On Thu, 24 Nov 2016 20:55:17 +0100 Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote: > On Tue, Nov 22, 2016 at 06:06:16PM +0100, Emmanuel Vadot wrote: > > The spi0 controller on the A20 have up to 4 CS (Chip Select) while the > > others three only have 1. > > Add the num-cs property to each node. > > > > Signed-off-by: Emmanuel Vadot <manu@xxxxxxxxxxxxxxxx> > > I don't think we have any code that uses it at the moment. What is the > rationale behind this patch? > > Thanks! > Maxime > > -- > Maxime Ripard, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com Hi Maxime, If num-cs isn't present nothing prevent to start a transfer with a non-valid CS pin, resulting in an error. num-cs are default property especially made for this and a SPI driver should try to get the property at probe/attach time. Cheers, -- Emmanuel Vadot <manu@xxxxxxxxxxxxxxxx> <manu@xxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
