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1 | |
2 | ZC0301 Image Processor and Control Chip | |
3 | Driver for Linux | |
4 | ======================================= | |
5 | ||
6 | - Documentation - | |
7 | ||
8 | ||
9 | Index | |
10 | ===== | |
11 | 1. Copyright | |
12 | 2. Disclaimer | |
13 | 3. License | |
14 | 4. Overview and features | |
15 | 5. Module dependencies | |
16 | 6. Module loading | |
17 | 7. Module parameters | |
18 | 8. Supported devices | |
19 | 9. Notes for V4L2 application developers | |
20 | 10. Contact information | |
21 | 11. Credits | |
22 | ||
23 | ||
24 | 1. Copyright | |
25 | ============ | |
26 | Copyright (C) 2006 by Luca Risolia <luca.risolia@studio.unibo.it> | |
27 | ||
28 | ||
29 | 2. Disclaimer | |
30 | ============= | |
31 | This software is not developed or sponsored by Z-Star Microelectronics Corp. | |
32 | Trademarks are property of their respective owner. | |
33 | ||
34 | ||
35 | 3. License | |
36 | ========== | |
37 | This program is free software; you can redistribute it and/or modify | |
38 | it under the terms of the GNU General Public License as published by | |
39 | the Free Software Foundation; either version 2 of the License, or | |
40 | (at your option) any later version. | |
41 | ||
42 | This program is distributed in the hope that it will be useful, | |
43 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
44 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
45 | GNU General Public License for more details. | |
46 | ||
47 | You should have received a copy of the GNU General Public License | |
48 | along with this program; if not, write to the Free Software | |
49 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
50 | ||
51 | ||
52 | 4. Overview and features | |
53 | ======================== | |
54 | This driver supports the video interface of the devices mounting the ZC0301 | |
55 | Image Processor and Control Chip. | |
56 | ||
57 | The driver relies on the Video4Linux2 and USB core modules. It has been | |
58 | designed to run properly on SMP systems as well. | |
59 | ||
60 | The latest version of the ZC0301 driver can be found at the following URL: | |
61 | http://www.linux-projects.org/ | |
62 | ||
63 | Some 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; | |
9e47a52b | 70 | - video format is standard JPEG; |
60f78052 LR |
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 | ||
78 | 5. Module dependencies | |
79 | ====================== | |
80 | For it to work properly, the driver needs kernel support for Video4Linux and | |
81 | USB. | |
82 | ||
83 | The following options of the kernel configuration file must be enabled and | |
84 | corresponding modules must be compiled: | |
85 | ||
86 | # Multimedia devices | |
87 | # | |
88 | CONFIG_VIDEO_DEV=m | |
89 | ||
90 | # USB support | |
91 | # | |
92 | CONFIG_USB=m | |
93 | ||
94 | In addition, depending on the hardware being used, the modules below are | |
95 | necessary: | |
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 | ||
103 | The ZC0301 controller also provides a built-in microphone interface. It is | |
104 | supported 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 | ||
118 | And finally: | |
119 | ||
120 | # USB Multimedia devices | |
121 | # | |
122 | CONFIG_USB_ZC0301=m | |
123 | ||
124 | ||
125 | 6. Module loading | |
126 | ================= | |
127 | To use the driver, it is necessary to load the "zc0301" module into memory | |
128 | after every other module required: "videodev", "usbcore" and, depending on | |
129 | the USB host controller you have, "ehci-hcd", "uhci-hcd" or "ohci-hcd". | |
130 | ||
131 | Loading can be done as shown below: | |
132 | ||
133 | [root@localhost home]# modprobe zc0301 | |
134 | ||
135 | At this point the devices should be recognized. You can invoke "dmesg" to | |
136 | analyze kernel messages and verify that the loading process has gone well: | |
137 | ||
138 | [user@localhost home]$ dmesg | |
139 | ||
140 | ||
141 | 7. Module parameters | |
142 | ==================== | |
143 | Module parameters are listed below: | |
144 | ------------------------------------------------------------------------------- | |
145 | Name: video_nr | |
146 | Type: short array (min = 0, max = 64) | |
147 | Syntax: <-1|n[,...]> | |
148 | Description: Specify V4L2 minor mode number: | |
149 | -1 = use next available | |
150 | n = use minor number n | |
151 | You can specify up to 64 cameras this way. | |
152 | For example: | |
153 | video_nr=-1,2,-1 would assign minor number 2 to the second | |
154 | registered camera and use auto for the first one and for every | |
155 | other camera. | |
156 | Default: -1 | |
157 | ------------------------------------------------------------------------------- | |
