serial_44b0.c

serial port driver in linux

	info->IER = 0;
	serial_outp(info, UART_IER, 0x00);	// disable all intrs
*/
	disable_uart_rx_interrupt(info->line);
	disable_uart_tx_interrupt(info->line);
	if(info->line==0||info->line==1)
		(void)uart_in(info, UART_RX);    // read data port to reset things
	/*else                                                                         */
		/*(void)uart_in(info, EX_UART_RX);    // read data port to reset things*/

	
	if (info->tty)
		set_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags &= ~ASYNC_INITIALIZED;
	restore_flags(flags);
}

#if (LINUX_VERSION_CODE < 131394) /* Linux 2.1.66 */
static int baud_table[] = {
	0, 50, 75, 110, 134, 150, 200, 300,
	600, 1200, 1800, 2400, 4800, 9600, 19200,
	38400, 57600, 115200, 230400, 460800, 0 };
#endif

/*
 * This routine is called to set the UART divisor registers to match
 * the specified baud rate for a serial port.
 */
static void change_speed(struct async_struct *info,
			 struct termios *old_termios)
{
	int	quot = 0, baud_base, baud;
//	unsigned cflag, cval, fcr = 0;
	unsigned cflag, cval;
	int	bits;
	unsigned long	flags;

	if (!info->tty || !info->tty->termios)
		return;
	cflag = info->tty->termios->c_cflag;
	if (!CONFIGURED_SERIAL_PORT(info))
		return;

	// byte size and parity
	switch (cflag & CSIZE) {
	      case CS5: cval = 0x00; bits = 7; break;
	      case CS6: cval = 0x01; bits = 8; break;
	      case CS7: cval = 0x02; bits = 9; break;
	      case CS8: cval = 0x03; bits = 10; break;
	      // Never happens, but GCC is too dumb to figure it out
	      default:  cval = 0x00; bits = 7; break;
	      }
	if (cflag & CSTOPB) {
		cval |= 0x04;
		bits++;
	}
	if (cflag & PARENB) {
		bits++;
	}
	if (cflag & PARODD)
		cval |= UART_LCR_OPAR;
	else if (cflag & PARENB)
		cval |= UART_LCR_EPAR;
	else
		cval |= UART_LCR_NPAR;

#ifdef CONFIG_SERIAL_SAMSUNG_IRDA
	if (info->line == 1){
		cval |= UART_LCR_IRDA;
	}
#endif

	// Determine divisor based on baud rate
	baud = tty_get_baud_rate(info->tty);
	if (!baud)
		baud = 9600;	// B0 transition handled in rs_set_termios

	baud_base = info->state->baud_base;

	quot = 1;	//tricky

	// If the quotient is zero refuse the change
	if (!quot && old_termios) {
		info->tty->termios->c_cflag &= ~CBAUD;
		info->tty->termios->c_cflag |= (old_termios->c_cflag & CBAUD);
		baud = tty_get_baud_rate(info->tty);
		if (!baud)
			baud = 9600;
	}
	// As a last resort, if the quotient is zero, default to 9600 bps
	if (!quot)
		quot = baud_base / 9600;
	//
	// Work around a bug in the Oxford Semiconductor 952 rev B
	// chip which causes it to seriously miscalculate baud rates
	// when DLL is 0.
	//
	info->quot = quot;
	info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
	info->timeout += HZ/50;		// Add .02 seconds of slop


	//
	// Set up parity check flag
	//
#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))

	info->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
	if (I_INPCK(info->tty))
		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
	if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
		info->read_status_mask |= UART_LSR_BI;
	
	//
	// Characters to ignore
	//
	info->ignore_status_mask = 0;
	if (I_IGNPAR(info->tty))
		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
	if (I_IGNBRK(info->tty)) {
		info->ignore_status_mask |= UART_LSR_BI;
		//
		// If we're ignore parity and break indicators, ignore 
		// overruns too.  (For real raw support).
		//
		if (I_IGNPAR(info->tty))
			info->ignore_status_mask |= UART_LSR_OE;
	}
	save_flags(flags); cli();
	info->LCR = cval;				// Save LCR
	if(info->line==0||info->line==1)
	{
		serial_outp(info, UART_BDR, baudrate_div(baud));
		serial_outp(info, UART_LCR, cval);
	}
	/*else                                                             */
	/*{                                                                */
		/*serial_outp(info, EX_UART_LCR, 0x80);	//set line ctrol   */
		/*serial_outp(info, EX_UART_BDR, 115200%baud);             */
		/*serial_outp(info, EX_UART_BDR+1, 115200/baud);           */
		/*serial_outp(info, EX_UART_LCR, cval);	//re set line ctrol*/
	/*}                                                                */
	restore_flags(flags);
}

