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    SubjectRe: [PATCH 02/11] arm: pxa27x: support ICP DAS LP-8x4x
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    On Tue, 2013-12-10 at 13:33 +0100, Linus Walleij wrote:
    > On Fri, Dec 6, 2013 at 6:14 PM, Arnd Bergmann <arnd@arndb.de> wrote:
    > > On Friday 06 December 2013, Sergei Ianovich wrote:
    > >> On Fri, 2013-12-06 at 01:40 +0100, Arnd Bergmann wrote:
    > >>
    > >> > > +
    > >> > > +static struct irq_chip lp8x4x_irq_chip = {
    > >> > > + .name = "FPGA",
    > >> > > + .irq_ack = lp8x4x_ack_irq,
    > >> > > + .irq_mask = lp8x4x_mask_irq,
    > >> > > + .irq_unmask = lp8x4x_unmask_irq,
    > >> > > +};
    > >> >
    > >> > Please try to move the irqchip code to drivers/irqchip/.
    > >>
    > >> CONFIG_IRQCHIP depends on CONFIG_OF_IRQ which in turn depends on Open
    > >> Firmware.
    > >
    > > Hmm, I wonder if we should try to change Kconfig then. Let's leave it
    > > alone for now, maybe Linus Walleij has some comments since he has
    > > been looking into moving drivers out in the past.
    >
    > I don't get this, if the subarch has deps in place for IRQCHIP and
    > OF_IRQ just move the implementation to drivers/irqchip/foo.c
    > edit drivers/irqchip/Makefile to compile the file for ARCH_FOO.
    > What would the problem be? It's not like having the irqchip in the
    > object is optional...

    This chip is used only of one machine and only required for
    machine-special devices. If those devices are not selected, the chip
    will just waist memory.

    > I would prefer if you augment the code to use
    > IRQCHIP_DECLARE() so you can get rid of all the criss-cross
    > calls, but this init contains a comment saying that GPIO
    > has to be up before you initialize the irq_chip, can you please
    > explain why it's like that?

    This is a tertiary irq chip (primary is on CPU, secondary is GPIO). It
    triggers a GPIO interrupt if it detects one of its own.

    > Another way is to create a separate Kconfig entry for it in
    > drivers/irqchip/Kconfig if you want the set-up to be more
    > distributed, but that is usually just done when the irqchip is
    > used on more than one platform.

    Please consult, how to approach this driver using device tree. If I
    assign an "interrupts" property in the node, and the property will point
    to pxa-gpio interrupt controller using a phandle, is there a guaranty
    that my device will be probed later than pxa-gpio interrupt controller?

    Or how could that be achieved?



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