[RFC v2 0/4] USB core changes for supporting OTG on MSM SoC

[RFC v2 0/4] USB core changes for supporting OTG on MSM SoC

[Pavankumar Kondeti]

This patch series adds OTG 2.0 enhancements and misc changes
required for supporting SRP & HNP in MSM OTG driver.  As these
patches modify the USB core code, I would like to receive
feedback before posting driver patches. The driver patches are
available at
https://www.codeaurora.org/gitweb/quic/la/?p=kernel/msm.git;a=commitdiff;h=05535a995e9eb34c3c41d874d09955a443008cd5

Change log from V1
1. Removed unnecessary #ifdef CONFIG_USB_OTG references
2. OTG Kconfig change is removed from this patch series
3. Implemented Alan Stern's suggestions in hnp_polling_work
	a. reschedule work when kmalloc fails
	b. clear do_remote_wakeup flag before suspending

Pavankumar Kondeti (4):
  USB: core: OTG Supplement Revision 2.0 updates
  USB: gadget: OTG supplement revision 2.0 updates
  USB: EHCI: Notify HCD about HNP enabled port suspend
  USB: Eliminate delays involved in root hub initialization during HNP

 .../testing/sysfs-devices-platform-_UDC_-gadget    |   14 ++++
 drivers/usb/core/driver.c                          |   53 ++++++++++++++
 drivers/usb/core/hcd.c                             |    3 +
 drivers/usb/core/hub.c                             |   75 +++++++++++++++++---
 drivers/usb/core/usb.h                             |    8 ++
 drivers/usb/gadget/composite.c                     |   23 ++++++
 drivers/usb/gadget/zero.c                          |    3 +
 drivers/usb/host/ehci-hub.c                        |   11 +++
 drivers/usb/host/ehci.h                            |    2 +
 include/linux/usb.h                                |    2 +
 include/linux/usb/ch9.h                            |   11 +++-
 include/linux/usb/gadget.h                         |   21 ++++++
 12 files changed, 214 insertions(+), 12 deletions(-)

--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

[RFC v2 1/4] USB: core: OTG Supplement Revision 2.0 updates

[Pavankumar Kondeti]

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 within 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.

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
---
 drivers/usb/core/driver.c |   53 ++++++++++++++++++++++++++++++++++++
 drivers/usb/core/hcd.c    |    1 +
 drivers/usb/core/hub.c    |   66 ++++++++++++++++++++++++++++++++++++++-------
 drivers/usb/core/usb.h    |    8 +++++
 include/linux/usb.h       |    2 +
 include/linux/usb/ch9.h   |   11 ++++++-
 6 files changed, 129 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index b9278a1..baada06 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1207,6 +1207,18 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
 	 * and flush any outstanding URBs.
 	 */
 	} else {
+		/* 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);
+
 		udev->can_submit = 0;
 		for (i = 0; i < 16; ++i) {
 			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
@@ -1270,6 +1282,47 @@ 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) {
+		schedule_delayed_work(&bus->hnp_polling,
+			msecs_to_jiffies(THOST_REQ_POLL));
+		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);
+		udev->do_remote_wakeup = 0;
+		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 e70aeaf..5dd59e9 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -869,6 +869,7 @@ static void usb_bus_init (struct usb_bus *bus)
 	bus->bandwidth_isoc_reqs = 0;
 
 	INIT_LIST_HEAD (&bus->bus_list);
+	INIT_DELAYED_WORK(&bus->hnp_polling, usb_hnp_polling_work);
 }
 
 /*-------------------------------------------------------------------------*/
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b98efae..ac79fd5 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1581,6 +1581,11 @@ void usb_disconnect(struct usb_device **pdev)
 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
 	dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
 
+	if (udev->bus->hnp_support && udev->portnum == udev->bus->otg_port) {
+		cancel_delayed_work_sync(&udev->bus->hnp_polling);
+		udev->bus->hnp_support = 0;
+	}
+
 	usb_lock_device(udev);
 
 	/* Free up all the children before we remove this device */
@@ -1685,15 +1690,31 @@ 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;
+				/* a_alt_hnp_support is obsoleted */
+				if (port1 != bus->otg_port)
+					goto fail;
+
+				bus->hnp_support = 1;
+
+				/* a_hnp_support is not required for devices
+				 * compliant to revision 2.0 or subsequent
+				 * versions.
+				 */
+				if (desc->bLength == sizeof(*desc) &&
+					le16_to_cpu(desc->bcdOTG) >= 0x0200)
+					goto out;
+
+				/* Legacy B-device i.e compliant to spec
+				 * revision 1.3 expect A-device to set
+				 * a_hnp_support or b_hnp_enable before
+				 * selecting configuration. b_hnp_enable
+				 * is set before suspending the port.
+				 */
+
 				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,
@@ -1702,24 +1723,32 @@ 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
@@ -2210,6 +2239,19 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 		}
 	}
 
+	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;
+	}
+
 	/* see 7.1.7.6 */
 	status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
 	if (status) {
@@ -2353,6 +2395,10 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 	int		status;
 	u16		portchange, portstatus;
 
+	if (!udev->bus->is_b_host && udev->bus->hnp_support &&
+			udev->portnum == udev->bus->otg_port)
+		udev->bus->b_hnp_enable = 0;
+
 	/* Skip the initial Clear-Suspend step for a remote wakeup */
 	status = hub_port_status(hub, port1, &portstatus, &portchange);
 	if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index b975450..ffa16e1 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -72,6 +72,14 @@ 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);
+#else
+static inline 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 5ee2223..4ddb8d1 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -317,6 +317,8 @@ 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? */
+	unsigned hnp_support:1;         /* OTG: HNP is supported on OTG port */
+	struct delayed_work hnp_polling;/* OTG: HNP polling work */
 	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 ab46194..504f8b5 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -151,6 +151,11 @@
 #define USB_DEV_STAT_U2_ENABLED		3	/* transition into U2 state */
 #define USB_DEV_STAT_LTM_ENABLED	4	/* Latency tolerance messages */
 
+/* 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
+
 /**
  * struct usb_ctrlrequest - SETUP data for a USB device control request
  * @bRequestType: matches the USB bmRequestType field
@@ -605,17 +610,19 @@ struct usb_qualifier_descriptor {
 
 /*-------------------------------------------------------------------------*/
 
-/* USB_DT_OTG (from OTG 1.0a supplement) */
+/* USB_DT_OTG (from OTG 2.0 supplement) */
 struct usb_otg_descriptor {
 	__u8  bLength;
 	__u8  bDescriptorType;
 
-	__u8  bmAttributes;	/* support for HNP, SRP, etc */
+	__u8  bmAttributes;	/* support for HNP, SRP, ADP etc */
+	__le16 bcdOTG;
 } __attribute__ ((packed));
 
 /* from usb_otg_descriptor.bmAttributes */
 #define USB_OTG_SRP		(1 << 0)
 #define USB_OTG_HNP		(1 << 1)	/* swap host/device roles */
+#define USB_OTG_ADP		(1 << 2)	/* Attach detection protocol */
 
 /*-------------------------------------------------------------------------*/
 
-- 
1.7.1

--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

[RFC v2 2/4] USB: gadget: OTG supplement revision 2.0 updates

[Pavankumar Kondeti]

Introduce otg_version field in usb_gadget struct.  UDC can
advertise OTG spec version compatibility by setting otg_version
field appropriately.  Gadget drivers fill the bcdOTG field in
OTG descriptor based on UDC's OTG version.

Add sysfs file for host_request and UDC returns the same when
HNP polling request arrives from the host.

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
---
This patch only modifies gadget zero. But the final patch will
modify all the gadget drivers.

