usbserial.c

S3C2440ARM9开发板的USB驱动程序

	dbg("%s %d", __FUNCTION__, num_ports);

	*minor = 0;
	for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
		if (serial_table[i])
			continue;

		good_spot = 1;
		for (j = 1; j <= num_ports-1; ++j)
			if (serial_table[i+j])
				good_spot = 0;
		if (good_spot == 0)
			continue;
			
		if (!(serial = kmalloc(sizeof(struct usb_serial), GFP_KERNEL))) {
			err("%s - Out of memory", __FUNCTION__);
			return NULL;
		}
		memset(serial, 0, sizeof(struct usb_serial));
		serial->magic = USB_SERIAL_MAGIC;
		serial_table[i] = serial;
		*minor = i;
		dbg("%s - minor base = %d", __FUNCTION__, *minor);
		for (i = *minor+1; (i < (*minor + num_ports)) && (i < SERIAL_TTY_MINORS); ++i)
			serial_table[i] = serial;
		return serial;
	}
	return NULL;
}

static void return_serial (struct usb_serial *serial)
{
	int i;

	dbg("%s", __FUNCTION__);

	if (serial == NULL)
		return;

	for (i = 0; i < serial->num_ports; ++i) {
		serial_table[serial->minor + i] = NULL;
	}

	return;
}

#ifdef USES_EZUSB_FUNCTIONS
/* EZ-USB Control and Status Register.  Bit 0 controls 8051 reset */
#define CPUCS_REG    0x7F92

int ezusb_writememory (struct usb_serial *serial, int address, unsigned char *data, int length, __u8 bRequest)
{
	int result;
	unsigned char *transfer_buffer;

	/* dbg("ezusb_writememory %x, %d", address, length); */
	if (!serial->dev) {
		dbg("%s - no physical device present, failing.", __FUNCTION__);
		return -ENODEV;
	}

	transfer_buffer =  kmalloc (length, GFP_KERNEL);
	if (!transfer_buffer) {
		err("%s - kmalloc(%d) failed.", __FUNCTION__, length);
		return -ENOMEM;
	}
	memcpy (transfer_buffer, data, length);
	result = usb_control_msg (serial->dev, usb_sndctrlpipe(serial->dev, 0), bRequest, 0x40, address, 0, transfer_buffer, length, 3*HZ);
	kfree (transfer_buffer);
	return result;
}

int ezusb_set_reset (struct usb_serial *serial, unsigned char reset_bit)
{
	int	response;
	dbg("%s - %d", __FUNCTION__, reset_bit);
	response = ezusb_writememory (serial, CPUCS_REG, &reset_bit, 1, 0xa0);
	if (response < 0) {
		err("%s- %d failed", __FUNCTION__, reset_bit);
	}
	return response;
}

#endif	/* USES_EZUSB_FUNCTIONS */

/*****************************************************************************
 * Driver tty interface functions
 *****************************************************************************/
static int serial_open (struct tty_struct *tty, struct file * filp)
{
	struct usb_serial *serial;
	struct usb_serial_port *port;
	unsigned int portNumber;
	int retval = 0;
	
	dbg("%s", __FUNCTION__);

	/* initialize the pointer incase something fails */
	tty->driver_data = NULL;

	/* get the serial object associated with this tty pointer */
	serial = get_serial_by_minor (MINOR(tty->device));

	if (serial_paranoia_check (serial, __FUNCTION__))
		return -ENODEV;

	/* set up our port structure making the tty driver remember our port object, and us it */
	portNumber = MINOR(tty->device) - serial->minor;
	port = &serial->port[portNumber];
	tty->driver_data = port;

	down (&port->sem);
	port->tty = tty;
	 
	/* lock this module before we call it */
	if (serial->type->owner)
		__MOD_INC_USE_COUNT(serial->type->owner);

	++port->open_count;
	if (port->open_count == 1) {
		/* only call the device specific open if this 
		 * is the first time the port is opened */
		if (serial->type->open)
			retval = serial->type->open(port, filp);
		else
			retval = generic_open(port, filp);
	}

	if (retval) {
		port->open_count = 0;
		if (serial->type->owner)
			__MOD_DEC_USE_COUNT(serial->type->owner);
	}

	up (&port->sem);
	return retval;
}

static void __serial_close(struct usb_serial_port *port, struct file *filp)
{
	if (!port->open_count) {
		dbg ("%s - port not opened", __FUNCTION__);
		return;
	}

