uart.c

优龙2410linux2.6.8内核源代码

	 * the break.  If not, we exit now, losing the break.  FIXME
	 */
	if ((tty->flip.count + 1) >= TTY_FLIPBUF_SIZE)
		return;
	*(tty->flip.flag_buf_ptr++) = TTY_BREAK;
	*(tty->flip.char_buf_ptr++) = 0;
	tty->flip.count++;

	queue_task(&tty->flip.tqueue, &tq_timer);
}

static _INLINE_ void transmit_chars(ser_info_t *info, struct pt_regs *regs)
{

	if ((info->flags & TX_WAKEUP) ||
	    (info->tty->flags & (1 << TTY_DO_WRITE_WAKEUP))) {
		rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
	}

#ifdef SERIAL_DEBUG_INTR
	printk("THRE...");
#endif
}

#ifdef notdef
	/* I need to do this for the SCCs, so it is left as a reminder.
	*/
static _INLINE_ void check_modem_status(struct async_struct *info)
{
	int	status;
	struct	async_icount *icount;

	status = serial_in(info, UART_MSR);

	if (status & UART_MSR_ANY_DELTA) {
		icount = &info->state->icount;
		/* update input line counters */
		if (status & UART_MSR_TERI)
			icount->rng++;
		if (status & UART_MSR_DDSR)
			icount->dsr++;
		if (status & UART_MSR_DDCD) {
			icount->dcd++;
#ifdef CONFIG_HARD_PPS
			if ((info->flags & ASYNC_HARDPPS_CD) &&
			    (status & UART_MSR_DCD))
				hardpps();
#endif
		}
		if (status & UART_MSR_DCTS)
			icount->cts++;
		wake_up_interruptible(&info->delta_msr_wait);
	}

	if ((info->flags & ASYNC_CHECK_CD) && (status & UART_MSR_DDCD)) {
#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
		printk("ttys%d CD now %s...", info->line,
		       (status & UART_MSR_DCD) ? "on" : "off");
#endif
		if (status & UART_MSR_DCD)
			wake_up_interruptible(&info->open_wait);
		else {
#ifdef SERIAL_DEBUG_OPEN
			printk("scheduling hangup...");
#endif
			schedule_task(&info->tqueue_hangup);
		}
	}
	if (info->flags & ASYNC_CTS_FLOW) {
		if (info->tty->hw_stopped) {
			if (status & UART_MSR_CTS) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
				printk("CTS tx start...");
#endif
				info->tty->hw_stopped = 0;
				info->IER |= UART_IER_THRI;
				serial_out(info, UART_IER, info->IER);
				rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
				return;
			}
		} else {
			if (!(status & UART_MSR_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
				printk("CTS tx stop...");
#endif
				info->tty->hw_stopped = 1;
				info->IER &= ~UART_IER_THRI;
				serial_out(info, UART_IER, info->IER);
			}
		}
	}
}
#endif

/*
 * This is the serial driver's interrupt routine for a single port
 */
static void rs_8xx_interrupt(void *dev_id, struct pt_regs *regs)
{
	u_char	events;
	int	idx;
	ser_info_t *info;
	volatile smc_t	*smcp;
	volatile scc_t	*sccp;

	info = (ser_info_t *)dev_id;

	idx = PORT_NUM(info->state->smc_scc_num);
	if (info->state->smc_scc_num & NUM_IS_SCC) {
		sccp = &cpmp->cp_scc[idx];
		events = sccp->scc_scce;
		if (events & SMCM_BRKE)
			receive_break(info, regs);
		if (events & SCCM_RX)
			receive_chars(info, regs);
		if (events & SCCM_TX)
			transmit_chars(info, regs);
		sccp->scc_scce = events;
	}
	else {
		smcp = &cpmp->cp_smc[idx];
		events = smcp->smc_smce;
		if (events & SMCM_BRKE)
			receive_break(info, regs);
		if (events & SMCM_RX)
			receive_chars(info, regs);
		if (events & SMCM_TX)
			transmit_chars(info, regs);
		smcp->smc_smce = events;
	}

