Hello Rob, Mark,

robh@kernel.org wrote on Tue, 21 Sep 2021 14:16:02 -0500:

On Tue, Sep 21, 2021 at 8:43 AM Apurva Nandan [off-list ref] wrote:

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Hi Rob,

On 21/09/21 2:46 am, Rob Herring wrote:  

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On Mon, Sep 20, 2021 at 06:06:51PM +0300, Serge Semin wrote:  

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Hello Apurva

On Mon, Sep 20, 2021 at 07:57:12PM +0530, Apurva Nandan wrote:  

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Convert spi-nand.txt binding to YAML format with an added example.

Signed-off-by: Apurva Nandan <redacted>
---
  .../devicetree/bindings/mtd/spi-nand.txt      |  5 --
  .../devicetree/bindings/mtd/spi-nand.yaml     | 62 +++++++++++++++++++
  2 files changed, 62 insertions(+), 5 deletions(-)
  delete mode 100644 Documentation/devicetree/bindings/mtd/spi-nand.txt
  create mode 100644 Documentation/devicetree/bindings/mtd/spi-nand.yaml  

Thanks for the bindings conversion patch. There are several comments
below. But before addressing them it would be better to also get a
response from Rob.
 

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diff --git a/Documentation/devicetree/bindings/mtd/spi-nand.txt b/Documentation/devicetree/bindings/mtd/spi-nand.txt
deleted file mode 100644
index 8b51f3b6d55c..000000000000
--- a/Documentation/devicetree/bindings/mtd/spi-nand.txt
+++ /dev/null

@@ -1,5 +0,0 @@
-SPI NAND flash
-
-Required properties:
-- compatible: should be "spi-nand"
-- reg: should encode the chip-select line used to access the NAND chip

diff --git a/Documentation/devicetree/bindings/mtd/spi-nand.yaml b/Documentation/devicetree/bindings/mtd/spi-nand.yaml
new file mode 100644
index 000000000000..601beba8d971
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/spi-nand.yaml

@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/spi-nand.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SPI NAND flash
+
+maintainers:
+  - Apurva Nandan <a-nandan@ti.com>
+
+allOf:
+  - $ref: "mtd.yaml#"
+
+properties:
+  compatible:
+    const: spi-nand
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency: true
+  spi-rx-bus-width: true
+  spi-tx-bus-width: true
+  rx-sample-delay-ns: true  

Since it's an SPI-client device there are more than these properties
could be set for it. See the SPI-controller bindings schema:
Documentation/devicetree/bindings/spi/spi-controller.yaml
So there is two possible ways to make it more generic:
1) Detach the spi-client part from the spi-controller.yaml bindings
into a dedicated DT-schema file and refer to that new scheme from
here.  

Yes, as mentioned there's patches doing this. But the above is fine.
There's some value in defining here which properties are valid.  

Yeah right  

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2) Forget about these controller-specific properties and let the
parental SPI-controller bindings parsing them. Of course there must be
at least one of the next properties declared for it to work:
{unevaluatedProperties, additionalProperties}.

It's up to Rob to decided which approach is better though...
 

quoted

+
+  '#address-cells': true
+  '#size-cells': true  

Aren't they always equal to 1?  

No SPI nand devices >4GB?  

Yeah, we have SPI NANDs >4GB, and "'#address-cells': true" allows those
sizes.  

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+
+additionalProperties:
+  type: object  

I'd suggest to elaborate the way the partition sub-nodes looks
like, for instance, the node names, supported compatible names,
labels, etc.  

That should probably all be in mtd.yaml. The question here is whether
partitions are always under a 'partitions' node. Maybe this is new
enough that only the new way has to be supported. Though if mtd.yaml
supported both forms, allowing both all the time is okay IMO.

Rob  

I had added the "partition" node properties in the v1 patch, but as per
the reviews I removed it.
I think we can prefer having them in mtd.yaml if needed, in a separate
patch series.
Do you prefer the mtd.yaml changes as a part of this series or as a
separate patch?

Other than that, I don't find any need for a v3 patch re-roll, do you agree?  

Yeah, I suppose not.

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

And actually, it's Miquel that should apply these 2 rather than Mark.

Yeah, but that's fine for this one, I don't expect conflicts anyway.

Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks,
Miquèl