[Ftdi-usb-sio-devel] FIONREAD ioctl (0x54b1)

[[Carlos H.] <ca...@gm...>]

Hello all,

We've recently switched to the following FTDI chip:

Bus 5 Device 3: ID 0403:6001 Future Technology Devices International, Ltd
8-bit FIFO
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0         8
  idVendor           0x0403 Future Technology Devices International, Ltd
  idProduct          0x6001 8-bit FIFO
  bcdDevice            6.00
  iManufacturer           1 FTDI
  iProduct                2 FT232R USB UART
  iSerial                 3 A2001DYM
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           32
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower               90mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass    255 Vendor Specific Subclass
      bInterfaceProtocol    255 Vendor Specific Protocol
      iInterface              2 FT232R USB UART
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
Device Status:     0x0000
  (Bus Powered)

I have legacy software which makes use of the FIONREAD (0x54b1) ioctl to see
how many bytes are available on the FIFO, but by using the ftdi_sio module
on kernel 2.6.19 I'm getting the following error (took from debug output).

Sep 24 11:05:44 carlos kernel: drivers/usb/serial/ftdi_sio.c: ftdi_ioctl cmd
0x541b
Sep 24 11:05:44 carlos kernel: drivers/usb/serial/ftdi_sio.c: ftdi_ioctl arg
not supported - it was 0x541b - check /usr/include/asm/ioctls.h

Is this really not implemented? Could it be done easily? Thanks in advance
for any hints.

-- 
[]'s
Carlos H.