usb: gadget: atmel_usba_udc: Add suspend/resume with wakeup support

This patch add suspend/resume with wakeup support for Atmel USBA.

On suspend: We stay continuously clocked if Vbus signal is not
available. If Vbus signal is available we set the Vbus signal as a wake
up source then we stop the USBA itself and all clocks used by USBA.

On resume: We recover clocks and USBA if we stopped them. If a device is
currently connected at resume time we enable the controller.

Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index 999e2f2cd2cc4343bf769964f1eeaf31917032f1..d019b6c9d74dae761bc8a5a41a41b2ec035bef1b 100644 (file)
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -2177,6 +2177,7 @@ static int usba_udc_probe(struct platform_device *pdev)
        ret = usb_add_gadget_udc(&pdev->dev, &udc->gadget);
        if (ret)
                return ret;
+       device_init_wakeup(&pdev->dev, 1);
 
        usba_init_debugfs(udc);
        for (i = 1; i < udc->num_ep; i++)
@@ -2192,6 +2193,7 @@ static int __exit usba_udc_remove(struct platform_device *pdev)
 
        udc = platform_get_drvdata(pdev);
 
+       device_init_wakeup(&pdev->dev, 0);
        usb_del_gadget_udc(&udc->gadget);
 
        for (i = 1; i < udc->num_ep; i++)
@@ -2201,10 +2203,65 @@ static int __exit usba_udc_remove(struct platform_device *pdev)
        return 0;
 }
 
+#ifdef CONFIG_PM
+static int usba_udc_suspend(struct device *dev)
+{
+       struct usba_udc *udc = dev_get_drvdata(dev);
+
+       /* Not started */
+       if (!udc->driver)
+               return 0;
+
+       mutex_lock(&udc->vbus_mutex);
+
+       if (!device_may_wakeup(dev)) {
+               usba_stop(udc);
+               goto out;
+       }
+
+       /*
+        * Device may wake up. We stay clocked if we failed
+        * to request vbus irq, assuming always on.
+        */
+       if (gpio_is_valid(udc->vbus_pin)) {
+               usba_stop(udc);
+               enable_irq_wake(gpio_to_irq(udc->vbus_pin));
+       }
+
+out:
+       mutex_unlock(&udc->vbus_mutex);
+       return 0;
+}
+
+static int usba_udc_resume(struct device *dev)
+{
+       struct usba_udc *udc = dev_get_drvdata(dev);
+
+       /* Not started */
+       if (!udc->driver)
+               return 0;
+
+       if (device_may_wakeup(dev) && gpio_is_valid(udc->vbus_pin))
+               disable_irq_wake(gpio_to_irq(udc->vbus_pin));
+
+       /* If Vbus is present, enable the controller and wait for reset */
+       mutex_lock(&udc->vbus_mutex);
+       udc->vbus_prev = vbus_is_present(udc);
+       if (udc->vbus_prev)
+               usba_start(udc);
+       mutex_unlock(&udc->vbus_mutex);
+
+       return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(usba_udc_pm_ops, usba_udc_suspend, usba_udc_resume);
+
 static struct platform_driver udc_driver = {
        .remove         = __exit_p(usba_udc_remove),
        .driver         = {
                .name           = "atmel_usba_udc",
+               .pm             = &usba_udc_pm_ops,
                .of_match_table = of_match_ptr(atmel_udc_dt_ids),
        },
 };