 .../testing/sysfs-devices-platform-_UDC_-gadget    |   14 ++++++++++++
 drivers/usb/gadget/composite.c                     |   23 ++++++++++++++++++++
 drivers/usb/gadget/zero.c                          |    3 ++
 include/linux/usb/gadget.h                         |   21 ++++++++++++++++++
 4 files changed, 61 insertions(+), 0 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-devices-platform-_UDC_-gadget b/Documentation/ABI/testing/sysfs-devices-platform-_UDC_-gadget
index d548eaa..9c622e4 100644
--- a/Documentation/ABI/testing/sysfs-devices-platform-_UDC_-gadget
+++ b/Documentation/ABI/testing/sysfs-devices-platform-_UDC_-gadget
@@ -19,3 +19,17 @@ Description:
 		Possible values are:
 			1 -> ignore the FUA flag
 			0 -> obey the FUA flag
+
+What:		/sys/devices/platform/_UDC_/gadget/host_request
+Date:		December 2010
+Contact:	Pavan Kondeti <pkondeti@codeaurora.org>
+Description:
+		OTG 2.0 compliant host keeps polling OTG2.0 peripheral
+		for host role. Set host_request flag, which tells host
+		to give up the host role to peripheral.
+
+		1 -> host role is requested
+		0 -> no effect (automatically cleared upon reset/disconnect)
+
+		(_UDC_ is the name of the USB Device Controller driver)
+
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 77cabcb..f3a2023 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -978,6 +978,7 @@ static void composite_disconnect(struct usb_gadget *gadget)
 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
 	unsigned long			flags;
 
+	gadget->host_request = 0;
 	/* REVISIT:  should we have config and device level
 	 * disconnect callbacks?
 	 */
@@ -1003,6 +1004,23 @@ static ssize_t composite_show_suspended(struct device *dev,
 
 static DEVICE_ATTR(suspended, 0444, composite_show_suspended, NULL);
 
+static ssize_t composite_set_host_request(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
+	int value;
+
+	if (sscanf(buf, "%d", &value) != 1)
+		return -EINVAL;
+
+	gadget->host_request = !!value;
+	return count;
+
+}
+
+static DEVICE_ATTR(host_request, S_IWUSR, NULL, composite_set_host_request);
+
 static void
 composite_unbind(struct usb_gadget *gadget)
 {
@@ -1047,6 +1065,7 @@ composite_unbind(struct usb_gadget *gadget)
 		kfree(cdev->req->buf);
 		usb_ep_free_request(gadget->ep0, cdev->req);
 	}
+	device_remove_file(&gadget->dev, &dev_attr_host_request);
 	device_remove_file(&gadget->dev, &dev_attr_suspended);
 	kfree(cdev);
 	set_gadget_data(gadget, NULL);
@@ -1158,6 +1177,10 @@ static int composite_bind(struct usb_gadget *gadget)
 	if (status)
 		goto fail;
 
+	status = device_create_file(&gadget->dev, &dev_attr_host_request);
+	if (status)
+		DBG(cdev, "unable to create host_request sysfs file\n");
+
 	INFO(cdev, "%s ready\n", composite->name);
 	return 0;
 
diff --git a/drivers/usb/gadget/zero.c b/drivers/usb/gadget/zero.c
index 6d16db9..b4fb719 100644
--- a/drivers/usb/gadget/zero.c
+++ b/drivers/usb/gadget/zero.c
@@ -293,6 +293,9 @@ static int __init zero_bind(struct usb_composite_dev *cdev)
 
 	setup_timer(&autoresume_timer, zero_autoresume, (unsigned long) cdev);
 
