#########################################
# my dts file for the board.
#########################################

    pinctrl@01c20800 {
         led_pins_cubieboard2: led_pins@0 {
            allwinner,pins = "PB21";
            allwinner,function = "gpio_out";
            allwinner,drive = <0>;
            allwinner,pull = <0>;
         };
         driver_pins_cubieboard2: driver_pins@0 {
            allwinner,pins = "PH20";
            allwinner,function = "irq";
            allwinner,drive = <0>;
            allwinner,pull = <1>;
         };
    };

   prismlx {
      compatible = "prismlx";
      pinctrl-0 = <&driver_pins_cubieboard2>;
      interrupts-extended = <&pio 7 20>;
      interrupt-names = "rebooter";
   };

#########################################
# my platform driver probe.
#########################################

static int __init prismlx_probe(struct platform_device *pdev)
{

   irq = platform_get_irq_byname (pdev, "rebooter");
   printk (KERN_NOTICE "Got IRQ: %d\n", irq);

   if (request_irq(irq, &prismlx_interrupt, IRQF_SHARED | IRQF_RISING, "prismlx_irq", NULL)) {
      printk(KERN_ERR "prismlx-irq: cannot register IRQ %d\n", irq);
      return -EIO;
   }
   printk(KERN_INFO "prismlx-irq: registered for IRQ %d\n", irq);

   return 0;
}


################################################
# file: ./drivers/pinctrl/sunxi/pinctrl-sunxi.c
################################################

static void sunxi_pmx_set(struct pinctrl_dev *pctldev,
             unsigned pin,
             u8 config)
{
...
...
...
   printk (KERN_NOTICE "sunxi_pmx_set base %d pin %d addr %x val %08x\n",
      pctl->desc->pin_base,
      pin,
      (unsigned int) pctl->membase + sunxi_mux_reg(pin),
      val
   );

   mask = MUX_PINS_MASK << sunxi_mux_offset(pin);
   writel((val & ~mask) | config << sunxi_mux_offset(pin),
      pctl->membase + sunxi_mux_reg(pin));

   spin_unlock_irqrestore(&pctl->lock, flags);
}


static int sunxi_pinctrl_irq_request_resources(struct irq_data *d)
{
...
...
...
   printk (KERN_NOTICE "sunxi_pinctrl_irq_request_resources val %d HW %lu func %s\n",
      func->muxval,
      irqd_to_hwirq(d),
      func->name
   );

   /* Change muxing to INT mode */
   sunxi_pmx_set(pctl->pctl_dev, pctl->irq_array[d->hwirq], func->muxval);

   return 0;
}


###################################################
# printk result of insmod prismlx.ko
###################################################

[   24.526443] sunxi_pctrl_dt_node_to_map PH20 base f009c800 function gpio_in group PA0 ngroups 175
[   24.535480] of_irq_parse_one: dev=/prismlx, index=0
[   24.540439] of_irq_parse_raw:  /soc@01c00000/pinctrl@01c20800:00000007,00000014
[   24.547851] Got IRQ: 55
[   24.550327] sunxi_pinctrl_irq_request_resources val: 6 HW: 7 func->name: 'irq'
[   24.557548] sunxi_pmx_set base 0 pin 231 addr f009c8fc val 01001000
[   24.563873] dummy-irq: registered for IRQ 55