#ifdef SERIAL_DEBUG_INTR
	printk("rs_interrupt_single(%d, %x)...",
					info->state->smc_scc_num, events);
#endif
#ifdef modem_control
	check_modem_status(info);
#endif
	info->last_active = jiffies;
#ifdef SERIAL_DEBUG_INTR
	printk("end.\n");
#endif
}


/*
 * -------------------------------------------------------------------
 * Here ends the serial interrupt routines.
 * -------------------------------------------------------------------
 */

/*
 * This routine is used to handle the "bottom half" processing for the
 * serial driver, known also the "software interrupt" processing.
 * This processing is done at the kernel interrupt level, after the
 * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON.  This
 * is where time-consuming activities which can not be done in the
 * interrupt driver proper are done; the interrupt driver schedules
 * them using rs_sched_event(), and they get done here.
 */
static void do_serial_bh(void)
{
	run_task_queue(&tq_serial);
}

static void do_softint(void *private_)
{
	ser_info_t	*info = (ser_info_t *) private_;
	struct tty_struct	*tty;

	tty = info->tty;
	if (!tty)
		return;

	if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event)) {
		if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
		    tty->ldisc.write_wakeup)
			(tty->ldisc.write_wakeup)(tty);
		wake_up_interruptible(&tty->write_wait);
	}
}

/*
 * This routine is called from the scheduler tqueue when the interrupt
 * routine has signalled that a hangup has occurred.  The path of
 * hangup processing is:
 *
 * 	serial interrupt routine -> (scheduler tqueue) ->
 * 	do_serial_hangup() -> tty->hangup() -> rs_hangup()
 *
 */
static void do_serial_hangup(void *private_)
{
	struct async_struct	*info = (struct async_struct *) private_;
	struct tty_struct	*tty;

	tty = info->tty;
	if (tty)
		tty_hangup(tty);
}

/*static void rs_8xx_timer(void)
{
	printk("rs_8xx_timer\n");
}*/


static int startup(ser_info_t *info)
{
	unsigned long flags;
	int	retval=0;
	int	idx;
	struct serial_state *state= info->state;
	volatile smc_t		*smcp;
	volatile scc_t		*sccp;
	volatile smc_uart_t	*up;
	volatile scc_uart_t	*scup;


	save_flags(flags); cli();

	if (info->flags & ASYNC_INITIALIZED) {
		goto errout;
	}

#ifdef maybe
	if (!state->port || !state->type) {
		if (info->tty)
			set_bit(TTY_IO_ERROR, &info->tty->flags);
		goto errout;
	}
#endif

#ifdef SERIAL_DEBUG_OPEN
	printk("starting up ttys%d (irq %d)...", info->line, state->irq);
#endif


#ifdef modem_control
	info->MCR = 0;
	if (info->tty->termios->c_cflag & CBAUD)
		info->MCR = UART_MCR_DTR | UART_MCR_RTS;
#endif

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

	/*
	 * and set the speed of the serial port
	 */
	change_speed(info);

	idx = PORT_NUM(info->state->smc_scc_num);
	if (info->state->smc_scc_num & NUM_IS_SCC) {
		sccp = &cpmp->cp_scc[idx];
		scup = (scc_uart_t *)&cpmp->cp_dparam[state->port];
		scup->scc_genscc.scc_mrblr = RX_BUF_SIZE;
		scup->scc_maxidl = RX_BUF_SIZE;
		sccp->scc_sccm |= (UART_SCCM_TX | UART_SCCM_RX);
		sccp->scc_gsmrl |= (SCC_GSMRL_ENR | SCC_GSMRL_ENT);
	}
	else {
		smcp = &cpmp->cp_smc[idx];

		/* Enable interrupts and I/O.
		*/
		smcp->smc_smcm |= (SMCM_RX | SMCM_TX);
		smcp->smc_smcmr |= (SMCMR_REN | SMCMR_TEN);

