68360serial.c

linux 内核源代码

	if (!tty) 
		return 0;

	bdp = info->tx_cur;

	while (1) {
		c = min(count, TX_BUF_SIZE);

		if (c <= 0)
			break;

		if (bdp->status & BD_SC_READY) {
			info->flags |= TX_WAKEUP;
			break;
		}

		/* memcpy(__va(bdp->buf), buf, c); */
		memcpy((void *)bdp->buf, buf, c);

		bdp->length = c;
		bdp->status |= BD_SC_READY;

		buf += c;
		count -= c;
		ret += c;

		/* Get next BD.
		*/
		if (bdp->status & BD_SC_WRAP)
			bdp = info->tx_bd_base;
		else
			bdp++;
		info->tx_cur = (QUICC_BD *)bdp;
	}
	return ret;
}

static int rs_360_write_room(struct tty_struct *tty)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;
	int	ret;

	if (serial_paranoia_check(info, tty->name, "rs_write_room"))
		return 0;

	if ((info->tx_cur->status & BD_SC_READY) == 0) {
		info->flags &= ~TX_WAKEUP;
		ret = TX_BUF_SIZE;
	}
	else {
		info->flags |= TX_WAKEUP;
		ret = 0;
	}
	return ret;
}

/* I could track this with transmit counters....maybe later.
*/
static int rs_360_chars_in_buffer(struct tty_struct *tty)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;
				
	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
		return 0;
	return 0;
}

static void rs_360_flush_buffer(struct tty_struct *tty)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;
				
	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
		return;

	/* There is nothing to "flush", whatever we gave the CPM
	 * is on its way out.
	 */
	tty_wakeup(tty);
	info->flags &= ~TX_WAKEUP;
}

/*
 * This function is used to send a high-priority XON/XOFF character to
 * the device
 */
static void rs_360_send_xchar(struct tty_struct *tty, char ch)
{
	volatile QUICC_BD	*bdp;

	ser_info_t *info = (ser_info_t *)tty->driver_data;

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

	bdp = info->tx_cur;
	while (bdp->status & BD_SC_READY);

	/* *((char *)__va(bdp->buf)) = ch; */
	*((char *)bdp->buf) = ch;
	bdp->length = 1;
	bdp->status |= BD_SC_READY;

	/* Get next BD.
	*/
	if (bdp->status & BD_SC_WRAP)
		bdp = info->tx_bd_base;
	else
		bdp++;

	info->tx_cur = (QUICC_BD *)bdp;
}

/*
 * ------------------------------------------------------------
 * rs_throttle()
 * 
 * This routine is called by the upper-layer tty layer to signal that
 * incoming characters should be throttled.
 * ------------------------------------------------------------
 */
static void rs_360_throttle(struct tty_struct * tty)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;
#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->name, "rs_throttle"))
		return;
	
	if (I_IXOFF(tty))
		rs_360_send_xchar(tty, STOP_CHAR(tty));

#ifdef modem_control
	if (tty->termios->c_cflag & CRTSCTS)
		info->MCR &= ~UART_MCR_RTS;

	local_irq_disable();
	serial_out(info, UART_MCR, info->MCR);
	local_irq_enable();
#endif
}

static void rs_360_unthrottle(struct tty_struct * tty)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;
#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->name, "rs_unthrottle"))
		return;
	
	if (I_IXOFF(tty)) {
		if (info->x_char)
			info->x_char = 0;
		else
			rs_360_send_xchar(tty, START_CHAR(tty));
	}
#ifdef modem_control
	if (tty->termios->c_cflag & CRTSCTS)
		info->MCR |= UART_MCR_RTS;
	local_irq_disable();
	serial_out(info, UART_MCR, info->MCR);
	local_irq_enable();
#endif
}

/*
 * ------------------------------------------------------------
 * rs_ioctl() and friends
 * ------------------------------------------------------------
 */

#ifdef maybe
/*
 * get_lsr_info - get line status register info
 *
 * Purpose: Let user call ioctl() to get info when the UART physically
 * 	    is emptied.  On bus types like RS485, the transmitter must
 * 	    release the bus after transmitting. This must be done when
 * 	    the transmit shift register is empty, not be done when the
 * 	    transmit holding register is empty.  This functionality
 * 	    allows an RS485 driver to be written in user space. 
 */
static int get_lsr_info(struct async_struct * info, unsigned int *value)
{
	unsigned char status;
	unsigned int result;

	local_irq_disable();
	status = serial_in(info, UART_LSR);
	local_irq_enable();
	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
	return put_user(result,value);
}
#endif

static int rs_360_tiocmget(struct tty_struct *tty, struct file *file)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;
	unsigned int result = 0;
#ifdef modem_control
	unsigned char control, status;

	if (serial_paranoia_check(info, tty->name, __FUNCTION__))
		return -ENODEV;

	if (tty->flags & (1 << TTY_IO_ERROR))
		return -EIO;

