USB: serial: cp210x: add support for TIOCGICOUNT

Enable TIOCGICOUNT to allow reading out the (unused) interrupt counters
and error statistics.

Note that modem-status events are currently left unimplemented as they
appear to be buffered on at least CP2102 and therefore cannot be used to
implement TIOCMIWAIT.

Link: https://lore.kernel.org/r/20200713105517.27796-4-johan@kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 02e4acb..3a65be4 100644 (file)
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -291,6 +291,7 @@ static struct usb_serial_driver cp210x_device = {
        .unthrottle             = usb_serial_generic_unthrottle,
        .tiocmget               = cp210x_tiocmget,
        .tiocmset               = cp210x_tiocmset,
+       .get_icount             = usb_serial_generic_get_icount,
        .attach                 = cp210x_attach,
        .disconnect             = cp210x_disconnect,
        .release                = cp210x_release,