diff mbox series

arm64: dts: rockchip: add EEPROM node for NanoPi R4S

Message ID 20210607081727.4723-1-cnsztl@gmail.com (mailing list archive)
State New
Headers show
Series arm64: dts: rockchip: add EEPROM node for NanoPi R4S | expand

Commit Message

Tianling Shen June 7, 2021, 8:17 a.m. UTC
NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
stores the MAC address.

Signed-off-by: Tianling Shen <cnsztl@gmail.com>
---
 arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Chen-Yu Tsai June 7, 2021, 8:35 a.m. UTC | #1
Hi,

On Mon, Jun 7, 2021 at 4:19 PM Tianling Shen <cnsztl@gmail.com> wrote:
>
> NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
> stores the MAC address.
>
> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
> ---
>  arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> index cef4d18b599d..4a82f50a07c5 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> @@ -68,6 +68,15 @@
>         status = "disabled";
>  };
>
> +&i2c2 {
> +       eeprom@51 {
> +               compatible = "microchip,24c02", "atmel,24c02";

The actual part number is Microchip 24AA025E48, but I don't think
the way this device splits its storage area is easy to support
without additional modifications to the driver.

> +               reg = <0x51>;
> +               pagesize = <16>;
> +               read-only; /* This holds our MAC */

Please also add the size, as well as a cell defining the offset
and length to the MAC address. The gmac node can then reference
this with:

    nvmem-cells = <&mac_address>;
    nvmem-cells-names = "mac-address";

which will actually pick up the MAC address.


Regards
ChenYu

> +       };
> +};
> +
>  &i2c4 {
>         status = "disabled";
>  };
> --
> 2.17.1
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Johan Jonker June 7, 2021, 9:14 a.m. UTC | #2
Hi Tianling,

On 6/7/21 10:17 AM, Tianling Shen wrote:
> NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
> stores the MAC address.
> 
> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
> ---
>  arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> index cef4d18b599d..4a82f50a07c5 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> @@ -68,6 +68,15 @@
>  	status = "disabled";
>  };
>  
> +&i2c2 {
> +	eeprom@51 {
> +		compatible = "microchip,24c02", "atmel,24c02";
> +		reg = <0x51>;
> +		pagesize = <16>;

> +		read-only; /* This holds our MAC */

The mainline dts files should be generic I think.
Any comment about "use", partitions or write ability should be avoided.
It's up the user.

Johan

> +	};
> +};
> +
>  &i2c4 {
>  	status = "disabled";
>  };
>
Chen-Yu Tsai June 7, 2021, 9:40 a.m. UTC | #3
On Mon, Jun 7, 2021 at 5:31 PM Johan Jonker <jbx6244@gmail.com> wrote:
>
> Hi Tianling,
>
> On 6/7/21 10:17 AM, Tianling Shen wrote:
> > NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
> > stores the MAC address.
> >
> > Signed-off-by: Tianling Shen <cnsztl@gmail.com>
> > ---
> >  arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> > index cef4d18b599d..4a82f50a07c5 100644
> > --- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> > +++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> > @@ -68,6 +68,15 @@
> >       status = "disabled";
> >  };
> >
> > +&i2c2 {
> > +     eeprom@51 {
> > +             compatible = "microchip,24c02", "atmel,24c02";
> > +             reg = <0x51>;
> > +             pagesize = <16>;
>
> > +             read-only; /* This holds our MAC */
>
> The mainline dts files should be generic I think.
> Any comment about "use", partitions or write ability should be avoided.
> It's up the user.

Per the datasheet for this specific EEPROM, the latter half (128 bytes)
is read-only in hardware by design though.

