Re: [PATCH v9 02/15] dt-bindings: mmc: cdns: Add AMD Pensando Elba SoC

From: Brad Larson <blarson@amd.com>
To: <krzysztof.kozlowski@linaro.org>
Cc: <adrian.hunter@intel.com>, <alcooperx@gmail.com>,
	<andy.shevchenko@gmail.com>, <arnd@arndb.de>, <blarson@amd.com>,
	<brad@pensando.io>, <brendan.higgins@linux.dev>,
	<briannorris@chromium.org>, <brijeshkumar.singh@amd.com>,
	<broonie@kernel.org>, <catalin.marinas@arm.com>,
	<davidgow@google.com>, <devicetree@vger.kernel.org>,
	<fancer.lancer@gmail.com>, <gerg@linux-m68k.org>,
	<gsomlo@gmail.com>, <krzk@kernel.org>,
	<krzysztof.kozlowski+dt@linaro.org>, <lee.jones@linaro.org>,
	<lee@kernel.org>, <linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <linux-mmc@vger.kernel.org>,
	<linux-spi@vger.kernel.org>, <p.yadav@ti.com>,
	<p.zabel@pengutronix.de>, <piotrs@cadence.com>,
	<rdunlap@infradead.org>, <robh+dt@kernel.org>,
	<samuel@sholland.org>, <skhan@linuxfoundation.org>,
	<suravee.suthikulpanit@amd.com>, <thomas.lendacky@amd.com>,
	<tonyhuang.sunplus@gmail.com>, <ulf.hansson@linaro.org>,
	<vaishnav.a@ti.com>, <will@kernel.org>,
	<yamada.masahiro@socionext.com>
Subject: Re: [PATCH v9 02/15] dt-bindings: mmc: cdns: Add AMD Pensando Elba SoC
Date: Fri, 20 Jan 2023 17:10:04 -0800	[thread overview]
Message-ID: <20230121011004.38654-1-blarson@amd.com> (raw)
In-Reply-To: <f85cdf27-7ea0-14a8-10b0-7a9ac137a040@linaro.org>

On 19/01/2023 7:47 UTC, Krzysztof Kozlowski wrote:
>On 19/01/2023 04:51, Brad Larson wrote:
>> AMD Pensando Elba ARM 64-bit SoC is integrated with this IP and
>> explicitly controls byte-lane enables.
>> 
...
>> diff --git a/Documentation/devicetree/bindings/mmc/cdns,sdhci.yaml b/Documentation/devicetree/bindings/mmc/cdns,sdhci.yaml
>> index 8b1a0fdcb5e3..f7dd6f990f96 100644
>> --- a/Documentation/devicetree/bindings/mmc/cdns,sdhci.yaml
>> +++ b/Documentation/devicetree/bindings/mmc/cdns,sdhci.yaml
>> @@ -16,12 +16,14 @@ properties:
>>    compatible:
>>      items:
>>        - enum:
>> +          - amd,pensando-elba-sd4hc
>>            - microchip,mpfs-sd4hc
>>            - socionext,uniphier-sd4hc
>>        - const: cdns,sd4hc
>>  
>>    reg:
>> -    maxItems: 1
>> +    minItems: 1
>> +    maxItems: 2
>>  
>>    interrupts:
>>      maxItems: 1
>> @@ -111,12 +113,36 @@ properties:
>>      minimum: 0
>>      maximum: 0x7f
>>  
>> +  reset-names:
>> +    items:
>> +      - const: hw
>> +
>> +  resets:
>> +    description:
>> +      optional. phandle to the system reset controller with line index
>
>Drop "optional"
>Drop "phandle to the" and rephrase it to describe physical reset line.
>Don't describe here DT syntax (phandle) but the hardware. What is
>expected to be here?

Done, see the resulting diff below for full context.  The missing
'contains' was the bug.

>> +      for mmc hw reset line if exists.
>> +    maxItems: 1
>> +
>>  required:
>>    - compatible
>>    - reg
>>    - interrupts
>>    - clocks
>>  
>> +if:
>
>Move the allO from the top here and put it under it. Saves indentation soon.

Yes.

>> +  properties:
>> +    compatible:
>> +      const: amd,pensando-elba-sd4hc
>
>BTW, this probably won't even work and that's the answer why you added
>fake maxItems: 2... This should make you think about the bug. You must
>use contains.

That was the problem, see updated diff below.  Passes dtbs_check and dt_binding_check.

>> +then:
>> +  properties:
>> +    reg:
>> +      minItems: 2
>> +else:
>> +  properties:
>> +    reg:
>> +      minItems: 1
>> +      maxItems: 2
>
>No, why do you suddenly allow two items on all variants? This was not
>described in your commit msg at all, so I expect here maxItems: 1.

Set maxItems: 1.

>Also, unless your reset is applicable to all variants, resets: false and
>reset-names: false.

Added false for both, this is the diff with above changes

--- a/Documentation/devicetree/bindings/mmc/cdns,sdhci.yaml
+++ b/Documentation/devicetree/bindings/mmc/cdns,sdhci.yaml
@@ -9,19 +9,18 @@ title: Cadence SD/SDIO/eMMC Host Controller (SD4HC)
 maintainers:
   - Masahiro Yamada <yamada.masahiro@socionext.com>
 
-allOf:
-  - $ref: mmc-controller.yaml
-
 properties:
   compatible:
     items:
       - enum:
+          - amd,pensando-elba-sd4hc
           - microchip,mpfs-sd4hc
           - socionext,uniphier-sd4hc
       - const: cdns,sd4hc
 
   reg:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
 
   interrupts:
     maxItems: 1
@@ -111,12 +110,42 @@ properties:
     minimum: 0
     maximum: 0x7f
 
+  reset-names:
+    items:
+      - const: hw
+
+  resets:
+    description:
+      physical line number to hardware reset the mmc
+    maxItems: 1
+
 required:
   - compatible
   - reg
   - interrupts
   - clocks
 
+allOf:
+  - $ref: mmc-controller.yaml
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: amd,pensando-elba-sd4hc
+    then:
+      required:
+        - reset-names
+        - resets
+      properties:
+        reg:
+          minItems: 2
+    else:
+      properties:
+        reset-names: false
+        resets: false
+        reg:
+          maxItems: 1
+

Regards,
Brad
