Re: [PATCH] ARM: dts: exynos: Fix invalid maximum voltage for buck9 supplying SD card

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On Thu, Mar 24, 2016 at 6:53 PM, Mark Brown <broonie@xxxxxxxxxx> wrote:
> On Thu, Mar 24, 2016 at 05:12:05PM +0900, Krzysztof Kozlowski wrote:
>
>>                       buck9_reg: BUCK9 {
>>                               regulator-name = "vdd_2.8v_ldo";
>>                               regulator-min-microvolt = <3000000>;
>> -                             regulator-max-microvolt = <3750000>;
>> +                             regulator-max-microvolt = <3755000>;
>>                               regulator-always-on;
>>                               regulator-boot-on;
>>                       };
>
> Why does this regulator even have voltage constraints configured?  Is
> there any intention that it should ever be varied at runtime?

Good question. I was also wondering that, if tetting it by 5 mV lower
causes failure, then the constraints are actually fixed at 3.755 V. I
do not know the answer. Boards schematics do not specify the
requirement here, datasheet for PMIC says default value of 3.4V. Heh,
maybe the regulator driver is missing proper starting value for 'vsel'
(datasheet says values in register start from 0x40 -> 3 V). Something
looks wrong here...

I'll look at it after weekend. For now I applied my patch to the
for-next, so the next should be fixed.

Best regards,
Krzysztof
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux