[PATCH] USB: usb gadget zero, basic OTG updates

This patch teaches "gadget zero" enough about OTG to pass simple USBCV
tests, mostly by including OTG descriptors in each configuration.  It
tests and reports OTG status, as reported by the USB controller driver.

It also adds an option to build gadget zero to act as the designated
OTG "HNP Test Device", which exists primarily to trigger HNP.  However,
it won't currently request HNP.

Includes other minor tweaks:  delete a timer on disconnect, reset
the req->zero flag, don't autoresume after disconnect.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/gadget/Kconfig

@@ -208,6 +208,16 @@ config USB_ZERO
 	  Say "y" to link the driver statically, or "m" to build a
 	  dynamically linked module called "g_zero".
 
+config USB_ZERO_HNPTEST
+	boolean "HNP Test Device"
+	depends on USB_ZERO && USB_OTG
+	help
+	  You can configure this device to enumerate using the device
+	  identifiers of the USB-OTG test device.  That means that when
+	  this gadget connects to another OTG device, with this one using
+	  the "B-Peripheral" role, that device will use HNP to let this
+	  one serve as the USB host instead (in the "B-Host" role).
+
 config USB_ETH
 	tristate "Ethernet Gadget"
 	depends on NET

drivers/usb/gadget/zero.c

@@ -194,8 +194,13 @@ module_param (loopdefault, bool, S_IRUGO|S_IWUSR);
  * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  * Instead:  allocate your own, using normal USB-IF procedures.
  */
+#ifndef	CONFIG_USB_ZERO_HNPTEST
 #define DRIVER_VENDOR_NUM	0x0525		/* NetChip */
 #define DRIVER_PRODUCT_NUM	0xa4a0		/* Linux-USB "Gadget Zero" */
+#else
+#define DRIVER_VENDOR_NUM	0x1a0a		/* OTG test device IDs */
+#define DRIVER_PRODUCT_NUM	0xbadd
+#endif
 
 /*-------------------------------------------------------------------------*/
 
@@ -259,6 +264,14 @@ loopback_config = {
 	.bMaxPower =		1,	/* self-powered */
 };
 
+static struct usb_otg_descriptor
+otg_descriptor = {
+	.bLength =		sizeof otg_descriptor,
+	.bDescriptorType =	USB_DT_OTG,
+
+	.bmAttributes =		USB_OTG_SRP,
+};
+
 /* one interface in each configuration */
 
 static const struct usb_interface_descriptor
@@ -302,6 +315,7 @@ fs_sink_desc = {
 };
 
 static const struct usb_descriptor_header *fs_source_sink_function [] = {
+	(struct usb_descriptor_header *) &otg_descriptor,
 	(struct usb_descriptor_header *) &source_sink_intf,
 	(struct usb_descriptor_header *) &fs_sink_desc,
 	(struct usb_descriptor_header *) &fs_source_desc,
@@ -309,6 +323,7 @@ static const struct usb_descriptor_header *fs_source_sink_function [] = {
 };
 
 static const struct usb_descriptor_header *fs_loopback_function [] = {
+	(struct usb_descriptor_header *) &otg_descriptor,
 	(struct usb_descriptor_header *) &loopback_intf,
 	(struct usb_descriptor_header *) &fs_sink_desc,
 	(struct usb_descriptor_header *) &fs_source_desc,
@@ -356,6 +371,7 @@ dev_qualifier = {
 };
 
 static const struct usb_descriptor_header *hs_source_sink_function [] = {
+	(struct usb_descriptor_header *) &otg_descriptor,
 	(struct usb_descriptor_header *) &source_sink_intf,
 	(struct usb_descriptor_header *) &hs_source_desc,
 	(struct usb_descriptor_header *) &hs_sink_desc,
@@ -363,6 +379,7 @@ static const struct usb_descriptor_header *hs_source_sink_function [] = {
 };
 
 static const struct usb_descriptor_header *hs_loopback_function [] = {
+	(struct usb_descriptor_header *) &otg_descriptor,
 	(struct usb_descriptor_header *) &loopback_intf,
 	(struct usb_descriptor_header *) &hs_source_desc,
 	(struct usb_descriptor_header *) &hs_sink_desc,
@@ -444,6 +461,10 @@ config_buf (struct usb_gadget *gadget,
 			? fs_source_sink_function
 			: fs_loopback_function;
 
+	/* for now, don't advertise srp-only devices */
+	if (!gadget->is_otg)
+		function++;
+
 	len = usb_gadget_config_buf (is_source_sink
 					? &source_sink_config
 					: &loopback_config,
@@ -485,7 +506,7 @@ static void free_ep_req (struct usb_ep *ep, struct usb_request *req)
 
 /* optionally require specific source/sink data patterns  */
 
-static inline int
+static int
 check_read_data (
 	struct zero_dev		*dev,
 	struct usb_ep		*ep,
@@ -519,7 +540,7 @@ check_read_data (
 	return 0;
 }
 
-static inline void
+static void
 reinit_write_data (
 	struct zero_dev		*dev,
 	struct usb_ep		*ep,
@@ -811,6 +832,7 @@ static void zero_reset_config (struct zero_dev *dev)
 		dev->out_ep = 0;
 	}
 	dev->config = 0;
+	del_timer (&dev->resume);
 }
 
 /* change our operational config.  this code must agree with the code
@@ -902,6 +924,7 @@ zero_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 	/* usually this stores reply data in the pre-allocated ep0 buffer,
 	 * but config change events will reconfigure hardware.
 	 */
+	req->zero = 0;
 	switch (ctrl->bRequest) {
 
 	case USB_REQ_GET_DESCRIPTOR:
@@ -951,6 +974,12 @@ zero_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 	case USB_REQ_SET_CONFIGURATION:
 		if (ctrl->bRequestType != 0)
 			goto unknown;
+		if (gadget->a_hnp_support)
+			DBG (dev, "HNP available\n");
+		else if (gadget->a_alt_hnp_support)
+			DBG (dev, "HNP needs a different root port\n");
+		else
+			VDBG (dev, "HNP inactive\n");
 		spin_lock (&dev->lock);
 		value = zero_set_config (dev, ctrl->wValue, GFP_ATOMIC);
 		spin_unlock (&dev->lock);
@@ -1080,8 +1109,10 @@ zero_autoresume (unsigned long _dev)
 	/* normally the host would be woken up for something
 	 * more significant than just a timer firing...
 	 */
+	if (dev->gadget->speed != USB_SPEED_UNKNOWN) {
 		status = usb_gadget_wakeup (dev->gadget);
 		DBG (dev, "wakeup --> %d\n", status);
+	}
 }
 
 /*-------------------------------------------------------------------------*/
@@ -1199,6 +1230,12 @@ zero_bind (struct usb_gadget *gadget)
 	hs_sink_desc.bEndpointAddress = fs_sink_desc.bEndpointAddress;
 #endif
 
+	if (gadget->is_otg) {
+		otg_descriptor.bmAttributes |= USB_OTG_HNP,
+		source_sink_config.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+		loopback_config.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+	}
+
 	usb_gadget_set_selfpowered (gadget);
 
 	init_timer (&dev->resume);