riotty.c

来自「LINUX 2.6.17.4的源码」· C语言 代码 · 共 655 行 · 第 1/2 页

				/*
				   tp->tm.c_state &= ~WOPEN;
				 */
				PortP->State &= ~RIO_WOPEN;
				rio_spin_unlock_irqrestore(&PortP->portSem, flags);
				func_exit();
				return -EINTR;
			}
		}
		PortP->State &= ~RIO_WOPEN;
	}
	if (p->RIOHalted)
		goto bombout;
	rio_dprintk(RIO_DEBUG_TTY, "Setting RIO_MOPEN\n");
	PortP->State |= RIO_MOPEN;

	if (p->RIOHalted)
		goto bombout;

	rio_dprintk(RIO_DEBUG_TTY, "high level open done\n");

	/*
	 ** Count opens for port statistics reporting
	 */
	if (PortP->statsGather)
		PortP->opens++;

	rio_spin_unlock_irqrestore(&PortP->portSem, flags);
	rio_dprintk(RIO_DEBUG_TTY, "Returning from open\n");
	func_exit();
	return 0;
}

/*
** RIOClose the port.
** The operating system thinks that this is last close for the device.
** As there are two interfaces to the port (Modem and tty), we need to
** check that both are closed before we close the device.
*/
int riotclose(void *ptr)
{
	struct Port *PortP = ptr;	/* pointer to the port structure */
	int deleted = 0;
	int try = -1;		/* Disable the timeouts by setting them to -1 */
	int repeat_this = -1;	/* Congrats to those having 15 years of
				   uptime! (You get to break the driver.) */
	unsigned long end_time;
	struct tty_struct *tty;
	unsigned long flags;
	int rv = 0;

	rio_dprintk(RIO_DEBUG_TTY, "port close SysPort %d\n", PortP->PortNum);

	/* PortP = p->RIOPortp[SysPort]; */
	rio_dprintk(RIO_DEBUG_TTY, "Port is at address %p\n", PortP);
	/* tp = PortP->TtyP; *//* Get tty */
	tty = PortP->gs.tty;
	rio_dprintk(RIO_DEBUG_TTY, "TTY is at address %p\n", tty);

	if (PortP->gs.closing_wait)
		end_time = jiffies + PortP->gs.closing_wait;
	else
		end_time = jiffies + MAX_SCHEDULE_TIMEOUT;

	rio_spin_lock_irqsave(&PortP->portSem, flags);

	/*
	 ** Setting this flag will make any process trying to open
	 ** this port block until we are complete closing it.
	 */
	PortP->State |= RIO_CLOSING;

	if ((PortP->State & RIO_DELETED)) {
		rio_dprintk(RIO_DEBUG_TTY, "Close on deleted RTA\n");
		deleted = 1;
	}

	if (p->RIOHalted) {
		RIOClearUp(PortP);
		rv = -EIO;
		goto close_end;
	}

	rio_dprintk(RIO_DEBUG_TTY, "Clear bits\n");
	/*
	 ** clear the open bits for this device
	 */
	PortP->State &= ~RIO_MOPEN;
	PortP->State &= ~RIO_CARR_ON;
	PortP->ModemState &= ~MSVR1_CD;
	/*
	 ** If the device was open as both a Modem and a tty line
	 ** then we need to wimp out here, as the port has not really
	 ** been finally closed (gee, whizz!) The test here uses the
	 ** bit for the OTHER mode of operation, to see if THAT is
	 ** still active!
	 */
	if ((PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
		/*
		 ** The port is still open for the other task -
		 ** return, pretending that we are still active.
		 */
		rio_dprintk(RIO_DEBUG_TTY, "Channel %d still open !\n", PortP->PortNum);
		PortP->State &= ~RIO_CLOSING;
		if (PortP->firstOpen)
			PortP->firstOpen--;
		rio_spin_unlock_irqrestore(&PortP->portSem, flags);
		return -EIO;
	}

	rio_dprintk(RIO_DEBUG_TTY, "Closing down - everything must go!\n");

	PortP->State &= ~RIO_DYNOROD;

