| Message ID | 20211217093325.30612-11-conor.dooley@microchip.com |
|---|---|
| State | New |
| Headers | show |
| Series | Update the Icicle Kit device tree | expand |
On Fri, Dec 17, 2021 at 09:33:18AM +0000, conor.dooley@microchip.com wrote: > + num-cs: > + description: | > + Number of chip selects used. > + $ref: /schemas/types.yaml#/definitions/uint32 > + minimum: 1 > + maximum: 8 > + default: 8 Why do you need this property in the DT - isn't the number of chip selects in the IP a fixes property?
On 17/12/2021 11:17, Mark Brown wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > On Fri, Dec 17, 2021 at 09:33:18AM +0000, conor.dooley@microchip.com wrote: > > + num-cs: > > + description: | > > + Number of chip selects used. > > + $ref: /schemas/types.yaml#/definitions/uint32 > > + minimum: 1 > > + maximum: 8 > > + default: 8 > > Why do you need this property in the DT - isn't the number of chip > selects in the IP a fixes property? Nope! It's an IP that's intended for use in FPGAs so the number of selects may (and does) vary based on implementation.
On 17/12/2021 11:43, Mark Brown wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > On Fri, Dec 17, 2021 at 11:40:29AM +0000, Conor.Dooley@microchip.com wrote: >> On 17/12/2021 11:17, Mark Brown wrote: >>> Why do you need this property in the DT - isn't the number of chip >>> selects in the IP a fixes property? >> >> Nope! It's an IP that's intended for use in FPGAs so the number of >> selects may (and does) vary based on implementation. > > That doesn't explain why the number is needed in the binding - why do > you need this property in the DT? Took another look at the IP core configuration & I think you're right and that property can be dropped. The register responsible for CS control will not be optimised away even if the CS is not used & the worst outcome is that nothing will happen.
diff --git a/Documentation/devicetree/bindings/spi/microchip,mpfs-spi.yaml b/Documentation/devicetree/bindings/spi/microchip,mpfs-spi.yaml new file mode 100644 index 000000000000..fe257b3384a9 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/microchip,mpfs-spi.yaml @@ -0,0 +1,61 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/spi/microchip,mpfs-spi.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Microchip MPFS {Q,}SPI Controller Device Tree Bindings + +maintainers: + - Conor Dooley <conor.dooley@microchip.com> + +allOf: + - $ref: spi-controller.yaml# + +properties: + compatible: + enum: + - microchip,mpfs-spi + - microchip,mpfs-qspi + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + + clock-names: + maxItems: 1 + + clocks: + maxItems: 1 + + num-cs: + description: | + Number of chip selects used. + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 1 + maximum: 8 + default: 8 + +required: + - compatible + - reg + - interrupts + - clocks + +unevaluatedProperties: false + +examples: + - | + #include "dt-bindings/clock/microchip,mpfs-clock.h" + spi0: spi@20108000 { + compatible = "microchip,mpfs-spi"; + reg = <0x20108000 0x1000>; + clocks = <&clkcfg CLK_SPI0>; + interrupt-parent = <&plic>; + interrupts = <54>; + spi-max-frequency = <25000000>; + num-cs = <8>; + }; +...