[PATCH] USB: Add ZC0301 Video4Linux2 driver

                    ZC0301 Image Processor and Control Chip

                                Driver for Linux

                    =======================================

                               - Documentation -

Index

=====

1.  Copyright

2.  Disclaimer

3.  License

4.  Overview and features

5.  Module dependencies

6.  Module loading

7.  Module parameters

8.  Supported devices

9.  Notes for V4L2 application developers

10. Contact information

11. Credits

1. Copyright

============

Copyright (C) 2006 by Luca Risolia <luca.risolia@studio.unibo.it>

2. Disclaimer

=============

This software is not developed or sponsored by Z-Star Microelectronics Corp.

Trademarks are property of their respective owner.

3. License

==========

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

4. Overview and features

========================

This driver supports the video interface of the devices mounting the ZC0301

Image Processor and Control Chip.

The driver relies on the Video4Linux2 and USB core modules. It has been

designed to run properly on SMP systems as well.

The latest version of the ZC0301 driver can be found at the following URL:

http://www.linux-projects.org/

Some of the features of the driver are:

- full compliance with the Video4Linux2 API (see also "Notes for V4L2

  application developers" paragraph);

- available mmap or read/poll methods for video streaming through isochronous

  data transfers;

- automatic detection of image sensor;

- video formats is standard JPEG in various compression qualities

  (see also "Notes for V4L2 application developers" paragraph);

- full support for the capabilities of every possible image sensors that can

  be connected to the ZC0301 bridges, including, for istance, red, green,

  blue and global gain adjustments and exposure control (see "Supported

  devices" paragraph for details);

- use of default color settings for sunlight conditions;

- dynamic driver control thanks to various module parameters (see "Module

  parameters" paragraph);

- up to 64 cameras can be handled at the same time; they can be connected and

  disconnected from the host many times without turning off the computer, if

  the system supports hotplugging;

5. Module dependencies

======================

For it to work properly, the driver needs kernel support for Video4Linux and

USB.

The following options of the kernel configuration file must be enabled and

corresponding modules must be compiled:

	# Multimedia devices

	#

	CONFIG_VIDEO_DEV=m

	# USB support

	#

	CONFIG_USB=m

In addition, depending on the hardware being used, the modules below are

necessary:

	# USB Host Controller Drivers

	#

	CONFIG_USB_EHCI_HCD=m

	CONFIG_USB_UHCI_HCD=m

	CONFIG_USB_OHCI_HCD=m

The ZC0301 controller also provides a built-in microphone interface. It is

supported by the USB Audio driver thanks to the ALSA API:

	# Sound

	#

	CONFIG_SOUND=y

	# Advanced Linux Sound Architecture

	#

	CONFIG_SND=m

	# USB devices

	#

	CONFIG_SND_USB_AUDIO=m

And finally:

	# USB Multimedia devices

	#

	CONFIG_USB_ZC0301=m

6. Module loading

=================

To use the driver, it is necessary to load the "zc0301" module into memory

after every other module required: "videodev", "usbcore" and, depending on

the USB host controller you have, "ehci-hcd", "uhci-hcd" or "ohci-hcd".

Loading can be done as shown below:

	[root@localhost home]# modprobe zc0301

At this point the devices should be recognized. You can invoke "dmesg" to

analyze kernel messages and verify that the loading process has gone well:

	[user@localhost home]$ dmesg

7. Module parameters

====================

Module parameters are listed below:

-------------------------------------------------------------------------------

Name:           video_nr

Type:           short array (min = 0, max = 64)

Syntax:         <-1|n[,...]>

Description:    Specify V4L2 minor mode number:

                -1 = use next available

                 n = use minor number n

                You can specify up to 64 cameras this way.

                For example:

                video_nr=-1,2,-1 would assign minor number 2 to the second

                registered camera and use auto for the first one and for every

                other camera.

Default:        -1

-------------------------------------------------------------------------------

Name:           force_munmap

Type:           bool array (min = 0, max = 64)

Syntax:         <0|1[,...]>

Description:    Force the application to unmap previously mapped buffer memory

                before calling any VIDIOC_S_CROP or VIDIOC_S_FMT ioctl's. Not

                all the applications support this feature. This parameter is

                specific for each detected camera.

                0 = do not force memory unmapping

                1 = force memory unmapping (save memory)

Default:        0

-------------------------------------------------------------------------------

Name:           debug

Type:           ushort

Syntax:         <n>

Description:    Debugging information level, from 0 to 3:

                0 = none (use carefully)

                1 = critical errors

                2 = significant informations

                3 = more verbose messages

                Level 3 is useful for testing only, when only one device

                is used at the same time. It also shows some more informations

                about the hardware being detected. This module parameter can be

                changed at runtime thanks to the /sys filesystem interface.

