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Date:      Tue, 23 Jun 2009 11:23:32 -0500
From:      Jason Harmening <jason.harmening@gmail.com>
To:        freebsd-multimedia@freebsd.org
Subject:   Updated cx88 driver, now with PCIe!
Message-ID:  <2d1264630906230923s4aaaaa63rc283dd1ffce2eef9@mail.gmail.com>

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cx88 version 1.2.0 is now in ports.  In addition to the fix for the
userspace buffer sync panic (<sarcasm>I'm awesome!</sarcasm>) and some
cleanup of the internal driver architecture, this release adds kernel
driver support for CX23885/7/8-based PCIe cards.

Datasheets for the CX23885 family are not publicly available, but this
support was made possible by the hard work of Konstantin Dimitrov. He
did a great deal of clean-room research into the register-level
programming interfaces for the CX23885/7/8, and was ultimately able to
determine their SRAM layout and much of the required I2C and MPEG
transport stream control logic. We were able to fill in all the
remaining gaps based on our existing knowledge of the CX23880 family
and correlation of observed behavior with the register constants
declared in the Linux CX23885 driver source code.

The net result of this effort is a very clean driver enhancement--All
of the fundamental DMA and I2C logic is integrated into the common
code base with leverage of existing cx88 infrastructure and relatively
little added code. Common MPEG routines have been moved to
cx88mpegcore.ko, which also exposes the /dev/cx88mpeg* device nodes,
so the nodes are ioctl(2)-compatible. cx88mpeg.ko is now a thin
CX23880-specific wrapper around cx88mpegcore, while cx23885.ko is a
thin CX23885-family wrapper for all device interfaces that may be used
with CX23885/7/8 devices (currently only cx88mpegcore).

This support is currently MPEG-only. We will consider adding support
for other streams (analog, MPEG encoders, etc.) as need arises.

As usual, the kernel drivers should attach to any CX23885/7/8 device.
The initial CX23885-family cards supported in userspace are the
Hauppauge WinTV HVR-1250 and HVR-1800.  Unfortunately, these are not
dual-HDTV cards.  Each has one MPEG transport stream attached to the
digital TV frontend, while the 1800 has the other transport stream
attached to the analog frontend via a hardware encoder.  I'll shortly
begin work on support for the DViCO Fusion 7 Dual, which *is* a
dual-HDTV card.
Konstantin is also working on support for DVB-T CX23885/7/8 cards,
namely the HVR-1200 and HVR-1700.  He has successfully captured TV
streams with them, but they have complex tuners/demodulators that need
a lot of work to polish.

There are also new tunables for enabling I2C polling (for those RT
people who don't like lots of interrupts) and for enabling message
signaled interrupts (PCIe-only).  See the wiki for details.

Please join me in giving a shout-out to Konstantin--without his hard
work I'd still be sitting here waiting for a datasheet to fall from
the sky.

--Jason



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