ChenYu
Johan Jonker June 7, 2021, 10:26 a.m. UTC | #4
Hi Chen-Yu,

On 6/7/21 11:40 AM, Chen-Yu Tsai wrote:
> On Mon, Jun 7, 2021 at 5:31 PM Johan Jonker <jbx6244@gmail.com> wrote:
>>
>> Hi Tianling,
>>
>> On 6/7/21 10:17 AM, Tianling Shen wrote:
>>> NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
>>> stores the MAC address.
>>>
>>> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
>>> ---
>>>  arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
>>>  1 file changed, 9 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
>>> index cef4d18b599d..4a82f50a07c5 100644
>>> --- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
>>> +++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
>>> @@ -68,6 +68,15 @@
>>>       status = "disabled";
>>>  };
>>>
>>> +&i2c2 {
>>> +     eeprom@51 {
>>> +             compatible = "microchip,24c02", "atmel,24c02";
>>> +             reg = <0x51>;
>>> +             pagesize = <16>;
>>
>>> +             read-only; /* This holds our MAC */
>>
>> The mainline dts files should be generic I think.
>> Any comment about "use", partitions or write ability should be avoided.
>> It's up the user.
> 

> Per the datasheet for this specific EEPROM, the latter half (128 bytes)
> is read-only in hardware by design though.

The 24AA02XEXX is programmed at the factory with a
globally unique node address stored in the upper half
of the array and permanently write-protected. The
remaining 1,024 bits are available for application use.

Just a question...

    nvmem-cells = <&mac_address>;
    nvmem-cells-names = "mac-address";

Which part does this point to?

Can we use the lower part to store/rewrite this too?

===

From at24.yaml:

            items:
              - pattern:
"^(atmel|catalyst|microchip|nxp|ramtron|renesas|rohm|st),(24(c|cs|lc|mac)[0-9]+|spd)$"
              - pattern: "^atmel,(24(c|cs|mac)[0-9]+|spd)$"

How does Microchip 24AA025E48 fit the regex?
What compatible would you advise?

===

Johan

> 
> ChenYu
>
Chen-Yu Tsai June 7, 2021, 11:20 a.m. UTC | #5
Hi,

On Mon, Jun 7, 2021 at 6:26 PM Johan Jonker <jbx6244@gmail.com> wrote:
>
> Hi Chen-Yu,
>
> On 6/7/21 11:40 AM, Chen-Yu Tsai wrote:
> > On Mon, Jun 7, 2021 at 5:31 PM Johan Jonker <jbx6244@gmail.com> wrote:
> >>
> >> Hi Tianling,
> >>
> >> On 6/7/21 10:17 AM, Tianling Shen wrote:
> >>> NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
> >>> stores the MAC address.
> >>>
> >>> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
> >>> ---
> >>>  arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
> >>>  1 file changed, 9 insertions(+)
> >>>
> >>> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> >>> index cef4d18b599d..4a82f50a07c5 100644
> >>> --- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> >>> +++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> >>> @@ -68,6 +68,15 @@
> >>>       status = "disabled";
> >>>  };
> >>>
> >>> +&i2c2 {
> >>> +     eeprom@51 {
> >>> +             compatible = "microchip,24c02", "atmel,24c02";
> >>> +             reg = <0x51>;
> >>> +             pagesize = <16>;
> >>
> >>> +             read-only; /* This holds our MAC */
> >>
> >> The mainline dts files should be generic I think.
> >> Any comment about "use", partitions or write ability should be avoided.
> >> It's up the user.
> >
>
> > Per the datasheet for this specific EEPROM, the latter half (128 bytes)
> > is read-only in hardware by design though.
>
> The 24AA02XEXX is programmed at the factory with a
> globally unique node address stored in the upper half
> of the array and permanently write-protected. The
> remaining 1,024 bits are available for application use.
>
> Just a question...
>
>     nvmem-cells = <&mac_address>;
>     nvmem-cells-names = "mac-address";
>
> Which part does this point to?

In the eeprom node:

    mac_address: mac-address@fa {
            reg = <0xfa 0x6>;
    };

> Can we use the lower part to store/rewrite this too?

If you don't set it to read only, then you could rewrite the lower
portion. Writes to the upper portion would be ignored.

> ===
>
> From at24.yaml:
>
>             items:
>               - pattern:
> "^(atmel|catalyst|microchip|nxp|ramtron|renesas|rohm|st),(24(c|cs|lc|mac)[0-9]+|spd)$"
>               - pattern: "^atmel,(24(c|cs|mac)[0-9]+|spd)$"
>
> How does Microchip 24AA025E48 fit the regex?
> What compatible would you advise?

New regex: "^microchip,24aa025?e(48|64)$"


All that was what I had around in my tree.

