text: /*
   * Driver definitions for the FTDI USB Single Port Serial Converter -
   * known as FTDI_SIO (Serial Input/Output application of the chipset)
   *
   * For USB vendor/product IDs (VID/PID), please see ftdi_sio_ids.h
   *
   *
   * The example I have is known as the USC-1000 which is available from
   * http://www.dse.co.nz - cat no XH4214 It looks similar to this:
   * http://www.dansdata.com/usbser.htm but I can't be sure There are other
   * USC-1000s which don't look like my device though so beware!
   *
   * The device is based on the FTDI FT8U100AX chip. It has a DB25 on one side,
   * USB on the other.
   *
   * Thanx to FTDI (http://www.ftdichip.com) for so kindly providing details
   * of the protocol required to talk to the device and ongoing assistence
   * during development.
   *
   * Bill Ryder - bryder@sgi.com formerly of Silicon Graphics, Inc.- wrote the
   * FTDI_SIO implementation.
   *
   */
  
  /* Commands */
  #define FTDI_SIO_RESET			0 /* Reset the port */
  #define FTDI_SIO_MODEM_CTRL		1 /* Set the modem control register */
  #define FTDI_SIO_SET_FLOW_CTRL		2 /* Set flow control register */
  #define FTDI_SIO_SET_BAUD_RATE		3 /* Set baud rate */
  #define FTDI_SIO_SET_DATA		4 /* Set the data characteristics of
  					     the port */
  #define FTDI_SIO_GET_MODEM_STATUS	5 /* Retrieve current value of modem
  					     status register */
  #define FTDI_SIO_SET_EVENT_CHAR		6 /* Set the event character */
  #define FTDI_SIO_SET_ERROR_CHAR		7 /* Set the error character */
  #define FTDI_SIO_SET_LATENCY_TIMER	9 /* Set the latency timer */
  #define FTDI_SIO_GET_LATENCY_TIMER	10 /* Get the latency timer */
  
  /* Interface indices for FT2232, FT2232H and FT4232H devices */
  #define INTERFACE_A		1
  #define INTERFACE_B		2
  #define INTERFACE_C		3
  #define INTERFACE_D		4
  
  /*
   *   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 */
  /* The device this driver is tested with one has only one port */
  #define PIT_SIOB		2 /* SIOB */
  #define PIT_PARALLEL		3 /* Parallel */
  
  /* FTDI_SIO_RESET */
  #define FTDI_SIO_RESET_REQUEST FTDI_SIO_RESET
  #define FTDI_SIO_RESET_REQUEST_TYPE 0x40
  #define FTDI_SIO_RESET_SIO 0
  #define FTDI_SIO_RESET_PURGE_RX 1
  #define FTDI_SIO_RESET_PURGE_TX 2
  
  /*
   * BmRequestType:  0100 0000B
   * bRequest:       FTDI_SIO_RESET
   * wValue:         Control Value
   *                   0 = Reset SIO
   *                   1 = Purge RX buffer
   *                   2 = Purge TX buffer
   * wIndex:         Port
   * wLength:        0
   * Data:           None
   *
   * The Reset SIO command has this effect:
   *
   *    Sets flow control set to 'none'
   *    Event char = $0D
   *    Event trigger = disabled
   *    Purge RX buffer
   *    Purge TX buffer
   *    Clear DTR
   *    Clear RTS
   *    baud and data format not reset
   *
   * The Purge RX and TX buffer commands affect nothing except the buffers
   *
     */
  
