Re: [PATCH V7 07/11] USB: f81232: implement port_enable function

[Johan Hovold <johan@kernel.org>]

On Tue, Feb 24, 2015 at 06:16:22PM +0800, Peter Hung wrote:
> We put FCR/IER initial step to f81232_port_enable(). When port is open,
> it set MSR interrupt on. Otherwise set it off.
> 
> Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
> ---
>  drivers/usb/serial/f81232.c | 39 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
> index 21f606f..f5c9060 100644
> --- a/drivers/usb/serial/f81232.c
> +++ b/drivers/usb/serial/f81232.c
> @@ -37,6 +37,8 @@ MODULE_DEVICE_TABLE(usb, id_table);
>  #define F81232_SET_REGISTER	0x40
>  
>  #define SERIAL_BASE_ADDRESS	0x0120
> +#define INTERRUPT_ENABLE_REGISTER	(0x01 + SERIAL_BASE_ADDRESS)
> +#define FIFO_CONTROL_REGISTER	(0x02 + SERIAL_BASE_ADDRESS)
>  #define MODEM_CONTROL_REGISTER	(0x04 + SERIAL_BASE_ADDRESS)
>  #define MODEM_STATUS_REGISTER	(0x06 + SERIAL_BASE_ADDRESS)
>  
> @@ -367,6 +369,33 @@ static void f81232_break_ctl(struct tty_struct *tty, int break_state)
>  	 */
>  }
>  
> +static int f81232_port_enable(struct usb_serial_port *port, int enable)

Split this in two functions, enable and disable, since you don't need to
set FCR on close.

> +{
> +	u8 data = 0;
> +	int status;
> +
> +	/* fifo on, trigger8, clear TX/RX*/
> +	data = UART_FCR_TRIGGER_8 | UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR
> +			| UART_FCR_CLEAR_XMIT;

Put the final | before the line break.

> +
> +	status = f81232_set_register(port, FIFO_CONTROL_REGISTER, data);
> +	if (status) {
> +		dev_err(&port->dev, "%s failed to set FCR: %d\n", __func__, status);
> +		return status;
> +	}
> +
> +	/* MSR Interrupt only, LSR will read from Bulk-in odd byte */
> +	data = enable ? UART_IER_MSI : 0;
> +
> +	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER, data);
> +	if (status) {
> +		dev_err(&port->dev, "%s failed to set IER: %d\n", __func__, status);
> +		return status;
> +	}
> +
> +	return 0;
> +}
> +
>  static void f81232_set_termios(struct tty_struct *tty,
>  		struct usb_serial_port *port, struct ktermios *old_termios)
>  {
> @@ -418,6 +447,12 @@ static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
>  {
>  	int result;
>  
> +	result = f81232_port_enable(port, 1);
> +	if (result) {
> +		dev_err(&port->dev, "%s - init fail: %d\n", __func__, result);
> +		return result;

You already log the error in port_enable.

> +	}
> +
>  	/* Setup termios */
>  	if (tty)
>  		f81232_set_termios(tty, port, NULL);
> @@ -440,6 +475,10 @@ static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
>  
>  static void f81232_close(struct usb_serial_port *port)
>  {
> +	int result = f81232_port_enable(port, 0);

Separate the declaration from the function call.

> +	if (result)
> +		dev_err(&port->dev, "%s - init fail: %d\n", __func__, result);
> +

Already logged as well.

>  	usb_serial_generic_close(port);
>  	usb_kill_urb(port->interrupt_in_urb);
>  }

Johan