by Hello world,
I'm currently starting the development of a driver for the
Philips SAA7146 (Multimedia-to-PCI-Bridge), which can be found
on the Siemens/Nixdorf 'MXB' TV-board, as well as on the audioboard
Audiowerk8 from Emagic. In a second step, video and audio applications
must be written for these boards, with an initial focus on displaying
TV in an X window with the SNI board.
If there is already any activity in this direction, I would like to
here from it, so that work can be coordinated.
Here is the current status of the project:
A first version of a kernel module has been programmed. To read or
write the SAA7146 registers, which all are located in memory space (and
not in I/O space), the read(), write(), and ioctl() functions
together with a device special file are used. The idea is to set
a register address with ioctl(), and then just read() from or write() to
the device special file.
Open issues are:
What additional features should be implemented into the lowlevel driver
(e.g. predefined operating modes selectable via ioctl()), and what should
be left to the application?
Is there a standard way to get the base address of the video memory
(e.g. on S3-968 video graphics cards, it is the value of the PCI
configuration space register 0x10)? Does the X server maintain this
value somewhere?
If you have any comments or are interested in further details, please
e-mail me. Use "SPCI" in the subject for reference to this posting.
Thanks,
Andreas Beckmann
--------
Andreas Beckmann, Philips Semiconductors Hamburg (Germany)
Dept.: Multimedia PC - Product Development
Phone: +49-40-5613-3258 Fax: +49-40-5613-3365