cypress_m8.c

linux-2.6.15.6

	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);

	if (urb->status) {
		dbg("%s - nonzero read status received: %d", __FUNCTION__,
				urb->status);
		return;
	}

	spin_lock_irqsave(&priv->lock, flags);
	if (priv->rx_flags & THROTTLED) {
		dbg("%s - now throttling", __FUNCTION__);
		priv->rx_flags |= ACTUALLY_THROTTLED;
		spin_unlock_irqrestore(&priv->lock, flags);
		return;
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	tty = port->tty;
	if (!tty) {
		dbg("%s - bad tty pointer - exiting", __FUNCTION__);
		return;
	}

	spin_lock_irqsave(&priv->lock, flags);
	switch(urb->actual_length) {
		case 32:
			/* This is for the CY7C64013... */
			priv->current_status = data[0] & 0xF8;
			bytes = data[1] + 2;
			i = 2;
			if (bytes > 2)
				havedata = 1;
			break;
		case 8:
			/* This is for the CY7C63743... */
			priv->current_status = data[0] & 0xF8;
			bytes = (data[0] & 0x07) + 1;
			i = 1;
			if (bytes > 1)
				havedata = 1;
			break;
		default:
			dbg("%s - wrong packet size - received %d bytes",
					__FUNCTION__, urb->actual_length);
			spin_unlock_irqrestore(&priv->lock, flags);
			goto continue_read;
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	usb_serial_debug_data (debug, &port->dev, __FUNCTION__,
			urb->actual_length, data);

	spin_lock_irqsave(&priv->lock, flags);
	/* check to see if status has changed */
	if (priv != NULL) {
		if (priv->current_status != priv->prev_status) {
			priv->diff_status |= priv->current_status ^
				priv->prev_status;
			wake_up_interruptible(&priv->delta_msr_wait);
			priv->prev_status = priv->current_status;
		}
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	/* hangup, as defined in acm.c... this might be a bad place for it
	 * though */
	if (tty && !(tty->termios->c_cflag & CLOCAL) &&
			!(priv->current_status & UART_CD)) {
		dbg("%s - calling hangup", __FUNCTION__);
		tty_hangup(tty);
		goto continue_read;
	}

	/* There is one error bit... I'm assuming it is a parity error
	 * indicator as the generic firmware will set this bit to 1 if a
	 * parity error occurs.
	 * I can not find reference to any other error events. */
	spin_lock_irqsave(&priv->lock, flags);
	if (priv->current_status & CYP_ERROR) {
		spin_unlock_irqrestore(&priv->lock, flags);
		tty_flag = TTY_PARITY;
		dbg("%s - Parity Error detected", __FUNCTION__);
	} else
		spin_unlock_irqrestore(&priv->lock, flags);

	/* process read if there is data other than line status */
	if (tty && (bytes > i)) {
		for (; i < bytes ; ++i) {
			dbg("pushing byte number %d - %d - %c", i, data[i],
					data[i]);
			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
				tty_flip_buffer_push(tty);
			}
			tty_insert_flip_char(tty, data[i], tty_flag);
		}
		tty_flip_buffer_push(port->tty);
	}

	spin_lock_irqsave(&priv->lock, flags);
	/* control and status byte(s) are also counted */
	priv->bytes_in += bytes;
	spin_unlock_irqrestore(&priv->lock, flags);

continue_read:

	/* Continue trying to always read... unless the port has closed. */

	if (port->open_count > 0) {
		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
				usb_rcvintpipe(port->serial->dev,
					port->interrupt_in_endpointAddress),
				port->interrupt_in_urb->transfer_buffer,
				port->interrupt_in_urb->transfer_buffer_length,
				cypress_read_int_callback, port, interval);
		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
		if (result)
			dev_err(&urb->dev->dev, "%s - failed resubmitting "
					"read urb, error %d\n", __FUNCTION__,
					result);
	}

	return;
} /* cypress_read_int_callback */


static void cypress_write_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);
	int result;

	dbg("%s - port %d", __FUNCTION__, port->number);
	
	switch (urb->status) {
		case 0:
			/* success */
			break;
		case -ECONNRESET:
		case -ENOENT:
		case -ESHUTDOWN:
			/* this urb is terminated, clean up */
			dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
			priv->write_urb_in_use = 0;
			return;
		case -EPIPE: /* no break needed */
			usb_clear_halt(port->serial->dev, 0x02);
		default:
			/* error in the urb, so we have to resubmit it */
			dbg("%s - Overflow in write", __FUNCTION__);
			dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
			port->interrupt_out_urb->transfer_buffer_length = 1;
			port->interrupt_out_urb->dev = port->serial->dev;
			result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
			if (result)
				dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
					__FUNCTION__, result);
			else
				return;
	}
	
	priv->write_urb_in_use = 0;
	
	/* send any buffered data */
	cypress_send(port);
}


/*****************************************************************************
 * Write buffer functions - buffering code from pl2303 used
 *****************************************************************************/

