New port: pvrxxx for Hauppauge PVR150/500

[Rick C. Petty]

On Mon, Oct 16, 2006 at 05:52:21PM +1000, Ian Smith wrote:
> 
> Even bit-banging, I expect that it should be able to service interrupts
> between bytes - though not between bits, obviously - at least while

Why obviously?  There's a clock line, so I can't see why pausing even
between the bits would hurt anything...  so long as your transfer rate is
below the 400 kbit/s throughput.  I've done a lot of Atmel AVR i2c myself,
even with direct bit-banging it seems to work just fine.  Of course, if you
could offload the bus timing you would see a huge performance gain, but
that's not possible AFAIK in this case.

> transmitting.  I have very little experience with iic, but am currently
> boning up on it for a board using two Atmel AVR processors connected by
> iic via optocouplers.  Even long delays between transmitted bytes should
> be no problem unless the receiver has some unusual? timing requirements.

Just the 400 kbit/s max.  Try inserting delays between the bits.  It should
still work fine, as long as you transfer the appropriate number of bits.

> I've had a few quick forays through iicbb and all in /sys/dev/iicbus but
> admit to not making much sense of it compared to the simple AVR-asm code
> I've been studying, especially regarding the various bus layers, but it
> does appear that iicbb is pretty long in the tooth ('98?)

The iicbb could use some cleaning up.  I could take a look at it if no one
else has the time/ability.

-- Rick C. Petty