Re: [PATCH net-next 11/12] net: pse-pd: Add support for event reporting using devm_regulator_irq_helper

[Kory Maincent <kory.maincent@bootlin.com>]

On Thu, 3 Oct 2024 01:52:20 +0200
Andrew Lunn <andrew@lunn.ch> wrote:

> > +int devm_pse_irq_helper(struct pse_controller_dev *pcdev, int irq,
> > +			int irq_flags, int supported_errs,
> > +			const struct pse_irq_desc *d)
> > +{
> > +	struct regulator_dev **rdevs;
> > +	void *irq_helper;
> > +	int i;
> > +
> > +	rdevs = devm_kcalloc(pcdev->dev, pcdev->nr_lines,
> > +			     sizeof(struct regulator_dev *), GFP_KERNEL);
> > +	if (!rdevs)
> > +		return -ENOMEM;
> > +
> > +	for (i = 0; i < pcdev->nr_lines; i++)
> > +		rdevs[i] = pcdev->pi[i].rdev;
> > +
> > +	/* Register notifiers - can fail if IRQ is not given */
> > +	irq_helper = devm_regulator_irq_helper(pcdev->dev, d, irq,
> > +					       0, supported_errs, NULL,
> > +					       &rdevs[0],
> > pcdev->nr_lines);  
> 
> Should irq_flags be passed through? I'm guessing one usage of it will
> be IRQF_SHARED when there is one interrupt shared by a number of
> controllers.

Oh yes, you are right! Thanks for spotting it!

> > From: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
> > 
> > Add support for devm_pse_irq_helper(), a wrapper for
> > devm_regulator_irq_helper(). This aims to report events such as
> > over-current or over-temperature conditions similarly to how the regulator
> > API handles them. Additionally, this patch introduces several define
> > wrappers to keep regulator naming conventions out of PSE drivers.  
> 
> I'm missing something here, i think.
> 
> https://docs.kernel.org/power/regulator/consumer.html#regulator-events
> 
> Suggests these are internal events, using a notification chain. How
> does user space get to know about such events?

When events appears, _notifier_call_chain() is called which can generate netlink
messages alongside the internal events:
https://elixir.bootlin.com/linux/v6.11.1/source/drivers/regulator/core.c#L4898

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com