On Thu, Nov 26, 2009 at 12:01 PM, Anton Vorontsov <avoront...@ru.mvista.com> wrote: > On Thu, Nov 26, 2009 at 11:50:05AM -0700, Grant Likely wrote: >> On Thu, Nov 26, 2009 at 11:41 AM, Anton Vorontsov >> <avoront...@ru.mvista.com> wrote: >> > On Thu, Nov 26, 2009 at 11:16:34AM -0700, Grant Likely wrote: >> > [...] >> >> The spi-cs-high property is defined in >> >> Documentation/powerpc/dts-bindings/spi-bus.txt, but it definitely was >> >> a mistake >> > >> > Yup. >> > >> >> Currently the spi-cs-high property is parsed in the >> >> of_register_spi_devices() function, but the CS polarity needs to be >> >> known before registering devices. It needs to be factored out into >> >> another utility function callable by spi bus drivers so that it can >> >> get polarity data at probe time. >> > >> > Untill we have this, Torsten's patch is a real improvement, and >> > works for non-broken hw/fw. >> > >> > So I think it should be applied. >> >> I disagree since it only band-aids the problem and uglifies the driver >> in the process. In the immediate term the driver needs to be changed >> to read the spi-cs-high property out of the child nodes before >> registering the devices. > > Hm. I thought we agreed that spi-cs-high is not good? Why do you > encourage using it then? We'll have to uglify the driver with > legacy device-tree handling code.
spi-cs-high is definitely not a complete solution, but it isn't actively evil either. Plus it is documented and (presumably) in active use. so support for it should not be dropped. Regardless, there needs to be a library function for parsing all the SPI child nodes and returning the active state for each GPIO chip select. All the code for parsing the old spi-cs-high properties can be contained in the same place as a new yet-to-be-defined bus node cs polarity property. The rework to the driver itself is not ugly. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev