+
+/*
+ * ***************************************************************************
+ * Sysfs Attribute
+ * ***************************************************************************
+ */
+
+ssize_t show_latency_timer(struct device *dev, char *buf)
+{
+ struct usb_serial_port *port = to_usb_serial_port(dev);
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+ struct usb_device *udev;
+ unsigned short latency = 0;
+ int rv = 0;
+
+ udev = to_usb_device(dev);
+
+ dbg("%s",__FUNCTION__);
+
+ rv = usb_control_msg(udev,
+ usb_rcvctrlpipe(udev, 0),
+ FTDI_SIO_GET_LATENCY_TIMER_REQUEST,
+ FTDI_SIO_GET_LATENCY_TIMER_REQUEST_TYPE,
+ 0, priv->interface,
+ (char*) &latency, 1, WDR_TIMEOUT);
+
+ if (rv < 0) {
+ dev_err(dev, "Unable to read latency timer: %i", rv);
+ return -EIO;
+ }
+ return sprintf(buf, "%i\n", latency);
+}
+
+/* Write a new value of the latency timer, in units of milliseconds. */
+ssize_t store_latency_timer(struct device *dev, const char *valbuf, size_t count)
+{
+ struct usb_serial_port *port = to_usb_serial_port(dev);
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+ struct usb_device *udev;
+ char buf[1];
+ int v = simple_strtoul(valbuf, NULL, 10);
+ int rv = 0;
+
+ udev = to_usb_device(dev);
+
+ dbg("%s: setting latency timer = %i", __FUNCTION__, v);
+
+ rv = usb_control_msg(udev,
+ usb_sndctrlpipe(udev, 0),
+ FTDI_SIO_SET_LATENCY_TIMER_REQUEST,
+ FTDI_SIO_SET_LATENCY_TIMER_REQUEST_TYPE,
+ v, priv->interface,
+ buf, 0, WDR_TIMEOUT);
+
+ if (rv < 0) {
+ dev_err(dev, "Unable to write latency timer: %i", rv);
+ return -EIO;
+ }
+
+ return count;
+}
+
+/* Write an event character directly to the FTDI register. The ASCII
+ value is in the low 8 bits, with the enable bit in the 9th bit. */
+ssize_t store_event_char(struct device *dev, const char *valbuf, size_t count)
+{
+ struct usb_serial_port *port = to_usb_serial_port(dev);
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+ struct usb_device *udev;
+ char buf[1];
+ int v = simple_strtoul(valbuf, NULL, 10);
+ int rv = 0;
+
+ udev = to_usb_device(dev);
+
+ dbg("%s: setting event char = %i", __FUNCTION__, v);
+
+ rv = usb_control_msg(udev,
+ usb_sndctrlpipe(udev, 0),
+ FTDI_SIO_SET_EVENT_CHAR_REQUEST,
+ FTDI_SIO_SET_EVENT_CHAR_REQUEST_TYPE,
+ v, priv->interface,
+ buf, 0, WDR_TIMEOUT);
+
+ if (rv < 0) {
+ dbg("Unable to write event character: %i", rv);
+ return -EIO;
+ }
+
+ return count;
+}
+
+static DEVICE_ATTR(latency_timer, S_IWUGO | S_IRUGO, show_latency_timer, store_latency_timer);
+static DEVICE_ATTR(event_char, S_IWUGO, NULL, store_event_char);
+
+void create_sysfs_attrs(struct usb_serial *serial)
+{
+ struct ftdi_private *priv;
+ struct usb_device *udev;
+
+ dbg("%s",__FUNCTION__);
+
+ priv = usb_get_serial_port_data(serial->port[0]);
+ udev = serial->dev;
+
+ if (priv->chip_type == FT232BM) {
+ dbg("sysfs attributes for FT232BM");
+ device_create_file(&udev->dev, &dev_attr_event_char);
+ device_create_file(&udev->dev, &dev_attr_latency_timer);
+ }
+}
+
+void remove_sysfs_attrs(struct usb_serial *serial)
+{
+ struct ftdi_private *priv;
+ struct usb_device *udev;
+
+ dbg("%s",__FUNCTION__);
+
+ priv = usb_get_serial_port_data(serial->port[0]);
+ udev = serial->dev;
+
+ if (priv->chip_type == FT232BM) {
+ device_remove_file(&udev->dev, &dev_attr_event_char);
+ device_remove_file(&udev->dev, &dev_attr_latency_timer);
+ }
+
+}
+