  /* FTDI_SIO_SET_BAUDRATE */
  #define FTDI_SIO_SET_BAUDRATE_REQUEST_TYPE 0x40
  #define FTDI_SIO_SET_BAUDRATE_REQUEST 3
  
  /*
   * BmRequestType:  0100 0000B
   * bRequest:       FTDI_SIO_SET_BAUDRATE
   * wValue:         BaudDivisor value - see below
   * wIndex:         Port
   * wLength:        0
   * Data:           None
   * The BaudDivisor values are calculated as follows:
   * - BaseClock is either 12000000 or 48000000 depending on the device.
   *   FIXME: I wish I knew how to detect old chips to select proper base clock!
   * - BaudDivisor is a fixed point number encoded in a funny way.
   *   (--WRONG WAY OF THINKING--)
   *   BaudDivisor is a fixed point number encoded with following bit weighs:
   *   (-2)(-1)(13..0). It is a radical with a denominator of 4, so values
   *   end with 0.0 (00...), 0.25 (10...), 0.5 (01...), and 0.75 (11...).
   *   (--THE REALITY--)
   *   The both-bits-set has quite different meaning from 0.75 - the chip
   *   designers have decided it to mean 0.125 instead of 0.75.
   *   This info looked up in FTDI application note "FT8U232 DEVICES \ Data Rates
   *   and Flow Control Consideration for USB to RS232".
   * - BaudDivisor = (BaseClock / 16) / BaudRate, where the (=) operation should
   *   automagically re-encode the resulting value to take fractions into
   *   consideration.
   * As all values are integers, some bit twiddling is in order:
   *   BaudDivisor = (BaseClock / 16 / BaudRate) |
   *   (((BaseClock / 2 / BaudRate) & 4) ? 0x4000    // 0.5
   *    : ((BaseClock / 2 / BaudRate) & 2) ? 0x8000  // 0.25
   *    : ((BaseClock / 2 / BaudRate) & 1) ? 0xc000  // 0.125
   *    : 0)
   *
   * For the FT232BM, a 17th divisor bit was introduced to encode the multiples
   * of 0.125 missing from the FT8U232AM.  Bits 16 to 14 are coded as follows
   * (the first four codes are the same as for the FT8U232AM, where bit 16 is
   * always 0):
   *   000 - add .000 to divisor
   *   001 - add .500 to divisor
   *   010 - add .250 to divisor
   *   011 - add .125 to divisor
   *   100 - add .375 to divisor
   *   101 - add .625 to divisor
   *   110 - add .750 to divisor
   *   111 - add .875 to divisor
   * Bits 15 to 0 of the 17-bit divisor are placed in the urb value.  Bit 16 is
   * placed in bit 0 of the urb index.
   *
   * Note that there are a couple of special cases to support the highest baud
   * rates.  If the calculated divisor value is 1, this needs to be replaced with
   * 0.  Additionally for the FT232BM, if the calculated divisor value is 0x4001
   * (1.5), this needs to be replaced with 0x0001 (1) (but this divisor value is
   * not supported by the FT8U232AM).
   */
  
  enum ftdi_chip_type {
  	SIO = 1,
  	FT8U232AM = 2,
  	FT232BM = 3,
  	FT2232C = 4,
  	FT232RL = 5,
  	FT2232H = 6,
  	FT4232H = 7,
  	FT232H  = 8,
  	FTX     = 9,
  };
  
  enum ftdi_sio_baudrate {
  	ftdi_sio_b300 = 0,
  	ftdi_sio_b600 = 1,
  	ftdi_sio_b1200 = 2,
  	ftdi_sio_b2400 = 3,
  	ftdi_sio_b4800 = 4,
  	ftdi_sio_b9600 = 5,
  	ftdi_sio_b19200 = 6,
  	ftdi_sio_b38400 = 7,
  	ftdi_sio_b57600 = 8,
  	ftdi_sio_b115200 = 9
  };
  
  /*
   * The ftdi_8U232AM_xxMHz_byyy constants have been removed. The encoded divisor
   * values are calculated internally.
   */
  #define FTDI_SIO_SET_DATA_REQUEST	FTDI_SIO_SET_DATA
  #define FTDI_SIO_SET_DATA_REQUEST_TYPE	0x40
  #define FTDI_SIO_SET_DATA_PARITY_NONE	(0x0 << 8)
  #define FTDI_SIO_SET_DATA_PARITY_ODD	(0x1 << 8)
  #define FTDI_SIO_SET_DATA_PARITY_EVEN	(0x2 << 8)
  #define FTDI_SIO_SET_DATA_PARITY_MARK	(0x3 << 8)
  #define FTDI_SIO_SET_DATA_PARITY_SPACE	(0x4 << 8)
  #define FTDI_SIO_SET_DATA_STOP_BITS_1	(0x0 << 11)
  #define FTDI_SIO_SET_DATA_STOP_BITS_15	(0x1 << 11)
  #define FTDI_SIO_SET_DATA_STOP_BITS_2	(0x2 << 11)
  #define FTDI_SIO_SET_BREAK		(0x1 << 14)
  /* FTDI_SIO_SET_DATA */
  
  /*
   * BmRequestType:  0100 0000B
   * bRequest:       FTDI_SIO_SET_DATA
   * wValue:         Data characteristics (see below)
   * wIndex:         Port
   * wLength:        0
   * Data:           No
   *
   * Data characteristics
   *
   *   B0..7   Number of data bits
   *   B8..10  Parity
   *           0 = None
   *           1 = Odd
   *           2 = Even
   *           3 = Mark
   *           4 = Space
   *   B11..13 Stop Bits
   *           0 = 1
   *           1 = 1.5
   *           2 = 2
   *   B14
   *           1 = TX ON (break)
   *           0 = TX OFF (normal state)
   *   B15 Reserved
   *
   */
  
