> > > > - all wilink family needs special init command for entering wspi mode. > > extra clock cycles should be sent after the spi init command while the > > cs pin is high. > > - switch to controling the cs pin from the spi driver for achieveing the > > above. > > - the selected cs gpio is read from the spi device-tree node using the > > cs-gpios field and setup as a gpio. > > - See the example below for specifying the cs gpio using the cs-gpios entry > > &spi0 { > > ... > > cs-gpios = <&gpio0 5 0>; > > ... > > wlcore: wlcore@0 { > > compatible = "ti,wl1835"; > > ... > > ... > > }; > > }; > > > > Signed-off-by: Eyal Reizer <ey...@ti.com> > > I don't think this can work in general: not all SPI hosts uses GPIOs for > controlling CS, so the logic can't work, and it's also a layering violation > for the > driver to look at the parent. > > I would suggest fixing this using a new API function from the SPI core, if we > don't already have a generic way to do it. > Originally this is what I have done until I was pointed to the generic cs-gpio mechanism in the SPI core. It is a generic mechanism already in the SPI core driver. See: Documentation/devicetree/bindings/spi/spi-bus.txt
It is also part of the generic spi.h (include/Linux/spi/spi.h), already part of " struct spi_device" So it seemed redundant adding another mechanism for implementing the same. Platform that interact with a wilink need to use it, and platforms that don't have this capability will probably not interact with a wilink device using SPI. Best Regards, Eyal