ChenYu
Tianling Shen June 7, 2021, 12:48 p.m. UTC | #6
Hi Chen-Yu,

On Mon, Jun 7, 2021 at 4:36 PM Chen-Yu Tsai <wens@kernel.org> wrote:
>
> Hi,
>
> On Mon, Jun 7, 2021 at 4:19 PM Tianling Shen <cnsztl@gmail.com> wrote:
> >
> > NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
> > stores the MAC address.
> >
> > Signed-off-by: Tianling Shen <cnsztl@gmail.com>
> > ---
> >  arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> > index cef4d18b599d..4a82f50a07c5 100644
> > --- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> > +++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> > @@ -68,6 +68,15 @@
> >         status = "disabled";
> >  };
> >
> > +&i2c2 {
> > +       eeprom@51 {
> > +               compatible = "microchip,24c02", "atmel,24c02";
>
> The actual part number is Microchip 24AA025E48, but I don't think
> the way this device splits its storage area is easy to support
> without additional modifications to the driver.
>

On the face of it, it seems to work fine, and I can read the data correctly.
(built with at24 eeprom driver)

Thanks,
Tianling.

> > +               reg = <0x51>;
> > +               pagesize = <16>;
> > +               read-only; /* This holds our MAC */
>
> Please also add the size, as well as a cell defining the offset
> and length to the MAC address. The gmac node can then reference
> this with:
>
>     nvmem-cells = <&mac_address>;
>     nvmem-cells-names = "mac-address";
>
> which will actually pick up the MAC address.
>
>
> Regards
> ChenYu
>
> > +       };
> > +};
> > +
> >  &i2c4 {
> >         status = "disabled";
> >  };
> > --
> > 2.17.1
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Tianling Shen June 7, 2021, 4:01 p.m. UTC | #7
Hi Johan,

On Mon, Jun 7, 2021 at 6:26 PM Johan Jonker <jbx6244@gmail.com> wrote:
>
> Hi Chen-Yu,
>
> On 6/7/21 11:40 AM, Chen-Yu Tsai wrote:
> > On Mon, Jun 7, 2021 at 5:31 PM Johan Jonker <jbx6244@gmail.com> wrote:
> >>
> >> Hi Tianling,
> >>
> >> On 6/7/21 10:17 AM, Tianling Shen wrote:
> >>> NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
> >>> stores the MAC address.
> >>>
> >>> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
> >>> ---
> >>>  arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
> >>>  1 file changed, 9 insertions(+)
> >>>
> >>> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> >>> index cef4d18b599d..4a82f50a07c5 100644
> >>> --- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> >>> +++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> >>> @@ -68,6 +68,15 @@
> >>>       status = "disabled";
> >>>  };
> >>>
> >>> +&i2c2 {
> >>> +     eeprom@51 {
> >>> +             compatible = "microchip,24c02", "atmel,24c02";
> >>> +             reg = <0x51>;
> >>> +             pagesize = <16>;
> >>
> >>> +             read-only; /* This holds our MAC */
> >>
> >> The mainline dts files should be generic I think.
> >> Any comment about "use", partitions or write ability should be avoided.
> >> It's up the user.
> >
>
> > Per the datasheet for this specific EEPROM, the latter half (128 bytes)
> > is read-only in hardware by design though.
>
> The 24AA02XEXX is programmed at the factory with a
> globally unique node address stored in the upper half
> of the array and permanently write-protected. The
> remaining 1,024 bits are available for application use.
>

In my opinion, as this contains data programmed by the factory, would
it be okay to keep it read-only?

> Just a question...
>
>     nvmem-cells = <&mac_address>;
>     nvmem-cells-names = "mac-address";
>
> Which part does this point to?
>
> Can we use the lower part to store/rewrite this too?
>
> ===
>
> From at24.yaml:
>
>             items:
>               - pattern:
> "^(atmel|catalyst|microchip|nxp|ramtron|renesas|rohm|st),(24(c|cs|lc|mac)[0-9]+|spd)$"
>               - pattern: "^atmel,(24(c|cs|mac)[0-9]+|spd)$"
>
> How does Microchip 24AA025E48 fit the regex?
> What compatible would you advise?

