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SubjectRe: [PATCH v12 3/3] dt-bindings: mfd: Document Renesas R-Car Gen3 RPC-IF MFD bindings
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On 05/20/2019 10:23 AM, masonccyang@mxic.com.tw wrote:

>>>>> -------------------------------------------------------------->
>>>>>
>>>>> Renesas R-Car Gen3 RPC-IF controller Device Tree Bindings
>>>>> ---------------------------------------------------------
>>>>>
>>>>> RPC-IF supports both SPI NOR and HyperFlash (CFI-compliant flash)
>>>>>
>>>>> Required properties:
>>>>> - compatible: should be an SoC-specific compatible value, followed
>
>>> by
>>>>> "renesas,rcar-gen3-rpc" as a fallback.
>>>>> supported SoC-specific values are:
>>>>> "renesas,r8a77995-rpc" (R-Car D3)
>>>>> - reg: should contain three register areas:
>>>>> first for the base address of RPC-IF registers,
>>>>
>>>> I'd drop "the base address" here.
>>>
>>> okay.
>>>
>>>>> second for the direct mapping read mode and
>>>>> third for the write buffer area.
>>>>> - reg-names: should contain "regs", "dirmap" and "wbuf"
>>>>> - clocks: should contain 1 entries for the module's clock
>>>>> - clock-names: should contain "rpc"
>>>>
>>>> I suspect we'd need the RPC/RPCD2 clocks mentioned as well (not
> sure
>>> yet)...
>>>
>>> Need it ?
>>
>> You seem to call clk_get_rate() on the module clock, I doubt that's
>> correct topologically...

clk_set_rate(), sorry.

>
> I think it's correct but just like Geert mentioned that there is no any
> patch
> in drivers/clk/renesas/r8a77995-cpg-mssr.c adding RPC-related clocks.
>
>
> I patched dt-bindings/clock/r8a77995-cpg-mssr.h for some simple testing
>
> -#define R8A77995_CLK_RPC 29
> -#define R8A77995_CLK_RPCD2 30
> +#define R8A77995_CLK_RPC 31
> +#define R8A77995_CLK_RPCD2 32

Hm, what does this do?

> by clk_prepare_enable() & clk_disable_unprepare() with CPG_MOD 917
> on D3 draak board, it is working fine.

>>>>> - SPI mode:git
>>>>>
>>>>> rpc: rpc-if@ee200000 {
>>>>
>>>> The node names should be generic, based on the device class. And in
>>>> this
>>>> case I'd like to use "spi@ee200000" as otherwise dtc keeps bitching like
>>>> below:
>>>
>>> okay, patch to
>>>
>>> rpc_if: spi@<...>
>>
>> That, or just keep the node label.
>
> okay.
>
>>>>> - HF mode:
>>>>> rpc: rpc-if@ee200000 {
>>>>
>>>> Again, spi@<...>.
>>>
>>> what about rpc_if: hf@<...>
>>
>> Can't change the node name, as it's declared in the .dtsi files, not *.dts
>> ones. And "spi" works for the HF case as well -- no complaints from dtc.
> :-)

Maybe it's possible using the "name" prop, don't know...

> okay,
>
> Patch DTS to
> ===============================================================>
> +Renesas R-Car Gen3 RPC-IF controller Device Tree Bindings
> +---------------------------------------------------------
> +
> +RPC-IF supports both SPI NOR and HyperFlash (CFI-compliant flash)
> +
> +Required properties:
> +- compatible: should be an SoC-specific compatible value, followed by
> + "renesas,rcar-gen3-rpc" as a fallback.
> + supported SoC-specific values are:
> + "renesas,r8a77995-rpc" (R-Car
> D3)
> +- reg: should contain three register areas:
> + first for RPC-IF registers,
> + second for the direct mapping read mode and
> + third for the write buffer area.
> +- reg-names: should contain "regs", "dirmap" and "wbuf"
> +- clocks: should contain 1 entries for the module's clock

1 entry (clock node phandle and specifier).

> +- clock-names: should contain "rpc"
> +- power-domains: should contain system-controller(sysc) for
> power-domain-cell

What's "power-domain-cell"? I know "#power-domain-cells". I'd like this
to be "the power domain node's phandle and specifier".

> +- resets: should contain clock pulse generator(cpg) for reset-cell,

It's "#reset-cells" again. I'd like this to be "the reset node's phandle
and specifier".

> + power-domain-cell and clock-cell

Why mntion clock-cell at all here?

> +- #address-cells: should be 1
> +- #size-cells: should be 0
> +
> +Example:
> +- SPI mode:
> +
> + rpc: spi@ee200000 {
> + compatible = "renesas,r8a77995-rpc",
> "renesas,rcar-gen3-rpc";
> + reg = <0 0xee200000 0 0x200>, <0
> 0x08000000 0 0x4000000>,
> + <0 0xee208000 0 0x100>;
> + reg-names = "regs", "dirmap", "wbuf";
> + clocks = <&cpg CPG_MOD 917>;
> + clock-names = "rpc";
> + power-domains = <&sysc
> R8A77995_PD_ALWAYS_ON>;
> + resets = <&cpg 917>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + flash@0 {
> + compatible =
> "jedec,spi-nor";
> + reg = <0>;
> + spi-max-frequency =
> <40000000>;
> + spi-tx-bus-width = <1>;
> + spi-rx-bus-width = <1>;
> + };
> + };
> +
> +- HF mode:

HyperFlash, please.

> + rpc: spi@ee200000 {
> + compatible = "renesas,r8a77995-rpc",
> "renesas,rcar-gen3-rpc";
> + reg = <0 0xee200000 0 0x200>, <0
> 0x08000000 0 0x4000000>,
> + <0 0xee208000 0 0x100>;
> + reg-names = "regs", "dirmap", "wbuf";
> + clocks = <&cpg CPG_MOD 917>;
> + clock-names = "rpc";
> + power-domains = <&sysc
> R8A77995_PD_ALWAYS_ON>;
> + resets = <&cpg 917>;
> + #address-cells = <1>;
> + #size-cells = <0>;

And I don't think duplicating the same device node is a good idea...

> + flash@0 {
> + compatible =
> "cypress,hyperflash", "cfi-flash";
> + reg = <0>;
> + };
> + };
> ===============================================================<
>
> thanks & best regards,
> Mason
[...]

MBR, Sergei

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