USB: gadget: Implement remote wakeup in ci13xxx_udc

This patch adds support for remote wakeup.  The following things
are handled:

- Process SET_FEATURE/CLEAR_FEATURE control requests sent by host
for enabling/disabling remote wakeup feature.
- Report remote wakeup enable status in response to GET_STATUS
control request.
- Implement wakeup method defined in usb_gadget_ops for initiating
remote wakeup.
- Notify gadget driver about suspend and resume.
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/ci13xxx_udc.c

@@ -1608,12 +1608,19 @@ static int _gadget_stop_activity(struct usb_gadget *gadget)
 {
 	struct usb_ep *ep;
 	struct ci13xxx    *udc = container_of(gadget, struct ci13xxx, gadget);
+	unsigned long flags;
 
 	trace("%p", gadget);
 
 	if (gadget == NULL)
 		return -EINVAL;
 
+	spin_lock_irqsave(udc->lock, flags);
+	udc->gadget.speed = USB_SPEED_UNKNOWN;
+	udc->remote_wakeup = 0;
+	udc->suspended = 0;
+	spin_unlock_irqrestore(udc->lock, flags);
+
 	/* flush all endpoints */
 	gadget_for_each_ep(ep, gadget) {
 		usb_ep_fifo_flush(ep);
@@ -1747,7 +1754,8 @@ __acquires(mEp->lock)
 	}
 
 	if ((setup->bRequestType & USB_RECIP_MASK) == USB_RECIP_DEVICE) {
-		/* TODO: D1 - Remote Wakeup; D0 - Self Powered */
+		/* Assume that device is bus powered for now. */
+		*((u16 *)req->buf) = _udc->remote_wakeup << 1;
 		retval = 0;
 	} else if ((setup->bRequestType & USB_RECIP_MASK) \
 		   == USB_RECIP_ENDPOINT) {
@@ -1913,9 +1921,9 @@ __acquires(udc->lock)
 
 		switch (req.bRequest) {
 		case USB_REQ_CLEAR_FEATURE:
-			if (type != (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
-			    le16_to_cpu(req.wValue) != USB_ENDPOINT_HALT)
-				goto delegate;
+			if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
+					le16_to_cpu(req.wValue) ==
+					USB_ENDPOINT_HALT) {
 				if (req.wLength != 0)
 					break;
 				num  = le16_to_cpu(req.wIndex);
@@ -1929,6 +1937,16 @@ __acquires(udc->lock)
 						break;
 				}
 				err = isr_setup_status_phase(udc);
+			} else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE) &&
+					le16_to_cpu(req.wValue) ==
+					USB_DEVICE_REMOTE_WAKEUP) {
+				if (req.wLength != 0)
+					break;
+				udc->remote_wakeup = 0;
+				err = isr_setup_status_phase(udc);
+			} else {
+				goto delegate;
+			}
 			break;
 		case USB_REQ_GET_STATUS:
 			if (type != (USB_DIR_IN|USB_RECIP_DEVICE)   &&
@@ -1952,9 +1970,9 @@ __acquires(udc->lock)
 			err = isr_setup_status_phase(udc);
 			break;
 		case USB_REQ_SET_FEATURE:
-			if (type != (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
-			    le16_to_cpu(req.wValue) != USB_ENDPOINT_HALT)
-				goto delegate;
+			if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
+					le16_to_cpu(req.wValue) ==
+					USB_ENDPOINT_HALT) {
 				if (req.wLength != 0)
 					break;
 				num  = le16_to_cpu(req.wIndex);
@@ -1963,9 +1981,18 @@ __acquires(udc->lock)
 				spin_unlock(udc->lock);
 				err = usb_ep_set_halt(&udc->ci13xxx_ep[num].ep);
 				spin_lock(udc->lock);
-			if (err)
+				if (!err)
+					err = isr_setup_status_phase(udc);
+			} else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE) &&
+					le16_to_cpu(req.wValue) ==
+					USB_DEVICE_REMOTE_WAKEUP) {
+				if (req.wLength != 0)
 					break;
+				udc->remote_wakeup = 1;
 				err = isr_setup_status_phase(udc);
+			} else {
+				goto delegate;
+			}
 			break;
 		default:
 delegate:
@@ -2401,6 +2428,31 @@ static int ci13xxx_vbus_session(struct usb_gadget *_gadget, int is_active)
 	return 0;
 }
 
