diff options
Diffstat (limited to 'drivers/usb/serial')
| -rw-r--r-- | drivers/usb/serial/ftdi_sio.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index be845873e23d..381515572235 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -923,6 +923,7 @@ static int ftdi_get_icount(struct tty_struct *tty, static int ftdi_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg); static void ftdi_break_ctl(struct tty_struct *tty, int break_state); +static int ftdi_chars_in_buffer(struct tty_struct *tty); static unsigned short int ftdi_232am_baud_base_to_divisor(int baud, int base); static unsigned short int ftdi_232am_baud_to_divisor(int baud); @@ -957,6 +958,7 @@ static struct usb_serial_driver ftdi_sio_device = { .ioctl = ftdi_ioctl, .set_termios = ftdi_set_termios, .break_ctl = ftdi_break_ctl, + .chars_in_buffer = ftdi_chars_in_buffer, }; static struct usb_serial_driver * const serial_drivers[] = { @@ -2089,6 +2091,64 @@ static void ftdi_break_ctl(struct tty_struct *tty, int break_state) } +static int ftdi_chars_in_buffer(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + struct ftdi_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + int chars; + unsigned char *buf; + int ret; + + /* Check software buffer (code from + * usb_serial_generic_chars_in_buffer()) */ + spin_lock_irqsave(&port->lock, flags); + chars = kfifo_len(&port->write_fifo) + port->tx_bytes; + spin_unlock_irqrestore(&port->lock, flags); + + /* Check hardware buffer */ + switch (priv->chip_type) { + case FT8U232AM: + case FT232BM: + case FT2232C: + case FT232RL: + case FT2232H: + case FT4232H: + case FT232H: + case FTX: + break; + case SIO: + default: + return chars; + } + + buf = kmalloc(2, GFP_KERNEL); + if (!buf) { + dev_err(&port->dev, "kmalloc failed"); + return chars; + } + + ret = usb_control_msg(port->serial->dev, + usb_rcvctrlpipe(port->serial->dev, 0), + FTDI_SIO_GET_MODEM_STATUS_REQUEST, + FTDI_SIO_GET_MODEM_STATUS_REQUEST_TYPE, + 0, priv->interface, + buf, 2, WDR_TIMEOUT); + + if (ret < 2) { + dev_err(&port->dev, "Unable to read modem and line status: " + "%i\n", ret); + goto chars_in_buffer_out; + } + + if (!(buf[1] & FTDI_RS_TEMT)) + chars++; + +chars_in_buffer_out: + kfree(buf); + return chars; +} + /* old_termios contains the original termios settings and tty->termios contains * the new setting to be used * WARNING: set_termios calls this with old_termios in kernel space |