mos7720.c

linux 内核源代码

	/* Freeing Write URBs */
	for (j = 0; j < NUM_URBS; ++j) {
		if (mos7720_port->write_urb_pool[j]) {
			kfree(mos7720_port->write_urb_pool[j]->transfer_buffer);
			usb_free_urb(mos7720_port->write_urb_pool[j]);
		}
	}

	/* While closing port, shutdown all bulk read, write  *
	 * and interrupt read if they exists                  */
	if (serial->dev) {
		dbg("Shutdown bulk write");
		usb_kill_urb(port->write_urb);
		dbg("Shutdown bulk read");
		usb_kill_urb(port->read_urb);
	}

	data = 0x00;
	send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
		     0x04, &data);

	data = 0x00;
	send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
		     0x01, &data);

	mos7720_port->open = 0;

	dbg("Leaving %s", __FUNCTION__);
}

static void mos7720_break(struct usb_serial_port *port, int break_state)
{
        unsigned char data;
	struct usb_serial *serial;
	struct moschip_port *mos7720_port;

	dbg("Entering %s", __FUNCTION__);

	serial = port->serial;

	mos7720_port = usb_get_serial_port_data(port);
	if (mos7720_port == NULL)
		return;

	if (break_state == -1)
		data = mos7720_port->shadowLCR | UART_LCR_SBC;
	else
		data = mos7720_port->shadowLCR & ~UART_LCR_SBC;

	mos7720_port->shadowLCR  = data;
	send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
		     0x03, &data);

	return;
}

/*
 * mos7720_write_room
 *	this function is called by the tty driver when it wants to know how many
 *	bytes of data we can accept for a specific port.
 *	If successful, we return the amount of room that we have for this port
 *	Otherwise we return a negative error number.
 */
static int mos7720_write_room(struct usb_serial_port *port)
{
	struct moschip_port *mos7720_port;
	int room = 0;
	int i;

	dbg("%s:entering ...........", __FUNCTION__);

	mos7720_port = usb_get_serial_port_data(port);
	if (mos7720_port == NULL) {
		dbg("%s:leaving ...........", __FUNCTION__);
		return -ENODEV;
	}

	for (i = 0; i < NUM_URBS; ++i) {
		if (mos7720_port->write_urb_pool[i] && mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
			room += URB_TRANSFER_BUFFER_SIZE;
	}

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

static int mos7720_write(struct usb_serial_port *port,
			 const unsigned char *data, int count)
{
	int status;
	int i;
	int bytes_sent = 0;
	int transfer_size;

	struct moschip_port *mos7720_port;
	struct usb_serial *serial;
	struct urb    *urb;
	const unsigned char *current_position = data;

	dbg("%s:entering ...........", __FUNCTION__);

	serial = port->serial;

	mos7720_port = usb_get_serial_port_data(port);
	if (mos7720_port == NULL) {
		dbg("mos7720_port is NULL");
		return -ENODEV;
	}

	/* try to find a free urb in the list */
	urb = NULL;

	for (i = 0; i < NUM_URBS; ++i) {
		if (mos7720_port->write_urb_pool[i] && mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
			urb = mos7720_port->write_urb_pool[i];
			dbg("URB:%d",i);
			break;
		}
	}

	if (urb == NULL) {
		dbg("%s - no more free urbs", __FUNCTION__);
		goto exit;
	}

	if (urb->transfer_buffer == NULL) {
		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
					       GFP_KERNEL);
		if (urb->transfer_buffer == NULL) {
			err("%s no more kernel memory...", __FUNCTION__);
			goto exit;
		}
	}
	transfer_size = min (count, URB_TRANSFER_BUFFER_SIZE);

	memcpy(urb->transfer_buffer, current_position, transfer_size);
	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, transfer_size,
			      urb->transfer_buffer);

	/* fill urb with data and submit  */
	usb_fill_bulk_urb(urb, serial->dev,
			  usb_sndbulkpipe(serial->dev,
			  		  port->bulk_out_endpointAddress),
			  urb->transfer_buffer, transfer_size,
			  mos7720_bulk_out_data_callback, mos7720_port);

	/* send it down the pipe */
	status = usb_submit_urb(urb,GFP_ATOMIC);
	if (status) {
		err("%s - usb_submit_urb(write bulk) failed with status = %d",
		    __FUNCTION__, status);
		bytes_sent = status;
		goto exit;
	}
	bytes_sent = transfer_size;

exit:
	return bytes_sent;
}

static void mos7720_throttle(struct usb_serial_port *port)
{
	struct moschip_port *mos7720_port;
	struct tty_struct *tty;
	int status;

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

	mos7720_port = usb_get_serial_port_data(port);

	if (mos7720_port == NULL)
		return;

	if (!mos7720_port->open) {
		dbg("port not opened");
		return;
	}

	dbg("%s: Entering ..........", __FUNCTION__);

