On Thu, Aug 13, 2015 at 4:11 AM, Linus Walleij [off-list ref] wrote:

On Sat, Aug 1, 2015 at 3:17 AM, Gregory Fong [off-list ref] wrote:

quoted

Uses the gpiolib irqchip helpers.  For this to work, the irq setup
function is called once per bank instead of once per device.  Note
that all known uses of this block have a BCM7120 L2 interrupt
controller as a parent.  Supports interrupts for all GPIOs.

In the IRQ handler, we check for raised IRQs for invalid GPIOs and
warn (ratelimited) if they're encountered.

Also, several drivers (e.g. gpio-keys) allow for GPIOs to be
configured as wakeup sources, and this GPIO controller supports that
through a separate interrupt path.

The de-facto standard DT property "wakeup-source" is checked, since
that indicates whether the GPIO controller hardware can wake.  Uses
the IRQCHIP_MASK_ON_SUSPEND irq_chip flag because UPG GIO doesn't have
any of its own wakeup source configuration.

Aside regarding gpiolib irqchip helpers: It wasn't obvious (to me)
that you can have multiple chained irqchips and associated IRQ domains
for a single parent IRQ, and as long as the xlate function is written
correctly, a GPIO IRQ request end up checking the correct domain and
will get associated with the correct IRQ.  What helps make this clear
is to read
  drivers/gpio/gpiolib-of.c:
   - of_gpiochip_find_and_xlate()
   - of_get_named_gpiod_flags()
  drivers/gpio/gpiolib.c:
   - gpiochip_find()

Signed-off-by: Gregory Fong <redacted>
---
v4:
- when checking parent_irq, use <= 0 or > 0 since 0 is NO_IRQ.

Patch applied, but:

quoted

+       if (of_property_read_bool(np, "interrupt-controller")) {
+               priv->parent_irq = platform_get_irq(pdev, 0);
+               if (priv->parent_irq <= 0) {
+                       dev_err(dev, "Couldn't get IRQ");
+                       return -ENOENT;
+               }
+       } else {
+               priv->parent_irq = -ENOENT;
+       }
+
        if (brcmstb_gpio_sanity_check_banks(dev, np, res))
                return -EINVAL;

This patch does not apply cleanly because the version in my
tree has INIT_LIST_HEAD(&priv->bank_list);
before the sanity check.

I applied it manually, but check that things are working right.

Your tree seems to be missing

commit 2252607d327d5219a6331b50e6ec266d56402be0
Author: Gregory Fong [off-list ref]
Date:   Wed Jun 17 18:00:40 2015 -0700

    gpio: brcmstb: fix null ptr dereference in driver remove

which you had pulled in and sent for 4.2-rc1.  It should apply cleanly
on top of that.