cypress_m8.c

usb driver for 2.6.17

/* returns how much space is available in the soft buffer */
static int cypress_write_room(struct usb_serial_port *port)
{
	struct cypress_private *priv = usb_get_serial_port_data(port);
	int room = 0;
	unsigned long flags;

	dbg("%s - port %d", __FUNCTION__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	room = cypress_buf_space_avail(priv->buf);
	spin_unlock_irqrestore(&priv->lock, flags);

	dbg("%s - returns %d", __FUNCTION__, room);
	return room;
}


static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
{
	struct cypress_private *priv = usb_get_serial_port_data(port);
	__u8 status, control;
	unsigned int result = 0;
	unsigned long flags;
	
	dbg("%s - port %d", __FUNCTION__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	control = priv->line_control;
	status = priv->current_status;
	spin_unlock_irqrestore(&priv->lock, flags);

	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
		| ((status & UART_RI)         ? TIOCM_RI  : 0)
		| ((status & UART_CD)         ? TIOCM_CD  : 0);

	dbg("%s - result = %x", __FUNCTION__, result);

	return result;
}


static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
			       unsigned int set, unsigned int clear)
{
	struct cypress_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;
	
	dbg("%s - port %d", __FUNCTION__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	if (set & TIOCM_RTS)
		priv->line_control |= CONTROL_RTS;
	if (set & TIOCM_DTR)
		priv->line_control |= CONTROL_DTR;
	if (clear & TIOCM_RTS)
		priv->line_control &= ~CONTROL_RTS;
	if (clear & TIOCM_DTR)
		priv->line_control &= ~CONTROL_DTR;
	spin_unlock_irqrestore(&priv->lock, flags);

	priv->cmd_ctrl = 1;
	return cypress_write(port, NULL, 0);
}


static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
{
	struct cypress_private *priv = usb_get_serial_port_data(port);

	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);

	switch (cmd) {
		case TIOCGSERIAL:
			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
				return -EFAULT;
			}
			return (0);
			break;
		case TIOCSSERIAL:
			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
				return -EFAULT;
			}
			/* here we need to call cypress_set_termios to invoke the new settings */
			cypress_set_termios(port, &priv->tmp_termios);
			return (0);
			break;
		/* these are called when setting baud rate from gpsd */
		case TCGETS:
			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
				return -EFAULT;
			}
			return (0);
			break;
		case TCSETS:
			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
				return -EFAULT;
			}
			/* here we need to call cypress_set_termios to invoke the new settings */
			cypress_set_termios(port, &priv->tmp_termios);
			return (0);
			break;
		/* This code comes from drivers/char/serial.c and ftdi_sio.c */
		case TIOCMIWAIT:
			while (priv != NULL) {
				interruptible_sleep_on(&priv->delta_msr_wait);
				/* see if a signal did it */
				if (signal_pending(current))
					return -ERESTARTSYS;
				else {
					char diff = priv->diff_status;

					if (diff == 0) {
						return -EIO; /* no change => error */
					}
					
					/* consume all events */
					priv->diff_status = 0;

					/* return 0 if caller wanted to know about these bits */
					if ( ((arg & TIOCM_RNG) && (diff & UART_RI)) ||
					     ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
					     ((arg & TIOCM_CD) && (diff & UART_CD)) ||
					     ((arg & TIOCM_CTS) && (diff & UART_CTS)) ) {
						return 0;
					}
					/* otherwise caller can't care less about what happened,
					 * and so we continue to wait for more events.
					 */
				}
			}
			return 0;
			break;
		default:
			break;
	}

	dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __FUNCTION__, cmd);

	return -ENOIOCTLCMD;
} /* cypress_ioctl */


static void cypress_set_termios (struct usb_serial_port *port,
		struct termios *old_termios)
{
	struct cypress_private *priv = usb_get_serial_port_data(port);
	struct tty_struct *tty;
	int data_bits, stop_bits, parity_type, parity_enable;
	unsigned cflag, iflag, baud_mask;
	unsigned long flags;
	__u8 oldlines;
	int linechange = 0;