It seems that 24AA025E48 is a variant of 24MAC402 [1], and
`atmel,24c02` will be okay in this case.
1. https://lkml.org/lkml/2018/1/24/494

Thanks,
Tianling.

>
> ===
>
> Johan
>
> >
> > ChenYu
> >
Johan Jonker June 7, 2021, 5:04 p.m. UTC | #8
On 6/7/21 6:01 PM, Tianling Shen wrote:
> Hi Johan,
> 
> On Mon, Jun 7, 2021 at 6:26 PM Johan Jonker <jbx6244@gmail.com> wrote:
>>
>> Hi Chen-Yu,
>>
>> On 6/7/21 11:40 AM, Chen-Yu Tsai wrote:
>>> On Mon, Jun 7, 2021 at 5:31 PM Johan Jonker <jbx6244@gmail.com> wrote:
>>>>
>>>> Hi Tianling,
>>>>
>>>> On 6/7/21 10:17 AM, Tianling Shen wrote:
>>>>> NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
>>>>> stores the MAC address.
>>>>>
>>>>> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
>>>>> ---
>>>>>  arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
>>>>>  1 file changed, 9 insertions(+)
>>>>>
>>>>> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
>>>>> index cef4d18b599d..4a82f50a07c5 100644
>>>>> --- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
>>>>> +++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
>>>>> @@ -68,6 +68,15 @@
>>>>>       status = "disabled";
>>>>>  };
>>>>>
>>>>> +&i2c2 {
>>>>> +     eeprom@51 {
>>>>> +             compatible = "microchip,24c02", "atmel,24c02";
>>>>> +             reg = <0x51>;
>>>>> +             pagesize = <16>;
>>>>
>>>>> +             read-only; /* This holds our MAC */
>>>>
>>>> The mainline dts files should be generic I think.
>>>> Any comment about "use", partitions or write ability should be avoided.
>>>> It's up the user.
>>>
>>
>>> Per the datasheet for this specific EEPROM, the latter half (128 bytes)
>>> is read-only in hardware by design though.
>>
>> The 24AA02XEXX is programmed at the factory with a
>> globally unique node address stored in the upper half
>> of the array and permanently write-protected. The
>> remaining 1,024 bits are available for application use.
>>
> 

> In my opinion, as this contains data programmed by the factory, would
> it be okay to keep it read-only?

This chip is not completely read-only.
There might be users that like to try some other mac_address or store
something else in that lower part. Is this then still possible?
Generic DT describes hardware independent from what Linux drivers or
other OS are capable off.
This factory mac_addres is permanently write-protected, so no need to
keep the rest read-only.

     nvmem-cells = <&new_mac_address_in_lower_part>;
     nvmem-cells-names = "mac-address";

> 
>> Just a question...
>>
>>     nvmem-cells = <&mac_address>;
>>     nvmem-cells-names = "mac-address";
>>
>> Which part does this point to?
>>
>> Can we use the lower part to store/rewrite this too?
>>
>> ===
>>
>> From at24.yaml:
>>
>>             items:
>>               - pattern:
>> "^(atmel|catalyst|microchip|nxp|ramtron|renesas|rohm|st),(24(c|cs|lc|mac)[0-9]+|spd)$"
>>               - pattern: "^atmel,(24(c|cs|mac)[0-9]+|spd)$"
>>
>> How does Microchip 24AA025E48 fit the regex?
>> What compatible would you advise?
> 
> It seems that 24AA025E48 is a variant of 24MAC402 [1], and
> `atmel,24c02` will be okay in this case.
> 1. https://lkml.org/lkml/2018/1/24/494

Ask Heiko. ;)

As long as it does not generate more notifications then we already have.

