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Subject: Re: [PATCH] docs: mtd: Update spi nor reference driver
To:     Vignesh Raghavendra <vigneshr@ti.com>,
        Schrempf Frieder <frieder.schrempf@kontron.de>,
        "corbet@lwn.net" <corbet@lwn.net>,
        "mchehab+samsung@kernel.org" <mchehab+samsung@kernel.org>,
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From:   John Garry <john.garry@huawei.com>
Message-ID: <c5e063e8-5025-8206-f819-6ce5228ef0fb@huawei.com>
Date:   Tue, 20 Aug 2019 15:09:15 +0100
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On 19/08/2019 05:39, Vignesh Raghavendra wrote:
> Hi,
>
> On 16/08/19 3:50 PM, John Garry wrote:
>> On 06/08/2019 17:40, Schrempf Frieder wrote:
> [...]
>>
>> Hi,
>>
>> Could someone kindly advise on the following:
>>

Hi Vignesh,

>> I am looking at ACPI support only for an mtd spi nor driver we're
>> targeting for mainline support.
>>
>
> If its a new driver, please add it under drivers/spi implementing SPI
> MEM framework.
> There are few drivers under drivers/spi that can be used as example.
> (Search for "spi_mem_ops"

Ok, fine. I note that in doing this I would still be using the spi nor 
framework indirectly through the m25p80 driver.

>> So for the host, I could use a proprietary HID in the DSDT for matching
>> in the kernel driver.
>>
>> About the child spi flash devices, is the recommendation to just use
>> PRP0001 HID and "jedec,spi-nor" compatible?
>>
>
> I am not quite familiar with ACPI systems, but child flash device should
> use "jedec,spi-nor" as compatible.

Right, so to use SPI MEM framework, it looks like I will have to use 
PRP0001 and "jedec,spi-nor" as compatible.

My reluctance in using PRP0001 and compatible "jedec,spi-nor" is how 
other OS can understand this.

All the best,
John

>
> Regards
> Vignesh
>
>> thanks,
>> John
>>
>>