Re: [PATCH 2/2] soc: nxp: Add a simple NXP LPC32xx socinfo driver

[Krzysztof Kozlowski <krzk@kernel.org>]

On 03/01/2026 23:14, Vladimir Zapolskiy wrote:
> On 1/3/26 14:43, Krzysztof Kozlowski wrote:
>> On 02/01/2026 14:21, Vladimir Zapolskiy wrote:
>>> On 1/2/26 14:54, Krzysztof Kozlowski wrote:
>>>> On 02/01/2026 13:36, Vladimir Zapolskiy wrote:
>>>>> On 1/2/26 11:58, Krzysztof Kozlowski wrote:
>>>>>> On 02/01/2026 00:56, Vladimir Zapolskiy wrote:
>>>>>>> Add NXP LPC32xx specific driver to get unique SoC ID from System Control
>>>>>>> Block registers and export it to userspace.
>>>>>>>
>>>>>>> Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
>>>>>>> ---
>>>>>>>     drivers/soc/Kconfig           |   1 +
>>>>>>>     drivers/soc/Makefile          |   1 +
>>>>>>>     drivers/soc/nxp/Kconfig       |  16 +++++
>>>>>>>     drivers/soc/nxp/Makefile      |   2 +
>>>>>>>     drivers/soc/nxp/lpc32xx-soc.c | 114 ++++++++++++++++++++++++++++++++++
>>>>>>>     5 files changed, 134 insertions(+)
>>>>>>>     create mode 100644 drivers/soc/nxp/Kconfig
>>>>>>>     create mode 100644 drivers/soc/nxp/Makefile
>>>>>>>     create mode 100644 drivers/soc/nxp/lpc32xx-soc.c
>>>>>>>
>>>>>>> diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
>>>>>>> index a2d65adffb80..c21b0d2f58fc 100644
>>>>>>> --- a/drivers/soc/Kconfig
>>>>>>> +++ b/drivers/soc/Kconfig
>>>>>>> @@ -18,6 +18,7 @@ source "drivers/soc/loongson/Kconfig"
>>>>>>>     source "drivers/soc/mediatek/Kconfig"
>>>>>>>     source "drivers/soc/microchip/Kconfig"
>>>>>>>     source "drivers/soc/nuvoton/Kconfig"
>>>>>>> +source "drivers/soc/nxp/Kconfig"
>>>>>>>     source "drivers/soc/pxa/Kconfig"
>>>>>>>     source "drivers/soc/qcom/Kconfig"
>>>>>>>     source "drivers/soc/renesas/Kconfig"
>>>>>>> diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
>>>>>>> index 47a3925ff84c..a04c21a8a5a4 100644
>>>>>>> --- a/drivers/soc/Makefile
>>>>>>> +++ b/drivers/soc/Makefile
>>>>>>> @@ -24,6 +24,7 @@ obj-y				+= loongson/
>>>>>>>     obj-y				+= mediatek/
>>>>>>>     obj-y				+= microchip/
>>>>>>>     obj-y				+= nuvoton/
>>>>>>> +obj-y				+= nxp/
>>>>>>>     obj-y				+= pxa/
>>>>>>>     obj-y				+= qcom/
>>>>>>>     obj-y				+= renesas/
>>>>>>
>>>>>> Missing maintainers entry.
>>>>>>
>>>>>>
>>>>>>> +
>>>>>>> +static int lpc32xx_soc_probe(struct platform_device *pdev)
>>>>>>> +{
>>>>>>> +	struct soc_device_attribute *soc_dev_attr;
>>>>>>> +	struct device *dev = &pdev->dev;
>>>>>>> +	struct soc_device *soc_dev;
>>>>>>> +	struct regmap *scb;
>>>>>>> +	u32 serial_id[4];
>>>>>>> +	int ret;
>>>>>>> +
>>>>>>> +	soc_dev_attr = devm_kzalloc(dev, sizeof(*soc_dev_attr), GFP_KERNEL);
>>>>>>> +	if (!soc_dev_attr)
>>>>>>> +		return -ENOMEM;
>>>>>>> +
>>>>>>> +	soc_dev_attr->family = "NXP LPC32xx";
>>>>>>> +
>>>>>>> +	ret = of_property_read_string(of_root, "model", &soc_dev_attr->machine);
>>>>>>> +	if (ret)
>>>>>>> +		return ret;
>>>>>>> +
>>>>>>> +	scb = syscon_regmap_lookup_by_compatible("nxp,lpc3220-scb");
>>>>>>
>>>>>> This is undocumented ABI.
>>>>>
>>>>> What is the expected level of documentation for syscon?
>>>>
>>>> git grep nxp,lpc3220-scb
>>>>
>>>> gives me 0 results.
>>>>
>>>> Documentation is supposed to be in this patchset. If it is not, you have
>>>> changelog part to explain dependencies and unusual things.
>>>
>>> The documentation is under review, as a DT maintainer you are in To: list
>>> and should have it in the mailbox, for anyone's convenience the dependency
>>> is mentioned in the cover letter to this changeset also.
>>
>> There is nothing about dependency and nothing about binding in the cover
>> letter, so no - this is not explained nowhere and must have been explained.
>>
> 
> If you do not find the asked information, then let me repeat my question, what
> dependency or information does this changeset miss? What "undocumented ABI"
> you'd expect to resolve?

I already explained that.

You added here new undocumented ABI. I said that.

Changelog of this patch or cover letter must say where is the ABI
documented, if it is not in this patchset. I basically said it as well.

There is nothing like this in cover letter. There is nothing about
dependency, either.


Best regards,
Krzysztof