Re: [PATCHv2] wlcore: spi: add wl18xx support

Arnd Bergmann
2016-04-17T22:19:56Z

On Sunday 10 April 2016 07:37:23 Reizer, Eyal wrote:
> Add support for using with both wl12xx and wl18xx.
>
> - 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 <eyalr@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.

Arnd