		/* We can tune the buffer length and idle characters
		 * to take advantage of the entire incoming buffer size.
		 * If mrblr is something other than 1, maxidl has to be
		 * non-zero or we never get an interrupt.  The maxidl
		 * is the number of character times we wait after reception
		 * of the last character before we decide no more characters
		 * are coming.
		 */
		up = (smc_uart_t *)&cpmp->cp_dparam[state->port];
		up->smc_mrblr = RX_BUF_SIZE;
		up->smc_maxidl = RX_BUF_SIZE;
		up->smc_brkcr = 1;	/* number of break chars */
	}

	info->flags |= ASYNC_INITIALIZED;
	restore_flags(flags);
	return 0;

errout:
	restore_flags(flags);
	return retval;
}

/*
 * This routine will shutdown a serial port; interrupts are disabled, and
 * DTR is dropped if the hangup on close termio flag is on.
 */
static void shutdown(ser_info_t * info)
{
	unsigned long	flags;
	struct serial_state *state;
	int		idx;
	volatile smc_t	*smcp;
	volatile scc_t	*sccp;

	if (!(info->flags & ASYNC_INITIALIZED))
		return;

	state = info->state;

#ifdef SERIAL_DEBUG_OPEN
	printk("Shutting down serial port %d (irq %d)....", info->line,
	       state->irq);
#endif

	save_flags(flags); cli(); /* Disable interrupts */

	idx = PORT_NUM(state->smc_scc_num);
	if (state->smc_scc_num & NUM_IS_SCC) {
		sccp = &cpmp->cp_scc[idx];
		sccp->scc_gsmrl &= ~(SCC_GSMRL_ENR | SCC_GSMRL_ENT);
#ifdef CONFIG_SERIAL_CONSOLE
		/* We can't disable the transmitter if this is the
		 * system console.
		 */
		if ((state - rs_table) != CONFIG_SERIAL_CONSOLE_PORT)
#endif
			sccp->scc_sccm &= ~(UART_SCCM_TX | UART_SCCM_RX);
	}
	else {
		smcp = &cpmp->cp_smc[idx];

		/* Disable interrupts and I/O.
		*/
		smcp->smc_smcm &= ~(SMCM_RX | SMCM_TX);
#ifdef CONFIG_SERIAL_CONSOLE
		/* We can't disable the transmitter if this is the
		 * system console.
		 */
		if ((state - rs_table) != CONFIG_SERIAL_CONSOLE_PORT)
#endif
			smcp->smc_smcmr &= ~(SMCMR_REN | SMCMR_TEN);
	}

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

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

/*
 * This routine is called to set the UART divisor registers to match
 * the specified baud rate for a serial port.
 */
static void change_speed(ser_info_t *info)
{
	int	baud_rate;
	unsigned cflag, cval, scval, prev_mode, new_mode;
	int	i, bits, sbits, idx;
	unsigned long	flags;
	struct serial_state *state;
	volatile smc_t	*smcp;
	volatile scc_t	*sccp;

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

	state = info->state;

	/* Character length programmed into the mode register is the
	 * sum of: 1 start bit, number of data bits, 0 or 1 parity bit,
	 * 1 or 2 stop bits, minus 1.
	 * The value 'bits' counts this for us.
	 */
	cval = 0;
	scval = 0;

	/* byte size and parity */
	switch (cflag & CSIZE) {
	      case CS5: bits = 5; break;
	      case CS6: bits = 6; break;
	      case CS7: bits = 7; break;
	      case CS8: bits = 8; break;
	      /* Never happens, but GCC is too dumb to figure it out */
	      default:  bits = 8; break;
	}
	sbits = bits - 5;

	if (cflag & CSTOPB) {
		cval |= SMCMR_SL;	/* Two stops */
		scval |= SCU_PMSR_SL;
		bits++;
	}
	if (cflag & PARENB) {
		cval |= SMCMR_PEN;
		scval |= SCU_PMSR_PEN;
		bits++;
		if (!(cflag & PARODD)) {
			cval |= SMCMR_PM_EVEN;
			scval |= (SCU_PMSR_REVP | SCU_PMSR_TEVP);
		}
	}

