Re: [PATCH 2/3] spi: orion: enable support for switching CS every transferred byte

[Marcin Wojtas <mw@xxxxxxxxxxxx>]

czw., 17 gru 2020 o 15:15 Mark Brown <broonie@xxxxxxxxxx> napisał(a):
>
> On Thu, Dec 17, 2020 at 01:27:07PM +0200, kostap@xxxxxxxxxxx wrote:
>
> > Some SPI devices, such as SLIC (Subscriber Line Interface Card)
> > require toggling the CS every transferred byte. Enable such
> > possibility by creating a new DT property and enabling SPI
> > device mode update. Add according support in the spi-orion driver.
>
> I'm pretty sure we already support this - if the client driver sets the
> word length to 8 bits then SPI_CS_WORD ought to do what your change
> describes as far as I can see.  What's missing there?

Sure, that needs to be confirmed on HW, but it looks like the required
functionality can be handled with SPI_CS_WORD.

As for the justification, the new flag was developed on a kernel
revision without it and applied easily, hence the possible oversight.

>
> > ---
> >  drivers/spi/spi-orion.c | 20 +++++++++++++++++++-
> >  drivers/spi/spi.c       |  6 ++++--
> >  include/linux/spi/spi.h |  1 +
> >  3 files changed, 24 insertions(+), 3 deletions(-)
>
> This is introducing something into the core and adding a user of it, it
> should be two separate patches.

Agree.

Thanks,
Marcin