+	if (gadget_is_otg2(cdev->gadget))
+		otg_descriptor.bcdOTG = __constant_cpu_to_le16(0x0200);
+
 	/* Register primary, then secondary configuration.  Note that
 	 * SH3 only allows one config...
 	 */
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 006412c..b891257 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -443,6 +443,8 @@ struct usb_gadget_ops {
  *	operation.  If it does, the gadget driver must also support both.
  * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
  *	gadget driver must provide a USB OTG descriptor.
+ * @otg_version: UDC OTG version based on which gadget driver fills the
+ *	bcdOTG field in a USB OTG descriptor.
  * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
  *	is in the Mini-AB jack, and HNP has been used to switch roles
  *	so that the "A" device currently acts as A-Peripheral, not A-Host.
@@ -452,6 +454,7 @@ struct usb_gadget_ops {
  *	only supports HNP on a different root port.
  * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
  *	enabled HNP support.
+ * @host_request: A Flag, indicating that user wishes to take the host role.
  * @name: Identifies the controller hardware type.  Used in diagnostics
  *	and sometimes configuration.
  * @dev: Driver model state for this abstract device.
@@ -482,10 +485,14 @@ struct usb_gadget {
 	enum usb_device_speed		speed;
 	unsigned			is_dualspeed:1;
 	unsigned			is_otg:1;
+	u16				otg_version;
+#define	UDC_OTG1	0x0000
+#define	UDC_OTG2	0x0001
 	unsigned			is_a_peripheral:1;
 	unsigned			b_hnp_enable:1;
 	unsigned			a_hnp_support:1;
 	unsigned			a_alt_hnp_support:1;
+	unsigned			host_request:1;
 	const char			*name;
 	struct device			dev;
 };
@@ -537,6 +544,20 @@ static inline int gadget_is_otg(struct usb_gadget *g)
 }
 
 /**
+ * gadget_is_otg2 - return true if UDC is compliant to OTG 2.0
+ * @g: controller that might have a Mini-AB/Micro-AB connector
+ *
+ */
+static inline int gadget_is_otg2(struct usb_gadget *g)
+{
+#ifdef CONFIG_USB_OTG
+	return g->otg_version && UDC_OTG2;
+#else
+	return 0;
+#endif
+}
+
+/**
  * usb_gadget_frame_number - returns the current frame number
  * @gadget: controller that reports the frame number
  *
-- 
1.7.1

--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

[RFC v2 3/4] USB: EHCI: Notify HCD about HNP enabled port suspend

[Pavankumar Kondeti]

Introduce start_hnp callback function for HCD to receive notification
from EHCI core that HNP enabled port is suspended.  HCD may initiate
HNP or notify the same to OTG via otg_start_hnp().

This patch is inspired by "USB: Hook start_hnp into ohci struct"
(e8b24450).

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
---
 drivers/usb/host/ehci-hub.c |   11 +++++++++++
 drivers/usb/host/ehci.h     |    2 ++
 2 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 796ea0c..65bf104 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -1018,6 +1018,17 @@ static int ehci_hub_control (
 					|| (temp & PORT_RESET) != 0)
 				goto error;
 
+#ifdef	CONFIG_USB_OTG
+			if (hcd->self.otg_port == (wIndex + 1) &&
+					hcd->self.b_hnp_enable &&
+					ehci->start_hnp) {
+				ehci_writel(ehci, temp | PORT_SUSPEND,
+						status_reg);
+				set_bit(wIndex, &ehci->suspended_ports);
+				ehci->start_hnp(ehci);
+				break;
+			}
+#endif
 			/* After above check the port must be connected.
 			 * Set appropriate bit thus could put phy into low power
 			 * mode if we have hostpc feature
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index fd1c53d..a4989f2 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -122,6 +122,8 @@ struct ehci_hcd {			/* one per controller */
 	ktime_t			last_periodic_enable;
 	u32			command;
 
+	void (*start_hnp)(struct ehci_hcd *ehci);
+
 	/* SILICON QUIRKS */
 	unsigned		no_selective_suspend:1;
 	unsigned		has_fsl_port_bug:1; /* FreeScale */
-- 
1.7.1

--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

[RFC v2 4/4] USB: Eliminate delays involved in root hub initialization during HNP

[Pavankumar Kondeti]

Some USB controllers have common resources (IRQ, register address
space) for Host, Peripheral and OTG.  So HCD is added only before
entering into Host mode.  Root hub initialization is done in
different steps to decrease boot up time.  But this makes B-device
difficult to meet HNP timings.  Hence eliminate delays involved in
root hub initialization for B-host.

