Re: [PATCH v5 10/10] arm64: dts: actions: Add uSD support for Cubieboard7

André Przywara
2020-07-12T23:19:30Z

On 12/07/2020 19:45, Amit Tomer wrote:

Hi,

> On Sun, Jul 12, 2020 at 11:00 PM Manivannan Sadhasivam
> <manivannan.sadhasivam@linaro.org> wrote:
>>
>> On Thu, Jul 02, 2020 at 08:22:56PM +0530, Amit Singh Tomar wrote:
>>> This commit adds uSD support for Cubieboard7 board based on Actions Semi
>>> S700 SoC. SD0 is connected to uSD slot. Since there is no PMIC support
>>> added yet, fixed regulator has been used as a regulator node.
>>>
>>> Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
>>> ---
>>> Changes since v4:
>>> * No change.
>>> Changes since v3:
>>> * No change.
>>> Changes since v2:
>>> * No change.
>>> Changes since v1:
>>> * No change.
>>> Changes since RFC:
>>> * No change.
>>> ---
>>> arch/arm64/boot/dts/actions/s700-cubieboard7.dts | 41 ++++++++++++++++++++++++
>>> arch/arm64/boot/dts/actions/s700.dtsi | 1 +
>>> 2 files changed, 42 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/actions/s700-cubieboard7.dts b/arch/arm64/boot/dts/actions/s700-cubieboard7.dts
>>> index 63e375cd9eb4..ec117eb12f3a 100644
>>> --- a/arch/arm64/boot/dts/actions/s700-cubieboard7.dts
>>> +++ b/arch/arm64/boot/dts/actions/s700-cubieboard7.dts
>>> @@ -13,6 +13,7 @@
>>>
>>> aliases {
>>> serial3 = &uart3;
>>> + mmc0 = &mmc0;
>>> };
>>>
>>> chosen {
>>> @@ -28,6 +29,23 @@
>>> device_type = "memory";
>>> reg = <0x1 0xe0000000 0x0 0x0>;
>>> };
>>> +
>>> + /* Fixed regulator used in the absence of PMIC */
>>> + vcc_3v1: vcc-3v1 {
>>> + compatible = "regulator-fixed";
>>> + regulator-name = "fixed-3.1V";
>>> + regulator-min-microvolt = <3100000>;
>>> + regulator-max-microvolt = <3100000>;
>>> + };
>>
>> Is this regulator used somewhere?
>
> This is something I copied from bubblegum dts as I wasn't sure what is right way
> to include these regulators.

But this regulator is only used for the eMMC there, which we apparently
don't have on the Cubieboard 7?

> Also, another day tested it without having these regulators in , and
> still it seems to
> work. So should these be removed ?

If there are not even referenced in the .dts, then fixed regulators are
rather pointless. So yes, please remove this vcc-3v1 one.

What is the story with the other regulator? Is there a PMIC or a power
switch for the SD card? Or is the power supply actually hardwired?

Cheers,
Andre