Merge tag 'usb-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB changes from Greg Kroah-Hartman:
 "Here is the big USB pull request for 3.7-rc1

  There are lots of gadget driver changes (including copying a bunch of
  files into the drivers/staging/ccg/ directory so that the other gadget
  drivers can be fixed up properly without breaking that driver), and we
  remove the old obsolete ub.c driver from the tree.

  There are also the usual XHCI set of updates, and other various driver
  changes and updates.  We also are trying hard to remove the old dbg()
  macro, but the final bits of that removal will be coming in through
  the networking tree before we can delete it for good.

  All of these patches have been in the linux-next tree.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

Fix up several annoying - but fairly mindless - conflicts due to the
termios structure having moved into the tty device, and often clashing
with dbg -> dev_dbg conversion.

* tag 'usb-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (339 commits)
  USB: ezusb: move ezusb.c from drivers/usb/serial to drivers/usb/misc
  USB: uas: fix gcc warning
  USB: uas: fix locking
  USB: Fix race condition when removing host controllers
  USB: uas: add locking
  USB: uas: fix abort
  USB: uas: remove aborted field, replace with status bit.
  USB: uas: fix task management
  USB: uas: keep track of command urbs
  xhci: Intel Panther Point BEI quirk.
  powerpc/usb: remove checking PHY_CLK_VALID for UTMI PHY
  USB: ftdi_sio: add TIAO USB Multi-Protocol Adapter (TUMPA) support
  Revert "usb : Add sysfs files to control port power."
  USB: serial: remove vizzini driver
  usb: host: xhci: Fix Null pointer dereferencing with 71c731a for non-x86 systems
  Increase XHCI suspend timeout to 16ms
  USB: ohci-at91: fix null pointer in ohci_hcd_at91_overcurrent_irq
  USB: sierra_ms: don't keep unused variable
  fsl/usb: Add support for USB controller version 2.4
  USB: qcaux: add Pantech vendor class match
  ...

1 files changed, 814 insertions, 0 deletions

diff --git a/drivers/staging/ccg/f_acm.c b/drivers/staging/ccg/f_acm.c
new file mode 100644
index 000000000000..d672250a61fa
--- /dev/null
+++ b/drivers/staging/ccg/f_acm.c
@@ -0,0 +1,814 @@
+/*
+ * f_acm.c -- USB CDC serial (ACM) function driver
+ *
+ * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
+ * Copyright (C) 2008 by David Brownell
+ * Copyright (C) 2008 by Nokia Corporation
+ * Copyright (C) 2009 by Samsung Electronics
+ * Author: Michal Nazarewicz (mina86@mina86.com)
+ *
+ * This software is distributed under the terms of the GNU General
+ * Public License ("GPL") as published by the Free Software Foundation,
+ * either version 2 of that License or (at your option) any later version.
+ */
+
+/* #define VERBOSE_DEBUG */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+
+#include "u_serial.h"
+#include "gadget_chips.h"
+
+
+/*
+ * This CDC ACM function support just wraps control functions and
+ * notifications around the generic serial-over-usb code.
+ *
+ * Because CDC ACM is standardized by the USB-IF, many host operating
+ * systems have drivers for it.  Accordingly, ACM is the preferred
+ * interop solution for serial-port type connections.  The control
+ * models are often not necessary, and in any case don't do much in
+ * this bare-bones implementation.
+ *
+ * Note that even MS-Windows has some support for ACM.  However, that
+ * support is somewhat broken because when you use ACM in a composite
+ * device, having multiple interfaces confuses the poor OS.  It doesn't
+ * seem to understand CDC Union descriptors.  The new "association"
+ * descriptors (roughly equivalent to CDC Unions) may sometimes help.
+ */
+
+struct f_acm {
+	struct gserial			port;
+	u8				ctrl_id, data_id;
+	u8				port_num;
+
+	u8				pending;
+
+	/* lock is mostly for pending and notify_req ... they get accessed
+	 * by callbacks both from tty (open/close/break) under its spinlock,
+	 * and notify_req.complete() which can't use that lock.
+	 */
+	spinlock_t			lock;
+
+	struct usb_ep			*notify;
+	struct usb_request		*notify_req;
+
+	struct usb_cdc_line_coding	port_line_coding;	/* 8-N-1 etc */
+
+	/* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
+	u16				port_handshake_bits;
+#define ACM_CTRL_RTS	(1 << 1)	/* unused with full duplex */
+#define ACM_CTRL_DTR	(1 << 0)	/* host is ready for data r/w */
+
+	/* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
+	u16				serial_state;
+#define ACM_CTRL_OVERRUN	(1 << 6)
+#define ACM_CTRL_PARITY		(1 << 5)
+#define ACM_CTRL_FRAMING	(1 << 4)
+#define ACM_CTRL_RI		(1 << 3)
+#define ACM_CTRL_BRK		(1 << 2)
+#define ACM_CTRL_DSR		(1 << 1)
+#define ACM_CTRL_DCD		(1 << 0)
+};
+
+static inline struct f_acm *func_to_acm(struct usb_function *f)
+{
+	return container_of(f, struct f_acm, port.func);
+}
+
+static inline struct f_acm *port_to_acm(struct gserial *p)
+{
+	return container_of(p, struct f_acm, port);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* notification endpoint uses smallish and infrequent fixed-size messages */
+
+#define GS_LOG2_NOTIFY_INTERVAL		5	/* 1 << 5 == 32 msec */
+#define GS_NOTIFY_MAXPACKET		10	/* notification + 2 bytes */
+
+/* interface and class descriptors: */
+
+static struct usb_interface_assoc_descriptor
+acm_iad_descriptor = {
+	.bLength =		sizeof acm_iad_descriptor,
+	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
+
+	/* .bFirstInterface =	DYNAMIC, */
+	.bInterfaceCount = 	2,	// control + data
+	.bFunctionClass =	USB_CLASS_COMM,
+	.bFunctionSubClass =	USB_CDC_SUBCLASS_ACM,
+	.bFunctionProtocol =	USB_CDC_ACM_PROTO_AT_V25TER,
+	/* .iFunction =		DYNAMIC */
+};
+
+
+static struct usb_interface_descriptor acm_control_interface_desc = {
+	.bLength =		USB_DT_INTERFACE_SIZE,
+	.bDescriptorType =	USB_DT_INTERFACE,
+	/* .bInterfaceNumber = DYNAMIC */
+	.bNumEndpoints =	1,
+	.bInterfaceClass =	USB_CLASS_COMM,
+	.bInterfaceSubClass =	USB_CDC_SUBCLASS_ACM,
+	.bInterfaceProtocol =	USB_CDC_ACM_PROTO_AT_V25TER,
+	/* .iInterface = DYNAMIC */
+};
+
+static struct usb_interface_descriptor acm_data_interface_desc = {
+	.bLength =		USB_DT_INTERFACE_SIZE,
+	.bDescriptorType =	USB_DT_INTERFACE,
+	/* .bInterfaceNumber = DYNAMIC */
+	.bNumEndpoints =	2,
+	.bInterfaceClass =	USB_CLASS_CDC_DATA,
+	.bInterfaceSubClass =	0,
+	.bInterfaceProtocol =	0,
+	/* .iInterface = DYNAMIC */
+};
+
+static struct usb_cdc_header_desc acm_header_desc = {
+	.bLength =		sizeof(acm_header_desc),
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
+	.bcdCDC =		cpu_to_le16(0x0110),
+};
+
+static struct usb_cdc_call_mgmt_descriptor
+acm_call_mgmt_descriptor = {
+	.bLength =		sizeof(acm_call_mgmt_descriptor),
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_CALL_MANAGEMENT_TYPE,
+	.bmCapabilities =	0,
+	/* .bDataInterface = DYNAMIC */
+};
+
+static struct usb_cdc_acm_descriptor acm_descriptor = {
+	.bLength =		sizeof(acm_descriptor),
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_ACM_TYPE,
+	.bmCapabilities =	USB_CDC_CAP_LINE,
+};
+
+static struct usb_cdc_union_desc acm_union_desc = {
+	.bLength =		sizeof(acm_union_desc),
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
+	/* .bMasterInterface0 =	DYNAMIC */
+	/* .bSlaveInterface0 =	DYNAMIC */
+};
+
+/* full speed support: */
+
+static struct usb_endpoint_descriptor acm_fs_notify_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_INT,
+	.wMaxPacketSize =	cpu_to_le16(GS_NOTIFY_MAXPACKET),
+	.bInterval =		1 << GS_LOG2_NOTIFY_INTERVAL,
+};
+
+static struct usb_endpoint_descriptor acm_fs_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor acm_fs_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *acm_fs_function[] = {
+	(struct usb_descriptor_header *) &acm_iad_descriptor,
+	(struct usb_descriptor_header *) &acm_control_interface_desc,
+	(struct usb_descriptor_header *) &acm_header_desc,
+	(struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
+	(struct usb_descriptor_header *) &acm_descriptor,
+	(struct usb_descriptor_header *) &acm_union_desc,
+	(struct usb_descriptor_header *) &acm_fs_notify_desc,
+	(struct usb_descriptor_header *) &acm_data_interface_desc,
+	(struct usb_descriptor_header *) &acm_fs_in_desc,
+	(struct usb_descriptor_header *) &acm_fs_out_desc,
+	NULL,
+};
+
+/* high speed support: */
+
+static struct usb_endpoint_descriptor acm_hs_notify_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_INT,
+	.wMaxPacketSize =	cpu_to_le16(GS_NOTIFY_MAXPACKET),
+	.bInterval =		GS_LOG2_NOTIFY_INTERVAL+4,
+};
+
+static struct usb_endpoint_descriptor acm_hs_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor acm_hs_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *acm_hs_function[] = {
+	(struct usb_descriptor_header *) &acm_iad_descriptor,
+	(struct usb_descriptor_header *) &acm_control_interface_desc,
+	(struct usb_descriptor_header *) &acm_header_desc,
+	(struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
+	(struct usb_descriptor_header *) &acm_descriptor,
+	(struct usb_descriptor_header *) &acm_union_desc,
+	(struct usb_descriptor_header *) &acm_hs_notify_desc,
+	(struct usb_descriptor_header *) &acm_data_interface_desc,
+	(struct usb_descriptor_header *) &acm_hs_in_desc,
+	(struct usb_descriptor_header *) &acm_hs_out_desc,
+	NULL,
+};
+
+static struct usb_endpoint_descriptor acm_ss_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_endpoint_descriptor acm_ss_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
+	.bLength =              sizeof acm_ss_bulk_comp_desc,
+	.bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
+};
+
+static struct usb_descriptor_header *acm_ss_function[] = {
+	(struct usb_descriptor_header *) &acm_iad_descriptor,
+	(struct usb_descriptor_header *) &acm_control_interface_desc,
+	(struct usb_descriptor_header *) &acm_header_desc,
+	(struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
+	(struct usb_descriptor_header *) &acm_descriptor,
+	(struct usb_descriptor_header *) &acm_union_desc,
+	(struct usb_descriptor_header *) &acm_hs_notify_desc,
+	(struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
+	(struct usb_descriptor_header *) &acm_data_interface_desc,
+	(struct usb_descriptor_header *) &acm_ss_in_desc,
+	(struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
+	(struct usb_descriptor_header *) &acm_ss_out_desc,
+	(struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
+	NULL,
+};
+
+/* string descriptors: */
+
+#define ACM_CTRL_IDX	0
+#define ACM_DATA_IDX	1
+#define ACM_IAD_IDX	2
+
+/* static strings, in UTF-8 */
+static struct usb_string acm_string_defs[] = {
+	[ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
+	[ACM_DATA_IDX].s = "CDC ACM Data",
+	[ACM_IAD_IDX ].s = "CDC Serial",
+	{  /* ZEROES END LIST */ },
+};
+
+static struct usb_gadget_strings acm_string_table = {
+	.language =		0x0409,	/* en-us */
+	.strings =		acm_string_defs,
+};
+
+static struct usb_gadget_strings *acm_strings[] = {
+	&acm_string_table,
+	NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+/* ACM control ... data handling is delegated to tty library code.
