[PATCH v4 2/4] gpio: brcmstb: Add interrupt and wakeup source support

[Gregory Fong]

On Thu, Aug 13, 2015 at 4:11 AM, Linus Walleij <linus.walleij at linaro.org> wrote:
> On Sat, Aug 1, 2015 at 3:17 AM, Gregory Fong <gregory.0xf0 at gmail.com> wrote:
>
>> 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 <gregory.0xf0 at gmail.com>
>> ---
>> v4:
>> - when checking parent_irq, use <= 0 or > 0 since 0 is NO_IRQ.
>
> Patch applied, but:
>
>
>> +       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 <gregory.0xf0 at gmail.com>
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.