify that the loading process has gone well:
138
139    [user@localhost home]$ dmesg
140
141
1427. Module parameters
143====================
144Module parameters are listed below:
145-------------------------------------------------------------------------------
146Name: video_nr
147Type: short array (min = 0, max = 64)
148Syntax: <-1|n[,...]>
149Description: Specify V4L2 minor mode number:
150        -1 = use next available
151         n = use minor number n
152        You can specify up to 64 cameras this way.
153        For example:
154        video_nr=-1,2,-1 would assign minor number 2 to the second
155        registered camera and use auto for the first one and for every
156        other camera.
157Default: -1
158-------------------------------------------------------------------------------
159Name: force_munmap
160Type: bool array (min = 0, max = 64)
161Syntax: <0|1[,...]>
162Description: Force the application to unmap previously mapped buffer memory
163        before calling any VIDIOC_S_CROP or VIDIOC_S_FMT ioctl's. Not
164        all the applications support this feature. This parameter is
165        specific for each detected camera.
166        0 = do not force memory unmapping
167        1 = force memory unmapping (save memory)
168Default: 0
169-------------------------------------------------------------------------------
170Name: frame_timeout
171Type: uint array (min = 0, max = 64)
172Syntax: <n[,...]>
173Description: Timeout for a video frame in seconds. This parameter is
174        specific for each detected camera. This parameter can be
175        changed at runtime thanks to the /sys filesystem interface.
176Default: 2
177-------------------------------------------------------------------------------
178Name: debug
179Type: ushort
180Syntax: <n>
181Description: Debugging information level, from 0 to 3:
182        0 = none (use carefully)
183        1 = critical errors
184        2 = significant information
185        3 = more verbose messages
186        Level 3 is useful for testing only, when only one device
187        is used at the same time. It also shows some information
188        about the hardware being detected. This module parameter can be
189        changed at runtime thanks to the /sys filesystem interface.
190Default: 2
191-------------------------------------------------------------------------------
192
193
1948. Supported devices
195====================
196None of the names of the companies as well as their products will be mentioned
197here. They have never collaborated with the author, so no advertising.
198
199From the point of view of a driver, what unambiguously identify a device are
200its vendor and product USB identifiers. Below is a list of known identifiers of
201devices mounting the ZC0301 Image Processor and Control Chips:
202
203Vendor ID Product ID
204--------- ----------
2050x041e 0x4017
2060x041e 0x401c
2070x041e 0x401e
2080x041e 0x401f
2090x041e 0x4022
2100x041e 0x4034
2110x041e 0x4035
2120x041e 0x4036
2130x041e 0x403a
2140x0458 0x7007
2150x0458 0x700c
2160x0458 0x700f
2170x046d 0x08ae
2180x055f 0xd003
2190x055f 0xd004
2200x0ac8 0x0301
2210x0ac8 0x301b
2220x0ac8 0x303b
2230x10fd 0x0128
2240x10fd 0x8050
2250x10fd 0x804e
226
227The list above does not imply that all those devices work with this driver: up
228until now only the ones that mount the following image sensors are supported;
229kernel messages will always tell you whether this is the case:
230
231Model Manufacturer
232----- ------------
233PAS202BCB PixArt Imaging, Inc.
234PB-0330 Photobit Corporation
235
236
2379. Notes for V4L2 application developers
238========================================
239This driver follows the V4L2 API specifications. In particular, it enforces two
240rules:
241
242- exactly one I/O method, either "mmap" or "read", is associated with each
243file descriptor. Once it is selected, the application must close and reopen the
244device to switch to the other I/O method;
245
246- although it is not mandatory, previously mapped buffer memory should always
247be unmapped before calling any "VIDIOC_S_CROP" or "VIDIOC_S_FMT" ioctl's.
248The same number of buffers as before will be allocated again to match the size
249of the new video frames, so you have to map the buffers again before any I/O
250attempts on them.
251
252
25310. Contact information
254=======================
255The author may be contacted by e-mail at <luca.risolia@studio.unibo.it>.
256
257GPG/PGP encrypted e-mail's are accepted. The GPG key ID of the author is
258'FCE635A4'; the public 1024-bit key should be available at any keyserver;
259the fingerprint is: '88E8 F32F 7244 68BA 3958 5D40 99DA 5D2A FCE6 35A4'.
260
261
26211. Credits
263===========
264- Information about the chip internals needed to enable the I2C protocol have
265  been taken from the documentation of the ZC030x Video4Linux1 driver written
266  by Andrew Birkett <andy@nobugs.org>;
267- The initialization values of the ZC0301 controller connected to the PAS202BCB
268  and PB-0330 image sensors have been taken from the SPCA5XX driver maintained
269  by Michel Xhaard <mxhaard@magic.fr>;
270- Stanislav Lechev donated one camera.
271

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