[PATCH v4 6/7] usb: serial: implement MCR/MSR function for F81232

[Peter Hung <hpeter@gmail.com>]

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

The update_mctrl() replace set_control_lines() to do MCR control
so we clean-up the set_control_lines() function.

Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
---
 drivers/usb/serial/f81232.c | 105 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 83 insertions(+), 22 deletions(-)

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 248f40d..0ed7e36 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -38,11 +38,7 @@ MODULE_DEVICE_TABLE(usb, id_table);
 #define UART_STATE_TRANSIENT_MASK	0x74
 #define UART_DCD			0x01
 #define UART_DSR			0x02
-#define UART_BREAK_ERROR		0x04
 #define UART_RING			0x08
-#define UART_FRAME_ERROR		0x10
-#define UART_PARITY_ERROR		0x20
-#define UART_OVERRUN_ERROR		0x40
 #define UART_CTS			0x80
 
 #define REGISTER_REQUEST 0xA0
@@ -55,6 +51,7 @@ MODULE_DEVICE_TABLE(usb, id_table);
 #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_CONTROL_REGISTER     (0x04 + SERIAL_BASE_ADDRESS)
 #define MODEM_STATUS_REGISTER      (0x06 + SERIAL_BASE_ADDRESS)
 struct f81232_private {
 	spinlock_t lock;
@@ -165,6 +162,62 @@ static void f81232_read_msr(struct f81232_private *priv)
 
 	dev_dbg(&dev->dev, "%s: %x\n", __func__, priv->line_status);
 }
+
+static inline int update_mctrl(struct f81232_private *port_priv,
+					   unsigned int set, unsigned int clear)
+{
+	struct usb_device *dev = port_priv->port->serial->dev;
+	u8 urb_value;
+	int status;
+	unsigned long flags;
+
+	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
+		dev_dbg(&dev->dev, "%s fail - DTR|RTS %d\n",
+			__func__, __LINE__);
+		return 0;	/* no change */
+	}
+
+	clear &= ~set;	/* 'set' takes precedence over 'clear' */
+	urb_value = 8 | port_priv->line_control;
+
+	if (clear & TIOCM_DTR) {
+		urb_value &= ~UART_MCR_DTR;
+		dev_dbg(&dev->dev, "clear DTR\n");
+	}
+
+	if (clear & TIOCM_RTS) {
+		urb_value &= ~UART_MCR_RTS;
+		dev_dbg(&dev->dev, "clear RTS\n");
+	}
+
+	if (set & TIOCM_DTR) {
+		urb_value |= UART_MCR_DTR;
+		dev_dbg(&dev->dev, "set DTR\n");
+	}
+
+	if (set & TIOCM_RTS) {
+		urb_value |= UART_MCR_RTS;
+		dev_dbg(&dev->dev, "set RTS\n");
+	}
+
+	dev_dbg(&dev->dev, "%s n:%x o:%x\n", __func__, urb_value,
+			port_priv->line_control);
+
+	status = f81232_set_register(dev, MODEM_CONTROL_REGISTER, urb_value);
+
+	if (status < 0) {
+		dev_dbg(&dev->dev, "%s read MSR status < 0\n", __func__);
+	} else {
+		spin_lock_irqsave(&port_priv->lock, flags);
+		port_priv->line_control = urb_value;
+		spin_unlock_irqrestore(&port_priv->lock, flags);
+	}
+
+	f81232_read_msr(port_priv);
+
+	return status;
+}
+
 static void f81232_update_line_status(struct usb_serial_port *port,
 				      unsigned char *data,
 				      unsigned int actual_length)
@@ -261,12 +314,6 @@ static void f81232_process_read_urb(struct urb *urb)
 
 }
 
-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 */
@@ -383,14 +430,35 @@ 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);
+	unsigned long flags;
+	u8 mcr, msr;
+
+	spin_lock_irqsave(&port_priv->lock, flags);
+	mcr = port_priv->line_control;
+	msr = port_priv->line_status;
+	spin_unlock_irqrestore(&port_priv->lock, flags);
+
+	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 */
+	struct usb_serial_port *port = tty->driver_data;
+	struct f81232_private *port_priv =
+		usb_get_serial_port_data(port);
+
+	update_mctrl(port_priv, set, clear);
 	return 0;
 }
 
@@ -427,18 +495,11 @@ 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);
-	unsigned long flags;
-	u8 control;
 
-	spin_lock_irqsave(&priv->lock, flags);
-	/* Change DTR and RTS */
 	if (on)
-		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
+		update_mctrl(priv, TIOCM_DTR | TIOCM_RTS, 0);
 	else
-		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
-	control = priv->line_control;
-	spin_unlock_irqrestore(&priv->lock, flags);
-	set_control_lines(port->serial->dev, control);
+		update_mctrl(priv, 0, TIOCM_DTR | TIOCM_RTS);
 }
 
 static int f81232_carrier_raised(struct usb_serial_port *port)
-- 
1.9.1