Re: [PATCH 1/4] dt-bindings: nvmem: new optional property write-protect-gpios

From: Linus Walleij
Date: Fri Nov 22 2019 - 07:53:22 EST


On Fri, Nov 22, 2019 at 1:47 PM Bartosz Golaszewski
<bgolaszewski@xxxxxxxxxxxx> wrote:

> what about the existing bindings for at24 that don't mandate the
> active-low flag? I'm afraid this would break the support for this
> specific chip or lead to code duplication if we had this in both nvmem
> and at24 with different logic.

Hm yeah I realized this when I read patches 3 & 4.

I would to like this:

1. Add a new generic property
writeprotect-gpios that mandates to use GPIO_ACTIVE_LOW
and use this in the new example

2. Deprecate wp-gpios in the binding, keep it around but deprecated.

3. Add a quirk to gpiolib-of in the manner of the other quirks there
(like for SPI) so that if we are dealing with some EEPROM node
like at24 and the flag is zero, tag on GPIO_ACTIVE_LOW on
the descriptor.

The driver will now handle the semantic of both cases
with gpiolib-of providing a quirk for the old binding.

This is how we solved this type of problem before.

Yours,
Linus Walleij