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Message-ID: <b623a374-4e2f-7160-8d11-75f9beaac42b@salutedevices.com>
Date: Wed, 10 Apr 2024 17:51:03 +0300
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Subject: Re: [PATCH v3 1/2] dt-bindings: mtd: amlogic,meson-nand: support
 fields for boot ROM code
Content-Language: en-US
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>
References: <20240409181025.55504-1-avkrasnov@salutedevices.com>
 <20240409181025.55504-2-avkrasnov@salutedevices.com>
 <20240410122356.30852b3c@xps-13>
 <588551c9-3426-e623-e2aa-70b040c9324a@salutedevices.com>
 <20240410170040.37a59ff6@xps-13>
From: Arseniy Krasnov <avkrasnov@salutedevices.com>
In-Reply-To: <20240410170040.37a59ff6@xps-13>
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On 10.04.2024 18:00, Miquel Raynal wrote:
> Hi Arseniy,
> 
> avkrasnov@salutedevices.com wrote on Wed, 10 Apr 2024 17:48:02 +0300:
> 
>> 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 ?
> 
> I didn't talk about units :-)
> 
> Maybe: amlogic,boot-pages would make sense? But pointing at the last
> page seems weird.

Ah ok I see. Got it!

Thanks, Arseniy

> 
> Miquèl