From: Conor Dooley <conor.dooley@microchip.com>
On Polarfire SoC, the Bank 2 and Bank 4 IOs connected to the
Multiprocessor Subsystem (MSS) are controlled by IOMUX_CRs 1 through 6,
which determine what function in routed to them, and
MSSIO_BANK#_IO_CFG_CRs, which determine the configuration of each pin.
Document it, including several custom configuration options that stem
from MSS Configurator options (the MSS Configurator is part of the FPGA
tooling for this device). "ibufmd" unfortunately is not a 1:1 mapping
with an MSS Configurator option, unlike clamp-diode or lockdown, and I
do not know the effect of any bits in the field. I have no been able to
find an explanation for these bits in documentation.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
.../pinctrl/microchip,mpfs-pinctrl-mssio.yaml | 119 ++++++++++++++++++
.../microchip,mpfs-mss-top-sysreg.yaml | 4 +
2 files changed, 123 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pinctrl/microchip,mpfs-pinctrl-mssio.yaml
diff --git a/Documentation/devicetree/bindings/pinctrl/microchip,mpfs-pinctrl-mssio.yaml b/Documentation/devicetree/bindings/pinctrl/microchip,mpfs-pinctrl-mssio.yaml
new file mode 100644
index 000000000000..c8e509ba2f51
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/microchip,mpfs-pinctrl-mssio.yaml
@@ -0,0 +1,119 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/microchip,mpfs-pinctrl-mssio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip Polarfire SoC MSSIO pinctrl
+
+maintainers:
+ - Conor Dooley <conor.dooley@microchip.com>
+
+properties:
+ compatible:
+ oneOf:
+ - const: microchip,mpfs-pinctrl-mssio
+ - items:
+ - const: microchip,pic64gx-pinctrl-mssio
+ - const: microchip,mpfs-pinctrl-mssio
+
+ reg:
+ maxItems: 1
+
+ pinctrl-use-default: true
+
+patternProperties:
+ '-cfg$':
+ type: object
+ additionalProperties: false
+
+ patternProperties:
+ '-pins$':
+ type: object
+ additionalProperties: false
+
+ allOf:
+ - $ref: pincfg-node.yaml#
+ - $ref: pinmux-node.yaml#
+
+ properties:
+ pins:
+ description:
+ The list of IOs that properties in the pincfg node apply to.
+
+ function:
+ description:
+ A string containing the name of the function to mux for these
+ pins. The "reserved" function tristates a pin.
+ enum: [ sd, emmc, qspi, spi, usb, uart, i2c, can, mdio, misc
+ reserved, gpio, fabric-test, tied-low, tied-high, tristate ]
+
+ bias-bus-hold: true
+ bias-disable: true
+ bias-pull-down: true
+ bias-pull-up: true
+ input-schmitt-enable: true
+ low-power-enable: true
+
+ drive-strength:
+ enum: [ 2, 4, 6, 8, 10, 12, 16, 20 ]
+
+ microchip,bank-voltage-microvolt:
+ description:
+ Which bank voltage to use. This cannot differ for pins in a
+ given bank, the whole bank uses the same voltage.
+ enum: [ 1200000, 1500000, 1800000, 2500000, 3300000 ]
+
+ microchip,clamp-diode:
+ $ref: /schemas/types.yaml#/definitions/flag
+ description:
+ Reflects the "Clamp Diode" setting in the MSS Configurator for
+ this pin. This setting controls whether or not input voltage
+ clamping should be enabled.
+
+ microchip,ibufmd:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ default: 0
+ description:
+ Reflects the "IBUFMD" bits in the MSS Configurator output files
+ for this pin.
+
+ required:
+ - pins
+ - function
+ - microchip,bank-voltage-microvolt
+
+ if:
+ properties:
+ microchip,bank-voltage-microvolt:
+ contains:
+ enum: [ 1200000, 1500000, 1800000 ]
+ then:
+ required:
+ - input-schmitt-enable
+
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ pinctrl@204 {
+ compatible = "microchip,mpfs-pinctrl-mssio";
+ reg = <0x204 0x7c>;
+
+ ikrd-spi1-cfg {
+ spi1-pins {
+ pins = <30>, <31>, <32>, <33>;
+ function = "spi";
+ bias-pull-up;
+ drive-strength = <8>;
+ microchip,bank-voltage-microvolt = <3300000>;
+ microchip,ibufmd = <0x1>;
+ };
+ };
+ };
+...
diff --git a/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml b/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml
index 39987f722411..44e4a50c3155 100644
--- a/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml
+++ b/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml
@@ -42,6 +42,10 @@ properties:
type: object
$ref: /schemas/pinctrl/microchip,mpfs-pinctrl-iomux0.yaml
+ pinctrl@204:
+ type: object
+ $ref: /schemas/pinctrl/microchip,mpfs-pinctrl-mssio.yaml
+
required:
- compatible
- reg
--
2.51.0On Thu, Nov 27, 2025 at 10:57:57AM +0000, Conor Dooley wrote:
> From: Conor Dooley <conor.dooley@microchip.com>
>
> On Polarfire SoC, the Bank 2 and Bank 4 IOs connected to the
> Multiprocessor Subsystem (MSS) are controlled by IOMUX_CRs 1 through 6,
> which determine what function in routed to them, and
> MSSIO_BANK#_IO_CFG_CRs, which determine the configuration of each pin.
>
> Document it, including several custom configuration options that stem
> from MSS Configurator options (the MSS Configurator is part of the FPGA
> tooling for this device). "ibufmd" unfortunately is not a 1:1 mapping
> with an MSS Configurator option, unlike clamp-diode or lockdown, and I
> do not know the effect of any bits in the field. I have no been able to
> find an explanation for these bits in documentation.