+static int ci13xxx_wakeup(struct usb_gadget *_gadget)
+{
+	struct ci13xxx *udc = container_of(_gadget, struct ci13xxx, gadget);
+	unsigned long flags;
+	int ret = 0;
+
+	trace();
+
+	spin_lock_irqsave(udc->lock, flags);
+	if (!udc->remote_wakeup) {
+		ret = -EOPNOTSUPP;
+		dbg_trace("remote wakeup feature is not enabled\n");
+		goto out;
+	}
+	if (!hw_cread(CAP_PORTSC, PORTSC_SUSP)) {
+		ret = -EINVAL;
+		dbg_trace("port is not suspended\n");
+		goto out;
+	}
+	hw_cwrite(CAP_PORTSC, PORTSC_FPR, PORTSC_FPR);
+out:
+	spin_unlock_irqrestore(udc->lock, flags);
+	return ret;
+}
+
 /**
  * Device operations part of the API to the USB controller hardware,
  * which don't involve endpoints (or i/o)
@@ -2408,6 +2460,7 @@ static int ci13xxx_vbus_session(struct usb_gadget *_gadget, int is_active)
  */
 static const struct usb_gadget_ops usb_gadget_ops = {
 	.vbus_session	= ci13xxx_vbus_session,
+	.wakeup		= ci13xxx_wakeup,
 };
 
 /**
@@ -2650,6 +2703,12 @@ static irqreturn_t udc_irq(void)
 			isr_statistics.pci++;
 			udc->gadget.speed = hw_port_is_high_speed() ?
 				USB_SPEED_HIGH : USB_SPEED_FULL;
+			if (udc->suspended) {
+				spin_unlock(udc->lock);
+				udc->driver->resume(&udc->gadget);
+				spin_lock(udc->lock);
+				udc->suspended = 0;
+			}
 		}
 		if (USBi_UEI & intr)
 			isr_statistics.uei++;
@@ -2657,8 +2716,15 @@ static irqreturn_t udc_irq(void)
 			isr_statistics.ui++;
 			isr_tr_complete_handler(udc);
 		}
-		if (USBi_SLI & intr)
+		if (USBi_SLI & intr) {
+			if (udc->gadget.speed != USB_SPEED_UNKNOWN) {
+				udc->suspended = 1;
+				spin_unlock(udc->lock);
+				udc->driver->suspend(&udc->gadget);
+				spin_lock(udc->lock);
+			}
 			isr_statistics.sli++;
+		}
 		retval = IRQ_HANDLED;
 	} else {
 		isr_statistics.none++;

drivers/usb/gadget/ci13xxx_udc.h

@@ -128,6 +128,9 @@ struct ci13xxx {
 	u32                        ep0_dir;    /* ep0 direction */
 #define ep0out ci13xxx_ep[0]
 #define ep0in  ci13xxx_ep[16]
+	u8                         remote_wakeup; /* Is remote wakeup feature
+							enabled by the host? */
+	u8                         suspended;  /* suspended by the host */
 
 	struct usb_gadget_driver  *driver;     /* 3rd party gadget driver */
 	struct ci13xxx_udc_driver *udc_driver; /* device controller driver */
@@ -169,6 +172,7 @@ struct ci13xxx {
 #define DEVICEADDR_USBADR     (0x7FUL << 25)
 
 /* PORTSC */
+#define PORTSC_FPR            BIT(6)
 #define PORTSC_SUSP           BIT(7)
 #define PORTSC_HSP            BIT(9)
 #define PORTSC_PTC            (0x0FUL << 16)