+ * The main task of this function is to activate and deactivate
+ * that code based on device state; track parameters like line
+ * speed, handshake state, and so on; and issue notifications.
+ */
+
+static void acm_complete_set_line_coding(struct usb_ep *ep,
+		struct usb_request *req)
+{
+	struct f_acm	*acm = ep->driver_data;
+	struct usb_composite_dev *cdev = acm->port.func.config->cdev;
+
+	if (req->status != 0) {
+		DBG(cdev, "acm ttyGS%d completion, err %d\n",
+				acm->port_num, req->status);
+		return;
+	}
+
+	/* normal completion */
+	if (req->actual != sizeof(acm->port_line_coding)) {
+		DBG(cdev, "acm ttyGS%d short resp, len %d\n",
+				acm->port_num, req->actual);
+		usb_ep_set_halt(ep);
+	} else {
+		struct usb_cdc_line_coding	*value = req->buf;
+
+		/* REVISIT:  we currently just remember this data.
+		 * If we change that, (a) validate it first, then
+		 * (b) update whatever hardware needs updating,
+		 * (c) worry about locking.  This is information on
+		 * the order of 9600-8-N-1 ... most of which means
+		 * nothing unless we control a real RS232 line.
+		 */
+		acm->port_line_coding = *value;
+	}
+}
+
+static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
+{
+	struct f_acm		*acm = func_to_acm(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+	struct usb_request	*req = cdev->req;
+	int			value = -EOPNOTSUPP;
+	u16			w_index = le16_to_cpu(ctrl->wIndex);
+	u16			w_value = le16_to_cpu(ctrl->wValue);
+	u16			w_length = le16_to_cpu(ctrl->wLength);
+
+	/* composite driver infrastructure handles everything except
+	 * CDC class messages; interface activation uses set_alt().
+	 *
+	 * Note CDC spec table 4 lists the ACM request profile.  It requires
+	 * encapsulated command support ... we don't handle any, and respond
+	 * to them by stalling.  Options include get/set/clear comm features
+	 * (not that useful) and SEND_BREAK.
+	 */
+	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
+
+	/* SET_LINE_CODING ... just read and save what the host sends */
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+			| USB_CDC_REQ_SET_LINE_CODING:
+		if (w_length != sizeof(struct usb_cdc_line_coding)
+				|| w_index != acm->ctrl_id)
+			goto invalid;
+
+		value = w_length;
+		cdev->gadget->ep0->driver_data = acm;
+		req->complete = acm_complete_set_line_coding;
+		break;
+
+	/* GET_LINE_CODING ... return what host sent, or initial value */
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+			| USB_CDC_REQ_GET_LINE_CODING:
+		if (w_index != acm->ctrl_id)
+			goto invalid;
+
+		value = min_t(unsigned, w_length,
+				sizeof(struct usb_cdc_line_coding));
+		memcpy(req->buf, &acm->port_line_coding, value);
+		break;
+
+	/* SET_CONTROL_LINE_STATE ... save what the host sent */
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+			| USB_CDC_REQ_SET_CONTROL_LINE_STATE:
+		if (w_index != acm->ctrl_id)
+			goto invalid;
+
+		value = 0;
+
+		/* FIXME we should not allow data to flow until the
+		 * host sets the ACM_CTRL_DTR bit; and when it clears
+		 * that bit, we should return to that no-flow state.
