Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 579 insertions, 0 deletions

diff --git a/drivers/usb/serial/ftdi_sio.h b/drivers/usb/serial/ftdi_sio.h
new file mode 100644
index 0000000000..55ea61264f
--- /dev/null
+++ b/drivers/usb/serial/ftdi_sio.h
@@ -0,0 +1,579 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * 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	0x0a /* Get the latency timer */
+#define FTDI_SIO_SET_BITMODE		0x0b /* Set bitbang mode */
+#define FTDI_SIO_READ_PINS		0x0c /* Read immediate value of pins */
+#define FTDI_SIO_READ_EEPROM		0x90 /* Read EEPROM */
+
+/* Channel indices for FT2232, FT2232H and FT4232H devices */
+#define CHANNEL_A		1
+#define CHANNEL_B		2
+#define CHANNEL_C		3
+#define CHANNEL_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_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 ((FTDI_SIO_SET_DTR_MASK  << 8) | 1)
+#define FTDI_SIO_SET_DTR_LOW  ((FTDI_SIO_SET_DTR_MASK  << 8) | 0)
+#define FTDI_SIO_SET_RTS_MASK 0x2
+#define FTDI_SIO_SET_RTS_HIGH ((FTDI_SIO_SET_RTS_MASK << 8) | 2)
+#define FTDI_SIO_SET_RTS_LOW  ((FTDI_SIO_SET_RTS_MASK << 8) | 0)
+
+/*
+ * 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
+ * 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
+ * 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
+ */
+
+/* FTDI_SIO_SET_BITMODE */
+#define FTDI_SIO_SET_BITMODE_REQUEST_TYPE 0x40
+#define FTDI_SIO_SET_BITMODE_REQUEST FTDI_SIO_SET_BITMODE
+
+/* Possible bitmodes for FTDI_SIO_SET_BITMODE_REQUEST */
+#define FTDI_SIO_BITMODE_RESET		0x00
+#define FTDI_SIO_BITMODE_CBUS		0x20
+
+/* FTDI_SIO_READ_PINS */
+#define FTDI_SIO_READ_PINS_REQUEST_TYPE 0xc0
+#define FTDI_SIO_READ_PINS_REQUEST FTDI_SIO_READ_PINS
+
+/*
+ * FTDI_SIO_READ_EEPROM
+ *
+ * EEPROM format found in FTDI AN_201, "FT-X MTP memory Configuration",
+ * http://www.ftdichip.com/Support/Documents/AppNotes/AN_201_FT-X%20MTP%20Memory%20Configuration.pdf
+ */
+#define FTDI_SIO_READ_EEPROM_REQUEST_TYPE 0xc0
+#define FTDI_SIO_READ_EEPROM_REQUEST FTDI_SIO_READ_EEPROM
+
+#define FTDI_FTX_CBUS_MUX_GPIO		0x8
+#define FTDI_FT232R_CBUS_MUX_GPIO	0xa
+
+
+/* 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)
+ *
+ */