> 
> Thanks,
> Tianling.
> 
>>
>> ===
>>
>> Johan
>>
>>>
>>> ChenYu
>>>
Chen-Yu Tsai June 7, 2021, 5:08 p.m. UTC | #9
On Tue, Jun 8, 2021 at 1:04 AM Johan Jonker <jbx6244@gmail.com> wrote:
>
>
>
> On 6/7/21 6:01 PM, Tianling Shen wrote:
> > Hi Johan,
> >
> > On Mon, Jun 7, 2021 at 6:26 PM Johan Jonker <jbx6244@gmail.com> wrote:
> >>
> >> Hi Chen-Yu,
> >>
> >> On 6/7/21 11:40 AM, Chen-Yu Tsai wrote:
> >>> On Mon, Jun 7, 2021 at 5:31 PM Johan Jonker <jbx6244@gmail.com> wrote:
> >>>>
> >>>> Hi Tianling,
> >>>>
> >>>> On 6/7/21 10:17 AM, Tianling Shen wrote:
> >>>>> NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
> >>>>> stores the MAC address.
> >>>>>
> >>>>> Signed-off-by: Tianling Shen <cnsztl@gmail.com>
> >>>>> ---
> >>>>>  arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 9 +++++++++
> >>>>>  1 file changed, 9 insertions(+)
> >>>>>
> >>>>> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> >>>>> index cef4d18b599d..4a82f50a07c5 100644
> >>>>> --- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> >>>>> +++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
> >>>>> @@ -68,6 +68,15 @@
> >>>>>       status = "disabled";
> >>>>>  };
> >>>>>
> >>>>> +&i2c2 {
> >>>>> +     eeprom@51 {
> >>>>> +             compatible = "microchip,24c02", "atmel,24c02";
> >>>>> +             reg = <0x51>;
> >>>>> +             pagesize = <16>;
> >>>>
> >>>>> +             read-only; /* This holds our MAC */
> >>>>
> >>>> The mainline dts files should be generic I think.
> >>>> Any comment about "use", partitions or write ability should be avoided.
> >>>> It's up the user.
> >>>
> >>
> >>> Per the datasheet for this specific EEPROM, the latter half (128 bytes)
> >>> is read-only in hardware by design though.
> >>
> >> The 24AA02XEXX is programmed at the factory with a
> >> globally unique node address stored in the upper half
> >> of the array and permanently write-protected. The
> >> remaining 1,024 bits are available for application use.
> >>
> >
>
> > In my opinion, as this contains data programmed by the factory, would
> > it be okay to keep it read-only?
>
> This chip is not completely read-only.
> There might be users that like to try some other mac_address or store
> something else in that lower part. Is this then still possible?
> Generic DT describes hardware independent from what Linux drivers or
> other OS are capable off.
> This factory mac_addres is permanently write-protected, so no need to
> keep the rest read-only.
>
>      nvmem-cells = <&new_mac_address_in_lower_part>;
>      nvmem-cells-names = "mac-address";
>
> >
> >> Just a question...
> >>
> >>     nvmem-cells = <&mac_address>;
> >>     nvmem-cells-names = "mac-address";
> >>
> >> Which part does this point to?
> >>
> >> Can we use the lower part to store/rewrite this too?
> >>
> >> ===
> >>
> >> From at24.yaml:
> >>
> >>             items:
> >>               - pattern:
> >> "^(atmel|catalyst|microchip|nxp|ramtron|renesas|rohm|st),(24(c|cs|lc|mac)[0-9]+|spd)$"
> >>               - pattern: "^atmel,(24(c|cs|mac)[0-9]+|spd)$"
> >>
> >> How does Microchip 24AA025E48 fit the regex?
> >> What compatible would you advise?
> >
> > It seems that 24AA025E48 is a variant of 24MAC402 [1], and
> > `atmel,24c02` will be okay in this case.
> > 1. https://lkml.org/lkml/2018/1/24/494
>
> Ask Heiko. ;)
>
> As long as it does not generate more notifications then we already have.

I think having a part specific compatible would be better. That way if
someone wanted to implement read-only "feedback" to users for the second
half they could.

ChenYu

> >
> > Thanks,
> > Tianling.
> >
> >>
> >> ===
> >>
> >> Johan
> >>
> >>>
> >>> ChenYu
> >>>
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
index cef4d18b599d..4a82f50a07c5 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
@@ -68,6 +68,15 @@ 
 	status = "disabled";
 };
 
+&i2c2 {
+	eeprom@51 {
+		compatible = "microchip,24c02", "atmel,24c02";
+		reg = <0x51>;
+		pagesize = <16>;
+		read-only; /* This holds our MAC */
+	};
+};
+
 &i2c4 {
 	status = "disabled";
 };