usb: dwc3: otg: Add support for ending HNP session

As a part of sucessful HNP session both A-Device and
B-Device swaps their roles from A-Device: Host->Peripheral
and B-Device: Peripheral->Host. Once the B-Device is done
as Host, the HNP session should be ended to restore to their
previous roles i.e, A-Device: Peripheral->Host and B-Device:
Host->Peripheral. This patch adds a sysfs entry which will
end the HNP session and restore to their original roles.

Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/drivers/usb/dwc3/otg.c b/drivers/usb/dwc3/otg.c
index e72a05cf74abaf5c4eb9111f0de5d85c50d69837..4c844a52953efee087e5af5417d0d90c0c1cecc3 100644 (file)
--- a/drivers/usb/dwc3/otg.c
+++ b/drivers/usb/dwc3/otg.c
@@ -991,16 +991,19 @@ static enum usb_otg_state do_a_peripheral(struct dwc3_otg *otg)
 {
        int rc;
        u32 otg_mask;
+       u32 user_mask;
        u32 otg_events = 0;
+       u32 user_events = 0;
 
        otg_dbg(otg, "");
        otg_mask = OEVT_CONN_ID_STS_CHNG_EVNT |
                OEVT_A_DEV_SESS_END_DET_EVNT |
                OEVT_A_DEV_B_DEV_HOST_END_EVNT;
+       user_mask = USER_HNP_END_SESSION;
 
        rc = sleep_until_event(otg,
-                       otg_mask, 0,
-                       &otg_events, NULL, 0);
+                       otg_mask, user_mask,
+                       &otg_events, &user_events, 0);
        if (rc < 0)
                return OTG_STATE_UNDEFINED;
 
@@ -1015,6 +1018,9 @@ static enum usb_otg_state do_a_peripheral(struct dwc3_otg *otg)
        } else if (otg_events & OEVT_A_DEV_B_DEV_HOST_END_EVNT) {
                otg_dbg(otg, "OEVT_A_DEV_B_DEV_HOST_END_EVNT\n");
                return OTG_STATE_A_WAIT_VRISE;
+       } else if (user_events & USER_HNP_END_SESSION) {
+               otg_dbg(otg, "USER_HNP_END_SESSION\n");
+               return OTG_STATE_A_WAIT_VRISE;
        }
 
        return OTG_STATE_UNDEFINED;
@@ -1145,7 +1151,7 @@ static enum usb_otg_state do_b_wait_acon(struct dwc3_otg *otg)
                OEVT_B_DEV_B_HOST_END_EVNT |
                OEVT_B_DEV_VBUS_CHNG_EVNT |
                OEVT_HOST_ROLE_REQ_INIT_EVNT;
-       user_mask = USER_A_CONN_EVENT;
+       user_mask = USER_A_CONN_EVENT | USER_HNP_END_SESSION;
 
 again:
        rc = sleep_until_event(otg,
@@ -1173,6 +1179,9 @@ again:
        } else if (user_events & USER_A_CONN_EVENT) {
                otg_dbg(otg, "A-device connected\n");
                return OTG_STATE_B_HOST;
+       } else if (user_events & USER_HNP_END_SESSION) {
+               otg_dbg(otg, "USER_HNP_END_SESSION\n");
+               return OTG_STATE_B_PERIPHERAL;
        }
 
        /* Invalid state */
@@ -1193,6 +1202,7 @@ static enum usb_otg_state do_b_host(struct dwc3_otg *otg)
                OEVT_B_DEV_B_HOST_END_EVNT |
                OEVT_B_DEV_VBUS_CHNG_EVNT |
                OEVT_HOST_ROLE_REQ_INIT_EVNT;
+       user_mask = USER_HNP_END_SESSION;
 
 again:
        rc = sleep_until_event(otg,
@@ -1217,6 +1227,9 @@ again:
                        otg_dbg(otg, "Session not valid\n");
                        return OTG_STATE_B_IDLE;
                }
+       } else if (user_events & USER_HNP_END_SESSION) {
+               otg_dbg(otg, "USER_HNP_END_SESSION\n");
+               return OTG_STATE_B_PERIPHERAL;
        }
 
        /* Invalid state */
@@ -1975,6 +1988,39 @@ static ssize_t store_hnp(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR(hnp, 0220, NULL, store_hnp);
 
+static ssize_t store_hnp_end(struct device *dev, struct device_attribute *attr,
+                            const char *buf, size_t count)
+{
+       struct usb_phy *phy;
+       struct usb_otg *otg;
+       unsigned long flags;
+       struct dwc3_otg *dwc_otg;
+
+       phy = usb_get_phy(USB_PHY_TYPE_USB3);
+       if (IS_ERR(phy) || !phy) {
+               if (!IS_ERR(phy))
+                       usb_put_phy(phy);
+               return count;
+       }
+
+       otg = phy->otg;
+       if (!otg) {
+               usb_put_phy(phy);
+               return count;
+       }
+
+       dwc_otg = otg_to_dwc3_otg(otg);
+
+       spin_lock_irqsave(&dwc_otg->lock, flags);
+       dwc_otg->user_events |= USER_HNP_END_SESSION;
+       wakeup_main_thread(dwc_otg);
+       spin_unlock_irqrestore(&dwc_otg->lock, flags);
+
+       usb_put_phy(phy);
+       return count;
+}
+static DEVICE_ATTR(hnp_end, 0220, NULL, store_hnp_end);
+
 static ssize_t store_a_hnp_reqd(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
 {
@@ -2007,6 +2053,7 @@ void dwc_usb3_remove_dev_files(struct device *dev)
        device_remove_file(dev, &dev_attr_end);
        device_remove_file(dev, &dev_attr_srp);
        device_remove_file(dev, &dev_attr_hnp);
+       device_remove_file(dev, &dev_attr_hnp_end);
 }
 
 int dwc3_otg_create_dev_files(struct device *dev)
@@ -2017,6 +2064,10 @@ int dwc3_otg_create_dev_files(struct device *dev)
        if (retval)
                goto fail;
 
+       retval = device_create_file(dev, &dev_attr_hnp_end);
+       if (retval)
+               goto fail;
+
        retval = device_create_file(dev, &dev_attr_srp);
        if (retval)
                goto fail;