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>

1 files changed, 57 insertions, 0 deletions

diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index 999e2f2cd2cc..d019b6c9d74d 100644
--- 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),
         },
 };