USB: gpio_vbus: wakeup support on GPIO VBUS interrupts

We'd like to see the system waking up from the system-wide suspend
when it gets plugged-in, or the USB cable is pulled out.

Also makes it configurable via platform data 'wakeup'.

Signed-off-by: Shinya Kuribayashi <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/otg/gpio_vbus.c

···
 		goto err_otg;
 	}
 
+	device_init_wakeup(&pdev->dev, pdata->wakeup);
+
 	return 0;
 err_otg:
 	regulator_put(gpio_vbus->vbus_draw);
···
 	struct gpio_vbus_mach_info *pdata = pdev->dev.platform_data;
 	int gpio = pdata->gpio_vbus;
 
+	device_init_wakeup(&pdev->dev, 0);
 	cancel_delayed_work_sync(&gpio_vbus->work);
 	regulator_put(gpio_vbus->vbus_draw);
 
···
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int gpio_vbus_pm_suspend(struct device *dev)
+{
+	struct gpio_vbus_data *gpio_vbus = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(gpio_vbus->irq);
+
+	return 0;
+}
+
+static int gpio_vbus_pm_resume(struct device *dev)
+{
+	struct gpio_vbus_data *gpio_vbus = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(gpio_vbus->irq);
+
+	return 0;
+}
+
+static const struct dev_pm_ops gpio_vbus_dev_pm_ops = {
+	.suspend	= gpio_vbus_pm_suspend,
+	.resume		= gpio_vbus_pm_resume,
+};
+#endif
+
 /* NOTE:  the gpio-vbus device may *NOT* be hotplugged */
 
 MODULE_ALIAS("platform:gpio-vbus");
···
 	.driver = {
 		.name  = "gpio-vbus",
 		.owner = THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm = &gpio_vbus_dev_pm_ops,
+#endif
 	},
 	.remove  = __exit_p(gpio_vbus_remove),
 };

include/linux/usb/gpio_vbus.h

···
  * @gpio_pullup: optional D+ or D- pullup GPIO (else negative/invalid)
  * @gpio_vbus_inverted: true if gpio_vbus is active low
  * @gpio_pullup_inverted: true if gpio_pullup is active low
+ * @wakeup: configure gpio_vbus as a wake-up source
  *
  * The VBUS sensing GPIO should have a pulldown, which will normally be
  * part of a resistor ladder turning a 4.0V-5.25V level on VBUS into a
···
 	int gpio_pullup;
 	bool gpio_vbus_inverted;
 	bool gpio_pullup_inverted;
+	bool wakeup;
 };