	control = info->MCR;
	local_irq_disable();
	status = serial_in(info, UART_MSR);
	local_irq_enable();
	result =  ((control & UART_MCR_RTS) ? TIOCM_RTS : 0)
		| ((control & UART_MCR_DTR) ? TIOCM_DTR : 0)
#ifdef TIOCM_OUT1
		| ((control & UART_MCR_OUT1) ? TIOCM_OUT1 : 0)
		| ((control & UART_MCR_OUT2) ? TIOCM_OUT2 : 0)
#endif
		| ((status  & UART_MSR_DCD) ? TIOCM_CAR : 0)
		| ((status  & UART_MSR_RI) ? TIOCM_RNG : 0)
		| ((status  & UART_MSR_DSR) ? TIOCM_DSR : 0)
		| ((status  & UART_MSR_CTS) ? TIOCM_CTS : 0);
#endif
	return result;
}

static int rs_360_tiocmset(struct tty_struct *tty, struct file *file,
			   unsigned int set, unsigned int clear)
{
#ifdef modem_control
	ser_info_t *info = (ser_info_t *)tty->driver_data;
 	unsigned int arg;

	if (serial_paranoia_check(info, tty->name, __FUNCTION__))
		return -ENODEV;

	if (tty->flags & (1 << TTY_IO_ERROR))
		return -EIO;

 	if (set & TIOCM_RTS)
 		info->mcr |= UART_MCR_RTS;
 	if (set & TIOCM_DTR)
 		info->mcr |= UART_MCR_DTR;
	if (clear & TIOCM_RTS)
		info->MCR &= ~UART_MCR_RTS;
	if (clear & TIOCM_DTR)
		info->MCR &= ~UART_MCR_DTR;

#ifdef TIOCM_OUT1
	if (set & TIOCM_OUT1)
		info->MCR |= UART_MCR_OUT1;
	if (set & TIOCM_OUT2)
		info->MCR |= UART_MCR_OUT2;
	if (clear & TIOCM_OUT1)
		info->MCR &= ~UART_MCR_OUT1;
	if (clear & TIOCM_OUT2)
		info->MCR &= ~UART_MCR_OUT2;
#endif

	local_irq_disable();
	serial_out(info, UART_MCR, info->MCR);
	local_irq_enable();
#endif
	return 0;
}

/* Sending a break is a two step process on the SMC/SCC.  It is accomplished
 * by sending a STOP TRANSMIT command followed by a RESTART TRANSMIT
 * command.  We take advantage of the begin/end functions to make this
 * happen.
 */
static ushort	smc_chan_map[] = {
	CPM_CR_CH_SMC1,
	CPM_CR_CH_SMC2
};

static ushort	scc_chan_map[] = {
	CPM_CR_CH_SCC1,
	CPM_CR_CH_SCC2,
	CPM_CR_CH_SCC3,
	CPM_CR_CH_SCC4
};

static void begin_break(ser_info_t *info)
{
	volatile QUICC *cp;
	ushort	chan;
	int     idx;

	cp = pquicc;

	idx = PORT_NUM(info->state->smc_scc_num);
	if (info->state->smc_scc_num & NUM_IS_SCC)
		chan = scc_chan_map[idx];
	else
		chan = smc_chan_map[idx];

	cp->cp_cr = mk_cr_cmd(chan, CPM_CR_STOP_TX) | CPM_CR_FLG;
	while (cp->cp_cr & CPM_CR_FLG);
}

static void end_break(ser_info_t *info)
{
	volatile QUICC *cp;
	ushort	chan;
	int idx;

	cp = pquicc;

	idx = PORT_NUM(info->state->smc_scc_num);
	if (info->state->smc_scc_num & NUM_IS_SCC)
		chan = scc_chan_map[idx];
	else
		chan = smc_chan_map[idx];

	cp->cp_cr = mk_cr_cmd(chan, CPM_CR_RESTART_TX) | CPM_CR_FLG;
	while (cp->cp_cr & CPM_CR_FLG);
}

/*
 * This routine sends a break character out the serial port.
 */
static void send_break(ser_info_t *info, unsigned int duration)
{
#ifdef SERIAL_DEBUG_SEND_BREAK
	printk("rs_send_break(%d) jiff=%lu...", duration, jiffies);
#endif
	begin_break(info);
	msleep_interruptible(duration);
	end_break(info);
#ifdef SERIAL_DEBUG_SEND_BREAK
	printk("done jiffies=%lu\n", jiffies);
#endif
}


static int rs_360_ioctl(struct tty_struct *tty, struct file * file,
		    unsigned int cmd, unsigned long arg)
{
	int error;
	ser_info_t *info = (ser_info_t *)tty->driver_data;
	int retval;
	struct async_icount cnow; 
	/* struct async_icount_24 cnow;*/ 	/* kernel counter temps */
	struct serial_icounter_struct *p_cuser;	/* user space */

