On Thu, Jun 06, 2019 at 10:54:14AM +0800, Ji-Ze Hong (Peter Hong) wrote:
> Add tx_empty() function for F81232 & F81534A series.
>
> Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@xxxxxxxxx>
> ---
> drivers/usb/serial/f81232.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
> index e9470fb0d691..7d1ec8f9d168 100644
> --- a/drivers/usb/serial/f81232.c
> +++ b/drivers/usb/serial/f81232.c
> @@ -850,6 +850,24 @@ static void f81232_dtr_rts(struct usb_serial_port *port, int on)
> f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
> }
>
> +static bool f81232_tx_empty(struct usb_serial_port *port)
> +{
> + int status;
> + u8 tmp;
> + u8 both_empty = UART_LSR_TEMT | UART_LSR_THRE;
Doesn't TEMT being set imply that THRE is set? So you only need to check
the former?
> +
> + status = f81232_get_register(port, LINE_STATUS_REGISTER, &tmp);
> + if (status) {
> + dev_err(&port->dev, "get LSR status failed: %d\n", status);
> + return false;
> + }
> +
> + if ((tmp & both_empty) != both_empty)
> + return false;
> +
> + return true;
> +}
> +
> static int f81232_carrier_raised(struct usb_serial_port *port)
> {
> u8 msr;
> @@ -1279,6 +1297,7 @@ static struct usb_serial_driver f81232_device = {
> .tiocmget = f81232_tiocmget,
> .tiocmset = f81232_tiocmset,
> .tiocmiwait = usb_serial_generic_tiocmiwait,
> + .tx_empty = f81232_tx_empty,
> .process_read_urb = f81232_read_urb_proxy,
> .read_int_callback = f81232_read_int_callback,
> .port_probe = f81232_port_probe,
Johan