+		 */
+		acm->port_handshake_bits = w_value;
+		break;
+
+	default:
+invalid:
+		VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
+			ctrl->bRequestType, ctrl->bRequest,
+			w_value, w_index, w_length);
+	}
+
+	/* respond with data transfer or status phase? */
+	if (value >= 0) {
+		DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
+			acm->port_num, ctrl->bRequestType, ctrl->bRequest,
+			w_value, w_index, w_length);
+		req->zero = 0;
+		req->length = value;
+		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+		if (value < 0)
+			ERROR(cdev, "acm response on ttyGS%d, err %d\n",
+					acm->port_num, value);
+	}
+
+	/* device either stalls (value < 0) or reports success */
+	return value;
+}
+
+static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+	struct f_acm		*acm = func_to_acm(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	/* we know alt == 0, so this is an activation or a reset */
+
+	if (intf == acm->ctrl_id) {
+		if (acm->notify->driver_data) {
+			VDBG(cdev, "reset acm control interface %d\n", intf);
+			usb_ep_disable(acm->notify);
+		} else {
+			VDBG(cdev, "init acm ctrl interface %d\n", intf);
+			if (config_ep_by_speed(cdev->gadget, f, acm->notify))
+				return -EINVAL;
+		}
+		usb_ep_enable(acm->notify);
+		acm->notify->driver_data = acm;
+
+	} else if (intf == acm->data_id) {
+		if (acm->port.in->driver_data) {
+			DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
+			gserial_disconnect(&acm->port);
+		}
+		if (!acm->port.in->desc || !acm->port.out->desc) {
+			DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
+			if (config_ep_by_speed(cdev->gadget, f,
+					       acm->port.in) ||
+			    config_ep_by_speed(cdev->gadget, f,
+					       acm->port.out)) {
+				acm->port.in->desc = NULL;
+				acm->port.out->desc = NULL;
+				return -EINVAL;
+			}
+		}
+		gserial_connect(&acm->port, acm->port_num);
+
+	} else
+		return -EINVAL;
+
+	return 0;
+}
+
+static void acm_disable(struct usb_function *f)
+{
+	struct f_acm	*acm = func_to_acm(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
+	gserial_disconnect(&acm->port);
+	usb_ep_disable(acm->notify);
+	acm->notify->driver_data = NULL;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/**
+ * acm_cdc_notify - issue CDC notification to host
+ * @acm: wraps host to be notified
+ * @type: notification type
+ * @value: Refer to cdc specs, wValue field.
+ * @data: data to be sent
+ * @length: size of data
+ * Context: irqs blocked, acm->lock held, acm_notify_req non-null
+ *
+ * Returns zero on success or a negative errno.
+ *
+ * See section 6.3.5 of the CDC 1.1 specification for information
+ * about the only notification we issue:  SerialState change.
+ */
+static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
+		void *data, unsigned length)
+{
+	struct usb_ep			*ep = acm->notify;
+	struct usb_request		*req;
+	struct usb_cdc_notification	*notify;
+	const unsigned			len = sizeof(*notify) + length;
+	void				*buf;
+	int				status;
+
+	req = acm->notify_req;
+	acm->notify_req = NULL;
+	acm->pending = false;
+
+	req->length = len;
+	notify = req->buf;
+	buf = notify + 1;
+
+	notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
+			| USB_RECIP_INTERFACE;
+	notify->bNotificationType = type;
+	notify->wValue = cpu_to_le16(value);
+	notify->wIndex = cpu_to_le16(acm->ctrl_id);
+	notify->wLength = cpu_to_le16(length);
+	memcpy(buf, data, length);
+
+	/* ep_queue() can complete immediately if it fills the fifo... */
+	spin_unlock(&acm->lock);
+	status = usb_ep_queue(ep, req, GFP_ATOMIC);
+	spin_lock(&acm->lock);
+
+	if (status < 0) {
+		ERROR(acm->port.func.config->cdev,
+				"acm ttyGS%d can't notify serial state, %d\n",
+				acm->port_num, status);
+		acm->notify_req = req;
+	}
+
+	return status;
+}
