ftdi_sio.c

NP-Convert,usb4口转换器的驱动开发示例.面向Linux.

	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_SIO_startup,
	.shutdown =		ftdi_shutdown,
};

static struct usb_serial_device_type ftdi_8U232AM_device = {
	.owner =		THIS_MODULE,
	.name =			"FTDI 8U232AM Compatible",
	.id_table =		id_table_8U232AM,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_8U232AM_startup,
	.shutdown =		ftdi_shutdown,
};

static struct usb_serial_device_type ftdi_FT232BM_device = {
	.owner =		THIS_MODULE,
	.name =			"FTDI FT232BM Compatible",
	.id_table =		id_table_FT232BM,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_FT232BM_startup,
	.shutdown =		ftdi_shutdown,
};

static struct usb_serial_device_type ftdi_FT2232C_device = {
	.owner =		THIS_MODULE,
	.name =			"FTDI FT2232C Compatible",
	.id_table =		id_table_FT2232C,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_FT2232C_startup,
	.shutdown =		ftdi_shutdown,
};

static struct usb_serial_device_type ftdi_FT232R_device = {
	.owner =		THIS_MODULE,
	.name =			"FTDI FT232R Compatible",
	.id_table =		id_table_FT232R,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_FT232R_startup,
	.shutdown =		ftdi_shutdown,
};

static struct usb_serial_device_type ftdi_USB_UIRT_device = {
	.owner =		THIS_MODULE,
	.name =			"USB-UIRT Infrared Tranceiver",
	.id_table =		id_table_USB_UIRT,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_USB_UIRT_startup,
	.shutdown =		ftdi_shutdown,
};

/* The TIRA1 is based on a  FT232BM which requires a fixed baud rate of 100000
 * and which requires RTS-CTS to be enabled. */
static struct usb_serial_device_type ftdi_HE_TIRA1_device = {
	.owner =		THIS_MODULE,
	.name =			"Home-Electronics TIRA-1 IR Transceiver",
	.id_table =		id_table_HE_TIRA1,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_HE_TIRA1_startup,
	.shutdown =		ftdi_shutdown,
};


static struct usb_serial_device_type ftdi_userdev_device = {
	.owner =		THIS_MODULE,
	.name =			"FTDI SIO compatible",
	.id_table =		id_table_userdev,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_userdev_startup,
	.shutdown =		ftdi_shutdown,
};

#define WDR_TIMEOUT (HZ * 5 ) /* default urb timeout */

/* High and low are for DTR, RTS etc etc */
#define HIGH 1
#define LOW 0

/*
 * ***************************************************************************
 * Utlity functions
 * ***************************************************************************
 */

static unsigned short int ftdi_232am_baud_base_to_divisor(int baud, int base)
{
	unsigned short int divisor;
	int divisor3 = base / 2 / baud; // divisor shifted 3 bits to the left
	if ((divisor3 & 0x7) == 7) divisor3 ++; // round x.7/8 up to x+1
	divisor = divisor3 >> 3;
	divisor3 &= 0x7;
	if (divisor3 == 1) divisor |= 0xc000; else // 0.125
	if (divisor3 >= 4) divisor |= 0x4000; else // 0.5
	if (divisor3 != 0) divisor |= 0x8000;      // 0.25
	if (divisor == 1) divisor = 0;	/* special case for maximum baud rate */
	return divisor;
}

static unsigned short int ftdi_232am_baud_to_divisor(int baud)
{
	 return(ftdi_232am_baud_base_to_divisor(baud, 48000000));
}

static __u32 ftdi_232bm_baud_base_to_divisor(int baud, int base)
{
	static const unsigned char divfrac[8] = { 0, 3, 2, 4, 1, 5, 6, 7 };
	__u32 divisor;
	int divisor3 = base / 2 / baud; // divisor shifted 3 bits to the left
	divisor = divisor3 >> 3;
	divisor |= (__u32)divfrac[divisor3 & 0x7] << 14;
	/* Deal with special cases for highest baud rates. */
	if (divisor == 1) divisor = 0; else	// 1.0
	if (divisor == 0x4001) divisor = 1;	// 1.5
	return divisor;
}

static __u32 ftdi_232bm_baud_to_divisor(int baud)
{
	 return(ftdi_232bm_baud_base_to_divisor(baud, 48000000));
}

static int set_rts(struct usb_serial_port *port, int high_or_low)
{
	struct ftdi_private * priv = (struct ftdi_private *)port->private;
	char buf[1];
	unsigned ftdi_high_or_low;
	if (high_or_low) {
		ftdi_high_or_low = FTDI_SIO_SET_RTS_HIGH;
		priv->last_dtr_rts |= TIOCM_RTS;
	} else {
		ftdi_high_or_low = FTDI_SIO_SET_RTS_LOW;
		priv->last_dtr_rts &= ~TIOCM_RTS;
	}
	return(usb_control_msg(port->serial->dev,
			       usb_sndctrlpipe(port->serial->dev, 0),
			       FTDI_SIO_SET_MODEM_CTRL_REQUEST, 
			       FTDI_SIO_SET_MODEM_CTRL_REQUEST_TYPE,
			       ftdi_high_or_low, priv->interface, 
			       buf, 0, WDR_TIMEOUT));
}