static void rs_put_char(struct tty_struct *tty, unsigned char ch)
{
	struct async_struct *info = (struct async_struct *)tty->driver_data;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->device, "rs_put_char"))
		return;

	if (!tty || !info->xmit.buf)
		return;

	save_flags(flags); cli();
	if (CIRC_SPACE(info->xmit.head,
		       info->xmit.tail,
		       SERIAL_XMIT_SIZE) == 0) {
		restore_flags(flags);
		return;
	}
#ifdef UARTPOLLING
	wait_for_xmitr(info);
	/*	Send the character out. */
	if(info->line==0||info->line==1)
		uart_out(info, UART_TX, ch);
	/*else                                   */
		/*uart_out(info, EX_UART_TX, ch);*/
	    
#else
	info->xmit.buf[info->xmit.head] = ch;
	info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
#endif
	restore_flags(flags);
}

static void rs_flush_chars(struct tty_struct *tty)
{
	struct async_struct *info = (struct async_struct *)tty->driver_data;
	unsigned long flags;
				
	if (serial_paranoia_check(info, tty->device, "rs_flush_chars"))
		return;

	if (info->xmit.head == info->xmit.tail
	    || tty->stopped
	    || tty->hw_stopped
	    || !info->xmit.buf)
		return;

	save_flags(flags); cli();

	enable_uart_tx_interrupt(info->line);
	restore_flags(flags);
}

static int rs_write(struct tty_struct * tty, int from_user,
		    const unsigned char *buf, int count)
{
	int	c, ret = 0;
	struct async_struct *info = (struct async_struct *)tty->driver_data;
	unsigned long flags;
				
	if (serial_paranoia_check(info, tty->device, "rs_write"))
		return 0;

	if (!tty || !info->xmit.buf || !tmp_buf)
		return 0;

	save_flags(flags);
	if (from_user) {
		down(&tmp_buf_sem);
		while (1) {
			int c1;
			c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
			if (count < c)
				c = count;
			if (c <= 0)
				break;

			c -= copy_from_user(tmp_buf, buf, c);
			if (!c) {
				if (!ret)
					ret = -EFAULT;
				break;
			}
			cli();
			c1 = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
			if (c1 < c)
				c = c1;
			memcpy(info->xmit.buf + info->xmit.head, tmp_buf, c);
			info->xmit.head = ((info->xmit.head + c) & (SERIAL_XMIT_SIZE-1));
			restore_flags(flags);
			buf += c;
			count -= c;
			ret += c;
		}
		up(&tmp_buf_sem);
	} else {
		cli();
		while (1) {
			c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
			if (count < c)
				c = count;
			if (c <= 0) {
				break;
			}
			memcpy(info->xmit.buf + info->xmit.head, buf, c);
			info->xmit.head = ((info->xmit.head + c) & (SERIAL_XMIT_SIZE-1));
			buf += c;
			count -= c;
			ret += c;
		}
		restore_flags(flags);
	}
	if (info->xmit.head != info->xmit.tail && !tty->stopped && !tty->hw_stopped) 
	{
#ifdef UARTPOLLING
		cli();
        count = ret;
        do {
        	wait_for_xmitr(info);
        	/*	Send the character out. */
		if(info->line==0||info->line==1)
			uart_out(info, UART_TX, info->xmit.buf[info->xmit.tail]);
		/*else                                                                */
			/*uart_out(info, EX_UART_TX, info->xmit.buf[info->xmit.tail]);*/
		    
        	info->xmit.tail = (info->xmit.tail + 1) & (SERIAL_XMIT_SIZE-1);
        	info->state->icount.tx++;
        	if (info->xmit.head == info->xmit.tail)
        		break;
        } while (--count > 0);
    	restore_flags(flags);
#else
		enable_uart_tx_interrupt(info->line);
#endif
	}
	return ret;
}

static int rs_write_room(struct tty_struct *tty)
{
	struct async_struct *info = (struct async_struct *)tty->driver_data;

	if (serial_paranoia_check(info, tty->device, "rs_write_room"))
		return 0;
	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}

