ADP5588 linux driver problem accessing through GPIO char device gpio-event-mon.c tool

Hi Alberto,

We are working on developing newer software support for windows for ADP5587 which will be carried over to ADP5588. Linux is no longer supported and we don't have resource to check this problem for you. Can you review if you will be able to make use of a windows based program?

Can you share what is project info and estimate annual usage?

Hi, the ADP5587 is controlled for an Embedded ARM processor running Linux. Application is fleet management, estimated qty around 20ku/y. Thanks

Aliberal said:

My doubt is:

Why the irq_unmask() callback function is called after the irq_bus_sync_unlock() one when the gpio char device access trhough the tool is used? Checking your driver the unmask of the GPIO interrupt is done in the irq_unmask() function.  If irq_unmask() is called after irq_bus_sync_unlock(), then the unmask value is not transmitted to the device through I2C via the  irq_bus_sync_unlock() function.  

So, is there an observable behavior that is wrong?

Looking at the driver code, it looks like it is hooking into the correct places for the irq_chip struct.

Hi,

In my opinion irq_unmask() should be called before irq_bus_sync_unlock(). The idea is to unmask the interrupt in irq_unmask() and then transmit the new value via I2C to the device using irq_bus_sync_unlock(). What is the sense of unmasking the interrupt after updating the value to the register of the device via I2C? Maybe i am missing something but i think that this behavior is wrong.

Best Regards

I think we are debathing here some old Linux interface.

This forum isn't meant to do that.

AFAICT, the driver hooks into the Linux kernel, and it is the kernel calling the driver routine.

static void adp5588_irq_unmask(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct adp5588_gpio *dev = gpiochip_get_data(gc);

        dev->irq_mask[ADP5588_BANK(d->hwirq)] |= ADP5588_BIT(d->hwirq);
}

static struct irq_chip adp5588_irq_chip = {
        .name                   = "adp5588",
        .irq_mask               = adp5588_irq_mask,
        .irq_unmask             = adp5588_irq_unmask,
        .irq_bus_lock           = adp5588_irq_bus_lock,
        .irq_bus_sync_unlock    = adp5588_irq_bus_sync_unlock,
        .irq_set_type           = adp5588_irq_set_type,
};

If there are doubts about the correctness of this interface, then maybe these are better suited for discussion on the Linux kernel list, not here.

There are many wonky/funky semantics in the kernel.

It is how the maintainers designed them in that moment in time.

One example, is the   regulator_get_optional()  vs   regulator_get(). regulator_get_optional() will return an error if there is no regulator, regulator_get() will create a dummy regulator.

On the other hand, gpiod_get_optional() will return a NULL gpio object, while gpiod_get() will return an error if there is no GPIO. Similar is for clck_get_optional() and clk_get()

So, if there are issues with the ADP5588, this is the place to raise issues.

But, if there are issues/doubts with the Linux interface, the place is the Linux mailing list.

Thanks for your comments! I have already solved it. It was a problem in my SW configuration. The Linux driver is working fine. Best Regards. Alberto