Document the bindings for STM32 COMBOPHY interface, used to support the PCIe and USB3 stm32mp25 drivers. Following entries can be used to tune caracterisation parameters - st,output-micro-ohms and st,output-vswing-microvolt bindings entries to tune the impedance and voltage swing using discrete simulation results - st,rx-equalizer register to set the internal rx equalizer filter value. Reviewed-by: Rob Herring (Arm) <robh@xxxxxxxxxx> Signed-off-by: Christian Bruel <christian.bruel@xxxxxxxxxxx> --- .../bindings/phy/st,stm32mp25-combophy.yaml | 119 ++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 Documentation/devicetree/bindings/phy/st,stm32mp25-combophy.yaml diff --git a/Documentation/devicetree/bindings/phy/st,stm32mp25-combophy.yaml b/Documentation/devicetree/bindings/phy/st,stm32mp25-combophy.yaml new file mode 100644 index 000000000000..a2e82c0bb56b --- /dev/null +++ b/Documentation/devicetree/bindings/phy/st,stm32mp25-combophy.yaml @@ -0,0 +1,119 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/phy/st,stm32mp25-combophy.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: STMicroelectronics STM32MP25 USB3/PCIe COMBOPHY + +maintainers: + - Christian Bruel <christian.bruel@xxxxxxxxxxx> + +description: + Single lane PHY shared (exclusive) between the USB3 and PCIe controllers. + Supports 5Gbit/s for USB3 and PCIe gen2 or 2.5Gbit/s for PCIe gen1. + +properties: + compatible: + const: st,stm32mp25-combophy + + reg: + maxItems: 1 + + "#phy-cells": + const: 1 + + clocks: + minItems: 2 + items: + - description: apb Bus clock mandatory to access registers. + - description: ker Internal RCC reference clock for USB3 or PCIe + - description: pad Optional on board clock input for PCIe only. Typically an + external 100Mhz oscillator wired on dedicated CLKIN pad. Used as reference + clock input instead of the ker + + clock-names: + minItems: 2 + items: + - const: apb + - const: ker + - const: pad + + resets: + maxItems: 1 + + reset-names: + const: phy + + power-domains: + maxItems: 1 + + wakeup-source: true + + interrupts: + maxItems: 1 + description: interrupt used for wakeup + + access-controllers: + maxItems: 1 + description: Phandle to the rifsc device to check access right. + + st,ssc-on: + $ref: /schemas/types.yaml#/definitions/flag + description: + A property whose presence indicates that the Spread Spectrum Clocking is active. + + st,rx-equalizer: + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 0 + maximum: 7 + default: 2 + description: + A 3 bit value to tune the RX fixed equalizer setting for optimal eye compliance + + st,output-micro-ohms: + minimum: 3999000 + maximum: 6090000 + default: 4968000 + description: + A value property to tune the Single Ended Output Impedance, simulations results + at 25C for a VDDP=0.8V. The hardware accepts discrete values in this range. + + st,output-vswing-microvolt: + minimum: 442000 + maximum: 803000 + default: 803000 + description: + A value property in microvolt to tune the Single Ended Output Voltage Swing to change the + Vlo, Vhi for a VDDP = 0.8V. The hardware accepts discrete values in this range. + +required: + - compatible + - reg + - "#phy-cells" + - clocks + - clock-names + - resets + - reset-names + +additionalProperties: false + +examples: + - | + #include <dt-bindings/clock/st,stm32mp25-rcc.h> + #include <dt-bindings/interrupt-controller/arm-gic.h> + #include <dt-bindings/reset/st,stm32mp25-rcc.h> + + phy@480c0000 { + compatible = "st,stm32mp25-combophy"; + reg = <0x480c0000 0x1000>; + #phy-cells = <1>; + clocks = <&rcc CK_BUS_USB3PCIEPHY>, <&rcc CK_KER_USB3PCIEPHY>; + clock-names = "apb", "ker"; + resets = <&rcc USB3PCIEPHY_R>; + reset-names = "phy"; + access-controllers = <&rifsc 67>; + power-domains = <&CLUSTER_PD>; + wakeup-source; + interrupts-extended = <&exti1 45 IRQ_TYPE_EDGE_FALLING>; + }; -- 2.34.1
