[PATCH] USB: Add support for FT2232C chip to ftdi_sio

This patch adds support for the FTDI FT2232C USB to dual serial port
converter to the ftdi_sio driver.

The patch is based on a fork of the 2.4 ftdi_sio driver by Steven
Turner of FTDI, and a preliminary port of these changes to the 2.6
ftdi_sio driver by Rus V. Brushkoff.  I've tidied it up and fixed a
couple of things.

I don't have a FT2232C to test it with, but Steven Turner of FTDI
has tested it.  He mentioned a couple of known problems with the
driver, but nothing to do with this patch.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/serial/ftdi_sio.h

@@ -26,6 +26,7 @@
 #define FTDI_SIO_PID	0x8372	/* Product Id SIO application of 8U100AX  */
 #define FTDI_8U232AM_PID 0x6001 /* Similar device to SIO above */
 #define FTDI_8U232AM_ALT_PID 0x6006 /* FTDI's alternate PID for above */
+#define FTDI_8U2232C_PID 0x6010 /* Dual channel device */
 #define FTDI_RELAIS_PID	0xFA10  /* Relais device from Rudolf Gugler */
 #define FTDI_NF_RIC_VID	0x0DCD	/* Vendor Id */
 #define FTDI_NF_RIC_PID	0x0001	/* Product Id */
@@ -234,6 +235,21 @@
 #define FTDI_SIO_SET_EVENT_CHAR	6 /* Set the event character */
 #define FTDI_SIO_SET_ERROR_CHAR	7 /* Set the error character */
 
+/* Port interface code for FT2232C */
+#define INTERFACE_A		1
+#define INTERFACE_B		2
+
+
+/*
+ *   BmRequestType:  1100 0000b
+ *   bRequest:       FTDI_E2_READ
+ *   wValue:         0
+ *   wIndex:         Address of word to read
+ *   wLength:        2
+ *   Data:           Will return a word of data from E2Address
+ *
+ */
+
 /* Port Identifier Table */
 #define PIT_DEFAULT 		0 /* SIOA */
 #define PIT_SIOA		1 /* SIOA */
@@ -333,6 +349,7 @@ typedef enum {
 	SIO = 1,
 	FT8U232AM = 2,
 	FT232BM = 3,
+	FT2232C = 4,
 } ftdi_chip_type_t;
 
 typedef enum {