  /* FTDI_SIO_MODEM_CTRL */
  #define FTDI_SIO_SET_MODEM_CTRL_REQUEST_TYPE 0x40
  #define FTDI_SIO_SET_MODEM_CTRL_REQUEST FTDI_SIO_MODEM_CTRL
  
  /*
   * BmRequestType:   0100 0000B
   * bRequest:        FTDI_SIO_MODEM_CTRL
   * wValue:          ControlValue (see below)
   * wIndex:          Port
   * wLength:         0
   * Data:            None
   *
   * NOTE: If the device is in RTS/CTS flow control, the RTS set by this
   * command will be IGNORED without an error being returned
   * Also - you can not set DTR and RTS with one control message
   */
  
  #define FTDI_SIO_SET_DTR_MASK 0x1
  #define FTDI_SIO_SET_DTR_HIGH (1 | (FTDI_SIO_SET_DTR_MASK  << 8))
  #define FTDI_SIO_SET_DTR_LOW  (0 | (FTDI_SIO_SET_DTR_MASK  << 8))
  #define FTDI_SIO_SET_RTS_MASK 0x2
  #define FTDI_SIO_SET_RTS_HIGH (2 | (FTDI_SIO_SET_RTS_MASK << 8))
  #define FTDI_SIO_SET_RTS_LOW (0 | (FTDI_SIO_SET_RTS_MASK << 8))
  
  /*
   * ControlValue
   * B0    DTR state
   *          0 = reset
   *          1 = set
   * B1    RTS state
   *          0 = reset
   *          1 = set
   * B2..7 Reserved
   * B8    DTR state enable
   *          0 = ignore
   *          1 = use DTR state
   * B9    RTS state enable
   *          0 = ignore
   *          1 = use RTS state
   * B10..15 Reserved
   */
  
  /* FTDI_SIO_SET_FLOW_CTRL */
  #define FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE 0x40
  #define FTDI_SIO_SET_FLOW_CTRL_REQUEST FTDI_SIO_SET_FLOW_CTRL
  #define FTDI_SIO_DISABLE_FLOW_CTRL 0x0
  #define FTDI_SIO_RTS_CTS_HS (0x1 << 8)
  #define FTDI_SIO_DTR_DSR_HS (0x2 << 8)
  #define FTDI_SIO_XON_XOFF_HS (0x4 << 8)
  /*
   *   BmRequestType:  0100 0000b
   *   bRequest:       FTDI_SIO_SET_FLOW_CTRL
   *   wValue:         Xoff/Xon
   *   wIndex:         Protocol/Port - hIndex is protocol / lIndex is port
   *   wLength:        0
   *   Data:           None
   *
   * hIndex protocol is:
   *   B0 Output handshaking using RTS/CTS
   *       0 = disabled
   *       1 = enabled
   *   B1 Output handshaking using DTR/DSR
   *       0 = disabled
   *       1 = enabled
   *   B2 Xon/Xoff handshaking
   *       0 = disabled
   *       1 = enabled
   *
   * A value of zero in the hIndex field disables handshaking
   *
   * If Xon/Xoff handshaking is specified, the hValue field should contain the
   * XOFF character and the lValue field contains the XON character.
   */
  
  /*
   * FTDI_SIO_GET_LATENCY_TIMER
   *
   * Set the timeout interval. The FTDI collects data from the slave
   * device, transmitting it to the host when either A) 62 bytes are
   * received, or B) the timeout interval has elapsed and the buffer
   * contains at least 1 byte.  Setting this value to a small number
   * can dramatically improve performance for applications which send
   * small packets, since the default value is 16ms.
   */
  #define  FTDI_SIO_GET_LATENCY_TIMER_REQUEST FTDI_SIO_GET_LATENCY_TIMER
  #define  FTDI_SIO_GET_LATENCY_TIMER_REQUEST_TYPE 0xC0
  
  /*
   *  BmRequestType:   1100 0000b
   *  bRequest:        FTDI_SIO_GET_LATENCY_TIMER
   *  wValue:          0
   *  wIndex:          Port
   *  wLength:         0
   *  Data:            latency (on return)
   */
  
  /*
   * FTDI_SIO_SET_LATENCY_TIMER
   *
   * Set the timeout interval. The FTDI collects data from the slave
   * device, transmitting it to the host when either A) 62 bytes are
   * received, or B) the timeout interval has elapsed and the buffer
   * contains at least 1 byte.  Setting this value to a small number
   * can dramatically improve performance for applications which send
   * small packets, since the default value is 16ms.
   */
  #define  FTDI_SIO_SET_LATENCY_TIMER_REQUEST FTDI_SIO_SET_LATENCY_TIMER
  #define  FTDI_SIO_SET_LATENCY_TIMER_REQUEST_TYPE 0x40
  
