USB: serial: mos7840: Fixed MCS7820 device attach problem

A MCS7820 device supports two serial ports and a MCS7840 device supports
four serial ports. Both devices use the same driver, but the attach function
in driver was unable to correctly handle the port numbers for MCS7820
device. This problem has been fixed in this patch and this fix has been
verified on x86 Linux kernel 3.2.9 with both MCS7820 and MCS7840 devices.

Signed-off-by: Donald Lee <[e-mail]>
Cc: stable <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/serial/mos7840.c

···
 
 #define CLK_MULTI_REGISTER         ((__u16)(0x02))
 #define CLK_START_VALUE_REGISTER   ((__u16)(0x03))
+#define GPIO_REGISTER              ((__u16)(0x07))
 
 #define SERIAL_LCR_DLAB            ((__u16)(0x0080))
 
···
 	mos7840_port->read_urb = port->read_urb;
 
 	/* set up our bulk in urb */
-
-	usb_fill_bulk_urb(mos7840_port->read_urb,
-			  serial->dev,
-			  usb_rcvbulkpipe(serial->dev,
-					  port->bulk_in_endpointAddress),
-			  port->bulk_in_buffer,
-			  mos7840_port->read_urb->transfer_buffer_length,
-			  mos7840_bulk_in_callback, mos7840_port);
+	if ((serial->num_ports == 2)
+		&& ((((__u16)port->number -
+			(__u16)(port->serial->minor)) % 2) != 0)) {
+		usb_fill_bulk_urb(mos7840_port->read_urb,
+			serial->dev,
+			usb_rcvbulkpipe(serial->dev,
+				(port->bulk_in_endpointAddress) + 2),
+			port->bulk_in_buffer,
+			mos7840_port->read_urb->transfer_buffer_length,
+			mos7840_bulk_in_callback, mos7840_port);
+	} else {
+		usb_fill_bulk_urb(mos7840_port->read_urb,
+			serial->dev,
+			usb_rcvbulkpipe(serial->dev,
+				port->bulk_in_endpointAddress),
+			port->bulk_in_buffer,
+			mos7840_port->read_urb->transfer_buffer_length,
+			mos7840_bulk_in_callback, mos7840_port);
+	}
 
 	dbg("mos7840_open: bulkin endpoint is %d",
 	    port->bulk_in_endpointAddress);
···
 	memcpy(urb->transfer_buffer, current_position, transfer_size);
 
 	/* fill urb with data and submit  */
-	usb_fill_bulk_urb(urb,
-			  serial->dev,
-			  usb_sndbulkpipe(serial->dev,
-					  port->bulk_out_endpointAddress),
-			  urb->transfer_buffer,
-			  transfer_size,
-			  mos7840_bulk_out_data_callback, mos7840_port);
+	if ((serial->num_ports == 2)
+		&& ((((__u16)port->number -
+			(__u16)(port->serial->minor)) % 2) != 0)) {
+		usb_fill_bulk_urb(urb,
+			serial->dev,
+			usb_sndbulkpipe(serial->dev,
+				(port->bulk_out_endpointAddress) + 2),
+			urb->transfer_buffer,
+			transfer_size,
+			mos7840_bulk_out_data_callback, mos7840_port);
+	} else {
+		usb_fill_bulk_urb(urb,
+			serial->dev,
+			usb_sndbulkpipe(serial->dev,
+				port->bulk_out_endpointAddress),
+			urb->transfer_buffer,
+			transfer_size,
+			mos7840_bulk_out_data_callback, mos7840_port);
+	}
 
 	data1 = urb->transfer_buffer;
 	dbg("bulkout endpoint is %d", port->bulk_out_endpointAddress);
···
 
 	} else {
 #ifdef HW_flow_control
-		/ *setting h/w flow control bit to 0 */
+		/* setting h/w flow control bit to 0 */
 		Data = 0xb;
 		mos7840_port->shadowMCR = Data;
 		status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
···
 
 static int mos7840_calc_num_ports(struct usb_serial *serial)
 {
-	int mos7840_num_ports = 0;
+	__u16 Data = 0x00;
+	int ret = 0;
+	int mos7840_num_ports;
 
-	dbg("numberofendpoints: cur %d, alt %d",
-	    (int)serial->interface->cur_altsetting->desc.bNumEndpoints,
-	    (int)serial->interface->altsetting->desc.bNumEndpoints);
-	if (serial->interface->cur_altsetting->desc.bNumEndpoints == 5) {
-		mos7840_num_ports = serial->num_ports = 2;
-	} else if (serial->interface->cur_altsetting->desc.bNumEndpoints == 9) {
+	ret = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+		MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, &Data,
+		VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+
+	if ((Data & 0x01) == 0) {
+		mos7840_num_ports = 2;
+		serial->num_bulk_in = 2;
+		serial->num_bulk_out = 2;
+		serial->num_ports = 2;
+	} else {
+		mos7840_num_ports = 4;
 		serial->num_bulk_in = 4;
 		serial->num_bulk_out = 4;
-		mos7840_num_ports = serial->num_ports = 4;
+		serial->num_ports = 4;
 	}
-	dbg ("mos7840_num_ports = %d", mos7840_num_ports);
+
 	return mos7840_num_ports;
 }