On Fri, Nov 8, 2013 at 11:11 AM, Prabhakar Lad
<prabhakar.csengg@xxxxxxxxx> wrote:
> From: "Lad, Prabhakar" <prabhakar.csengg@xxxxxxxxx>
>
> This patch converts the davinci gpio driver to use irqdomain
> support.
>
> Signed-off-by: Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx>
(...)
> @@ -282,8 +283,7 @@ gpio_irq_handler(unsigned irq, struct irq_desc *desc)
> desc->irq_data.chip->irq_ack(&desc->irq_data);
> while (1) {
> u32 status;
> - int n;
> - int res;
> + int bit;
Why is this an int? I think u8 would suffice.
> /* now demux them to the right lowlevel handler */
> - n = d->irq_base;
> - if (irq & 1) {
> - n += 16;
> - status >>= 16;
> - }
> -
> while (status) {
> - res = ffs(status);
> - n += res;
> - generic_handle_irq(n - 1);
> - status >>= res;
> + bit = __ffs(status);
> + status &= ~(1 << bit);
> + generic_handle_irq(irq_find_mapping(d->irq_domain,
> + bit));
This is a nice hunk of the patch.
I would use <linux/bitops.h> and do:
status &= ~BIT(bit);
> @@ -313,10 +307,7 @@ static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
> {
> struct davinci_gpio_controller *d = chip2controller(chip);
>
> - if (d->irq_base >= 0)
> - return d->irq_base + offset;
> - else
> - return -ENODEV;
> + return irq_create_mapping(d->irq_domain, offset);
> }
I think we recently established that map creating cannot be done
in gpio_to_irq* functions as that will not work properly if you request
an IRQ from device tree without first obtaining the IRQ from the GPIO
number with this function.
Instead call irq_create_mapping() on *all* used IRQ lines in the
probe function and use irq_find_mapping() here too.
> + for (gpio = 0, bank = 0; gpio < ngpio; bank++, bank_irq++, gpio += 16) {
> /* disabled by default, enabled only as needed */
> g = gpio2regs(gpio);
> writel(~0, &g->clr_falling);
> @@ -467,14 +483,6 @@ static int davinci_gpio_irq_setup(struct platform_device *pdev)
> */
> irq_set_handler_data(bank_irq, &chips[gpio / 32]);
So for example here you could call iurq_create_mapping();
Also: please write a patch that marks the IRQ lines.
Call gpio_lock_as_irq(*gpio_chip, offset); in the
irqchip startup/shutdown functions. (Can be a separate
patch.)
Yours,
Linus Walleij
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