On 27/03/21 12:36PM, Rob Herring wrote:

On Fri, Mar 26, 2021 at 06:30:34PM +0530, Pratyush Yadav wrote:

quoted

From: Ramuthevar Vadivel Murugan <redacted>

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 <redacted>
Signed-off-by: Pratyush Yadav <redacted>
[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

quoted

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.

quoted

+
+  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.