在 2022/12/13 下午5:36, Linus Walleij 写道:
On Mon, Dec 12, 2022 at 9:13 AM Yinbo Zhu <zhuyinbo@xxxxxxxxxxx> wrote:
mask_irq/unmask_irq/irq_ack/ function always be called by
handle_level_irq/handle_edge_irq in current irq domain. and the
handle_level_irq/handle_edge_irq will be called by handle_irq_desc that
ask know which irq is.
when a peripheral need to use a gpio irq that gpio irq driver need know
irq status and call irq desc->irq_handler.
so I don't got it about which case it is unnecessary to know which irq.
Sorry I don't understand what you are asking, can you elaborate?
Do you mean that you don't know which driver will not call ->to_irq()
on the gpiochip? That would be any driver that takes an IRQ directly in
the device tree:
gpio: gpio {
interrupt-controller;
#interrupt-cells = <2>;
....
};
device {
interrupts = <&gpio 14 IRQ_TYPE_LEVEL_HIGH>;
....
};
This case will only call the irqchip callbacks and will never call
the .to_irq() on the gpio_chip.
I mean that if the current domain is a valid doamin, every interrupt
must have an interrupt status.
If there is no interrupt status, no one can cover the interrupt,
and no one will call 14 irq's desc->handle_irq (handle_level_irq)
and Loongson-2 gpio doesn't have irq status register, so Loongson-2
gpio irqchip shouldn't be implemented.
You find an example of a hierarchical GPIO irqchip using the
GPIOLIB_IRQCHIP in drivers/gpio/gpio-ixp4xx.c.
Loongson-2 gpio irq hardware only a enable register, and when a gpio irq
happen, then will has a such flow: "cpuintc -> liointc -> gpioinc ->
generic_handle_domain_irq -> handle_level_irq ->
peripheral-action(action->handler)"
generic_handle_domain_irq need rely on specific hwirq that ask gpio irq
hardware has a status register but Loongson-2 gpio irq hardware doesn't
have it.
so I still think it wasn't appropriate that for loongson-2 gpio driver
add a irq chip.
generic_handle_domain_irq() is of no concern, what matters is if
your interrupt is hierarchical or not, the callback in the GPIO chip
can be a simple remapping of the numberspace followed by
a call to the parent callbacks.
Yours,
Linus Walleij
Hi
I think gpio irq domain should be a normal irq domain that like other
irq domain. that need a function A to call virq desc handler in gpio irq
domain. if no use generic_handler_domain_irq or similar interface,
that will no one to call irq_desc->irq_handler.
"cpuintc -> liointc -> gpioinc -> generic_handle_domain_irq ->
handle_level_irq -> peripheral-action(action->handler)"