158 | Name: force_munmap | |
159 | Type: bool array (min = 0, max = 64) | |
160 | Syntax: <0|1[,...]> | |
161 | Description: Force the application to unmap previously mapped buffer memory | |
162 | before calling any VIDIOC_S_CROP or VIDIOC_S_FMT ioctl's. Not | |
163 | all the applications support this feature. This parameter is | |
164 | specific for each detected camera. | |
165 | 0 = do not force memory unmapping | |
166 | 1 = force memory unmapping (save memory) | |
167 | Default: 0 | |
168 | ------------------------------------------------------------------------------- | |
a8474239 LR |
169 | Name: frame_timeout |
170 | Type: uint array (min = 0, max = 64) | |
171 | Syntax: <n[,...]> | |
172 | Description: Timeout for a video frame in seconds. This parameter is | |
173 | specific for each detected camera. This parameter can be | |
174 | changed at runtime thanks to the /sys filesystem interface. | |
175 | Default: 2 | |
176 | ------------------------------------------------------------------------------- | |
60f78052 LR |
177 | Name: debug |
178 | Type: ushort | |
179 | Syntax: <n> | |
180 | Description: Debugging information level, from 0 to 3: | |
181 | 0 = none (use carefully) | |
182 | 1 = critical errors | |
183 | 2 = significant informations | |
184 | 3 = more verbose messages | |
185 | Level 3 is useful for testing only, when only one device | |
186 | is used at the same time. It also shows some more informations | |
187 | about the hardware being detected. This module parameter can be | |
188 | changed at runtime thanks to the /sys filesystem interface. | |
189 | Default: 2 | |
190 | ------------------------------------------------------------------------------- | |
191 | ||
192 | ||
193 | 8. Supported devices | |
194 | ==================== | |
195 | None of the names of the companies as well as their products will be mentioned | |
196 | here. They have never collaborated with the author, so no advertising. | |
197 | ||
198 | From the point of view of a driver, what unambiguously identify a device are | |
199 | its vendor and product USB identifiers. Below is a list of known identifiers of | |
200 | devices mounting the ZC0301 Image Processor and Control Chips: | |
201 | ||
202 | Vendor ID Product ID | |
203 | --------- ---------- | |
6e0755a4 LR |
204 | 0x041e 0x4017 |
205 | 0x041e 0x401c | |
206 | 0x041e 0x401e | |
207 | 0x041e 0x4034 | |
208 | 0x041e 0x4035 | |
60f78052 | 209 | 0x046d 0x08ae |
a8474239 | 210 | 0x0ac8 0x0301 |
6e0755a4 | 211 | 0x10fd 0x8050 |
60f78052 | 212 | |
a8474239 LR |
213 | The list above does not imply that all those devices work with this driver: up |
214 | until now only the ones that mount the following image sensors are supported; | |
215 | kernel messages will always tell you whether this is the case: | |
60f78052 LR |
216 | |
217 | Model Manufacturer | |
218 | ----- ------------ | |
219 | PAS202BCB PixArt Imaging, Inc. | |
220 | ||
60f78052 LR |
221 | |
222 | 9. Notes for V4L2 application developers | |
223 | ======================================== | |
224 | This driver follows the V4L2 API specifications. In particular, it enforces two | |
225 | rules: | |
226 | ||
227 | - exactly one I/O method, either "mmap" or "read", is associated with each | |
228 | file descriptor. Once it is selected, the application must close and reopen the | |
229 | device to switch to the other I/O method; | |
230 | ||
231 | - although it is not mandatory, previously mapped buffer memory should always | |
232 | be unmapped before calling any "VIDIOC_S_CROP" or "VIDIOC_S_FMT" ioctl's. | |
233 | The same number of buffers as before will be allocated again to match the size | |
234 | of the new video frames, so you have to map the buffers again before any I/O | |
235 | attempts on them. | |
236 | ||
60f78052 LR |
237 | |
238 | 10. Contact information | |
239 | ======================= | |
240 | The author may be contacted by e-mail at <luca.risolia@studio.unibo.it>. | |
241 | ||
242 | GPG/PGP encrypted e-mail's are accepted. The GPG key ID of the author is | |
243 | 'FCE635A4'; the public 1024-bit key should be available at any keyserver; | |
244 | the fingerprint is: '88E8 F32F 7244 68BA 3958 5D40 99DA 5D2A FCE6 35A4'. | |
245 | ||
246 | ||
247 | 11. Credits | |
248 | =========== | |
9e47a52b LR |
249 | - Informations about the chip internals needed to enable the I2C protocol have |
250 | been taken from the documentation of the ZC030x Video4Linux1 driver written | |
251 | by Andrew Birkett <andy@nobugs.org>; | |
a8474239 | 252 | - The initialization values of the ZC0301 controller connected to the PAS202BCB |
9e47a52b LR |
253 | image sensor have been taken from the SPCA5XX driver maintained by |
254 | Michel Xhaard <mxhaard@magic.fr>. |