linux-kernel - Re: [PATCH v1 1/7] spmi: Implement spmi_subdevice_alloc_and

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <cb34fd4e-d87a-4a98-b27e-93ecb851e85e@collabora.com>
Date: Mon, 21 Jul 2025 15:00:13 +0200
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
To: Andy Shevchenko <andriy.shevchenko@...el.com>
Cc: sboyd@...nel.org, jic23@...nel.org, dlechner@...libre.com,
 nuno.sa@...log.com, andy@...nel.org, arnd@...db.de,
 gregkh@...uxfoundation.org, srini@...nel.org, vkoul@...nel.org,
 kishon@...nel.org, sre@...nel.org, krzysztof.kozlowski@...aro.org,
 u.kleine-koenig@...libre.com, linux-arm-msm@...r.kernel.org,
 linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-phy@...ts.infradead.org, linux-pm@...r.kernel.org,
 kernel@...labora.com, wenst@...omium.org
Subject: Re: [PATCH v1 1/7] spmi: Implement spmi_subdevice_alloc_and_add() and
 devm variant

Il 21/07/25 13:34, Andy Shevchenko ha scritto:
> On Mon, Jul 21, 2025 at 09:55:19AM +0200, AngeloGioacchino Del Regno wrote:
>> Some devices connected over the SPMI bus may be big, in the sense
>> that those may be a complex of devices managed by a single chip
>> over the SPMI bus, reachable through a single SID.
>>
>> Add new functions aimed at managing sub-devices of a SPMI device
>> spmi_subdevice_alloc_and_add() and a spmi_subdevice_put_and_remove()
>> for adding a new subdevice and removing it respectively, and also
>> add their devm_* variants.
>>
>> The need for such functions comes from the existance of	those
>> complex Power Management ICs (PMICs), which feature one or many
>> sub-devices, in some cases with these being even addressable on
>> the chip in form of SPMI register ranges.
>>
>> Examples of those devices can be found in both Qualcomm platforms
>> with their PMICs having PON, RTC, SDAM, GPIO controller, and other
>> sub-devices, and in newer MediaTek platforms showing similar HW
>> features and a similar layout with those also having many subdevs.
> 
> ...
> 
>>   EXPORT_SYMBOL_GPL(devm_spmi_controller_add);
> 
>> +EXPORT_SYMBOL_GPL(devm_spmi_subdevice_alloc_and_add);
> 
> I am wondering how hard to move these to a dedicated namespace.
> Basically you can define a default namespace, and at the same time
> add import to all (current) users.
> 

I can check if this can be done "relatively easily" (as in, if I can do that
without requiring "a hundred" immutable branches for every subsystem using
SPMI).

If turns out being feasible - I do actually like the idea so yes I'd be pleased
to do that... even though honestly it's completely out of scope for this series.

In case I can't - it's still something that can be done later.

> ...
> 
>> +	dev_set_name(&sdev->dev,
>> +		     "%d-%02x.%d.auto", sdev->ctrl->nr, sdev->usid, sub_sdev->devid);
> 
> No error check?
> 

Heh, whoops, forgot about it :-)

Thanks for catching that - adding the check for v2.

Cheers,
Angelo