/*
 * cypress_buf_alloc
 *
 * Allocate a circular buffer and all associated memory.
 */

static struct cypress_buf *cypress_buf_alloc(unsigned int size)
{

	struct cypress_buf *cb;


	if (size == 0)
		return NULL;

	cb = (struct cypress_buf *)kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
	if (cb == NULL)
		return NULL;

	cb->buf_buf = kmalloc(size, GFP_KERNEL);
	if (cb->buf_buf == NULL) {
		kfree(cb);
		return NULL;
	}

	cb->buf_size = size;
	cb->buf_get = cb->buf_put = cb->buf_buf;

	return cb;

}


/*
 * cypress_buf_free
 *
 * Free the buffer and all associated memory.
 */

static void cypress_buf_free(struct cypress_buf *cb)
{
	if (cb) {
		kfree(cb->buf_buf);
		kfree(cb);
	}
}


/*
 * cypress_buf_clear
 *
 * Clear out all data in the circular buffer.
 */

static void cypress_buf_clear(struct cypress_buf *cb)
{
	if (cb != NULL)
		cb->buf_get = cb->buf_put;
		/* equivalent to a get of all data available */
}


/*
 * cypress_buf_data_avail
 *
 * Return the number of bytes of data available in the circular
 * buffer.
 */

static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
{
	if (cb != NULL)
		return ((cb->buf_size + cb->buf_put - cb->buf_get) % cb->buf_size);
	else
		return 0;
}


/*
 * cypress_buf_space_avail
 *
 * Return the number of bytes of space available in the circular
 * buffer.
 */

static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
{
	if (cb != NULL)
		return ((cb->buf_size + cb->buf_get - cb->buf_put - 1) % cb->buf_size);
	else
		return 0;
}


/*
 * cypress_buf_put
 *
 * Copy data data from a user buffer and put it into the circular buffer.
 * Restrict to the amount of space available.
 *
 * Return the number of bytes copied.
 */

static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
	unsigned int count)
{

	unsigned int len;


	if (cb == NULL)
		return 0;

	len  = cypress_buf_space_avail(cb);
	if (count > len)
		count = len;

	if (count == 0)
		return 0;

	len = cb->buf_buf + cb->buf_size - cb->buf_put;
	if (count > len) {
		memcpy(cb->buf_put, buf, len);
		memcpy(cb->buf_buf, buf+len, count - len);
		cb->buf_put = cb->buf_buf + count - len;
	} else {
		memcpy(cb->buf_put, buf, count);
		if (count < len)
			cb->buf_put += count;
		else /* count == len */
			cb->buf_put = cb->buf_buf;
	}

	return count;

}


/*
 * cypress_buf_get
 *
 * Get data from the circular buffer and copy to the given buffer.
 * Restrict to the amount of data available.
 *
 * Return the number of bytes copied.
 */

static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
	unsigned int count)
{

	unsigned int len;


	if (cb == NULL)
		return 0;

	len = cypress_buf_data_avail(cb);
	if (count > len)
		count = len;

	if (count == 0)
		return 0;

	len = cb->buf_buf + cb->buf_size - cb->buf_get;
	if (count > len) {
		memcpy(buf, cb->buf_get, len);
		memcpy(buf+len, cb->buf_buf, count - len);
		cb->buf_get = cb->buf_buf + count - len;
	} else {
		memcpy(buf, cb->buf_get, count);
		if (count < len)
			cb->buf_get += count;
		else /* count == len */
			cb->buf_get = cb->buf_buf;
	}

	return count;

}

/*****************************************************************************
 * Module functions
 *****************************************************************************/

static int __init cypress_init(void)
{
	int retval;
	
	dbg("%s", __FUNCTION__);
	
	retval = usb_serial_register(&cypress_earthmate_device);
	if (retval)
		goto failed_em_register;
	retval = usb_serial_register(&cypress_hidcom_device);
	if (retval)
		goto failed_hidcom_register;
	retval = usb_register(&cypress_driver);
	if (retval)
		goto failed_usb_register;

	info(DRIVER_DESC " " DRIVER_VERSION);
	return 0;
failed_usb_register:
	usb_deregister(&cypress_driver);
failed_hidcom_register:
	usb_serial_deregister(&cypress_hidcom_device);
failed_em_register:
	usb_serial_deregister(&cypress_earthmate_device);

	return retval;
}


static void __exit cypress_exit (void)
{
	dbg("%s", __FUNCTION__);

	usb_deregister (&cypress_driver);
	usb_serial_deregister (&cypress_earthmate_device);
	usb_serial_deregister (&cypress_hidcom_device);
}


module_init(cypress_init);
module_exit(cypress_exit);

MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_VERSION( DRIVER_VERSION );
MODULE_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");
module_param(stats, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(stats, "Enable statistics or not");
module_param(interval, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(interval, "Overrides interrupt interval");