Re: [PATCH] spi: spi-gpio: Add check for cs-gpios dt property

From: Gerlando Falauto
Date: Wed Nov 13 2013 - 09:33:16 EST


Hi Mark,

On 11/13/2013 02:33 PM, Mark Brown wrote:
On Wed, Nov 13, 2013 at 09:02:28AM +0100, Gerlando Falauto wrote:
The bindings assumed that the cs-gpios property is always there.
However, a single SPI device can also work fine without an explicit chip select.
Use the SPI_GPIO_NO_CHIPSELECT mode when the property is not present or invaild.

Given that for most systems a missing /CS would be an error it seems
better to add an explicit property to enable this in order to help make
problems with the more common case more obvious.


Thank you for your answer.
How about an empty

cs-gpios;

property? To explicitly state we haven't just forgotten it -- we just know we don't have one instead. (There are plenty of empty "ranges;" properties in ARM DTSes -- I don't know if the use case is the same though).

Or else a null-valued

cs-gpios = <0>;

property?

I'm open to other proposals of course.

Thanks again!
Gerlando
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