Re: [PATCH v1] dt-bindings: spi: Add schema for Cadence QSPI Controller driver

"Ramuthevar, Vadivel MuruganX" <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> · Wed, 20 May 2020 18:05:48 +0800

Hi Rob,

  Thank you very much for the review comments...

On 20/5/2020 2:44 am, Rob Herring wrote:
On Tue, May 12, 2020 at 08:49:19AM +0800, Ramuthevar,Vadivel MuruganX wrote:
From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>

Add dt-bindings documentation for Cadence-QSPI controller to support
spi based flash memories.

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
---
  .../devicetree/bindings/mtd/cadence-quadspi.txt    |  67 -----------
  .../devicetree/bindings/spi/cdns,qspi-nor.yaml     | 127 +++++++++++++++++++++
  2 files changed, 127 insertions(+), 67 deletions(-)
  delete mode 100644 Documentation/devicetree/bindings/mtd/cadence-quadspi.txt
  create mode 100644 Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml

diff --git a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt
deleted file mode 100644
index 945be7d5b236..000000000000
--- a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt
+++ /dev/null
@@ -1,67 +0,0 @@
-* Cadence Quad SPI controller
-
-Required properties:
-- compatible : should be one of the following:
-	Generic default - "cdns,qspi-nor".
-	For TI 66AK2G SoC - "ti,k2g-qspi", "cdns,qspi-nor".
-	For TI AM654 SoC  - "ti,am654-ospi", "cdns,qspi-nor".
-- reg : Contains two entries, each of which is a tuple consisting of a
-	physical address and length. The first entry is the address and
-	length of the controller register set. The second entry is the
-	address and length of the QSPI Controller data area.
-- interrupts : Unit interrupt specifier for the controller interrupt.
-- clocks : phandle to the Quad SPI clock.
-- cdns,fifo-depth : Size of the data FIFO in words.
-- cdns,fifo-width : Bus width of the data FIFO in bytes.
-- cdns,trigger-address : 32-bit indirect AHB trigger address.
-
-Optional properties:
-- cdns,is-decoded-cs : Flag to indicate whether decoder is used or not.
-- cdns,rclk-en : 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.
-
-Optional subnodes:
-Subnodes of the Cadence Quad SPI controller are spi slave nodes with additional
-custom properties:
-- cdns,read-delay : Delay for read capture logic, in clock cycles
-- cdns,tshsl-ns : Delay in nanoseconds for the length that the master
-                  mode chip select outputs are de-asserted between
-		  transactions.
-- cdns,tsd2d-ns : Delay in nanoseconds between one chip select being
-                  de-activated and the activation of another.
-- cdns,tchsh-ns : Delay in nanoseconds between last bit of current
-                  transaction and deasserting the device chip select
-		  (qspi_n_ss_out).
-- cdns,tslch-ns : Delay in nanoseconds between setting qspi_n_ss_out low
-                  and first bit transfer.
-- resets	: Must contain an entry for each entry in reset-names.
-		  See ../reset/reset.txt for details.
-- reset-names	: Must include either "qspi" and/or "qspi-ocp".
-
-Example:
-
-	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,is-decoded-cs;
-		cdns,fifo-depth = <128>;
-		cdns,fifo-width = <4>;
-		cdns,trigger-address = <0x00000000>;
-		resets = <&rst QSPI_RESET>, <&rst QSPI_OCP_RESET>;
-		reset-names = "qspi", "qspi-ocp";
-
-		flash0: n25q00@0 {
-			...
-			cdns,read-delay = <4>;
-			cdns,tshsl-ns = <50>;
-			cdns,tsd2d-ns = <50>;
-			cdns,tchsh-ns = <4>;
-			cdns,tslch-ns = <4>;
-		};
-	};
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..28112b38e6a9
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml
@@ -0,0 +1,127 @@
+# 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 QSPI Flash Controller support
+
+maintainers:
+  - Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
+
+allOf:
+  - $ref: "spi-controller.yaml#"
+
+description: |
+  Binding Documentation for Cadence QSPI controller,This controller is
+  present in the Intel LGM, Altera SoCFPGA and TI SoCs and this driver
+  has been tested On Intel's LGM SoC.
+
+properties:
+  compatible:
+     enum:
+       - cdns,qspi-nor
+       - ti,k2g-qspi
+       - ti,am654-ospi
+       - intel,lgm-qspi
+
+  reg:
+    maxItems: 2

Need to define what each entry is.
Noted.

+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  cdns,fifo-depth:
+    description:
+     Depth of hardware FIFOs.

...FIFO in words.
Good catch.

+    allOf:
+      - $ref: "/schemas/types.yaml#/definitions/uint32"
+      - enum: [ 128, 256 ]
+      - default: 128
+
+  cdns,fifo-width:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      4 byte bus width of the data FIFO in bytes.

Constraints? Perhaps:

multipleOf: 4
Noted, will update.

if an enum doesn't work here.

+
+  cdns,trigger-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      32-bit indirect AHB trigger address.
+
+  cdns,rclk-en:
+    type: boolean
+    description: |
+      Flag to indicate that QSPI return clock is used to latch the read data
+      rather than the QSPI clock. Make sure that QSPI return clock is populated
+      on the board before using this property.
+
+# subnode's properties
+patternProperties:
+  "^.*@[0-9a-fa-f]+$":

'a-f' is twice. What's the max number of chip selects? If less than 10,
then '@[0-9]$' is enough. '^.*' can be dropped too.
16 chip select supports.

+    type: object
+    description:
+      flash device uses the subnodes below defined 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
+
+examples:
+  - |
+    spi@ff705000 {
+          compatible = "cdns,qspi-nor";
+          #address-cells = <1>;
+          #size-cells = <0>;
+          reg = <0xff705000 0x1000>,
+                <0xffa00000 0x1000>;

Seems kind of small for a data area if this is like most SPI flash
controllers.yes you are right, following the existing example as it is.

Regards
Vadivel


+          interrupts = <0 151 4>;
+          clocks = <&qspi_clk>;
+          cdns,fifo-depth = <128>;
+          cdns,fifo-width = <4>;
+          cdns,trigger-address = <0x00000000>;
+
+          flash@0 {
+              compatible = "jedec,spi-nor";
+              reg = <0x0>;
+              cdns,read-delay = <4>;
+              cdns,tshsl-ns = <50>;
+              cdns,tsd2d-ns = <50>;
+              cdns,tchsh-ns = <4>;
+              cdns,tslch-ns = <4>;
+          };
+    };
+
--
2.11.0







