[PATCH V5 4/8] USB: f81232: implement set_termios

[Peter Hung <hpeter@gmail.com>]

The original driver had do not any h/w change in driver.
This patch implements with configure H/W for
baud/parity/word length/stop bits functional.

Some init step extract to f81232_port_init(), called once with open().
And refine baudrate setting to f81232_set_baudrate()

Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
---
 drivers/usb/serial/f81232.c | 145 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 138 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 9ea498a..06d1eb0 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -31,11 +31,19 @@ static const struct usb_device_id id_table[] = {
 };
 MODULE_DEVICE_TABLE(usb, id_table);
 
+/* Maximum baudrate for F81232 */
+#define F81232_MAX_BAUDRATE 115200L
+
 /* USB Control EP parameter */
 #define F81232_REGISTER_REQUEST 0xA0
 #define F81232_GET_REGISTER 0xc0
+#define F81232_SET_REGISTER 0x40
 
 #define SERIAL_BASE_ADDRESS	   0x0120
+#define RECEIVE_BUFFER_REGISTER    (0x00 + SERIAL_BASE_ADDRESS)
+#define INTERRUPT_ENABLE_REGISTER  (0x01 + SERIAL_BASE_ADDRESS)
+#define FIFO_CONTROL_REGISTER      (0x02 + SERIAL_BASE_ADDRESS)
+#define LINE_CONTROL_REGISTER      (0x03 + SERIAL_BASE_ADDRESS)
 #define MODEM_STATUS_REGISTER      (0x06 + SERIAL_BASE_ADDRESS)
 
 #define CONTROL_DTR			0x01
@@ -61,6 +69,14 @@ struct f81232_private {
 	struct usb_serial_port *port;
 };
 
+static int calc_baud_divisor(u32 baudrate)
+{
+	if (!baudrate)
+		return 0;
+	else
+		return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
+}
+
 static int f81232_get_register(struct usb_serial_port *port,
 							  u16 reg, u8 *data)
 {
@@ -82,6 +98,27 @@ static int f81232_get_register(struct usb_serial_port *port,
 	return status;
 }
 
+static int f81232_set_register(struct usb_serial_port *port,
+							  u16 reg, u8 data)
+{
+	int status;
+	struct usb_device *dev = port->serial->dev;
+
+	status = usb_control_msg(dev,
+			usb_sndctrlpipe(dev, 0),
+			F81232_REGISTER_REQUEST,
+			F81232_SET_REGISTER,
+			reg,
+			0,
+			&data,
+			sizeof(data),
+			USB_CTRL_SET_TIMEOUT);
+	if (status < 0)
+		dev_err(&port->dev, "%s status: %d\n", __func__, status);
+
+	return status;
+}
+
 static void f81232_read_msr(struct usb_serial_port *port)
 {
 	int status;
@@ -247,18 +284,106 @@ static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 	 */
 }
 
+static void f81232_set_baudrate(struct usb_serial_port *port, int baudrate)
+{
+	u8 divisor;
+	int status = 0;
+
+	divisor = calc_baud_divisor(baudrate);
+
+	status = f81232_set_register(port, LINE_CONTROL_REGISTER,
+			 UART_LCR_DLAB); /* DLAB */
+	if (status < 0) {
+		dev_err(&port->dev, "%s status: %d line:%d\n",
+			__func__, status, __LINE__);
+	}
+
+	status = f81232_set_register(port, RECEIVE_BUFFER_REGISTER,
+			 divisor & 0x00ff); /* low */
+	if (status < 0) {
+		dev_err(&port->dev, "%s status: %d line:%d\n",
+			__func__, status, __LINE__);
+	}
+
+	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
+			 (divisor & 0xff00) >> 8); /* high */
+	if (status < 0) {
+		dev_err(&port->dev, "%s status: %d line:%d\n", __func__,
+			status, __LINE__);
+	}
+
+	status = f81232_set_register(port, LINE_CONTROL_REGISTER, 0x00);
+	if (status < 0) {
+		dev_err(&port->dev, "%s status: %d line:%d\n", __func__,
+			status, __LINE__);
+	}
+}
+
+static int f81232_port_init(struct usb_serial_port *port)
+{
+	u8 data;
+	int status = 0;
+
+	/* 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);
+
+	/* MSR Interrupt only, LSR will read from Bulk-in odd byte */
+	data = UART_IER_MSI;
+
+	/* IER */
+	status |= f81232_set_register(port, INTERRUPT_ENABLE_REGISTER, data);
+	if (status < 0) {
+		dev_err(&port->dev, "%s set error: %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)
 {
-	/* FIXME - Stubbed out for now */
+	u8 new_lcr = 0;
+	int status = 0;
 
-	/* Don't change anything if nothing has changed */
-	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
-		return;
+	f81232_set_baudrate(port, tty_get_baud_rate(tty));
+
+	if (C_PARENB(tty)) {
+		new_lcr |= UART_LCR_PARITY;
+
+		if (!C_PARODD(tty))
+			new_lcr |= UART_LCR_EPAR;
+
+		if (C_CMSPAR(tty))
+			new_lcr |= UART_LCR_SPAR;
+	}
+
+	if (C_CSTOPB(tty))
+		new_lcr |= UART_LCR_STOP;
+
+	switch (C_CSIZE(tty)) {
+	case CS5:
+		new_lcr |= UART_LCR_WLEN5;
+		break;
+	case CS6:
+		new_lcr |= UART_LCR_WLEN6;
+		break;
+	case CS7:
+		new_lcr |= UART_LCR_WLEN7;
+		break;
+	default:
+	case CS8:
+		new_lcr |= UART_LCR_WLEN8;
+		break;
+	}
+
+	status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
+	if (status < 0)
+		dev_err(&port->dev, "%s set error: %d\n", __func__, status);
 
-	/* Do the real work here... */
-	if (old_termios)
-		tty_termios_copy_hw(&tty->termios, old_termios);
 }
 
 static int f81232_tiocmget(struct tty_struct *tty)
@@ -278,6 +403,12 @@ static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 {
 	int result;
 
+	result = f81232_port_init(port);
+	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);
-- 
1.9.1