	dbg("%s - port %d", __FUNCTION__, port->number);

	tty = port->tty;
	if ((!tty) || (!tty->termios)) {
		dbg("%s - no tty structures", __FUNCTION__);
		return;
	}

	spin_lock_irqsave(&priv->lock, flags);
	if (!priv->termios_initialized) {
		if (priv->chiptype == CT_EARTHMATE) {
			*(tty->termios) = tty_std_termios;
			tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL |
				CLOCAL;
		} else if (priv->chiptype == CT_CYPHIDCOM) {
			*(tty->termios) = tty_std_termios;
			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
				CLOCAL;
		} else if (priv->chiptype == CT_CA42V2) {
			*(tty->termios) = tty_std_termios;
			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
				CLOCAL;
		}
		priv->termios_initialized = 1;
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	cflag = tty->termios->c_cflag;
	iflag = tty->termios->c_iflag;

	/* check if there are new settings */
	if (old_termios) {
		if ((cflag != old_termios->c_cflag) ||
			(RELEVANT_IFLAG(iflag) !=
			 RELEVANT_IFLAG(old_termios->c_iflag))) {
			dbg("%s - attempting to set new termios settings",
					__FUNCTION__);
			/* should make a copy of this in case something goes
			 * wrong in the function, we can restore it */
			spin_lock_irqsave(&priv->lock, flags);
			priv->tmp_termios = *(tty->termios);
			spin_unlock_irqrestore(&priv->lock, flags);
		} else {
			dbg("%s - nothing to do, exiting", __FUNCTION__);
			return;
		}
	} else
		return;

	/* set number of data bits, parity, stop bits */
	/* when parity is disabled the parity type bit is ignored */

	/* 1 means 2 stop bits, 0 means 1 stop bit */
	stop_bits = cflag & CSTOPB ? 1 : 0;

	if (cflag & PARENB) {
		parity_enable = 1;
		/* 1 means odd parity, 0 means even parity */
		parity_type = cflag & PARODD ? 1 : 0;
	} else
		parity_enable = parity_type = 0;

	if (cflag & CSIZE) {
		switch (cflag & CSIZE) {
			case CS5:
				data_bits = 0;
				break;
			case CS6:
				data_bits = 1;
				break;
			case CS7:
				data_bits = 2;
				break;
			case CS8:
				data_bits = 3;
				break;
			default:
				err("%s - CSIZE was set, but not CS5-CS8",
						__FUNCTION__);
				data_bits = 3;
		}
	} else
		data_bits = 3;

	spin_lock_irqsave(&priv->lock, flags);
	oldlines = priv->line_control;
	if ((cflag & CBAUD) == B0) {
		/* drop dtr and rts */
		dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
		baud_mask = B0;
		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
	} else {
		baud_mask = (cflag & CBAUD);
		switch(baud_mask) {
			case B300:
				dbg("%s - setting baud 300bps", __FUNCTION__);
				break;
			case B600:
				dbg("%s - setting baud 600bps", __FUNCTION__);
				break;
			case B1200:
				dbg("%s - setting baud 1200bps", __FUNCTION__);
				break;
			case B2400:
				dbg("%s - setting baud 2400bps", __FUNCTION__);
				break;
			case B4800:
				dbg("%s - setting baud 4800bps", __FUNCTION__);
				break;
			case B9600:
				dbg("%s - setting baud 9600bps", __FUNCTION__);
				break;
			case B19200:
				dbg("%s - setting baud 19200bps", __FUNCTION__);
				break;
			case B38400:
				dbg("%s - setting baud 38400bps", __FUNCTION__);
				break;
			case B57600:
				dbg("%s - setting baud 57600bps", __FUNCTION__);
				break;
			case B115200:
				dbg("%s - setting baud 115200bps", __FUNCTION__);
				break;
			default:
				dbg("%s - unknown masked baud rate", __FUNCTION__);
		}
		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, "
			"%d data_bits (+5)", __FUNCTION__, stop_bits,
			parity_enable, parity_type, data_bits);

	cypress_serial_control(port, baud_mask, data_bits, stop_bits,
			parity_enable, parity_type, 0, CYPRESS_SET_CONFIG);