	/* Determine divisor based on baud rate */
	i = cflag & CBAUD;
	if (i >= (sizeof(baud_table)/sizeof(int)))
		baud_rate = 9600;
	else
		baud_rate = baud_table[i];

	info->timeout = (TX_BUF_SIZE*HZ*bits);
	info->timeout += HZ/50;		/* Add .02 seconds of slop */

#ifdef modem_control
	/* CTS flow control flag and modem status interrupts */
	info->IER &= ~UART_IER_MSI;
	if (info->flags & ASYNC_HARDPPS_CD)
		info->IER |= UART_IER_MSI;
	if (cflag & CRTSCTS) {
		info->flags |= ASYNC_CTS_FLOW;
		info->IER |= UART_IER_MSI;
	} else
		info->flags &= ~ASYNC_CTS_FLOW;
	if (cflag & CLOCAL)
		info->flags &= ~ASYNC_CHECK_CD;
	else {
		info->flags |= ASYNC_CHECK_CD;
		info->IER |= UART_IER_MSI;
	}
	serial_out(info, UART_IER, info->IER);
#endif

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

	info->read_status_mask = (BD_SC_EMPTY | BD_SC_OV);
	if (I_INPCK(info->tty))
		info->read_status_mask |= BD_SC_FR | BD_SC_PR;
	if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
		info->read_status_mask |= BD_SC_BR;

	/*
	 * Characters to ignore
	 */
	info->ignore_status_mask = 0;
	if (I_IGNPAR(info->tty))
		info->ignore_status_mask |= BD_SC_PR | BD_SC_FR;
	if (I_IGNBRK(info->tty)) {
		info->ignore_status_mask |= BD_SC_BR;
		/*
		 * If we're ignore parity and break indicators, ignore
		 * overruns too.  (For real raw support).
		 */
		if (I_IGNPAR(info->tty))
			info->ignore_status_mask |= BD_SC_OV;
	}
	/*
	 * !!! ignore all characters if CREAD is not set
	 */
	if ((cflag & CREAD) == 0)
		info->read_status_mask &= ~BD_SC_EMPTY;
	save_flags(flags); cli();

	/* Start bit has not been added (so don't, because we would just
	 * subtract it later), and we need to add one for the number of
	 * stops bits (there is always at least one).
	 */
	bits++;
	idx = PORT_NUM(state->smc_scc_num);
	if (state->smc_scc_num & NUM_IS_SCC) {
		sccp = &cpmp->cp_scc[idx];
		new_mode = (sbits << 12) | scval;
		prev_mode = sccp->scc_pmsr;
		if (!(prev_mode & SCU_PMSR_PEN))
			/* If parity is disabled, mask out even/odd */
			prev_mode &= ~(SCU_PMSR_TPM|SCU_PMSR_RPM);
		if (prev_mode != new_mode)
			sccp->scc_pmsr = new_mode;
	}
	else {
		smcp = &cpmp->cp_smc[idx];

		/* Set the mode register.  We want to keep a copy of the
		 * enables, because we want to put them back if they were
		 * present.
		 */
		prev_mode = smcp->smc_smcmr;
		new_mode = smcr_mk_clen(bits) | cval |  SMCMR_SM_UART;
		new_mode |= (prev_mode & (SMCMR_REN | SMCMR_TEN));
		if (!(prev_mode & SMCMR_PEN))
			/* If parity is disabled, mask out even/odd */
			prev_mode &= ~SMCMR_PM_EVEN;
		if (prev_mode != new_mode)
			smcp->smc_smcmr = new_mode;
	}

	m8xx_cpm_setbrg((state - rs_table), baud_rate);

	restore_flags(flags);
}

static void rs_8xx_put_char(struct tty_struct *tty, unsigned char ch)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;
	volatile cbd_t	*bdp;
	unsigned char *cp;

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

	if (!tty)
		return;

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

	cp = info->tx_va_base + ((bdp - info->tx_bd_base) * TX_BUF_SIZE);