This patch also marks hnp_supported flag TRUE for B-host while
registering the bus.

Change-Id: I821775e8c90bd71a7abbe17176f189664a1841e1
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
---
 drivers/usb/core/hcd.c |    2 ++
 drivers/usb/core/hub.c |    9 +++++++++
 2 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 5dd59e9..07e6903 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -900,6 +900,8 @@ static int usb_register_bus(struct usb_bus *bus)
 	list_add (&bus->bus_list, &usb_bus_list);
 	mutex_unlock(&usb_bus_list_lock);
 
+	if (bus->is_b_host)
+		bus->hnp_support = 1;
 	usb_notify_add_bus(bus);
 
 	dev_info (bus->controller, "new USB bus registered, assigned bus "
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index ac79fd5..2df61ba 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -680,6 +680,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 	int status;
 	bool need_debounce_delay = false;
 	unsigned delay;
+	bool hnp_in_progress = hdev->bus->is_b_host && (type == HUB_INIT);
 
 	/* Continue a partial initialization */
 	if (type == HUB_INIT2)
@@ -706,6 +707,8 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 		 */
 		if (type == HUB_INIT) {
 			delay = hub_power_on(hub, false);
+			if (hnp_in_progress)
+				goto init2;
 			PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
 			schedule_delayed_work(&hub->init_work,
 					msecs_to_jiffies(delay));
@@ -811,6 +814,9 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 		}
 	}
 
+		if (hnp_in_progress)
+			goto init3;
+
 	/* If no port-status-change flags were set, we don't need any
 	 * debouncing.  If flags were set we can try to debounce the
 	 * ports all at once right now, instead of letting khubd do them
@@ -844,6 +850,9 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 	/* Scan all ports that need attention */
 	kick_khubd(hub);
 
+	if (hnp_in_progress)
+		return;
+
 	/* Allow autosuspend if it was suppressed */
 	if (type <= HUB_INIT3)
 		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
-- 
1.7.1

--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

Re: [RFC v2 4/4] USB: Eliminate delays involved in root hub initialization during HNP

[Sergei Shtylyov]

Hello.

On 16-12-2010 14:09, Pavankumar Kondeti wrote:

> Some USB controllers have common resources (IRQ, register address
> space) for Host, Peripheral and OTG.  So HCD is added only before
> entering into Host mode.  Root hub initialization is done in
> different steps to decrease boot up time.  But this makes B-device
> difficult to meet HNP timings.  Hence eliminate delays involved in
> root hub initialization for B-host.

> This patch also marks hnp_supported flag TRUE for B-host while
> registering the bus.

> Change-Id: I821775e8c90bd71a7abbe17176f189664a1841e1
> Signed-off-by: Pavankumar Kondeti<pkondeti@codeaurora.org>
[...]

> index ac79fd5..2df61ba 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -680,6 +680,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
>   	int status;
>   	bool need_debounce_delay = false;
>   	unsigned delay;
> +	bool hnp_in_progress = hdev->bus->is_b_host&&  (type == HUB_INIT);

    Parens here are not necessary.