	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
	 * filled into the private structure this should confirm that all is
	 * working if it returns what we just set */
	cypress_serial_control(port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);

	/* Here we can define custom tty settings for devices; the main tty
	 * termios flag base comes from empeg.c */

	spin_lock_irqsave(&priv->lock, flags);
	if ( (priv->chiptype == CT_EARTHMATE) && (priv->baud_rate == 4800) ) {
		dbg("Using custom termios settings for a baud rate of "
				"4800bps.");
		/* define custom termios settings for NMEA protocol */

		tty->termios->c_iflag /* input modes - */
			&= ~(IGNBRK  /* disable ignore break */
			| BRKINT     /* disable break causes interrupt */
			| PARMRK     /* disable mark parity errors */
			| ISTRIP     /* disable clear high bit of input char */
			| INLCR      /* disable translate NL to CR */
			| IGNCR      /* disable ignore CR */
			| ICRNL      /* disable translate CR to NL */
			| IXON);     /* disable enable XON/XOFF flow control */

		tty->termios->c_oflag /* output modes */
			&= ~OPOST;    /* disable postprocess output char */

		tty->termios->c_lflag /* line discipline modes */
			&= ~(ECHO     /* disable echo input characters */
			| ECHONL      /* disable echo new line */
			| ICANON      /* disable erase, kill, werase, and rprnt
					 special characters */
			| ISIG        /* disable interrupt, quit, and suspend
					 special characters */
			| IEXTEN);    /* disable non-POSIX special characters */
	} /* CT_CYPHIDCOM: Application should handle this for device */

	linechange = (priv->line_control != oldlines);
	spin_unlock_irqrestore(&priv->lock, flags);

	/* if necessary, set lines */
	if (linechange) {
		priv->cmd_ctrl = 1;
		cypress_write(port, NULL, 0);
	}
} /* cypress_set_termios */


/* returns amount of data still left in soft buffer */
static int cypress_chars_in_buffer(struct usb_serial_port *port)
{
	struct cypress_private *priv = usb_get_serial_port_data(port);
	int chars = 0;
	unsigned long flags;

	dbg("%s - port %d", __FUNCTION__, port->number);
	
	spin_lock_irqsave(&priv->lock, flags);
	chars = cypress_buf_data_avail(priv->buf);
	spin_unlock_irqrestore(&priv->lock, flags);

	dbg("%s - returns %d", __FUNCTION__, chars);
	return chars;
}


static void cypress_throttle (struct usb_serial_port *port)
{
	struct cypress_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	dbg("%s - port %d", __FUNCTION__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	priv->rx_flags = THROTTLED;
	spin_unlock_irqrestore(&priv->lock, flags);
}


static void cypress_unthrottle (struct usb_serial_port *port)
{
	struct cypress_private *priv = usb_get_serial_port_data(port);
	int actually_throttled, result;
	unsigned long flags;

	dbg("%s - port %d", __FUNCTION__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
	priv->rx_flags = 0;
	spin_unlock_irqrestore(&priv->lock, flags);

	if (actually_throttled) {
		port->interrupt_in_urb->dev = port->serial->dev;

		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
		if (result)
			dev_err(&port->dev, "%s - failed submitting read urb, "
					"error %d\n", __FUNCTION__, result);
	}
}


static void cypress_read_int_callback(struct urb *urb, struct pt_regs *regs)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct cypress_private *priv = usb_get_serial_port_data(port);
	struct tty_struct *tty;
	unsigned char *data = urb->transfer_buffer;
	unsigned long flags;
	char tty_flag = TTY_NORMAL;
	int havedata = 0;
	int bytes = 0;
	int result;
	int i = 0;

	dbg("%s - port %d", __FUNCTION__, port->number);