Default:        2

-------------------------------------------------------------------------------

8. Supported devices

====================

None of the names of the companies as well as their products will be mentioned

here. They have never collaborated with the author, so no advertising.

From the point of view of a driver, what unambiguously identify a device are

its vendor and product USB identifiers. Below is a list of known identifiers of

devices mounting the ZC0301 Image Processor and Control Chips:

Vendor ID  Product ID

---------  ----------

0x046d     0x08ae

The following image sensors are supported:

Model       Manufacturer

-----       ------------

PAS202BCB   PixArt Imaging, Inc.

All the available control settings of each image sensor are supported through

the V4L2 interface.

9. Notes for V4L2 application developers

========================================

This driver follows the V4L2 API specifications. In particular, it enforces two

rules:

- exactly one I/O method, either "mmap" or "read", is associated with each

file descriptor. Once it is selected, the application must close and reopen the

device to switch to the other I/O method;

- although it is not mandatory, previously mapped buffer memory should always

be unmapped before calling any "VIDIOC_S_CROP" or "VIDIOC_S_FMT" ioctl's.

The same number of buffers as before will be allocated again to match the size

of the new video frames, so you have to map the buffers again before any I/O

attempts on them.

This driver supports the standard JPEG video format. The current compression

quality may vary from 0 to 3 and can be selected or queried thanks to the

VIDIOC_S_JPEGCOMP and VIDIOC_G_JPEGCOMP V4L2 ioctl's.

10. Contact information

=======================

The author may be contacted by e-mail at <luca.risolia@studio.unibo.it>.

GPG/PGP encrypted e-mail's are accepted. The GPG key ID of the author is

'FCE635A4'; the public 1024-bit key should be available at any keyserver;

the fingerprint is: '88E8 F32F 7244 68BA 3958  5D40 99DA 5D2A FCE6 35A4'.

11. Credits

===========

- Informations about the chip internals to enable the I2C protocol have been

  taken from the documentation of the ZC030x Video4Linux1 driver written by

  Andrew Birkett <andy@nobugs.org>;

- Initialization values of the ZC0301 connected to the PAS202BCB image sensor

  have been taken from the SPCA5XX driver maintained by

  Michel Xhaard  <mxhaard@magic.fr>

W:	http://www.linux-projects.org

S:	Maintained

USB ZC0301 DRIVER

P:	Luca Risolia

M:	luca.risolia@studio.unibo.it

L:	linux-usb-devel@lists.sourceforge.net

L:	video4linux-list@redhat.com

W:	http://www.linux-projects.org

S:	Maintained

USB ZD1201 DRIVER

P:	Jeroen Vreeken

M:	pe1rxq@amsat.org

obj-$(CONFIG_USB_STV680)	+= media/

obj-$(CONFIG_USB_VICAM)		+= media/

obj-$(CONFIG_USB_W9968CF)	+= media/

obj-$(CONFIG_USB_ZC0301)	+= media/

obj-$(CONFIG_USB_CATC)		+= net/

obj-$(CONFIG_USB_KAWETH)	+= net/

	  To compile this driver as a module, choose M here: the

	  module will be called w9968cf.

config USB_ZC0301

	tristate "USB ZC0301 Image Processor and Control Chip support"

	depends on USB && VIDEO_DEV

	---help---

	  Say Y here if you want support for cameras based on the ZC0301

	  Image Processor and Control Chip.

	  See <file:Documentation/usb/zc0301.txt> for more informations.

	  This driver uses the Video For Linux API. You must say Y or M to

	  "Video For Linux" to use this driver.

	  To compile this driver as a module, choose M here: the

	  module will be called zc0301.

config USB_PWC

	tristate "USB Philips Cameras"

	depends on USB && VIDEO_DEV

sn9c102-objs	:= sn9c102_core.o sn9c102_hv7131d.o sn9c102_mi0343.o sn9c102_ov7630.o sn9c102_pas106b.o sn9c102_pas202bcb.o sn9c102_tas5110c1b.o sn9c102_tas5130d1b.o

et61x251-objs	:= et61x251_core.o et61x251_tas5130d1b.o

zc0301-objs	:= zc0301_core.o zc0301_pas202bcb.o

obj-$(CONFIG_USB_DABUSB)	+= dabusb.o

obj-$(CONFIG_USB_DSBR)		+= dsbr100.o

obj-$(CONFIG_USB_STV680)	+= stv680.o

obj-$(CONFIG_USB_VICAM)		+= vicam.o usbvideo.o

obj-$(CONFIG_USB_W9968CF)	+= w9968cf.o

obj-$(CONFIG_USB_ZC0301)	+= zc0301.o

obj-$(CONFIG_USB_PWC)           += pwc/