WBR, Sergei

Re: [RFC v2 4/4] USB: Eliminate delays involved in root hub initialization during HNP

[Felipe Balbi]

On Thu, Dec 16, 2010 at 03:39:35PM +0300, Sergei Shtylyov wrote:
>Hello.
>
>On 16-12-2010 14:09, Pavankumar Kondeti wrote:
>
>>Some USB controllers have common resources (IRQ, register address
>>space) for Host, Peripheral and OTG.  So HCD is added only before
>>entering into Host mode.  Root hub initialization is done in
>>different steps to decrease boot up time.  But this makes B-device
>>difficult to meet HNP timings.  Hence eliminate delays involved in
>>root hub initialization for B-host.
>
>>This patch also marks hnp_supported flag TRUE for B-host while
>>registering the bus.
>
>>Change-Id: I821775e8c90bd71a7abbe17176f189664a1841e1
>>Signed-off-by: Pavankumar Kondeti<pkondeti@codeaurora.org>
>[...]
>
>>index ac79fd5..2df61ba 100644
>>--- a/drivers/usb/core/hub.c
>>+++ b/drivers/usb/core/hub.c
>>@@ -680,6 +680,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
>>  	int status;
>>  	bool need_debounce_delay = false;
>>  	unsigned delay;
>>+	bool hnp_in_progress = hdev->bus->is_b_host&&  (type == HUB_INIT);
>
>   Parens here are not necessary.

there's also a missing space before &&

-- 
balbi

Re: [RFC v2 4/4] USB: Eliminate delays involved in root hub initialization during HNP

[Pavan Kondeti]

On 12/16/2010 6:37 PM, Felipe Balbi wrote:
> On Thu, Dec 16, 2010 at 03:39:35PM +0300, Sergei Shtylyov wrote:
>> Hello.
>>
>> On 16-12-2010 14:09, Pavankumar Kondeti wrote:
>>
>>> Some USB controllers have common resources (IRQ, register address
>>> space) for Host, Peripheral and OTG.  So HCD is added only before
>>> entering into Host mode.  Root hub initialization is done in
>>> different steps to decrease boot up time.  But this makes B-device
>>> difficult to meet HNP timings.  Hence eliminate delays involved in
>>> root hub initialization for B-host.
>>
>>> This patch also marks hnp_supported flag TRUE for B-host while
>>> registering the bus.
>>
>>> Change-Id: I821775e8c90bd71a7abbe17176f189664a1841e1
>>> Signed-off-by: Pavankumar Kondeti<pkondeti@codeaurora.org>
>> [...]
>>
>>> index ac79fd5..2df61ba 100644
>>> --- a/drivers/usb/core/hub.c
>>> +++ b/drivers/usb/core/hub.c
>>> @@ -680,6 +680,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
>>>  	int status;
>>>  	bool need_debounce_delay = false;
>>>  	unsigned delay;
>>> +	bool hnp_in_progress = hdev->bus->is_b_host&&  (type == HUB_INIT);
>>
>>   Parens here are not necessary.
> 
> there's also a missing space before &&
> 
There is one. Please see my original patch. I am not sure why it is
missing in Sergei's reply.

Thanks,
Pavan

-- 
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

Re: [RFC v2 4/4] USB: Eliminate delays involved in root hub initialization during HNP

[Sergei Shtylyov]

On 16-12-2010 16:07, Felipe Balbi wrote:

>>> Some USB controllers have common resources (IRQ, register address
>>> space) for Host, Peripheral and OTG. So HCD is added only before
>>> entering into Host mode. Root hub initialization is done in
>>> different steps to decrease boot up time. But this makes B-device
>>> difficult to meet HNP timings. Hence eliminate delays involved in
>>> root hub initialization for B-host.

>>> This patch also marks hnp_supported flag TRUE for B-host while
>>> registering the bus.

>>> Change-Id: I821775e8c90bd71a7abbe17176f189664a1841e1
>>> Signed-off-by: Pavankumar Kondeti<pkondeti@codeaurora.org>
>> [...]

>>> index ac79fd5..2df61ba 100644
>>> --- a/drivers/usb/core/hub.c
>>> +++ b/drivers/usb/core/hub.c
>>> @@ -680,6 +680,7 @@ static void hub_activate(struct usb_hub *hub, enum
>>> hub_activation_type type)
>>> int status;
>>> bool need_debounce_delay = false;
>>> unsigned delay;
>>> + bool hnp_in_progress = hdev->bus->is_b_host&& (type == HUB_INIT);

>> Parens here are not necessary.

