Re: [PATCH 4/4] dt-bindings: spi: Convert cadence-quadspi.txt to cadence-quadspi.yaml

Pratyush Yadav
2021-03-29T18:23:48Z

On 27/03/21 12:36PM, Rob Herring wrote:
> On Fri, Mar 26, 2021 at 06:30:34PM +0530, Pratyush Yadav wrote:
> > From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
> >
> > There is no way as of now to have a parent or bus defining properties
> > for child nodes. For now, avoid it in the example to silence warnings on
> > dt_schema_check. We can figure out how to deal with actual dts files
> > later.
> >
> > Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
> > Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> > [p.yadav@ti.com: Fix how compatible is defined, make reset optional, fix
> > minor typos, remove subnode properties in example, update commit
> > message.]
> > ---
> > .../bindings/spi/cadence-quadspi.txt | 68 ---------
> > .../bindings/spi/cdns,qspi-nor.yaml | 143 ++++++++++++++++++
> > 2 files changed, 143 insertions(+), 68 deletions(-)
> > delete mode 100644 Documentation/devicetree/bindings/spi/cadence-quadspi.txt
> > create mode 100644 Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml
>
>
> > diff --git a/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml b/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml
> > new file mode 100644
> > index 000000000000..0e7087cc8bf9
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml
> > @@ -0,0 +1,143 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/spi/cdns,qspi-nor.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Cadence Quad SPI controller
> > +
> > +maintainers:
> > + - Pratyush Yadav <p.yadav@ti.com>
> > +
> > +allOf:
> > + - $ref: spi-controller.yaml#
> > +
> > +properties:
> > + compatible:
> > + oneOf:
> > + - items:
> > + - enum:
> > + - ti,k2g-qspi
> > + - ti,am654-ospi
> > + - intel,lgm-qspi
> > + - const: cdns,qspi-nor
> > + - const: cdns,qspi-nor
> > +
> > + reg:
> > + items:
> > + - description: the controller register set
> > + - description: the controller data area
> > +
> > + interrupts:
> > + maxItems: 1
> > +
> > + clocks:
> > + maxItems: 1
> > +
> > + cdns,fifo-depth:
> > + description:
> > + Size of the data FIFO in words.
> > + $ref: "/schemas/types.yaml#/definitions/uint32"
> > + enum: [ 128, 256 ]
> > + default: 128
> > +
> > + cdns,fifo-width:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Bus width of the data FIFO in bytes.
> > + default: 4
>
> I assume there's some constraints on this?

IIUC this is a matter of how the peripheral is implemented and there are
no clear constraints. Different implementations can use different bus
widths for the SRAM bus but I don't see any mention of minimum or
maximum values. FWIW, all users in the kernel use a 4 byte bus.

>
> With that,
>
> Reviewed-by: Rob Herring <robh@kernel.org>

Thanks.

>
> > +
> > + cdns,trigger-address:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + 32-bit indirect AHB trigger address.
> > +
> > + cdns,is-decoded-cs:
> > + type: boolean
> > + description:
> > + Flag to indicate whether decoder is used to select different chip select
> > + for different memory regions.
> > +
> > + cdns,rclk-en:
> > + type: boolean
> > + description:
> > + Flag to indicate that QSPI return clock is used to latch the read
> > + data rather than the QSPI clock. Make sure that QSPI return clock
> > + is populated on the board before using this property.
> > +
> > + resets:
> > + maxItems: 2
> > +
> > + reset-names:
> > + minItems: 1
> > + maxItems: 2
> > + items:
> > + enum: [ qspi, qspi-ocp ]
> > +
> > +# subnode's properties
> > +patternProperties:
> > + "@[0-9a-f]+$":
> > + type: object
> > + description:
> > + Flash device uses the below defined properties in the subnode.
> > +
> > + properties:
> > + cdns,read-delay:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Delay for read capture logic, in clock cycles.
> > +
> > + cdns,tshsl-ns:
> > + description:
> > + Delay in nanoseconds for the length that the master mode chip select
> > + outputs are de-asserted between transactions.
> > +
> > + cdns,tsd2d-ns:
> > + description:
> > + Delay in nanoseconds between one chip select being de-activated
> > + and the activation of another.
> > +
> > + cdns,tchsh-ns:
> > + description:
> > + Delay in nanoseconds between last bit of current transaction and
> > + deasserting the device chip select (qspi_n_ss_out).
> > +
> > + cdns,tslch-ns:
> > + description:
> > + Delay in nanoseconds between setting qspi_n_ss_out low and
> > + first bit transfer.
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - interrupts
> > + - clocks
> > + - cdns,fifo-depth
> > + - cdns,fifo-width
> > + - cdns,trigger-address
> > + - '#address-cells'
> > + - '#size-cells'
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > + - |
> > + qspi: spi@ff705000 {
> > + compatible = "cdns,qspi-nor";
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + reg = <0xff705000 0x1000>,
> > + <0xffa00000 0x1000>;
> > + interrupts = <0 151 4>;
> > + clocks = <&qspi_clk>;
> > + cdns,fifo-depth = <128>;
> > + cdns,fifo-width = <4>;
> > + cdns,trigger-address = <0x00000000>;
> > + resets = <&rst 0x1>, <&rst 0x2>;
> > + reset-names = "qspi", "qspi-ocp";
> > +
> > + flash@0 {
> > + compatible = "jedec,spi-nor";
> > + reg = <0x0>;
> > + };
> > + };
> > --
> > 2.30.0
> >

--
Regards,
Pratyush Yadav
Texas Instruments Inc.