Re: [PATCH v7] regulator: fixed: Convert to use GPIO descriptor only

[Linus Walleij]

On Fri, Oct 12, 2018 at 12:43 PM Russell King - ARM Linux
<linux@xxxxxxxxxxxxxxx> wrote:

> Given that DT describes the hardware, not the software implementation,
> it must not change just because we move from GPIO numbers to GPIO
> descriptors.
>
> The existing DT description is reasonable, and introducing ficticious
> regulators in DT to work around the implementation is not reasonable.

You're right. In the electronics and the device tree it
makes perfect sense for the same line to enable/disable several
regulators.

The patch I made is a quick hack to allow multiple users of the
same descriptor, I think the long term fix is simply allow multiple
users where applicable and maintain a reference count just like
the regulator core is doing, assert the GPIO when the first
consumer asserts it and de-assert it when the last consumer
de-asserts it.

What the old and current gpiolib does us just
call the callback to enable/disable the line immediately as
response to the callback asserting/deasserting the GPIO,
which is just too simplified.

Yours,
Linus Walleij