[PATCH 2/3] dt-bindings: phy: phy-stm32-usbphyc: add st, phy-tuning optional property
From: Amelie Delaunay <amelie.delaunay@foss.st.com>
Date: 2021-09-14 14:53:40
Also in:
linux-arm-kernel, linux-devicetree, lkml
Subsystem:
generic phy framework, open firmware and flattened device tree bindings, the rest · Maintainers:
Vinod Koul, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
This patch adds the description of a new optional property for usbphyc phy sub nodes. st,phy-tuning contains all phy tuning parameters to apply on the phy. Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com> --- .../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 + 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 + * st,no-lsfs-fb-cap, disables the LS/FS feedback capacitor + * st,hs-slew-ctrl, slows the HS driver slew rate by 10% + * 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>; 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
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