+
+static int acm_notify_serial_state(struct f_acm *acm)
+{
+	struct usb_composite_dev *cdev = acm->port.func.config->cdev;
+	int			status;
+
+	spin_lock(&acm->lock);
+	if (acm->notify_req) {
+		DBG(cdev, "acm ttyGS%d serial state %04x\n",
+				acm->port_num, acm->serial_state);
+		status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
+				0, &acm->serial_state, sizeof(acm->serial_state));
+	} else {
+		acm->pending = true;
+		status = 0;
+	}
+	spin_unlock(&acm->lock);
+	return status;
+}
+
+static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_acm		*acm = req->context;
+	u8			doit = false;
+
+	/* on this call path we do NOT hold the port spinlock,
+	 * which is why ACM needs its own spinlock
+	 */
+	spin_lock(&acm->lock);
+	if (req->status != -ESHUTDOWN)
+		doit = acm->pending;
+	acm->notify_req = req;
+	spin_unlock(&acm->lock);
+
+	if (doit)
+		acm_notify_serial_state(acm);
+}
+
+/* connect == the TTY link is open */
+
+static void acm_connect(struct gserial *port)
+{
+	struct f_acm		*acm = port_to_acm(port);
+
+	acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
+	acm_notify_serial_state(acm);
+}
+
+static void acm_disconnect(struct gserial *port)
+{
+	struct f_acm		*acm = port_to_acm(port);
+
+	acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
+	acm_notify_serial_state(acm);
+}
+
+static int acm_send_break(struct gserial *port, int duration)
+{
+	struct f_acm		*acm = port_to_acm(port);
+	u16			state;
+
+	state = acm->serial_state;
+	state &= ~ACM_CTRL_BRK;
+	if (duration)
+		state |= ACM_CTRL_BRK;
+
+	acm->serial_state = state;
+	return acm_notify_serial_state(acm);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* ACM function driver setup/binding */
+static int
+acm_bind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct usb_composite_dev *cdev = c->cdev;
+	struct f_acm		*acm = func_to_acm(f);
+	int			status;
+	struct usb_ep		*ep;
+
+	/* allocate instance-specific interface IDs, and patch descriptors */
+	status = usb_interface_id(c, f);
+	if (status < 0)
+		goto fail;
+	acm->ctrl_id = status;
+	acm_iad_descriptor.bFirstInterface = status;
+
+	acm_control_interface_desc.bInterfaceNumber = status;
+	acm_union_desc .bMasterInterface0 = status;
+
+	status = usb_interface_id(c, f);
+	if (status < 0)
+		goto fail;
+	acm->data_id = status;
+
+	acm_data_interface_desc.bInterfaceNumber = status;
+	acm_union_desc.bSlaveInterface0 = status;
+	acm_call_mgmt_descriptor.bDataInterface = status;
+
+	status = -ENODEV;
+
+	/* allocate instance-specific endpoints */
+	ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
+	if (!ep)
+		goto fail;
+	acm->port.in = ep;
+	ep->driver_data = cdev;	/* claim */
+
+	ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
+	if (!ep)
+		goto fail;
+	acm->port.out = ep;
+	ep->driver_data = cdev;	/* claim */
+
+	ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
+	if (!ep)
+		goto fail;
+	acm->notify = ep;
+	ep->driver_data = cdev;	/* claim */
+
+	/* allocate notification */
+	acm->notify_req = gs_alloc_req(ep,
+			sizeof(struct usb_cdc_notification) + 2,
+			GFP_KERNEL);
+	if (!acm->notify_req)
+		goto fail;
+
+	acm->notify_req->complete = acm_cdc_notify_complete;
+	acm->notify_req->context = acm;
+
+	/* copy descriptors */
+	f->descriptors = usb_copy_descriptors(acm_fs_function);
+	if (!f->descriptors)
+		goto fail;
+
+	/* support all relevant hardware speeds... we expect that when
+	 * hardware is dual speed, all bulk-capable endpoints work at
+	 * both speeds
+	 */
+	if (gadget_is_dualspeed(c->cdev->gadget)) {
+		acm_hs_in_desc.bEndpointAddress =
+				acm_fs_in_desc.bEndpointAddress;
+		acm_hs_out_desc.bEndpointAddress =
+				acm_fs_out_desc.bEndpointAddress;
+		acm_hs_notify_desc.bEndpointAddress =
+				acm_fs_notify_desc.bEndpointAddress;
