Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <9d33314e-97da-dc47-8361-2e45b75fa566@canonical.com>
Date:   Sat, 19 Feb 2022 16:41:28 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.5.0
Subject: Re: [PATCH v2] dt-bindings: memory: lpddr2: Adjust revision ID
 property to match lpddr3
Content-Language: en-US
To:     Julius Werner <jwerner@chromium.org>
Cc:     Dmitry Osipenko <digetx@gmail.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220219012457.2889385-1-jwerner@chromium.org>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
In-Reply-To: <20220219012457.2889385-1-jwerner@chromium.org>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 19/02/2022 02:24, Julius Werner wrote:
> Commit 3539a2 (dt-bindings: memory: lpddr2: Add revision-id properties)
> added the properties `revision-id1` and `revision-id2` to the
> "jedec,lpddr2" binding. The "jedec,lpddr3" binding already had a single
> array property `revision-id` for the same purpose. For consistency
> between related memory types, this patch deprecates the LPDDR2
> properties and instead adds a property in the same style as for LPDDR3
> to that binding.
> 
> Signed-off-by: Julius Werner <jwerner@chromium.org>
> ---
>  .../memory-controllers/ddr/jedec,lpddr2.yaml       | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
> index 25ed0266f6dd3d..37229738f47271 100644
> --- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
> +++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
> @@ -30,12 +30,23 @@ properties:
>      maximum: 255
>      description: |
>        Revision 1 value of SDRAM chip. Obtained from device datasheet.
> +      Property is deprecated, use revision-id instead.
> +    deprecated: true
>  
>    revision-id2:
>      $ref: /schemas/types.yaml#/definitions/uint32
>      maximum: 255
>      description: |
>        Revision 2 value of SDRAM chip. Obtained from device datasheet.
> +      Property is deprecated, use revision-id instead.
> +    deprecated: true
> +
> +  revision-id:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    minItems: 2
> +    maxItems: 2

You need maximum value under items.  See:
Documentation/devicetree/bindings/arm/l2c2x0.yaml

> +    description: |
> +      Revision IDs read from Mode Register 6 and 7. One byte per uint32 cell (i.e. <MR6 MR7>).
>  
>    density:
>      $ref: /schemas/types.yaml#/definitions/uint32
> @@ -164,8 +175,7 @@ examples:
>          compatible = "elpida,ECB240ABACN", "jedec,lpddr2-s4";
>          density = <2048>;
>          io-width = <32>;
> -        revision-id1 = <1>;
> -        revision-id2 = <0>;
> +        revision-id = <123 234>;

Don't change the original values.

Plus what Dmitry pointed out.

>  
>          tRPab-min-tck = <3>;
>          tRCD-min-tck = <3>;


Best regards,
Krzysztof