[PATCHv3] USB: serial: mos7840: Add a product ID for the new product

["JackyChou" <jackychou@asix.com.tw>]

From: JackyChou <jackychou@asix.com.tw>

For now, pause to add PID 0x7843 in the driver.

Simplify the processes of some functions.
Such modifications will not affect the old devices and will make
the addition of new product (0x7843) more flexible in the future.

Signed-off-by: JackyChou <jackychou@asix.com.tw>
---
 drivers/usb/serial/mos7840.c | 48 ++++++++++++------------------------
 1 file changed, 16 insertions(+), 32 deletions(-)

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index b42bad85097a..0ca945dce377 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -298,15 +298,10 @@ static int mos7840_set_uart_reg(struct usb_serial_port
*port, __u16 reg,
 	val = val & 0x00ff;
 	/* For the UART control registers, the application number need
 	   to be Or'ed */
-	if (port->serial->num_ports == 4) {
+	if (port->serial->num_ports == 2 && port->port_number != 0)
+		val |= ((__u16)port->port_number + 2) << 8;
+	else
 		val |= ((__u16)port->port_number + 1) << 8;
-	} else {
-		if (port->port_number == 0) {
-			val |= ((__u16)port->port_number + 1) << 8;
-		} else {
-			val |= ((__u16)port->port_number + 2) << 8;
-		}
-	}
 	dev_dbg(&port->dev, "%s application number is %x\n", __func__, val);
 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ,
 			       MCS_WR_RTYPE, val, reg, NULL, 0,
@@ -332,15 +327,10 @@ static int mos7840_get_uart_reg(struct usb_serial_port
*port, __u16 reg,
 		return -ENOMEM;
 
 	/* Wval  is same as application number */
-	if (port->serial->num_ports == 4) {
+	if (port->serial->num_ports == 2 && port->port_number != 0)
+		Wval = ((__u16)port->port_number + 2) << 8;
+	else
 		Wval = ((__u16)port->port_number + 1) << 8;
-	} else {
-		if (port->port_number == 0) {
-			Wval = ((__u16)port->port_number + 1) << 8;
-		} else {
-			Wval = ((__u16)port->port_number + 2) << 8;
-		}
-	}
 	dev_dbg(&port->dev, "%s application number is %x\n", __func__,
Wval);
 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
 			      MCS_RD_RTYPE, Wval, reg, buf,
VENDOR_READ_LENGTH,
@@ -2146,22 +2136,16 @@ static int mos7840_port_probe(struct usb_serial_port
*port)
 		mos7840_port->SpRegOffset = 0x0;
 		mos7840_port->ControlRegOffset = 0x1;
 		mos7840_port->DcrRegOffset = 0x4;
-	} else if ((mos7840_port->port_num == 2) && (serial->num_ports ==
4)) {
-		mos7840_port->SpRegOffset = 0x8;
-		mos7840_port->ControlRegOffset = 0x9;
-		mos7840_port->DcrRegOffset = 0x16;
-	} else if ((mos7840_port->port_num == 2) && (serial->num_ports ==
2)) {
-		mos7840_port->SpRegOffset = 0xa;
-		mos7840_port->ControlRegOffset = 0xb;
-		mos7840_port->DcrRegOffset = 0x19;
-	} else if ((mos7840_port->port_num == 3) && (serial->num_ports ==
4)) {
-		mos7840_port->SpRegOffset = 0xa;
-		mos7840_port->ControlRegOffset = 0xb;
-		mos7840_port->DcrRegOffset = 0x19;
-	} else if ((mos7840_port->port_num == 4) && (serial->num_ports ==
4)) {
-		mos7840_port->SpRegOffset = 0xc;
-		mos7840_port->ControlRegOffset = 0xd;
-		mos7840_port->DcrRegOffset = 0x1c;
+	} else {
+		u8 port_offset;
+
+		if ((mos7840_port->port_num == 2) && (serial->num_ports ==
2))
+			port_offset = 1;
+		else
+			port_offset = mos7840_port->port_num - 2;
+		mos7840_port->SpRegOffset = 0x8 + (2 * port_offset);
+		mos7840_port->ControlRegOffset = 0x9 + (2 * port_offset);
+		mos7840_port->DcrRegOffset = 0x16 + (3 * port_offset);
 	}
 	mos7840_dump_serial_port(port, mos7840_port);
 	mos7840_set_port_private(port, mos7840_port);
-- 
2.17.1