Re: [PATCH 2/3] riscv: dts: spacemit: add 24c02 eeprom on BPI-F3

From: Aurelien Jarno <aurelien@aurel32.net>
To: Yixun Lan <dlan@gentoo.org>
Cc: linux-kernel@vger.kernel.org, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	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 ARCHITECTURE" <linux-riscv@lists.infradead.org>,
	"open list:RISC-V SPACEMIT SoC Support"
	<spacemit@lists.linux.dev>
Subject: Re: [PATCH 2/3] riscv: dts: spacemit: add 24c02 eeprom on BPI-F3
Date: Mon, 22 Sep 2025 06:49:35 +0200	[thread overview]
Message-ID: <aNDVX9IrDbH2w7yJ@aurel32.net> (raw)
In-Reply-To: <20250922032158-GYA1291757@gentoo.org>

Hi,

On 2025-09-22 11:21, Yixun Lan wrote:
> Hi Aurelien,
> 
> On 23:01 Sun 21 Sep     , Aurelien Jarno wrote:
> > The BPI-F3 contains a 24c02 eeprom, that contains among other things the
> > MAC addresses of the two network interfaces. For this reason, mark it as
> > read-only.
> > 
> > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> > ---
> >  arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 11 ++++++++++-
> >  1 file changed, 10 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> > index 3b6e4f52e9aad..574d10fdf9b82 100644
> > --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> > +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> > @@ -115,6 +115,15 @@ &i2c2 {
> >  	pinctrl-0 = <&i2c2_0_cfg>;
> >  	pinctrl-names = "default";
> >  	status = "okay";
> > +
> > +	eeprom@50 {
> > +		compatible = "atmel,24c02";
> > +		reg = <0x50>;
> > +		vcc-supply = <&vcc1v8_sys>;
> > +		pagesize = <16>;
> ..
> > +		read-only;
> so you're sure there is no demand to write data to eeprom?
> (update info at linux env)

It seems to only contains board infos (mac addresses), but if there are 
other use cases, that can indeed be dropped.

> > +		size = <256>;
> > +	};
> >  };
> >  
> >  &i2c8 {
> > @@ -143,7 +152,7 @@ buck2 {
> >  				regulator-always-on;
> >  			};
> >  
> > -			buck3 {
> > +			vcc1v8_sys: buck3 {
> I'm not sure if adding an alias here is a good idea, it occurs buck3
> serve the suppy for many devices, besides, to me it's more proper to
> name it as eeprom_vcc1v8 for the eeprom according to schematics in
> this case..

We need to add a label to be able to reference it for the eeprom 
vcc-supply, but we'll have to also reference it for other devices (e.g.  
emmc, wifi, phys, etc... It tried to choose a common name, ie the right 
most one on the schematics. Another option could be to call it buck3, 
but other name suggestions are welcome.

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                     http://aurel32.net

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