Re: [PATCH 11/11] MIPS: mobileye: eyeq5: add octal flash node to eval board DTS

[Pratyush Yadav <pratyush@kernel.org>]

On Mon, Mar 11 2024, Tudor Ambarus wrote:

> On 3/8/24 17:18, Théo Lebrun wrote:
>> Add SPI-NOR octal flash node to evaluation board devicetree.
>> 
>> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
>> ---
>>  arch/mips/boot/dts/mobileye/eyeq5-epm5.dts | 15 +++++++++++++++
>>  1 file changed, 15 insertions(+)
>> 
>> diff --git a/arch/mips/boot/dts/mobileye/eyeq5-epm5.dts b/arch/mips/boot/dts/mobileye/eyeq5-epm5.dts
>> index 6898b2d8267d..0e5fee7b680c 100644
>> --- a/arch/mips/boot/dts/mobileye/eyeq5-epm5.dts
>> +++ b/arch/mips/boot/dts/mobileye/eyeq5-epm5.dts
>> @@ -21,3 +21,18 @@ memory@0 {
>>  		      <0x8 0x02000000 0x0 0x7E000000>;
>>  	};
>>  };
>> +
>> +&ospi {
>> +	flash0: flash@0 {
>> +		compatible = "jedec,spi-nor";
>> +		reg = <0>; /* chip select */
>> +
>> +		spi-max-frequency = <40000000>;
>> +		spi-rx-bus-width = <8>;
>> +		cdns,read-delay = <1>;
>> +		cdns,tshsl-ns = <400>;
>> +		cdns,tsd2d-ns = <400>;
>> +		cdns,tchsh-ns = <125>;
>> +		cdns,tslch-ns = <50>;
>
> These cdns properties look bad, they bypass SPI NOR entirely. I'd check
> if these timings can be determined at SFDP parsing time, then I'd pass
> them to the SPI controller.

I agree, but I don't see any table in SFDP that describes these timings.
So I don't think there is a way to discover them.

>
> I see these properties are already accepted in the bindings file for few
> years now. Something to improve later on.

-- 
Regards,
Pratyush Yadav