On Tue, Sep 14, 2021 at 04:52:55PM +0200, Amelie Delaunay wrote:
> This patch adds the description of a new optional property for usbphyc phy
Looks like a lot more than a property.
> sub nodes. st,phy-tuning contains all phy tuning parameters to apply on the
> phy.
>
> Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxxxxxxx>
> ---
> .../bindings/phy/phy-stm32-usbphyc.yaml | 68 +++++++++++++++++++
> 1 file changed, 68 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
> index 3329f1d33a4f..0fa184ea54db 100644
> --- a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
> +++ b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
> @@ -81,6 +81,60 @@ patternProperties:
> properties:
> vbus-supply: true
>
> + st,phy-tuning:
> + $ref: /schemas/types.yaml#/definitions/phandle
Looks like a node to me (type: object). But why is a node needed here?
> + description:
> + It can be necessary to adjust the PHY settings to compensate parasitics, which can be due
> + to USB connector/receptacle, routing, ESD protection component,... Here is the list of
> + all optional parameters to tune the interface of the PHY (HS for High-Speed, FS for Full-
> + Speed, LS for Low-Speed)
> + * st,current-boost, <1> current boosting of 1mA
> + <2> current boosting of 2mA
Use standard unit suffix.
All these need to be a schema, not free form text.
> + * st,no-lsfs-fb-cap, disables the LS/FS feedback capacitor
> + * st,hs-slew-ctrl, slows the HS driver slew rate by 10%
Name the property such that it is self describing. 'slew control'
doesn't say what it does to slew rate.
> + * st,hs-dc-level, <0> = decreases the HS driver DC level by 5 to 7mV
> + <1> = increases the HS driver DC level by 5 to 7mV
> + <2> = increases the HS driver DC level by 10 to 14mV
> + * st,fs-rftime-tuning, enables the FS rise/fall tuning option
> + * st,hs-rftime-reduction, enables the HS rise/fall reduction feature
> + * st,hs-current-trim, controls HS driver current trimming for choke
> + <0> = 18.87 mA target current / nominal + 0%
> + <1> = 19.165 mA target current / nominal + 1.56%
> + <2> = 19.46 mA target current / nominal + 3.12%
> + <3> = 19.755 mA target current / nominal + 4.68%
> + <4> = 20.05 mA target current / nominal + 6.24%
> + <5> = 20.345 mA target current / nominal + 7.8%
> + <6> = 20.64 mA target current / nominal + 9.36%
> + <7> = 20.935 mA target current / nominal + 10.92%
> + <8> = 21.23 mA target current / nominal + 12.48%
> + <9> = 21.525 mA target current / nominal + 14.04%
> + <10> = 21.82 mA target current / nominal + 15.6%
> + <11> = 22.115 mA target current / nominal + 17.16%
> + <12> = 22.458 mA target current / nominal + 19.01%
> + <13> = 22.755 mA target current / nominal + 20.58%
> + <14> = 23.052 mA target current / nominal + 22.16%
> + <15> = 23.348 mA target current / nominal + 23.73%
> + * st,hs-impedance-trim, controls HS driver impedance tuning for choke
> + <0> = no impedance offset
> + <1> = reduces the impedance by 2 ohms
> + <2> = reduces the impedance by 4 ohms
> + <3> = reduces the impedance by 6 ohms
> + * st,squelch-level, adjusts the squelch DC threshold value
> + <0> = no shift in threshold
> + <1> = threshold shift by +7 mV
> + <2> = threshold shift by -5 mV
> + <3> = threshold shift by +14 mV
> + * st,hs-rx-gain-eq, enables the HS Rx gain equalizer
> + * st,hs-rx-offset, adjusts the HS Rx offset
> + <0> = no offset
> + <1> = offset of +5 mV
> + <2> = offset of +10 mV
> + <3> = offset of -5 mV
> + * st,no-hs-ftime-ctrl, disables the HS fall time control of single ended signals
> + during pre-emphasis
> + * st,no-lsfs-sc, disables the short circuit protection in LS/FS driver
> + * st,hs-tx-staggering, enables the basic staggering in HS Tx mode
> +
> allOf:
> - if:
> properties:
> @@ -122,6 +176,18 @@ examples:
> - |
> #include <dt-bindings/clock/stm32mp1-clks.h>
> #include <dt-bindings/reset/stm32mp1-resets.h>
> +
> + usb_phy_tuning: usb-phy-tuning {
> + st,hs-dc-level = <2>;
> + st,fs-rftime-tuning;
> + st,hs-rftime-reduction;
> + st,hs-current-trim = <15>;
> + st,hs-impedance-trim = <1>;
> + st,squelch-level = <3>;
> + st,hs-rx-offset = <2>;
> + st,no-lsfs-sc;
> + };
> +
> usbphyc: usbphyc@5a006000 {
> compatible = "st,stm32mp1-usbphyc";
> reg = <0x5a006000 0x1000>;
> @@ -137,6 +203,7 @@ examples:
> reg = <0>;
> phy-supply = <&vdd_usb>;
> #phy-cells = <0>;
> + st,phy-tuning = <&usb_phy_tuning>;
Just add all the properties here.
> connector {
> compatible = "usb-a-connector";
> vbus-supply = <&vbus_sw>;
> @@ -147,6 +214,7 @@ examples:
> reg = <1>;
> phy-supply = <&vdd_usb>;
> #phy-cells = <1>;
> + st,phy-tuning = <&usb_phy_tuning>;
> };
> };
> ...
> --
> 2.25.1
>
>
