On Mon, Aug 20, 2012 at 4:22 PM, Rob Herring <robherri...@gmail.com> wrote: > On 08/20/2012 06:39 AM, Alexandre Pereira da Silva wrote:
>> +- pl022,hierarchy : master or slave interface > > Is attaching a master and using the pl022 as a slave really a supported > use case? No not currently. People doing this crazy stuff need to have the kernel with the hard real-time patches and lightening response first. But it's in the platform data because it's a feature supported by the hardware. > The DT spi bindings are really designed for a master node with > N slave nodes. So there is more general question of how to describe a > spi controller as a slave. It's not really one I care to answer as the > Linux spi framework isn't designed to act as a slave. Currently the code should hardwire this to master and not define a binding for it I think. >> +- pl022,slave-tx-disable : disconnect tx line in slave mode Applies also to this, then. >> +- pl022,com-mode : polling, interrupt or dma >> +- pl022,rx-level-trig : Rx FIFO watermark level >> +- pl022,tx-level-trig : Tx FIFO watermark level >> +- pl022,ctrl-len : Microwire interface: Control length >> +- pl022,wait-state : Microwire interface: Wait state >> +- pl022,duplex : Microwire interface: Full/Half duplex > > Most of these properties aren't used anywhere in the kernel other than > u300 and I'm not sure what to purpose of dummy_chip_info is. It is used for loopback-testing of the PL022. They're probably not necessary there either. > Perhaps > Linus has some input? I think either they can be decided by the spi > controller (com-mode, fifo watermark) or should be standard properties > (microwire settings). I would argue they should be removed if the spi > framework doesn't have support in a standard way. Uncertain about this, others would need to comment. At some point there has been a chip needing these to be set to some magic values. Yours, Linus Walleij ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