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

	/* if we are implementing XON/XOFF, send the stop character */
	if (I_IXOFF(tty)) {
		unsigned char stop_char = STOP_CHAR(tty);
		status = mos7720_write(port, &stop_char, 1);
		if (status <= 0)
			return;
	}

	/* if we are implementing RTS/CTS, toggle that line */
	if (tty->termios->c_cflag & CRTSCTS) {
		mos7720_port->shadowMCR &= ~UART_MCR_RTS;
		status = send_mos_cmd(port->serial, MOS_WRITE,
				      port->number - port->serial->minor,
				      UART_MCR, &mos7720_port->shadowMCR);
		if (status != 0)
			return;
	}
}

static void mos7720_unthrottle(struct usb_serial_port *port)
{
	struct tty_struct *tty;
	int status;
	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);

	if (mos7720_port == NULL)
		return;

	if (!mos7720_port->open) {
		dbg("%s - port not opened", __FUNCTION__);
		return;
	}

	dbg("%s: Entering ..........", __FUNCTION__);

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

	/* if we are implementing XON/XOFF, send the start character */
	if (I_IXOFF(tty)) {
		unsigned char start_char = START_CHAR(tty);
		status = mos7720_write(port, &start_char, 1);
		if (status <= 0)
			return;
	}

	/* if we are implementing RTS/CTS, toggle that line */
	if (tty->termios->c_cflag & CRTSCTS) {
		mos7720_port->shadowMCR |= UART_MCR_RTS;
		status = send_mos_cmd(port->serial, MOS_WRITE,
				      port->number - port->serial->minor,
				      UART_MCR, &mos7720_port->shadowMCR);
		if (status != 0)
			return;
	}
}

static int set_higher_rates(struct moschip_port *mos7720_port,
			    unsigned int baud)
{
	unsigned char data;
	struct usb_serial_port *port;
	struct usb_serial *serial;
	int port_number;

	if (mos7720_port == NULL)
		return -EINVAL;

	port = mos7720_port->port;
	serial = port->serial;

        /***********************************************
         *      Init Sequence for higher rates
         ***********************************************/
	dbg("Sending Setting Commands ..........");
	port_number = port->number - port->serial->minor;

	data = 0x000;
	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
	data = 0x000;
	send_mos_cmd(serial, MOS_WRITE, port_number, 0x02, &data);
	data = 0x0CF;
	send_mos_cmd(serial, MOS_WRITE, port->number, 0x02, &data);
	data = 0x00b;
        mos7720_port->shadowMCR  = data;
	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
	data = 0x00b;
	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);

	data = 0x000;
	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
	data = 0x000;
	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);


        /***********************************************
         *              Set for higher rates           *
         ***********************************************/

	data = baud * 0x10;
	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, port_number + 1,&data);

	data = 0x003;
	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
	data = 0x003;
	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);

	data = 0x02b;
        mos7720_port->shadowMCR  = data;
	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
	data = 0x02b;
	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);

        /***********************************************
         *              Set DLL/DLM
         ***********************************************/

	data = mos7720_port->shadowLCR | UART_LCR_DLAB;
        mos7720_port->shadowLCR  = data;
	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);

	data =  0x001; /* DLL */
        send_mos_cmd(serial, MOS_WRITE, port_number, 0x00, &data);
	data =  0x000; /* DLM */
        send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);

	data = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
        mos7720_port->shadowLCR  = data;
	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);

	return 0;
}

/* baud rate information */
struct divisor_table_entry
{
	__u32  baudrate;
	__u16  divisor;
};

/* Define table of divisors for moschip 7720 hardware	   *
 * These assume a 3.6864MHz crystal, the standard /16, and *
 * MCR.7 = 0.						   */
static struct divisor_table_entry divisor_table[] = {
	{   50,		2304},
	{   110,	1047},	/* 2094.545455 => 230450   => .0217 % over */
	{   134,	857},	/* 1713.011152 => 230398.5 => .00065% under */
	{   150,	768},
	{   300,	384},
	{   600,	192},
	{   1200,	96},
	{   1800,	64},
	{   2400,	48},
	{   4800,	24},
	{   7200,	16},
	{   9600,	12},
	{   19200,	6},
	{   38400,	3},
	{   57600,	2},
	{   115200,	1},
};

/*****************************************************************************
 * calc_baud_rate_divisor
 *	this function calculates the proper baud rate divisor for the specified
 *	baud rate.
 *****************************************************************************/
static int calc_baud_rate_divisor(int baudrate, int *divisor)
{
	int i;
	__u16 custom;
	__u16 round1;
	__u16 round;


	dbg("%s - %d", __FUNCTION__, baudrate);

	for (i = 0; i < ARRAY_SIZE(divisor_table); i++) {
		if (divisor_table[i].baudrate == baudrate) {
			*divisor = divisor_table[i].divisor;
			return 0;
		}
	}

