Re: [PATCH 2/2] pinctrl: single: Allow indicating loss of pin states during low-power

From: Florian Fainelli
Date: Mon Sep 25 2017 - 15:16:01 EST


On 09/22/2017 06:03 AM, Linus Walleij wrote:
> On Thu, Sep 21, 2017 at 3:04 AM, Florian Fainelli <f.fainelli@xxxxxxxxx> wrote:
>
>> Some platforms (e.g: Broadcom STB: BMIPS_GENERIC/ARCH_BRCMSTB) will lose
>> their register contents when entering their lower power state. In such a
>> case, the pinctrl-single driver that is used will not be able to restore
>> the power states without telling the core about it and having
>> pinctrl_select_state() check for that.
>>
>> This patch adds a new optional boolean property that Device Tree can
>> define in order to obtain exactly that and having the core pinctrl code
>> take that into account.
>>
>> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
>
> If we use this per-controller approach rather than the per-state approach
> I discuss in reply to patch 1/2, we should probably make it a generic
> property for pin controllers and not just a pinctrl-single business.

I suppose it makes sense to make this a generic pinctrl property then.
drivers/pinctrl/core.c does not appear to be trying to fetch any
properties for a pinctrl device, but that is probably not too hard to add.

>
> So patch pinctrl-bindings.txt and put the code somewhere in
> core.
>
> But that is more of a detail, first we need to figure out how to
> handle this business in general.

Fair enough.
--
Florian