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@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
+ 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