        /* After trying for all the standard baud rates    *
         * Try calculating the divisor for this baud rate  */
	if (baudrate > 75 &&  baudrate < 230400) {
		/* get the divisor */
		custom = (__u16)(230400L  / baudrate);

		/* Check for round off */
		round1 = (__u16)(2304000L / baudrate);
		round = (__u16)(round1 - (custom * 10));
		if (round > 4)
			custom++;
		*divisor = custom;

		dbg("Baud %d = %d",baudrate, custom);
		return 0;
	}

	dbg("Baud calculation Failed...");
	return -EINVAL;
}

/*
 * send_cmd_write_baud_rate
 *	this function sends the proper command to change the baud rate of the
 *	specified port.
 */
static int send_cmd_write_baud_rate(struct moschip_port *mos7720_port,
				    int baudrate)
{
	struct usb_serial_port *port;
	struct usb_serial *serial;
	int divisor;
	int status;
	unsigned char data;
	unsigned char number;

	if (mos7720_port == NULL)
		return -1;

	port = mos7720_port->port;
	serial = port->serial;

	dbg("%s: Entering ..........", __FUNCTION__);

	number = port->number - port->serial->minor;
	dbg("%s - port = %d, baud = %d", __FUNCTION__, port->number, baudrate);

        /* Calculate the Divisor */
	status = calc_baud_rate_divisor(baudrate, &divisor);
	if (status) {
		err("%s - bad baud rate", __FUNCTION__);
		return status;
	}

        /* Enable access to divisor latch */
        data = mos7720_port->shadowLCR | UART_LCR_DLAB;
        mos7720_port->shadowLCR  = data;
        send_mos_cmd(serial, MOS_WRITE, number, UART_LCR, &data);

	/* Write the divisor */
	data = ((unsigned char)(divisor & 0xff));
        send_mos_cmd(serial, MOS_WRITE, number, 0x00, &data);

	data = ((unsigned char)((divisor & 0xff00) >> 8));
        send_mos_cmd(serial, MOS_WRITE, number, 0x01, &data);

        /* Disable access to divisor latch */
        data = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
        mos7720_port->shadowLCR = data;
        send_mos_cmd(serial, MOS_WRITE, number, 0x03, &data);

	return status;
}

/*
 * change_port_settings
 *	This routine is called to set the UART on the device to match
 *      the specified new settings.
 */
static void change_port_settings(struct moschip_port *mos7720_port,
				 struct ktermios *old_termios)
{
	struct usb_serial_port *port;
	struct usb_serial *serial;
	struct tty_struct *tty;
	int baud;
	unsigned cflag;
	unsigned iflag;
	__u8 mask = 0xff;
	__u8 lData;
	__u8 lParity;
	__u8 lStop;
	int status;
	int port_number;
	char data;

	if (mos7720_port == NULL)
		return ;

	port = mos7720_port->port;
	serial = port->serial;
	port_number = port->number - port->serial->minor;

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

	if (!mos7720_port->open) {
		dbg("%s - port not opened", __FUNCTION__);
		return;
	}

	tty = mos7720_port->port->tty;

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

	dbg("%s: Entering ..........", __FUNCTION__);

	lData = UART_LCR_WLEN8;
	lStop = 0x00;	/* 1 stop bit */
	lParity = 0x00;	/* No parity */

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

	/* Change the number of bits */
	switch (cflag & CSIZE) {
	case CS5:
		lData = UART_LCR_WLEN5;
		mask = 0x1f;
		break;

	case CS6:
		lData = UART_LCR_WLEN6;
		mask = 0x3f;
		break;

	case CS7:
		lData = UART_LCR_WLEN7;
		mask = 0x7f;
		break;
	default:
	case CS8:
		lData = UART_LCR_WLEN8;
		break;
	}

	/* Change the Parity bit */
	if (cflag & PARENB) {
		if (cflag & PARODD) {
			lParity = UART_LCR_PARITY;
			dbg("%s - parity = odd", __FUNCTION__);
		} else {
			lParity = (UART_LCR_EPAR | UART_LCR_PARITY);
			dbg("%s - parity = even", __FUNCTION__);
		}

	} else {
		dbg("%s - parity = none", __FUNCTION__);
	}

	if (cflag & CMSPAR)
		lParity = lParity | 0x20;

	/* Change the Stop bit */
	if (cflag & CSTOPB) {
		lStop = UART_LCR_STOP;
		dbg("%s - stop bits = 2", __FUNCTION__);
	} else {
		lStop = 0x00;
		dbg("%s - stop bits = 1", __FUNCTION__);
	}

#define LCR_BITS_MASK		0x03	/* Mask for bits/char field */
#define LCR_STOP_MASK		0x04	/* Mask for stop bits field */
#define LCR_PAR_MASK		0x38	/* Mask for parity field */

	/* Update the LCR with the correct value */
	mos7720_port->shadowLCR &= ~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
	mos7720_port->shadowLCR |= (lData | lParity | lStop);


	/* Disable Interrupts */