+/**
+ * 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 sucess 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);
+}
+
+/*-------------------------------------------------------------------------*/
+