Hi Prabhakar,
Thanks for your patch!
On Tue, Apr 23, 2024 at 7:59 PM Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> Add documentation for the pin controller found on the Renesas RZ/V2H(P)
> (R9A09G057) SoC. The RZ/V2H PFC varies slightly compared to the RZ/G2L
> family:
> - Additional bits need to be set during pinmuxing.
> - The GPIO pin count is different.
>
> Hence, a SoC-specific compatible string, 'renesas,r9a09g057-pinctrl', is
> added for the RZ/V2H(P) SoC.
>
> Also, add the 'renesas,output-impedance' property. The drive strength
> setting on RZ/V2H(P) depends on the different power rails coming out from
> the PMIC (connected via I2C). These power rails (required for drive
> strength) can be 1.2V, 1.8V, or 3.3V.
>
> Pins are grouped into 4 groups:
>
> Group 1: Impedance
> - 150/75/38/25 ohms (at 3.3V)
> - 130/65/33/22 ohms (at 1.8V)
>
> Group 2: Impedance
> - 50/40/33/25 ohms (at 1.8V)
>
> Group 3: Impedance
> - 150/75/37.5/25 ohms (at 3.3V)
> - 130/65/33/22 ohms (at 1.8V)
>
> Group 4: Impedance
> - 110/55/30/20 ohms (at 1.8V)
> - 150/75/38/25 ohms (at 1.2V)
>
> The 'renesas,output-impedance' property, as documented, can be
> [0, 1, 2, 3], indicating x1/x2/x3/x4 drive strength.
The documentation says "x1/x2/x4/x6" for all but Group 4 (P20/P21).
Still, the actual values don't seem to match the magnification factors...
> As power rail information may not be available very early in the boot
> process, the 'renesas,output-impedance' property is added instead of
> reusing the 'output-impedance-ohms' property.
>
> Also, allow bias-disable, bias-pull-down and bias-pull-up properties
> as these can be used to configure the pins.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> --- a/Documentation/devicetree/bindings/pinctrl/renesas,rzg2l-pinctrl.yaml
> +++ b/Documentation/devicetree/bindings/pinctrl/renesas,rzg2l-pinctrl.yaml
> @@ -111,6 +116,18 @@ additionalProperties:
> output-high: true
> output-low: true
> line-name: true
> + bias-disable: true
> + bias-pull-down: true
> + bias-pull-up: true
> + renesas,output-impedance:
> + description: |
> + Output impedance for pins on RZ/V2H(P) SoC.
> + 0: Corresponds to x1
> + 1: Corresponds to x2
> + 2: Corresponds to x3
> + 3: Corresponds to x4
Hence I'd drop the multiplication factors, and just say the meaning
of the value is pin-dependent?
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [0, 1, 2, 3]
>
> - type: object
> additionalProperties:
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
