Re: [EXT] Re: [PATCH 1/2 v7] dt-bindings: watchdog: marvell GTI system watchdog driver

From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Sunil Kovvuri Goutham <sgoutham@marvell.com>,
	Bharat Bhushan <bbhushan2@marvell.com>,
	"wim@linux-watchdog.org" <wim@linux-watchdog.org>,
	"linux@roeck-us.net" <linux@roeck-us.net>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"krzysztof.kozlowski+dt@linaro.org" 
	<krzysztof.kozlowski+dt@linaro.org>,
	"linux-watchdog@vger.kernel.org" <linux-watchdog@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [EXT] Re: [PATCH 1/2 v7] dt-bindings: watchdog: marvell GTI system watchdog driver
Date: Tue, 16 May 2023 12:25:07 +0200	[thread overview]
Message-ID: <578a743e-dee4-59b7-2f4e-290b551211e0@linaro.org> (raw)
In-Reply-To: <BY3PR18MB4737947E20CB44CE6DAB940DC6799@BY3PR18MB4737.namprd18.prod.outlook.com>

On 16/05/2023 12:06, Sunil Kovvuri Goutham wrote:

>>>>> Marvell have octeontx2 series of processor which have watchdog timer.
>>>>> In 95xx,98xx,96xx are the processors in octeontx2 series of
>>>>> processor. So
>>>> octeontx2-95xx is on soc, octeontx2-96xx is another and so on.
>>>>
>>>> No, 95xx is not a processor. Otherwise please point me to exact
>>>> product datasheet. Hint: I checked it.
>>>
>>> Looks like 95xx data sheet is not public, will remove in that case.
>>
>> We can talk about 96xx. Can you point me to the SoC named exactly like this?
>> Hint: I checked it.
> 
> To recap what Bharat mentioned before along with references to individual processors.
> OcteonTx2 is a family of processors
> https://www.marvell.com/products/data-processing-units.html
> Please check for "OCTEON TX2 DPUs"
> CN96xx and CN98xx are two silicon variants in this family.
> https://www.marvell.com/content/dam/marvell/en/public-collateral/embedded-processors/marvell-infrastructure-processors-octeon-tx2-cn92xx-cn96xx-cn98xx-product-brief-2020-02.pdf

This is a product brief which further suggests CN96xx is a family (or
sub-family).

"xx" is pretty often used as family, not as product. Otherwise how one
product CN92XX can come with 12-18 cores *in the same time*?

https://www.marvell.com/company/newsroom/marvell-announces-octeon-tx2-family-of-multi-core-infrastructure-processors.html
"Marvell’s CN91xx, CN92xx, CN96xx, and CN98xx processor families include:"

https://www.marvell.com/products/data-processing-units.html

> And CNF95xx is another silicon variant in the same family.
> https://www.marvell.com/content/dam/marvell/en/public-collateral/embedded-processors/marvell-infrastructure-processors-octeon-fusion-cnf95xx-product-brief.pdf

Again, unspecific product brief. Your other briefs specify them clearer,
e.g. CN9130, CN9131

> 
> Since the HW block is same in all the variants of silicons in this family, we would like to use a
> generic string instead of different compatible string for each one. ie
> - const: marvell,octeontx2-wdt
> Hope this is okay.

https://elixir.bootlin.com/linux/v6.1-rc1/source/Documentation/devicetree/bindings/writing-bindings.rst#L42

> 
> Same with CN10K or Octeon10 family of silicons.
> https://www.marvell.com/products/data-processing-units.html
> Please check for "OCTEON 10"
> 
> CN103xx and CN106xx are two silicons in this family.

Are they? "Up to 8" cores, so how this can be one specific silicon? One
customer buys CN10300 with 8 cores, second buys exactly the same CN10300
and has 4 cores?

You are mixing families and specific devices.

Best regards,
Krzysztof