Re: [PATCH v3 net-next 12/14] dt-bindings: net: dsa: ocelot: add ocelot-ext documentation

[Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>]

On 05/10/2022 02:08, Colin Foster wrote:
> Hi Krzysztof,
> 
> On Tue, Oct 04, 2022 at 01:19:33PM +0200, Krzysztof Kozlowski wrote:
>> On 26/09/2022 02:29, Colin Foster wrote:
>>> The ocelot-ext driver is another sub-device of the Ocelot / Felix driver
>>> system, which currently supports the four internal copper phys.
>>>
>>> Signed-off-by: Colin Foster <colin.foster@xxxxxxxxxxxxxxxx>
> ...
>>> +  # Ocelot-ext VSC7512
>>> +  - |
>>> +    spi {
>>> +        soc@0 {
>>
>> soc in spi is a bit confusing.
>>
>> Does it even pass the tests? You have unit address but no reg.
> 
> I omitted those from the documentation. Rob's bot is usually quick to
> alert me when I forgot to run dt_binding_check and something fails
> though. I'll double check, but I thought everything passed.
> 
>>
>>> +            compatible = "mscc,vsc7512";
>>
>>
>>> +            #address-cells = <1>;
>>> +            #size-cells = <1>;
>>> +
>>> +            ethernet-switch@0 {
>>> +                compatible = "mscc,vsc7512-switch";
>>> +                reg = <0 0>;
>>
>> 0 is the address on which soc bus?
> 
> This one Vladimir brought up as well. The MIPS cousin of this chip
> is the VSC7514. They have exactly (or almost exactly) the same hardware,
> except the 7514 has an internal MIPS while the 7512 has an 8051.
> 
> Both chips can be controlled externally via SPI or PCIe. This is adding
> control for the chip via SPI.
> 
> For the 7514, you can see there's an array of 20 register ranges that
> all get mmap'd to 20 different regmaps.
> 
> (Documentation/devicetree/bindings/net/mscc,vsc7514-switch.yaml)
> 
>     switch@1010000 {
>       compatible = "mscc,vsc7514-switch";
>       reg = <0x1010000 0x10000>,
>             <0x1030000 0x10000>,
>             <0x1080000 0x100>,
>             <0x10e0000 0x10000>,
>             <0x11e0000 0x100>,
>             <0x11f0000 0x100>,
>             <0x1200000 0x100>,
>             <0x1210000 0x100>,
>             <0x1220000 0x100>,
>             <0x1230000 0x100>,
>             <0x1240000 0x100>,
>             <0x1250000 0x100>,
>             <0x1260000 0x100>,
>             <0x1270000 0x100>,
>             <0x1280000 0x100>,
>             <0x1800000 0x80000>,
>             <0x1880000 0x10000>,
>             <0x1040000 0x10000>,
>             <0x1050000 0x10000>,
>             <0x1060000 0x10000>,
>             <0x1a0 0x1c4>;
>       reg-names = "sys", "rew", "qs", "ptp", "port0", "port1",
>             "port2", "port3", "port4", "port5", "port6",
>             "port7", "port8", "port9", "port10", "qsys",
>             "ana", "s0", "s1", "s2", "fdma";
> 
> 
> The suggestion was to keep the device trees of the 7512 and 7514 as
> similar as possible, so this will essentially become:
>     switch@71010000 {
>       compatible = "mscc,vsc7512-switch";
>       reg = <0x71010000 0x10000>,
>             <0x71030000 0x10000>,
>       ...

I don't understand how your answer relates to "reg=<0 0>;". How is it
going to become 0x71010000 if there is no other reg/ranges set in parent
nodes. The node has only one IO address, but you say the switch has 20
addresses...

Are we talking about same hardware?

Best regards,
Krzysztof