[PATCH V7 06/11] USB: f81232: implement MCR/MSR function

[Peter Hung <hpeter@gmail.com>]

This patch implement relative MCR/MSR function, such like
tiocmget()/tiocmset()/dtr_rts()/carrier_raised()

original f81232_carrier_raised() compared with wrong value UART_DCD.
It's should compared with UART_MSR_DCD.

Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
---
 drivers/usb/serial/f81232.c | 103 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 81 insertions(+), 22 deletions(-)

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 339be30..21f606f 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -37,6 +37,7 @@ MODULE_DEVICE_TABLE(usb, id_table);
 #define F81232_SET_REGISTER	0x40
 
 #define SERIAL_BASE_ADDRESS	0x0120
+#define MODEM_CONTROL_REGISTER	(0x04 + SERIAL_BASE_ADDRESS)
 #define MODEM_STATUS_REGISTER	(0x06 + SERIAL_BASE_ADDRESS)
 
 #define CONTROL_DTR			0x01
@@ -55,7 +56,7 @@ MODULE_DEVICE_TABLE(usb, id_table);
 
 struct f81232_private {
 	struct mutex lock;
-	u8 line_control;
+	u8 modem_control;
 	u8 modem_status;
 	struct work_struct interrupt_work;
 	struct usb_serial_port *port;
@@ -198,6 +199,52 @@ static void f81232_read_msr(struct usb_serial_port *port)
 	wake_up_interruptible(&port->port.delta_msr_wait);
 }
 
+static int f81232_set_mctrl(struct usb_serial_port *port,
+					   unsigned int set, unsigned int clear)
+{
+	u8 urb_value;
+	int status;
+	struct f81232_private *priv = usb_get_serial_port_data(port);
+
+	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0)
+		return 0;	/* no change */
+
+	/* 'set' takes precedence over 'clear' */
+	clear &= ~set;
+
+	/* force enable interrupt with OUT2 */
+	mutex_lock(&priv->lock);
+	urb_value = UART_MCR_OUT2 | priv->modem_control;
+	mutex_unlock(&priv->lock);
+
+	if (clear & TIOCM_DTR)
+		urb_value &= ~UART_MCR_DTR;
+
+	if (clear & TIOCM_RTS)
+		urb_value &= ~UART_MCR_RTS;
+
+	if (set & TIOCM_DTR)
+		urb_value |= UART_MCR_DTR;
+
+	if (set & TIOCM_RTS)
+		urb_value |= UART_MCR_RTS;
+
+	dev_dbg(&port->dev, "%s new:%02x old:%02x\n", __func__,
+			urb_value, priv->modem_control);
+
+	status = f81232_set_register(port, MODEM_CONTROL_REGISTER, urb_value);
+	if (status) {
+		dev_err(&port->dev, "%s set MCR status < 0\n", __func__);
+		return status;
+	} else {
+		mutex_lock(&priv->lock);
+		priv->modem_control = urb_value;
+		mutex_unlock(&priv->lock);
+	}
+
+	return 0;
+}
+
 static void f81232_update_line_status(struct usb_serial_port *port,
 				      unsigned char *data,
 				      size_t actual_length)
@@ -309,12 +356,6 @@ static void f81232_process_read_urb(struct urb *urb)
 	tty_flip_buffer_push(&port->port);
 }
 
-static int set_control_lines(struct usb_device *dev, u8 value)
-{
-	/* FIXME - Stubbed out for now */
-	return 0;
-}
-
 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 {
 	/* FIXME - Stubbed out for now */
@@ -342,15 +383,35 @@ static void f81232_set_termios(struct tty_struct *tty,
 
 static int f81232_tiocmget(struct tty_struct *tty)
 {
-	/* FIXME - Stubbed out for now */
-	return 0;
+	int r;
+	struct usb_serial_port *port = tty->driver_data;
+	struct f81232_private *port_priv = usb_get_serial_port_data(port);
+	u8 mcr, msr;
+
+	/* force get current MSR changed state */
+	f81232_read_msr(port);
+
+	mutex_lock(&port_priv->lock);
+	mcr = port_priv->modem_control;
+	msr = port_priv->modem_status;
+	mutex_unlock(&port_priv->lock);
+
+	r = (mcr & UART_MCR_DTR ? TIOCM_DTR : 0) |
+		(mcr & UART_MCR_RTS ? TIOCM_RTS : 0) |
+		(msr & UART_MSR_CTS ? TIOCM_CTS : 0) |
+		(msr & UART_MSR_DCD ? TIOCM_CAR : 0) |
+		(msr & UART_MSR_RI ? TIOCM_RI : 0) |
+		(msr & UART_MSR_DSR ? TIOCM_DSR : 0);
+
+	return r;
 }
 
 static int f81232_tiocmset(struct tty_struct *tty,
 			unsigned int set, unsigned int clear)
 {
-	/* FIXME - Stubbed out for now */
-	return 0;
+	struct usb_serial_port *port = tty->driver_data;
+
+	return f81232_set_mctrl(port, set, clear);
 }
 
 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
@@ -385,24 +446,22 @@ static void f81232_close(struct usb_serial_port *port)
 
 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 {
-	struct f81232_private *priv = usb_get_serial_port_data(port);
-	u8 control;
-
-	mutex_lock(&priv->lock);
-	/* Change DTR and RTS */
 	if (on)
-		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
+		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
 	else
-		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
-	control = priv->line_control;
-	mutex_unlock(&priv->lock);
-	set_control_lines(port->serial->dev, control);
+		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
 }
 
 static int f81232_carrier_raised(struct usb_serial_port *port)
 {
+	u8 msr;
 	struct f81232_private *priv = usb_get_serial_port_data(port);
-	if (priv->modem_status & UART_DCD)
+
+	mutex_lock(&priv->lock);
+	msr = priv->modem_status;
+	mutex_unlock(&priv->lock);
+
+	if (msr & UART_MSR_DCD)
 		return 1;
 	return 0;
 }
-- 
1.9.1