	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
		return -ENODEV;

	if ((cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
		if (tty->flags & (1 << TTY_IO_ERROR))
		    return -EIO;
	}
	
	switch (cmd) {
		case TCSBRK:	/* SVID version: non-zero arg --> no break */
			retval = tty_check_change(tty);
			if (retval)
				return retval;
			tty_wait_until_sent(tty, 0);
			if (signal_pending(current))
				return -EINTR;
			if (!arg) {
				send_break(info, 250);	/* 1/4 second */
				if (signal_pending(current))
					return -EINTR;
			}
			return 0;
		case TCSBRKP:	/* support for POSIX tcsendbreak() */
			retval = tty_check_change(tty);
			if (retval)
				return retval;
			tty_wait_until_sent(tty, 0);
			if (signal_pending(current))
				return -EINTR;
			send_break(info, arg ? arg*100 : 250);
			if (signal_pending(current))
				return -EINTR;
			return 0;
		case TIOCSBRK:
			retval = tty_check_change(tty);
			if (retval)
				return retval;
			tty_wait_until_sent(tty, 0);
			begin_break(info);
			return 0;
		case TIOCCBRK:
			retval = tty_check_change(tty);
			if (retval)
				return retval;
			end_break(info);
			return 0;
		case TIOCGSOFTCAR:
			/* return put_user(C_CLOCAL(tty) ? 1 : 0, (int *) arg); */
			put_user(C_CLOCAL(tty) ? 1 : 0, (int *) arg);
			return 0;
		case TIOCSSOFTCAR:
			error = get_user(arg, (unsigned int *) arg); 
			if (error)
				return error;
			tty->termios->c_cflag =
				((tty->termios->c_cflag & ~CLOCAL) |
				 (arg ? CLOCAL : 0));
			return 0;
#ifdef maybe
		case TIOCSERGETLSR: /* Get line status register */
			return get_lsr_info(info, (unsigned int *) arg);
#endif
		/*
		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
		 * - mask passed in arg for lines of interest
 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
		 * Caller should use TIOCGICOUNT to see which one it was
		 */
		 case TIOCMIWAIT:
#ifdef modem_control
			local_irq_disable();
			/* note the counters on entry */
			cprev = info->state->icount;
			local_irq_enable();
			while (1) {
				interruptible_sleep_on(&info->delta_msr_wait);
				/* see if a signal did it */
				if (signal_pending(current))
					return -ERESTARTSYS;
				local_irq_disable();
				cnow = info->state->icount; /* atomic copy */
				local_irq_enable();
				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
					return -EIO; /* no change => error */
				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
					return 0;
				}
				cprev = cnow;
			}
			/* NOTREACHED */
#else
			return 0;
#endif

		/* 
		 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
		 * Return: write counters to the user passed counter struct
		 * NB: both 1->0 and 0->1 transitions are counted except for
		 *     RI where only 0->1 is counted.
		 */
		case TIOCGICOUNT:
			local_irq_disable();
			cnow = info->state->icount;
			local_irq_enable();
			p_cuser = (struct serial_icounter_struct *) arg;
/* 			error = put_user(cnow.cts, &p_cuser->cts); */
/* 			if (error) return error; */
/* 			error = put_user(cnow.dsr, &p_cuser->dsr); */
/* 			if (error) return error; */
/* 			error = put_user(cnow.rng, &p_cuser->rng); */
/* 			if (error) return error; */
/* 			error = put_user(cnow.dcd, &p_cuser->dcd); */
/* 			if (error) return error; */

			put_user(cnow.cts, &p_cuser->cts);
			put_user(cnow.dsr, &p_cuser->dsr);
			put_user(cnow.rng, &p_cuser->rng);
			put_user(cnow.dcd, &p_cuser->dcd);
			return 0;

		default:
			return -ENOIOCTLCMD;
		}
	return 0;
}

/* FIX UP modem control here someday......
*/
static void rs_360_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;

	change_speed(info);

#ifdef modem_control
	/* Handle transition to B0 status */
	if ((old_termios->c_cflag & CBAUD) &&
	    !(tty->termios->c_cflag & CBAUD)) {
		info->MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
		local_irq_disable();
		serial_out(info, UART_MCR, info->MCR);
		local_irq_enable();
	}
	
	/* Handle transition away from B0 status */
	if (!(old_termios->c_cflag & CBAUD) &&
	    (tty->termios->c_cflag & CBAUD)) {
		info->MCR |= UART_MCR_DTR;
		if (!tty->hw_stopped ||
		    !(tty->termios->c_cflag & CRTSCTS)) {
			info->MCR |= UART_MCR_RTS;
		}
		local_irq_disable();
		serial_out(info, UART_MCR, info->MCR);
		local_irq_enable();
	}
	
	/* Handle turning off CRTSCTS */
	if ((old_termios->c_cflag & CRTSCTS) &&