On Monday 17 August 2009, H Hartley Sweeten wrote:
> Hello David,
> 
> I'm getting ready to post a SPI master driver for the EP93xx ARM processor.
> Before I do I have a question.
> 
> My driver uses a work queue to process the struct spi_message's for the
> devices.  It pulls each message out of the queue and then process all the
> struct spi_transfer's for the message.  At the start of the message the
> appropriate clock rate, SPI mode and bits/word are setup.  Then the device
> is chip selected followed by actually sending/receiving the data for the
> transfer.

Sounds right.


> My question is, if a message is composed of multiple transfers, is it possible
> for the speed to change mid message?

Yes; spi_transfer.speed_hz can override the default
setting in spi_device.


> If it is, does this need to be handled? 

Either handle it or reject transfers which try using
that mechanism before queueing them up.

- Dave



------------------------------------------------------------------------------
Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day 
trial. Simplify your report design, integration and deployment - and focus on 
what you do best, core application coding. Discover what's new with 
Crystal Reports now.  http://p.sf.net/sfu/bobj-july
_______________________________________________
spi-devel-general mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/spi-devel-general

Reply via email to