quoted

- 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 <redacted>

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



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