gpio: dwapb: add gpio-signaled acpi event support

This patch adds gpio-signaled acpi event support. It is used for
power button on hisilicon D02 board, an arm64 platform.

The corresponding DSDT file is defined as follows:
Device(GPI0) {
	Name(_HID, "HISI0181")
	Name(_ADR, 0)
	Name(_UID, 0)

	Name (_CRS, ResourceTemplate ()  {
		Memory32Fixed (ReadWrite, 0x802e0000, 0x10000)
		Interrupt (ResourceConsumer, Level, ActiveHigh,
		Exclusive,,,)  {344}
	})

	Device(PRTa) {
		Name (_DSD, Package () {
		Package () {
			Package () {"reg",0},
			Package () {"snps,nr-gpios",32},
		}
		})
	}

	Name (_AEI, ResourceTemplate () {
		GpioInt(Edge, ActiveLow, ExclusiveAndWake,
		PullUp, , " \\_SB.GPI0") {8}
	})

	Method (_E08, 0x0, NotSerialized) {
		Notify (\_SB.PWRB, 0x80)
	}
}
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jiang Qiu <qiujiang@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-dwapb.c

@@ -7,6 +7,7 @@
  *
  * All enquiries to support@picochip.com
  */
+#include <linux/acpi.h>
 #include <linux/gpio/driver.h>
 /* FIXME: for gpio_get_value(), replace this with direct register read */
 #include <linux/gpio.h>
@@ -27,6 +28,8 @@
 #include <linux/platform_data/gpio-dwapb.h>
 #include <linux/slab.h>
 
+#include "gpiolib.h"
+
 #define GPIO_SWPORTA_DR		0x00
 #define GPIO_SWPORTA_DDR	0x04
 #define GPIO_SWPORTB_DR		0x0c
@@ -435,6 +438,10 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
 	else
 		port->is_registered = true;
 
+	/* Add GPIO-signaled ACPI event support */
+	if (pp->irq)
+		acpi_gpiochip_request_interrupts(&port->gc);
+
 	return err;
 }
 
@@ -502,6 +509,9 @@ dwapb_gpio_get_pdata(struct device *dev)
 				dev_warn(dev, "no irq for port%d\n", pp->idx);
 		}
 
+		if (has_acpi_companion(dev) && pp->idx == 0)
+			pp->irq = platform_get_irq(to_platform_device(dev), 0);
+
 		pp->irq_shared	= false;
 		pp->gpio_base	= -1;
 	}
@@ -576,6 +586,12 @@ static const struct of_device_id dwapb_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, dwapb_of_match);
 
+static const struct acpi_device_id dwapb_acpi_match[] = {
+	{"HISI0181", 0},
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, dwapb_acpi_match);
+
 #ifdef CONFIG_PM_SLEEP
 static int dwapb_gpio_suspend(struct device *dev)
 {
@@ -670,6 +686,7 @@ static struct platform_driver dwapb_gpio_driver = {
 		.name	= "gpio-dwapb",
 		.pm	= &dwapb_gpio_pm_ops,
 		.of_match_table = of_match_ptr(dwapb_of_match),
+		.acpi_match_table = ACPI_PTR(dwapb_acpi_match),
 	},
 	.probe		= dwapb_gpio_probe,
 	.remove		= dwapb_gpio_remove,