diff mbox series

[V2,2/7] USB: serial: f81232: Add tx_empty function

Message ID 20190923022449.10952-3-hpeter+linux_kernel@gmail.com (mailing list archive)
State New, archived
Headers show
Series Add Fintek F81534A series usb-to-serial driver | expand

Commit Message

Ji-Ze Hong (Peter Hong) Sept. 23, 2019, 2:24 a.m. UTC 
Add tx_empty() function for F81232.

Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
---
 drivers/usb/serial/f81232.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

Comments

Johan Hovold Oct. 23, 2019, 9:15 a.m. UTC | #1 
On Mon, Sep 23, 2019 at 10:24:44AM +0800, Ji-Ze Hong (Peter Hong) wrote:
> Add tx_empty() function for F81232.
> 
> Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
> ---
>  drivers/usb/serial/f81232.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
> index c07d376c743d..b42b3738a768 100644
> --- a/drivers/usb/serial/f81232.c
> +++ b/drivers/usb/serial/f81232.c
> @@ -685,6 +685,23 @@ 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;
> +
> +	status = f81232_get_register(port, LINE_STATUS_REGISTER, &tmp);
> +	if (status) {
> +		dev_err(&port->dev, "get LSR status failed: %d\n", status);
> +		return false;

You need to return true here on errors like the other drivers do
(consider a disconnected device where you end up with -ENODEV here).

> +	}
> +
> +	if ((tmp & UART_LSR_TEMT) != UART_LSR_TEMT)
> +		return false;
> +
> +	return true;
> +}

Johan
diff mbox series

Patch

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index c07d376c743d..b42b3738a768 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -685,6 +685,23 @@  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;
+
+	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 & UART_LSR_TEMT) != UART_LSR_TEMT)
+		return false;
+
+	return true;
+}
+
 static int f81232_carrier_raised(struct usb_serial_port *port)
 {
 	u8 msr;
@@ -820,6 +837,7 @@  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_process_read_urb,
 	.read_int_callback =	f81232_read_int_callback,
 	.port_probe =		f81232_port_probe,