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

[Peter Hung <hpeter@gmail.com>]

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)
+{
+	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;
+
+	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;
+	}
+
 	/* 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);
+	if (result)
+		dev_err(&port->dev, "%s - init fail: %d\n", __func__, result);
+
 	usb_serial_generic_close(port);
 	usb_kill_urb(port->interrupt_in_urb);
 }
-- 
1.9.1