USB: ftdi: support NDI devices

It enhances the driver for FTDI-based USB serial adapters to recognize and
support Northern Digital Inc (NDI) measurement equipment. NDI has been
providing this patch for various kernel flavors for several years and we would
like to see these changes built in to the driver so that our equipement works
without the need for customers to patch the kernel themselves.

The patch makes small modifications to 2 files: ./drivers/usb/serial/ftdi_sio.c
and ./drivers/usb/serial/ftdi_sio.h. It accomplishes 3 things:

1. Define the VID and PIDs to allow the driver to recognize the NDI devices.
2. Map the 19200 baud rate setting to our higher baud rate of 1.2Mb
   We would have chosen to map 38400 to the higher rate, similar to what
   several other vendors have done, but some of our legacy customers actually
   use 38400, therefore we remap 19200 to the higher rate.
3. We set the default transmit latency in the FTDI chip to 1ms for our devices.
   Our devices are typically polled at 60Hz and the default ftdi latency
   seriously affects turn-around time and results in missed data frames. We
   have created a modprobe option that allows this setting to be increased.
   This has proven necessary particularly in some virtualized environments.

Signed-off-by: Martin P. Geleynse <mgeleyns@ndigital.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/usb/serial/ftdi_sio.h b/drivers/usb/serial/ftdi_sio.h
index 62f05e66ddac..36dc7cd3499a 100644
--- a/drivers/usb/serial/ftdi_sio.h
+++ b/drivers/usb/serial/ftdi_sio.h
@@ -740,6 +740,15 @@
 #define FTDI_PYRAMID_PID        0xE6C8  /* Pyramid Appliance Display */
 
 /*
+ * NDI (www.ndigital.com) product ids
+ */
+#define FTDI_NDI_HUC_PID                0xDA70  /* NDI Host USB Converter */
+#define FTDI_NDI_SPECTRA_SCU_PID        0xDA71  /* NDI Spectra SCU */
+#define FTDI_NDI_FUTURE_2_PID           0xDA72  /* NDI future device #2 */
+#define FTDI_NDI_FUTURE_3_PID           0xDA73  /* NDI future device #3 */
+#define FTDI_NDI_AURORA_SCU_PID         0xDA74  /* NDI Aurora SCU */
+
+/*
  * Posiflex inc retail equipment (http://www.posiflex.com.tw)
  */
 #define POSIFLEX_VID            0x0d3a  /* Vendor ID */
@@ -852,9 +861,6 @@
 #define TML_VID                 0x1B91  /* Vendor ID */
 #define TML_USB_SERIAL_PID      0x0064  /* USB - Serial Converter */
 
-/* NDI Polaris System */
-#define FTDI_NDI_HUC_PID        0xDA70
-
 /* Propox devices */
 #define FTDI_PROPOX_JTAGCABLEII_PID     0xD738