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Subject[PATCH v2 2/3] dt-bindings: phy: phy-stm32-usbphyc: add optional phy tuning properties
Date
This patch adds the description of new optional phy tuning properties
for usbphyc phy sub nodes.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
Changes in v2:
- st,phy-tuning property removed
- tuning properties are now put directly in each child node
- tuning properties are no more free form text and their name reworked
---
.../bindings/phy/phy-stm32-usbphyc.yaml | 126 ++++++++++++++++++
1 file changed, 126 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
index 3329f1d33a4f..c0f4dff2b8cb 100644
--- a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
+++ b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
@@ -81,6 +81,116 @@ patternProperties:
properties:
vbus-supply: true

+ # 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-milliamp:
+ description: Current boosting in mA
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 1
+ maximum: 2
+
+ st,no-lsfs-fb-cap:
+ description: Disables the LS/FS feedback capacitor
+ type: boolean
+
+ st,decrease-hs-slew-rate:
+ description: Decreases the HS driver slew rate by 10%
+ type: boolean
+
+ st,tune-hs-dc-level:
+ description: Tunes the HS driver DC level
+ - <0> normal level
+ - <1> increases the level by 5 to 7 mV
+ - <2> increases the level by 10 to 14 mV
+ - <3> decreases the level by 5 to 7 mV
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 3
+ default: 0
+
+ st,enable-fs-rftime-tuning:
+ description: Enables the FS rise/fall tuning option
+ type: boolean
+
+ st,enable-hs-rftime-reduction:
+ description: Enables the HS rise/fall reduction feature
+ type: boolean
+
+ st,trim-hs-current:
+ description: Controls HS driver current trimming for choke compensation
+ - <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%
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 15
+ default: 0
+
+ st,trim-hs-impedance:
+ description: Controls HS driver impedance tuning for choke compensation
+ - <0> = no impedance offset
+ - <1> = reduce the impedance by 2 ohms
+ - <2> = reduce the impedance by 4 ohms
+ - <3> = reduce the impedance by 6 ohms
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 3
+ default: 0
+
+ st,tune-squelch-level:
+ description: Tunes 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
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 3
+ default: 0
+
+ st,enable-hs-rx-gain-eq:
+ description: Enables the HS Rx gain equalizer
+ type: boolean
+
+ st,tune-hs-rx-offset:
+ description: Adjusts the HS Rx offset
+ - <0> = no offset
+ - <1> = offset of +5 mV
+ - <2> = offset of +10 mV
+ - <3> = offset of -5 mV
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 3
+ default: 0
+
+ st,no-hs-ftime-ctrl:
+ description: Disables the HS fall time control of single ended signals during pre-emphasis
+ type: boolean
+
+ st,no-lsfs-sc:
+ description: Disables the short circuit protection in LS/FS driver
+ type: boolean
+
+ st,enable-hs-tx-staggering:
+ description: Enables the basic staggering in HS Tx mode
+ type: boolean
+
allOf:
- if:
properties:
@@ -137,6 +247,14 @@ examples:
reg = <0>;
phy-supply = <&vdd_usb>;
#phy-cells = <0>;
+ st,tune-hs-dc-level = <2>;
+ st,enable-fs-rftime-tuning;
+ st,enable-hs-rftime-reduction;
+ st,trim-hs-current = <15>;
+ st,trim-hs-impedance = <1>;
+ st,tune-squelch-level = <3>;
+ st,tune-hs-rx-offset = <2>;
+ st,no-lsfs-sc;
connector {
compatible = "usb-a-connector";
vbus-supply = <&vbus_sw>;
@@ -147,6 +265,14 @@ examples:
reg = <1>;
phy-supply = <&vdd_usb>;
#phy-cells = <1>;
+ st,tune-hs-dc-level = <2>;
+ st,enable-fs-rftime-tuning;
+ st,enable-hs-rftime-reduction;
+ st,trim-hs-current = <15>;
+ st,trim-hs-impedance = <1>;
+ st,tune-squelch-level = <3>;
+ st,tune-hs-rx-offset = <2>;
+ st,no-lsfs-sc;
};
};
...
--
2.25.1
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