RE: [PATCH v2 1/3] dt-bindings: arm: renesas: Document Renesas RZ/V2M System Configuration

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> Sent: 14 November 2022 16:51
> To: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>;
> Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>; Geert Uytterhoeven
> <geert+renesas@xxxxxxxxx>
> Cc: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>; Magnus Damm
> <magnus.damm@xxxxxxxxx>; linux-renesas-soc@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; Chris Paterson <Chris.Paterson2@xxxxxxxxxxx>;
> Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx>
> Subject: Re: [PATCH v2 1/3] dt-bindings: arm: renesas: Document Renesas
> RZ/V2M System Configuration
> 
> On 14/11/2022 17:44, Biju Das wrote:
> >>>>> If the hardware manual said this is called "foo-whatever-name" or
> >>>>> "rz85736dfnx2", you would use it as well?
> >>>>>
> >>>>> Node names should be generic.
> >>>
> >>> I got the following feedback from LSI team.
> >>>
> >>> *The reason why we use "configuration" and not "controller" is the
> >>> possibility that users might take it to mean "control" of system
> >>> operation (product operation). This unit determines how the whole
> >>> LSI
> >> configure to operate LSI, so we use "configuration" for this IP name.
> >>>
> >>> As per this it is not a controller. It is a Configuration IP.
> >>>
> >>> What should be generic node name for system configuration IP?
> >>
> >> Then it's closer to chipid and should be in hwinfo?
> >
> > You mean, sys: hwinfo@a3f03000 instead of sys: system-
> configuration@a3f03000 ??
> 
> Rather be put in hwinfo directory. Typical name is "chipid", but I don't know
> if your device is a chipid.

This IP is for sure not a chipid. We can detect SoC version. That is one of the functions provided
by this IP.

> 
> >
> > Also the same IP block is present on rz/v2ma as well?
> >
> > Shall I use the same file renesas,rzv2m-sys.yaml for both r9a09g011-sys and
> r9a09g055-sys?
> >
> >>
> >> Anyway, you wrote in bindings description: "performs system control",
> >> so what can I say?
> >
> > SYS functional description is as follows.
> >
> > The SYS controls the overall configuration of the chip, such as
> 
> Exactly, it controls, so it is a controller... Anyway, do not introduce your
> own names, but use something generic. There is no single reference of
> "system-configuration".

The main functionality of the chip is Bank address configuration,

Bank Address Switching

The SYS has a bank switching register to extend the two higher-order bits of the addresses of the following IP modules
which have only 32-bit (4-GB) address spaces. It makes 4 or more Gbytes of the address space accessible by switching
the bank address.

Target unit 1: DRP-AI, eMMC, SDI0/1, ETHER, PCIe, USB, GRP, VCD
Target unit 2: DMAC

The other control functionalities mentioned in the IP are simple one.

As you said, It is unique IP. Probably in future some other SoC manufactures may come with similar IP for system configuration
like Bank switching. With Bank switching we can switch from 32 bit ->34 bit addresses.

Cheers,
Biju





[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]


  Powered by Linux