  /*
   *  BmRequestType:   0100 0000b
   *  bRequest:        FTDI_SIO_SET_LATENCY_TIMER
   *  wValue:          Latency (milliseconds)
   *  wIndex:          Port
   *  wLength:         0
   *  Data:            None
   *
   * wValue:
   *   B0..7   Latency timer
   *   B8..15  0
   *
   */
  
  /*
   * FTDI_SIO_SET_EVENT_CHAR
   *
   * Set the special event character for the specified communications port.
   * If the device sees this character it will immediately return the
   * data read so far - rather than wait 40ms or until 62 bytes are read
   * which is what normally happens.
   */
  
  #define  FTDI_SIO_SET_EVENT_CHAR_REQUEST FTDI_SIO_SET_EVENT_CHAR
  #define  FTDI_SIO_SET_EVENT_CHAR_REQUEST_TYPE 0x40
  
  /*
   *  BmRequestType:   0100 0000b
   *  bRequest:        FTDI_SIO_SET_EVENT_CHAR
   *  wValue:          EventChar
   *  wIndex:          Port
   *  wLength:         0
   *  Data:            None
   *
   * wValue:
   *   B0..7   Event Character
   *   B8      Event Character Processing
   *             0 = disabled
   *             1 = enabled
   *   B9..15  Reserved
   *
   */
  
  /* FTDI_SIO_SET_ERROR_CHAR */
  
  /*
   * Set the parity error replacement character for the specified communications
   * port
   */
  
  /*
   *  BmRequestType:  0100 0000b
   *  bRequest:       FTDI_SIO_SET_EVENT_CHAR
   *  wValue:         Error Char
   *  wIndex:         Port
   *  wLength:        0
   *  Data:           None
   *
   *Error Char
   *  B0..7  Error Character
   *  B8     Error Character Processing
   *           0 = disabled
   *           1 = enabled
   *  B9..15 Reserved
   *
   */
  
  /* FTDI_SIO_GET_MODEM_STATUS */
  /* Retrieve the current value of the modem status register */
  
  #define FTDI_SIO_GET_MODEM_STATUS_REQUEST_TYPE 0xc0
  #define FTDI_SIO_GET_MODEM_STATUS_REQUEST FTDI_SIO_GET_MODEM_STATUS
  #define FTDI_SIO_CTS_MASK 0x10
  #define FTDI_SIO_DSR_MASK 0x20
  #define FTDI_SIO_RI_MASK  0x40
  #define FTDI_SIO_RLSD_MASK 0x80
  /*
   *   BmRequestType:   1100 0000b
   *   bRequest:        FTDI_SIO_GET_MODEM_STATUS
   *   wValue:          zero
   *   wIndex:          Port
   *   wLength:         1
   *   Data:            Status
   *
   * One byte of data is returned
   * B0..3 0
   * B4    CTS
   *         0 = inactive
   *         1 = active
   * B5    DSR
   *         0 = inactive
   *         1 = active
   * B6    Ring Indicator (RI)
   *         0 = inactive
   *         1 = active
   * B7    Receive Line Signal Detect (RLSD)
   *         0 = inactive
   *         1 = active
   */
  