static int set_dtr(struct usb_serial_port *port, int high_or_low)
{
	struct ftdi_private * priv = (struct ftdi_private *)port->private;
	char buf[1];
	unsigned ftdi_high_or_low;
	if (high_or_low) {
		ftdi_high_or_low = FTDI_SIO_SET_DTR_HIGH;
		priv->last_dtr_rts |= TIOCM_DTR;
	} else {
		ftdi_high_or_low = FTDI_SIO_SET_DTR_LOW;
		priv->last_dtr_rts &= ~TIOCM_DTR;
	}
	return(usb_control_msg(port->serial->dev,
			       usb_sndctrlpipe(port->serial->dev, 0),
			       FTDI_SIO_SET_MODEM_CTRL_REQUEST, 
			       FTDI_SIO_SET_MODEM_CTRL_REQUEST_TYPE,
			       ftdi_high_or_low, priv->interface, 
			       buf, 0, WDR_TIMEOUT));
}


static __u32 get_ftdi_divisor(struct usb_serial_port * port);


static int change_speed(struct usb_serial_port *port)
{
	char buf[1];
	struct ftdi_private * priv = (struct ftdi_private *)port->private;
        __u16 urb_value;
	__u16 urb_index;
	__u32 urb_index_value;

	urb_index_value = get_ftdi_divisor(port);
	urb_value = (__u16)urb_index_value;

	if(priv->chip_type == FT2232C) {
		urb_index = (__u16)(urb_index_value >> 8);
		urb_index &= 0xFF00;
		urb_index |= priv->interface;
	} else {
		urb_index = (__u16)(urb_index_value >> 16);
		urb_index |= priv->interface;
	}	
	
	return (usb_control_msg(port->serial->dev,
			    usb_sndctrlpipe(port->serial->dev, 0),
			    FTDI_SIO_SET_BAUDRATE_REQUEST,
			    FTDI_SIO_SET_BAUDRATE_REQUEST_TYPE,
			    urb_value, urb_index,
			    buf, 0, 100) < 0);
}


static __u32 get_ftdi_divisor(struct usb_serial_port * port)
{ /* get_ftdi_divisor */
	
	struct ftdi_private * priv = (struct ftdi_private *)port->private;
	__u32 div_value = 0;
	int div_okay = 1;
	char *chip_name = "";
	int baud;

	/*
	 * The logic involved in setting the baudrate can be cleanly split in 3 steps.
	 * Obtaining the actual baud rate is a little tricky since unix traditionally
	 * somehow ignored the possibility to set non-standard baud rates.
	 * 1. Standard baud rates are set in tty->termios->c_cflag
	 * 2. If these are not enough, you can set any speed using alt_speed as follows:
	 *    - set tty->termios->c_cflag speed to B38400
	 *    - set your real speed in tty->alt_speed; it gets ignored when
	 *      alt_speed==0, (or)
	 *    - call TIOCSSERIAL ioctl with (struct serial_struct) set as follows:
	 *      flags & ASYNC_SPD_MASK == ASYNC_SPD_[HI, VHI, SHI, WARP], this just
	 *      sets alt_speed to (HI: 57600, VHI: 115200, SHI: 230400, WARP: 460800)
	 * ** Steps 1, 2 are done courtesy of tty_get_baud_rate
	 * 3. You can also set baud rate by setting custom divisor as follows
	 *    - set tty->termios->c_cflag speed to B38400
	 *    - call TIOCSSERIAL ioctl with (struct serial_struct) set as follows:
	 *      o flags & ASYNC_SPD_MASK == ASYNC_SPD_CUST
	 *      o custom_divisor set to baud_base / your_new_baudrate
	 * ** Step 3 is done courtesy of code borrowed from serial.c - I should really
	 *    spend some time and separate+move this common code to serial.c, it is
	 *    replicated in nearly every serial driver you see.
	 */

	/* 1. Get the baud rate from the tty settings, this observes alt_speed hack */

	baud = tty_get_baud_rate(port->tty);
	dbg("%s - tty_get_baud_rate reports speed %d", __FUNCTION__, baud);

	/* 2. Observe async-compatible custom_divisor hack, update baudrate if needed */

	if (baud == 38400 &&
	    ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) &&
	     (priv->custom_divisor)) {
		baud = priv->baud_base / priv->custom_divisor;
		dbg("%s - custom divisor %d sets baud rate to %d", __FUNCTION__, priv->custom_divisor, baud);
	}