	/*
	 ** This is where we wait for the port
	 ** to drain down before closing. Bye-bye....
	 ** (We never meant to do this)
	 */
	rio_dprintk(RIO_DEBUG_TTY, "Timeout 1 starts\n");

	if (!deleted)
		while ((PortP->InUse != NOT_INUSE) && !p->RIOHalted && (PortP->TxBufferIn != PortP->TxBufferOut)) {
			if (repeat_this-- <= 0) {
				rv = -EINTR;
				rio_dprintk(RIO_DEBUG_TTY, "Waiting for not idle closed broken by signal\n");
				RIOPreemptiveCmd(p, PortP, FCLOSE);
				goto close_end;
			}
			rio_dprintk(RIO_DEBUG_TTY, "Calling timeout to flush in closing\n");
			rio_spin_unlock_irqrestore(&PortP->portSem, flags);
			if (RIODelay_ni(PortP, HUNDRED_MS * 10) == RIO_FAIL) {
				rio_dprintk(RIO_DEBUG_TTY, "RTA EINTR in delay \n");
				rv = -EINTR;
				rio_spin_lock_irqsave(&PortP->portSem, flags);
				goto close_end;
			}
			rio_spin_lock_irqsave(&PortP->portSem, flags);
		}

	PortP->TxBufferIn = PortP->TxBufferOut = 0;
	repeat_this = 0xff;

	PortP->InUse = 0;
	if ((PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
		/*
		 ** The port has been re-opened for the other task -
		 ** return, pretending that we are still active.
		 */
		rio_dprintk(RIO_DEBUG_TTY, "Channel %d re-open!\n", PortP->PortNum);
		PortP->State &= ~RIO_CLOSING;
		rio_spin_unlock_irqrestore(&PortP->portSem, flags);
		if (PortP->firstOpen)
			PortP->firstOpen--;
		return -EIO;
	}

	if (p->RIOHalted) {
		RIOClearUp(PortP);
		goto close_end;
	}

	/* Can't call RIOShortCommand with the port locked. */
	rio_spin_unlock_irqrestore(&PortP->portSem, flags);

	if (RIOShortCommand(p, PortP, CLOSE, 1, 0) == RIO_FAIL) {
		RIOPreemptiveCmd(p, PortP, FCLOSE);
		goto close_end;
	}

	if (!deleted)
		while (try && (PortP->PortState & PORT_ISOPEN)) {
			try--;
			if (time_after(jiffies, end_time)) {
				rio_dprintk(RIO_DEBUG_TTY, "Run out of tries - force the bugger shut!\n");
				RIOPreemptiveCmd(p, PortP, FCLOSE);
				break;
			}
			rio_dprintk(RIO_DEBUG_TTY, "Close: PortState:ISOPEN is %d\n", PortP->PortState & PORT_ISOPEN);

			if (p->RIOHalted) {
				RIOClearUp(PortP);
				goto close_end;
			}
			if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
				rio_dprintk(RIO_DEBUG_TTY, "RTA EINTR in delay \n");
				RIOPreemptiveCmd(p, PortP, FCLOSE);
				break;
			}
		}
	rio_spin_lock_irqsave(&PortP->portSem, flags);
	rio_dprintk(RIO_DEBUG_TTY, "Close: try was %d on completion\n", try);

	/* RIOPreemptiveCmd(p, PortP, FCLOSE); */

/*
** 15.10.1998 ARG - ESIL 0761 part fix
** RIO has it's own CTSFLOW and RTSFLOW flags in 'Config' in the port structure,** we need to make sure that the flags are clear when the port is opened.
*/
	PortP->Config &= ~(RIO_CTSFLOW | RIO_RTSFLOW);

