diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 6a50965e23f29498b2055f4ecbf1912eb3628759..2d338737219e1630b01be4147d344ed2eaab8aa5 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -75,6 +75,7 @@ struct ftdi_private { unsigned long last_dtr_rts; /* saved modem control outputs */ wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */ char prev_status, diff_status; /* Used for TIOCMIWAIT */ + char transmit_empty; /* If transmitter is empty or not */ struct usb_serial_port *port; __u16 interface; /* FT2232C, FT2232H or FT4232H port interface (0 for FT232/245) */ @@ -1322,6 +1323,23 @@ static int set_serial_info(struct tty_struct *tty, return 0; } +static int get_lsr_info(struct usb_serial_port *port, + struct serial_struct __user *retinfo) +{ + struct ftdi_private *priv = usb_get_serial_port_data(port); + unsigned int result = 0; + + if (!retinfo) + return -EFAULT; + + if (priv->transmit_empty) + result = TIOCSER_TEMT; + + if (copy_to_user(retinfo, &result, sizeof(unsigned int))) + return -EFAULT; + return 0; +} + /* Determine type of FTDI chip based on USB config and descriptor. */ static void ftdi_determine_type(struct usb_serial_port *port) @@ -1871,6 +1889,12 @@ static int ftdi_process_packet(struct tty_struct *tty, tty_insert_flip_char(tty, 0, TTY_OVERRUN); } + /* save if the transmitter is empty or not */ + if (packet[1] & FTDI_RS_TEMT) + priv->transmit_empty = 1; + else + priv->transmit_empty = 0; + len -= 2; if (!len) return 0; /* status only */ @@ -2234,6 +2258,9 @@ static int ftdi_ioctl(struct tty_struct *tty, struct file *file, } } return 0; + case TIOCSERGETLSR: + return get_lsr_info(port, (struct serial_struct __user *)arg); + break; default: break; }