> there's also a missing space before &&

    That's my Thunderbird eating spaces before &. :-)

WBR, Sergei

Re: [RFC v2 1/4] USB: core: OTG Supplement Revision 2.0 updates

[Alan Stern]

On Thu, 16 Dec 2010, Pavankumar Kondeti wrote:

> 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 within 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.

This combination of things doesn't make sense:

> index b9278a1..baada06 100644
> --- a/drivers/usb/core/driver.c
> +++ b/drivers/usb/core/driver.c
> @@ -1270,6 +1282,47 @@ 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)
> +{

...

> +}
> +#endif

usb_hnp_polling_work() is defined only when CONFIG_USB_OTG is set.

> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index e70aeaf..5dd59e9 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -869,6 +869,7 @@ static void usb_bus_init (struct usb_bus *bus)
>  	bus->bandwidth_isoc_reqs = 0;
>  
>  	INIT_LIST_HEAD (&bus->bus_list);
> +	INIT_DELAYED_WORK(&bus->hnp_polling, usb_hnp_polling_work);
>  }

But its address is taken regardless of CONFIG_USB_OTG.

> diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
> index b975450..ffa16e1 100644
> --- a/drivers/usb/core/usb.h
> +++ b/drivers/usb/core/usb.h
> @@ -72,6 +72,14 @@ 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);
> +#else
> +static inline void usb_hnp_polling_work(struct work_struct *work)
> +{
> +}
> +#endif

Otherwise it is an empty inline routine.

But taking the address of an inline routine forces the compiler to
produce an out-of-line version.  Therefore you might as well explicitly
define usb_hnp_polling_work() as an empty function when CONFIG_USB_OTG
isn't set.

Alan Stern

Re: [RFC v2 1/4] USB: core: OTG Supplement Revision 2.0 updates

[Pavan Kondeti]

On 12/16/2010 9:04 PM, Alan Stern wrote:
> On Thu, 16 Dec 2010, Pavankumar Kondeti wrote:
> 
>> 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 within 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.
> 
> This combination of things doesn't make sense:
> 
>> index b9278a1..baada06 100644
>> --- a/drivers/usb/core/driver.c
>> +++ b/drivers/usb/core/driver.c
>> @@ -1270,6 +1282,47 @@ 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)
>> +{
> 
> ...
> 
>> +}
>> +#endif
> 
> usb_hnp_polling_work() is defined only when CONFIG_USB_OTG is set.
> 
>> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
>> index e70aeaf..5dd59e9 100644
>> --- a/drivers/usb/core/hcd.c
>> +++ b/drivers/usb/core/hcd.c
>> @@ -869,6 +869,7 @@ static void usb_bus_init (struct usb_bus *bus)
>>  	bus->bandwidth_isoc_reqs = 0;
>>  
>>  	INIT_LIST_HEAD (&bus->bus_list);
>> +	INIT_DELAYED_WORK(&bus->hnp_polling, usb_hnp_polling_work);
>>  }
> 
> But its address is taken regardless of CONFIG_USB_OTG.
> 
>> diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
>> index b975450..ffa16e1 100644
>> --- a/drivers/usb/core/usb.h
>> +++ b/drivers/usb/core/usb.h
>> @@ -72,6 +72,14 @@ 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);
>> +#else
>> +static inline void usb_hnp_polling_work(struct work_struct *work)
>> +{
>> +}
>> +#endif
> 
> Otherwise it is an empty inline routine.
> 
> But taking the address of an inline routine forces the compiler to
> produce an out-of-line version.  Therefore you might as well explicitly
> define usb_hnp_polling_work() as an empty function when CONFIG_USB_OTG
> isn't set.
> 
Thanks. I got it. Will fix it next version.

-- 
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.