Re: [PATCH v4 1/3] pinctrl: Add sleep related configuration

Baolin Wang
2017-07-13T06:35:27Z

Hi,

On 12 July 2017 at 20:30, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Tue, Jun 27, 2017 at 2:06 PM, Baolin Wang <baolin.wang@spreadtrum.com> wrote:
>
>> If we introduce "sleep-input-enable" config, we can set the pin's config
>> as below:
>>
>> vio_sd0_ms_3: regctrl3 {
>> pins = "SC9860_RFCTL30", "SC9860_RFCTL31", "SC9860_RFCTL32";
>> function = "func1";
>> sprd,sleep-mode = <0x3>;
>> sleep-input-enable;
>> };
>
> This looks like a "default" mode. Is that correct?

This can be not default. In some situation, user can change the pins
function and other config.

> I.e. do you set up this on probe then do not touch it?
>
> It seems some of the problems come from the insistance to use a single
> node for all configuration. Compare to this nomadik:
>
> i2c0 {
> i2c0_default_mux: i2c0_mux {
> i2c0_default_mux {
> function = "i2c0";
> groups = "i2c0_a_1";
> };
> };
> i2c0_default_mode: i2c0_default {
> i2c0_default_cfg {
> pins = "GPIO62_D3", "GPIO63_D2";
> input-enable;
> };
> };
> };
>
> It is easy to imagine:
>
> i2c0 {
> i2c0_default_mux: i2c0_mux {
> i2c0_default_mux {
> function = "i2c0";
> groups = "i2c0_a_1";
> };
> };
> i2c0_default_mode: i2c0_default {
> i2c0_default_cfg {
> pins = "GPIO62_D3", "GPIO63_D2";
> input-enable;
> };
> };
> i2c0_default_mode_sleep: i2c0_default_sleep {
> i2c0_default_cfg {
> pins = "GPIO62_D3", "GPIO63_D2";
> sleep-hardware-state;
> input-disable;
> };
> };
> };
>
> Notice the new bool property "sleep-hardware-state" that just
> indicate that this should be programmed into the registers for
> the sleep state.

That means we should introduce one "sleep-hardware-state" config.

So my instance can change to be :
grp1: regctrl3 {
pins = "SC9860_RFCTL30", "SC9860_RFCTL31", "SC9860_RFCTL32";
function = "func1";
sprd,sleep-mode = <0x3>;

grp1_sleep_mode: regctrl3_default_sleep {
pins = "SC9860_RFCTL30", "SC9860_RFCTL31", "SC9860_RFCTL32";
sleep-hardware-state;
input-enable;
}
};

That sounds reasonable and I will try to check if it can work.

>
>> But If we create one extra "sleep-xxx" state for sleep-related configs,
>> it will be like:
>>
>> grp1: regctrl3 {
>> pins = "SC9860_RFCTL30", "SC9860_RFCTL31";
>> function = "func1";
>> sprd,sleep-mode = <0x3>;
>> };
>>
>> sleep-input: input_grp {
>> pins = "SC9860_RFCTL30", "SC9860_RFCTL31", "SC9860_RFCTL32";
>> input-enable;
>> };
>>
>> pinctrl-names = "sleep-input";
>> pinctrl-0 = <&sleep-input>;
>>
>> "sleep-input" state will be selected when initializing pinctrl driver,
>
> The state you should use for initial configuration should be called
> just "init".

Yes.

>
>> "grp1"
>> will be selected by user to set other pin configuration.
>
> Like "default"?
>
>> Then we need config "SC9860_RFCTL30" pin in 2 different places, which is
>> more inconvenient for users.
>
> I'm not so sure about that. Having a lot more sleep,* config options
> may be even more inconvenient for users, and especially for the
> community of developers as a whole.

Make sense. Thanks for your suggestion.

>
> Several config nodes on the other hand, we have had in the pin
> control subsystem since day 1.
>
> Yours,
> Linus Walleij

--
Baolin.wang
Best Regards