USB: core: OTG Supplement Revision 2.0 updates

OTG supplement revision 2.0 spec introduces Attach Detection Protocol
(ADP) for detecting peripheral connection without applying power on
VBUS.  ADP is optional and is included in the OTG descriptor along with
SRP and HNP.

HNP polling is introduced for peripheral to notify its wish to become
host.  Host polls (GET_STATUS on DEVICE) peripheral for host_request
and suspend the bus when peripheral returns host_request TRUE.  The
spec insists the polling frequency to be in 1-2 sec range and bus
should be suspended with in 2 sec from host_request is set.

a_alt_hnp_support feature is obsolete and a_hnp_support feature is
limited to only legacy OTG B-device.  The newly introduced bcdOTG
field in the OTG descriptor is used for identifying the 2.0 compliant
B-device.

ST-Ericsson ID: 401192
ST-Ericsson Linux next: NA
ST-Ericsson FOSS-OUT ID: NA

Change-Id: I01ea82656e3ea0302613562354521ed4fae5ac5e
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Avinash Kumar <avinash.kumar@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/48747
Reviewed-by: Praveena NADAHALLY <praveen.nadahally@stericsson.com>
Reviewed-by: QATOOLS
Reviewed-by: QABUILD

6 files changed, 109 insertions, 11 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 9a56635dc19..b3948206024 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1211,6 +1211,19 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
 	 * and flush any outstanding URBs.
 	 */
 	} else {
+#ifdef CONFIG_USB_OTG
+	/* According to OTG supplement Rev 2.0 section 6.3
+	* Unless an A-device enables b_hnp_enable before entering
+	* suspend it shall also continue polling while the bus is
+	* suspended.
+	*
+	* We don't have to perform HNP polling, as we are going to
+	* enable b_hnp_enable before suspending.
+	*/
+		if (udev->bus->hnp_support &&
+			udev->portnum == udev->bus->otg_port)
+			cancel_delayed_work(&udev->bus->hnp_polling);
+#endif
 		udev->can_submit = 0;
 		for (i = 0; i < 16; ++i) {
 			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
@@ -1274,6 +1287,43 @@ static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
 	return status;
 }
 
+#ifdef CONFIG_USB_OTG
+void usb_hnp_polling_work(struct work_struct *work)
+{
+	int ret;
+	struct usb_bus *bus =
+		container_of(work, struct usb_bus, hnp_polling.work);
+	struct usb_device *udev = bus->root_hub->children[bus->otg_port - 1];
+	u8 *status = kmalloc(sizeof(*status), GFP_KERNEL);
+
+	if (!status)
+		return;
+
+	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
+		USB_REQ_GET_STATUS, USB_DIR_IN | USB_RECIP_DEVICE,
+		0, OTG_STATUS_SELECTOR, status, sizeof(*status),
+		USB_CTRL_GET_TIMEOUT);
+	if (ret < 0) {
+		/* Peripheral may not be supporting HNP polling */
+		dev_vdbg(&udev->dev, "HNP polling failed. status %d\n", ret);
+		goto out;
+	}
+
+	/* Spec says host must suspend the bus with in 2 sec. */
+	if (*status & (1 << HOST_REQUEST_FLAG)) {
+		do_unbind_rebind(udev, DO_UNBIND);
+		ret = usb_suspend_both(udev, PMSG_USER_SUSPEND);
+		if (ret)
+			dev_info(&udev->dev, "suspend failed\n");
+	} else {
+		schedule_delayed_work(&bus->hnp_polling,
+			msecs_to_jiffies(THOST_REQ_POLL));
+	}
+out:
+	kfree(status);
+}
+#endif
+
 static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
 {
 	int	w;
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 140d3e11f21..f4f78a30b1d 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -897,6 +897,9 @@ static void usb_bus_init (struct usb_bus *bus)
 	bus->bandwidth_isoc_reqs = 0;
 
 	INIT_LIST_HEAD (&bus->bus_list);
+#ifdef CONFIG_USB_OTG
+	INIT_DELAYED_WORK(&bus->hnp_polling, usb_hnp_polling_work);
+#endif
 }
 
 /*-------------------------------------------------------------------------*/
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 87c938adbc7..abb0084795c 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1693,6 +1693,12 @@ void usb_disconnect(struct usb_device **pdev)
 	dev_info(&udev->dev, "USB disconnect, device number %d\n",
 			udev->devnum);
 
+#ifdef CONFIG_USB_OTG
+	if (udev->bus->hnp_support && udev->portnum == udev->bus->otg_port) {
+		cancel_delayed_work_sync(&udev->bus->hnp_polling);
+		udev->bus->hnp_support = 0;
+	}
+#endif
 	usb_lock_device(udev);
 
 	/* Free up all the children before we remove this device */
@@ -1797,15 +1803,10 @@ static int usb_enumerate_device_otg(struct usb_device *udev)
 					(port1 == bus->otg_port)
 						? "" : "non-");
 