static int rs_chars_in_buffer(struct tty_struct *tty)
{
	struct async_struct *info = (struct async_struct *)tty->driver_data;
				
	if (serial_paranoia_check(info, tty->device, "rs_chars_in_buffer"))
		return 0;
	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}

static void rs_flush_buffer(struct tty_struct *tty)
{
	struct async_struct *info = (struct async_struct *)tty->driver_data;
	unsigned long flags;
	
	if (serial_paranoia_check(info, tty->device, "rs_flush_buffer"))
		return;
	save_flags(flags); cli();
	info->xmit.head = info->xmit.tail = 0;
	restore_flags(flags);
	wake_up_interruptible(&tty->write_wait);
#ifdef SERIAL_HAVE_POLL_WAIT
	wake_up_interruptible(&tty->poll_wait);
#endif
	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
	    tty->ldisc.write_wakeup)
		(tty->ldisc.write_wakeup)(tty);
}

/*
 * This function is used to send a high-priority XON/XOFF character to
 * the device
 */
static void rs_send_xchar(struct tty_struct *tty, char ch)
{
	struct async_struct *info = (struct async_struct *)tty->driver_data;

	if (serial_paranoia_check(info, tty->device, "rs_send_char"))
		return;

	info->x_char = ch;
	if (ch) {
		// Make sure transmit interrupts are on
		enable_uart_tx_interrupt(info->line);
	}
}

/*
 * ------------------------------------------------------------
 * rs_throttle()
 * 
 * This routine is called by the upper-layer tty layer to signal that
 * incoming characters should be throttled.
 * ------------------------------------------------------------
 */
static void rs_throttle(struct tty_struct * tty)
{
	struct async_struct *info = (struct async_struct *)tty->driver_data;
	unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
	char	buf[64];
	
	printk("throttle %s: %d....\n", tty_name(tty, buf),
	       tty->ldisc.chars_in_buffer(tty));
#endif

	if (serial_paranoia_check(info, tty->device, "rs_throttle"))
		return;
	
	if (I_IXOFF(tty))
		rs_send_xchar(tty, STOP_CHAR(tty));
/*
	if (tty->termios->c_cflag & CRTSCTS)
		info->MCR &= ~UART_MCR_RTS;
*/
	save_flags(flags); cli();

	restore_flags(flags);
}

static void rs_unthrottle(struct tty_struct * tty)
{
	struct async_struct *info = (struct async_struct *)tty->driver_data;
	unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
	char	buf[64];
	
	printk("unthrottle %s: %d....\n", tty_name(tty, buf),
	       tty->ldisc.chars_in_buffer(tty));
#endif

	if (serial_paranoia_check(info, tty->device, "rs_unthrottle"))
		return;
	
	if (I_IXOFF(tty)) {
		if (info->x_char)
			info->x_char = 0;
		else
			rs_send_xchar(tty, START_CHAR(tty));
	}

	save_flags(flags); cli();

	restore_flags(flags);
}

/*
 * ------------------------------------------------------------
 * rs_ioctl() and friends
 * ------------------------------------------------------------
 */
static int get_serial_info(struct async_struct * info,
			   struct serial_struct * retinfo)
{
	struct serial_struct tmp;
	struct serial_state *state = info->state;
   
	if (!retinfo)
		return -EFAULT;
	memset(&tmp, 0, sizeof(tmp));
	tmp.type = state->type;
	tmp.line = state->line;
	tmp.port = state->port;
	if (HIGH_BITS_OFFSET)
		tmp.port_high = state->port >> HIGH_BITS_OFFSET;
	else
		tmp.port_high = 0;
	tmp.irq = state->irq;
	tmp.flags = state->flags;
	tmp.xmit_fifo_size = state->xmit_fifo_size;
	tmp.baud_base = state->baud_base;
	tmp.close_delay = state->close_delay;
	tmp.closing_wait = state->closing_wait;
	tmp.custom_divisor = state->custom_divisor;
	tmp.hub6 = state->hub6;
	tmp.io_type = state->io_type;
	if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
		return -EFAULT;
	return 0;
}

static int set_serial_info(struct async_struct * info,
			   struct serial_struct * new_info)
{
	struct serial_struct new_serial;
 	struct serial_state old_state, *state;
	unsigned int		i,change_irq,change_port;
	int 			retval = 0;
	unsigned long		new_port;

	if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
		return -EFAULT;
	state = info->state;
	old_state = *state;