+
+		/* copy descriptors */
+		f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
+	}
+	if (gadget_is_superspeed(c->cdev->gadget)) {
+		acm_ss_in_desc.bEndpointAddress =
+			acm_fs_in_desc.bEndpointAddress;
+		acm_ss_out_desc.bEndpointAddress =
+			acm_fs_out_desc.bEndpointAddress;
+
+		/* copy descriptors, and track endpoint copies */
+		f->ss_descriptors = usb_copy_descriptors(acm_ss_function);
+		if (!f->ss_descriptors)
+			goto fail;
+	}
+
+	DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
+			acm->port_num,
+			gadget_is_superspeed(c->cdev->gadget) ? "super" :
+			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+			acm->port.in->name, acm->port.out->name,
+			acm->notify->name);
+	return 0;
+
+fail:
+	if (acm->notify_req)
+		gs_free_req(acm->notify, acm->notify_req);
+
+	/* we might as well release our claims on endpoints */
+	if (acm->notify)
+		acm->notify->driver_data = NULL;
+	if (acm->port.out)
+		acm->port.out->driver_data = NULL;
+	if (acm->port.in)
+		acm->port.in->driver_data = NULL;
+
+	ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
+
+	return status;
+}
+
+static void
+acm_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct f_acm		*acm = func_to_acm(f);
+
+	if (gadget_is_dualspeed(c->cdev->gadget))
+		usb_free_descriptors(f->hs_descriptors);
+	if (gadget_is_superspeed(c->cdev->gadget))
+		usb_free_descriptors(f->ss_descriptors);
+	usb_free_descriptors(f->descriptors);
+	gs_free_req(acm->notify, acm->notify_req);
+	kfree(acm);
+}
+
+/* Some controllers can't support CDC ACM ... */
+static inline bool can_support_cdc(struct usb_configuration *c)
+{
+	/* everything else is *probably* fine ... */
+	return true;
+}
+
+/**
+ * acm_bind_config - add a CDC ACM function to a configuration
+ * @c: the configuration to support the CDC ACM instance
+ * @port_num: /dev/ttyGS* port this interface will use
+ * Context: single threaded during gadget setup
+ *
+ * Returns zero on success, else negative errno.
+ *
+ * Caller must have called @gserial_setup() with enough ports to
+ * handle all the ones it binds.  Caller is also responsible
+ * for calling @gserial_cleanup() before module unload.
+ */
+int acm_bind_config(struct usb_configuration *c, u8 port_num)
+{
+	struct f_acm	*acm;
+	int		status;
+
+	if (!can_support_cdc(c))
+		return -EINVAL;
+
+	/* REVISIT might want instance-specific strings to help
+	 * distinguish instances ...
+	 */
+
+	/* maybe allocate device-global string IDs, and patch descriptors */
+	if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
+		status = usb_string_id(c->cdev);
+		if (status < 0)
+			return status;
+		acm_string_defs[ACM_CTRL_IDX].id = status;
+
+		acm_control_interface_desc.iInterface = status;
+
+		status = usb_string_id(c->cdev);
+		if (status < 0)
+			return status;
+		acm_string_defs[ACM_DATA_IDX].id = status;
+
+		acm_data_interface_desc.iInterface = status;
+
+		status = usb_string_id(c->cdev);
+		if (status < 0)
+			return status;
+		acm_string_defs[ACM_IAD_IDX].id = status;
+
+		acm_iad_descriptor.iFunction = status;
+	}
+
+	/* allocate and initialize one new instance */
+	acm = kzalloc(sizeof *acm, GFP_KERNEL);
+	if (!acm)
+		return -ENOMEM;
+
+	spin_lock_init(&acm->lock);
+
+	acm->port_num = port_num;
+
+	acm->port.connect = acm_connect;
+	acm->port.disconnect = acm_disconnect;
+	acm->port.send_break = acm_send_break;
+
+	acm->port.func.name = "acm";
+	acm->port.func.strings = acm_strings;
+	/* descriptors are per-instance copies */
+	acm->port.func.bind = acm_bind;
+	acm->port.func.unbind = acm_unbind;
+	acm->port.func.set_alt = acm_set_alt;
+	acm->port.func.setup = acm_setup;
+	acm->port.func.disable = acm_disable;
+
+	status = usb_add_function(c, &acm->port.func);
+	if (status)
+		kfree(acm);
+	return status;
+}