Subject: Re: [PATCH v2 3/3] arm64: dts: allwinner: A133: add support for Baijie Helper A133 board

From: Alexander Sverdlin <[email-masked]>
Date: Fri, 05 Jun 2026 00:37:40 +0200

Hi Andre,

On Mon, 2026-05-18 at 23:54 +0200, Andre Przywara wrote:
> > > > +&reg_dcdc2 {
> > > > +	regulator-always-on;
> > > > +	regulator-min-microvolt = <500000>;
> > > > +	regulator-max-microvolt = <1300000>;  
> > > 
> > > Should be:
> > >  	regulator-min-microvolt = <900000>;
> > >  	regulator-max-microvolt = <1300000>;  
> > 
> > 0.81..1.2v according to A133 Datasheet Revision 1.1 Jul.14, 2020?
> 
> Do you have the CPU OPPs for this board? Do they slightly
> overclock/over-volt the core? We have seen this for some other boards.
> But you could go with the safer 810mV...1200mV range, and we adjust
> this when needed.

I'm not sure how to interpret this, if it helps, vendor BSP has:

root@HelperA133:~# hexdump -Cv /proc/device-tree/opp_l_table/opp@1512000000/
clock-latency-ns  name              opp-hz            opp-microvolt-b0  opp-microvolt-b1  opp-microvolt-b2  opp-microvolt-b3  
root@HelperA133:~# hexdump -Cv /proc/device-tree/opp_l_table/opp@1512000000/opp-microvolt-b0
00000000  00 12 01 60                                       |...`|
root@HelperA133:~# hexdump -Cv /proc/device-tree/opp_l_table/opp@1512000000/opp-microvolt-b1
00000000  00 11 3e 10 00 11 3e 10  00 11 65 20              |..>...>...e |
root@HelperA133:~# hexdump -Cv /proc/device-tree/opp_l_table/opp@1512000000/opp-microvolt-b2
00000000  00 10 c8 e0                                       |....|
root@HelperA133:~# hexdump -Cv /proc/device-tree/opp_l_table/opp@1512000000/opp-microvolt-b3
00000000  00 10 7a c0                                       |..z.|
root@HelperA133:~# hexdump -Cv /proc/device-tree/opp_l_table/compatible 
00000000  61 6c 6c 77 69 6e 6e 65  72 2c 73 75 6e 35 30 69  |allwinner,sun50i|
00000010  2d 6f 70 65 72 61 74 69  6e 67 2d 70 6f 69 6e 74  |-operating-point|
00000020  73 00                                             |s.|

At least 1512MHz is possible (but datasheet says 1.6GHz, so probably no overclocking yet).

-- 
Alexander Sverdlin.