-				/* enable HNP before suspend, it's simpler */
-				if (port1 == bus->otg_port)
-					bus->b_hnp_enable = 1;
 				err = usb_control_msg(udev,
 					usb_sndctrlpipe(udev, 0),
 					USB_REQ_SET_FEATURE, 0,
-					bus->b_hnp_enable
-						? USB_DEVICE_B_HNP_ENABLE
-						: USB_DEVICE_A_ALT_HNP_SUPPORT,
+					USB_DEVICE_A_HNP_SUPPORT,
 					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 				if (err < 0) {
 					/* OTG MESSAGE: report errors here,
@@ -1814,24 +1815,34 @@ static int usb_enumerate_device_otg(struct usb_device *udev)
 					dev_info(&udev->dev,
 						"can't set HNP mode: %d\n",
 						err);
-					bus->b_hnp_enable = 0;
+					bus->hnp_support = 0;
 				}
 			}
 		}
 	}
 
+out:
 	if (!is_targeted(udev)) {
 
 		/* Maybe it can talk to us, though we can't talk to it.
 		 * (Includes HNP test device.)
 		 */
-		if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
+		if (udev->bus->hnp_support) {
 			err = usb_port_suspend(udev, PMSG_SUSPEND);
 			if (err < 0)
 				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
 		}
 		err = -ENOTSUPP;
 		goto fail;
+	} else if (udev->bus->hnp_support &&
+			udev->portnum == udev->bus->otg_port) {
+		/* HNP polling is introduced in OTG supplement Rev 2.0
+		 * and older devices does not support. Work is not
+		 * re-armed if device returns STALL. B-Host also performs
+		 * HNP polling.
+		 */
+		schedule_delayed_work(&udev->bus->hnp_polling,
+			msecs_to_jiffies(THOST_REQ_POLL));
 	}
 fail:
 #endif
@@ -2497,6 +2508,20 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 	if (udev->usb2_hw_lpm_enabled == 1)
 		usb_set_usb2_hardware_lpm(udev, 0);
 
+#ifdef CONFIG_USB_OTG
+	if (!udev->bus->is_b_host && udev->bus->hnp_support &&
+		udev->portnum == udev->bus->otg_port) {
+		status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+					USB_REQ_SET_FEATURE, 0,
+					USB_DEVICE_B_HNP_ENABLE,
+					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
+		if (status < 0)
+			dev_dbg(&udev->dev, "can't enable HNP on port %d, "
+					"status %d\n", port1, status);
+		else
+			udev->bus->b_hnp_enable = 1;
+		}
+#endif
 	/* see 7.1.7.6 */
 	if (hub_is_superspeed(hub->hdev))
 		status = set_port_feature(hub->hdev,
@@ -2651,6 +2676,12 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 	int		status;
 	u16		portchange, portstatus;
 
+#ifdef CONFIG_USB_OTG
+		if (!udev->bus->is_b_host && udev->bus->hnp_support &&
+					udev->portnum == udev->bus->otg_port)
+			udev->bus->b_hnp_enable = 0;
+#endif
+
 	/* Skip the initial Clear-Suspend step for a remote wakeup */
 	status = hub_port_status(hub, port1, &portstatus, &portchange);
 	if (status == 0 && !port_is_suspended(hub, portstatus))
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index 5994cef4d2d..f7962567c1b 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -78,7 +78,9 @@ static inline int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 }
 
 #endif
-
+#ifdef CONFIG_USB_OTG
+extern void usb_hnp_polling_work(struct work_struct *work);
+#endif
 #ifdef CONFIG_USB_SUSPEND
 
 extern void usb_autosuspend_device(struct usb_device *udev);
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 33488200c17..3645e63e029 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -331,6 +331,10 @@ struct usb_bus {
 	u8 otg_port;			/* 0, or number of OTG/HNP port */
 	unsigned is_b_host:1;		/* true during some HNP roleswitches */
 	unsigned b_hnp_enable:1;	/* OTG: did A-Host enable HNP? */
+#ifdef CONFIG_USB_OTG
+	unsigned hnp_support:1;         /* OTG: HNP is supported on OTG port */
+	struct delayed_work hnp_polling;/* OTG: HNP polling work */
+#endif
 	unsigned sg_tablesize;		/* 0 or largest number of sg list entries */
 
 	int devnum_next;		/* Next open device number in
diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index af21f311591..1ed2af81975 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -152,6 +152,12 @@
 
 #define USB_ENDPOINT_HALT		0	/* IN/OUT will STALL */
 
+#ifdef CONFIG_USB_OTG
+/* OTG 2.0 spec 6.2 and 6.3 sections */
+#define OTG_STATUS_SELECTOR            0xF000
+#define THOST_REQ_POLL                 1500    /* 1000 - 2000 msec */
+#define HOST_REQUEST_FLAG              0
+#endif
 /* Bit array elements as returned by the USB_REQ_GET_STATUS request. */
 #define USB_DEV_STAT_U1_ENABLED		2	/* transition into U1 state */
 #define USB_DEV_STAT_U2_ENABLED		3	/* transition into U2 state */
@@ -651,8 +657,10 @@ struct usb_qualifier_descriptor {
 struct usb_otg_descriptor {
 	__u8  bLength;
 	__u8  bDescriptorType;
-
-	__u8  bmAttributes;	/* support for HNP, SRP, etc */
+#ifdef CONFIG_USB_OTG
+	__u8  bmAttributes;     /* support for HNP, SRP, ADP etc */
+	__le16 bcdOTG;
+#endif
 } __attribute__ ((packed));
 
 /* from usb_otg_descriptor.bmAttributes */