Re: [PATCH 00/13] Ingenic JZ4740 / JZ4780 pinctrl driver

From: Linus Walleij
Date: Thu Jan 19 2017 - 01:40:31 EST


On Wed, Jan 18, 2017 at 12:14 AM, Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote:

> One problem still unresolved: the pinctrl framework does not allow us to
> configure each pin on demand (someone please prove me wrong), when the
> various PWM channels are requested or released. For instance, the PWM
> channels can be configured from sysfs, which would require all PWM pins
> to be configured properly beforehand for the PWM function, eventually
> causing conflicts with other platform or board drivers.

Why do you think this?

- Pincontrol handles can be obtained at runtime.
- Pincontrol states can be changed at runtime.

The fact that a the handle is retrived by the device core and set to
the states named "init" or "default" during boot is just a convenience.

You can have as many and as fine-grained states as you want. They
can pertain to just one pin too.

Linus Walleij