[1/2] USB: serial: mos7840: Adjust port settings for read and write registers

[Jackychou <jackychou@asix.com.tw>]

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

In the read/write function, set port 2 independently in the 2-port case.

When setting the offset of port registers, the offset between port 1 and
other ports is different, so port 1 is set independently.
Then in the rest of ports, the port 2 between 2-ports case and 4-ports case
is different, so port 2 in 2-ports case is set independently.

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

 			       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,
@@ -2132,22 +2122,16 @@ 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);

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 88828b4b8c44..92ab68ef08ab 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,