Hi Martin,
On 29.10.2020 22:40, Martin Juecker wrote:
> On Tue, Oct 27, 2020 at 09:17:51AM +0100, Krzysztof Kozlowski wrote:
>> On Tue, Oct 27, 2020 at 12:27:09AM +0100, Martin Juecker wrote:
>>>>> +
>>>>> + max77686: max77686_pmic@9 {
>>>>> + compatible = "maxim,max77686";
>>>>> + interrupt-parent = <&gpx0>;
>>>>> + interrupts = <7 IRQ_TYPE_NONE>;
>>>>> + pinctrl-0 = <&max77686_irq>;
>>>>> + pinctrl-names = "default";
>>>>> + reg = <0x09>;
>>>>> + #clock-cells = <1>;
>>>>> +
>>>>> + voltage-regulators {
>>>> Just "regulators" and no empty line after this.
>>>>
>>>> You should define all regulators here. If some are unknown, keep the
>>>> min-max the same as in driver.
>>>>
>>> I used the driver to read all the voltages, it also reads values for
>>> the LDOs that are not defined in the DT, so I have values for all of
>>> them setup by the bootloader. What I don't know is their name and what
>>> they are used for. Interestingly apart from two LDOs, the voltages did
>>> match exactly with those from the midas DT, so it could be very
>>> similar. The two non-matching were only off by 0.1V. How should I go
>>> about this?
>> Actually, let's skip the constraints (min-max) for unknown regulators.
>> Just add the entries with generic names, like:
>> arch/arm/boot/dts/exynos5410-odroidxu.dts
>>
>> I would not put here min-max constraints from bootloader because pretty
>> often it has only an initial setup for specific frequency - just to make
>> it booting.
>>
>> If you have the constraints (min-max, always on) from vendor sources,
>> you could add them.
>>
>> Best regards,
>> Krzysztof
> As all the missing regulators are not defined in the vendor sources, I
> have no constraints to work with.
>
> What I noticed when all the LDOs are defined, the device reboot
> behaviour is different. Instead of the usual 1-2 seconds for screen off
> and on again, it's now more like 10 seconds.
Then it looks that some regulators get turned off too early and shutdown
sequence encounters timeout. You can try to find which regulator is
responsible for that by adding 'always-on' property to those regulators
and doing the reboot test. Once found you may either keep it as always
on, or check in if its consumers are properly defined.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
