USB: serial: ftdi_sio: add support for TIOCSERGETLSR
Willem-Jan noticed that the ftdi_sio driver did not support the
TIOCSERGETLSR ioctl, and some userspace programs rely on it. This patch
adds the support.
Reported-by: Willem-Jan de Hoog <wdehoog@exalondelft.nl>
Tested-by: Willem-Jan de Hoog <wdehoog@exalondelft.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 6a50965..2d33873 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -75,6 +75,7 @@
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 @@
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 @@
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 @@
}
}
return 0;
+ case TIOCSERGETLSR:
+ return get_lsr_info(port, (struct serial_struct __user *)arg);
+ break;
default:
break;
}