	/*
	 ** Count opens for port statistics reporting
	 */
	if (PortP->statsGather)
		PortP->closes++;

close_end:
	/* XXX: Why would a "DELETED" flag be reset here? I'd have
	   thought that a "deleted" flag means that the port was
	   permanently gone, but here we can make it reappear by it
	   being in close during the "deletion".
	 */
	PortP->State &= ~(RIO_CLOSING | RIO_DELETED);
	if (PortP->firstOpen)
		PortP->firstOpen--;
	rio_spin_unlock_irqrestore(&PortP->portSem, flags);
	rio_dprintk(RIO_DEBUG_TTY, "Return from close\n");
	return rv;
}



static void RIOClearUp(struct Port *PortP)
{
	rio_dprintk(RIO_DEBUG_TTY, "RIOHalted set\n");
	PortP->Config = 0;	/* Direct semaphore */
	PortP->PortState = 0;
	PortP->firstOpen = 0;
	PortP->FlushCmdBodge = 0;
	PortP->ModemState = PortP->CookMode = 0;
	PortP->Mapped = 0;
	PortP->WflushFlag = 0;
	PortP->MagicFlags = 0;
	PortP->RxDataStart = 0;
	PortP->TxBufferIn = 0;
	PortP->TxBufferOut = 0;
}

/*
** Put a command onto a port.
** The PortPointer, command, length and arg are passed.
** The len is the length *inclusive* of the command byte,
** and so for a command that takes no data, len==1.
** The arg is a single byte, and is only used if len==2.
** Other values of len aren't allowed, and will cause
** a panic.
*/
int RIOShortCommand(struct rio_info *p, struct Port *PortP, int command, int len, int arg)
{
	struct PKT *PacketP;
	int retries = 20;	/* at 10 per second -> 2 seconds */
	unsigned long flags;

	rio_dprintk(RIO_DEBUG_TTY, "entering shortcommand.\n");

	if (PortP->State & RIO_DELETED) {
		rio_dprintk(RIO_DEBUG_TTY, "Short command to deleted RTA ignored\n");
		return RIO_FAIL;
	}
	rio_spin_lock_irqsave(&PortP->portSem, flags);

	/*
	 ** If the port is in use for pre-emptive command, then wait for it to
	 ** be free again.
	 */
	while ((PortP->InUse != NOT_INUSE) && !p->RIOHalted) {
		rio_dprintk(RIO_DEBUG_TTY, "Waiting for not in use (%d)\n", retries);
		rio_spin_unlock_irqrestore(&PortP->portSem, flags);
		if (retries-- <= 0) {
			return RIO_FAIL;
		}
		if (RIODelay_ni(PortP, HUNDRED_MS) == RIO_FAIL) {
			return RIO_FAIL;
		}
		rio_spin_lock_irqsave(&PortP->portSem, flags);
	}
	if (PortP->State & RIO_DELETED) {
		rio_dprintk(RIO_DEBUG_TTY, "Short command to deleted RTA ignored\n");
		rio_spin_unlock_irqrestore(&PortP->portSem, flags);
		return RIO_FAIL;
	}

	while (!can_add_transmit(&PacketP, PortP) && !p->RIOHalted) {
		rio_dprintk(RIO_DEBUG_TTY, "Waiting to add short command to queue (%d)\n", retries);
		rio_spin_unlock_irqrestore(&PortP->portSem, flags);
		if (retries-- <= 0) {
			rio_dprintk(RIO_DEBUG_TTY, "out of tries. Failing\n");
			return RIO_FAIL;
		}
		if (RIODelay_ni(PortP, HUNDRED_MS) == RIO_FAIL) {
			return RIO_FAIL;
		}
		rio_spin_lock_irqsave(&PortP->portSem, flags);
	}

	if (p->RIOHalted) {
		rio_spin_unlock_irqrestore(&PortP->portSem, flags);
		return RIO_FAIL;
	}

	/*
	 ** set the command byte and the argument byte
	 */
	writeb(command, &PacketP->data[0]);

	if (len == 2)
		writeb(arg, &PacketP->data[1]);

	/*
	 ** set the length of the packet and set the command bit.
	 */
	writeb(PKT_CMD_BIT | len, &PacketP->len);

	add_transmit(PortP);
	/*
	 ** Count characters transmitted for port statistics reporting
	 */
	if (PortP->statsGather)
		PortP->txchars += len;

	rio_spin_unlock_irqrestore(&PortP->portSem, flags);
	return p->RIOHalted ? RIO_FAIL : ~RIO_FAIL;
}