[PATCH v3 4/9] ARM: dts: sun7i: cubieboard2: add axp209 regulator nodes

[Chen-Yu Tsai]

On Tue, Jan 13, 2015 at 5:40 PM, Maxime Ripard
<maxime.ripard at free-electrons.com> wrote:
> Hi,
>
> On Mon, Jan 12, 2015 at 05:38:12PM +0800, Chen-Yu Tsai wrote:
>> Hi,
>>
>> On Mon, Jan 12, 2015 at 5:06 PM, Maxime Ripard
>> <maxime.ripard at free-electrons.com> wrote:
>> > Hi Chen-Yu,
>> >
>> > On Mon, Jan 12, 2015 at 12:34:04PM +0800, Chen-Yu Tsai wrote:
>> >> This patch adds the regulator nodes for the axp209 by including
>> >> the axp209 dtsi. As the inputs of these regulators are from the
>> >> axp209's PS output, which is basically just a mux over the 2
>> >> inputs, it is considered to be unregulated. Thus we do not provide
>> >> input supply properties for them.
>> >>
>> >> The regulator names and constraints are based on the board
>> >> schematics and the SoC datasheet.
>> >>
>> >> DCDC2 is used as the cpu power supply. This patch also references
>> >> it from the cpu node.
>> >>
>> >> Also get rid of axp209 properties already set in axp209.dtsi.
>> >>
>> >> Signed-off-by: Chen-Yu Tsai <wens at csie.org>
>> >> ---
>> >>
>> >> changes since v2
>> >>
>> >>     none
>> >>
>> >> changes since v1:
>> >>
>> >>     - Use preprocessor include for axp209.dtsi
>> >>     - Remove incorrectly squashed axp209.dtsi patch
>> >>
>> >> ---
>> >>  arch/arm/boot/dts/sun7i-a20-cubieboard2.dts | 35 +++++++++++++++++++++++++----
>> >>  1 file changed, 31 insertions(+), 4 deletions(-)
>> >>
>> >> diff --git a/arch/arm/boot/dts/sun7i-a20-cubieboard2.dts b/arch/arm/boot/dts/sun7i-a20-cubieboard2.dts
>> >> index 18fc5db9c976..ec1fc2c8b3e3 100644
>> >> --- a/arch/arm/boot/dts/sun7i-a20-cubieboard2.dts
>> >> +++ b/arch/arm/boot/dts/sun7i-a20-cubieboard2.dts
>> >> @@ -88,13 +88,9 @@
>> >>                       status = "okay";
>> >>
>> >>                       axp209: pmic at 34 {
>> >> -                             compatible = "x-powers,axp209";
>> >>                               reg = <0x34>;
>> >>                               interrupt-parent = <&nmi_intc>;
>> >>                               interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
>> >> -
>> >> -                             interrupt-controller;
>> >> -                             #interrupt-cells = <1>;
>> >>                       };
>> >>               };
>> >>
>> >> @@ -145,3 +141,34 @@
>> >>               status = "okay";
>> >>       };
>> >>  };
>> >> +
>> >> +#include "axp209.dtsi"
>> >> +
>> >> +&cpu0 {
>> >> +     cpu-supply = <&reg_dcdc2>;
>> >> +};
>> >> +
>> >> +&reg_dcdc2 {
>> >> +     regulator-always-on;
>> >> +     regulator-min-microvolt = <1000000>;
>> >> +     regulator-max-microvolt = <1450000>;
>> >> +     regulator-name = "vdd-cpu";
>> >> +};
>> >> +
>> >> +&reg_dcdc3 {
>> >> +     regulator-always-on;
>> >> +     regulator-min-microvolt = <1000000>;
>> >> +     regulator-max-microvolt = <1400000>;
>> >> +     regulator-name = "vdd-int-dll";
>> >> +};
>> >> +
>> >> +&reg_ldo1 {
>> >> +     regulator-name = "vdd-rtc";
>> >> +};
>> >> +
>> >> +&reg_ldo2 {
>> >> +     regulator-always-on;
>> >> +     regulator-min-microvolt = <3000000>;
>> >> +     regulator-max-microvolt = <3000000>;
>> >> +     regulator-name = "avcc";
>> >> +};
>> >
>> > How do reg_vcc3v3 and the other reg used in this DT (ahci, USB) fit
>> > into that?
>>
>> The following applies to boards that use AXP209.
>>
>> reg_vcc3v3 or reg_vcc3v0 is an external buck regulator with it's
>> enable pin tied to EXTEN on the AXP. This pin is controllable,
>> but we do not have the driver for it. It is possible that multiple
>> regulators are tied to this pin. I suggest not touching it without
>> the correct schematics.
>>
>> The source for usb and ahci regulators, or reg_vcc5v if you will,
>> is either the unregulated 5v from the power supply or the usb otg
>> port. For the Cubietruck, there's an additional uncontrollable
>> boost regulator that boosts the lipo battery's power up to 5v.
>>
>> On some of the Olimex boards that use higher input voltages, they
>> use an uncontrollable buck regulator to step down the voltage to
>> 5v. The Olinuxino-Micro also has a boost regulator for the battery,
>> tied to EXTEN.
>>
>> The AXP209 simply does not have enough outputs for all the needed
>> voltages.
>
> Hmm, yes, ok. It makes sense.

IPSOUT and the battery stuff should be revisited once we have
a power supply driver.

>> You could probably chain the regulators in the DT via xxx-supply
>> if it helps. But beyond that, it is hard to do anything meaningful
>> at this point. Modeling them as fixed regulators beyond our control
>> is simpler. We also do not have an IPSOUT regulator for the AXP.
>>
>> > Eventually, I think we would be able to remove
>> > sunxi-common-regulators.dtsi, or at least, expose the proper regulator
>> > hierarchy.
>>
>> The USB and SATA regulators are just GPIO enabled switches (MOSFETs)
>> or current limiters. I think these will always exist because of the
>> reference designs. Or do you want to move them back into the board
>> dts files? FWIW, I like it the way it is now. Not that I don't like
>> it to be accurate.
>
> At least providing the right hierarchy at the board level would be
> great. Adding the -supply property to all our fixed regulators
> wouldn't take too much code, and would be enough to model properly the
> regulator trees.

These are all unrelated to axp209. You'd end up with

    vin-supply = <&reg_vcc5v>;

for the usb and sata power regulators. You could put these
in sunxi-common-regulators, and override them for boards
that actually have something controllable.

ChenYu