	--port->open_count;
	if (port->open_count <= 0) {
		/* only call the device specific close if this 
		 * port is being closed by the last owner */
		if (port->serial->type->close)
			port->serial->type->close(port, filp);
		else
			generic_close(port, filp);
		port->open_count = 0;
	}

	if (port->serial->type->owner)
		__MOD_DEC_USE_COUNT(port->serial->type->owner);
}

static void serial_close(struct tty_struct *tty, struct file * filp)
{
	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);

	if (!serial)
		return;

	down (&port->sem);

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

	/* if disconnect beat us to the punch here, there's nothing to do */
	if (tty->driver_data) {
		__serial_close(port, filp);
	}

	up (&port->sem);
}

static int serial_write (struct tty_struct * tty, int from_user, const unsigned char *buf, int count)
{
	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
	int retval = -EINVAL;

	if (!serial)
		return -ENODEV;

	down (&port->sem);

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

	if (!port->open_count) {
		dbg("%s - port not opened", __FUNCTION__);
		goto exit;
	}

	/* pass on to the driver specific version of this function if it is available */
	if (serial->type->write)
		retval = serial->type->write(port, from_user, buf, count);
	else
		retval = generic_write(port, from_user, buf, count);

exit:
	up (&port->sem);
	return retval;
}

static int serial_write_room (struct tty_struct *tty) 
{
	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
	int retval = -EINVAL;

	if (!serial)
		return -ENODEV;

	down (&port->sem);

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

	if (!port->open_count) {
		dbg("%s - port not open", __FUNCTION__);
		goto exit;
	}

	/* pass on to the driver specific version of this function if it is available */
	if (serial->type->write_room)
		retval = serial->type->write_room(port);
	else
		retval = generic_write_room(port);

exit:
	up (&port->sem);
	return retval;
}

static int serial_chars_in_buffer (struct tty_struct *tty) 
{
	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
	int retval = -EINVAL;

	if (!serial)
		return -ENODEV;

	down (&port->sem);

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

	if (!port->open_count) {
		dbg("%s - port not open", __FUNCTION__);
		goto exit;
	}

	/* pass on to the driver specific version of this function if it is available */
	if (serial->type->chars_in_buffer)
		retval = serial->type->chars_in_buffer(port);
	else
		retval = generic_chars_in_buffer(port);

exit:
	up (&port->sem);
	return retval;
}

static void serial_throttle (struct tty_struct * tty)
{
	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);

	if (!serial)
		return;

	down (&port->sem);

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

	if (!port->open_count) {
		dbg ("%s - port not open", __FUNCTION__);
		goto exit;
	}

	/* pass on to the driver specific version of this function */
	if (serial->type->throttle)
		serial->type->throttle(port);

exit:
	up (&port->sem);
}

static void serial_unthrottle (struct tty_struct * tty)
{
	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);

	if (!serial)
		return;

	down (&port->sem);

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

	if (!port->open_count) {
		dbg("%s - port not open", __FUNCTION__);
		goto exit;
	}

	/* pass on to the driver specific version of this function */
	if (serial->type->unthrottle)
		serial->type->unthrottle(port);

exit:
	up (&port->sem);
}

static int serial_ioctl (struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg)
{
	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
	int retval = -ENODEV;

	if (!serial)
		return -ENODEV;

	down (&port->sem);

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

	if (!port->open_count) {
		dbg ("%s - port not open", __FUNCTION__);
		goto exit;
	}

	/* pass on to the driver specific version of this function if it is available */
	if (serial->type->ioctl)
		retval = serial->type->ioctl(port, file, cmd, arg);
	else
		retval = -ENOIOCTLCMD;

exit:
	up (&port->sem);
	return retval;
}

static void serial_set_termios (struct tty_struct *tty, struct termios * old)
{
	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);

	if (!serial)
		return;

	down (&port->sem);

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

	if (!port->open_count) {
		dbg("%s - port not open", __FUNCTION__);
		goto exit;
	}

	/* pass on to the driver specific version of this function if it is available */
	if (serial->type->set_termios)
		serial->type->set_termios(port, old);

exit:
	up (&port->sem);
}

static void serial_break (struct tty_struct *tty, int break_state)
{
	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);

	if (!serial)
		return;

	down (&port->sem);

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

	if (!port->open_count) {
		dbg("%s - port not open", __FUNCTION__);
		goto exit;
	}

	/* pass on to the driver specific version of this function if it is available */
	if (serial->type->break_ctl)
		serial->type->break_ctl(port, break_state);

exit:
	up (&port->sem);
}

static void serial_shutdown (struct usb_serial *serial)
{
	dbg ("%s", __FUNCTION__);

	if (serial->type->shutdown)
		serial->type->shutdown(serial);