• Gregory Fong's avatar
    gpio: brcmstb: Add interrupt and wakeup source support · 19a7b694
    Gregory Fong authored
    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: default avatarGregory Fong <gregory.0xf0@gmail.com>
    Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
    Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
    19a7b694
Kconfig 28.4 KB