Re: [PATCH v2 1/4] riscv: dts: spacemit: k1-bananapi-f3: Add vcc5v0_sys regulator for Banana Pi F3

From: Yixun Lan <dlan@kernel.org>
To: Anand Moon <linux.amoon@gmail.com>
Cc: Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	"open list:RISC-V SPACEMIT SoC Support"
	<linux-riscv@lists.infradead.org>,
	"open list:RISC-V SPACEMIT SoC Support"
	<spacemit@lists.linux.dev>,
	open list <linux-kernel@vger.kernel.org>,
	Han Gao <gaohan@iscas.ac.cn>, Ze Huang <huang.ze@linux.dev>,
	Chukun Pan <amadeus@jmu.edu.cn>
Subject: Re: [PATCH v2 1/4] riscv: dts: spacemit: k1-bananapi-f3: Add vcc5v0_sys regulator for Banana Pi F3
Date: Sat, 9 May 2026 12:18:02 +0000	[thread overview]
Message-ID: <20260509121802-GKB3601591@kernel.org> (raw)
In-Reply-To: <CANAwSgQLhgC6puNy2dkMjL=hd+yTYizBBFykd63KJDbw48219w@mail.gmail.com>

Hi Anand,

On 13:06 Fri 08 May     , Anand Moon wrote:
> Hi Yixun,
> 
> Thanks for your review comments.
> 
> On Thu, 7 May 2026 at 08:15, Yixun Lan <dlan@kernel.org> wrote:
> >
> > Hi Anand,
> >
> > On 10:48 Sat 02 May     , Anand Moon wrote:
> > > Define the system 5V fixed regulator (vcc5v0_sys) supplied by the
> > > DC input. As per the schematics, vcc5v0_sys is the input power source
> > > for the VCC5V0_HUB and 5V_VBUS reglators. Update these regulators
> > > to correctly reference vcc5v0_sys as their parent (vin-supply).
> > >
> > > Cc: Han Gao <gaohan@iscas.ac.cn>
> > > Cc: Ze Huang <huang.ze@linux.dev>
> > > Cc: Chukun Pan <amadeus@jmu.edu.cn>
> > > Signed-off-by: Anand Moon <linux.amoon@gmail.com>
> > > ---
> > >  arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 12 ++++++++++++
> > >  1 file changed, 12 insertions(+)
> > >
> > > diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> > > index 5790d927b93d..9727ecdd9f6b 100644
> > > --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> > > +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> > > @@ -50,6 +50,16 @@ reg_dc_in: regulator-dc-in-12v {
> > >               regulator-always-on;
> > >       };
> > >
> > > +     reg_vcc5v0_sys: regulator-vcc5v0-sys {
> > This will fall into the catogery of "non-controllable & serve no devices"
> > see similar comment for 'reg_dc_in' which raised by Krzysztof
> >
> > https://lore.kernel.org/all/6530526f-59ca-4753-a068-46c62a1a1fed@kernel.org/
> >
> > or should I ask, what's the real problem if regulator has no vin-supply?
> 
> If the device tree is not configured with the correct power source it
> will affect performance.
> 
Please elaborate, or provide enough evidence to prove this, because the
conclusion you gave here contradicts with what Krzysztof pointed out

> > Any probe failure or something bad happen? (besides /sys/../regulator_summay)
> 
> Not really; the regulator summary just confirms the PMIC used the
> correct power source.
> with te device ip blocks.
> 
then I see it's unnecessary to add this

> Bananapi F3 schematics.
> [1] https://drive.google.com/file/d/19iLJ5xnCB_oK8VeQjkPGjzAn39WYyylv/view
> (page 24)
> 
> Please check the shematics VCC5V0_SYS page 4
> VCC5V0_SYS->USB_VCC5V0->HDMI_VCC5V0->FAN_VCC5V0->VCC3V3_SYS
> 
> Please check the shematics VCC5V0_SYS page 24
> VCC5V0_SYS input for VCC5V0_HUB and 5V_VBUS give the USB hub,
> which is enabled by USB3_PWREN (gpio pin)>
> 
> Plese check power tree page 4
> USBVBUS->SY8386J UXXX -> PCIE_VCC3V3 for pcie vin source
> 
> So, this series tries to fix the vin source for USB 3.0 and PCIe nodes.
> 
This is not what I ask..

-- 
Yixun Lan (dlan)