  /* Descriptors returned by the device
   *
   *  Device Descriptor
   *
   * Offset	Field		Size	Value	Description
   * 0	bLength		1	0x12	Size of descriptor in bytes
   * 1	bDescriptorType	1	0x01	DEVICE Descriptor Type
   * 2	bcdUSB		2	0x0110	USB Spec Release Number
   * 4	bDeviceClass	1	0x00	Class Code
   * 5	bDeviceSubClass	1	0x00	SubClass Code
   * 6	bDeviceProtocol	1	0x00	Protocol Code
   * 7	bMaxPacketSize0 1	0x08	Maximum packet size for endpoint 0
   * 8	idVendor	2	0x0403	Vendor ID
   * 10	idProduct	2	0x8372	Product ID (FTDI_SIO_PID)
   * 12	bcdDevice	2	0x0001	Device release number
   * 14	iManufacturer	1	0x01	Index of man. string desc
   * 15	iProduct	1	0x02	Index of prod string desc
   * 16	iSerialNumber	1	0x02	Index of serial nmr string desc
   * 17	bNumConfigurations 1    0x01	Number of possible configurations
   *
   * Configuration Descriptor
   *
   * Offset	Field			Size	Value
   * 0	bLength			1	0x09	Size of descriptor in bytes
   * 1	bDescriptorType		1	0x02	CONFIGURATION Descriptor Type
   * 2	wTotalLength		2	0x0020	Total length of data
   * 4	bNumInterfaces		1	0x01	Number of interfaces supported
   * 5	bConfigurationValue	1	0x01	Argument for SetCOnfiguration() req
   * 6	iConfiguration		1	0x02	Index of config string descriptor
   * 7	bmAttributes		1	0x20	Config characteristics Remote Wakeup
   * 8	MaxPower		1	0x1E	Max power consumption
   *
   * Interface Descriptor
   *
   * Offset	Field			Size	Value
   * 0	bLength			1	0x09	Size of descriptor in bytes
   * 1	bDescriptorType		1	0x04	INTERFACE Descriptor Type
   * 2	bInterfaceNumber	1	0x00	Number of interface
   * 3	bAlternateSetting	1	0x00	Value used to select alternate
   * 4	bNumEndpoints		1	0x02	Number of endpoints
   * 5	bInterfaceClass		1	0xFF	Class Code
   * 6	bInterfaceSubClass	1	0xFF	Subclass Code
   * 7	bInterfaceProtocol	1	0xFF	Protocol Code
   * 8	iInterface		1	0x02	Index of interface string description
   *
   * IN Endpoint Descriptor
   *
   * Offset	Field			Size	Value
   * 0	bLength			1	0x07	Size of descriptor in bytes
   * 1	bDescriptorType		1	0x05	ENDPOINT descriptor type
   * 2	bEndpointAddress	1	0x82	Address of endpoint
   * 3	bmAttributes		1	0x02	Endpoint attributes - Bulk
   * 4	bNumEndpoints		2	0x0040	maximum packet size
   * 5	bInterval		1	0x00	Interval for polling endpoint
   *
   * OUT Endpoint Descriptor
   *
   * Offset	Field			Size	Value
   * 0	bLength			1	0x07	Size of descriptor in bytes
   * 1	bDescriptorType		1	0x05	ENDPOINT descriptor type
   * 2	bEndpointAddress	1	0x02	Address of endpoint
   * 3	bmAttributes		1	0x02	Endpoint attributes - Bulk
   * 4	bNumEndpoints		2	0x0040	maximum packet size
   * 5	bInterval		1	0x00	Interval for polling endpoint
   *
   * DATA FORMAT
   *
   * IN Endpoint
   *
   * The device reserves the first two bytes of data on this endpoint to contain
   * the current values of the modem and line status registers. In the absence of
   * data, the device generates a message consisting of these two status bytes
   * every 40 ms
   *
   * Byte 0: Modem Status
   *
   * Offset	Description
   * B0	Reserved - must be 1
   * B1	Reserved - must be 0
   * B2	Reserved - must be 0
   * B3	Reserved - must be 0
   * B4	Clear to Send (CTS)
   * B5	Data Set Ready (DSR)
   * B6	Ring Indicator (RI)
   * B7	Receive Line Signal Detect (RLSD)
   *
   * Byte 1: Line Status
   *
   * Offset	Description
   * B0	Data Ready (DR)
   * B1	Overrun Error (OE)
   * B2	Parity Error (PE)
   * B3	Framing Error (FE)
   * B4	Break Interrupt (BI)
   * B5	Transmitter Holding Register (THRE)
   * B6	Transmitter Empty (TEMT)
   * B7	Error in RCVR FIFO
   *
   */
  #define FTDI_RS0_CTS	(1 << 4)
  #define FTDI_RS0_DSR	(1 << 5)
  #define FTDI_RS0_RI	(1 << 6)
  #define FTDI_RS0_RLSD	(1 << 7)
  
  #define FTDI_RS_DR	1
  #define FTDI_RS_OE	(1<<1)
  #define FTDI_RS_PE	(1<<2)
  #define FTDI_RS_FE	(1<<3)
  #define FTDI_RS_BI	(1<<4)
  #define FTDI_RS_THRE	(1<<5)
  #define FTDI_RS_TEMT	(1<<6)
  #define FTDI_RS_FIFO	(1<<7)
  
  /*
   * OUT Endpoint
   *
   * This device reserves the first bytes of data on this endpoint contain the
   * length and port identifier of the message. For the FTDI USB Serial converter
   * the port identifier is always 1.
   *
   * Byte 0: Line Status
   *
   * Offset	Description
   * B0	Reserved - must be 1
   * B1	Reserved - must be 0
   * B2..7	Length of message - (not including Byte 0)
   *
   */
  