>
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> ---
> .../pinctrl/microchip,mpfs-pinctrl-mssio.yaml | 119 ++++++++++++++++++
> .../microchip,mpfs-mss-top-sysreg.yaml | 4 +
> 2 files changed, 123 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pinctrl/microchip,mpfs-pinctrl-mssio.yaml
>
> diff --git a/Documentation/devicetree/bindings/pinctrl/microchip,mpfs-pinctrl-mssio.yaml b/Documentation/devicetree/bindings/pinctrl/microchip,mpfs-pinctrl-mssio.yaml
> new file mode 100644
> index 000000000000..c8e509ba2f51
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/microchip,mpfs-pinctrl-mssio.yaml
> @@ -0,0 +1,119 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pinctrl/microchip,mpfs-pinctrl-mssio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Microchip Polarfire SoC MSSIO pinctrl
> +
> +maintainers:
> + - Conor Dooley <conor.dooley@microchip.com>
> +
> +properties:
> + compatible:
> + oneOf:
> + - const: microchip,mpfs-pinctrl-mssio
> + - items:
> + - const: microchip,pic64gx-pinctrl-mssio
> + - const: microchip,mpfs-pinctrl-mssio
> +
> + reg:
> + maxItems: 1
> +
> + pinctrl-use-default: true
> +
> +patternProperties:
> + '-cfg$':
> + type: object
> + additionalProperties: false
> +
> + patternProperties:
> + '-pins$':
> + type: object
> + additionalProperties: false
> +
> + allOf:
> + - $ref: pincfg-node.yaml#
> + - $ref: pinmux-node.yaml#
> +
> + properties:
> + pins:
> + description:
> + The list of IOs that properties in the pincfg node apply to.
pins can be int or string. You need to define which one here.
> +
> + function:
> + description:
> + A string containing the name of the function to mux for these
> + pins. The "reserved" function tristates a pin.
> + enum: [ sd, emmc, qspi, spi, usb, uart, i2c, can, mdio, misc
> + reserved, gpio, fabric-test, tied-low, tied-high, tristate ]
> +
> + bias-bus-hold: true
> + bias-disable: true
> + bias-pull-down: true
> + bias-pull-up: true
> + input-schmitt-enable: true
> + low-power-enable: true
> +
> + drive-strength:
> + enum: [ 2, 4, 6, 8, 10, 12, 16, 20 ]
> +
> + microchip,bank-voltage-microvolt:
> + description:
> + Which bank voltage to use. This cannot differ for pins in a
> + given bank, the whole bank uses the same voltage.
> + enum: [ 1200000, 1500000, 1800000, 2500000, 3300000 ]
"power-source" serves this purpose. It's not well defined as sometimes
it's a register value and sometimes a voltage (in various units).
> +
> + microchip,clamp-diode:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description:
> + Reflects the "Clamp Diode" setting in the MSS Configurator for
> + this pin. This setting controls whether or not input voltage
> + clamping should be enabled.
> +
> + microchip,ibufmd:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + default: 0
> + description:
> + Reflects the "IBUFMD" bits in the MSS Configurator output files
> + for this pin.
> +
> + required:
> + - pins
> + - function
> + - microchip,bank-voltage-microvolt
> +
> + if:
> + properties:
> + microchip,bank-voltage-microvolt:
> + contains:
> + enum: [ 1200000, 1500000, 1800000 ]
> + then:
> + required:
> + - input-schmitt-enable
> +
> +
> +required:
> + - compatible
> + - reg
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + pinctrl@204 {
> + compatible = "microchip,mpfs-pinctrl-mssio";
> + reg = <0x204 0x7c>;
> +
> + ikrd-spi1-cfg {
> + spi1-pins {
> + pins = <30>, <31>, <32>, <33>;
> + function = "spi";
> + bias-pull-up;
> + drive-strength = <8>;
> + microchip,bank-voltage-microvolt = <3300000>;
> + microchip,ibufmd = <0x1>;
> + };
> + };
> + };
> +...
> diff --git a/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml b/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml
> index 39987f722411..44e4a50c3155 100644
> --- a/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml
> +++ b/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml
> @@ -42,6 +42,10 @@ properties:
> type: object
> $ref: /schemas/pinctrl/microchip,mpfs-pinctrl-iomux0.yaml
>
> + pinctrl@204:
> + type: object
> + $ref: /schemas/pinctrl/microchip,mpfs-pinctrl-mssio.yaml
> +
> required:
> - compatible
> - reg
> --
> 2.51.0
>
On Tue, Dec 16, 2025 at 04:16:31PM -0600, Rob Herring wrote: > On Thu, Nov 27, 2025 at 10:57:57AM +0000, Conor Dooley wrote: > > + > > + microchip,bank-voltage-microvolt: > > + description: > > + Which bank voltage to use. This cannot differ for pins in a > > + given bank, the whole bank uses the same voltage. > > + enum: [ 1200000, 1500000, 1800000, 2500000, 3300000 ] > > "power-source" serves this purpose. It's not well defined as sometimes > it's a register value and sometimes a voltage (in various units). I don't recall exactly why I chose not to use that property, because I did know it existed. I *think* it was because the selection was not per pin and I wanted to make it clear - but I should probably just use that property and add the description from above. > > > + > > + microchip,clamp-diode: > > + $ref: /schemas/types.yaml#/definitions/flag > > + description: > > + Reflects the "Clamp Diode" setting in the MSS Configurator for > > + this pin. This setting controls whether or not input voltage > > + clamping should be enabled.
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