Re: [PATCH v3 11/16] gpio: add support for the sl28cpld GPIO controller

[Michael Walle]

Am 2020-04-27 13:45, schrieb Thomas Gleixner:
> Michael Walle <michael@xxxxxxxx> writes:
> > +struct sl28cpld_gpio {
> > +	struct regmap_irq_chip irq_chip;
> > +	struct regmap_irq_chip_data *irq_data;
> > +};
> > +
> > +static const struct regmap_irq sl28cpld_gpio_irqs[] = {
> > +	REGMAP_IRQ_REG_LINE(0, 8),
> > +	REGMAP_IRQ_REG_LINE(1, 8),
> > +	REGMAP_IRQ_REG_LINE(2, 8),
> > +	REGMAP_IRQ_REG_LINE(3, 8),
> > +	REGMAP_IRQ_REG_LINE(4, 8),
> > +	REGMAP_IRQ_REG_LINE(5, 8),
> > +	REGMAP_IRQ_REG_LINE(6, 8),
> > +	REGMAP_IRQ_REG_LINE(7, 8),
> > +};
>
> This is exactly the same as the one in the irq chip patch.

To my knowledge this boilerplate is just to describe this
irqchip has 8 different IRQs.

> > +static int sl28cpld_gpio_irq_init(struct device *dev,
> > +				  struct sl28cpld_gpio *gpio,
> > +				  struct regmap *regmap, unsigned int base,
> > +				  int irq)
> > +{
> > +	struct regmap_irq_chip *irq_chip = &gpio->irq_chip;
> > +
> > +	irq_chip->name = "sl28cpld-gpio-irq",
> > +	irq_chip->irqs = sl28cpld_gpio_irqs;
> > +	irq_chip->num_irqs = ARRAY_SIZE(sl28cpld_gpio_irqs);
> > +	irq_chip->num_regs = 1;
> > +	irq_chip->status_base = base + GPIO_REG_IP;
> > +	irq_chip->mask_base = base + GPIO_REG_IE;
> > +	irq_chip->mask_invert = true,
> > +	irq_chip->ack_base = base + GPIO_REG_IP;
> > +
> > +	return devm_regmap_add_irq_chip_np(dev, dev_of_node(dev), regmap,
> > +					   irq, IRQF_SHARED | IRQF_ONESHOT, 0,
> > +					   irq_chip, &gpio->irq_data);
> > +}
>
> And this looks pretty familiar as well. What's the point of duplicating
> that code?

this is also just boilerplate to configure the irqchip. But there are 
two
distinct blocks inside the board management controller:
 - an interrupt controller (which has 8 interrupts)
 - and gpio controllers which also happen to have 8 interrupts and
   both have some shared semantics for now. But the GPIO building block
   might be extended to provide interrupt type settings, i.e. falling/
   rising/level triggered interrupts.

So yes both look similar, but they are two different blocks, they use
different registers and they might drift apart in the future.

-michael

> Thanks,
>
>         tglx