Re: [PATCH v3 1/2] dt-bindings: mtd: amlogic,meson-nand: support fields for boot ROM code

From: Arseniy Krasnov <avkrasnov@salutedevices.com>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Neil Armstrong <neil.armstrong@linaro.org>,
	Kevin Hilman <khilman@baylibre.com>,
	Jerome Brunet <jbrunet@baylibre.com>,
	Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
	<linux-mtd@lists.infradead.org>, <devicetree@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-amlogic@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <oxffffaa@gmail.com>,
	<kernel@sberdevices.ru>
Subject: Re: [PATCH v3 1/2] dt-bindings: mtd: amlogic,meson-nand: support fields for boot ROM code
Date: Wed, 10 Apr 2024 17:48:02 +0300	[thread overview]
Message-ID: <588551c9-3426-e623-e2aa-70b040c9324a@salutedevices.com> (raw)
In-Reply-To: <20240410122356.30852b3c@xps-13>

Hi,

On 10.04.2024 13:23, Miquel Raynal wrote:
> Hi Arseniy,
> 
> avkrasnov@salutedevices.com wrote on Tue, 9 Apr 2024 21:10:24 +0300:
> 
>> Boot ROM code on Meson requires that some pages on NAND must be written
>> in special mode: "short" ECC mode where each block is 384 bytes and
>> scrambling mode is on. Such pages located with the specified interval
>> within specified offset. Both interval and offset are located in the
>> device tree and used by driver if 'nand-is-boot-medium' is set for
>> NAND chip.
>>
>> Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
>> ---
>>  .../bindings/mtd/amlogic,meson-nand.yaml           | 14 ++++++++++++++
>>  1 file changed, 14 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
>> index 57b6957c8415..b86a1953056b 100644
>> --- a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
>> +++ b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
>> @@ -64,11 +64,25 @@ patternProperties:
>>          items:
>>            maximum: 0
>>  
>> +      amlogic,boot-page-last:
>> +        $ref: /schemas/types.yaml#/definitions/uint32
>> +        description:
>> +          The NFC driver needs this information to select ECC
>> +          algorithms supported by the boot ROM.
> 
> Shall we have a length rather than the last page?

You mean rename it to "amlogic,boot-pages-length" or something like that ? But I think
length in bytes is useless here:
1) boot rom needs that only some single pages are written in special mode (and as I see in
   vendor's driver it also works in pages).
2) NAND driver operates in pages during write/read such pages.

So length in bytes will be converted to pages anyway.

What do You think ?

Thanks, Arseniy

> 
>> +
>> +      amlogic,boot-page-step:
>> +        $ref: /schemas/types.yaml#/definitions/uint32
>> +        description:
>> +          The NFC driver needs this information to select ECC
>> +          algorithms supported by the boot ROM (in pages).
>> +
>>      unevaluatedProperties: false
>>  
>>      dependencies:
>>        nand-ecc-strength: [nand-ecc-step-size]
>>        nand-ecc-step-size: [nand-ecc-strength]
>> +      amlogic,boot-page-last: [nand-is-boot-medium, "amlogic,boot-page-step"]
>> +      amlogic,boot-page-step: [nand-is-boot-medium, "amlogic,boot-page-last"]
>>  
>>  
>>  required:
> 
> 
> Thanks,
> Miquèl

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