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Subject: Re: [PATCH] mtd: spi-nor: add support for Microchip 25LC256
To:     Radu Pirea <radu.pirea@microchip.com>,
        Boris Brezillon <boris.brezillon@bootlin.com>
Cc:     linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
        Zhiqiang.Hou@nxp.com, pp@emlix.com, richard@nod.at,
        computersforpeace@gmail.com, dwmw2@infradead.org
References: <20180504155404.5285-1-radu.pirea@microchip.com>
 <20180504204013.254d90cf@bbrezillon>
 <e2e23aa21b37754b0c84003e6d87c7cb7d5a17fe.camel@microchip.com>
 <1db092c8-95fb-5747-f7b9-f6a215b1aa5b@gmail.com>
 <a34429cf43124de623fcaa645d5d7a360c755867.camel@microchip.com>
From:   Marek Vasut <marek.vasut@gmail.com>
Message-ID: <30ab9516-abc9-d2d5-79ea-266c682c5fa9@gmail.com>
Date:   Wed, 16 May 2018 15:47:15 +0200
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On 05/16/2018 12:05 PM, Radu Pirea wrote:
> On Wed, 2018-05-16 at 00:17 +0200, Marek Vasut wrote:
>> On 05/15/2018 06:22 PM, Radu Pirea wrote:
>>> On Fri, 2018-05-04 at 20:40 +0200, Boris Brezillon wrote:
>>>> On Fri, 4 May 2018 18:54:04 +0300
>>>> Radu Pirea <radu.pirea@microchip.com> wrote:
>>>>
>>>>> Added geometry description for Microchip 25LC256 memory.
>>>>
>>>> Same as for the dataflash stuff you posted a few weeks ago: I
>>>> don't
>>>> think this device belongs in the SPI NOR framework.
>>>
>>> Hi Boris,
>>>
>>> 25lc256 memory is similar with mr25h256, the only difference is the
>>> page size(64 vs 256). Because mr25h256 is already in SPI NOR
>>> framework
>>> I added here 25lc256.
>>
>> I think I must be reading the wrong datasheet, but can you show me
>> how
>> does it support things like READID opcode ?
>>
> Hi Marek,
> 
> I read the datasheet for 25lc256 and for mr25h256 and none of them
> supports READID. Is this required for a chip to be included in spi-nor
> framework? I just followed the mr25h256 as an example. 

So I thought until you pointed out the MR25 devices.

Does the 25LC device need erase or not ? I think the MR25s didn't, but I
might be wrong.

Maybe the framework could support the 25LC afterall.

-- 
Best regards,
Marek Vasut